Commercialization of Seizure Prediction Technology Promises and Pitfalls of Biosignal Analysis: Seizure Prediction and Management (A case study);

DTIC Science & Technology

2001-10-25

control system depicted in Fig. 1. It consists of an implantable neurostimulator (INS) containing electronics, a communication antenna and circuitry... Neurostimulation Business, Medtronic, Inc. Minneapolis, MN 55421 Report Documentation Page Report Date 25 Oct 2001 Report Type N/A Dates Covered (from... to...Organization Name(s) and Address(es) Technical Fellow, Neurostimulation Business, Medtronic, Inc Minneapolis, MN 55421 Performing Organization Report

Methods to Analyze Bone Regenerative Response to Different rhBMP-2 Doses in Rabbit Craniofacial Defects

DTIC Science & Technology

2014-02-28

sockets.6 The commercially available INFUSE system (Medtronic Spinal and Biologics, Memphis, TN), compris- ing an absorbable collagen sponge plus...a collagen sponge carrier) by Medtronics27 for bone healing in rabbits. Even the 25mg rhBMP-2 dose used showed significantly greater re- generated...visualization No 3D morphological analysis for small-animal modelsCan be repeated over course of healing for temporal trends Potential risk of X-ray

Medtronic, Inc.; premarket approval of the Interstim Sacral Nerve Stimulation (SNS) System--FDA. Notice.

PubMed

1998-01-29

The Food and Drug Administration (FDA) is announcing its approval of the application by Medtronic, Inc., Minneapolis, MN, for premarket approval, under the Federal Food, Drug, and Cosmetic Act (the act), of the Interstim Sacral Nerve Stimulation (SNS) System. After reviewing the recommendation of the Gastroenterology and Urology Devices Panel, FDA's Center for Devices and Radiological Health (CDRH) notified the applicant, by letter of September 29, 1997, of the approval of the application.

Evaluation of subcutaneous glucose monitoring systems under routine environmental conditions in patients with type 1 diabetes.

PubMed

Aberer, Felix; Hajnsek, Martin; Rumpler, Markus; Zenz, Sabine; Baumann, Petra M; Elsayed, Hesham; Puffing, Adelheid; Treiber, Gerlies; Pieber, Thomas R; Sourij, Harald; Mader, Julia K

2017-07-01

Continuous and flash glucose monitoring (GM) systems have been established in diabetes care. We compared the sensor performance of 3 commercially available GM systems. A total of 12 patients with type 1 diabetes were included in a single-centre, open-label study in which the sensor performance of the Abbott FreeStyle libre (Abbott), Dexcom G4 Platinum (Dexcom) and Medtronic MiniMed 640G (Medtronic) systems over 12 hours was compared during mimicked real-life conditions (meals, exercise, hypo- and hyperglycaemia). Sensor performance was determined by fulfilment of ISO 15197:2013 criteria, calculating mean absolute relative difference (MARD), and was also illustrated using Parkes error grid and Bland-Altman plots. Sensor performance during changes in metabolic variables (lactate, betahydroxybutyrate, glucagon, non-esterified-fatty-acids) was determined by Spearman's rank correlation coefficient testing. The systems fulfilled ISO 15197:2013 criteria by 73.2% (Abbott), 56.1% (Dexcom) and 52.0% (Medtronic). The MARDs ± standard deviation in the entire glycaemic range were 13.2% ± 10.9% (Abbott), 16.8% ± 12.3% (Dexcom) and 21.4% ± 17.6% (Medtronic), respectively. All sensors performed less accurately during hypoglycaemia and best during hyperglycaemia. We did not observe an influence of metabolic variables on sensor performance. © 2017 John Wiley & Sons Ltd.

Using Medtronic's MAST Quadrant, Radiance, and Radiance X Illumination Systems with high-power light sources increases burn risk.

PubMed

2010-11-01

Connecting the Medtronic MAST Quadrant Illumination System, Radiance Illumination System, or Radiance X Illumination System--all of which are specialized fiberoptic light cables used with the company's minimally invasive spinal products--to a high-power surgical light source significantly increases the risk of patient burns. Hospitals should ensure that the products are used only with 100 W light sources and 5 mm light cables, as prescribed in the product labeling.

Battery longevity in cardiac resynchronization therapy implantable cardioverter defibrillators.

PubMed

Alam, Mian Bilal; Munir, Muhammad Bilal; Rattan, Rohit; Flanigan, Susan; Adelstein, Evan; Jain, Sandeep; Saba, Samir

2014-02-01

Cardiac resynchronization therapy (CRT) implantable cardioverter defibrillators (ICDs) deliver high burden ventricular pacing to heart failure patients, which has a significant effect on battery longevity. The aim of this study was to investigate whether battery longevity is comparable for CRT-ICDs from different manufacturers in a contemporary cohort of patients. All the CRT-ICDs implanted at our institution from 1 January 2008 to 31 December 2010 were included in this analysis. Baseline demographic and clinical data were collected on all patients using the electronic medical record. Detailed device information was collected on all patients from scanned device printouts obtained during routine follow-up. The primary endpoint was device replacement for battery reaching the elective replacement indicator (ERI). A total of 646 patients (age 69 ± 13 years), implanted with CRT-ICDs (Boston Scientific 173, Medtronic 416, and St Jude Medical 57) were included in this analysis. During 2.7 ± 1.5 years follow-up, 113 (17%) devices had reached ERI (Boston scientific 4%, Medtronic 25%, and St Jude Medical 7%, P < 0.001). The 4-year survival rate of device battery was significantly worse for Medtronic devices compared with devices from other manufacturers (94% for Boston scientific, 67% for Medtronic, and 92% for St Jude Medical, P < 0.001). The difference in battery longevity by manufacturer was independent of pacing burden, lead parameters, and burden of ICD therapy. There are significant discrepancies in CRT-ICD battery longevity by manufacturer. These data have important implications on clinical practice and patient outcomes.

A Review and Analysis of the YODA Trials: What Can We Glean Clinically?

PubMed

Le, Michael E; Kurd, Mark F

2014-09-01

Medtronic's biologic, Infuse (rhBMP-2), was approved by the FDA in 2002. Since its approval, a whirlwind of controversy developed culminating in an investigation by the Senate Finance committee. These events led to a landmark agreement between Medtronic and Yale University to perform a comprehensive and unbiased analysis of all patient related data. The project was named the Yale Open Data Access (YODA). The purpose of this article is to evaluate the results of the YODA project and determine what is clinically meaningful.

Electromagnetic interference of endodontic equipments with cardiovascular implantable electronic device.

PubMed

Dadalti, Manoela Teixeira de Sant'Anna; da Cunha, Antônio José Ledo Alves; de Araújo, Marcos César Pimenta; de Moraes, Luis Gustavo Belo; Risso, Patrícia de Andrade

2016-03-01

Assess the electromagnetic interference (EMI) of endodontic equipment with cardiovascular implantable electronic devices (CIEDs) and related factors. The laser device, electronic apex locators (EAL), optical microscope, endodontic rotary motors, gutta-percha heat carrier (GH), gutta-percha gun and ultrasonic device were tested next to CIEDs (Medtronic and Biotronik) with varied sensitivity settings and distances. CIEDs were immersed in a saline solution to simulate the electrical resistence of the human body. The endodontic equipment was tested in both horizontal and vertical positions in relation to the components of the CIED. The tests were performed on a dental chair in order to assess the cumulative effect of electromagnetic fields. It was found no EMI with the Biotronik pacemaker. EALs caused EMI with Medtronic PM at a 2 cm distance, with the NSK(®) EAL also affecting the Medtronic defibrillator. GH caused EMI at 2 cm and 5 cm from the Medtronic defibrillator. EMI occurred when devices were horizontally positioned to the CIED. In the majority of the cases, EMI occurred when the pacemaker was set to maximum sensitivity. There was cumulative effect of electromagnetic fields between GH and dental chair. EALs and GH caused EMI which ranged according to type and sensitivity setting of the CIEDs and the distance. However, no endodontic equipment caused permanent damage to the CIED. The use of GH caused a cumulative effect of electromagnetic fields. It suggests that during the treatment of patients with CIEDs, only the necessary equipments should be kept turned on. Patients with CIEDs may be subject to EMI from electronic equipment used in dental offices, as they remain turned on throughout the treatment. This is the first article assessing the cumulative effect of electromagnetic fields. Copyright © 2016. Published by Elsevier Ltd.

Complications with the MICRA TPS Pacemaker System: Persistent Complete Heart Block and Late Capture Failure.

PubMed

Holm, Niels; Müller, Andreas; Zbinden, Rainer

2017-04-01

A Medtronic MICRA transcatheter pacing system (Medtronic, Minneapolis, MN, USA) was implanted in an 86-year-old patient with sick sinus syndrome and left bundle branch block after transfemoral aortic valve implantation. During implantation she developed a persistent complete heart block due to manipulation with the large-bore delivery catheter. Two weeks later, acute pacemaker dysfunction occurred due to massive increase of pacing threshold and impedance without obvious pacemaker dislocation or myocardial perforation. Recurrent capture failure was seen with pacing output set at 5 V/1.0 ms. Hence, microdislocation or fixation of the tines in the right ventricular trabeculae has to be assumed. © 2016 Wiley Periodicals, Inc.

Day and Night Closed-Loop Control Using the Integrated Medtronic Hybrid Closed-Loop System in Type 1 Diabetes at Diabetes Camp.

PubMed

Ly, Trang T; Roy, Anirban; Grosman, Benyamin; Shin, John; Campbell, Alex; Monirabbasi, Salman; Liang, Bradley; von Eyben, Rie; Shanmugham, Satya; Clinton, Paula; Buckingham, Bruce A

2015-07-01

To evaluate the feasibility and efficacy of a fully integrated hybrid closed-loop (HCL) system (Medtronic MiniMed Inc., Northridge, CA), in day and night closed-loop control in subjects with type 1 diabetes, both in an inpatient setting and during 6 days at diabetes camp. The Medtronic MiniMed HCL system consists of a fourth generation (4S) glucose sensor, a sensor transmitter, and an insulin pump using a modified proportional-integral-derivative (PID) insulin feedback algorithm with safety constraints. Eight subjects were studied over 48 h in an inpatient setting. This was followed by a study of 21 subjects for 6 days at diabetes camp, randomized to either the closed-loop control group using the HCL system or to the group using the Medtronic MiniMed 530G with threshold suspend (control group). The overall mean sensor glucose percent time in range 70-180 mg/dL was similar between the groups (73.1% vs. 69.9%, control vs. HCL, respectively) (P = 0.580). Meter glucose values between 70 and 180 mg/dL were also similar between the groups (73.6% vs. 63.2%, control vs. HCL, respectively) (P = 0.086). The mean absolute relative difference of the 4S sensor was 10.8 ± 10.2%, when compared with plasma glucose values in the inpatient setting, and 12.6 ± 11.0% compared with capillary Bayer CONTOUR NEXT LINK glucose meter values during 6 days at camp. In the first clinical study of this fully integrated system using an investigational PID algorithm, the system did not demonstrate improved glucose control compared with sensor-augmented pump therapy alone. The system demonstrated good connectivity and improved sensor performance. © 2015 by the American Diabetes Association. Readers may use this article as long as the work is properly cited, the use is educational and not for profit, and the work is not altered.

Clinical performance of different DF-4 implantable cardioverter defibrillator leads.

PubMed

Sarrazin, Jean-François; Philippon, François; Sellier, Romain; André, Philippe; O'Hara, Gilles; Molin, Franck; Nault, Isabelle; Blier, Louis; Champagne, Jean

2018-06-01

Implantable cardioverter-defibrillator (ICD) DF-4 connectors have been introduced to facilitate defibrillator lead connection and to reduce the size of device header. There are limited data regarding the overall performance of those leads and no comparison between different ICD DF-4 leads. This is a cohort study of consecutive patients implanted with ICD DF-4 lead system at one University Centre between October 2010 and February 2015. A historical control group of patients with ICD DF-1 lead implantation was used for comparison. The following ICD DF-4 leads were evaluated: St. Jude Medical Durata 7122Q (St. Jude Medical, St. Paul, MN, USA), Medtronic Sprint Quattro Secure 6935 M (Medtronic Inc., Minneapolis, MN, USA), Boston Scientific Endotak Reliance 4-Site 0293 (Boston Scientific, Marlborough, MA, USA), and Boston Scientific Reliance 4-Front 0693. This study evaluated the acute and mid-term performances of those leads as well as complications. A total of 812 patients (age 63 ± 12 years, 80% male, left ventricular ejection fraction 31 ± 12%) underwent implantation of an ICD DF-4 lead. Acute and follow-up R-wave sensing and threshold were excellent. Compared to implantation, intrinsic R waves were higher at follow-up for Boston Scientific and Medtronic leads, and pacing lead impedances were lower for all leads at first follow-up (P < 0.001). The number of lead dislodgement or failure was similar between all leads. The estimated lead survival rates at 3 years were 95.6% for Boston Scientific Endotak 4-Site, 97.1% for Boston Scientific 4-Front, 97.7% for Medtronic Sprint Quattro, and 97.5% for St. Jude Durata (P  =  0.553). All ICD DF-4 leads had excellent acute and mid-term electrical performances. Longer follow-up will be necessary to confirm their sustained performance. © 2018 Wiley Periodicals, Inc.

Optimized programming algorithm for cylindrical and directional deep brain stimulation electrodes.

PubMed

Anderson, Daria Nesterovich; Osting, Braxton; Vorwerk, Johannes; Dorval, Alan D; Butson, Christopher R

2018-04-01

Deep brain stimulation (DBS) is a growing treatment option for movement and psychiatric disorders. As DBS technology moves toward directional leads with increased numbers of smaller electrode contacts, trial-and-error methods of manual DBS programming are becoming too time-consuming for clinical feasibility. We propose an algorithm to automate DBS programming in near real-time for a wide range of DBS lead designs. Magnetic resonance imaging and diffusion tensor imaging are used to build finite element models that include anisotropic conductivity. The algorithm maximizes activation of target tissue and utilizes the Hessian matrix of the electric potential to approximate activation of neurons in all directions. We demonstrate our algorithm's ability in an example programming case that targets the subthalamic nucleus (STN) for the treatment of Parkinson's disease for three lead designs: the Medtronic 3389 (four cylindrical contacts), the direct STNAcute (two cylindrical contacts, six directional contacts), and the Medtronic-Sapiens lead (40 directional contacts). The optimization algorithm returns patient-specific contact configurations in near real-time-less than 10 s for even the most complex leads. When the lead was placed centrally in the target STN, the directional leads were able to activate over 50% of the region, whereas the Medtronic 3389 could activate only 40%. When the lead was placed 2 mm lateral to the target, the directional leads performed as well as they did in the central position, but the Medtronic 3389 activated only 2.9% of the STN. This DBS programming algorithm can be applied to cylindrical electrodes as well as novel directional leads that are too complex with modern technology to be manually programmed. This algorithm may reduce clinical programming time and encourage the use of directional leads, since they activate a larger volume of the target area than cylindrical electrodes in central and off-target lead placements.

Implantable loop recorders for assessment of syncope: increased diagnostic yield and less adverse outcomes with the latest generation devices.

PubMed

Bartoletti, A; Bocconcelli, P; De Santo, T; Ghidini Ottonelli, A; Giuli, S; Massa, R; Svetlich, C; Tarsi, G; Corbucci, G; Tronconi, F; Vitale, E

2013-08-01

Aim of the study was to compare the diagnostic yield of implantable loop recorders (ILR) of two successive generations for the assessment of syncope. Data on patients who had undergone ILR implantation for unexplained syncope in four Italian public hospitals were retrospectively acquired from the Medtronic Clinical Service database. After implantation, routine follow-up examinations were performed every 90 days, while urgent examinations were carried out in the event of syncope recurrence. The following findings were regarded as diagnostic: ECG documentation of a syncope recurrence; documentation of any of the arrhythmias listed by the current guidelines as diagnostic findings even if asymptomatic. Between November 2002 and March 2010, 107 patients received an ILR (40 Medtronic Reveal® Plus; 67 Medtronic Reveal® DX/XT) and underwent at least one follow-up examination. Diagnoses were made in 7 (17.5%) and 24 (35.8%) (P=0.043) patients, with a median time of 228 and 65 days, respectively. Three (42.9%) and 21 (87.5%) (P=0.029) diagnoses were based on automatically detected events, while adverse outcomes occurred in 6 and in 1 (P=0.01) patients, respectively. Our results show that the new-generation device offer a higher diagnostic yield, mainly as a result of its improved automatic detection function, and is associated with fewer adverse outcomes.

Electrical interference in non-competitive pacemakers

PubMed Central

Sowton, E.; Gray, K.; Preston, T.

1970-01-01

Patients with 41 implanted non-competitive pacemakers were investigated. A variety of domestic electrical equipment, a motor-car, and a physiotherapy diathermy apparatus were each operated in turn at various ranges from the patient. Interference effects on pacemaker function were assessed on the electrocardiograph. Medtronic demand 5841 pacemakers were stopped by diathermy while Cordis Ectocor pacemakers developed a fast discharge rate. Cordis triggered pacemakers (both Atricor and Ectocor) were sensitive to interference from many items of domestic equipment and the motor car. The Elema EM153 ran at an increased rate when an electric razor was running close to the pacemaker. The Devices demand 2980 and the Medtronic demand 5841 were not affected by the domestic equipment tested. The significance of interference effects is discussed in relation to pacemaker design. Images PMID:5470044

A Comparative Study of Defibrillator Leads at a Large-Volume Implanting Hospital: Results From the Pacemaker and Implantable Defibrillator Leads Survival Study ("PAIDLESS").

PubMed

Cohen, Todd J; Asheld, Wilbur J; Germano, Joseph; Islam, Shahidul; Patel, Dhimesh

2015-06-01

The purpose of the study was to examine survival in the implantable defibrillator subset of implanted leads at a large-volume implanting hospital. Implantable lead survival has been the subject of many multicenter studies over the past decade. Fewer large implanting volume single-hospital studies have examined defibrillator lead failure as it relates to patient survival and lead construction. This investigator-initiated retrospective study examined defibrillator lead failure in those who underwent implantation of a defibrillator between February 1, 1996 and December 31, 2011. Lead failure was defined as: failure to capture/sense, abnormal pacing and/or defibrillator impedance, visual insulation defect or lead fracture, extracardiac stimulation, cardiac perforation, tricuspid valve entrapment, lead tip fracture and/or lead dislodgment. Patient characteristics, implant approach, lead manufacturers, lead models, recalled status, patient mortality, and core lead design elements were compared using methods that include Kaplan Meier analysis, univariate and multivariable Cox regression models. A total of 4078 defibrillator leads were implanted in 3802 patients (74% male; n = 2812) with a mean age of 70 ± 13 years at Winthrop University Hospital. Lead manufacturers included: Medtronic: [n = 1834; 801 recalled]; St. Jude Medical: [n = 1707; 703 recalled]; Boston Scientific: [n = 537; 0 recalled]. Kaplan-Meier analysis adjusted for multiple comparisons revealed that both Boston Scientific's and St. Jude Medical's leads had better survival than Medtronic's leads (P<.001 and P=.01, respectively). Lead survival was comparable between Boston Scientific and St. Jude Medical (P=.80). A total of 153 leads failed (3.5% of all leads) during the study. There were 99 lead failures from Medtronic (5.4% failure rate); 56 were recalled Sprint Fidelis leads. There were 36 lead failures from St. Jude (2.1% failure rate); 20 were recalled Riata or Riata ST leads. There were 18 lead failures from Boston Scientific (3.35% failure rate); none were recalled. Kaplan Meier analysis also showed lead failure occurred sooner in the recalled leads (P=.01). A total of 1493 patients died during the study (mechanism of death was largely unknown). There was a significant increase in mortality in the recalled lead group as compared with non-recalled leads (P=.01), but no significant difference in survival when comparing recalled leads from Medtronic with St. Jude Medical (P=.67). A multivariable Cox regression model revealed younger age, history of percutaneous coronary intervention, baseline rhythm other than atrial fibrillation or atrial flutter, combination polyurethane and silicone lead insulation, a second defibrillation coil, and recalled lead status all contributed to lead failure. This study demonstrated a significantly improved lead performance in the Boston Scientific and St. Jude leads as compared with Medtronic leads. Some lead construction variables (insulation and number of coils) also had a significant impact on lead failure, which was independent of the manufacturer. Recalled St. Jude leads performed better than recalled Medtronic leads in our study. Recalled St. Jude leads had no significant difference in lead failure when compared with the other manufacturer's non-recalled leads. Defibrillator recalled lead status was associated with an increased mortality as compared with non-recalled leads. This correlation was independent of the lead manufacturer and clinically significant even when considering known mortality risk factors. These results must be tempered by the largely unknown mechanism of death in these patients.

The Integrity bare-metal stent made by continuous sinusoid technology.

PubMed

Turco, Mark A

2011-05-01

The Integrity Coronary Stent System (Medtronic Vascular, CA, USA) is a low-profile, open-cell, cobalt-chromium-alloy advanced bare-metal iteration of the well-known Driver/Micro-Driver Coronary Stent System (Medtronic Vascular). The Integrity stent is made with a process called continuous sinusoid technology. This process allows stent construction via wrapping a single thin strand of wire around a mandrel in a sinusoid configuration, with laser fusion of adjacent crowns. The wire-forming process and fusion pattern provide the stent with a continuous preferential bending plane, intended to allow easier access to, and smoother tracking within, distal and tortuous vessels while radial strength is maintained. Continuous sinusoid technology represents innovation in the design of stent platforms and will provide a future stent platform for newer technology, including drug-eluting stent platforms, drug-filled stents and core wire stents.

Bioprosthetic Aortic Valve Durability: A Meta-Regression of Published Studies.

PubMed

Wang, Mansen; Furnary, Anthony P; Li, Hsin-Fang; Grunkemeier, Gary L

2017-09-01

To compare structural valve deterioration (SVD) among bioprosthetic aortic valve types, a PubMed search found 54 papers containing SVD-free curves extending to at least 10 years. The curves were digitized and fit to Weibull distributions, and the mean times to valve failure (MTTF) were calculated. Twelve valve models were collapsed into four valve types: Medtronic (Medtronic, Minneapolis, MN) and Edwards (Edwards Lifesciences, Irvine, CA) porcine; and Sorin (Sorin Group [now LivaNova], London, United Kingdom) and Edwards pericardial. Meta-regression found MTTF was associated with the patient's age, publication year, SVD definition, and valve type. Sorin pericardial valves had significantly lower risk-adjusted MTTF (higher SVD risk), and there were no significant differences in MTTF among the other three valve types. Copyright © 2017 The Society of Thoracic Surgeons. Published by Elsevier Inc. All rights reserved.

Incidence and management of prolonged charge times in the Medtronic model 7219 implantable cardioverter defibrillator.

PubMed

Mann, D E; Gleason, S A; Kelly, P A; Easley, A R; Reiter, M J

2001-06-01

The Medtronic Jewel PCD model 7219, introduced in 1994, was the first downsized, pectoral implantable cardioverter defibrillator (ICD), and many of these units are approaching or have reached the elective replacement indicator (ERI). Unlike later Medtronic ICDs and most other ICDs, in which ERI is defined by battery voltage, the ERI in the model 7219 series is defined when either the capacitor charge time to full output is repeatedly> or =14.5 s or when battery voltage is< or =4.91 V. In this study we examined which of the two ERI criteria was met first in patients with this device model. We also assessed the effects of manual dumping and recharging and of increasing the automatic capacitor reformation frequency on prolonged charge times. In 16 patients with follow-up <2 years, 15 reached the charge time ERI before battery voltage ERI. Manual dumping and recharging led to spuriously low charge times due to residual charge at the start of recharging, and increasing the automatic capacitor reformation frequency to once a month did not decrease prolonged charge times. Because of persistently prolonged charge times, 15 patients had generator changes. None of these patients had reached battery voltage ERI (battery voltage at time of explantation 5.06+/-0.06 V). Thus in this early pectoral device, prolonged charge times occur commonly before battery voltage ERI is reached. Whether prolonged charge times will have an impact on device longevity in later model ICDs is unknown.

Acute obstruction by Pannus in patients with aortic medtronic-hall valves: 30 years of experience.

PubMed

Ellensen, Vegard Skalstad; Andersen, Knut Sverre; Vitale, Nicola; Davidsen, Einar Skulstad; Segadal, Leidulf; Haaverstad, Rune

2013-12-01

Acute dysfunction of mechanical aortic valve prostheses is a life-threatening adverse event. Pannus overgrowth, which is fibroelastic hyperplasia originating from the periannular area, is one cause of dysfunction. The aim of this study was to determine the annual incidence of readmittance resulting from acute obstruction caused by pannus during 30 years of observation in patients with Medtronic-Hall aortic valve prostheses and to analyze the risk factors associated with pannus development. From 1982 to 2004, 1,187 patients in our department underwent aortic valve replacement with Medtronic-Hall mechanical monoleaflet valve prostheses. As of December 31, 2012, 27 of these patients (2.3%) had presented with acute valve dysfunction caused by pannus obstruction. The annual incidence of pannus was 0.7 per 1,000. The median time from the primary operation to prosthetic dysfunction was 11.1 years (range, 1.2 to 26.8 years). Of the 20 patients who underwent reoperation, 2 died. Seven patients died before reoperation. Women had a higher risk for the development of obstructing pannus, and patients with pannus obstruction were younger. Valve size was not an independent risk factor. Women and younger patients are at higher risk for pannus development. When acute dysfunction by pannus is suspected in a mechanical aortic valve, an immediate echocardiogram and an emergency aortic valve replacement should be carried out because of the potential of a fatal outcome. Copyright © 2013 The Society of Thoracic Surgeons. Published by Elsevier Inc. All rights reserved.

Observation of cavitation in a mechanical heart valve in a total artificial heart.

PubMed

Lee, Hwansung; Tsukiya, Tomonori; Homma, Akihiko; Kamimura, Tadayuki; Takewa, Yoshiaki; Nishinaka, Tomohiro; Tatsumi, Eisuke; Taenaka, Yoshiyuki; Takano, Hisateru; Kitamura, Soichiro

2004-01-01

Recently, cavitation on the surface of mechanical heart valves has been studied as a cause of fractures occurring in implanted mechanical heart valves. The cause of cavitation in mechanical heart valves was investigated using the 25 mm Medtronic Hall valve and the 23 mm Omnicarbon valve. Closing of these valves in the mitral position was simulated in an electrohydraulic totally artificial heart. Tests were conducted under physiologic pressures at heart rates from 60 to 100 beats per minute with cardiac outputs from 4.8 to 7.7 L/min. The disk closing motion was measured by a laser displacement sensor. A high-speed video camera was used to observe the cavitation bubbles in the mechanical heart valves. The maximum closing velocity of the Omnicarbon valve was faster than that of the Medtronic Hall valve. In both valves, the closing velocity of the leaflet, used as the cavitation threshold, was approximately 1.3-1.5 m/s. In the case of the Medtronic Hall valve, cavitation bubbles were generated by the squeeze flow and by the effects of the venturi and the water hammer. With the Omnicarbon valve, the cavitation bubbles were generated by the squeeze flow and the water hammer. The mechanism leading to the development of cavitation bubbles depended on the valve closing velocity and the valve stop geometry. Most of the cavitation bubbles were observed around the valve stop and were generated by the squeeze flow.

Multicenter Study Validating Accuracy of a Continuous Respiratory Rate Measurement Derived From Pulse Oximetry: A Comparison With Capnography.

PubMed

Bergese, Sergio D; Mestek, Michael L; Kelley, Scott D; McIntyre, Robert; Uribe, Alberto A; Sethi, Rakesh; Watson, James N; Addison, Paul S

2017-04-01

Intermittent measurement of respiratory rate via observation is routine in many patient care settings. This approach has several inherent limitations that diminish the clinical utility of these measurements because it is intermittent, susceptible to human error, and requires clinical resources. As an alternative, a software application that derives continuous respiratory rate measurement from a standard pulse oximeter has been developed. We sought to determine the performance characteristics of this new technology by comparison with clinician-reviewed capnography waveforms in both healthy subjects and hospitalized patients in a low-acuity care setting. Two independent observational studies were conducted to validate the performance of the Medtronic Nellcor Respiration Rate Software application. One study enrolled 26 healthy volunteer subjects in a clinical laboratory, and a second multicenter study enrolled 53 hospitalized patients. During a 30-minute study period taking place while participants were breathing spontaneously, pulse oximeter and nasal/oral capnography waveforms were collected. Pulse oximeter waveforms were processed to determine respiratory rate via the Medtronic Nellcor Respiration Rate Software. Capnography waveforms reviewed by a clinician were used to determine the reference respiratory rate. A total of 23,243 paired observations between the pulse oximeter-derived respiratory rate and the capnography reference method were collected and examined. The mean reference-based respiratory rate was 15.3 ± 4.3 breaths per minute with a range of 4 to 34 breaths per minute. The Pearson correlation coefficient between the Medtronic Nellcor Respiration Rate Software values and the capnography reference respiratory rate is reported as a linear correlation, R, as 0.92 ± 0.02 (P < .001), whereas Lin's concordance correlation coefficient indicates an overall agreement of 0.85 ± 0.04 (95% confidence interval [CI] +0.76; +0.93) (healthy volunteers: 0.94 ± 0.02 [95% CI +0.91; +0.97]; hospitalized patients: 0.80 ± 0.06 [95% CI +0.68; +0.92]). The mean bias of the Medtronic Nellcor Respiration Rate Software was 0.18 breaths per minute with a precision (SD) of 1.65 breaths per minute (healthy volunteers: 0.37 ± 0.78 [95% limits of agreement: -1.16; +1.90] breaths per minute; hospitalized patients: 0.07 ± 1.99 [95% limits of agreement: -3.84; +3.97] breaths per minute). The root mean square deviation was 1.35 breaths per minute (healthy volunteers: 0.81; hospitalized patients: 1.60). These data demonstrate the performance of the Medtronic Nellcor Respiration Rate Software in healthy subjects and patients hospitalized in a low-acuity care setting when compared with clinician-reviewed capnography. The observed performance of this technology suggests that it may be a useful adjunct to continuous pulse oximetry monitoring by providing continuous respiratory rate measurements. The potential patient safety benefit of using combined continuous pulse oximetry and respiratory rate monitoring warrants assessment.

Multicenter Study Validating Accuracy of a Continuous Respiratory Rate Measurement Derived From Pulse Oximetry: A Comparison With Capnography

PubMed Central

Bergese, Sergio D.; Kelley, Scott D.; McIntyre, Robert; Uribe, Alberto A.; Sethi, Rakesh; Watson, James N.; Addison, Paul S.

2017-01-01

BACKGROUND: Intermittent measurement of respiratory rate via observation is routine in many patient care settings. This approach has several inherent limitations that diminish the clinical utility of these measurements because it is intermittent, susceptible to human error, and requires clinical resources. As an alternative, a software application that derives continuous respiratory rate measurement from a standard pulse oximeter has been developed. We sought to determine the performance characteristics of this new technology by comparison with clinician-reviewed capnography waveforms in both healthy subjects and hospitalized patients in a low-acuity care setting. METHODS: Two independent observational studies were conducted to validate the performance of the Medtronic NellcorTM Respiration Rate Software application. One study enrolled 26 healthy volunteer subjects in a clinical laboratory, and a second multicenter study enrolled 53 hospitalized patients. During a 30-minute study period taking place while participants were breathing spontaneously, pulse oximeter and nasal/oral capnography waveforms were collected. Pulse oximeter waveforms were processed to determine respiratory rate via the Medtronic Nellcor Respiration Rate Software. Capnography waveforms reviewed by a clinician were used to determine the reference respiratory rate. RESULTS: A total of 23,243 paired observations between the pulse oximeter-derived respiratory rate and the capnography reference method were collected and examined. The mean reference-based respiratory rate was 15.3 ± 4.3 breaths per minute with a range of 4 to 34 breaths per minute. The Pearson correlation coefficient between the Medtronic Nellcor Respiration Rate Software values and the capnography reference respiratory rate is reported as a linear correlation, R, as 0.92 ± 0.02 (P < .001), whereas Lin’s concordance correlation coefficient indicates an overall agreement of 0.85 ± 0.04 (95% confidence interval [CI] +0.76; +0.93) (healthy volunteers: 0.94 ± 0.02 [95% CI +0.91; +0.97]; hospitalized patients: 0.80 ± 0.06 [95% CI +0.68; +0.92]). The mean bias of the Medtronic Nellcor Respiration Rate Software was 0.18 breaths per minute with a precision (SD) of 1.65 breaths per minute (healthy volunteers: 0.37 ± 0.78 [95% limits of agreement: –1.16; +1.90] breaths per minute; hospitalized patients: 0.07 ± 1.99 [95% limits of agreement: –3.84; +3.97] breaths per minute). The root mean square deviation was 1.35 breaths per minute (healthy volunteers: 0.81; hospitalized patients: 1.60). CONCLUSIONS: These data demonstrate the performance of the Medtronic Nellcor Respiration Rate Software in healthy subjects and patients hospitalized in a low-acuity care setting when compared with clinician-reviewed capnography. The observed performance of this technology suggests that it may be a useful adjunct to continuous pulse oximetry monitoring by providing continuous respiratory rate measurements. The potential patient safety benefit of using combined continuous pulse oximetry and respiratory rate monitoring warrants assessment. PMID:28099286

Effect of steroid eluting versus conventional electrodes on propafenone induced rise in chronic ventricular pacing threshold.

PubMed

Cornacchia, D; Fabbri, M; Maresta, A; Nigro, P; Sorrentino, F; Puglisi, A; Ricci, R; Peraldo, C; Fazzari, M; Pistis, G

1993-12-01

The aim of this study was to evaluate chronic ventricular pacing threshold increase after oral propafenone therapy. Eighty-three patients affected by advanced atrioventricular block and sick sinus syndrome were studied at least 3 months after pacemaker implantation, before and after oral propafenone therapy (450-900 mg/day based on body weight). The patients were subdivided into three groups according to the type of unipolar electrode that was implanted: group I (41 patients) Medtronic CapSure 4003, group II (30 patients) Medtronic Target Tip 4011, and group III (12 patients) Osypka Vy screw-in lead. In all cases a Medtronic unipolar pacemaker was implanted: 30 Minix, 23 Activitrax, 14 Elite, 12 Legend, and 4 Pasys. Propafenone blood level was measured in 75 patients 3-5 hours after propafenone administration. The pacing autothreshold was measured at 0.8 V, 1.6 V, and 2.5 V by reducing pulse width. At the three different outputs before and after propafenone, threshold increments were significantly lower in group I in comparison with group II and group III (propafenone ranging from < 0.001 to < 0.05). No significant difference was found in pacing impedance or in propafenone plasma concentration in the three groups. Strength-duration curves were drawn for each group at baseline and after propafenone administration. Before propafenone, in group I, the knee was markedly shifted to the left and downward as compared to the classic curve, so that the steep part was predominant; in group II and group III this shift was progressively less evident.(ABSTRACT TRUNCATED AT 250 WORDS)

75 FR 38532 - Medical Devices; Availability of Safety and Effectiveness Summaries for Premarket Approval...

Federal Register 2010, 2011, 2012, 2013, 2014

2010-07-02

... LLIAC March 5, FDA-2010-M-0135 Scientific PREMOUNTED STENT SYSTEM 2010 Corp. P090006 Medtronic COMPLETE SE VASCULAR March 17, FDA-2010-M-0158 Vascular STENT SYSTEM 2010 II. Electronic Access Persons with...

77 FR 70480 - Investigations Regarding Certifications of Eligibility To Apply for Worker Adjustment Assistance

Federal Register 2010, 2011, 2012, 2013, 2014

2012-11-26

... Ludington, MI......... 11/01/12 10/31/12 Company (Company). 82123 Medtronic (State/One-Stop). Mounds View... Ray Boats (State/One-Stop). 82125 Honeywell, Inc. (Workers).. Mars Hill, NC......... 11/02/12 10/24/12...

Performance comparison of the medtronic sof-sensor and enlite glucose sensors in inpatient studies of individuals with type 1 diabetes.

PubMed

Calhoun, Peter; Lum, John; Beck, Roy W; Kollman, Craig

2013-09-01

Knowledge of the accuracy of continuous glucose monitoring (CGM) devices is important for its use as a management tool for individuals with diabetes and for its use to assess outcomes in clinical studies. Using data from several inpatient studies, we compared the accuracy of two sensors, the Medtronic Enlite™ using MiniMed Paradigm(®) Veo™ calibration and the Sof-Sensor(®) glucose sensor using Guardian(®) REAL-Time CGM calibration (all from Medtronic Diabetes, Northridge, CA). Nocturnal data were analyzed from eight inpatient studies in which both CGM and reference glucose measurements were available. The analyses included 1,666 CGM-reference paired glucose values for the Enlite in 54 participants over 69 nights and 3,627 paired values for the Sof-Sensor in 66 participants over 91 nights. The Enlite sensor tended to report glucose levels lower than the reference over the entire range of glucose values, whereas the Sof-Sensor values tended to be higher than reference values in the hypoglycemic range and lower than reference values in the hyperglycemic range. The overall median sensor-reference difference was -15 mg/dL for the Enlite and -1 mg/dL for the Sof-Sensor (P<0.001). The median relative absolute difference was 15% for the Enlite versus 12% for the Sof-Sensor (P=0.06); 66% of Enlite values and 73% of Sof-Sensor values met International Organization for Standardization criteria. We found that the Enlite tended to be biased low over the entire glucose range, whereas the Sof-Sensor showed the more typical sensor pattern of being biased high in the hypoglycemic range and biased low in the hyperglycemic range.

Early Performance and Safety of the Micra Transcatheter Pacemaker in Pigs.

PubMed

Bonner, Matthew; Eggen, Michael; Haddad, Tarek; Sheldon, Todd; Williams, Eric

2015-11-01

The Micra® Transcatheter Pacing System (TPS; Medtronic Inc., Minneapolis, MN, USA) is a miniaturized single-chamber pacemaker system that is delivered via catheter through the femoral vein. In this study, the electrical performance was compared between the TPS and a traditional leaded pacemaker. In addition, the safety profile of the two systems was compared by thorough monitoring for a number of adverse events. The TPS was implanted in the right ventricular apex of 10 Yucatan mini pigs and a Medtronic single-lead pacemaker (SLP) was implanted in the right ventricular apex of another 10 pigs and connected to a traditional pacemaker. The electrical performance of all devices was monitored for 12 weeks. The safety profile of each system was characterized using x-ray, computed tomography, ultrasound, blood work, and necropsy to monitor for a variety of adverse events. At implant the mean pacing thresholds were 0.58 ± 0.17 V @0.24 ms and 0.75 ± 0.29 V @0.21 ms for the TPS and the SLP respectively. After 12 weeks, mean thresholds were 0.94 ± 0.46 V and 1.85 ± 0.75 V (P < 0.0001). There were two pulmonary emboli that were small and past the tertiary branch, and one occurred in each arm. There were also two infections with one in each arm. There were no dislodgements (macro or micro), tissue injury, tamponade, or valve injury. Overall, despite the 10-fold size reduction of the Micra TPS, it appears to perform similarly and have a similar safety profile to a traditional pacemaker system. © 2015 Medtronic PLC. Pacing and Clinical Electrophysiology published by Wiley Periodicals, Inc.

Case report and review of the literature total endovascular repair of acute ascending aortic rupture: a case report and review of the literature.

PubMed

McCallum, John C; Limmer, Karl K; Perricone, Anthony; Bandyk, Dennis; Kansal, Nikhil

2013-07-01

Thoracic aortic endografting has been successfully implemented to treat aneurysmal disease of the distal aortic arch and descending thoracic aorta. Although there are reports of ascending aortic endovascular interventions, the total endovascular repair of a ruptured ascending aorta secondary to a Type A dissection has not been described. We report the case of a 77-year-old patient who presented with a ruptured ascending aortic aneurysm secondary to degeneration of a Stanford type A aortic dissection. His surgical history was significant for orthotropic heart transplant 19 years prior. The dissection, aneurysm, and rupture occurred in the native aorta distal to the ascending aortic suture line. At presentation, he was hemodynamically unstable with a right hemothorax. We placed 3 Medtronic Talent Thoracic Stent Graft devices (Medtronic Inc, Minneapolis, MN) across the suture line in the ascending aorta, excluding the rupture. The patient survived and has been followed to 25 months.

Cavitation behavior observed in three monoleaflet mechanical heart valves under accelerated testing conditions.

PubMed

Lo, Chi-Wen; Liu, Jia-Shing; Li, Chi-Pei; Lu, Po-Chien; Hwang, Ned H

2008-01-01

Accelerated testing provides a substantial amount of data on mechanical heart valve durability in a short period of time, but such conditions may not accurately reflect in vivo performance. Cavitation, which occurs during mechanical heart valve closure when local flow field pressure decreases below vapor pressure, is thought to play a role in valve damage under accelerated conditions. The underlying flow dynamics and mechanisms behind cavitation bubble formation are poorly understood. Under physiologic conditions, random perivalvular cavitation is difficult to capture. We applied accelerated testing at a pulse rate of 600 bpm and transvalvular pressure of 120 mm Hg, with synchronized videographs and high-frequency pressure measurements, to study cavitation of the Medtronic Hall Standard (MHS), Medtronic Hall D-16 (MHD), and Omni Carbon (OC) valves. Results showed cavitation bubbles between 340 and 360 micros after leaflet/housing impact of the MHS, MHD, and OC valves, intensified by significant leaflet rebound. Squeeze flow, Venturi, and water hammer effects each contributed to cavitation, depending on valve design.

Medtronic Freestyle aortic bioprosthesis: a potential option for haemodialysis patients†.

PubMed

Hegazy, Yasser Y; Rayan, Amr; Sodian, Ralf; Hassanein, Wael; Ennker, Jürgen

2016-04-01

End-stage renal disease patients on regular haemodialysis are at higher risk of calcification. Therefore, many surgeons have concerns regarding the implantation of bioprostheses in such patients. The haemodynamic advantages of stentless aortic bioprostheses support their use; however, these have not been studied yet in end-stage renal disease patients. We studied accordingly the early and mid-term outcomes of aortic valve replacement (AVR) using Medtronic Freestyle stentless aortic bioprostheses in this subset of patients in comparison with stented aortic bioprostheses. We retrospectively studied two groups of consecutive patients on regular haemodialysis who required AVR between 2007 and 2013. Non-Freestyle (NFS) group received stented aortic bioprostheses (36 patients) and Freestyle (FS) group received Medtronic Freestyle aortic bioprostheses (48 patients). Follow-up ranged from 2 to 76 months with a mean follow-up of 36.3 ± 25 months. Patients in both groups showed similar demographic characters regarding age (76.4 ± 8.1 vs 74.9 ± 7.2 years; P = 0.35), male gender (58 vs 60%; P = 0.57) and diabetes mellitus (42 vs 48%; P = 0.57). Smaller aortic bioprostheses were implanted in the NFS (23.3 ± 1.2 vs 25.4 ± 2.1; P < 0.001) with consequently higher postoperative mean gradients (14.1 ± 4.1 vs 11.9 ± 5.3 mmHg; P = 0.004). No significant differences were noted regarding postoperative neurological disorder (8 vs 12%; P = 0.73), deep sternal wound infection (3 vs 4%; P = 0.68), re-exploration (8 vs 8%; P = 0.91) and in-hospital mortality (6 vs 4%; P = 0.92). Mid-term follow-up showed higher prosthetic valve calcification and/or sclerosis in NFS group (25 vs 6%; P = 0.015), whereas no significant differences were noticed between the two groups regarding stroke (0 vs 8%; P = 0.13), endocarditis (0 vs 4%; P = 0.50), 36- and 72-month survival (51 ± 2%, 14 ± 4% vs 55 ± 2%, 19 ± 3%, respectively; P = 0.45). Aortic bioprostheses are a good option for haemodialysis patients requiring AVR, offering acceptable mid-term survival. The Medtronic Freestyle aortic bioprostheses could allow the implantation of larger bioprostheses inferring consequently lower mean gradients, with a potentially higher resistance to calcification and sclerosis in haemodialysis patients. © The Author 2016. Published by Oxford University Press on behalf of the European Association for Cardio-Thoracic Surgery. All rights reserved.

Wenckebach upper rate response in single chamber pacemaker.

PubMed

Barold, S S

2000-07-01

The Medtronic Minix pacemaker during normal function in the VVT mode was found to exhibit a Wenckenbach upper rate response similar to that of dual chamber devices. This behavior occurred only when the upper rate interval was longer than the pacemaker refractory period. In a single chamber device this response may simulate pacemaker malfunction.

78 FR 17415 - Medical Devices; Availability of Safety and Effectiveness Summaries for Premarket Approval...

Federal Register 2010, 2011, 2012, 2013, 2014

2013-03-21

..., FDA-2012-M-1012 Bolton Medical Inc... Relay[supreg] September 21, 2012. Thoracic Stent-Graft with Plus........ Ovation Abdominal October 5, 2012. Stent Graft System. P120007, FDA-2012-M-1066 Gen-Probe, Inc........ Medtronic Vascular... Valiant[supreg] October 26, 2012. Thoracic Stent Graft with the Captivia Delivery...

75 FR 4407 - The Neurological Devices Panel of the Medical Devices Advisory Committee; Notice of Meeting

Federal Register 2010, 2011, 2012, 2013, 2014

2010-01-27

... premarket approval application for the Deep Brain Stimulation System for Epilepsy sponsored by Medtronic...-onset seizures (affecting only a part of the brain when they begin), with or without secondary... a partial-onset seizure that later spreads to the whole brain. ``Refractory'' to antiepileptic...

Selective interference with pacemaker activity by electrical dental devices.

PubMed

Miller, C S; Leonelli, F M; Latham, E

1998-01-01

We sought to determine whether electromagnetic interference with cardiac pacemakers occurs during the operation of contemporary electrical dental equipment. Fourteen electrical dental devices were tested in vitro for their ability to interfere with the function of two Medtronics cardiac pacemakers (one a dual-chamber, bipolar Thera 7942 pacemaker, the other a single-chamber, unipolar Minix 8340 pacemaker). Atrial and ventricular pacemaker output and electrocardiographic activity were monitored by means of telemetry with the use of a Medtronics 9760/90 programmer. Atrial and ventricular pacing were inhibited by electromagnetic interference produced by the electrosurgical unit up to a distance of 10 cm, by the ultrasonic bath cleaner up to 30 cm, and by the magnetorestrictive ultrasonic scalers up to 37.5 cm. In contrast, operation of the amalgamator, electric pulp tester, composite curing light, dental handpieces, electric toothbrush, microwave oven, dental chair and light, ENAC ultrasonic instrument, radiography unit, and sonic scaler did not alter pacing rate or rhythm. These results suggest that certain electrosurgical and ultrasonic instruments may produce deleterious effects in medically fragile patients with cardiac pacemakers.

Failing stentless Bioprostheses in patients with carcinoid heart valve disease.

PubMed

Schaefer, Andreas; Sill, Bjoern; Schoenebeck, Jeannette; Schneeberger, Yvonne; Reichenspurner, Hermann; Gulbins, Helmut

2015-03-27

Carcinoid tumor with consecutive endocardial fibroelastosis of the right heart, known as carcinoid heart valve disease (CHVD) or Hedinger's syndrome, is accompanied by combined right-sided valvular dysfunction with regurgitation and stenosis of the affected valves. Cardiac surgery with replacement of the tricuspid and/or pulmonary valve is an established therapeutic option for patients with Hedinger's syndrome. Little is known about the long term outcome and the choice of prosthesis for the pulmonal position is still a matter of debate. The authors report three cases of pulmonary valve replacement with stentless bioprostheses (Medtronic Freestyle, Medtronic PLC, Minneapolis, MN, USA) due to severe pulmonary valve degeneration in consequence of Hedinger's syndrome. All patients presented with re-stenosis of the pulmonal valve conduit at the height of the anastomoses in a premature fashion. Due to the increased risk for repeat surgical valve replacement, two patients were treated by transcatheter heart valves. We do not recommend the replacement of the pulmonary valve with stentless bioprostheses in patients with CHVD. These valves presented with an extreme premature degeneration and consecutive re-stenosis and heart failure.

Automated hybrid closed-loop control with a proportional-integral-derivative based system in adolescents and adults with type 1 diabetes: individualizing settings for optimal performance.

PubMed

Ly, Trang T; Weinzimer, Stuart A; Maahs, David M; Sherr, Jennifer L; Roy, Anirban; Grosman, Benyamin; Cantwell, Martin; Kurtz, Natalie; Carria, Lori; Messer, Laurel; von Eyben, Rie; Buckingham, Bruce A

2017-08-01

Automated insulin delivery systems, utilizing a control algorithm to dose insulin based upon subcutaneous continuous glucose sensor values and insulin pump therapy, will soon be available for commercial use. The objective of this study was to determine the preliminary safety and efficacy of initialization parameters with the Medtronic hybrid closed-loop controller by comparing percentage of time in range, 70-180 mg/dL (3.9-10 mmol/L), mean glucose values, as well as percentage of time above and below target range between sensor-augmented pump therapy and hybrid closed-loop, in adults and adolescents with type 1 diabetes. We studied an initial cohort of 9 adults followed by a second cohort of 15 adolescents, using the Medtronic hybrid closed-loop system with the proportional-integral-derivative with insulin feed-back (PID-IFB) algorithm. Hybrid closed-loop was tested in supervised hotel-based studies over 4-5 days. The overall mean percentage of time in range (70-180 mg/dL, 3.9-10 mmol/L) during hybrid closed-loop was 71.8% in the adult cohort and 69.8% in the adolescent cohort. The overall percentage of time spent under 70 mg/dL (3.9 mmol/L) was 2.0% in the adult cohort and 2.5% in the adolescent cohort. Mean glucose values were 152 mg/dL (8.4 mmol/L) in the adult cohort and 153 mg/dL (8.5 mmol/L) in the adolescent cohort. Closed-loop control using the Medtronic hybrid closed-loop system enables adaptive, real-time basal rate modulation. Initializing hybrid closed-loop in clinical practice will involve individualizing initiation parameters to optimize overall glucose control. © 2016 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Videoexoscopic real-time intraoperative navigation for spinal neurosurgery: a novel co-adaptation of two existing technology platforms, technical note.

PubMed

Huang, Meng; Barber, Sean Michael; Steele, William James; Boghani, Zain; Desai, Viren Rajendrakumar; Britz, Gavin Wayne; West, George Alexander; Trask, Todd Wilson; Holman, Paul Joseph

2018-06-01

Image-guided approaches to spinal instrumentation and interbody fusion have been widely popularized in the last decade [1-5]. Navigated pedicle screws are significantly less likely to breach [2, 3, 5, 6]. Navigation otherwise remains a point reference tool because the projection is off-axis to the surgeon's inline loupe or microscope view. The Synaptive robotic brightmatter drive videoexoscope monitor system represents a new paradigm for off-axis high-definition (HD) surgical visualization. It has many advantages over the traditional microscope and loupes, which have already been demonstrated in a cadaveric study [7]. An auxiliary, but powerful capability of this system is projection of a second, modifiable image in a split-screen configuration. We hypothesized that integration of both Medtronic and Synaptive platforms could permit the visualization of reconstructed navigation and surgical field images simultaneously. By utilizing navigated instruments, this configuration has the ability to support live image-guided surgery or real-time navigation (RTN). Medtronic O-arm/Stealth S7 navigation, MetRx, NavLock, and SureTrak spinal systems were implemented on a prone cadaveric specimen with a stream output to the Synaptive Display. Surgical visualization was provided using a Storz Image S1 platform and camera mounted to the Synaptive robotic brightmatter drive. We were able to successfully technically co-adapt both platforms. A minimally invasive transforaminal lumbar interbody fusion (MIS TLIF) and an open pedicle subtraction osteotomy (PSO) were performed using a navigated high-speed drill under RTN. Disc Shaver and Trials under RTN were implemented on the MIS TLIF. The synergy of Synaptive HD videoexoscope robotic drive and Medtronic Stealth platforms allow for live image-guided surgery or real-time navigation (RTN). Off-axis projection also allows upright neutral cervical spine operative ergonomics for the surgeons and improved surgical team visualization and education compared to traditional means. This technique has the potential to augment existing minimally invasive and open approaches, but will require long-term outcome measurements for efficacy.

Accuracy of the Enlite 6-day glucose sensor with guardian and Veo calibration algorithms.

PubMed

Keenan, Desmond Barry; Mastrototaro, John Joseph; Zisser, Howard; Cooper, Kenneth A; Raghavendhar, Gautham; Lee, Scott W; Yusi, Jonathan; Bailey, Timothy S; Brazg, Ronald Leonard; Shah, Rajiv V

2012-03-01

This study investigates the accuracy of a newly developed, next-generation subcutaneous glucose sensor, evaluated for 6-day use. Seventy-nine subjects (53 men, 26 women) with type 1 diabetes and 18 subjects (14 men, four women) with type 2 diabetes completed a three-center, prospective, sensor accuracy study. The mean age for the group was 42.2±15.0 years (mean±SD), ranging from 18 to 71 years, with a mean glycosylated hemoglobin level of 7.6±1.5%, ranging from 5.5% to 14%. Subjects wore Enlite™ sensors (Medtronic Diabetes, Northridge, CA) in the abdominal and buttocks region for two separate 7-day periods and calibrated with a home-use blood glucose meter. Subjects participated in an in-clinic testing day where frequent sampled plasma glucose samples were acquired every 15 min for 10 h. Sensor data was retrospectively processed with Guardian(®) REAL-Time (Medtronic) and Paradigm(®) Veo™ (Medtronic) calibration routines, and accuracy metrics were calculated for each algorithm and sensor location. Physiological time lag for each measurement site was calculated. Based on 6,404 plasma-sensor glucose paired points, the Enlite sensor with Veo calibration algorithm produced a mean absolute relative difference of 13.86% with 97.3% of points within the A+B zones of the Clarke error grid. Threshold-only alarms detected 90.1% of hypoglycemia and 90% of hyperglycemia. Mean time lag measured at the abdominal region was 7.94±6.48 min compared with 11.70±6.71 min (P<0.0001) at the buttocks area. The Enlite sensor accurately measures glucose when compared with gold standard laboratory measurements over its 6-day use. Sensors placed in the buttocks region exhibited greater time lags than sensors placed in the abdomen.

76 FR 47210 - Medical Devices; Availability of Safety and Effectiveness Summaries for Premarket Approval...

Federal Register 2010, 2011, 2012, 2013, 2014

2011-08-04

.......... Medtronic Vascular.... Valiant thoracic stent graft April 1, 2011. system. H100002 FDA-2011-M-0241... Scientific Corp ION paclitaxel-eluting coronary April 22, 2011. stent system (monorail and over- the-wire..., 2011. toric IOL. P040012 (S34) FDA-2011-M-0343. Abbott Vascular, Inc.. RX Acculink carotid stent system...

75 FR 7282 - Circulatory System Devices Panel of the Medical Devices Advisory Committee; Notice of Meeting

Federal Register 2010, 2011, 2012, 2013, 2014

2010-02-18

... March 19, 2010, the committee will discuss, make recommendations and vote on a PMA for the REVO MRI Pacemaker System sponsored by Medtronic. The REVO MRI Pacing System is a pacemaker (with a standard pacing indication) that has been specifically designed to be safe for the MRI environment under certain MR scanning...

Sacral neuromodulation and cardiac pacemakers.

PubMed

Roth, Ted M

2010-08-01

Potential for cross-talk between cardiac pacemakers and sacral neuromodulation remains speculative. We present a case series of patients with cardiac pacemakers who underwent staged Interstim (Medtronic, Minneapolis, MN) implantation and patients who had pulse generator implantation who later required cardiac pacemakers. No cross-talk was demonstrated in either group. Sacral neuromodulation appears to be safe in the setting of cardiac pacemakers without cardioversion/defibrillation technology.

Electromagnetic image-guided orbital decompression: technique, principles, and preliminary experience with 6 consecutive cases.

PubMed

Servat, Juan J; Elia, Maxwell Dominic; Gong, Dan; Manes, R Peter; Black, Evan H; Levin, Flora

2014-12-01

To assess the feasibility of routine use of electromagnetic image guidance systems in orbital decompression. Six consecutive patients underwent stereotactic-guided three wall orbital decompression using the novel Fusion ENT Navigation System (Medtronic), a portable and expandable electromagnetic guidance system with multi-instrument tracking capabilities. The system consists of the Medtronic LandmarX System software-enabled computer station, signal generator, field-generating magnet, head-mounted marker coil, and surgical tracking instruments. In preparation for use of the LandmarX/Fusion protocol, all patients underwent preoperative non-contrast CT scan from the superior aspect of the frontal sinuses to the inferior aspect of the maxillary sinuses that includes the nasal tip. The Fusion ENT Navigation System (Medtronic™) was used in 6 patients undergoing maximal 3-wall orbital decompression for Graves' orbitopthy after a minimum of six months of disease inactivity. Preoperative Hertel exophthalmometry measured more than 27 mm in all patients. The navigation system proved to be no more difficult technically than the traditional orbital decompression approach. Electromagnetic image guidance is a stereotactic surgical navigation system that provides additional intraoperative flexibility in orbital surgery. Electromagnetic image-guidance offers the ability to perform more aggressive orbital decompressions with reduced risk.

Pannus Formation Leads to Valve Malfunction in the Tricuspid Position 19 Years after Triple Valve Replacement.

PubMed

Alskaf, Ebraham; McConkey, Hannah; Laskar, Nabila; Kardos, Attila

2016-06-20

The Medtronic ATS Open Pivot mechanical valve has been successfully used in heart valve surgery for more than two decades. We present the case of a patient who, 19 years following a tricuspid valve replacement with an ATS prosthesis as part of a triple valve operation following infective endocarditis, developed severe tricuspid regurgitation due to pannus formation.

Programmable shunt valve interactions with osseointegrated hearing devices.

PubMed

Pierson, Matthew J; Wehrmann, Daniel; Albers, J Andrew; El Tecle, Najib E; Costa, Dary; Elbabaa, Samer K

2017-04-01

OBJECTIVE Patients with ventriculoperitoneal (VP) shunts with programmable valves who would benefit from osseointegrated hearing devices (OIHDs) represent a unique population. The aim of this study was to evaluate the magnetic field strengths of 4 OIHDs and their interactions with 5 programmable VP shunt valves. METHODS Magnetic field strength was measured as a function of distance for each hearing device (Cochlear Baha 5, Cochlear Baha BP110, Oticon Ponto Plus Power, and Medtronic Sophono) in the following modes: inactive, active in quiet, and active in 60 decibels of background noise in the sound booth. The hearing devices were introduced to each shunt valve (Aesculap proGAV, Aesculap proGAV 2.0, Codman Hakim, Codman Certas, and Medtronic Strata II) also as a function of distance in these identical 3 settings. Each trial was repeated 5 times. Between each trial, the valves were assessed for a change in setting. Finally, using a skull model, the devices were introduced to each other in standard anatomical locations and the valves were assessed for a change in settings. RESULTS The maximum magnetic field strengths generated by the Cochlear Baha 5, BP110, and Oticon OIHDs were 1.1, 36.2, and 48.7 gauss (G), respectively. The maximum strength generated by the Sophono device was > 800 G. The magnetic field strength of the hearing devices decreased markedly with increasing distance from the device. The strength of the Sophono's magnetic attachment decreased to 34.8 G at 5 mm. The Codman Hakim, Codman Certas, and Medtronic Strata II valve settings changed when rotating the valves next to the Sophono abutment. No other changes in valve settings occurred in the distance or anatomical models for any other trials. CONCLUSIONS This is the first study evaluating the interaction between OIHDs and programmable VP shunt valves. The findings suggest that it is safe to use these devices together without having to switch to a nonprogrammable valve or move the shunt valve to a more distant location. Still, care should be taken if the Sophono device is used to ensure that the valve is ≥ 5 mm away from the magnetic attachment.

Transcatheter Aortic Valve Implantation: Experience with the CoreValve Device.

PubMed

Asgar, Anita W; Bonan, Raoul

2012-01-01

The field of transcatheter aortic valve implantation has been rapidly evolving. The Medtronic CoreValve first emerged on the landscape in 2004 with initial first human studies, and it is currently being studied in the Pivotal US trial. This article details the current experience with the self-expanding aortic valve with a focus on clinical results and ongoing challenges. Copyright © 2012 Elsevier Inc. All rights reserved.

Rapid and Minimally Traumatic Replacement of Stimulator Extension Cables: Technical Note on a Novel Use for Sternal Wire.

PubMed

Henderson, Fraser; Takacs, Istvan

2017-01-01

Troubleshooting of deep brain stimulators (DBSs, Activa SC/PC/RC Medtronic PLC, Minneapolis, Minnesota, USA) sometimes results in a decision to replace a tunneled stretch-coil extension cable. We present a simple technique to accomplish this atraumatically without a tunneling tool. In the treatment of patients with a DBS, complication avoidance and efficiency of operative time are paramount. We sought to find the safest, most effective, and fastest method of performing the conceptually simple yet technically nuanced act of replacing lead extension cables. We connected #6 (8.0 metric) surgical steel 18″ (45-cm) monofilament (Ethicon US, LLC, Somerville, New Jersey, USA), also known as #6 sternal wire, in line with DBS extension cables (Medtronic DBS Extension 37086-60) in novel fashion to overcome intraprocedural hurdles encountered during the past decade in a busy functional neurosurgery service. Patients tolerate the procedure well and return home shortly after recovery with no complications. A less expensive and faster technique for passing pulse generator extension cables may be the use of a sternal wire. Using the described technique, pulse generators may be quickly and safely adjusted from side to side and site to site as the clinical situation dictates. Copyright © 2016 Elsevier Inc. All rights reserved.

An Alternative Approach for Treating a Type Ia Endoleak after Conventional EVAR Using the Nellix Endovascular Aneurysm Sealing.

PubMed

Martinelli, Ombretta; Fresilli, Mauro; Irace, Luigi; Venosi, Salvatore; Jabbour, Jihad; Picone, Veronica; Maruca, Debora; Di Girolamo, Alessia; Gossetti, Bruno

2018-05-01

To report the use of a Nellix endovascular aneurysm sealing (EVAS) device, to successfully treat a type Ia endoleak (EL) after an endovascular aortic repair (EVAR). A 70-year-old man was diagnosed with a 90-mm aortic aneurysm, suspicious for being inflammatory. It was initially treated successfully, with a Medtronic Endurant (Medtronic, Minneapolis, MN, USA). Five years after the index endovascular repair, an asymptomatic type Ia EL was detected on duplex ultrasound and computed tomographic angiogram. Other endovascular solutions in the form of proximal cuff, chimney was considered difficult to execute due to challenges in planning, manipulation, and renal cannulation caused by the short proximal sealing zone above the existing stent graft and the constraints of the previous endograft. Thus, a relining of the previous endoprothesis was performed using the Nellix system (Endologix, Inc., Irvine, CA, USA). One-year follow-up imaging demonstrated successful resolution of the EL and persistent sealing of the Nellix device. Nellix EVAS system can be an alternative and safe option for relining a stent graft with a type Ia EL. Nellix platform can be added to the clinician's armamentarium for treating type Ia EL after conventional EVAR of infrarenal abdominal aortic aneurysm (AAA). Copyright © 2018 Elsevier Inc. All rights reserved.

Implantation of active fixation leads in coronary veins for left ventricular stimulation: report of five cases.

PubMed

Hansky, Bert; Vogt, Juergen; Gueldner, Holger; Schulte-Eistrup, Sebastian; Lamp, Barbara; Heintze, Johannes; Horstkotte, Dieter; Koerfer, Reiner

2007-01-01

Securing transvenous left ventricular (LV) pacing leads without an active fixation mechanism in proximal coronary vein (CV) segments is usually challenging and frequently impossible. We investigated how active fixation leads can be safely implanted in this location, how to avoid perforating the free wall of the CV, and how to recognize and respond to perforations. In five patients with no alternative to LV pacing from proximal CV segments, 4 Fr SelectSecure (Medtronic, Minneapolis, MN, USA) leads, which have a fixed helix, were implanted through a modified 6 Fr guide catheter with a pre-shaped tip (Launcher, Medtronic). Active fixation leads were successfully implanted in proximal CVs in five patients. There were no complications. Acute and chronic pacing thresholds were comparable to those of conventional CV leads. The pre-shaped guide catheter tip remains in close proximity to the myocardial aspect of the CV, directing the lead helix toward a safe implantation site. If only proximal CV pacing sites are available, 4 Fr SelectSecure leads can be safely implanted through a modified Launcher guide catheter, avoiding more invasive implantation techniques. Other than venous stenting or implantation of leads with retractable tines, SelectSecure leads are expected to remain extractable.

Battery Longevity Comparison of Two Commonly Available Dual Channel Implantable Pulse Generators Used for Subthalamic Nucleus Stimulation in Parkinson's Disease.

PubMed

Fisher, Benjamin; Kausar, Jamilla; Garratt, Hayley; Hodson, James; White, Anwen; Ughratdar, Ismail; Mitchell, Rosalind

2018-06-19

Deep brain stimulation for Parkinson's disease (PD) utilises an implantable pulse generator (IPG) whose finite lifespan in non-rechargeable systems necessitates their periodic replacement. We wish to determine if there is any significant difference in longevity of 2 commonly used IPG systems; the Medtronic Kinetra, and the Medtronic Activa Primary Cell (PC), which has come to replace it. All patients with bilateral Subthalamic Nucleus stimulators for PD performed in our centre were included. Battery life was then assessed using a Kaplan-Meier approach and comparisons between the Kinetra and Activa PC batteries were performed using log-rank tests. Complete data was available for 183 patients. There was a significant difference in the average battery duration with an estimated median battery life in the Kinetra cohort of 6.6 years (95% CI 6.4-6.7), compared to 4.5 years (95% CI 4.4-4.5) in the Activa PC cohort (p < 0.001). The Activa PC IPG demonstrates a significantly reduced battery life of 2.1 years, with a median battery life of 4.5 years in comparison to 6.6 years in the Kinetra IPG. Future technology developments should therefore be focused on improving the battery life of the newer IPG systems. © 2018 S. Karger AG, Basel.

Electrode contact configuration and energy consumption in spinal cord stimulation.

PubMed

de Vos, Cecile C; Hilgerink, Marjolein P; Buschman, Hendrik P J; Holsheimer, Jan

2009-12-01

To test the hypothesis that in spinal cord stimulation, an increase in the number of cathodes increases the energy per pulse, contrary to an increase in the number of anodes, which decreases energy consumption per pulse. Patients with an Itrel III (7425; Medtronic, Inc., Minneapolis, MN) implantable pulse generator and a Pisces-Quad (3487A; Medtronic, Inc.) implantable quadripolar lead were selected for this study. A set of 7 standard contact configurations was used for each patient. Resistor network models mimicking these configurations were constructed. The University of Twente's Spinal Cord Stimulation software was used to simulate the effect of these contact configurations on large spinal nerve fibers. To allow a comparison of the measured and modeled energy per pulse, all values were normalized. Both the empirical and the modeling results showed an increase in energy consumption with an increasing number of cathodes. Although the patient data with 1 and 2 cathodes did not differ significantly, energy consumption was significantly higher when 3 cathodes were used instead of 1 or 2 cathodes. The average energy consumption was significantly higher when bipolar stimulation was used instead of monopolar cathodal stimulation. An increasing number of anodes caused a decrease in energy consumption. When the paresthesia area can be covered with several configurations, it will be beneficial for the patient to program a configuration with 1 cathode and either no or multiple anodes.

Space Maintenance and New Bone Formation with Polyurethane Biocomposites in a Canine Saddle Defect

DTIC Science & Technology

2014-05-01

Vanderbilt University, Nashville, TN 2. Medtronic Spinal and Biologics, Memphis, TN 3. US Army Institute of Surgical Research, Fort Sam Houston, TX...and 15% hydroxyapatite (HA) that is similar in mineral content to natural bone.3 45S5 Bioactive glass (BG) is a resorbable material that has been... used effectively in a variety of bone regeneration applications.4 In the present study, we investigated the ability of injectable PUR/MG and PUR/BG

Finite difference time domain (FDTD) modeling of implanted deep brain stimulation electrodes and brain tissue.

PubMed

Gabran, S R I; Saad, J H; Salama, M M A; Mansour, R R

2009-01-01

This paper demonstrates the electromagnetic modeling and simulation of an implanted Medtronic deep brain stimulation (DBS) electrode using finite difference time domain (FDTD). The model is developed using Empire XCcel and represents the electrode surrounded with brain tissue assuming homogenous and isotropic medium. The model is created to study the parameters influencing the electric field distribution within the tissue in order to provide reference and benchmarking data for DBS and intra-cortical electrode development.

Insulin Pump Malfunction During Hospitalization: Two Case Reports.

PubMed

Faulds, Eileen R; Wyne, Kathleen L; Buschur, Elizabeth O; McDaniel, Jodi; Dungan, Kathleen

2016-06-01

Insulin pump malfunctions and failures continue to occur; however, more severe malfunctions such as the "runaway pump" phenomenon are rarely reported. This article describes two cases of pump malfunction in which pump users appear to have received an unsolicited bolus of insulin resulting in severe episodes of hypoglycemia during hospitalization. Both cases of insulin pump malfunction occurred in the inpatient setting at a large academic medical center in the United States. An analysis of the corresponding insulin pump downloads was performed. The Food and Drug Administration's (FDA's) Manufacturer and User Facility Device Experience (MAUDE) database was searched for similar cases involving Medtronic (Northridge, CA) insulin pumps using the terms "pump," "infusion," "insulin AND malfunction AND Medtronic." The two cases described show remarkable similarities, each demonstrating a severe hypoglycemic event preceded by an infusion site change followed by an alarm. In both cases a rapid spraying of insulin was reported. The insulin pump downloads validated much of the patients' and medical staff's descriptions of events. The FDA's MAUDE database search revealed 425 cases meeting our search term criteria. All cases were reviewed. Seven cases were identified involving independent movement of the reservoir piston. The cases detailed are the first to describe an insulin pump malfunction of this nature in the hospital setting involving unsolicited insulin boluses leading to severe hypoglycemia. The cases are particularly compelling in that they were witnessed by medical personnel. Providers and patients should receive instruction education on the recognition and management of insulin pump malfunction.

The safety of magnetic resonance imaging in patients with programmable implanted intrathecal drug delivery systems: a 3-year prospective study.

PubMed

De Andres, Jose; Villanueva, Vicente; Palmisani, Stefano; Cerda-Olmedo, German; Lopez-Alarcon, Maria Dolores; Monsalve, Vicente; Minguez, Ana; Martinez-Sanjuan, Vicente

2011-05-01

It is common clinical practice to perform magnetic resonance imaging (MRI) in patients with indwelling programmable intrathecal drug delivery (IDD) systems, although the safety of the procedure has never been documented. We performed a single-center, 3-year, prospective evaluation in patients with a programmable implanted IDD to assess patient discomfort, IDD technical failures, and adverse effects during and after exposure to MRI. Forty-three consecutive patients with an implanted programmable IDD system (SynchroMed® EL Implantable Infusion Pump, Model 8626L-18, and SynchroMed® II Model 8637-20, 8637-40; Medtronic, Inc., Minneapolis, MN) requiring a scheduled MRI evaluation were studied during a 3-year period. All MRI scans were performed with a 1.5-tesla clinical use magnet and a specific absorption rate of no more than 0.9 W/kg. Radiograph control was used to confirm postexposure pump rotor movement and detect system dislocations. IDD system failures, patient satisfaction, and discomfort were recorded. None of the patients experienced signs of drug overinfusion that could lead to hemodynamic, respiratory, or neurologic alterations. Radiologic evaluation after MRI revealed no spatial displacements of the intrathecal catheter tip or body pump, and programmer telemetry confirmed the infusion recovery. Patients' satisfaction after the procedure was high. Performing an MRI scan with the proposed protocol in patients with an implanted Medtronic programmable IDD system resulted in virtually no technical or medical complications. © 2011 International Anesthesia Research Society

Glycaemic index of selected foodstuffs in healthy persons.

PubMed

Fajkusova, Zuzana; Jadviscokova, Tereza; Pallayova, Maria; Matuskova, Veronika; Luza, Jiri; Kuzmina, Galina

2007-12-01

The aim of this study was to determine glycaemic index (GI) of 10 popular foodstuffs/mixed meals in healthy persons. Ten tested foodstuffs and glucose standard were consumed in three replicates in the course of a defined 9-day meal plan: puffed rice squares with chocolate, dark chocolate, white bread, honey and glucose for breakfast (at 7 a.m.) and dinner (at 8 p.m.); pasta with meat, fried fish with mashed potatoes, and buttered apricot dumplings for lunch (at 12 a.m.); wafers, puffed spelt squares with chocolate, and tomato soup for snack (at 4 p.m.). Each portion contained 50 g of carbohydrates and was consumed within 30 minutes. Glucose concentrations were measured by means of the Continous Glucose Monitoring System (CGMS, Medtronic Minimed, Northridge, CA, USA). The results were processed by Solutions Software (Medtronic Minimed, Northridge, CA, USA) and DegifXL4 software, Palacký University, Olomouc, CZ. Twenty healthy persons aged 21.9 +/- 1.39 y (mean +/- SE), BMI 23.6 +/- 0.63 kg/m(2) completed the study. GI of tested foodstuffs ranged from 34.7 % (chocolate) to 105.3 % (puffed rice squares with chocolate). There were more than tenfold differences between minimal and maximal values of the GI for some foodstuffs. Significant interindividual differences were found between GIs of foodstuffs. In twenty healthy persons the glycaemic indexes of ten popular foodstuffs were determined, to be added to the nutritional labels in order to facilitate the optimum meal planning.

Occurence of adverse events due to continuous glucose monitoring.

PubMed

Jadviscokova, Tereza; Fajkusova, Zuzana; Pallayova, Maria; Luza, Jiri; Kuzmina, Galina

2007-12-01

Continuous glucose monitoring (CGM) using transcutaneous sensors is becoming a sophisticated method to control and regulate glucose metabolism. The transcutaneous sensor of the CGM system (CGMS Medtronic Minimed, Northridge, CA, USA) is chosen to measure glucose concentration in interstitial fluid up to three days after insertion even though its function remains stable for a longer period. The question arises, which factors really limit the period of sensor insertion without unnecessary risk. The aim of this study was to assess any adverse events occurring in the course of 9 days after the sensor insertion. In a group of 22 healthy volunteers aged 21.8+/-1.30 y (mean +/- SE) a total of 26 sensors was inserted subcutaneously in gluteal or lumbar region for 9 days. Before insertion the site was sprayed with an antiseptic (Cutasept F, Bode Chemie, Hamburg, Germany). Local adverse reactions and disturbances in general condition were examined. In the course of 184 sensor-days, there were only minor local adverse events: hypersensitivity, itching, pain, redness, burning, subcutaneous hemorrhage. Additionally, sleep disturbances, attention deficits, problems related to the CGMS monitor, to adhesive tape and/or sensor were found. None of these resulted in sensor withdrawal. In 12 volunteers (55 %) no complications were observed. The sensor function measured according to electrical signals (ISIG) failed (always on day 1-2) in 4 cases (16 %). The present FDA approved 3-day insertion period for Medtronic transcutaneous sensor does not seem to limit its use and appears to be worth a careful revision.

Modeling the Error of the Medtronic Paradigm Veo Enlite Glucose Sensor.

PubMed

Biagi, Lyvia; Ramkissoon, Charrise M; Facchinetti, Andrea; Leal, Yenny; Vehi, Josep

2017-06-12

Continuous glucose monitors (CGMs) are prone to inaccuracy due to time lags, sensor drift, calibration errors, and measurement noise. The aim of this study is to derive the model of the error of the second generation Medtronic Paradigm Veo Enlite (ENL) sensor and compare it with the Dexcom SEVEN PLUS (7P), G4 PLATINUM (G4P), and advanced G4 for Artificial Pancreas studies (G4AP) systems. An enhanced methodology to a previously employed technique was utilized to dissect the sensor error into several components. The dataset used included 37 inpatient sessions in 10 subjects with type 1 diabetes (T1D), in which CGMs were worn in parallel and blood glucose (BG) samples were analyzed every 15 ± 5 min Calibration error and sensor drift of the ENL sensor was best described by a linear relationship related to the gain and offset. The mean time lag estimated by the model is 9.4 ± 6.5 min. The overall average mean absolute relative difference (MARD) of the ENL sensor was 11.68 ± 5.07% Calibration error had the highest contribution to total error in the ENL sensor. This was also reported in the 7P, G4P, and G4AP. The model of the ENL sensor error will be useful to test the in silico performance of CGM-based applications, i.e., the artificial pancreas, employing this kind of sensor.

Successful use of a left ventricular apical access and closure device for second-generation transapical aortic valve implantation.

PubMed

Conradi, Lenard; Seiffert, Moritz; Shimamura, Kazuo; Schirmer, Johannes; Blankenberg, Stefan; Reichenspurner, Hermann; Diemert, Patrick; Treede, Hendrik

2014-09-01

Transcatheter aortic valve implantation (TAVI) has become routine for the treatment of high-risk patients with aortic stenosis. We assessed safety and feasibility of a left ventricular apical access and closure device combined with second-generation transapical (TA) TAVI transcatheter heart valves (THV). Three elderly, comorbid patients (logEuroSCORE I 13.0-31.1%) received transapical aortic valve implantation (TA-AVI) via the Apica ASC device (Apica Cardiovascular Ltd., Galway, Ireland) using second-generation THV (Medtronic Engager [Medtronic 3F Therapeutics, Santa Ana, California, United States], JenaValve [JenaValve Technology GmbH, Munich, Germany], Symetis Acurate [Symetis S.A., Ecublens, Switzerland]). Access was gained using a non-rib-spreading technique and a novel access and closure device. THV deployment was successful with excellent hemodynamic outcome (no PVL, n = 2; trace PVL, n = 1; mean transvalvular gradients, 5-19 mm Hg) and complete apical hemostasis. No periprocedural major adverse events occurred and Valve Academic Research Consortium-2-defined composite end point of device success was met in all cases. Safety and feasibility of TA-AVI using the ASC device with second-generation THV was demonstrated. Combining latest available technology is a major step toward improved functional outcome and decreased surgical trauma in TA-AVI. Potentially, technical enhancements may eventually pave the way toward a fully percutaneous TA-AVI procedure. Georg Thieme Verlag KG Stuttgart · New York.

The use of carbon dioxide angiography for renal sympathetic denervation: a technical report.

PubMed

Renton, Mary; Hameed, Mohammad A; Dasgupta, Indranil; Hoey, Edward T D; Freedman, Jonathan; Ganeshan, Arul

2016-12-01

Hypertension is the leading attributable cause of cardiovascular mortality worldwide. Patients with hypertension have multiple comorbidities including high rates of concomitant renal disease. Current pharmacological approaches are inadequate in the treatment of resistant hypertension. Renal sympathetic denervation (RDN) has been shown to effectively treat resistant hypertension. The traditional use of iodinated contrast in RDN is contraindicated in patients with significant renal insufficiency. In patients with renal impairment, carbon dioxide (CO 2 ) can be used as an alternative contrast material for RDN. This article describes the technical aspects of RDN using CO 2 angiography. Our centre is experienced in the innovative RDN procedure using CO 2 angiography. We describe the protocol for CO 2 angiography for RDN using a home-made CO 2 delivery system and the Symplicity ™ (Minneapolis MN 55432 USA) catheter (Medtronic) device. CO 2 angiography is an excellent alternative to iodinated contrast for RDN procedures. CO 2 angiography for RDN is a safe and effective alternative to iodinated contrast. RDN using CO 2 angiography is an easy and feasible procedure that can be used in patients with renal insufficiency or iodinated contrast allergies. Advances in knowledge: There is a paucity of descriptive reports for CO 2 angiography for RDN and we provide details of the optimal protocol for the procedure. In particular, we describe the use of a Symplicity Spyral ™ catheter (Medtronic), which has not been reported to date for use in this procedure.

Pacing-induced chronic atrial fibrillation impairs sinus node function in dogs. Electrophysiological remodeling.

PubMed

Elvan, A; Wylie, K; Zipes, D P

1996-12-01

We assessed the effects of pacing-induced chronic atrial fibrillation (AF) on sinus node function, intra-atrial conduction, and atrial refractoriness. In 15 mongrel dogs (20 to 30 kg), AV nodal block was produced by radiofrequency catheter ablation, and a ventricular-inhibited (VVI) pacemaker (Minix 8330, Medtronic) was implanted and programmed to pace at 80 pulses per minute. In 11 of these dogs, right atrial endocardial pacing leads were connected to a pulse generator (Itrel 7432, Medtronic) and set at a rate of 20 Hz to induce AF. Corrected sinus node recovery time, P-wave duration, 24-hour Holter ECG to assess AF duration, maximal heart rate in response to isoproterenol (10 micrograms/min), intrinsic heart rate after administration of atropine (0.04 mg/kg) and propranolol (0.1 mg/kg), and atrial effective refractory periods (ERPs) were obtained at baseline (EPS-1) and after 2 to 6 weeks (EPS-2) of VVI pacing alone (n = 4) or VVI pacing and rapid atrial pacing (n = 11). At EPS-2, corrected sinus node recovery time and P-wave duration were prolonged, maximal heart rate and intrinsic heart rate were decreased, atrial ERPs were shortened, and the duration of AF was increased significantly compared with EPS-1. These changes partially reversed toward baseline 1 week after conversion to sinus rhythm. Sinus node function and AF inducibility observed in the control dogs that underwent ventricular pacing alone (n = 4) did not change. Pacing-induced chronic AF induces sinus node dysfunction, prolongs intra-atrial conduction time, shortens atrial refractoriness, and perpetuates AF, changes that reverse gradually after termination of AF.

Comparative study about the tensile strength and yielding mechanism of pacing lead among major manufacturers.

PubMed

Chi-Wo, Chan; Lip-Kiong, Chan; Tongny, Lam; Kin-Keung, Tsang; Kin-Wing, Chan

2018-05-14

With extraction of cardiovascular implantable electronic devices (CIED) increasingly necessitated, various studies have contemplated to investigate clinical predictors for its success and complications. Intrinsic parameters of CIED leads have been studied less extensively and are the foci of this study. Three major pacemaker manufacturers accepted invitation. Leads then underwent tensile test in-vitro with their composite tensile strength (TS) compared. Mechanism of yielding, under tensile stress, was also observed among them. All pacing leads, participated in this study, surpassed requirement of European Standard EN 45502-2-1. Boston Scientific's FINELINE II STENOX 4456/52 cm and Medtronic's CAPSURE SENSE 4074/52 cm showed similar composite TS and both were stronger compared with St. Jude Medical's ISOFLEX OPTIM 1948/52 cm (P < 0.001). Despite a difference in the exact site, the Medtronic 4074 and St. Jude Medical 1948 yielded similarly in that their distal tip electrode remained connected with a flimsy inner coil to proximal portion of the lead after their composite TS was exceeded. Boston Scientific 4456's insulation tubing and coil wire broke almost simultaneously and separated completely from the tip electrode when it yielded. FINELINE II STENOX 4456/52 cm and CAPSURE SENSE 4074/52 cm showed stronger composite tensile strength than ISOFLEX OPTIM 1948/52 cm. FINELINE II STENOX 4456 was found more prone to complete severance. Limitations and precautions to translate these differences directly into real-life scenario are discussed. This article is protected by copyright. All rights reserved. This article is protected by copyright. All rights reserved.

In vitro evaluation of the Medtronic cardioplegia safety system.

PubMed

Trowbridge, C C; Woods, K R; Muhle, M L; Niimi, K S; Tremain, K D; Jiang, J; Stammers, A H

2000-03-01

Myocardial preservation demands the precise and accurate delivery of cardioplegic solutions to provide nutritive delivery and metabolic waste removal. The purpose of this study was to evaluate the performance characteristics of the Medtronic CSS Cardioplegia Safety System in an in vitro setting. The CSS was evaluated under the following conditions: blood to crystalloid ratios of 1:0, 1:1, 4:1, 8:1, 0:1; potassium concentrations of 10, 20, and 40 mEq L-1; volumetric delivery collection at 100, 250, 500, 750, and 990 mL/min; pressure accuracy at 100 and 300 mmHg; and system safety mechanisms. Measured and predicted values from the CSS were compared using one way ANOVA, with statistical significance accepted at p < or = 0.05. The measured values for the tested ratios and volume collections were all within the manufacturer's technical parameters. Potassium concentration results were all within expected values except at 100 mL/min, where the measured value of 17.1 +/- 2.1 mmol was lower than the expected 20.0 +/- 0.2 mmol (p < .034). As flow rates changed, the CSS line pressure error was constant (0.5 to 3.7%), and the only significant difference was observed at 100 mmHg, 500 mL/min (102.3 +/- 1.7 vs. 100.0 +/- 0.0 mmHg, P < .003). The device performed accurately and reliably under all simulated safety conditions, including bubble detection, over pressurization and battery backup. In conclusion, the performance of the CSS was within the manufacturer's specifications for the majority of the tested conditions and operated safely when challenged under varying conditions.

Guide to preemption of state-law claims against Class III PMA medical devices.

PubMed

Whitney, Daniel W

2010-01-01

There is a perception that the express preemption holding of the Supreme Court in Riegel v. Medtronic, 552 U.S. 312(2008), immunizes medical device manufacturers from common law personal injury actions involving Class III devices that received FDA clearance under a premarket approval application (PMA). In the aftermath of Riegel, many lawsuits involving Class III PMA devices have been dismissed by district courts applying the new heightened pleading standard of Bell Atlantic Corp. v. Twombly, 550 U.S. 544 (2007). Other lawsuits involving Class III PMA devices premised on fraud-on-FDA have been dismissed based on the implied preemption holding of the Supreme Court in Buckman v. Plaintiffs' Legal Comm., 531 U.S. 341 (2001). When these decisions are carefully analyzed together with Medtronic, Inc. v. Lohr, 518 U.S. 470 (1996), which found no preemption regarding a Class III device receiving FDA clearance through the 510(k) mechanism, it is apparent that the preemption defense does not apply universally to Class III PMA devices. The overall methodology for framing a non-preempted claim is to first identify conduct which violated the PMA or other specific requirements related to safety or efficacy. If such conduct can also be stated in terms of a breach of a parallel common law duty (e.g, failure to warn under strict liability or negligence, manufacturing defect or breach of warranty), then it would appear the claim is not preempted. Alternatively, regardless of a specific violation, common law remedies are not preempted by general CGMP requirements.

Siphon effects on continuous subcutaneous insulin infusion pump delivery performance.

PubMed

Zisser, Howard C; Bevier, Wendy; Dassau, Eyal; Jovanovic, Lois

2010-01-01

The objective was to quantify hydrostatic effects on continuous subcutaneous insulin infusion (CSII) pumps during basal and bolus insulin delivery. We tested CSII pumps from Medtronic Diabetes (MiniMed 512 and 515), Smiths Medical (Deltec Cozmo 1700), and Insulet (OmniPod) using insulin aspart (Novolog, Novo Nordisk). Pumps were filled and primed per manufacturer's instructions. The fluid level change was measured using an inline graduated glass pipette (100 microl) when the pipette was moved in relation to the pump (80 cm Cosmo and 110 cm Medtronics) and when level. Pumps were compared during 1 and 5 U boluses and basal insulin delivery of 1.0 and 1.5 U/h. Pronounced differences were seen during basal delivery in pumps using 80-100 cm tubing. For the 1 U/h rate, differences ranged from 74.5% of the expected delivery when the pumps were below the pipettes and pumping upward to 123.3% when the pumps were above the pipettes and pumping downward. For the 1.5 U/h rate, differences ranged from 86.7% to 117.0% when the pumps were below or above the pipettes, respectively. Compared to pumps with tubing, OmniPod performed with significantly less variation in insulin delivery. Changing position of a conventional CSII pump in relation to its tubing results in significant changes in insulin delivery. The siphon effect in the tubing may affect the accuracy of insulin delivery, especially during low basal rates. This effect has been reported when syringe pumps were moved in relation to infusion sites but has not been reported with CSII pumps. 2010 Diabetes Technology Society.

Atrial septal pacing in small dogs: a pilot study.

PubMed

Jones, Ashley E; Estrada, Amara H; Pariaut, Romain; Sosa-Samper, Ivan; Shih, Andre C; Mincey, Brandy D; Moïse, N Sydney

2014-09-01

To determine the feasibility of atrial septal pacing via a delivery catheter-guided small non-retracting helix pacing lead. Six healthy beagles (8.3-12.9 kg). Using single plane fluoroscopic guidance, Medtronic(®) 3830 SelectSecure leads were connected to the atrial septum via Medtronic® Attain Select® II standard 90 Left Heart delivery catheter. Pacing threshold and lead impedance were measured at implantation. The Wenckebach point was tested via atrial pacing up to 220 paced pulses per minute (ppm). Thoracic radiographs were performed following implantation to identify the lead position, and repeated at 24 h, 1 month, and 3 months post-operatively. Macro-lead dislodgement occurred in two dogs at 24 h and in three dogs at one-month post-implantation. Lead impedance, measured at the time of implantation, ranged from 583 to 1421 Ω. The Wenckebach point was >220 ppm in four of the six dogs. The remaining two dogs had Wenckebach points of 120 and 190 ppm. This pilot study suggests the selected implantation technique and lead system were inadequate for secure placement in the atrial septum of these dogs. The possible reasons for inadequate stability include unsuitable lead design for this location, inadequate lead slack at the time of implantation and inadequate seating of the lead as evidenced by low impedance at the time of implantation. Other implantation techniques and/or pacing leads should be investigated to determine the optimal way of pacing the atria in small breed dogs that are prone to sinus node dysfunction. Copyright © 2014 Elsevier B.V. All rights reserved.

Proximal protection with hybrid stent, a safer combination for carotid artery stenting against carotid endarterectomy?

PubMed

Gürkaş, E; Ak, F; Orhan, G; Bozkurt, E; Ulusoy, E K

2015-12-01

Carotid revascularization is an established theurapeutic modality in preventing stroke and death among patients with severe carotid stenosis. Although carotid endarterectomy remains as the primary option, carotid stenting is accepted as an alternative for patients with high risk for carotid endarterectomy. Recently published reports have better results with proximal protection devices when compared with distal protection devices. These studies have revealed less microembolic signals and less periprocedural new ischemic lesions on diffusion weighted magnetic resonance imaging. Stent choice may be also important for these procedures as open cell stent design has advantage of better flexibility whereas closed cell systems have an advantage of better scaffolding. Hybrid stents which are composed of open cells in the proximal and distal part and closed cells in the middle may carry both advantages. The aim of this study is to demonstrate whether combination of proximal protection devices with hybrid stents can be a safe alternative for carotid stenting in terms of periprocedural and 30-day outcomes. Here we retrospectively evaluated 68 symptomatic carotid stenosis patients undergoing carotid stenting with hybrid stent (Cristallo Ideale®, Invatec s.r.l., Medtronic, Italy) and proximal protection device (MO.MA®, Invatec s.r.l., Medtronic, Italy). Our results showed only 1 minor stroke in the periprocedural period and during the first 30-day after stenting, with no death or myocardial infarction. Although our case number is not large, we propose that carotid stenting may be safer with utilization of proximal protection system and hybrid type carotid stents.

Runaway pacemaker: a forgotten phenomenon?

PubMed

Ortega, Daniel F; Sammartino, M Victoria; Pellegrino, Graciela M M; Barja, Luis D; Albina, Gaston; Segura, Eliseo V; Balado, Roberto; Laiño, Ruben; Giniger, Alberto G

2005-11-01

Runaway is an uncommon pacemaker dysfunction, characterized by fast and erratic spikes at non-physiological rates. This infrequent but potentially lethal failure mode may be related to low battery voltage. Four single chamber pacemaker patients were analyzed (Medtronic Minix ST 8330, Minneapolis, MN, had been implanted in two patients and two CPI Triumph VR 1124, St Paul, MN, in the other two). They had been admitted because of presyncopal episodes. Typical high rate stimuli at 2000 ppm alternating with pacing at 60-65 ppm were recorded in all ECGs. Lead system tests were normal. The pulse generators had to be replaced.

Retrospective Analysis Comparing Hollow Fiber and Silicone Membrane Oxygenators for Neonates on ECMO

PubMed Central

Mejak, Brian; Giacomuzzi, Carmen; Heller, Eileen; You, Xiaomang; Ungerleider, Ross; Shen, Irving

2007-01-01

Abstract: There is little information showing the use of microporous polypropylene hollow fiber oxygenators during extracorporeal life support (ECLS). Recent surveys have shown increasing use of these hollow fibers amongst ECLS centers in the United States. We performed a retrospective analysis comparing the Terumo BabyRx hollow fiber oxygenator to the Medtronic 800 silicone membrane oxygenator on 14 neonatal patients on extracorporeal membrane oxygenation (ECMO). The aim of this study was to investigate the similarities and differences when comparing pressure drops, prime volumes, oxygenator endurance, and gas transfer capabilities between the two groups. PMID:17672186

The use of a stentless porcine bioprosthesis to repair an ascending aortic aneurysm in combination with aortic valve regurgitation.

PubMed Central

Akpinar, B; Sanisoğlu, I; Konuralp, C; Akay, H; Güden, M; Sönmez, B

1999-01-01

Over the years, many surgical methods have evolved for the treatment of ascending aortic aneurysm in combination with aortic valve regurgitation; however, precise guidelines for optimal surgical techniques for varying presentations have not been defined. We describe the use of a stentless porcine bioprosthesis (Medtronic Freestyle) in a patient with an ascending aortic aneurysm and aortic regurgitation. We used the complete root replacement method, and anastomosed a Dacron graft (Hemashield) between the bioprosthetic valve and the native aorta to replace the distal part of the aneurysm. Images PMID:10524742

Comparison of Two Electromagnetic Navigation Systems For CT-Guided Punctures: A Phantom Study.

PubMed

Putzer, D; Arco, D; Schamberger, B; Schanda, F; Mahlknecht, J; Widmann, G; Schullian, P; Jaschke, W; Bale, R

2016-05-01

We compared the targeting accuracy and reliability of two different electromagnetic navigation systems for manually guided punctures in a phantom. CT data sets of a gelatin filled plexiglass phantom were acquired with 1, 3, and 5 mm slice thickness. After paired-point registration of the phantom, a total of 480 navigated stereotactic needle insertions were performed manually using electromagnetic guidance with two different navigation systems (Medtronic Stealth Station: AxiEM; Philips: PercuNav). A control CT was obtained to measure the target positioning error between the planned and actual needle trajectory. Using the Philips PercuNav, the accomplished Euclidean distances were 4.42 ± 1.33 mm, 4.26 ± 1.32 mm, and 4.46 ± 1.56 mm at a slice thickness of 1, 3, and 5 mm, respectively. The mean lateral positional errors were 3.84 ± 1.59 mm, 3.84 ± 1.43 mm, and 3.81 ± 1.71 mm, respectively. Using the Medtronic Stealth Station AxiEM, the Euclidean distances were 3.86 ± 2.28 mm, 3.74 ± 2.1 mm, and 4.81 ± 2.07 mm at a slice thickness of 1, 3, and 5 mm, respectively. The mean lateral positional errors were 3.29 ± 1.52 mm, 3.16 ± 1.52 mm, and 3.93 ± 1.68 mm, respectively. Both electromagnetic navigation devices showed excellent results regarding puncture accuracy in a phantom model. The Medtronic Stealth Station AxiEM provided more accurate results in comparison to the Philips PercuNav for CT with 3 mm slice thickness. One potential benefit of electromagnetic navigation devices is the absence of visual contact between the instrument and the sensor system. Due to possible interference with metal objects, incorrect position sensing may occur. In contrast to the phantom study, patient movement including respiration has to be compensated for in the clinical setting. • Commercially available electromagnetic navigation systems have the potential to improve the therapeutic range for CT guided percutaneous procedures by comparing the needle placement accuracy on the basis of planning CT data sets with different slice thickness. Citation Format: • Putzer D, Arco D, Schamberger B et al. Comparison of Two Electromagnetic Navigation Systems For CT-Guided Punctures: A Phantom Study. Fortschr Röntgenstr 2016; 188: 470 - 478. © Georg Thieme Verlag KG Stuttgart · New York.

Comparison of two high-resolution manometry software systems in evaluating esophageal motor function.

PubMed

Rengarajan, A; Drapekin, J; Patel, A; Gyawali, C P

2016-12-01

High-resolution manometry (HRM) utilizes software tools to diagnose esophageal motor disorders. Performance of these software metrics could be affected by averaging and by software characteristics of different manufacturers. High-resolution manometry studies on 86 patients referred for antireflux surgery (61.6 ± 1.4 year, 70% F) and 20 healthy controls (27.9 ± 0.7 year, 45% F) were first subject to standard analysis (Medtronic, Duluth, GA, USA). Coordinates for each of 10 test swallows were exported and averaged to generate a composite swallow. The swallows and averaged composites were imported as ASCII file format into Manoview (Medtronic) and Medical Measurement Systems database reporter (MMS, Dover, NH, USA), and analyses repeated. Comparisons were made between standard and composite swallow interpretations. Correlation between the two systems was high for mean distal contractile integral (DCI, r 2 ≥ 0.9) but lower for integrated relaxation pressure (IRP, r 2 = 0.7). Excluding achalasia, six patients with outflow obstruction (mean IRP 23.2 ± 2.1 with 10-swallow average) were identified by both systems. An additional nine patients (10.5%) were identified as outflow obstruction (15 mmHg threshold) with MMS 10-swallow and four with MMS composite swallow evaluation; only one was confirmed. Ineffective esophageal motility was diagnosed by 10-swallow evaluation in 19 (22.1%) with Manoview, and 20 (23.3%) with MMS. On Manoview composite, 17 had DCI <450 mmHg/cm/s, and on MMS composite, 21, (p ≥ 0.85 for each comparison) but these did not impact diagnostic conclusions. Comparison of 10 swallow and composite swallows demonstrate variability in software metrics between manometry systems. Our data support use of manufacturer specific software metrics on 10-swallow sequences. © 2016 John Wiley & Sons Ltd.

Real-world geographic variations in the use of cardiac implantable electronic devices - The PANORAMA 2 observational cohort study.

PubMed

Bastian, Dirk; Ebrahim, Iftikhar O; Chen, Ju-Yi; Chen, Mien-Cheng; Huang, Dejia; Huang, Jin-Long; Kuznetsov, Vadim A; Maus, Bärbel; Naik, Ajay M; Verhees, Koen J P; Fagih, Ahmed R Al

2018-06-13

Currently, several geographies around the world remain underrepresented in medical device trials. The PANORAMA 2 study was designed to assess contemporary region-specific differences in clinical practice patterns of patients with cardiac implantable electronic devices (CIEDs). In this prospective, multicenter, observational, multi-national study, baseline and implant data of 4,706 patients receiving Medtronic CIEDs (either de novo device implants, replacements, or upgrades) were analyzed, consisting of: 54% implantable pulse generators (IPGs), 20.3% implantable cardiac defibrillators (ICDs), 15% cardiac resynchronization therapy defibrillators (CRT-Ds), 5.1% cardiac resynchronization therapy pacemakers (CRT-Ps), from 117 hospitals in 23 countries across 4 geographical regions between 2012 and 2016. For all device types, in all regions, there were less females than males enrolled, and women were less likely to have ischemic cardiomyopathy. Implant procedure duration differed significantly across the geographies for all device types. Subjects from emerging countries, women and older patients were less likely to receive a magnetic resonance imaging (MRI)-compatible device. Defibrillation testing differed significantly between the regions. European patients had the highest rates of atrial fibrillation (AF), and the lowest number of implanted single-chamber IPGs. Evaluation of stroke history suggested that the general embolic risk is more strongly associated with stroke than AF. We provide comprehensive descriptive data on patients receiving Medtronic CIEDs from several geographies, some of which are understudied in randomized controlled trials (RCTs). We found significant variations in patient characteristics. Several medical decisions appear to be affected by socioeconomic factors. Long-term follow-up data will help evaluate if these variations require adjustments to outcome expectations. This article is protected by copyright. All rights reserved. This article is protected by copyright. All rights reserved.

Technician-Supported Remote Interrogation of CIEDs: Initial Use in US Emergency Departments and Perioperative Areas.

PubMed

Ahmed, Imdad; Patel, Amisha S; Balgaard, Timothy J; Rosenfeld, Lynda E

2016-03-01

Interrogation/interpretation of cardiac implantable electronic devices (CIEDs) is frequently required in the emergency department (ED) or perioperative areas (OR) where resources to do this are often not available. CareLink Express (CLE; Medtronic, plc, Mounds View, MN, USA) is a technician-supported real-time remote interrogation system for Medtronic CIEDs. Using data from 136 US locations, this retrospective study was designed to assess CLE efficiency compared to traditional device management, and examine its findings. All 7,044 US CLE transmissions from the ED and OR (January 2012-October 2014) were compared to 217 traditional requests where CIED interrogations/interpretations were performed by calling industry representatives to these sites. CLE reduced the time to device interrogation/interpretation by 78%: 100 ± 140-22 ± 14 minutes, P < 0.0001, improving response time and consistency; ED: 82 ± 103-23 ± 18 minutes, P, ≤ 0.01; OR: 127 ± 181-17 ± 10 minutes, P < 0.0001. Actionable events (AE) (arrhythmia, device/lead abnormalities) were infrequent: 9.1% overall (ED: 9.9%; OR: 4.1%). Only 6.5% of patients with syncope/presyncope and 13.6% with a perceived shock had AE. AEs were more common in those with suspected device problems (30.4%) or audible alerts (52.6%). They were more likely in patients not enrolled in long-term remote monitoring (23.9% vs 8.2%, P < 0.0001) and in those with older CIED systems (7.4% in year 1 vs 31.0% after 10 years). The many patients with CIEDs, and the ability to quickly identify the minority with high-risk AE from the no/low-risk majority, strongly support CLE use in the ED and OR, sites which are expensive and prioritize efficiency. © 2015 Wiley Periodicals, Inc.

Registry of transcatheter aortic-valve implantation in high-risk patients.

PubMed

Gilard, Martine; Eltchaninoff, Hélène; Iung, Bernard; Donzeau-Gouge, Patrick; Chevreul, Karine; Fajadet, Jean; Leprince, Pascal; Leguerrier, Alain; Lievre, Michel; Prat, Alain; Teiger, Emmanuel; Lefevre, Thierry; Himbert, Dominique; Tchetche, Didier; Carrié, Didier; Albat, Bernard; Cribier, Alain; Rioufol, Gilles; Sudre, Arnaud; Blanchard, Didier; Collet, Frederic; Dos Santos, Pierre; Meneveau, Nicolas; Tirouvanziam, Ashok; Caussin, Christophe; Guyon, Philippe; Boschat, Jacques; Le Breton, Herve; Collart, Frederic; Houel, Remi; Delpine, Stephane; Souteyrand, Geraud; Favereau, Xavier; Ohlmann, Patrick; Doisy, Vincent; Grollier, Gilles; Gommeaux, Antoine; Claudel, Jean-Philippe; Bourlon, Francois; Bertrand, Bernard; Van Belle, Eric; Laskar, Marc

2012-05-03

Transcatheter aortic-valve implantation (TAVI) is an emerging intervention for the treatment of high-risk patients with severe aortic stenosis and coexisting illnesses. We report the results of a prospective multicenter study of the French national transcatheter aortic-valve implantation registry, FRANCE 2. All TAVIs performed in France, as listed in the FRANCE 2 registry, were prospectively included in the study. The primary end point was death from any cause. A total of 3195 patients were enrolled between January 2010 and October 2011 at 34 centers. The mean (±SD) age was 82.7±7.2 years; 49% of the patients were women. All patients were highly symptomatic and were at high surgical risk for aortic-valve replacement. Edwards SAPIEN and Medtronic CoreValve devices were implanted in 66.9% and 33.1% of patients, respectively. Approaches were either transarterial (transfemoral, 74.6%; subclavian, 5.8%; and other, 1.8%) or transapical (17.8%). The procedural success rate was 96.9%. Rates of death at 30 days and 1 year were 9.7% and 24.0%, respectively. At 1 year, the incidence of stroke was 4.1%, and the incidence of periprosthetic aortic regurgitation was 64.5%. In a multivariate model, a higher logistic risk score on the European System for Cardiac Operative Risk Evaluation (EuroSCORE), New York Heart Association functional class III or IV symptoms, the use of a transapical TAVI approach, and a higher amount of periprosthetic regurgitation were significantly associated with reduced survival. This prospective registry study reflected real-life TAVI experience in high-risk elderly patients with aortic stenosis, in whom TAVI appeared to be a reasonable option. (Funded by Edwards Lifesciences and Medtronic.).

Validation of criteria for selective his bundle and para-hisian permanent pacing.

PubMed

Cantù, F; De Filippo, P; Cardano, P; De Luca, A; Gavazzi, A

2006-12-01

His Bundle (HB) pacing is a valid alternative to right ventricular pacing for patients with preserved His-ventricle conduction who are candidates for permanent stimulation. Permanent pacing in the HB area enables Selective HB pacing (SHBP) or para-Hisian pacing (PHP) to be achieved. The aim of our study was to draw up a set of easy criteria to differentiate and validate the two kinds of stimulations according to the pacing output and the ECG/EKG signals. From February to July 2005, 17 patients eligible for a pacemaker (PM) procedure underwent implantation with the Medtronic SelectSecure lead (Medtronic, Minneapolis, MN, USA) screwed into the HB area.SHBP was defined when the intrinsic QRS was equal, in both duration and morphology, to the paced QRS, the His-Ventricular (H-V) interval was equal to Pace-Ventricular interval (Vp-V) and, at low output, only the HB was captured, while increasing the output resulted in both the HB and right ventricular (RV) being captured (widening of QRS at high output). Conversely, PHP was defined when the intrinsic QRS differed from the paced one, either in morphology or in duration and, at high output, both the RV and HB were captured (non-SHBP), while decreasing the output resulted in losing HB capture (widening of QRS at low output). According to these criteria, SHBP was achieved in 11 patients, while in the remaining 6, PHP was obtained. No adverse events were reported. The above criteria enabled SHBP and PHP to be validated easily and clearly. A longer follow-up will be needed in order to ascertain whether the clinical outcome of these two approaches differs.

Relationship of aortic annular eccentricity and paravalvular regurgitation post transcatheter aortic valve implantation with CoreValve.

PubMed

Wong, Dennis T L; Bertaso, Angela G; Liew, Gary Y H; Thomson, Viji S; Cunnington, Michael S; Richardson, James D; Gooley, Robert; Lockwood, Siobhan; Meredith, Ian T; Worthley, Matthew I; Worthley, Stephen G

2013-04-01

Significant paravalvular aortic regurgitation (PAR) after transcatheter aortic valve implantation (TAVI) is associated with negative clinical consequences. We hypothesize that increased eccentricity of the aortic annulus is associated with greater PAR. Patients with severe aortic stenosis underwent multidetector computed tomography (MDCT) before successful TAVI with the Medtronic CoreValve bioprosthesis. The smallest (D(min)) and largest (D(max)) orthogonal diameters in the basal ring of the aortic annulus were determined. We defined circularity of aortic annulus using the eccentricity index (1 - D(min)/D(max)). The primary endpoint was early occurrence of significant PAR, defined as > grade II PAR by postprocedural aortography. Eighty-four patients, mean age 83 ± 4 years with a mean aortic valve area of 0.7 ± 0.2 cm² were included. Twenty patients had postprocedural PAR > grade II. Using a receiver operating characteristic (ROC) analysis, eccentricity index correlated with significant PAR (AUC = 0.834; P=.034). A retrospectively determined eccentricity index cut-off of >0.25 was related to significant PAR with a sensitivity of 80%, specificity of 86%, and negative predictive value of 95% (P<.001). On univariate logistic regression, eccentricity index of >0.25 (P<.001) and device implantation depth (P=.015) correlated with significant PAR, while other parameters such as annular calcification and cover index did not. On multivariate analysis including only parameters with P<.1 on univariate analysis, eccentricity index >0.25 was the sole independent predictor of significant PAR. Eccentricity index is related to significant PAR after TAVI with Medtronic CoreValve. Further larger studies are required to determine the utility of this novel index in screening suitable patients for this procedure.

Silicone septum leakage at the origin of a drug overdose in a patient implanted with an intrathecal pump.

PubMed

Perruchoud, Christophe; Bovy, Michèle; Rutschmann, Blaise; Durrer, Anne; Buchser, Eric

2013-01-01

Intrathecal (IT) pump failures usually result in decreased drug administration and symptom reoccurrence with or without withdrawal syndrome. We report a case of a leaking silicone septum associated to a systemic drug overdose. An 84-year-old patient treated with IT clonidine for chronic back pain presented with a state of confusion, visual hallucinations, and hypertension two hours after an unremarkable pump (SynchroMed EL, Medtronic, Minneapolis, MN, USA) refill. The reservoir was emptied and 14 mL (8.4 mg of clonidine) was found to be missing (difference between retrieved and expected volumes). The pump was refilled and a check on the next day showed again a loss of 3.5 mL. A malfunction was suspected and the pump was replaced (SynchroMed II, Medtronic). The inspection of the external surface of the pump revealed severe damage to the silicone septum with multiple gouges due to needle scarring. A fluid leak also was clearly seen through the septum. The signs and symptoms presented by this patient are consistent with clonidine overdose that resulted from a combination of a possible accidental pocket fill and a definite septum leak into the subcutaneous tissue. The damage to the silicone could be due to the loss of the nontraumatic properties of the Huber needles that are rubbed against the metallic case in attempting to locate the injection port during refill procedures. This observation is the first description of a silicone septum damage contributing to a pump dysfunction and drug overdose despite the use of appropriate needles for refilling. © 2012 International Neuromodulation Society.

Pacemaker dependency after transcatheter aortic valve implantation with the self-expanding Medtronic CoreValve System.

PubMed

van der Boon, Robert M A; Van Mieghem, Nicolas M; Theuns, Dominic A; Nuis, Rutger-Jan; Nauta, Sjoerd T; Serruys, Patrick W; Jordaens, Luc; van Domburg, Ron T; de Jaegere, Peter P T

2013-09-30

To determine pacemaker (PM) dependency at follow-up visit in patients who underwent new permanent pacemaker implantation (PPI) following transcatheter aortic valve implantation (TAVI). Single center prospective observational study including 167 patients without previous PM implantation who underwent TAVI with the self-expanding Medtronic CoreValve System (MCS) between November 2005 and February 2011. PM dependency was defined by the presence of a high degree atrioventricular block (HDAVB; second [AV2] and third degree [AV3B]), or a slow (<30 bpm) or absent ventricular escape rhythm during follow-up PM interrogation. A total of 36 patients (21.6%) received a new PM following TAVI. The indication for PM was AV2B (n=2, 5.6%), AV3B (n=28, 77.8%), postoperative symptomatic bradycardia (n=3, 8.3%), brady-tachy syndrome (n=1, 2.8%), atrial fibrilation with slow response (n=1, 2.8%) and left bundle branch block (n=1, 2.8%). Long term follow-up was complete for all patients and ranged from 1 to 40 months (median (IQR): 11.5 (5.0-18.0 months). Of those patients with a HDAVB, 16 out of the 30 patients (53.3%) were PM independent at follow-up visit (complete or partial resolution of the AV conduction abnormality). Overall, 20 out of the 36 patients (55.6%) who received a new PM following TAVI were PM independent at follow-up. Partial and even complete resolution of peri-operative AV conduction abnormalities after MCS valve implantation occurred in more than half of the patients. Copyright © 2012 Elsevier Ireland Ltd. All rights reserved.

Study design and rationale of the 'Balloon-Expandable Cobalt Chromium SCUBA Stent versus Self-Expandable COMPLETE-SE Nitinol Stent for the Atherosclerotic ILIAC Arterial Disease (SENS-ILIAC Trial) Trial': study protocol for a randomized controlled trial.

PubMed

Choi, Woong Gil; Rha, Seung Woon; Choi, Cheol Ung; Kim, Eung Ju; Oh, Dong Joo; Cho, Yoon Hyung; Park, Sang Ho; Lee, Seung Jin; Hur, Ae Yong; Ko, Young Guk; Park, Sang Min; Kim, Ki Chang; Kim, Joo Han; Kim, Min Woong; Kim, Sang Min; Bae, Jang Ho; Bong, Jung Min; Kang, Won Yu; Seo, Jae Bin; Jung, Woo Yong; Cho, Jang Hyun; Kim, Do Hoi; Ahn, Ji Hoon; Kim, Soo Hyun; Jang, Ji Yong

2016-06-25

The self-expandable COMPLETE™ stent (Medtronic) has greater elasticity, allowing it to regain its shape after the compression force reduces, and has higher trackability, thus is easier to maneuver through tortuous vessels, whereas the balloon-expandable SCUBA™ stent (Medtronic) has higher radial stiffness and can afford more accurate placement without geographic miss, which is important in aortoiliac bifurcation lesions. To date, there have been no randomized control trials comparing efficacy and safety between the self-expanding stent and balloon-expandable stent in advanced atherosclerotic iliac artery disease. The purpose of our study is to examine primary patency (efficacy) and incidence of stent fracture and geographic miss (safety) between two different major representative stents, the self-expanding nitinol stent (COMPLETE-SE™) and the balloon-expanding cobalt-chromium stent (SCUBA™), in stenotic or occlusive iliac arterial lesions. This trial is designed as a prospective, randomized, multicenter trial to demonstrate a noninferiority of SCUBA™ stent to COMPLETE-SE™ stent following balloon angioplasty in iliac arterial lesions, and a total of 280 patients will be enrolled. The primary end point of this study is the rate of primary patency in the treated segment at 12 months after intervention as determined by catheter angiography, computed tomography angiography, or duplex ultrasound. The SENS-ILIAC trial will give powerful insight into whether the stent choice according to deployment mechanics would impact stent patency, geographic miss, or stent fracture in patients undergoing stent implantation in iliac artery lesions. National Institutes of Health Clinical Trials Registry (ClinicalTrials.gov identifier: NCT01834495 ), registration date: May 8, 2012.

Eight-year results of aortic root replacement with the freestyle stentless porcine aortic root bioprosthesis.

PubMed

Kon, Neal D; Riley, Robert D; Adair, Sandy M; Kitzman, Dalane W; Cordell, A Robert

2002-06-01

Stentless porcine aortic valves offer several advantages over traditional valves. Among these are superior hemodynamics, laminar flow patterns, lack of need for anticoagulation, and perhaps improved durability. One hundred four patients were operated on from September 17, 1992, to October 31, 1997, as part of a multicenter worldwide investigation of the Medtronic Freestyle stentless porcine bioprosthesis. All patients received a total aortic root replacement. The patients were evaluated postoperatively at discharge, at 3 to 6 months, and yearly by clinical examination and color flow Doppler echocardiography. Operative mortality was 3.9%. No patient experienced structural valve deterioration, nonstructural deterioration, perivalvular leak, or unacceptable hemodynamic performance. At 8 years, survival was 59.8%. Freedom from thromboembolic complications was 83.3%. Freedom from postoperative endocarditis was 96.9%. Freedom from reoperation was 100%. Mean systolic gradients did not change over the time period studied. They were 6.4 +/- 3.8 mm Hg at 1 year and 6.7 +/- 2.6 mm Hg at 8 years. Correspondingly, effective orifice area was 1.9 +/- 0.7 cm2 at 1 year and 1.8 +/- 0.8 cm2 at 8 years. The incidence of any aortic insufficiency also did not change over the length of follow-up. At 1 year, 98% of patients had no or trivial aortic insufficiency and 2% had mild aortic insufficiency. At 8 years, 100% of patients evaluated were free of any aortic insufficiency. The Medtronic Freestyle aortic root bioprosthesis can be used safely to replace the aortic root or aortic valve for aortic valve and aortic root pathology. Total root replacement allows optimal hemodynamic performance with no significant aortic regurgitation. Results up to 8 years show excellent survival and no signs of degeneration. Further follow-up is still needed to determine valve durability.

Accuracy of a new real-time continuous glucose monitoring algorithm.

PubMed

Keenan, D Barry; Cartaya, Raymond; Mastrototaro, John J

2010-01-01

Through minimally invasive sensor-based continuous glucose monitoring (CGM), individuals can manage their blood glucose (BG) levels more aggressively, thereby improving their hemoglobin A1c level, while reducing the risk of hypoglycemia. Tighter glycemic control through CGM, however, requires an accurate glucose sensor and calibration algorithm with increased performance at lower BG levels. Sensor and BG measurements for 72 adult and adolescent subjects were obtained during the course of a 26-week multicenter study evaluating the efficacy of the Paradigm REAL-Time (PRT) sensor-augmented pump system (Medtronic Diabetes, Northridge, CA) in an outpatient setting. Subjects in the study arm performed at least four daily finger stick measurements. A retrospective analysis of the data set was performed to evaluate a new calibration algorithm utilized in the Paradigm Veo insulin pump (Medtronic Diabetes) and to compare these results to performance metrics calculated for the PRT. A total of N = 7193 PRT sensor downloads for 3 days of use, as well as 90,472 temporally and nonuniformly paired data points (sensor and meter values), were evaluated, with 5841 hypoglycemic and 15,851 hyperglycemic events detected through finger stick measurements. The Veo calibration algorithm decreased the overall mean absolute relative difference by greater than 0.25 to 15.89%, with hypoglycemia sensitivity increased from 54.9% in the PRT to 82.3% in the Veo (90.5% with predictive alerts); however, hyperglycemia sensitivity was decreased only marginally from 86% in the PRT to 81.7% in the Veo. The Veo calibration algorithm, with sensor error reduced significantly in the 40- to 120-mg/dl range, improves hypoglycemia detection, while retaining accuracy at high glucose levels. 2010 Diabetes Technology Society.

Sacral nerve stimulation for neuromodulation of the lower urinary tract.

PubMed

Hubsher, Chad P; Jansen, Robert; Riggs, Dale R; Jackson, Barbara J; Zaslau, Stanley

2012-10-01

Sacral neuromodulation (SNM) has become a standard treatment option for patients suffering from urinary urge incontinence, urgency-frequency, and/or nonobstructive urinary retention refractory to conservative and pharmacologic treatment. Since its initial development, the manufacturer of InterStim therapy (Medtronic, Inc., Minneapolis, MN, USA), has introduced technical modifications, while surgeons and researchers have adapted and published various innovations and alterations of the implantation technique. In this article, we feature our SNM technique including patient selection, comprehensive dialogue/evaluation, procedure details, and appropriate follow up. Although there is often great variability in patients with lower urinary tract dysfunction, we maintain that great success can be achieved with a systematic and methodical approach to SNM.

Transcatheter Heart Valve Selection and Permanent Pacemaker Implantation in Patients With Pre-Existent Right Bundle Branch Block.

PubMed

van Gils, Lennart; Tchetche, Didier; Lhermusier, Thibault; Abawi, Masieh; Dumonteil, Nicolas; Rodriguez Olivares, Ramón; Molina-Martin de Nicolas, Javier; Stella, Pieter R; Carrié, Didier; De Jaegere, Peter P; Van Mieghem, Nicolas M

2017-03-03

Right bundle branch block is an established predictor for new conduction disturbances and need for a permanent pacemaker (PPM) after transcatheter aortic valve replacement. The aim of the study was to evaluate the absolute rates of transcatheter aortic valve replacement related PPM implantations in patients with pre-existent right bundle branch block and categorize for different transcatheter heart valves. We pooled data on 306 transcatheter aortic valve replacement patients from 4 high-volume centers in Europe and selected those with right bundle branch block at baseline without a previously implanted PPM. Logistic regression was used to evaluate whether PPM rate differed among transcatheter heart valves after adjustment for confounders. Mean age was 83±7 years and 63% were male. Median Society of Thoracic Surgeons score was 6.3 (interquartile range, 4.1-10.2). The following transcatheter valve designs were used: Medtronic CoreValve (n=130; Medtronic, Minneapolis, MN); Edwards Sapien XT (ES-XT; n=124) and Edwards Sapien 3 (ES-3; n=32; Edwards Lifesciences, Irvine, CA); and Boston Scientific Lotus (n=20; Boston Scientific Corporation, Marlborough, MA). Overall permanent pacemaker implantation rate post-transcatheter aortic valve replacement was 41%, and per valve design: 75% with Lotus, 46% with CoreValve, 32% with ES-XT, and 34% with ES-3. The indication for PPM implantation was total atrioventricular block in 98% of the cases. Lotus was associated with a higher PPM rate than all other valves. PPM rate did not differ between ES-XT and ES-3. Ventricular paced rhythm at 30-day and 1-year follow-up was present in 81% at 89%, respectively. Right bundle branch block at baseline is associated with a high incidence of PPM implantation for all transcatheter heart valves. PPM rate was highest for Lotus and lowest for ES-XT and ES-3. Pacemaker dependency remained high during follow-up. © 2017 The Authors. Published on behalf of the American Heart Association, Inc., by Wiley Blackwell.

Targeting bed nucleus of the stria terminalis for severe obsessive-compulsive disorder: more unexpected lead placement in obsessive-compulsive disorder than in surgery for movement disorders.

PubMed

Nuttin, Bart; Gielen, Frans; van Kuyck, Kris; Wu, Hemmings; Luyten, Laura; Welkenhuysen, Marleen; Brionne, Thomas C; Gabriëls, Loes

2013-01-01

In preparation for a multicenter study, a protocol was written on how to perform surgical targeting of the bed nucleus of the stria terminalis, based on the lead implantation experience in patients with treatment-refractory obsessive-compulsive disorder (OCD) at the Universitaire Ziekenhuizen Leuven (UZ Leuven). When analyzing the postoperative images, we were struck by the fact that the difference between the postoperative position of the leads and the planned position seemed larger than expected. The precision of targeting in four patients with severe OCD who received bilateral model 3391 leads (Medtronic) was compared with the precision of targeting in the last seven patients who underwent surgery at UZ Leuven for movement disorders (four with Parkinson disease and three with essential tremor; all received bilateral leads). Because the leads implanted in six of the seven patients with movement disorders were model 3387 leads (Medtronic), targeting precision was also analyzed in four patients with OCD in whom model 3387 leads were implanted in the same target as the other patients with OCD. In the patients with OCD, every implanted lead deviated at least 1.3 mm from its intended position in at least one of three directions (lateral, anteroposterior, and depth), whereas in the patients with movement disorders, the maximal deviation of any of all implanted leads was 1.3 mm. The deviations in lead placement were comparable in patients with OCD who received a model 3387 implant and patients who received a model 3391 implant. In the patients with OCD, all leads were implanted more posteriorly than planned. The cause of the posterior deviation could not be determined with certainty. The most likely cause was an increased mechanical resistance of the brain tissue along the trajectory when following the targeting protocol compared with the trajectories classically used for subthalamic nucleus or ventral intermediate nucleus of the thalamus stimulation. Copyright © 2013 Elsevier Inc. All rights reserved.

Implantation of the Medtronic Harmony Transcatheter Pulmonary Valve Improves Right Ventricular Size and Function in an Ovine Model of Postoperative Chronic Pulmonary Insufficiency.

PubMed

Schoonbeek, Rosanne C; Takebayashi, Satoshi; Aoki, Chikashi; Shimaoka, Toru; Harris, Matthew A; Fu, Gregory L; Kim, Timothy S; Dori, Yoav; McGarvey, Jeremy; Litt, Harold; Bouma, Wobbe; Zsido, Gerald; Glatz, Andrew C; Rome, Jonathan J; Gorman, Robert C; Gorman, Joseph H; Gillespie, Matthew J

2016-10-01

Pulmonary insufficiency is the nexus of late morbidity and mortality after transannular patch repair of tetralogy of Fallot. This study aimed to establish the feasibility of implantation of the novel Medtronic Harmony transcatheter pulmonary valve (hTPV) and to assess its effect on pulmonary insufficiency and ventricular function in an ovine model of chronic postoperative pulmonary insufficiency. Thirteen sheep underwent baseline cardiac magnetic resonance imaging, surgical pulmonary valvectomy, and transannular patch repair. One month after transannular patch repair, the hTPV was implanted, followed by serial magnetic resonance imaging and computed tomography imaging at 1, 5, and 8 month(s). hTPV implantation was successful in 11 animals (85%). There were 2 procedural deaths related to ventricular fibrillation. Seven animals survived the entire follow-up protocol, 5 with functioning hTPV devices. Two animals had occlusion of hTPV with aneurysm of main pulmonary artery. A strong decline in pulmonary regurgitant fraction was observed after hTPV implantation (40.5% versus 8.3%; P=0.011). Right ventricular end diastolic volume increased by 49.4% after transannular patch repair (62.3-93.1 mL/m 2 ; P=0.028) but was reversed to baseline values after hTPV implantation (to 65.1 mL/m 2 at 8 months, P=0.045). Both right ventricular ejection fraction and left ventricular ejection fraction were preserved after hTPV implantation. hTPV implantation is feasible, significantly reduces pulmonary regurgitant fraction, facilitates right ventricular volume improvements, and preserves biventricular function in an ovine model of chronic pulmonary insufficiency. This percutaneous strategy could potentially offer an alternative for standard surgical pulmonary valve replacement in dilated right ventricular outflow tracts, permitting lower risk, nonsurgical pulmonary valve replacement in previously prohibitive anatomies. © 2016 American Heart Association, Inc.

The PILGRIM study: in silico modeling of a predictive low glucose management system and feasibility in youth with type 1 diabetes during exercise.

PubMed

Danne, Thomas; Tsioli, Christiana; Kordonouri, Olga; Blaesig, Sarah; Remus, Kerstin; Roy, Anirban; Keenan, Barry; Lee, Scott W; Kaufman, Francine R

2014-06-01

Predictive low glucose management (PLGM) may help prevent hypoglycemia by stopping insulin pump delivery based on predicted sensor glucose values. Hypoglycemic challenges were simulated using the Food and Drug Administration-accepted glucose simulator with 100 virtual patients. PLGM was then tested with a system composed of a Paradigm(®) insulin pump (Medtronic, Northridge, CA), an Enlite™ glucose sensor (Medtronic), and a BlackBerry(®) (Waterloo, ON, Canada)-based controller. Subjects (n=22) on continuous subcutaneous insulin infusion (five females, 17 males; median [range] age, 15 [range, 14-20] years; median [range] diabetes duration, 7 [2-14] years; median [range] glycated hemoglobin, 8.0% [6.7-10.4%]) exercised until the PLGM system suspended insulin delivery or until the reference blood glucose value (HemoCue(®); HemoCue GmbH, Großostheim, Germany) reached the predictive suspension threshold setting. PLGM reduced hypoglycemia (<70 mg/dL) in silico by 26.7% compared with no insulin suspension, as opposed to a 5.3% reduction in hypoglycemia with use of low glucose suspend (LGS). The median duration of hypoglycemia (time spent <70 mg/dL) with PLGM was significantly less than with LGS (58 min vs. 101 min, respectively; P<0.001). In the clinical trial the hypoglycemic threshold during exercise was reached in 73% of the patients, and hypoglycemia was prevented in 80% of the successful experiments. The mean (±SD) sensor glucose at predictive suspension was 92±7 mg/dL, resulting in a postsuspension nadir (by HemoCue) of 77±22 mg/dL. The suspension lasted for 90±35 (range, 30-120) min, resulting in a sensor glucose level at insulin resumption of 97±19 mg/dL. In silico modeling and early feasibility data demonstrate that PLGM may further reduce the severity of hypoglycemia beyond that already established for algorithms that use a threshold-based suspension.

Spinal cord stimulation (SCS) in conjunction with peripheral nerve field stimulation (PNfS) for the treatment of complex pain in failed back surgery syndrome (FBSS).

PubMed

Reverberi, Claudio; Dario, Alessandro; Barolat, Giancarlo

2013-01-01

Failed back surgery syndrome (FBSS) is a well-defined pathologic condition observed over many years. We have investigated the effect of spinal cord stimulation (SCS) with peripheral nerve field stimulation (PNfS) in eight patients with FBSS. The following parameters were collected and analyzed: The pain intensity score on a 0-10 numbering rating scale (NRS), the psychologic profile with Beck Depression Inventory (BDI), the pain quality with McGill Pain Questionnaire-short form (MGPQ-sf), the back pain with Oswestry scale score (OS), and the health general quality pattern with QualityMetric's SF-36v2(®) Health Survey. Eight patients with low back and radicular pain in FBSS are reported. The mean duration of pain was 6.7 months, and the mean NRS score was 9.5, BDI 28.8, MGPQ-sf 16.8, OS 44.5, and SF-36 score was 72.8. The average drug intake of opioids was 250 mg/day. In six patients, two octopolar leads were placed in epidural space at D7-D8 and D8-D9, in conjunction with two octopolar leads placed in lumbar-sacral subcutaneous space (Precision System, Boston Scientific, Valencia, CA, USA), and in two patients, a two tetrapolar leads was placed in epidural space at D8-D9 with two tetrapolar leads (Pisces Quad, Plus, Medtronic Inc., Minneapolis, MN, USA) placed in lumbar-sacral subcutaneous space (Restore Ultra, Medtronic Inc., Minneapolis, MN, USA). After one year mean of follow-up, the mean NRS score was 4, BDI 8, MGPQ-sf 5, OS 21, and the SF-36 score was increased at 108.5. The mean drug intake of opioids was decreased at 20 mg/day. The combination of SCS and PNfS, using the latest rechargeable systems, may be a valid therapeutic strategy in FBSS. © 2012 International Neuromodulation Society.

The influence of current direction on phosphene thresholds evoked by transcranial magnetic stimulation.

PubMed

Kammer, T; Beck, S; Erb, M; Grodd, W

2001-11-01

To quantify phosphene thresholds evoked by transcranial magnetic stimulation (TMS) in the occipital cortex as a function of induced current direction. Phosphene thresholds were determined in 6 subjects. We compared two stimulator types (Medtronic-Dantec and Magstim) with monophasic pulses using the standard figure-of-eight coils and systematically varied hemisphere (left and right) and induced current direction (latero-medial and medio-lateral). Each measurement was made 3 times, with a new stimulation site chosen for each repetition. Only those stimulation sites were investigated where phosphenes were restricted to one visual hemifield. Coil positions were stereotactically registered. Functional magnetic resonance imaging (fMRI) of retinotopic areas was performed in 5 subjects to individually characterize the borders of visual areas; TMS stimulation sites were coregistered with respect to visual areas. Despite large interindividual variance we found a consistent pattern of phosphene thresholds. They were significantly lower if the direction of the induced current was oriented from lateral to medial in the occipital lobe rather than vice versa. No difference with respect to the hemisphere was found. Threshold values normalized to the square root of the stored energy in the stimulators were lower with the Medtronic-Dantec device than with the Magstim device. fMRI revealed that stimulation sites generating unilateral phosphenes were situated at V2 and V3. Variability of phosphene thresholds was low within a cortical patch of 2x2cm(2). Stimulation over V1 yields phosphenes in both visual fields. The excitability of visual cortical areas depends on the direction of the induced current with a preference for latero-medial currents. Although the coil positions used in this study were centered over visual areas V2 and V3, we cannot rule out the possibility that subcortical structures or V1 could actually be the main generator for phosphenes.

Treatment of Symptomatic Severe Aortic Stenosis With a Novel Resheathable Supra-Annular Self-Expanding Transcatheter Aortic Valve System.

PubMed

Manoharan, Ganesh; Walton, Antony S; Brecker, Stephen J; Pasupati, Sanjeevan; Blackman, Daniel J; Qiao, Hongyan; Meredith, Ian T

2015-08-24

The purpose of this study was to prospectively evaluate the safety and clinical performance of the CoreValve Evolut R transcatheter aortic valve replacement (TAVR) system (Medtronic, Inc., Minneapolis, Minnesota) in a single-arm, multicenter pivotal study in high- or extreme-risk patients with symptomatic aortic valve stenosis. Although outcomes following TAVR are improving, challenges still exist. The repositionable 14-F equivalent CoreValve Evolut R TAVR system was developed to mitigate some of these challenges. Suitable patients (n = 60) underwent TAVR with a 26- or 29-mm Evolut R valve. Primary safety endpoints were mortality and stroke at 30 days. Primary clinical performance endpoints were device success per the VARC-2 (Valve Academic Research Consortium-2) and the percent of patients with mild or less aortic regurgitation 24 h to 7 days post-procedure. Patients (66.7% female; mean age 82.8 ± 6.1 years; Society of Thoracic Surgeons Score 7.0 ± 3.7%) underwent TAVR via the transfemoral route in 98.3%, using a 29-mm valve in 68.3% of patients. All attempts at repositioning were successful. No death or stroke was observed up to 30 days. The VARC-2 overall device success rate was 78.6%. Paravalvular regurgitation post TAVR was mild or less in 96.6%, moderate in 3.4%, and severe in 0% at 30 days. Major vascular complications occurred in 8.3%, and permanent pacemaker implantation was required in 11.7% of patients. The repositionable 14-F equivalent Evolut R TAVR system is safe and effective at treating high-risk symptomatic aortic stenosis patients. Repositioning was successful when required in all patients, with low rates of moderate or severe paravalvular aortic regurgitation and low permanent pacemaker implantation. (The Medtronic CoreValve™ Evolut R™ CE Mark Clinical Study; NCT01876420). Copyright © 2015 American College of Cardiology Foundation. Published by Elsevier Inc. All rights reserved.

Renal denervation in treatment-resistant essential hypertension. A randomized, SHAM-controlled, double-blinded 24-h blood pressure-based trial.

PubMed

Mathiassen, Ole N; Vase, Henrik; Bech, Jesper N; Christensen, Kent L; Buus, Niels H; Schroeder, Anne P; Lederballe, Ole; Rickers, Hans; Kampmann, Ulla; Poulsen, Per L; Hansen, Klavs W; Btker, Hans E; Peters, Christian D; Engholm, Morten; Bertelsen, Jannik B; Lassen, Jens F; Langfeldt, Sten; Andersen, Gratien; Pedersen, Erling B; Kaltoft, Anne

2016-08-01

Renal denervation (RDN), treating resistant hypertension, has, in open trial design, been shown to lower blood pressure (BP) dramatically, but this was primarily with respect to office BP. We conducted a SHAM-controlled, double-blind, randomized, single-center trial to establish efficacy data based on 24-h ambulatory BP measurements (ABPM). Inclusion criteria were daytime systolic ABPM at least 145 mmHg following 1 month of stable medication and 2 weeks of compliance registration. All RDN procedures were carried out by an experienced operator using the unipolar Medtronic Flex catheter (Medtronic, Santa Rosa, California, USA). We randomized 69 patients with treatment-resistant hypertension to RDN (n = 36) or SHAM (n = 33). Groups were well balanced at baseline. Mean baseline daytime systolic ABPM was 159 ± 12 mmHg (RDN) and 159 ± 14 mmHg (SHAM). Groups had similar reductions in daytime systolic ABPM compared with baseline at 3 months [-6.2 ± 18.8 mmHg (RDN) vs. -6.0 ± 13.5 mmHg (SHAM)] and at 6 months [-6.1 ± 18.9 mmHg (RDN) vs. -4.3 ± 15.1 mmHg (SHAM)]. Mean usage of antihypertensive medication (daily defined doses) at 3 months was equal [6.8 ± 2.7 (RDN) vs. 7.0 ± 2.5 (SHAM)].RDN performed at a single center and by a high-volume operator reduced ABPM to the same level as SHAM treatment and thus confirms the result of the HTN3 trial. Further, clinical use of RDN for treatment of resistant hypertension should await positive results from double-blinded, SHAM-controlled trials with multipolar ablation catheters or novel denervation techniques.

Management of Deep Brain Stimulator Battery Failure: Battery Estimators, Charge Density, and Importance of Clinical Symptoms

PubMed Central

Fakhar, Kaihan; Hastings, Erin; Butson, Christopher R.; Foote, Kelly D.; Zeilman, Pam; Okun, Michael S.

2013-01-01

Objective We aimed in this investigation to study deep brain stimulation (DBS) battery drain with special attention directed toward patient symptoms prior to and following battery replacement. Background Previously our group developed web-based calculators and smart phone applications to estimate DBS battery life (http://mdc.mbi.ufl.edu/surgery/dbs-battery-estimator). Methods A cohort of 320 patients undergoing DBS battery replacement from 2002–2012 were included in an IRB approved study. Statistical analysis was performed using SPSS 20.0 (IBM, Armonk, NY). Results The mean charge density for treatment of Parkinson’s disease was 7.2 µC/cm2/phase (SD = 3.82), for dystonia was 17.5 µC/cm2/phase (SD = 8.53), for essential tremor was 8.3 µC/cm2/phase (SD = 4.85), and for OCD was 18.0 µC/cm2/phase (SD = 4.35). There was a significant relationship between charge density and battery life (r = −.59, p<.001), as well as total power and battery life (r = −.64, p<.001). The UF estimator (r = .67, p<.001) and the Medtronic helpline (r = .74, p<.001) predictions of battery life were significantly positively associated with actual battery life. Battery status indicators on Soletra and Kinetra were poor predictors of battery life. In 38 cases, the symptoms improved following a battery change, suggesting that the neurostimulator was likely responsible for symptom worsening. For these cases, both the UF estimator and the Medtronic helpline were significantly correlated with battery life (r = .65 and r = .70, respectively, both p<.001). Conclusions Battery estimations, charge density, total power and clinical symptoms were important factors. The observation of clinical worsening that was rescued following neurostimulator replacement reinforces the notion that changes in clinical symptoms can be associated with battery drain. PMID:23536810

Device landing zone calcification and its impact on residual regurgitation after transcatheter aortic valve implantation with different devices.

PubMed

Seiffert, Moritz; Fujita, Buntaro; Avanesov, Maxim; Lunau, Clemens; Schön, Gerhard; Conradi, Lenard; Prashovikj, Emir; Scholtz, Smita; Börgermann, Jochen; Scholtz, Werner; Schäfer, Ulrich; Lund, Gunnar; Ensminger, Stephan; Treede, Hendrik

2016-05-01

Calcification of the device landing zone is linked to paravalvular regurgitation after transcatheter aortic valve implantation (TAVI). The mechanisms remain incompletely understood and the performance of next-generation transcatheter heart valves (THV) has not been investigated. We evaluated the impact of calcification patterns on residual aortic regurgitation (AR) after TAVI with different THV in patients with severe aortic stenosis. TAVI was performed in 537 patients at two centres. Devices implanted were the Edwards Sapien XT (n = 254), Medtronic CoreValve (n = 123), JenaValve (n = 62), Medtronic Engager (n = 56), and Symetis Acurate (n = 42) prostheses. Calcification of the device landing zone was retrospectively assessed from contrast-enhanced multidetector computed tomography data and correlated with echocardiographic and clinical data. Calcium volumes of the aortic valve and left-ventricular outflow tract were associated with residual AR: No AR, 604 mm(3) (inter-quartile range, IQR 349-916); trace AR, 639 mm(3) (IQR 368-948); mild AR, 710 mm(3) (IQR 412-2078); ≥moderate AR, 1041 mm(3) (IQR 791-1417, P = 0.001). Device landing zone calcium, particularly if located in the left-ventricular outflow tract, and a low cover index were predictive of AR. Differences in the incidence of AR were observed with regard to THV type. Higher calcium volume was associated with the need for post-dilation (n = 134, median 852 [IQR 342-945] vs. 604 [IQR 542-1207] mm(3), P < 0.001). Calcification of the device landing zone, particularly if located inferior to the annulus, was independently associated with residual AR after TAVI with all evaluated THV; however, the incidence of paravalvular leakage differed significantly between the devices implanted. Published on behalf of the European Society of Cardiology. All rights reserved. © The Author 2015. For permissions please email: journals.permissions@oup.com.

An industry update: the latest developments in Therapeutic delivery.

PubMed

Steinbach, Oliver C

2018-05-01

The present industry update covers the period of 1 January-31 January 2018, with information sourced from company press releases, regulatory and patent agencies as well as scientific literature. Several public offerings (Gecko, Insmed), licensing (Foresee) and commercialization agreements (Alnylam, Collegium Pharmaceutical) as well as patent filings (Elute) continue to prove the sustained investments in the drug delivery market. In increasing numbers, more effective ways to deliver the active ingredient to the right location and the right dose through devices (Boehringer Ingelheim's Respimat, Medtronics' SynchroMedII) or improved compound properties through formulation (Aquestive Therapeutics' PharmFilm, Noven Pharmaceuticals' transdermal patch) are reaching the market. Furthering biologics and gene delivery (Avacta, Bracco) proves that novel drug delivery technologies are successfully addressing more challenging drug formats.

Results of endovascular repair of the thoracic aorta with the Talent Thoracic stent graft: the Talent Thoracic Retrospective Registry.

PubMed

Fattori, Rossella; Nienaber, Christoph A; Rousseau, Hervé; Beregi, Jean-Paul; Heijmen, Robin; Grabenwöger, Martin; Piquet, Philippe; Lovato, Luigi; Dabbech, Chaouki; Kische, Stephan; Gaxotte, Virginia; Schepens, Marc; Ehrlich, Marek; Bartoli, Jean-Michelle

2006-08-01

Endovascular treatment of thoracic aortic diseases demonstrated low perioperative morbidity and mortality when compared with conventional open repair. Long-term effectiveness of this minimally invasive technique remains to be proven. The Talent Thoracic Retrospective Registry was designed to evaluate the impact of this therapy on patients treated in 7 major European referral centers over an 8-year period. Data from 457 consecutive patients (113 emergency and 344 elective cases) who underwent endovascular thoracic aortic repair with the Medtronic Talent Thoracic stent graft (Medtronic/AVE, Santa Rosa, Calif) were collected. Follow-up analysis (24 +/- 19.4 months, range 1-85.1 months) was based on clinical and imaging findings, including all adverse events. To ensure consistency of data interpretation and event reporting, one physician reviewed all adverse events and deaths for the whole cohort of patients. In the case of discrepancies, the treating physicians were queried. Among 422 patients who survived the interventional procedure (in-hospital mortality 5%, 23 patients), mortality during follow-up was 8.5% (36 patients), and in 11 of them the death was related to the aortic disease. Persistent endoleak was reported at imaging follow-up in 64 cases: 44 were primary (9.6%) and 21 occurred during follow-up (4.9%). Seven patients with persistent endoleak had aortic rupture during follow-up, at a variable time from 40 days to 35 months, and all subsequently died. A minor incidence of migration of the stent graft (7 cases), graft fabric alteration (2 cases), and modular disconnection (3 cases) was observed at imaging. Kaplan-Meier overall survival estimate at 1 year was 90.97%, at 3 years was 85.36%, and at 5 years was 77.49%. At the same intervals, freedom from a second procedure (either open conversion or endovascular) was 92.45%, 81.3%, and 70.0%, respectively. Endovascular treatment for thoracic aortic disease with the Talent stent graft is associated with low early morbidity and mortality rates also for patients who are at high risk and treated on an emergency basis. Follow-up data indicate a substantial durability of the procedure with a high freedom from related death and secondary interventions.

Mid- to long-term outcome comparison of the Medtronic Hancock II and bi-leaflet mechanical aortic valve replacement in patients younger than 60 years of age: a propensity-matched analysis.

PubMed

Wang, Yin; Chen, Si; Shi, Jiawei; Li, Geng; Dong, Nianguo

2016-03-01

This study aims to compare mid-long-term clinical outcomes between patients younger than 60 years of age undergoing bioprosthetic and mechanical aortic valve replacement. From January 2002 to December 2009, patients younger than 60 years of age who received Medtronic Hancock II porcine bioprostheses were selected and compared with those who received mechanical bi-leaflet valves in the aortic position. A stepwise logistic regression propensity score identified a subset of 112 evenly matched patient-pairs. Mid-long-term outcomes of survival, valve-related reoperations, thromboembolic events and bleeding events were assessed. The follow-up was only 95.1% complete. Fourteen measurable variables were statistically similar for the matched cohort. Postoperative in-hospital mortality was 3.6% (bioprosthetic valves) and 2.7% (mechanical valves) (P = 0.700). Survival at 5 and 10 years was 96.3 and 88.7% for patients receiving bioprosthetic valve replacement versus 96.3 and 87.9% for patients receiving mechanical valve replacement (P = 0.860), respectively. At 5 and 10 years after operations, freedom from valve-related reoperation was 97.2 and 94.8% for patients receiving mechanical valve replacement, and 96.3 and 90.2% for patients receiving bioprosthetic valve replacement (P = 0.296), respectively. There was no difference between freedom from thromboembolic events (P = 0.528) and bleeding events (P = 0.128) between the matched groups during the postoperative 10 years. In patients younger than 60 years of age undergoing aortic valve replacement, mid-long-term survival rate was similar for patients receiving bioprosthetic versus mechanical valve replacement. Bioprosthetic valves were associated with a trend for a lower risk of anticoagulation treatment and did not have significantly greater likelihood of a reoperation. These findings suggest that a bioprosthetic valve may be a reasonable choice for AVR in patients younger than 60 years of age. © The Author 2015. Published by Oxford University Press on behalf of the European Association for Cardio-Thoracic Surgery. All rights reserved.

Relationship between the logistic EuroSCORE and the Society of Thoracic Surgeons Predicted Risk of Mortality score in patients implanted with the CoreValve ReValving system--a Bern-Rotterdam Study.

PubMed

Piazza, Nicolo; Wenaweser, Peter; van Gameren, Menno; Pilgrim, Thomas; Tzikas, Apostolos; Tsikas, Apostolos; Otten, Amber; Nuis, Rutger; Onuma, Yoshinobu; Cheng, Jin Ming; Kappetein, A Pieter; Boersma, Eric; Juni, Peter; de Jaegere, Peter; Windecker, Stephan; Serruys, Patrick W

2010-02-01

Surgical risk scores, such as the logistic EuroSCORE (LES) and Society of Thoracic Surgeons Predicted Risk of Mortality (STS) score, are commonly used to identify high-risk or "inoperable" patients for transcatheter aortic valve implantation (TAVI). In Europe, the LES plays an important role in selecting patients for implantation with the Medtronic CoreValve System. What is less clear, however, is the role of the STS score of these patients and the relationship between the LES and STS. The purpose of this study is to examine the correlation between LES and STS scores and their performance characteristics in high-risk surgical patients implanted with the Medtronic CoreValve System. All consecutive patients (n = 168) in whom a CoreValve bioprosthesis was implanted between November 2005 and June 2009 at 2 centers (Bern University Hospital, Bern, Switzerland, and Erasmus Medical Center, Rotterdam, The Netherlands) were included for analysis. Patient demographics were recorded in a prospective database. Logistic EuroSCORE and STS scores were calculated on a prospective and retrospective basis, respectively. Observed mortality was 11.1%. The mean LES was 3 times higher than the mean STS score (LES 20.2% +/- 13.9% vs STS 6.7% +/- 5.8%). Based on the various LES and STS cutoff values used in previous and ongoing TAVI trials, 53% of patients had an LES > or =15%, 16% had an STS > or =10%, and 40% had an LES > or =20% or STS > or =10%. Pearson correlation coefficient revealed a reasonable (moderate) linear relationship between the LES and STS scores, r = 0.58, P < .001. Although the STS score outperformed the LES, both models had suboptimal discriminatory power (c-statistic, 0.49 for LES and 0.69 for STS) and calibration. Clinical judgment and the Heart Team concept should play a key role in selecting patients for TAVI, whereas currently available surgical risk score algorithms should be used to guide clinical decision making. Copyright (c) 2010 Mosby, Inc. All rights reserved.

Complexity of Continuous Glucose Monitoring Data in Critically Ill Patients: Continuous Glucose Monitoring Devices, Sensor Locations, and Detrended Fluctuation Analysis Methods

PubMed Central

Signal, Matthew; Thomas, Felicity; Shaw, Geoffrey M.; Chase, J. Geoffrey

2013-01-01

Background Critically ill patients often experience high levels of insulin resistance and stress-induced hyperglycemia, which may negatively impact outcomes. However, evidence surrounding the causes of negative outcomes remains inconclusive. Continuous glucose monitoring (CGM) devices allow researchers to investigate glucose complexity, using detrended fluctuation analysis (DFA), to determine whether it is associated with negative outcomes. The aim of this study was to investigate the effects of CGM device type/calibration and CGM sensor location on results from DFA. Methods This study uses CGM data from critically ill patients who were each monitored concurrently using Medtronic iPro2s on the thigh and abdomen and a Medtronic Guardian REAL-Time on the abdomen. This allowed interdevice/calibration type and intersensor site variation to be assessed. Detrended fluctuation analysis is a technique that has previously been used to determine the complexity of CGM data in critically ill patients. Two variants of DFA, monofractal and multifractal, were used to assess the complexity of sensor glucose data as well as the precalibration raw sensor current. Monofractal DFA produces a scaling exponent (H), where H is inversely related to complexity. The results of multifractal DFA are presented graphically by the multifractal spectrum. Results From the 10 patients recruited, 26 CGM devices produced data suitable for analysis. The values of H from abdominal iPro2 data were 0.10 (0.03–0.20) higher than those from Guardian REAL-Time data, indicating consistently lower complexities in iPro2 data. However, repeating the analysis on the raw sensor current showed little or no difference in complexity. Sensor site had little effect on the scaling exponents in this data set. Finally, multifractal DFA revealed no significant associations between the multifractal spectrums and CGM device type/calibration or sensor location. Conclusions Monofractal DFA results are dependent on the device/calibration used to obtain CGM data, but sensor location has little impact. Future studies of glucose complexity should consider the findings presented here when designing their investigations. PMID:24351175

Stent thrombosis and major clinical events at 3 years after zotarolimus-eluting or sirolimus-eluting coronary stent implantation: a randomised, multicentre, open-label, controlled trial.

PubMed

Camenzind, Edoardo; Wijns, William; Mauri, Laura; Kurowski, Volkhard; Parikh, Keyur; Gao, Runlin; Bode, Christoph; Greenwood, John P; Boersma, Eric; Vranckx, Pascal; McFadden, Eugene; Serruys, Patrick W; O'Neil, William W; Jorissen, Brenda; Van Leeuwen, Frank; Steg, Ph Gabriel

2012-10-20

We sought to compare the long-term safety of two devices with different antiproliferative properties: the Endeavor zotarolimus-eluting stent (E-ZES; Medtronic, Inc) and the Cypher sirolimus-eluting stent (C-SES; Cordis, Johnson & Johnson) in a broad group of patients and lesions. Between May 21, 2007 and Dec 22, 2008, we recruited 8791 patients from 36 recruiting countries to participate in this open-label, multicentre, randomised, superiority trial. Eligible patients were those aged 18 years or older undergoing elective, unplanned, or emergency procedures in native coronary arteries. Patients were randomly assigned to either receive E-ZES and C-SES (ratio 1:1). Randomisation was stratified per centre with varying block sizes of four, six, or eight patients, and concealed with a central telephone-based or web-based allocation service. The primary outcome was definite or probable stent thrombosis at 3 years and was analysed by intention to treat. Patients and investigators were aware of treatment assignment. This trial is registered with ClinicalTrials.gov, number NCT00476957. PROTECT randomised 8791 patients, of whom 8709 provided consent to participate and were eligible: 4357 were allocated to the E-ZES group and 4352 patients to the C-SES group. At 3 years, rates of definite or probable stent thrombosis did not differ between groups (1·4% for E-ZES [predicted: 1·5%] vs 1·8% [predicted: 2·5%] for C-SES; hazard ratio [HR] 0·81, 95% CI 0·58-1·14, p=0·22). Dual antiplatelet therapy was used in 8402 (96%) patients at discharge, 7456 (88%) at 1 year, 3041 (37%) at 2 years, and 2364 (30%) at 3 years. No evidence of superiority of E-ZES compared with C-SES in definite or probable stent thrombosis rates was noted at 3 years. Time analysis suggests a difference in definite or probable stent thrombosis between groups is emerging over time, and a longer follow-up is therefore needed given the clinical relevance of stent thrombosis. Medtronic, Inc. Copyright © 2012 Elsevier Ltd. All rights reserved.

A randomized, placebo-controlled trial of repetitive spinal magnetic stimulation in lumbosacral spondylotic pain.

PubMed

Lo, Yew L; Fook-Chong, Stephanie; Huerto, Antonio P; George, Jane M

2011-07-01

Lumbar spondylosis is a degenerative disorder of the spine, whereby pain is a prominent feature that poses therapeutic challenges even after surgical intervention. There are no randomized, placebo-controlled studies utilizing repetitive spinal magnetic stimulation (SMS) in pain associated with lumbar spondylosis. In this study, we utilize SMS technique for patients with this condition in a pilot clinical trial. We randomized 20 patients into SMS treatment or placebo arms. All patients must have clinical and radiological evidence of lumbar spondylosis. Patients should present with pain in the lumbar region, localized or radiating down the lower limbs in a radicular distribution. SMS was delivered with a Medtronic R30 repetitive magnetic stimulator (Medtronic Corporation, Skovlunde, Denmark) connected to a C-B60 figure of eight coil capable of delivering a maximum output of 2 Tesla per pulse. The coil measured 90 mm in each wing and was centered over the surface landmark corresponding to the cauda equina region. The coil was placed flat over the back with the handle pointing cranially. Each patient on active treatment received 200 trains of five pulses delivered at 10 Hz, at an interval of 5 seconds between each train. "Sham" SMS was delivered with the coil angled vertically and one of the wing edges in contact with the stimulation point. All patients tolerated the procedure well and no side effects of SMS were reported. In the treatment arm, SMS had resulted in significant pain reduction immediately and at Day 4 after treatment (P < 0.05). In the placebo arm, however, no significant pain reduction was seen immediately and at Day 4 after SMS. SMS in the treatment arm had resulted in mean pain reduction of 62.3% postprocedure and 17.4% at Day 4. The placebo arm only achieved pain reduction of 6.1% postprocedure and 4.5% at Day 4. This is the first study to show that a single session of SMS resulted in significant improvement of pain associated with lumbar spondylosis in a randomized, double-blind, placebo-controlled setting. The novel findings support the potential of this technique for future studies pertaining to neuropathic pain. Wiley Periodicals, Inc.

Impact of polymer formulations on neointimal proliferation after zotarolimus-eluting stent with different polymers: insights from the RESOLUTE trial.

PubMed

Waseda, Katsuhisa; Ako, Junya; Yamasaki, Masao; Koizumi, Tomomi; Sakurai, Ryota; Hongo, Yoichiro; Koo, Bon-Kwon; Ormiston, John; Worthley, Stephen G; Whitbourn, Robert J; Walters, Darren L; Meredith, Ian T; Fitzgerald, Peter J; Honda, Yasuhiro

2011-06-01

Polymer formulation may affect the efficacy of drug-eluting stents. Resolute, Endeavor, and ZoMaxx are zotarolimus-eluting stents with different stent platforms and different polymer coatings and have been tested in clinical trials. The aim of this analysis was to compare the efficacy of zotarolimus-eluting stents with different polymers. Data were obtained from the first-in man trial or first randomized trials of each stent, The Clinical RESpOnse EvaLUation of the MedTronic Endeavor CR ABT-578 Eluting Coronary Stent System in De Novo Native Coronary Artery Lesions (RESOLUTE), Randomized Controlled Trial to Evaluate the Safety and Efficacy of the Medtronic AVE ABT-578 Eluting Driver Coronary Stent in De Novo Native Coronary Artery Lesions (ENDEAVOR II), and ZoMaxx I trials. Follow-up intravascular ultrasound analyses (8 to 9 months of follow-up) were possible in 353 patients (Resolute: 88, Endeavor: 98, ZoMaxx: 82, Driver: 85). Volume index (volume/stent length) was obtained for vessel, stent, lumen, peristent plaque, and neointima. Cross-sectional narrowing was defined as neointimal area divided by stent area (%). Neointima-free frame ratio was calculated as the number of frames without intravascular ultrasound-detectable neointima divided by the total number of frames within the stent. At baseline, vessel, lumen, and peristent plaque volume index were not significantly different among the 4 stent groups. At follow-up, percent neointimal obstruction was significantly lower in Resolute compared with Endeavor, ZoMaxx, and Driver (Resolute: 3.7±4.0, Endeavor: 17.5±10.1, ZoMaxx: 14.6±8.1, Driver: 29.4±17.2%; P<0.001). Greater maximum cross-sectional narrowing and higher neointima-free frame ratio, suggesting less neointimal coverage, were observed in Resolute compared with other stent groups. Multiple regression analysis confirmed that the biodurable polymer used in Resolute independently correlated with neointimal suppression among 3 zotarolimus-eluting stents. The different polymer formulations significantly affect the relative amount of neointima for zotarolimus-eluting stents. URL: http://www.clinicaltrials.gov. Unique identifier: NCT00248079.

Audiological comparison between two different clips prostheses in stapes surgery.

PubMed

Potena, M; Portmann, D; Guindi, S

2015-01-01

To compare audiometric results and complications of stapes surgery with two different types of piston prosthesis, the Portmann Clip Piston (Medtronic) (PCP) and the Soft Clip Piston (Kurz) (SCP). Study conducted on 64 patients who underwent primary stapedotomy from 2008 to 2011. We matched for each case of stapedotomy with the PCP (Medtronic Xomed Inc. Portmann Clip Piston Stainless Steel/Fluoroplastic) a case with the SCP (Heinz Kurz GmbH Medizintechnik Soft Piston Clip Titanium). Each group consisted of 32 patients, and patients in both groups were matched with respect to gender, age, bilateral or unilateral otosclerosis, otological symptoms (tinnitus, vertigo or dizziness), family history, operated side and the Portmann grading for otosclerosis. The length of the prosthesis used was reported. Post-operative complications such as tinnitus, vertigo, hearing loss and altered taste were documented. Each patient was subjected to a preoperative and postoperative audiogram (follow-up at the second month after the surgery). We used the Student test for statistical analysis. Statistical significance was set at < 0.01. None of the patients experienced a post-operative hearing loss and none required a later revision surgery. No statistically significant difference was found between the two populations regarding demographic data (age, sex, side, bilaterality, family history, stage and lenght of piston) and hearing level (> 0.01) in the air, bone conduction and air-bone gap (ABG). Postoperative complications did not result to be significantly different between the two groups. Also, both groups showed a significant improvement (< 0.01) in the post-operative air, bone conduction and air-bone gap. There was no statistically significant difference (> 0.01) between the post-operative hearing results (bone conduction, air conduction, air-bone gap) using the two pistons. The mean ABG improvement was respectively 16.63 dB in the SCP group and 20.59 dB in the PCP group. The titanium Soft clip piston (SCP) is a good alternative to the Portmann clip piston (PCP). Nevertheless there are some differences in the surgical fixing of these two pistons in the correct position.

Preoperative DTI and probabilistic tractography in an amputee with deep brain stimulation for lower limb stump pain.

PubMed

Owen, S L F; Heath, J; Kringelbach, M L; Stein, J F; Aziz, T Z

2007-10-01

This study aimed to find out whether preoperative diffusion tensor imaging (DTI) and probabilistic tractography could help with surgical planning for deep brain stimulation in the periaqueductal/periventricular grey area (PAG/PVG) in a patient with lower leg stump pain. A preoperative DTI was obtained from the patient, who then received DBS surgery in the PAG/PVG area with good pain relief. The postoperative MRI scan showing electrode placement was used to calculate four seed areas to represent the contacts on the Medtronic 3387 electrode. Probabilistic tractography was then performed from the pre-operative DTI image. Tracts were seen to connect to many areas within the pain network from the four different contacts. These initial findings suggest that preoperative DTI scanning and probabilistic tractography may be able to assist surgical planning in the future.

Comparison of Scientific Calipers and Computer-Enabled CT Review for the Measurement of Skull Base and Craniomaxillofacial Dimensions

PubMed Central

Citardi, Martin J.; Herrmann, Brian; Hollenbeak, Chris S.; Stack, Brendan C.; Cooper, Margaret; Bucholz, Richard D.

2001-01-01

Traditionally, cadaveric studies and plain-film cephalometrics provided information about craniomaxillofacial proportions and measurements; however, advances in computer technology now permit software-based review of computed tomography (CT)-based models. Distances between standardized anatomic points were measured on five dried human skulls with standard scientific calipers (Geneva Gauge, Albany, NY) and through computer workstation (StealthStation 2.6.4, Medtronic Surgical Navigation Technology, Louisville, CO) review of corresponding CT scans. Differences in measurements between the caliper and CT model were not statistically significant for each parameter. Measurements obtained by computer workstation CT review of the cranial skull base are an accurate representation of actual bony anatomy. Such information has important implications for surgical planning and clinical research. ImagesFigure 1Figure 2Figure 3 PMID:17167599

The Controversy Surrounding Bone Morphogenetic Proteins in the Spine: A Review of Current Research

PubMed Central

Hustedt, Joshua W.; Blizzard, Daniel J.

2014-01-01

Bone morphogenetic proteins have been in use in spinal surgery since 2002. These proteins are members of the TGF-beta superfamily and guide mesenchymal stem cells to differentiate into osteoblasts to form bone in targeted tissues. Since the first commercial BMP became available in 2002, a host of research has supported BMPs and they have been rapidly incorporated in spinal surgeries in the United States. However, recent controversy has arisen surrounding the ethical conduct of the research supporting the use of BMPs. Yale University Open Data Access (YODA) recently teamed up with Medtronic to offer a meta-analysis of the effectiveness of BMPs in spinal surgery. This review focuses on the history of BMPs and examines the YODA research to guide spine surgeons in their use of BMP in spinal surgery. PMID:25506287

Virtual evaluation of stent graft deployment: a validated modeling and simulation study.

PubMed

De Bock, S; Iannaccone, F; De Santis, G; De Beule, M; Van Loo, D; Devos, D; Vermassen, F; Segers, P; Verhegghe, B

2012-09-01

The presented study details the virtual deployment of a bifurcated stent graft (Medtronic Talent) in an Abdominal Aortic Aneurysm model, using the finite element method. The entire deployment procedure is modeled, with the stent graft being crimped and bent according to the vessel geometry, and subsequently released. The finite element results are validated in vitro with placement of the device in a silicone mock aneurysm, using high resolution CT scans to evaluate the result. The presented work confirms the capability of finite element computer simulations to predict the deformed configuration after endovascular aneurysm repair (EVAR). These simulations can be used to quantify mechanical parameters, such as neck dilations, radial forces and stresses in the device, that are difficult or impossible to obtain from medical imaging. Copyright © 2012 Elsevier Ltd. All rights reserved.

Computational Fluid Dynamics Analysis of Thrombosis Potential In Left Ventricular Assist Device Drainage Cannulae

PubMed Central

Fraser, Katharine H; Zhang, Tao; Taskin, M Ertan; Griffith, Bartley P; Wu, Zhongjun J

2010-01-01

Cannulation is necessary when blood is removed from the body, for example in hemodialysis, cardiopulmonary bypass, blood oxygenators, and ventricular assist devices. Artificial blood contacting surfaces are prone to thrombosis, especially in the presence of stagnant or recirculating flow. In this work, computational fluid dynamics was used to investigate the blood flow fields in three clinically available cannulae (Medtronic DLP 12, 16 and 24 F), used as drainage for pediatric circulatory support, and to calculate parameters which may be indicative of thrombosis potential. The results show that using the 24 F cannula below flow rates of about 0.75 l/min produces hemodynamic conditions which may increase the risk of blood clotting within the cannula. No reasons are indicated for not using the 12 or 16 F cannulae with flow rates between 0.25 and 3.0 l/min. PMID:20400890

[Recent advances of monitoring and glycaemia control during early postoperative period in patients after pancreas surgery].

PubMed

Lishova, E A; Nikoda, V V; Bondarenko, A V; Ragozin, A K; Skipenko, O G

2013-01-01

Recently new technologies of diagnostics and correction of carbohydrates metabolism disturbances are introduced in the ICU to improve the safety for patients during intensive care. 33 patients after pancreas surgery were included into the study 13 patients (39%) had underlying diabetes mellitus. Glucose level changes in the interstitial liquid of the subcutaneous fat during postoperative period were monitored by system of CGM Medtronic MiniMed Guardian RT, MiniMed Paradigm Real-time. Valid values of glucose were from 4.1 to 10.1 mmol/L. Episodes of glucose level increasing occurred in 94% of patients in postoperative period after pancreas surgery. Average level of glucose was within the limits of valid values. However in 64% of cases patients needed insulin therapy Used systems of continuous glucose monitoring in the ICU allow improving the safety for patients receiving artificial nutrition and intravenous insulin therapy.

A voltage-controlled capacitive discharge method for electrical activation of peripheral nerves.

PubMed

Rosellini, Will M; Yoo, Paul B; Engineer, Navzer; Armstrong, Scott; Weiner, Richard L; Burress, Chester; Cauller, Larry

2011-01-01

A voltage-controlled capacitive discharge (VCCD) method was investigated as an alternative to rectangular stimulus pulses currently used in peripheral nerve stimulation therapies.  In two anesthetized Gottingen mini pigs, the threshold (total charge per phase) for evoking a compound nerve action potential (CNAP) was compared between constant current (CC) and VCCD methods. Electrical pulses were applied to the tibial and posterior cutaneous femoralis nerves using standard and modified versions of the Medtronic 3778 Octad.  In contrast to CC stimulation, the combined application of VCCD pulses with a modified Octad resulted in a marked decrease (-73 ± 7.4%) in the stimulation threshold for evoking a CNAP. This was consistent for different myelinated fiber types and locations of stimulation.  The VCCD method provides a highly charge-efficient means of activating myelinated fibers that could potentially be used within a wireless peripheral nerve stimulator system. © 2011 International Neuromodulation Society.

Fifty years of pacemaker advancements.

PubMed

Steinhaus, David

2008-12-01

A 1957 power blackout in Minnesota prompted C. Walton Lillehei, MD, a pioneer in open heart surgery, to ask Earl Bakken, the co-founder of Medtronic, Inc., to create a battery-operated pacemaker for pediatric patients. That conversation led to the development of the first external battery-operated pacemaker. That first bulky device is far removed from the tiny implantable computers available to heart patients today. Now, the size of two silver dollars stacked on top of one another, a pacemaker is prescribed for a person whose heart beats too slowly or pauses irregularly. Slightly larger devices have more recently evolved from pacing and regulating the heartbeat to being able to provide therapeutic high voltage shocks when needed to stop runaway fast heart rates, recording heart activity, and other physiologic functions, even resynchronizing the heart's chambers-all while providing information on the patient's condition and device performance to the doctor remotely or in the office.

Lung Biopsies with the Curved Radial Reload™ Stapler.

PubMed

ElSaegh, Mohamed Moneer; Petsa, Afroditi; Dunning, Joel

2016-04-01

We describe our experience at the James Cook University Hospital (UK) in using the curved Radial Reload™ (RR) stapler (Medtronic, Dublin, Ireland) for lung wedge resections, which is an endoscopic stapler used mainly in endoscopic general surgery. A single center experience (James Cook University Hospital) for patients who had superficial or deep video-assisted thoracoscopic surgery (VATS) lung wedge resection, using the curved RR stapler. Seven patients had superficial or deep VATS lung biopsies-their ages ranged from 38 to 75 years, with a median length of hospital stay of two days (one to six days), and a mean length of hospital stay of 2.5 days. No complications were encountered. The curved RR stapler is effective in several situations and allows fewer firing of staplers. Our experience would suggest that they are as haemostatic and pneumostatic as the straight staplers and can be used effectively in both superficial and deep lung biopsies.

Intraoperative coronary grafts flow measurement using the TTFM flowmeter: results from a domestic sample.

PubMed

Succi, José Ernesto; Gerola, Luis Roberto; Succi, Guilherme de Menezes; Kim, Hyong Chun; Paredes, Jorge Edwin Morocho; Bufollo, Enio

2012-01-01

To evaluate intraoperative graft patency and identify grafts under risk of early occlusion. Fifty four patients were submitted to coronary artery bypass surgery and the graft flow was assessed by the Flowmeter (Medtronic Medistim), which utilizes the TTFM method. Three patients had left main disease and 48 had normal or mildly reduced left ventricular function. In hospital mortality was 3.7% (two patients), one for mesenteric thrombosis and one due to cardiogenic chock. Seventeen patients (34%) were submitted to off pump CABG. Arterial Graft flow measures ranged from 8 to 106 ml/min (average 31.14 ml/min), and venous grafts flow ranged from 9 to 149 ml/min (average 50.42 ml/min). Flowmeter use represents higher safety both for patients and surgeons. Even under legal aspects, the documentation provided by the device can avoid future questionings.

Utilization of a New Intracranial Support Catheter as an Intermediate Aspiration Catheter in the Treatment of Acute Ischemic Stroke: Technical Report on Initial Experience.

PubMed

Lozano, J Diego; Massari, Francesco; Howk, Mary C; de Macedo Rodrigues, Katyucia; Brooks, Christopher; Perras, Mary; Rex, David E; Wakhloo, Ajay K; Kühn, Anna Luisa; Puri, Ajit S

2016-05-21

The endovascular management of acute ischemic stroke (AIS) due to emergency large vessel occlusion (ELVO) has become the standard of care after the recent publication of landmark randomized, controlled trials. Mechanical thrombectomy, in addition to intravenous thrombolysis (within 4.5 hours when eligible), is now part of the algorithm of the standard of care when treating AIS in patients with ELVO in the anterior circulation up to six hours after symptom onset. A newly introduced device, the Arc™ intracranial support catheter (Medtronic, Irvine, USA), is specifically designed for the introduction of neurointerventional devices into the cerebral vasculature and facilitates the delivery of microcatheters into smaller, more distal intracranial vessels. This technical report describes the use of the Arc™ intracranial support catheter in the setting of AIS.

In Vitro Hydrodynamic Assessment of a New Transcatheter Heart Valve Concept (the TRISKELE).

PubMed

Rahmani, Benyamin; Tzamtzis, Spyros; Sheridan, Rose; Mullen, Michael J; Yap, John; Seifalian, Alexander M; Burriesci, Gaetano

2017-04-01

This study presents the in vitro hydrodynamic assessment of the TRISKELE, a new system suitable for transcatheter aortic valve implantation (TAVI), aiming to mitigate the procedural challenges experienced with current technologies. The TRISKELE valve comprises three polymeric leaflet and an adaptive sealing cuff, supported by a novel fully retrievable self-expanding nitinol wire frame. Valve prototypes were manufactured in three sizes of 23, 26, and 29 mm by automated dip-coating of a biostable polymer, and tested in a hydrodynamic bench setup in mock aortic roots of 21, 23, 25, and 27 mm annulus, and compared to two reference valves suitable for equivalent implantation ranges: Edwards SAPIEN XT and Medtronic CoreValve. The TRISKELE valves demonstrated a global hydrodynamic performance comparable or superior to the controls with significant reduction in paravalvular leakage. The TRISKELE valve exhibits enhanced anchoring and improved sealing. The valve is currently under preclinical investigation.

Utilization of a New Intracranial Support Catheter as an Intermediate Aspiration Catheter in the Treatment of Acute Ischemic Stroke: Technical Report on Initial Experience

PubMed Central

Lozano, J. Diego; Massari, Francesco; Howk, Mary C; de Macedo Rodrigues, Katyucia; Brooks, Christopher; Perras, Mary; Rex, David E; Wakhloo, Ajay K; Kühn, Anna Luisa

2016-01-01

The endovascular management of acute ischemic stroke (AIS) due to emergency large vessel occlusion (ELVO) has become the standard of care after the recent publication of landmark randomized, controlled trials. Mechanical thrombectomy, in addition to intravenous thrombolysis (within 4.5 hours when eligible), is now part of the algorithm of the standard of care when treating AIS in patients with ELVO in the anterior circulation up to six hours after symptom onset. A newly introduced device, the Arc™ intracranial support catheter (Medtronic, Irvine, USA), is specifically designed for the introduction of neurointerventional devices into the cerebral vasculature and facilitates the delivery of microcatheters into smaller, more distal intracranial vessels. This technical report describes the use of the Arc™ intracranial support catheter in the setting of AIS. PMID:27382525

Estimating the effective radiation dose imparted to patients by intraoperative cone-beam computed tomography in thoracolumbar spinal surgery.

PubMed

Lange, Jeffrey; Karellas, Andrew; Street, John; Eck, Jason C; Lapinsky, Anthony; Connolly, Patrick J; Dipaola, Christian P

2013-03-01

Observational. To estimate the radiation dose imparted to patients during typical thoracolumbar spinal surgical scenarios. Minimally invasive techniques continue to become more common in spine surgery. Computer-assisted navigation systems coupled with intraoperative cone-beam computed tomography (CT) represent one such method used to aid in instrumented spinal procedures. Some studies indicate that cone-beam CT technology delivers a relatively low dose of radiation to patients compared with other x-ray-based imaging modalities. The goal of this study was to estimate the radiation exposure to the patient imparted during typical posterior thoracolumbar instrumented spinal procedures, using intraoperative cone-beam CT and to place these values in the context of standard CT doses. Cone-beam CT scans were obtained using Medtronic O-arm (Medtronic, Minneapolis, MN). Thermoluminescence dosimeters were placed in a linear array on a foam-plastic thoracolumbar spine model centered above the radiation source for O-arm presets of lumbar scans for small or large patients. In-air dosimeter measurements were converted to skin surface measurements, using published conversion factors. Dose-length product was calculated from these values. Effective dose was estimated using published effective dose to dose-length product conversion factors. Calculated dosages for many full-length procedures using the small-patient setting fell within the range of published effective doses of abdominal CT scans (1-31 mSv). Calculated dosages for many full-length procedures using the large-patient setting fell within the range of published effective doses of abdominal CT scans when the number of scans did not exceed 3. We have demonstrated that single cone-beam CT scans and most full-length posterior instrumented spinal procedures using O-arm in standard mode would likely impart a radiation dose within the range of those imparted by a single standard CT scan of the abdomen. Radiation dose increases with patient size, and the radiation dose received by larger patients as a result of more than 3 O-arm scans in standard mode may exceed the dose received during standard CT of the abdomen. Understanding radiation imparted to patients by cone-beam CT is important for assessing risks and benefits of this technology, especially when spinal surgical procedures require multiple intraoperative scans.

Cost-Effectiveness of Transcatheter Aortic Valve Replacement With a Self-Expanding Prosthesis Versus Surgical Aortic Valve Replacement.

PubMed

Reynolds, Matthew R; Lei, Yang; Wang, Kaijun; Chinnakondepalli, Khaja; Vilain, Katherine A; Magnuson, Elizabeth A; Galper, Benjamin Z; Meduri, Christopher U; Arnold, Suzanne V; Baron, Suzanne J; Reardon, Michael J; Adams, David H; Popma, Jeffrey J; Cohen, David J

2016-01-05

Previous studies of the cost-effectiveness of transcatheter aortic valve replacement (TAVR) have been based primarily on a single balloon-expandable system. The goal of this study was to evaluate the cost-effectiveness of TAVR with a self-expanding prosthesis compared with surgical aortic valve replacement (SAVR) for patients with severe aortic stenosis and high surgical risk. We performed a formal economic analysis on the basis of individual, patient-level data from the CoreValve U.S. High Risk Pivotal Trial. Empirical data regarding survival and quality of life over 2 years, and medical resource use and hospital costs through 12 months were used to project life expectancy, quality-adjusted life expectancy, and lifetime medical costs in order to estimate the incremental cost-effectiveness of TAVR versus SAVR from a U.S. Relative to SAVR, TAVR reduced initial length of stay an average of 4.4 days, decreased the need for rehabilitation services at discharge, and resulted in superior 1-month quality of life. Index admission and projected lifetime costs were higher with TAVR than with SAVR (differences $11,260 and $17,849 per patient, respectively), whereas TAVR was projected to provide a lifetime gain of 0.32 quality-adjusted life-years ([QALY]; 0.41 LY) with 3% discounting. Lifetime incremental cost-effectiveness ratios were $55,090 per QALY gained and $43,114 per LY gained. Sensitivity analyses indicated that a reduction in the initial cost of TAVR by ∼$1,650 would lead to an incremental cost-effectiveness ratio <$50,000/QALY gained. In a high-risk clinical trial population, TAVR with a self-expanding prosthesis provided meaningful clinical benefits compared with SAVR, with incremental costs considered acceptable by current U.S. With expected modest reductions in the cost of index TAVR admissions, the value of TAVR compared with SAVR in this patient population would become high. (Safety and Efficacy Study of the Medtronic CoreValve System in the Treatment of Symptomatic Severe Aortic Stenosis in High Risk and Very High Risk Subjects Who Need Aortic Valve Replacement [Medtronic CoreValve U.S. Pivotal Trial]; NCT01240902). Copyright © 2016 American College of Cardiology Foundation. Published by Elsevier Inc. All rights reserved.

Editor's Choice - Late Open Surgical Conversion after Endovascular Abdominal Aortic Aneurysm Repair.

PubMed

Kansal, Vinay; Nagpal, Sudhir; Jetty, Prasad

2018-02-01

Late open surgical conversion following endovascular aneurysm repair (EVAR) may occur more frequently after performing EVAR in anatomy outside the instructions for use (IFU). This study reviews predictors and outcomes of late open surgical conversion for failed EVAR. This retrospective cohort study reviewed all EVARs performed at the Ottawa Hospital between January 1999 and May 2015. Open surgical conversions >1 month post EVAR were identified. Variables analysed included indication for conversion, pre-intervention AAA anatomy, endovascular device and configuration, operative technique, re-interventions, complications, and death. Of 1060 consecutive EVARs performed, 16 required late open surgical conversion. Endografts implanted were Medtronic Talent (n = 8, 50.0%), Medtronic Endurant (n = 3, 18.8%), Cook Zenith (n = 4, 25.0%), and Terumo Anaconda (n = 1, 6.2%). Eleven grafts were bifurcated (68.8%), five were aorto-uni-iliac (31.2%). The median time to open surgical conversion was 3.1 (IQR 1.0-5.2) years. There was no significant difference in pre-EVAR rupture status (1.4% elective, 2.1% ruptured, p = .54). Indications for conversion included: Type 1 endoleak with sac expansion (n = 4, 25.0%), Type 2 endoleak with expansion (n = 2, 12.5%), migration (n = 3, 18.8%), sac expansion without endoleak (n = 2, 12.5%), graft infection (n = 3, 18.8%), rupture (n = 2, 12.5%). Nine patients (56.2%) underwent stent graft explantation with in situ surgical graft reconstruction, seven had endograft preserving open surgical intervention. The 30 day mortality was 18.8% (n = 3, all of whom having had endograft preservation). Ten patients (62.5%) suffered major in hospital complications. One patient (6.5%) required post-conversion major surgical re-intervention. IFU adherence during initial EVAR was 43.8%, versus 79.0% (p < .01) among uncomplicated EVARs. Open surgical conversion following EVAR results in significant morbidity and mortality. IFU adherence of EVARs later requiring open surgical conversion is markedly low. More data are required to elucidate the impact of increasing liberalisation of EVAR outside of IFU. Copyright © 2017 European Society for Vascular Surgery. Published by Elsevier Ltd. All rights reserved.

Subcutaneous Stimulation as an Additional Therapy to Spinal Cord Stimulation for the Treatment of Low Back Pain and Leg Pain in Failed Back Surgery Syndrome: Four-Year Follow-Up.

PubMed

Hamm-Faber, Tanja E; Aukes, Hans; van Gorp, Eric-Jan; Gültuna, Ismail

2015-10-01

The objective of this study is to investigate the efficacy of long-term follow-up of subcutaneous stimulation (SubQ) as an additional therapy for patients with failed back surgery syndrome (FBSS) with chronic refractory pain, for whom spinal cord stimulation (SCS) alone was unsuccessful in treating low back pain. Prospective case series. FBSS patients with leg and/or low back pain whose conventional therapies had failed, received a combination of SCS (8-contact Octad lead, 3877-45 cm, Medtronic, Minneapolis, MN, USA) and/or SubQ (4-contact Quad Plus lead (s), 2888-28 cm, Medtronic). Initially, an Octad lead was placed in the epidural space for SCS for a trial stimulation to assess the suppression of leg and/or low back pain. Where SCS alone was insufficient in treating low back pain, lead(s) were placed superficially in the subcutaneous tissue of the lower back, exactly in the middle of the pain area. A pulse generator (Prime Advanced, 37702, Medtronic) was implanted if the patient reported more than 50% pain relief during the trial period. We investigated the long-term effect of neuromodulation on pain with the visual analog scale (VAS), and disability using the Quebec Pain Disability Scale. The results after 46 months are presented. Eleven patients, five men and six women (age 51 ± 8 years, mean ± SD) were included in the pilot study. In nine cases, SCS was used in combination with SubQ leads. Two patients received only SubQ leads. In one patient, the SCS + SubQ system was removed after nine months and these results were not taken into account for the analysis. Baseline scores for leg (N = 8) and low back pain (N = 10) were VASbl: 59 ± 15 and VASbl: 63 ± 14, respectively. The long-term follow-up period was 46 ± 4 months. SCS significantly reduced leg pain after 12 months (VAS12: 20 ± 11, p12 = 0.001) and 46 months (VAS46: 37 ± 17, p46 = 0.027). Similarly, SubQ significantly reduced back pain after 12 months(VAS12: 33 ± 16, p12 = 0.001) and 46 months (VAS46: 40 ± 21, p46 = 0.013). At 12 months, the Quebec Pain Disability Scale (QPDS) was 49 ± 12 and after 46 months, 53 ± 15. Both at 12 and 46 months, the QPDS values were statistically significantly better (p12 = 0.001, p46 = 0.04) compared with baseline values (QPDSbl: 61 ± 15). In one patient, the pain suppressive effect of SCS/SubQ had disappeared completely over time and the pain scores returned to prestimulation values. In four, patients back pain scores increased over time due to new issues (SI-joint problems, degenerative spine problems, disc problems, and hip pain) unrelated to FBSS and for which SCS/SubQ was not targeted or a reason for implantation at the start of the pilot study. This is the first prospective report on the combined use of SCS and SubQ with a follow-up period of four years. These data show that SCS and/or SubQ provide persistent long-term pain relief for leg and back pain in patients with FBSS. One should also take into account that new back/leg pain problems may evolve over time and increase the pain score which impact overall pain treatment. SCS combined with SubQ can be considered an effective long term treatment for low back pain in patients with FBSS for whom SCS alone is insufficient in alleviating their pain symptoms. © 2015 International Neuromodulation Society.

Nocturnal hypoglycaemia in type 1 diabetes--consequences and assessment.

PubMed

DeVries, J Hans; Wentholt, Iris M E; Masurel, Nathalie; Mantel, Itske; Poscia, Alessandro; Maran, Alberto; Heine, Robert J

2004-01-01

Hypoglycaemia is inevitable when striving for low HbA1c values. Nocturnal hypoglycaemia often occurs without symptoms, but results in diminished next day well-being and hypoglycaemia unawareness. Frequency of nocturnal hypoglycaemia was first assessed in research ward settings, but suffered from insufficient glucose sampling frequency. This may have resulted in overestimation of the duration of hypoglycaemic episodes. The advent of the first continuous glucose sensor, the needle-type MedtronicMiniMed Continuous Glucose Measurement System, revolutionized the assessment of glucose values. However, on scrutiny, the first version of this sensor showed a drift into the hypoglycaemic area and delayed recovery from hypoglycaemia. Using the microdialysis-based GlucoDay system, our group reported a lower frequency of nocturnal hypoglycaemia in type 1 diabetes patients using an insulin pump, than that expected from the existing literature. Today, more than 80 years after the introduction of insulin for the treatment of type 1 diabetes, the associated frequency of nocturnal hypoglycaemia still awaits its definitive assessment. Copyright 2004 John Wiley & Sons, Ltd.

Changes in turbulence with rotation of the omnicarbon prosthesis.

PubMed

Travis, Brandon R; Nyboe, Camilla; Christensen, Thomas D; Smerup, Morten; Johansen, Peter; Nygaard, Hans; Hasenkam, J Michael

2007-01-01

This study was performed to determine whether annular plane orientation of the Omnicarbon aortic valve influences forward flow turbulence. The Omnicarbon prostheses was modified to allow in situ manual rotation of the valve when implanted in the aortic position of eight 90 kg pigs. Pulsed Doppler ultrasound was used to acquire velocity measurements at 17 locations within the cross-sectional area of the ascending aorta. In each animal, 12 valve rotations were tested in this manner. Reynolds normal stresses were estimated from the velocity measurements. High Reynolds normal stresses were concentrated between left and posterior-right sides of the aortic wall for all orientations studied. No trends in mean or maximum Reynolds normal stresses with respect to valve rotation were consistent in the experiments. Unlike previous experiments with the Medtronic-Hall tilting disc valve, these experiments showed no notable changes in Reynolds normal stress with respect to orientation of the Omnicarbon valve. This suggests that the tendency of turbulent stresses to change with tilting disc valve orientation may be dependent on valve design.

Triple In Situ Antegrade Laser Fenestration of Aortic Stent-Graft Extension Using Fusion Imaging for Urgent Treatment of Symptomatic Abdominal Aneurysm with Type 1 Endoleak.

PubMed

Touma, Joseph; Kobeiter, Hicham; Majewski, Marek; Tacher, Vania; Desgranges, Pascal

2018-03-01

The present report describes the management of massive proximal type 1 endoleak with an enlarged symptomatic aneurysmal sac. Urgent treatment was performed using in situ laser fenestration of an aortic proximal extension facing renovisceral ostia. Image fusion was obtained intraoperatively. For each target vessel (superior mesenteric and two renal arteries), an Aptus HeliFX steerable sheath (Medtronic) inserted through femoral access was curved to face the vessel's ostium marker. A laser catheter (Spectranetics) was used to traverse the stent-graft and insert a 0.014" guidewire in the vessel. The fenestration was enlarged using a 2.5-mm-diameter cutting balloon, followed by a 4-mm-diameter balloon angioplasty and a V12 I Cast/Advanta covered stent implantation. Final angiogram demonstrated aneurysm exclusion and patent target vessels. The postoperative course and 7 months follow-up were uneventful. Level of evidence Level 4.

An industry update: the latest developments in therapeutic delivery.

PubMed

Steinbach, Oliver C

2017-03-01

The present industry update covers the period 1-31 January 2017, with information sourced from company press releases, regulatory and patent agencies as well as the scientific literature. With a new year come new resolutions, annual operation plans but also reports and outlooks for the years(s) to come. A number of the latter have been published in January forecasting various spaces in drug delivery (Market and Research). Also a number of financing deals were closed being fresh into the year such as Ossianix and Ocular Therapeutix and contract manufacturers will show their offerings at the 2017 MD&M West Medtech event (Lubrizol, Trelleborg). The US FDA released some new (draft) guidelines for combination products to regulate standards and disputes in this increasingly important field. Recent advances in artificial pancreas technology demonstrates that while the age of nanotechnology and gene therapy (Bluebird Bio) has arrived, implantable, closed-loop delivery systems (Medtronic) are just to pass successfully the clinic and come in reach of patients.

Transcatheter aortic valve implantation transapical: step by step.

PubMed

Walther, Thomas; Möllmann, Helge; van Linden, Arnaud; Kempfert, Jörg

2011-01-01

Transcatheter aortic valve implantation (T-AVI) has been introduced into clinical practice to treat high-risk elderly patients with aortic stenosis. T-AVI can be performed by using a retrograde transfemoral (TF), transsubclavian, transaortic, and/or antegrade transapical (TA) approach. For TA-AVI, CE mark approval was granted in 2008 for the Edwards SAPIEN (Edwards Lifesciences, Irvine, CA) prosthesis with the Ascendra delivery system and in 2010 for the second-generation Edwards SAPIEN XT prosthesis and the Ascendra II delivery system, with 23-mm and 26-mm valves. In 2011, CE mark approval has been granted for TA-AVI by using the SAPIEN XT 29-mm prosthesis. Several other devices from different companies (Jenavalve, Jena Valve Inc, Munich, Germany; Embracer, Medtronic Inc, Guilford, CT; Accurate, Symetis Inc, Geneva, Switzerland) have passed "first in man trials" successfully and are being evaluated within multicenter pivotal studies. In this article we will focus on specific aspects of the TA technique for AVI. Copyright © 2011 Elsevier Inc. All rights reserved.

Recent Advances in Transcatheter Aortic Valve Implantation: Novel Devices and Potential Shortcomings

PubMed Central

Blumenstein, J.; Liebetrau, C.; Linden, A. Van; Moellmann, H.; Walther, T.; Kempfert, J.

2013-01-01

During the past years transcatheter aortic valve implantation (TAVI) has evolved to a standard technique for the treatment of high risk patients suffering from severe aortic stenosis. Worldwide the number of TAVI procedures is increasing exponentially. In this context both the transapical antegrade (TA) and the transfemoral retrograde (TF) approach are predominantly used and can be considered as safe and reproducible access sites for TAVI interventions. As a new technology TAVI is in a constant progress regarding the development of new devices. While in the first years only the Edwards SAPIEN™ and the Medtronic CoreValve™ prostheses were commercial available, recently additional devices obtained CE-mark approval and others have entered initial clinical trials. In addition to enhance the treatment options in general, the main driving factor to further develop new device iterations is to solve the drawbacks of the current TAVI systems: paravalvular leaks, occurrence of AV-blocks and the lack of full repositionability. PMID:24313644

Navigation accuracy comparing non-covered frame and use of plastic sterile drapes to cover the reference frame in 3D acquisition.

PubMed

Corenman, Donald S; Strauch, Eric L; Dornan, Grant J; Otterstrom, Eric; Zalepa King, Lisa

2017-09-01

Advancements in surgical navigation technology coupled with 3-dimensional (3D) radiographic data have significantly enhanced the accuracy and efficiency of spinal fusion implant placement. Increased usage of such technology has led to rising concerns regarding maintenance of the sterile field, as makeshift drape systems are fraught with breaches thus presenting increased risk of surgical site infections (SSIs). A clinical need exists for a sterile draping solution with these techniques. Our objective was to quantify expected accuracy error associated with 2MM and 4MM thickness Sterile-Z Patient Drape ® using Medtronic O-Arm ® Surgical Imaging with StealthStation ® S7 ® Navigation System. Camera distance to reference frame was investigated for contribution to accuracy error. A testing jig was placed on the radiolucent table and the Medtronic passive reference frame was attached to jig. The StealthStation ® S7 ® navigation camera was placed at various distances from testing jig and the geometry error of reference frame was captured for three different drape configurations: no drape, 2MM drape and 4MM drape. The O-Arm ® gantry location and StealthStation ® S7 ® camera position was maintained and seven 3D acquisitions for each of drape configurations were measured. Data was analyzed by a two-factor analysis of variance (ANOVA) and Bonferroni comparisons were used to assess the independent effects of camera angle and drape on accuracy error. Median (and maximum) measurement accuracy error was higher for the 2MM than for the 4MM drape for each camera distance. The most extreme error observed (4.6 mm) occurred when using the 2MM and the 'far' camera distance. The 4MM drape was found to induce an accuracy error of 0.11 mm (95% confidence interval, 0.06-0.15; P<0.001) relative to the no drape testing, regardless of camera distance. Medium camera distance produced lower accuracy error than either the close (additional 0.08 mm error; 95% CI, 0-0.15; P=0.035) or far (additional 0.21mm error; 95% CI, 0.13-0.28; P<0.001) camera distances, regardless of whether a drape was used. In comparison to the 'no drape' condition, the accuracy error of 0.11 mm when using a 4MM film drape is minimal and clinically insignificant.

Programmable shunts and headphones: Are they safe together?

PubMed

Spader, Heather S; Ratanaprasatporn, Linda; Morrison, John F; Grossberg, Jonathan A; Cosgrove, G Rees

2015-10-01

Programmable shunts have a valuable role in the treatment of patients with hydrocephalus, but because a magnet is used to change valve settings, interactions with external magnets may reprogram these shunts. Previous studies have demonstrated the ability of magnetic toys and iPads to erroneously reprogram shunts. Headphones are even more ubiquitous, and they contain an electromagnet for sound projection that sits on the head very close to the shunt valve. This study is the first to look at the magnetic field emissions of headphones and their effect on reprogrammable shunt valves to ascertain whether headphones are safe for patients with these shunts to wear. In this in vitro study of the magnetic properties of headphones and their interactions with 3 different programmable shunts, the authors evaluated Apple earbuds, Beats by Dr. Dre, and Bose QuietComfort Acoustic Noise Cancelling headphones. Each headphone was tested for electromagnetic field emissions using a direct current gaussmeter. The following valves were evaluated: Codman Hakim programmable valve, Medtronic Strata II valve, and Aesculap proGAV. Each valve was tested at distances of 0 to 50 mm (in 5-mm increments) from each headphone. The exposure time at each distance was 1 minute, and 3 trials were performed to confirm results at each valve setting and distance. All 3 headphones generated magnetic fields greater than the respective shunt manufacturer's recommended strength of exposure, but these fields did not persist beyond 5 mm. By 2 cm, the fields levels were below 20 G, well below the Medtronic recommendation of 90 G and the Codman recommendation of 80 G. Because the mechanism for the proGAV is different, there is no recommended gauss level. There was no change in gauss-level emissions by the headphones with changes in frequency and amplitude. Both the Strata and Codman-Hakim valves were reprogrammed by direct contact (distance 0 mm) with the Bose headphones. When a rotation component was added, all 3 headphones reprogrammed the Strata and Codman-Hakim valves at 0 mm. At all distances above 0 mm, the headphones did not affect the shunts. The proGAV valve was not affected by headphones at any distance. Although all the headphones studied generated significant gauss fields at distances less than 5 mm, the programmable valve settings only changed at a distance of 0 mm (i.e., with direct contact). Given the subcutaneous location of the valve, the authors conclude that is highly unlikely that commercially available or customary headphones can contribute to the reprogramming of shunts.

Transcatheter valve-in-valve therapy using 6 different devices in 4 anatomic positions: Clinical outcomes and technical considerations.

PubMed

Conradi, Lenard; Silaschi, Miriam; Seiffert, Moritz; Lubos, Edith; Blankenberg, Stefan; Reichenspurner, Hermann; Schaefer, Ulrich; Treede, Hendrik

2015-12-01

Transcatheter valve-in-valve implantation (ViV) is emerging as a novel treatment option for patients with deteriorated bioprostheses. We report our cumulative experience using 6 types of transcatheter heart valves (THVs) in all anatomic positions. Seventy-five consecutive patients (74.1 ± 12.9 years, 50.7% male (38/75), logEuroSCORE I 26.2% ± 17.8%, STS-PROM 8.8% ± 7.4%) receiving ViV procedures from 2008 to 2014 were included for analysis. Data were prospectively gathered and retrospectively analyzed. ViV was performed in aortic (72.0%, 54/75), mitral (22.7%, 17/75), tricuspid (2.7%, 2/75), and pulmonary (2.7%, 2/75) positions. THVs used were Edwards SAPIEN (XT)/SAPIEN3 (52.0%, 39/75), Medtronic Core Valve/Core Valve Evolut(R) (34.7%, 26/75), St Jude Portico (4.0%, 3/75), Boston Scientific Lotus (4.0%, 3/75), Jena Valve (2.7%, 2/75), and Medtronic Engager (2.7%, 2/75). Interval from index procedure to ViV was 9.3 ± 4.9 years. Access was transapical in 53.3% (40/75), transfemoral (transarterial or transvenous) in 42.7% (32/75), transaortic in 2.7% (2/75), and transjugular in 1.3% (1/75). ViV was successful in 97.3% (73/75) with 2 patients requiring sequential THV implantation for initial malpositioning. Overall immediate procedural (≤72 hours) and all-cause 30-day mortality were 2.7% (2/75) and 8.0% (6/75). Corresponding values after aortic ViV were 1.9% (1/54) and 5.6% (3/54). No periprocedural strokes or cases of coronary obstruction occurred. Paravalvular leakage was less than or equal to mild in all cases. After aortic ViV, gradients were max/mean 34.1 ± 14.2/20.1 ± 7.1 mm Hg and effective orifice area (EOA) was 1.5 ± 1.4 cm(2). Corresponding values after mitral ViV were gradients max/mean 14.2 ± 8.2/4.7 ± 3.1 mm Hg and EOA 2.4 ± 0.9 cm(2). ViV can be performed in all anatomic positions with acceptable hemodynamic and clinical outcome in high-risk patients. Increasing importance of ViV can be anticipated considering growing use of surgical bioprostheses. Copyright © 2015 The American Association for Thoracic Surgery. Published by Elsevier Inc. All rights reserved.

Insulin pump therapy with automated insulin suspension in response to hypoglycemia: reduction in nocturnal hypoglycemia in those at greatest risk.

PubMed

Choudhary, Pratik; Shin, John; Wang, Yongyin; Evans, Mark L; Hammond, Peter J; Kerr, David; Shaw, James A M; Pickup, John C; Amiel, Stephanie A

2011-09-01

To evaluate a sensor-augmented insulin pump with a low glucose suspend (LGS) feature that automatically suspends basal insulin delivery for up to 2 h in response to sensor-detected hypoglycemia. The LGS feature of the Paradigm Veo insulin pump (Medtronic, Inc., Northridge, CA) was tested for 3 weeks in 31 adults with type 1 diabetes. There were 166 episodes of LGS: 66% of daytime LGS episodes were terminated within 10 min, and 20 episodes lasted the maximum 2 h. LGS use was associated with reduced nocturnal duration ≤2.2 mmol/L in those in the highest quartile of nocturnal hypoglycemia at baseline (median 46.2 vs. 1.8 min/day, P = 0.02 [LGS-OFF vs. LGS-ON]). Median sensor glucose was 3.9 mmol/L after 2-h LGS and 8.2 mmol/L at 2 h after basal restart. Use of an insulin pump with LGS was associated with reduced nocturnal hypoglycemia in those at greatest risk and was well accepted by patients.

Integrating bio-prosthetic valves in the Fontan operation - Novel treatment to control retrograde flow in caval veins

NASA Astrophysics Data System (ADS)

Vukicevic, Marija; Conover, Timothy; Zhou, Jian; Hsia, Tain-Yen; Figliola, Richard

2012-11-01

For a child born with only one functional heart ventricle, the sequence of palliative surgeries typically culminates in the Fontan operation. This procedure is usually successful initially, but leads to later complications, for reasons not fully understood. Examples are respiratory-dependent retrograde flows in the caval and hepatic veins, and increased pulmonary vascular resistance (PVR), hypothesized to be responsible for elevated pressure in the liver and disease of the liver and intestines. Here we study the parameters responsible for retrograde flows in the inferior vena cava (IVC) and hepatic vein (HV), and investigate two novel interventions to control retrograde flow: implanting either a Medtronic Contegra valved conduit or an Edwards lifescience pericardial aortic valve in the IVC or HV. We performed the experiments in a multi-scale, patient specific mock circuit, with normal and elevated PVR, towards the optimization of the Fontan circulation. The results show that both valves can significantly reduce retrograde flows in the veins, suggesting potential advantages in the treatment of the patients with congenital heart diseases. Fondation Leducq

Awake craniotomy using electromagnetic navigation technology without rigid pin fixation.

PubMed

Morsy, Ahmed A; Ng, Wai Hoe

2015-11-01

We report our institutional experience using an electromagnetic navigation system, without rigid head fixation, for awake craniotomy patients. The StealthStation® S7 AxiEM™ navigation system (Medtronic, Inc.) was used for this technique. Detailed preoperative clinical and neuropsychological evaluations, patient education and contrast-enhanced MRI (thickness 1.5mm) were performed for each patient. The AxiEM Mobile Emitter was typically placed in a holder, which was mounted to the operating room table, and a non-invasive patient tracker was used as the patient reference device. A monitored conscious sedation technique was used in all awake craniotomy patients, and the AxiEM Navigation Pointer was used for navigation during the procedure. This offers the same accuracy as optical navigation, but without head pin fixation or interference with intraoperative neurophysiological techniques and surgical instruments. The application of the electromagnetic neuronavigation technology without rigid head fixation during an awake craniotomy is accurate, and offers superior patient comfort. It is recommended as an effective adjunctive technique for the conduct of awake surgery. Copyright © 2015 Elsevier Ltd. All rights reserved.

On the added value of WUDAPT for Urban Climate Modelling

NASA Astrophysics Data System (ADS)

Brousse, Oscar; Martilli, Alberto; Mills, Gerald; Bechtel, Benjamin; Hammerberg, Kris; Demuzere, Matthias; Wouters, Hendrik; Van Lipzig, Nicole; Ren, Chao; Feddema, Johannes J.; Masson, Valéry; Ching, Jason

2017-04-01

Over half of the planet's population now live in cities and is expected to grow up to 65% by 2050 (United Nations, 2014), most of whom will actually occupy new emerging cities of the global South. Cities' impact on climate is known to be a key driver of environmental change (IPCC, 2014) and has been studied for decades now (Howard, 1875). Still very little is known about our cities' structure around the world, preventing urban climate simulations to be done and hence guidance to be provided for mitigation. Assessing the need to bridge the urban knowledge gap for urban climate modelling perspectives, the World Urban Database and Access Portal Tool - WUDAPT - project (Ching et al., 2015; Mills et al., 2015) developed an innovative technique to map cities globally rapidly and freely. The framework established by Bechtel and Daneke (2012) derives Local Climate Zones (Stewart and Oke, 2012) city maps out of LANDSAT 8 OLI-TIRS imagery (Bechtel et al., 2015) through a supervised classification by a Random Forest Classification algorithm (Breiman, 2001). The first attempt to implement Local Climate Zones (LCZ) out of the WUDAPT product within a major climate model was carried out by Brousse et al. (2016) over Madrid, Spain. This study proved the applicability of LCZs as an enhanced urban parameterization within the WRF model (Chen et al. 2011) employing the urban canopy model BEP-BEM (Martilli, 2002; Salamanca et al., 2010), using the averaged values of the morphological and physical parameters' ranges proposed by Stewart and Oke (2012). Other studies have now used the Local Climate Zones for urban climate modelling purposes (Alexander et al., 2016; Wouters et al. 2016; Hammerberg et al., 2017; Brousse et al., 2017) and demonstrated the added value of the WUDAPT dataset. As urban data accessibility is one of the major challenge for simulations in emerging countries, this presentation will show results of simulations using LCZs and the capacity of the WUDAPT framework to be of high relevancy in multiple regions of the world, such as Africa or Asia.

Sequential transcatheter aortic valve implantation due to valve dislodgement - a Portico valve implanted over a CoreValve bioprosthesis.

PubMed

Campante Teles, Rui; Costa, Cátia; Almeida, Manuel; Brito, João; Sondergaard, Lars; Neves, José P; Abecasis, João; M Gabriel, Henrique

2017-03-01

Transcatheter aortic valve implantation (TAVI) has become an important treatment in high surgical risk patients with severe aortic stenosis (AS), whose complications need to be managed promptly. The authors report the case of an 86-year-old woman presenting with severe symptomatic AS, rejected for surgery due to advanced age and comorbidities. The patient underwent a first TAVI, with implantation of a Medtronic CoreValve ® , which became dislodged and migrated to the ascending aorta. Due to the previous balloon valvuloplasty, the patient's AS became moderate, and her symptoms improved. After several months, she required another intervention, performed with a St. Jude Portico ® repositionable self-expanding transcatheter aortic valve. There was a good clinical response that was maintained at one-year follow-up. The use of a self-expanding transcatheter bioprosthesis with repositioning features is a solution in cases of valve dislocation to avoid suboptimal positioning of a second implant, especially when the two valves have to be positioned overlapping or partially overlapping each other. Copyright © 2017 Sociedade Portuguesa de Cardiologia. Publicado por Elsevier España, S.L.U. All rights reserved.

Assessing the direct effects of deep brain stimulation using embedded axon models

NASA Astrophysics Data System (ADS)

Sotiropoulos, Stamatios N.; Steinmetz, Peter N.

2007-06-01

To better understand the spatial extent of the direct effects of deep brain stimulation (DBS) on neurons, we implemented a geometrically realistic finite element electrical model incorporating anisotropic and inhomogenous conductivities. The model included the subthalamic nucleus (STN), substantia nigra (SN), zona incerta (ZI), fields of Forel H2 (FF), internal capsule (IC) and Medtronic 3387/3389 electrode. To quantify the effects of stimulation, we extended previous studies by using multi-compartment axon models with geometry and orientation consistent with anatomical features of the brain regions of interest. Simulation of axonal firing produced a map of relative changes in axonal activation. Voltage-controlled stimulation, with clinically typical parameters at the dorso-lateral STN, caused axon activation up to 4 mm from the target. This activation occurred within the FF, IC, SN and ZI with current intensities close to the average injected during DBS (3 mA). A sensitivity analysis of model parameters (fiber size, fiber orientation, degree of inhomogeneity, degree of anisotropy, electrode configuration) revealed that the FF and IC were consistently activated. Direct activation of axons outside the STN suggests that other brain regions may be involved in the beneficial effects of DBS when treating Parkinsonian symptoms.

Ventricular, but not atrial, M2-muscarinic receptors increase in the canine pacing-overdrive model of heart failure.

PubMed

Wilkinson, M; Giles, A; Armour, J A; Cardinal, R

1996-01-01

To investigate the effects of heart failure induced by chronic rapid ventricular pacing (six weeks) on canine atrial and ventricular muscarinic receptors. Dogs (n = 4) were fitted with a bipolar pacing electrode connected to a Medtronic pacemaker set at 240 stimuli/min. Pacing was maintained for six weeks. Tissue samples obtained from the left atrium and ventral wall of the left ventricle were frozen at -70 degrees C. Control tissue was obtained from normal dogs (n = 6) following anesthesia and thoracotomy. M2-muscarinic receptors were characterized and quantified in tissue micropunches using the hydrophilic ligand [3H] N-methyl-scopolamine (NMS). Cardiac tissue bound [3H] NMS with the specificity of an M2 subtype. Tachycardia-induced heart failure did not affect atrial muscarinic receptors but signify left ventricular myocytes (control 160.0 +/- 10.0 fmol/mg protein versus heart failure 245.0 +/- 25.0 fmol/mg protein; P < 0.01). Canine ventricular muscarinic receptors display a specificity for the M2 subtype. In contrast to previous work, tachycardia-induced heart failure was accompanied by an increase (+ 53%) in ventricular, but not atrial, M2 receptors compared with normal dogs.

Effects of non-nutritive (artificial vs natural) sweeteners on 24-h glucose profiles.

PubMed

Tey, S L; Salleh, N B; Henry, C J; Forde, C G

2017-09-01

Replacing nutritive sweetener with non-nutritive sweeteners (NNS) has the potential to improve glycaemic control. The objective of this study was to investigate the effects of consuming artificial NNS (that is, aspartame), natural NNS (that is, monk fruit and stevia), and sucrose-sweetened beverages on 24-h glucose profiles. Ten healthy males took part in this randomised, crossover study with the following four treatments: aspartame-, monk fruit-, stevia-, and sucrose- (65 g) sweetened beverages. Participants were asked to consume the test beverage as a preload mid-morning. Medtronic iPro2 continuous glucose monitoring system was used to measure mean 24-h glucose, incremental area under the curve (iAUC) and total area under the curve (AUC) for glucose, and 24-h glycaemic variability. Overall no significant differences were found in mean 24-h glucose, iAUC and total AUC for glucose, and 24-h glycaemic variability between the four test beverages. Twenty-four-hour glucose profiles did not differ between beverages sweetened with non-nutritive (artificial vs natural) and nutritive sweeteners. The simple exchange of a single serving of sucrose-sweetened beverage with NNS over a day appears to have minimal effect on 24-h glucose profiles in healthy males.

[Development and evaluation of a prosthetic valved conduit dilated by percutaneous approach: experimental study in the lamb].

PubMed

Boudjemline, Y; Laborde, F; Pineau, E; Mollet, A; Abadir, S; Bonhoeffer, P; Bonnet, D; Sidi, D

2006-05-01

This study was undertaken to develop a dilated valved conduit for reconstruction of the right ventricular outflow tract in the animal. The conduits were made by sewing a valved tube (Medtronic Inc) inside a vascular stent (Numed Inc). After preparation, they were inserted surgically in five lambs. The conduits were then dilated 6 weeks and 3 months after their implantation. Before sacrificing the animals at 3 months, a 22 mm valved stent was implanted percutaneously inside the surgical conduits. One animal died suddenly due to kinking of the conduit. Balloon dilatation was performed in the surviving animals. The first dilatation only had a modest impact on valvular function but it was much aggravated after the second dilatation. A valved stent was successfully inserted percutaneously. At sacrifice, all the conduits were completely engulfed in an intense fibrosis. In conclusion, a valved biological conduit for reconstruction of the right ventricular ejection tract has been developed and can be dilated sequentially to follow growth. The new product could have an important role to play in the management of congenital malformations involving the right ventricular outflow tract.

The neurophysiology of urinary retention in young women and its treatment by neuromodulation.

PubMed

Goodwin, R J; Swinn, M J; Fowler, C J

1998-01-01

Urinary retention occurring in young women as an isolated phenomenon was often thought to be psychogenic in origin. However, in 1988, Fowler et al. described a syndrome in young women in which urinary retention was the predominant feature and in which electromyography (EMG) of the striated urethral sphincter revealed a striking abnormality. This abnormality, it was postulated, would result in an inability of the sphincter to relax and retention would therefore result. Until recently there was no effective treatment for this disorder except management by clean intermittent self-catheterisation. However, preliminary results of neuromodulation using a Medtronic sacral nerve stimulator have been particularly promising in this group of patients. The response is often spectacular; a woman who has not passed urine per urethram for many months or years will frequently find that within a few hours of insertion of the percutaneous nerve evaluation (PNE) lead, she can void quite normally with little or no residual urine. The precise mechanism of action is yet to be defined, but measurements of the latency of anal sphincter contraction on S3 stimulation during PNE are so prolonged that they can only be the result of an afferent-mediated reflex.

Commercial Parts Technology Qualification Processes

NASA Technical Reports Server (NTRS)

Cooper, Mark S.

2013-01-01

Many high-reliability systems, including space systems, use selected commercial parts (including Plastic Encapsulated Microelectronics or PEMs) for unique functionality, small size, low weight, high mechanical shock resistance, and other factors. Predominantly this usage is subjected to certain 100% tests (typically called screens) and certain destructive tests usually (but not always) performed on the flight lot (typically called qualification tests). Frequently used approaches include those documented in EEE-INST-002 and JPL DocID62212 (which are sometimes modified by the particular aerospace space systems manufacturer). In this study, approaches from these documents and several space systems manufacturers are compared to approaches from a launch systems manufacturer (SpaceX), an implantable medical electronics manufacturer (Medtronics), and a high-reliability transport system process (automotive systems). In the conclusions section, these processes are outlined for all of these cases and presented in tabular form. Then some simple comparisons are made. In this introduction section, the PEM technology qualification process is described, as documented in EEE-INST-002 (written by the Goddard Space Flight Center, GSFC), as well as the somewhat modified approach employed at the Jet Propulsion Laboratory (JPL). Approaches used at several major NASA contractors are also described

Effect of cannula shape on aortic wall and flow turbulence: hydrodynamic study during extracorporeal circulation in mock thoracic aorta.

PubMed

Minakawa, Masahito; Fukuda, Ikuo; Yamazaki, Junichi; Fukui, Kozo; Yanaoka, Hideki; Inamura, Takao

2007-12-01

This study was designed to analyze flow pattern, velocity, and strain on the aortic wall of a glass aortic model during extracorporeal circulation, and to elucidate the characteristics of flow pattern in four aortic cannulas. Different patterns of large vortices and helical flow were made by each cannula. The high-velocity flow (0.6 m/s) was observed in end-hole cannula, causing high strain rate tensor (0.3~0.4 without unit) on the aortic arch. In dispersion cannula, a decreased strain rate tensor (less than 0.1) was found on the outer curvature of the aortic arch. In Soft-flow cannula (3M Cardiovascular, Ann Arbor, MI, USA), further decreased flow velocity (0.2 m/s) and strain (less than 0.2) were observed. In Select 3D cannula (Medtronic, Inc., Minneapolis, MN, USA), a high strain (0.4~0.5) was observed along the inner curvature of the aortic arch. In conclusion, end-hole cannula should not be used in atherosclerotic aorta. Particular attention should be paid both for selection of cannulas and cannulation site based on this result.

Temperature measurement on neurological pulse generators during MR scans

PubMed Central

Kainz, Wolfgang; Neubauer, Georg; Überbacher, Richard; Alesch, François; Chan, Dulciana Dias

2002-01-01

According to manufacturers of both magnetic resonance imaging (MRI) machines, and implantable neurological pulse generators (IPGs), MRI is contraindicated for patients with IPGs. A major argument for this restriction is the risk to induce heat in the leads due to the electromagnetic field, which could be dangerous for the surrounding brain parenchyma. The temperature change on the surface of the case of an ITREL-III (Medtronic Inc., Minneapolis, MN) and the lead tip during MRI was determined. An anatomical realistic and a cubic phantom, filled with phantom material mimicking human tissue, and a typical lead configuration were used to imitate a patient who carries an IPG for deep brain stimulation. The measurements were performed in a 1.5 T and a 3.0 T MRI. 2.1°C temperature increases at the lead tip uncovered the lead tip as the most critical part concerning heating problems in IPGs. Temperature increases in other locations were low compared to the one at the lead tip. The measured temperature increase of 2.1°C can not be considered as harmful to the patient. Comparison with the results of other studies revealed the avoidance of loops as a practical method to reduce heating during MRI procedures. PMID:12437766

Feasibility of tracked electrodes for use in epilepsy surgery

NASA Astrophysics Data System (ADS)

Holmes, David; Brinkmann, Benjamin; Hanson, Dennis; Worrell, Gregory; Robb, Richard; Holton, Leslie

2016-03-01

Subdural electrode recording is commonly used to evaluate intractable epilepsy. In order to accurately record electrical activity responsible for seizure, electrodes must be positioned precisely near targets of interest, often indicated preoperatively through imaging studies. To achieve accurate placement, a large craniotomy is used to expose the brain surface. With the intent of limiting the size and improving the location of craniotomy for electrode placement, we examined magnetic tracking for localization of electrode strips. Commercially available electrode strips were attached to specialized magnetic tracking sensors developed by Medtronic plc. In a rigid phantom we evaluated the strips to determine the accuracy of electrode placement on targets. We further conducted an animal study to evaluate the impact of magnetic field interference during data collection. The measured distance between the physical fiducial and lead coil of the electrode strip was 1.32 +/- 1.03mm in the phantom experiments. The tracking system induces a very strong signal in the electrodes in the Very Low Frequency, an International Telecommunication Union (ITU) designated frequency band, from 3 kHz to 30 kHz. The results of the animal experiment demonstrated both tracking feasibility and data collection.

In vitro assessment of six aspiration catheters using a distal protection filter.

PubMed

Fujimura, Tatsuhiro; Okamura, Takayuki; Ando, Miyuki; Uchida, Kousuke; Tone, Takashi; Yonezawa, Fumio; Yano, Masafumi

2016-01-01

We assessed performance of 6 aspiration catheters for distal embolization using a distal protection filter in an in vitro experiment. In acute myocardial infarction, a distal protection filter is used for lesions likely to induce a distal embolism. Which aspiration cathether is most effective when used with a distal protection filter remains still unclear. A 0.5-cm3 bolus of gelatin as a model of stagnant pools of coronary plaque debris was captured in the distal protection filter and aspirated by 6 aspiration catheters. We measured and compared the length of the suspended embolus matter. Among the 6 catheters evaluated, the use of the Export Advance catheter (Medtronic) resulted in significantly shorter lengths of the suspended embolus matter compared to the use of the TVAC II (Nipro), Thrombuster III SL (Kaneka), and Rebirth Pro (Goodman) catheters (p < 0.01). The residual embolus matter in all cases had drained distally to the distal protection filter when the filter was retrieved. The use of the Export Advance catheter showed better performance using a distal protection filter in this in vitro experiment, and its use might be more effective in preventing distal embolisms in combination with a distal protection filter.

The closing behavior of mechanical aortic heart valve prostheses.

PubMed

Lu, Po-Chien; Liu, Jia-Shing; Huang, Ren-Hong; Lo, Chi-Wen; Lai, Ho-Cheng; Hwang, Ned H C

2004-01-01

Mechanical artificial heart valves rely on reverse flow to close their leaflets. This mechanism creates regurgitation and water hammer effects that may form cavitations, damage blood cells, and cause thromboembolism. This study analyzes closing mechanisms of monoleaflet (Medtronic Hall 27), bileaflet (Carbo-Medics 27; St. Jude Medical 27; Duromedics 29), and trileaflet valves in a circulatory mock loop, including an aortic root with three sinuses. Downstream flow field velocity was measured via digital particle image velocimetry (DPIV). A high speed camera (PIVCAM 10-30 CCD video camera) tracked leaflet movement at 1000 frames/s. All valves open in 40-50 msec, but monoleaflet and bileaflet valves close in much less time (< 35 msec) than the trileaflet valve (>75 msec). During acceleration phase of systole, the monoleaflet forms a major and minor flow, the bileaflet has three jet flows, and the trileaflet produces a single central flow like physiologic valves. In deceleration phase, the aortic sinus vortices hinder monoleaflet and bileaflet valve closure until reverse flows and high negative transvalvular pressure push the leaflets rapidly for a hard closure. Conversely, the vortices help close the trileaflet valve more softly, probably causing less damage, lessening back flow, and providing a washing effect that may prevent thrombosis formation.

Endoscopic trans-nasal approach for biopsy of orbital tumours using image-guided neuro-navigation system.

PubMed

Sieskiewicz, A; Lyson, T; Mariak, Z; Rogowski, M

2008-05-01

Histopathological diagnosis of intraorbital tumours is of crucial value for planning further therapy. The aim of the study was to explore clinical utility of image-guided endoscopy for biopsy of orbital tumours. Trans-nasal endoscopic biopsy of intraorbital mass lesions was performed in 6 patients using a neuro-navigation system (Medtronic Stealth Station Treon plus). The CT and MRI 1 mm slice images were fused by the system in order to visualise both bony and soft tissue structures. The anatomic fiducial registration protocol was used during the procedure. All lesions were precisely localised and the biopsies could be taken from the representative part of the pathological mass. None of the patients developed aggravation of ocular symptoms after the procedure. The operative corridor as well as the size of orbital wall fenestration could be limited to a minimum. The accuracy of neuro-navigation remained high and stable during the entire procedure. The image-guided neuro-navigation system facilitated endoscopic localisation and biopsy of intraorbital tumours and contributed to the reduction of surgical trauma during the procedure. The technique was particularly useful in small, medially located, retrobulbar tumours and in unclear situations when the structure of the lesion resembled surrounding intraorbital tissue.

Recently patented transcatheter aortic valves in clinical trials.

PubMed

Neragi-Miandoab, Siyamek; Skripochnik, Edvard; Salemi, Arash; Girardi, Leonard

2013-12-01

The most widely used heart valve worldwide is the Edwards Sapien, which currently has 60% of the worldwide transcatheter aortic valve implantation (TAVI) market. The CoreValve is next in line in popularity, encompassing 35% of the worldwide TAVI market. Although these two valves dominate the TAVI market, a number of newer transcatheter valves have been introduced and others are in early clinical evaluation. The new valves are designed to reduce catheter delivery diameter, improve ease of positioning and sealing, and facilitate repositioning or removal. The most recent transcatheter valves for transapical use include Acurate TA (Symetis), Engager (Medtronic), and JenaValve the Portico (St Jude), Sadra Lotus Medical (Boston Scientific), and the Direct Flow Medical. These new inventions may introduce more effective treatment options for high-risk patients with severe aortic stenosis. Improvements in transcatheter valves and the developing variability among them may allow for more tailored approaches with respect to patient's anatomy, while giving operators the opportunity to choose devices they feel more comfortable with. Moreover, introducing new devices to the market will create a competitive environment among producers that will reduce high prices and expand availability. The present review article includes a discussion of recent patents related to Transcatheter Aortic Valves.

How does an inventor find an investor or partner? Raising funds to start a company.

PubMed

Mazzocchi, Rudy A

2017-05-01

Rudy Mazzocchi has over 25 years of senior executive management, technology and intellectual property development, and financing experience in the medical-technology/biotechnology industries. He serves currently as cofounder/chief executive officer of ELENZA, Inc, an ophthalmology company that has developed an electro-active, autofocusing, implantable lens; executive chairman of Establishment Labs; executive chairman of LAFORGE Optical; and executive chairman of OptiSTENT, Inc. He served previously as managing director of Accuitive Medical Ventures and The Innovation Factory; cofounder/chief executive officer of Image-Guided NEUROLOGICS, acquired by Medtronic in 2005; and founding chief executive officer of MICROVENA Corporation, which became "eV3," acquired by Covidien. He was formerly cofounder/director of Vascular Science, acquired by St Jude Medical in 1996, and cofounder/chairman of CytoGenesis, one of the first United States stem cell companies that was merged with BresaGen and listed on the Australian public exchange. He is the recipient of the Technology Leadership Award, the Businessman of the Year Award, the Ernst & Young Entrepreneur of the Year Award in Healthcare, and Global Entrepreneur of the Year Award. He has also authored more than 70 patents; 2 published, award-winning novels (medical thrillers); and a top-selling business book on entrepreneurism. Copyright © 2016 Elsevier Inc. All rights reserved.

Selective vibration sensing: a new concept for activity-sensing rate-responsive pacing.

PubMed

Lau, C P; Stott, J R; Toff, W D; Zetlein, M B; Ward, D E; Camm, A J

1988-09-01

A clinically available model of an activity-sensing, rate-responsive pacemaker (Activitrax, Medtronic) utilizes body vibration during exercise as an indicator of the need for a rate increase. Although having the advantage of rapid onset of rate response, this system lacks specificity and the rate response does not closely correlate with the level of exertion. In addition, this pacemaker is susceptible to the effects of extraneous vibration. In this study involving 20 normal subjects fitted with an external Activitrax pacemaker, the rate responses to a variety of exercises were studied and were compared with the corresponding sinus rates. The vibration generated at the level of the pacemaker was also measured by accelerometers in three axes. Only a fair correlation (r = 0.51) was achieved between the pacemaker rate and the sinus rate. The total root mean square value of acceleration in either the anteroposterior or the vertical axes was found to have a better correlation (r = 0.8). As the main accelerations during physical activities were in the lower frequency range (0.1-4 Hz), a low-pass filter was used to reduce the influence of extraneous vibration. Selective sensing of the acceleration level may be usefully implemented in an algorithm for activity pacing.

Safety of Onyx Transarterial Embolization of Skull Base Dural Arteriovenous Fistulas from Meningeal Branches of the External Carotids also Fed by Meningeal Branches of Internal Carotid or Vertebral Arteries.

PubMed

Abud, Thiago G; Houdart, Emmanuel; Saint-Maurice, Jean-Pierre; Abud, Daniel G; Baccin, Carlos E; Nguyen, Andrew D; Abdala, Nitamar

2017-08-11

To analyze the angiographic and clinical results of transarterial embolization with Onyx (Medtronic-Covidien, Irvine, CA) in dural arteriovenous fistulas (DAVFs) partially fed by arteries arising from the carotid siphon or the vertebral arteries. We isolated 40 DAVFs supplied by either the tentorial artery of the internal carotid artery (ICA) or the posterior meningeal artery of the vertebral artery. These DAVFs were embolized with Onyx through the middle meningeal artery or the occipital artery. We reviewed the occurrence of reflux into the arteries of carotid or vertebral origin. In all the cases, reflux occurred into the first millimeters of the DAVF arterial feeders arising from carotid or vertebral arteries but slowly enough to be controlled by interruption of Onyx injection. Reflux was always minimal and Onyx never reached the ostium of the arteries. No cerebral ischemic complications occurred in our series. The behavior of Onyx is clearly different from that of cyanoacrylate glue, resulting in superior control during injection. Reflux into arteries arising from the ICA or vertebral artery during DAVF treatment always carries a risk of unintentional non-target embolization of normal cerebral vasculature but Onyx appears to be safe in this situation.

Mechanisms of mechanical heart valve cavitation: investigation using a tilting disk valve model.

PubMed

He, Z; Xi, B; Zhu, K; Hwang, N H

2001-09-01

The induction of mechanical heart valve (MHV) cavitation was investigated using a 27 mm Medtronic Hall (MH27) tilting disk valve. The MH27 valve was mounted in the mitral position of a simulating pulse flow system, and stroboscopic lighting used to visualize cavitation bubbles on the occluder inflow surface at the instant of valve closure. MHV cavitation was monitored using a digital camera with 0.04 mm/pixel resolution sufficient to render the tiny bubbles clearly visible on the computer monitor screen. Cavitation on MH27 valve was classified as five types according to the time, site and shape of the cavitation bubbles. Valve cavitation occurred at the instant of occluder impact with the valve seat at closing. The impact motion was subdivided into three temporal phases: (i) squeezing flow; (ii) elastic collision; and (iii) leaflet rebound. MHV cavitation caused by vortices was found to be initiated by the squeezing jet and/or by the transvalvular leakage jets. By using a tension wave which swept across the occluder surface immediately upon elastic impact, nuclei in the vortex core were expanded to form cavitation bubbles. Analysis of the shape and location of the cavitation bubbles permitted a better understanding of MHV cavitation mechanisms, based on the fluid dynamics of jet vortex and tension wave propagations.

Temperature Control at DBS Electrodes using Heat Sink: Experimentally Validated FEM Model of DBS lead Architecture

PubMed Central

Elwassif, Maged M.; Datta, Abhishek; Rahman, Asif; Bikson, Marom

2012-01-01

There is a growing interest in the use of Deep Brain Stimulation for the treatment of medically refractory movement disorders and other neurological and psychiatric conditions. The extent of temperature increases around DBS electrodes during normal operation (joule heating and increased metabolic activity) or coupling with an external source (e.g. MRI) remains poorly understood and methods to mitigate temperature increases are being actively investigated. We developed a heat transfer finite element method simulation of DBS incorporating the realistic architecture of Medtronic 3389 leads. The temperature changes were analyzed considering different electrode configurations, stimulation protocols, and tissue properties. The heat-transfer model results were then validated using micro-thermocouple measurements during DBS lead stimulation in a saline bath. FEM results indicate that lead design (materials and geometry) may have a central role in controlling temperature rise by conducting heat. We show how modifying lead design can effectively control temperature increases. The robustness of this heat-sink approach over complimentary heat-mitigation technologies follows from several features: 1) it is insensitive to the mechanisms of heating (e.g. nature of magnetic coupling); 2) does not interfere with device efficacy; and 3) can be practically implemented in a broad range of implanted devices without modifying the normal device operations or the implant procedure. PMID:22764359

[Feasibility of auditory cortical stimulation for the treatment of tinnitus. Three case reports].

PubMed

Litré, C-F; Giersky, F; Theret, E; Leveque, M; Peruzzi, P; Rousseaux, P

2010-08-01

Tinnitus is a public health issue in France. Around 1 % of the population is affected and 30,000 people are handicapped in their daily life. The treatments available for disabling tinnitus have until now been disappointing. We report our experience on the treatment of these patients in neurosurgery. Between 2006 and 2008, transcranial magnetic stimulation (rTMS) was performed following several supraliminal and subliminal protocols in 16 patients whose mean age was 47 years (range, 35-71). All patients underwent anatomical and functional MRI of the auditory cortex before and 18 h after rTMS, to straddle the primary and secondary auditory cortices. All patients underwent audiometric testing by an ENT physician. Nine patients responded with rTMS. After these investigations, two quadrapolar electrodes (Resume), connected to a stimulating device implanted under the skin (Synergy, from Medtronic), were extradurally implanted in three patients. The electrodes were placed between the primary and secondary auditory cortices. The mean follow-up was 25 months and significant improvement was found in these patients. The feasibility of cortical stimulation in symptomatic treatment of tinnitus was demonstrated by this preparatory work. The intermediate- and long-term therapeutic effects remain to be evaluated. Copyright (c) 2010 Elsevier Masson SAS. All rights reserved.

Assessment of hypoglycaemia awareness using continuous glucose monitoring.

PubMed

Kubiak, T; Hermanns, N; Schreckling, H J; Kulzer, B; Haak, T

2004-05-01

To investigate the possibility of assessing hypoglycaemia awareness in patients with Type 1 diabetes using continuous glucose monitoring. Twenty patients with Type 1 diabetes were investigated. Ten patients with Type 1 diabetes and strongly impaired hypoglycaemia awareness were compared with 10 patients with intact hypoglycaemia awareness regarding quality of hypoglycaemia perception (number of undetected hypoglycaemic episodes per 24 h, glucose level < 3.3 mmol/l). Hypoglycaemia detection was assessed using the event function of the Continuous Glucose Monitoring System (CGMS; Medtronic MiniMed, Northridge, CA, USA). Patients were instructed to enter an event upon suspecting being hypoglycaemic. Satisfactory CGMS performance could be achieved [mean r = 0.893 between calibration measurements and CGMS data, mean absolute difference (MAD) = 20.6%], although artefacts were observable and had to be controlled. Hypoglycaemia unaware patients showed a significantly higher total number of hypoglycaemic episodes (P < 0.05), number of undetected hypoglycaemic episodes (P < 0.01), and mean glucose levels (P < 0.05). Even in aware patients, undetected hypoglycaemia was observable. No significant differences regarding occurrence of nocturnal hypoglycaemia were observable. The possibility of direct assessment of hypoglycaemia awareness using continuous glucose monitoring was demonstrated. Its application in clinical practice could be of use for assessing hypoglycaemia perception and evaluating the impact of treatment changes on hypoglycaemia awareness.

Advances in drug eluting stents – focus on the Endeavor® zotarolimus stent

PubMed Central

Bridges, Jonathan; Cutlip, Donald

2009-01-01

Coronary artery disease remains one of the leading causes of death in the United States. Over the last 30 years, the development of coronary artery angioplasty and stenting has drastically reduced mortality during acute coronary syndromes while also reducing symptoms of chronic coronary artery disease. Unfortunately, the placement of stents in a coronary artery can be complicated by in-stent thrombosis or restenosis. In 2003–2004, a new generation of stents was introduced to the market with the goal of reducing the rate of restenosis. These stents, called drug eluting stents (DES), are coated with a pharmacological agent designed to reduce the neointimal hyperplasia associated with restenosis. Within a year, approximately 80% of all percutaneous coronary interventions performed within the US involved placement of a DES. In 2006, a controversy arose about the possibility of a statistically significant increased risk of acute stent thrombosis associated with DES especially when used for an “off label” indication. This risk was attributed to delayed endothelization. This controversy has led to a reduction in the use of DES along with longer use of dual platelet inhibition with aspirin and clopidogrel. Recently Medtronic introduced a new DES to the market called the Endeavor® stent – a zotarolimus eluting stent. PMID:22915908

Great Institutions in Cardiothoracic Surgery: The University of Minnesota.

PubMed

Huddleston, Stephen J; Shumway, Sara

2016-01-01

With the loyal support of the chair of Surgery, Dr. Owen H. Wangensteen, the University of Minnesota cardiac surgery program led the way at the dawn of cardiac surgery when Dr F. John Lewis performed the first open heart surgery in the world using hypothermia while repairing an atrial septal defect on September 2, 1952. Soon after, Dr C. Walt Lillehei performed the first repair of a ventriculoseptal defect in the world using cross-circulation on March 26, 1954. Collaborating with Dr Richard DeWall in 1955, they developed the DeWall-Lillehei bubble oxygentor which was used at the University of Minnesota and many other centers worldwide for years to come, making open heart surgery safe and tractable. Dr Vincent Gott, a resident working in the laboratory of Lillehei, developed a method to treat complete heart block using ventricular pacing with a Grass physiological stimulator, and this led to a collaboration with Earl Bakken, founder of the Medtronic Corporation, to develop a temporary pacemaker. The program was fertile ground for many notable trainees, including Dr Norman Shumway, the "Father of Heart Transplant", and Dr Christiaan Barnard who performed the first heart transplant in the world. The collegial and forward thinking nature of the cardiac surgery program continues in the current training program today. Copyright © 2016 Elsevier Inc. All rights reserved.

"Low-field" intraoperative MRI: a new scenario, a new adaptation.

PubMed

Iturri-Clavero, F; Galbarriatu-Gutierrez, L; Gonzalez-Uriarte, A; Tamayo-Medel, G; de Orte, K; Martinez-Ruiz, A; Castellon-Larios, K; Bergese, S D

2016-11-01

To describe the adaptation of Cruces University Hospital to the use of intraoperative magnetic resonance imaging (ioMRI), and how the acquisition and use of this technology would impact the day-to-day running of the neurosurgical suite. With the approval of the ethics committee, an observational, prospective study was performed from June 2012 to April 2014, which included 109 neurosurgical procedures with the assistance of ioMRI. These were performed using the Polestar N-30 system (PSN30; Medtronic Navigation, Louisville, CO), which was integrated into the operating room. A total of 159 procedures were included: 109 cranial surgeries assisted with ioMRI and 50 control cases (no ioMRI use). There were no statistical significant differences when anaesthetic time (p=0.587) and surgical time (p=0.792) were compared; however, an important difference was shown in duration of patient positioning (p<0.0009) and total duration of the procedure (p<0.0009) between both groups. The introduction of ioMRI is necessary for most neurosurgical suites; however, a few things need to be taken into consideration when adapting to it. Increase procedure time, the use of specific MRI-safe devices, as well as a checklist for each patient to minimise risks, should be taken into consideration. Published by Elsevier Ltd.

Shielded battery syndrome: a new hardware complication of deep brain stimulation.

PubMed

Chelvarajah, Ramesh; Lumsden, Daniel; Kaminska, Margaret; Samuel, Michael; Hulse, Natasha; Selway, Richard P; Lin, Jean-Pierre; Ashkan, Keyoumars

2012-01-01

Deep brain stimulation hardware is constantly advancing. The last few years have seen the introduction of rechargeable cell technology into the implanted pulse generator design, allowing for longer battery life and fewer replacement operations. The Medtronic® system requires an additional pocket adaptor when revising a non-rechargeable battery such as their Kinetra® to their rechargeable Activa® RC. This additional hardware item can, if it migrates superficially, become an impediment to the recharging of the battery and negate the intended technological advance. To report the emergence of the 'shielded battery syndrome', which has not been previously described. We reviewed our deep brain stimulation database to identify cases of recharging difficulties reported by patients with Activa RC implanted pulse generators. Two cases of shielded battery syndrome were identified. The first required surgery to reposition the adaptor to the deep aspect of the subcutaneous pocket. In the second case, it was possible to perform external manual manipulation to restore the adaptor to its original position deep to the battery. We describe strategies to minimise the occurrence of the shielded battery syndrome and advise vigilance in all patients who experience difficulty with recharging after replacement surgery of this type for the implanted pulse generator. Copyright © 2012 S. Karger AG, Basel.

Remaining useful life assessment of lithium-ion batteries in implantable medical devices

NASA Astrophysics Data System (ADS)

Hu, Chao; Ye, Hui; Jain, Gaurav; Schmidt, Craig

2018-01-01

This paper presents a prognostic study on lithium-ion batteries in implantable medical devices, in which a hybrid data-driven/model-based method is employed for remaining useful life assessment. The method is developed on and evaluated against data from two sets of lithium-ion prismatic cells used in implantable applications exhibiting distinct fade performance: 1) eight cells from Medtronic, PLC whose rates of capacity fade appear to be stable and gradually decrease over a 10-year test duration; and 2) eight cells from Manufacturer X whose rates appear to be greater and show sharp increase after some period over a 1.8-year test duration. The hybrid method enables online prediction of remaining useful life for predictive maintenance/control. It consists of two modules: 1) a sparse Bayesian learning module (data-driven) for inferring capacity from charge-related features; and 2) a recursive Bayesian filtering module (model-based) for updating empirical capacity fade models and predicting remaining useful life. A generic particle filter is adopted to implement recursive Bayesian filtering for the cells from the first set, whose capacity fade behavior can be represented by a single fade model; a multiple model particle filter with fixed-lag smoothing is proposed for the cells from the second data set, whose capacity fade behavior switches between multiple fade models.

Influence of aortic neck characteristics on successful aortic wall penetration of EndoAnchors in therapeutic use during endovascular aneurysm repair.

PubMed

Goudeketting, Seline R; van Noort, Kim; Ouriel, Kenneth; Jordan, William D; Panneton, Jean M; Slump, Cornelis H; de Vries, Jean-Paul P M

2018-04-21

This study sought to quantify EndoAnchor (Medtronic Vascular, Santa Rosa, Calif) penetration into the aortic wall in patients undergoing endovascular abdominal aortic aneurysm repair and to assess predictors of successful penetration and its relationship to postprocedural type IA endoleak. A subset of patients from the Aneurysm Treatment Using the Heli-FX Aortic Securement System Global Registry (ANCHOR) were included if they met the following criteria: the indication for EndoAnchor use was to treat a type IA endoleak, and postprocedure contrast-enhanced computed tomography (CT) scans of sufficient quality were available for core laboratory review. Patients undergoing implantation of cuffs or stents during the EndoAnchor implantation procedure were excluded. Baseline anatomic characteristics were recorded. The cohort was divided into patients with and without persistent type IA endoleaks at the first postoperative CT scan. Penetration of each EndoAnchor measured on this CT scan was defined as good penetration when the EndoAnchor penetrated ≥2 mm into the aortic wall, borderline penetration when EndoAnchor penetration was <2 mm or a gap remained between the endograft and aortic wall, or no penetration when the EndoAnchor did not penetrate into the aortic wall. Differences between the groups were analyzed with the Mann-Whitney U test or Fisher exact test. Multivariate analyses were performed to identify independent predictors of EndoAnchor penetration, and procedural success was defined by absence of type IA endoleak. Eighty-six patients of the primary (n = 61 [71%]) and revision (n = 25 [29%]) arms of the ANCHOR registry were included. There were 53 (62%) without and 33 (38%) with persistent type IA endoleaks on the first postprocedural CT scan. The median number of EndoAnchors with good penetration was significantly greater in the cohort without endoleaks, 4 (interquartile range, 3-5) vs 3 (interquartile range, 1.5-4), respectively (P = .002). A multivariate model for EndoAnchor penetration identified use of a Medtronic Endurant endograft as a factor associated with good penetration (P = .001), whereas poor penetration was associated with a larger aortic neck diameter 10 mm distal to the lowest renal artery (P < .001) and greater proximal neck calcium thickness (P = .004). EndoAnchor penetration was the only variable that attained significance (P < .001) in the multivariate model for successful treatment of a type IA endoleak. Adequate EndoAnchor penetration into the aortic wall is less likely when the aortic neck diameter is large or when the neck contains significant mural calcium. No penetration of the EndoAnchor was the only factor predictive of postprocedural type IA endoleak. This study stresses the importance of careful selection of patients based on preoperative assessment of the infrarenal neck on CT angiography and emphasizes careful deployment of EndoAnchors into the aortic wall to improve successful treatment of type IA endoleaks. Copyright © 2018 Society for Vascular Surgery. Published by Elsevier Inc. All rights reserved.

Remote monitoring of implantable cardioverter-defibrillators. Problems and implications using a telemonitoring system.

PubMed

Siebermair, J; Clauss, S; Martens, E; Schuessler, F; Oversohl, N; Haserueck, N; Estner, H L; Kääb, S; Wakili, R

2015-04-01

The rising number of implantable devices has led to an increase in device-related workload, e.g., regular interrogation follow-up visits. Telemonitoring systems for implantable cardioverter-defibrillators (ICDs) seem to be a promising tool for reducing workload and costs, and they have the potential of optimizing patient care. However, issues such as practical functionality of ICD telemonitoring in daily routine may affect its broad implementation. The objective of this study was to evaluate potential problems during the implementation of a telemonitoring system, Medtronic CareLink™ (CL™) with respect to the installation and data transmission process. A total of 159 patients with ICDs who were equipped with the CL™ system were evaluated and followed up for 16 months regarding the success rate of the first data transmission via the telemonitoring system. In this cohort, a high rate of nontransmission of 23.9 % was observed after the 16-month follow-up. A detailed interview of these patients (no transmission) revealed that the main reasons for failed transmissions were due to the patients' loss of interest in the concept (approximately 50 %) as well as technical problems (approximately 25 %) with setting up the system. These results indicate that telemonitoring systems bear potential problems and that the evaluation of patient motivation and technical support options seems to play an important role in establishing the functionality of these systems.

Accuracy of Continuous Glucose Monitoring before, during, and after Aerobic and Anaerobic Exercise in Patients with Type 1 Diabetes Mellitus

PubMed Central

Bertachi, Arthur; Quirós, Carmen; Giménez, Marga; Conget, Ignacio; Bondia, Jorge

2018-01-01

Continuous glucose monitoring (CGM) plays an important role in treatment decisions for patients with type 1 diabetes under conventional or closed-loop therapy. Physical activity represents a great challenge for diabetes management as well as for CGM systems. In this work, the accuracy of CGM in the context of exercise is addressed. Six adults performed aerobic and anaerobic exercise sessions and used two Medtronic Paradigm Enlite-2 sensors under closed-loop therapy. CGM readings were compared with plasma glucose during different periods: one hour before exercise, during exercise, and four hours after the end of exercise. In aerobic sessions, the median absolute relative difference (MARD) increased from 9.5% before the beginning of exercise to 16.5% during exercise (p < 0.001), and then decreased to 9.3% in the first hour after the end of exercise (p < 0.001). For the anaerobic sessions, the MARD before exercise was 15.5% and increased without statistical significance to 16.8% during exercise realisation (p = 0.993), and then decreased to 12.7% in the first hour after the cessation of anaerobic activities (p = 0.095). Results indicate that CGM might present lower accuracy during aerobic exercise, but return to regular operation a few hours after exercise cessation. No significant impact for anaerobic exercise was found. PMID:29522429

Atrial therapies reduce atrial arrhythmia burden in defibrillator patients.

PubMed

Friedman, P A; Dijkman, B; Warman, E N; Xia, H A; Mehra, R; Stanton, M S; Hammill, S C

2001-08-28

Approximately 25% of patients who receive an implantable cardioverter-defibrillator (ICD) to treat ventricular tachyarrhythmias have documented atrial tachyarrhythmias before implantation. This study assessed the ability of device-based prevention and termination therapies to reduce the burden of spontaneous atrial tachyarrhythmias. Patients with a standard indication for the implantation of an ICD and 2 episodes of atrial tachyarrhythmias in the preceding year received a dual-chamber ICD (Medtronic 7250 Jewel AF) that uses pacing and shock therapies for prevention and/or termination of atrial tachyarrhythmias. In a multicenter trial, patients were randomized to 3-month periods with atrial therapies "on" or "off" and subsequently crossed over. Analysis was performed on the 52 of 269 patients who had episodes of atrial tachyarrhythmia and had >/=30 days of follow-up with atrial therapies on and off. The atrial therapies resulted in a reduction of atrial tachyarrhythmia burden from a mean of 58.5 to 7.8 h/mo. A paired analysis (Wilcoxon signed-rank test) showed that the median difference in burden (1.1 h/mo) was highly significant (P=0.007). When the subgroup of 41 patients treated only with atrial pacing therapies was analyzed, the reduction in burden persisted (P=0.01). In this study, patients with a standard ICD indication and atrial tachyarrhythmias had a significant reduction in atrial tachyarrhythmia burden with use of atrial pacing and shock therapies.

[Clinical experiences with four newly developed, surface modified stimulation electrodes].

PubMed

Winter, U J; Fritsch, J; Liebing, J; Höpp, H W; Hilger, H H

1993-05-01

Newly developed pacing electrodes with so-called porous surfaces promise a significantly improved post-operative pacing and sensing threshold. We therefore investigated four newly developed leads (ELA-PMCF-860 n = 10; Biotronik-60/4-DNP n = 10, CPI-4010 n = 10, Intermedics-421-03-Biopore n = 6) connected to two different pacing devices (Intermedics NOVA II, Medtronic PASYS) in 36 patients (18 men, 18 women, age: 69.7 +/- 9.8 years) suffering from symptomatic bradycardia. The individual electrode maturation process was investigated by means of repeated measurements of pacing threshold, electrode impedance in acute, subacute, and chronic phase, as well as energy consumption and sensing behavior in the chronic phase. However, with the exception of the 4010, the investigated leads showed largely varying values of the pacing threshold with individual peaks occurring from the second up to the 13th week. All leads had nearly similar chronic pacing thresholds (PMCF 0.13 +/- 0.07; DNP 0.25 +/- 0.18; Biopore 0.15 +/- 0.05; 4010 0.14 +/- 0.05 ms). Impedance measurements revealed higher, but not significantly different values for the DNP (PMCF 582 +/- 112, DNP 755 +/- 88, Biopore 650 +/- 15, 4010 718 +/- 104 Ohm). Despite differing values for pacing threshold and impedance, the energy consumption in the chronic phase during threshold-adapted, but secure stimulation (3 * impulse-width at pacing threshold) were comparable.

Holding Area LINQ Trial (HALT).

PubMed

Lee, John J; Weitz, Daniel; Anand, Rishi

Recent studies have shown that insertable cardiac monitors (ICMs) can be implanted out of the traditional hospital setting and efforts are being made to explore the feasibility of implanting these devices in a specific standardized location other than the operating room or a cardiac catherization/electrophysiology lab. This was a prospective, non-randomized, single center post-market clinical trial designed to occur in the holding area of a hospital operating room or cardiac catheterization/electrophysiology laboratory. The Medtronic Reveal LINQ ICM was implanted and patients were followed for 90 days post implant. This study was designed to observe any procedure related adverse events stemming from the holding area implantation. Twenty patients were implanted at our hospital in a holding room not traditionally associated with the electrophysiology/cardiac/operatory labs. One patient was lost to the 90-day follow up. In one case, ICM implantation led to diagnosis requiring removal of ICM before the 90 day follow up and insertion of a biventricular implantable cardioverter defibrillator (ICD). In the remaining 18 patients, there were no serious complications such as minor skin infections, systemic infections or procedure-related adverse events requiring device explant. When following a standardized protocol with attention to sterile technique, it is feasible to implant ICMs in a holding area with no procedure related adverse events (AE). Copyright © 2017 Indian Heart Rhythm Society. Production and hosting by Elsevier B.V. All rights reserved.

Temperature control at DBS electrodes using a heat sink: experimentally validated FEM model of DBS lead architecture.

PubMed

Elwassif, Maged M; Datta, Abhishek; Rahman, Asif; Bikson, Marom

2012-08-01

There is a growing interest in the use of deep brain stimulation (DBS) for the treatment of medically refractory movement disorders and other neurological and psychiatric conditions. The extent of temperature increases around DBS electrodes during normal operation (joule heating and increased metabolic activity) or coupling with an external source (e.g. magnetic resonance imaging) remains poorly understood and methods to mitigate temperature increases are being actively investigated. We developed a heat transfer finite element method (FEM) simulation of DBS incorporating the realistic architecture of Medtronic 3389 leads. The temperature changes were analyzed considering different electrode configurations, stimulation protocols and tissue properties. The heat-transfer model results were then validated using micro-thermocouple measurements during DBS lead stimulation in a saline bath. FEM results indicate that lead design (materials and geometry) may have a central role in controlling temperature rise by conducting heat. We show how modifying lead design can effectively control temperature increases. The robustness of this heat-sink approach over complimentary heat-mitigation technologies follows from several features: (1) it is insensitive to the mechanisms of heating (e.g. nature of magnetic coupling); (2) it does not interfere with device efficacy; and (3) can be practically implemented in a broad range of implanted devices without modifying the normal device operations or the implant procedure.

Robotic autopositioning of the operating microscope.

PubMed

Oppenlander, Mark E; Chowdhry, Shakeel A; Merkl, Brandon; Hattendorf, Guido M; Nakaji, Peter; Spetzler, Robert F

2014-06-01

Use of the operating microscope has become pervasive since its introduction to the neurosurgical world. Neuronavigation fused with the operating microscope has allowed accurate correlation of the focal point of the microscope and its location on the downloaded imaging study. However, the robotic ability of the Pentero microscope has not been utilized to orient the angle of the microscope or to change its focal length to hone in on a predefined target. To report a novel technology that allows automatic positioning of the operating microscope onto a set target and utilization of a planned trajectory, either determined with the StealthStation S7 by using preoperative imaging or intraoperatively with the microscope. By utilizing the current motorized capabilities of the Zeiss OPMI Pentero microscope, a robotic autopositioning feature was developed in collaboration with Surgical Technologies, Medtronic, Inc. (StealthStation S7). The system is currently being tested at the Barrow Neurological Institute. Three options were developed for automatically positioning the microscope: AutoLock Current Point, Align Parallel to Plan, and Point to Plan Target. These options allow the microscope to pivot around the lesion, hover in a set plane parallel to the determined trajectory, or rotate and point to a set target point, respectively. Integration of automatic microscope positioning into the operative workflow has potential to increase operative efficacy and safety. This technology is best suited for precise trajectories and entry points into deep-seated lesions.

Influence of cardiopulmonary bypass on platelet and neutrophil accumulations in internal organs.

PubMed

Bhujle, R; Li, J; Shastri, P; Gaffke, J N; Clift, J E; Ye, Y W; Dollar, M L; Ching, P; Chao, R; Constantinescu, A; Kulkarni, P V; Cheng, Q C; Wians, F; Jessen, M E; Eberhart, R C

1997-01-01

The authors employed gamma scintigraphy to quantify the post bypass accumulations of platelets and neutrophils in the lung, liver, and heart of adult pigs subjected to a standard 90 min regimen of normothermic cardiopulmonary bypass (CPB). Coated and uncoated microporous polypropylene oxygenator circuits were studied for Cobe Duo (Arvada, CO) oxygenators (amphophilic silicone-caprolactone oligomer [SMA] coating, n = 8 each) and Medtronic Maxima (Irvine, CA) oxygenators (Carmeda heparin coating, n = 5 each). Images of cells in the organs (deposited + blood pool) were corrected for tissue absorption and other factors and compared for a 2 hr period post CPB, using repeat measures ANOVA and rank tests. Platelet accumulations in internal organs correlated positively with whole blood platelet counts and negatively with platelet deposits in oxygenators during CPB. In general, uncoated CPB circuits significantly reduced platelet and neutrophil accumulations in lung, liver, and heart versus preCPB controls for the post CPB interval, for both systems. The SMA treatment significantly increased platelet accumulations versus uncoated controls in lung, liver, and heart for the 2 hr period, including the majority of the post CPB sampling intervals; platelet densities did not reach preCPB levels. Neutrophil accumulations were unaffected by the SMA coating. Carmeda heparin treatment significantly increased platelet accumulations in the liver, but not lung or heart. Despite preservation of circulating neutrophils observed with the Carmeda heparin treatment, neutrophil accumulations in internal organs were not elevated post CPB.

Impact of Magnetic Field on Pressures of Programmable Cerebrospinal Fluid Shunts: An Experimental Study.

PubMed

Altun, Idiris; Yuksel, Kasim Zafer; Mert, Tufan

2017-01-01

To investigate whether programmable cerebrospinal fluid (CSF) shunts are influenced by exposure to the magnetic field and to compare the effects of magnetic field in 4 different brands of programmable CSF shunts. This experimental study was performed in the laboratory using a novel design of magnetic field. Four types of programmable CSF shunts (Miethke®, Medtronic®, Sophysa® and Codman®Hakim®) were exposed to the magnetic field generated by an apparatus consisting of Helmholtz coil for 5 minutes. In every CSF shunt, initial pressures were adjusted to 110 mm H2O and pressures after exposure to magnetic field were noted. These measurements were implemented at frequencies of 5 Hz, 20 Hz, 30 Hz, 40 Hz, 60 Hz and 80 Hz. In each type, three shunts were utilized and evaluations were made twice for every shunt. At 5, 30, 40 and 60 Hz, Groups 1, 2 and 3 had significantly higher average pressures than Group 4. At 20 and 80 Hz, Groups 1 and 2 had notably different pressure values than Groups 3 and 4. Group 3 displayed the highest pressure, while Group 4 demonstrated the lowest pressure. Exposure to magnetic fields may affect the pressures of programmable CSF shunts. However, further controlled, clinical trials are warranted to elucidate the in-vivo effects of magnetic field exposure.

[Safety and short-term efficacy of renal sympathetic denervation in the treatment of resistant hypertension].

PubMed

Jiang, Xiong-jing; Liang, Tuo; Dong, Hui; Peng, Meng; Ma, Wen-jun; Guan, Ting; Zhang, Hui-min; Bian, Jin; Xu, Bo; Gao, Run-lin

2012-12-11

Transcatheter renal sympathetic denervation (RDN) is a novel technology/therapy in treating resistant hypertension. The present study aims to evaluate the safety and short-term efficacy of RDN for the treatment of resistant hypertension in a Chinese population. This prospective single-center pilot study was the first one conducted in China with Medtronic Ardian Symplicity Catheter System. Eight patients (6 males and 2 females) with resistant hypertension underwent RDN at our hospital from February to April 2012. All patients were followed up at one month and three months post-RDN. Blood pressure, use of antihypertensive medications, renal function and complications were recorded and analyzed. At one month and three months post-RDN, 24-hour ambulatory blood pressure monitoring showed mean systolic blood pressure and diastolic blood pressure decreased 10 (0 - 18) 13 (3 - 19) and 8 (-2 - 15), 9 (2 - 16) mm Hg throughout 24 hours respectively (P < 0.05, vs baseline). The number of drugs decreased from 4.3 ± 0.5 to 2.8 ± 0.9 and 2.5 ± 0.7 post-RSD respectively (P < 0.01). There was no significant change of renal function (P > 0.05). No complications were observed. The preliminary results revealed that RDN was safe and effective for the treatment of resistant hypertension in the Chinese population during a 3-month follow-up. Further large and long-term studies are warranted.

Single-side renal sympathetic denervation to treat malignant refractory hypertension in a solitary kidney patient.

PubMed

Ribichini, Flavio; Ferrara, Angela; Pighi, Michele; Pesarini, Gabriele; Gambaro, Alessia; Valvo, Enrico; Lupo, Antonio; Vassanelli, Corrado

2014-12-01

Renal sympathetic denervation (RSD) is emerging as a new therapeutic option for patients with severe hypertension refractory to medical therapy. Patients affected by renovascular or anatomical abnormalities have hitherto been systematically excluded from clinical trials with RSD because of concern about safety and the unknown efficacy of the procedure in this subgroup of patients. We describe the management of a case of RSD in a single-kidney patient with refractory hypertension; the patient had had a previous surgical right nephrectomy for renal cell carcinoma that subsequently required no other oncologic treatment. After multidisciplinary assessment, the patient underwent RSD. The procedure was performed through a 6F femoral access using the Symplicity™ RSD system (Medtronic, Mountain View, CA, USA). Radiofrequency was applied to the renal artery wall in 6 different points under general sedation with midazolam to control back pain caused by the procedure, that was performed without periprocedural complications. The patient was discharged 2 days later after a control of the vascular access site and routine biochemical examinations. The following 9-month follow up showed a significant reduction in blood pressure and stable renal function, without signs of renal damage. Our report confirms the feasibility of RSD in this delicate context, without evident negative effects on kidney function and with a significant reduction in blood pressure. Future studies are needed to fully clarify the value of RSD in single-kidney patients.

New Protocol for Skin Landmark Registration in Image-Guided Neurosurgery: Technical Note.

PubMed

Gerard, Ian J; Hall, Jeffery A; Mok, Kelvin; Collins, D Louis

2015-09-01

Newer versions of the commercial Medtronic StealthStation allow the use of only 8 landmark pairs for patient-to-image registration as opposed to 9 landmarks in older systems. The choice of which landmark pair to drop in these newer systems can have an effect on the quality of the patient-to-image registration. To investigate 4 landmark registration protocols based on 8 landmark pairs and compare the resulting registration accuracy with a 9-landmark protocol. Four different protocols were tested on both phantoms and patients. Two of the protocols involved using 4 ear landmarks and 4 facial landmarks and the other 2 involved using 3 ear landmarks and 5 facial landmarks. Both the fiducial registration error and target registration error were evaluated for each of the different protocols to determine any difference between them and the 9-landmark protocol. No difference in fiducial registration error was found between any of the 8-landmark protocols and the 9-landmark protocol. A significant decrease (P < .05) in target registration error was found when using a protocol based on 4 ear landmarks and 4 facial landmarks compared with the other protocols based on 3 ear landmarks. When using 8 landmarks to perform the patient-to-image registration, the protocol using 4 ear landmarks and 4 facial landmarks greatly outperformed the other 8-landmark protocols and 9-landmark protocol, resulting in the lowest target registration error.

An Adaptive Nonlinear Basal-Bolus Calculator for Patients With Type 1 Diabetes

PubMed Central

Boiroux, Dimitri; Aradóttir, Tinna Björk; Nørgaard, Kirsten; Poulsen, Niels Kjølstad; Madsen, Henrik; Jørgensen, John Bagterp

2016-01-01

Background: Bolus calculators help patients with type 1 diabetes to mitigate the effect of meals on their blood glucose by administering a large amount of insulin at mealtime. Intraindividual changes in patients physiology and nonlinearity in insulin-glucose dynamics pose a challenge to the accuracy of such calculators. Method: We propose a method based on a continuous-discrete unscented Kalman filter to continuously track the postprandial glucose dynamics and the insulin sensitivity. We augment the Medtronic Virtual Patient (MVP) model to simulate noise-corrupted data from a continuous glucose monitor (CGM). The basal rate is determined by calculating the steady state of the model and is adjusted once a day before breakfast. The bolus size is determined by optimizing the postprandial glucose values based on an estimate of the insulin sensitivity and states, as well as the announced meal size. Following meal announcements, the meal compartment and the meal time constant are estimated, otherwise insulin sensitivity is estimated. Results: We compare the performance of a conventional linear bolus calculator with the proposed bolus calculator. The proposed basal-bolus calculator significantly improves the time spent in glucose target (P < .01) compared to the conventional bolus calculator. Conclusion: An adaptive nonlinear basal-bolus calculator can efficiently compensate for physiological changes. Further clinical studies will be needed to validate the results. PMID:27613658

The utility of trans-catheter aortic valve replacement after commercialization: does the European experience provide a glimpse into the future use of this technology in the United States?

PubMed

Linke, Axel; Walther, Thomas; Schuler, Gerhard

2010-03-01

Treatment of aortic stenosis remains challenging in older individuals, as their perioperative mortality for open heart surgery is increased due to comorbidities. Transcatheter aortic valve implantation using the CoreValve ReValving System (Medtronic, Minneapolis, USA) and the Edwards SAPIEN transcatheter heart valve (THV; Edwards Lifescience, Irvine, California, USA) represents an alternative to conventional valve replacement in elderly patients that have a high risk for conventional surgery. This article summarizes the evidence-base from recent clinical trials. The early results of these landmark studies suggest that transcatheter aortic valve implantation with either one of the prosthesis is feasible, safe, improves hemodynamics and, therefore, might be an alternative to conventional aortic valve replacement in very high-risk patients. However, all of the available transcatheter heart valves have certain disadvantages, limiting their use in daily clinical practice. The process of decision making, which valve to use and which access route to choose is illustrated in this article through clinical case scenarios. Additionally, the lessons learned thus far from the European perspective and the potential impact on the future use in the US are discussed. Despite of the progress in this field, we are still lacking an optimal transcatheter heart valve. Once it is available, we can take the plunge to compare transcatheter valve implantation with convention surgery in severe aortic stenosis!

Accuracy of Continuous Glucose Monitoring before, during, and after Aerobic and Anaerobic Exercise in Patients with Type 1 Diabetes Mellitus.

PubMed

Biagi, Lyvia; Bertachi, Arthur; Quirós, Carmen; Giménez, Marga; Conget, Ignacio; Bondia, Jorge; Vehí, Josep

2018-03-09

Continuous glucose monitoring (CGM) plays an important role in treatment decisions for patients with type 1 diabetes under conventional or closed-loop therapy. Physical activity represents a great challenge for diabetes management as well as for CGM systems. In this work, the accuracy of CGM in the context of exercise is addressed. Six adults performed aerobic and anaerobic exercise sessions and used two Medtronic Paradigm Enlite-2 sensors under closed-loop therapy. CGM readings were compared with plasma glucose during different periods: one hour before exercise, during exercise, and four hours after the end of exercise. In aerobic sessions, the median absolute relative difference (MARD) increased from 9.5% before the beginning of exercise to 16.5% during exercise ( p < 0.001), and then decreased to 9.3% in the first hour after the end of exercise ( p < 0.001). For the anaerobic sessions, the MARD before exercise was 15.5% and increased without statistical significance to 16.8% during exercise realisation ( p = 0.993), and then decreased to 12.7% in the first hour after the cessation of anaerobic activities ( p = 0.095). Results indicate that CGM might present lower accuracy during aerobic exercise, but return to regular operation a few hours after exercise cessation. No significant impact for anaerobic exercise was found.

Surfactants in the management of rhinopathologies

PubMed Central

Rosen, Philip L.; Palmer, James N.; O'Malley, Bert W.

2013-01-01

Background: Surfactants are a class of amphiphilic surface active compounds that show several unique physical properties at liquid–liquid or liquid–solid surface interfaces including the ability to increase the solubility of substances, lower the surface tension of a liquid, and decrease friction between two mediums. Because of these unique physical properties several in vitro, ex vivo, and human trials have examined the role of surfactants as stand-alone or adjunct therapy in recalcitrant chronic rhinosinusitis (CRS). Methods: A review of the literature was performed. Results: The data from three different surfactants have been examined in this review: citric acid zwitterionic surfactant (CAZS; Medtronic ENT, Jacksonville FL), Johnson's Baby Shampoo (Johnson & Johnson, New Brunswick NJ), and SinuSurf (NeilMed Pharmaceuticals, Santa Rosa, CA). Dilute surfactant therapy shows in vitro antimicrobial effects with modest inhibition of bacterial biofilm formation. In patients with CRS, surfactants may improve symptoms, most likely through its mucolytic effects. In addition, surfactants have several distinct potential benefits including their ability to improve an irrigant's penetration of the nonoperated sinus and their synergistic effects with antibiotics. However, surfactants potential for nasal irritation and possible transient ciliotoxicity may limit their use. Conclusion: Recent data suggest a possible therapeutic role of surfactants in treating rhinopathologies associated with mucostasis. Further investigation, including a standardization of surfactant formulations, is warranted to further elucidate the potential benefits and drawbacks of this therapy. PMID:23710951

Manual Intracardiac Electrogram Method Is Accurate Alternative to Echocardiography for Atrioventricular and Interventricular Optimization in Cardiac Resynchronization Therapy.

PubMed

Pezo Nikolić, Borka; Lovrić, Daniel; Ljubas Maček, Jana; Rešković Lukšić, Vlatka; Matasić, Richard; Šeparović Hanževački, Jadranka

2017-12-01

Some manufacturers do not provide automated intracardiac electrogram method (IEGM) systems for atrioventricular (AV) and interventricular (VV) delay optimization in cardiac resynchronization therapy (CRT). We aimed to evaluate the accuracy of manual IEGM method in 48 patients previously implanted with Medtronic Syncra CRT. All patients underwent standard device interrogation followed by CRT optimization by IEGM method and by echocardiography one month after implantation. The patient mean age was 60.7±11.8 years and there were 33 (68.8%) males. After CRT implantation, the left ventricular ejection fraction increased from 28.0±7.9% to 39.1±11.0% (p<0.001). Optimal aortic flow Velocity Time Integral (aVTI) was obtained when VV was set to 20-50 ms left ventricular pre-activation. There was a strong correlation between VV values determined by echocardiography and IEGM (R=0.823, p<0.001). We found no significant difference in AV, VV and aVTI values between echocardiography and IEGM method. However, IEGM was significantly less time-consuming than echocardiography [20 (10-28) vs. 40 (35-60) minutes, p<0.001]. Manual IEGM method may be good alternative to echocardiography and automated IEGM method. It also emphasizes the need for implementation of automated IEGM systems in as many CRT devices as possible.

Temperature control at DBS electrodes using a heat sink: experimentally validated FEM model of DBS lead architecture

NASA Astrophysics Data System (ADS)

Elwassif, Maged M.; Datta, Abhishek; Rahman, Asif; Bikson, Marom

2012-08-01

There is a growing interest in the use of deep brain stimulation (DBS) for the treatment of medically refractory movement disorders and other neurological and psychiatric conditions. The extent of temperature increases around DBS electrodes during normal operation (joule heating and increased metabolic activity) or coupling with an external source (e.g. magnetic resonance imaging) remains poorly understood and methods to mitigate temperature increases are being actively investigated. We developed a heat transfer finite element method (FEM) simulation of DBS incorporating the realistic architecture of Medtronic 3389 leads. The temperature changes were analyzed considering different electrode configurations, stimulation protocols and tissue properties. The heat-transfer model results were then validated using micro-thermocouple measurements during DBS lead stimulation in a saline bath. FEM results indicate that lead design (materials and geometry) may have a central role in controlling temperature rise by conducting heat. We show how modifying lead design can effectively control temperature increases. The robustness of this heat-sink approach over complimentary heat-mitigation technologies follows from several features: (1) it is insensitive to the mechanisms of heating (e.g. nature of magnetic coupling); (2) it does not interfere with device efficacy; and (3) can be practically implemented in a broad range of implanted devices without modifying the normal device operations or the implant procedure.

Effectiveness of continuous glucose monitoring in children, adolescents, and young adults with poorly controlled type 1 diabetes.

PubMed

Lewis, Kevin R; McCrone, Susan; Deiriggi, Pamela; Bendre, Sachin

2017-01-01

The purpose of this study was to determine the effect of continuous glucose monitoring (CGM) on glycemic control in children, adolescents, and young adults ages 7-21 years with poorly controlled diabetes HbA1c 9.0% or more (74 mmol/mol IFCC). The primary outcome was improvement in HbA1c. The secondary outcome included self-reported hypoglycemia. This 12-week study used a prospective, one-group, pre- and posttest pre-experimental design with a convenience sample. The study used the Medtronic Guardian CGM with Enlite Sensor. Thirty-three subjects enrolled in the study. The mean age of the participants was 15.57 years, range was 11-20 years, 47.6% were male, and 52.4% were female. Twenty-one (63.6%) completed the final study visit. There was a clinically and statistically significant reduction of 1.46 (SD = 1.6711) (p = .001) in HbA1c at 12 weeks. Fifteen of the 21 participants (71.4%) had an HbA1c reduction of greater than 0.5%. The CGM monitor was worn a mean of 4.262 days a week. None of the subjects reported significant hypoglycemia while wearing the monitor. CGM was effective in improving glycemic control in this population with poorly controlled diabetes. © 2016, Wiley Periodicals, Inc.

A Case of a Cardiac Resynchronization Therapy-Defibrillator Exhibiting a Lower and Alternately Variable Basic Rate.

PubMed

Iwazaki, Keigo; Kojima, Toshiya; Murasawa, Takahide; Yokota, Jun; Tanimoto, Hikaru; Matsuda, Jun; Fukuma, Nobuaki; Matsubara, Takumi; Shimizu, Yu; Oguri, Gaku; Hasumi, Eriko; Kubo, Hitoshi; Chang, Kyungho; Fujiu, Katsuhito; Komuro, Issei

2018-05-30

A cardiac resynchronization therapy defibrillator (CRT-D) (Medtronic Inc. Protecta XT) was implanted in a 67-year-old man who had cardiac sarcoidosis with extremely low cardiac function. He had ventricular tachycardia which was controlled by catheter ablation, medication and pacing. The programmed mode was DDI, lower rate was 90 beats/minute, paced AV delay was 150 ms, and the noncompetitive atrial pacing (NCAP) function was programmed as 300 ms.After his admission for pneumonia and heart failure, we changed his DDI mode to a DDD mode because he had atrial tachycardia, which led to inadequate bi-ventricular pacing. After a while, there were cycle lengths which were longer than his device setting and alternately varied. We were able to avoid this phenomenon with AV delay of 120 ms and NCAP of 200 ms.NCAP is an algorithm which creates a gap above a certain period after the detection of an atrial signal during the postventricular atrial refractory period of the pacemaker. This is to prevent atrial tachycardia and repetitive non-reentrant ventriculoatrial (VA) synchrony in the presence of retrograde VA conduction. But in this case, NCAP algorithm induced much lower rate than the programmed basic lower rate. This situation produced some arrhythmias and exacerbated symptoms of heart failure. This had to be paid attention to, especially when the device was programmed at high basic heart rate.

[Our experience about the use of resorbable plates in the treatment of craniostenosis].

PubMed

Grassiot, B; Delabar, V; Szathmari, A; Beuriat, P A; Paulus, C; Mottolese, C

2015-09-01

The use of resorbable plates increases for craniosynostosis surgery. This material, based on polymere (PLA, PGA) can replace steel wire and non resorbable plates. A few studies present surgical results about the use of this material with a long follow-up. We present our ten years experience of using resorbable material for craniosynostosis treatment in children. Between 2002 and 2012, we operated 283 craniosynostosis (98 scaphocephalies, 55 trigonocephalies, 79 plagiocephalies et 51 craniofaciostenoses). Among these surgeries, 211 were realized with resorbable material (plates and screws). Different criteria were observed: the esthetic result, the infection rate, the re-intervention, the bone defects and the inflammatory granuloma. Among the 211 craniosynostosis, we found 62 plagiocephalies, 66 scaphocephalies, 50 trigonocephalies, 33 craniofaciostenoses. All the reconstructions were realized with the same resorbable material (Macropore by Medtronic). The rate of complications was low: one scar infection without participation of material for two patients (0.9%), a pseudo-meningocele for two patients (0.9%), epilepsy for four children (1.8%) and bone defect for 15 (7%). We observed no granuloma for these patients. Our experience of ten years using resorbable material is very satisfactory. This material permits to realize solid and esthetic reconstructions with a low rate of infection without dangerous reaction for children in young age. Copyright © 2015 Elsevier Masson SAS. All rights reserved.

Visually Evoked Potentials after Panretinal Photocoagulation in Omani Patients with Uncontrolled Diabetes Mellitus

PubMed Central

Shenoy, Radha; Al-Belushi, Habiba; Al-Ajmi, Sadiqa; Al-Nabhani, Susan Margaret; Ganguly, Shyam Sunder; Bialasiewicz, Alexander A.

2008-01-01

Aim: To report on the changes of latency and amplitudes of the pattern VEP in patients with uncontrolled diabetes mellitus II and I before and after panretinal laser treatment. Design: Single center hospital based comparative study. Methods: One hundred eyes of patients with proliferative diabetic vitreoretinopathy, and HbA1C ≥ 10 percent were subjected to Pattern Visually Evoked Potentials (Medtronic keyopint system, Nicolet) prior to and 4 weeks after PRP. Results were compared to age-matched non-diabetic controls. Chi-Square test, and paired ‘t’ test were used for statistical analysis. Results: Preoperative mean VEP amplitude was 8.35mV±3.71, and not significantly different to the control group (mean 10.51mV±3.34) (chi square test p=1). Mean preoperative P100 latency was 106.93±7.90ms and significantly different to the control group (103.21±7.65ms) (paired t-test p=0.001). After laser treatment, VEP amplitudes decreased in 48/100 eyes (mean total 5.11mV±2.4), and P100 latency increased in 75/100 eyes (mean total 110.47±7.35ms). Conclusion: In this study, PRP was followed by a significant decrease in VEP amplitudes in 48 percent and increase in latency in 75 percent of eyes. PMID:21346837

Health Resource Utilization and Cost for Patients with Incontinent Overactive Bladder Treated with Anticholinergics.

PubMed

Yehoshua, Alon; Chancellor, Michael; Vasavada, Sandip; Malone, Daniel C; Armstrong, Edward P; Joshi, Manher; Campbell, Karen; Pulicharam, Riya

2016-04-01

Overactive bladder (OAB) is a common medical condition with significant economic and humanistic burden. Inadequately managed OAB may exacerbate or result in comorbidities such as depression, falls, and urinary tract infections, which can further increase the burden to the health care system. Anticholinergics are often prescribed for management of OAB with urinary incontinence ("wet" OAB). However, research has shown that patient adherence and persistence to anticholinergic therapy is poor, with approximately 80% of patients ultimately failing their first prescribed anticholinergic medication within the first year. While there has been a fair amount of research on the economic burden of OAB, the real-world impact of initiating anticholinergic therapy in patients with wet OAB has not been well studied. To compare falls/fractures, anxiety/depression, health care resource utilization, and health care costs between a cohort of patients with wet OAB who initiated anticholinergic therapy and a matched cohort of patients without OAB. This study was a retrospective medical and pharmacy claims analysis. Cases were members of a primary care-based, multispecialty physician medical group located in California. Cases were eligible for inclusion if they were prescribed anticholinergic therapy between January 2008 and May 2012 based on pharmacy claims, had a diagnosis of OAB, and reported having ≥ 1 urinary incontinence episode per day. Wet OAB cases were matched to non-OAB controls in a 1:3 ratio based on sex, age, and observation time. Medical and pharmacy claims data were used to analyze patient comorbidities, as well as track health care resource utilization (HRU) and direct payer costs. After initiating anticholinergic therapy, wet OAB patients had a 46% higher adjusted risk of experiencing falls/fractures (P < 0.001) and a 33% higher adjusted risk of experiencing depression/anxiety (P = 0.022) than non-OAB patients. Wet OAB was significantly associated with increased HRU rates of hospital admissions, outpatient visits, prescriptions filled, and diagnostic tests performed. After adjustment for covariates, total health care cost was 33% higher for wet OAB patients than non-OAB patients, resulting in an increased cost of $1,746 per member per year. The findings of this research suggest OAB patients who initiate anticholinergic therapy and still experience incontinence are at a greater risk for comorbidities such as falls/fractures and depression/anxiety, and use significantly more health care resources, than patients without OAB. Programs to improve patient monitoring and referrals, the appropriate use of alternative treatments within guidelines, and adherence to evidence-based practice parameters may improve clinical outcomes and decrease HRU for these patients. This study was sponsored by Allergan, Irvine, California, which reviewed and approved the final manuscript. At the time of the study, Yehoshua had received a fellowship at the University of Arizona, which was funded by Allergan. Yehoshua, Joshi, and Campbell are employees of Allergan. Vasaveda has received consulting fees from Allergan, Medtronic, and Boston Scientific. Chancelor has received consulting fees from Allergan and Medtronic. All authors met the ICMJE authorship criteria. Neither honoraria nor payments were made for authorship. Study design was created by Yehoshua, Pulicharam, Malone, and Armstrong. Pulicharam took the lead in data collection, along with Chancellor and Campbell, and data interpretation was performed by Chancellor, Vasavada, Malone, and Armstrong. The manuscript was written by Yehoshua and revised by Joshi and Yehoshua, with assistance from the other authors.

Evaluation of different diameter arterial tubing and arterial cannulae in simulated neonatal/pediatric cardiopulmonary bypass circuits.

PubMed

Wang, Shigang; Rosenthal, Tami; Kunselman, Allen R; Ündar, Akif

2015-01-01

The objective of this study is to evaluate three different diameters of arterial tubing and three diameters of arterial cannulae in terms of pressure drop, and hemodynamic energy delivery in simulated neonatal/pediatric cardiopulmonary bypass (CPB) circuits. The CPB circuit consisted of a Terumo Capiox Baby FX05 oxygenator (Terumo Corporation, Tokyo, Japan), arterial tubing (1/4 in, 3/16 in, or 1/8 in × 150 cm), and a Medtronic Bio-Medicus arterial cannula (8, 10, or 12 Fr; Medtronic, Inc., Minneapolis, MN, USA). The pseudo patient's pressure was maintained at 50 mm Hg. The circuit was primed using lactated Ringer's solution and heparinized packed human red blood cells (hematocrit 30%). Trials were conducted at different flow rates and temperatures (35 and 28°C). Flow and pressure data were collected using a custom-based data acquisition system. Using 8 Fr arterial cannula at 500 mL/min, small diameter arterial tubing generated higher circuit pressure (294.6 ± 0.1 mm Hg [1/8 in], 213.5 ± 0.5 mm Hg [3/16 in], 208.4 ± 0.4 mm Hg [1/4 in] at 35°C) and arterial line pressure drop (158.3 ± 0.1 mm Hg [1/8 in], 79.6 ± 0.1 mm Hg [3/16 in], 62.1 ± 0.1 mm Hg [1/4 in] at 35°C). Using 10 Fr arterial cannula at 1000 mL/min, pre-oxygenator pressures were 266.8 ± 0.2 mm Hg (3/16 in) and 248.0 ± 0.3 mm Hg (1/4 in); arterial line pressure drops were 111.6 ± 0.0 mm Hg (3/16 in) and 74.0 ± 0.1 mm Hg (1/4 in) at 35°C. When using 12 Fr arterial cannula at 1500 mL/min, preoxygenator pressures reached 324.4 ± 0.3 mm Hg (3/16 in) and 302.5 ± 0.4 mm Hg (1/4 in); arterial line pressure drops were 154.0 ± 0.1 mm Hg (3/16 in) and 92.0 ± 0.2 mm Hg (1/4 in) at 35°C. Pressure drops across arterial line tubing were main CPB circuit pressure drops. High flow rate, hypothermia, small diameter arterial tubing. and arterial cannula created more hemodynamic energy at the preoxygenator site, but energy loss across CPB circuit also increased. Although small diameter (<1/4 in ID) arterial tubing may decrease total CPB priming volume, it also led to significantly higher circuit pressure, higher pressure drop, and more hemodynamic energy loss across CPB circuit. Larger diameter arterial cannula had less pressure drop and allowed more hemodynamic energy delivery to the patient. Copyright © 2015 International Center for Artificial Organs and Transplantation and Wiley Periodicals, Inc.

A pilot study of implantable cardiac device interrogation by emergency department personnel.

PubMed

Neuenschwander, James F; Hiestand, Brian C; Peacock, W Frank; Billings, John M; Sondrup, Cole; Hummel, John D; Abraham, William T

2014-03-01

Implanted devices (eg, pacemakers and defibrillators) provide valuable information and may be interrogated to obtain diagnostic information and to direct management. During admission to an emergency department (ED), significant time and cost are spent waiting for device manufacturer representatives or cardiologists to access the data. If ED personnel could safely interrogate implanted devices, more rapid disposition could occur, thus leading to potentially better outcomes at a reduced cost. This was a pilot study examining the feasibility of ED device interrogation. This was a prospective convenience sample study of patients presenting to the ED with any chief complaint and who had an implantable device capable of being interrogated by a Medtronic reader. After obtaining informed consent, study patients underwent device interrogation by ED research personnel. After reviewing the device data, the physician documented their opinions of the value of data in aiding care. Patients were followed up at intervals ranging from 30 days out to 1 year to determine adverse events relating to interrogation. Forty-four patients underwent device interrogation. Their mean age was 56 ± 14.7 years (range, 28-83), 75% (33/44) were male and 75% (33/44) were hospitalized from the ED. The interrogations took less than 10 minutes 89% of the time. In 60% of the cases, ED physicians reported the data-assisted patient care. No adverse events were reported relating to the ED interrogations. In this pilot study, we found that ED personnel can safely and quickly interrogate implantable devices to obtain potentially useful clinical data.

Can Vacuum Assisted Venous Drainage be Achieved using a Roller Pump in an Emergency? A Pilot Study using Neonatal Circuitry

PubMed Central

Hill, S. L.; Holt, D. W.

2007-01-01

Abstract: There has been much advancement in perfusion technology over its 50 years of progression. One of these techniques is vacuum-assisted venous drainage (VAVD). Many perfusionists augment venous drainage using VAVD, typically from a wall vacuum source. This study explores alternates to providing VAVD if the wall vacuum fails. In two porcine laboratories, ∼36 in. of 3/16-in. tubing was connected to a sucker return port and placed into the roller head next to the arterial pump. The vacuum was monitored with a DLP pressure monitoring system (Medtronic). This system was connected to small-bore tubing and attached to a stopcock on top of the reservoir. The vacuum was regulated using another stopcock connected to a non-filtered luer lock port on top of the reservoir or by a segment of 3 × 0.25-in.-diameter tubing attached to the vent port with a c-clamp. Vacuum drainage was achieved, ranging from −18 mmHg to −71 mmHg by manipulating the stopcock or c-clamp. Changes in venous drainage were seen by volume fluctuations in the venous reservoir. The vacuum was adjusted to account for dramatic changes. Augmented venous drainage using a roller pump can be achieved successfully during cardiopulmonary bypass (CPB). This method of active drainage can be used in lieu of wall suction or during times of emergency if wall suction fails. PMID:18293812

Continuous glucose monitoring--a study of the Enlite sensor during hypo- and hyperbaric conditions.

PubMed

Adolfsson, Peter; Örnhagen, Hans; Eriksson, Bengt M; Cooper, Ken; Jendle, Johan

2012-06-01

The performance and accuracy of the Enlite(™) (Medtronic, Inc., Northridge, CA) sensor may be affected by microbubble formation at the electrode surface during hypo- and hyperbaric conditions. The effects of acute pressure changes and of prewetting of sensors were investigated. On Day 1, 24 sensors were inserted on the right side of the abdomen and back in one healthy individual; 12 were prewetted with saline solution, and 12 were inserted dry. On Day 2, this procedure was repeated on the left side. All sensors were attached to an iPro continuous glucose monitoring (CGM) recorder. Hypobaric and hyperbaric tests were conducted in a pressure chamber, with each test lasting 105 min. Plasma glucose values were obtained at 5-min intervals with a HemoCue(®) (Ängelholm, Sweden) model 201 glucose analyzer for comparison with sensor glucose values. Ninety percent of the CGM systems operated during the tests. The mean absolute relative difference was lower during hyperbaric than hypobaric conditions (6.7% vs. 14.9%, P<0.001). Sensor sensitivity was slightly decreased (P<0.05) during hypobaric but not during hyperbaric conditions. Clarke Error Grid Analysis showed that 100% of the values were found in the A+B region. No differences were found between prewetted and dry sensors. The Enlite sensor performed adequately during acute pressure changes and was more accurate during hyperbaric than hypobaric conditions. Prewetting the sensors did not improve accuracy. Further studies on type 1 diabetes subjects are needed under various pressure conditions.

Industry Payments to Obstetrician-Gynecologists: An Analysis of 2014 Open Payments Data.

PubMed

Tierney, Nicole M; Saenz, Cheryl; McHale, Michael; Ward, Kristy; Plaxe, Steven

2016-02-01

To evaluate publically available, individually identified data regarding industry payments made to obstetrician-gynecologists (ob-gyns) during 2014 posted on the Centers for Medicare & Medicaid Services' Open Payments website for the purposes of encouraging ob-gyns to partake in disclosure of their fiscal relationships to patients and to take an active role in maintaining accuracy of their payment data. In this retrospective study, we reviewed the Centers for Medicare & Medicaid Services' Open Payments website for all 2014 nonresearch payments to ob-gyns. We compared payments to ob-gyns with payments to those in other specialties as well as subspecialties within the field of obstetrics and gynecology. Univariate statistical analyses were performed. Payments to ob-gyns totaled $60,004,472 (3.3% of the total value transferred in 2014) and went to 29,783 physician recipients. Fifty percent of these payments were for royalties and licensing. Obstetrics and gynecology ranked seventh in total number of payments made to a single specialty (n=311,485), and 20th of 35 specialties for highest median payment ($140, interquartile range $50-347). Medtronic USA, Inc. was the leading payer to ob-gyns. Ob-gyns are listed as having received substantial payments from industry in 2014. Because this information is publically available, we suggest physicians become familiar with payment data and the correction process, keep independent records, and register for updates to most effectively manage perceived, or real, conflicts of interest.

Application of drag-reducing polymer solutions as test fluids for in vitro evaluation of potential blood damage in blood pumps.

PubMed

Daly, Amanda R; Sobajima, Hideo; Olia, Salim E; Takatani, Setsuo; Kameneva, Marina V

2010-01-01

In vitro evaluation of the potential of a circulatory-assist device to damage blood cells has generally been performed using blood from various species. Problems with this approach include the variability of blood sensitivity to mechanical stress in different species, preparation of blood including the adjustment of hematocrit to a standard value, changes in the mechanical properties of blood that occur during storage, and necessity to pool blood samples to obtain an adequate amount of blood for in vitro circulating systems. We investigated whether the mechanical degradation of a drag-reducing polymer (DRP) solution resulting in the loss of drag-reducing ability can indicate the degree of shear-induced blood damage within blood pumps. DRP solution (polyethylene oxide, 4,500 kDa, 1,000 ppm) or porcine blood were driven through a turbulent flow system by a centrifugal pump, either the Bio-Pump BPX-80 (Medtronic, Inc.) or CentriMag (Levitronix LLC) at a constant pressure gradient of 300 mm Hg for 120 minutes. DRP mechanical degradation was evaluated by reduction of flow rate and solution viscosity. A proposed index of DRP mechanical degradation (PDI) is similar to the normalized index of hemolysis (NIH) typically used to quantify the results of in vitro testing of blood pumps. Results indicate that the mechanical degradation of DRP solutions may provide a sensitive standard method for the evaluation of potential blood trauma produced by blood pumps without the use of blood.

Application of Drag-Reducing Polymer Solutions as Test Fluids for In Vitro Evaluation of Potential Blood Damage in Blood Pumps

PubMed Central

Daly, Amanda R.; Sobajima, Hideo; Olia, Salim E.; Takatani, Setsuo; Kameneva, Marina V.

2011-01-01

In vitro evaluation of the potential of a circulatory-assist device to damage blood cells has generally been performed using blood from various species. Problems with this approach include the variability of blood sensitivity to mechanical stress in different species, preparation of blood including the adjustment of hematocrit to a standard value, changes in the mechanical properties of blood that occur during storage, and necessity to pool blood samples to obtain an adequate amount of blood for in vitro circulating systems. We investigated whether the mechanical degradation of a drag-reducing polymer (DRP) solution resulting in the loss of drag-reducing ability can indicate the degree of shear-induced blood damage within blood pumps. DRP solution (polyethylene oxide, 4,500 kDa, 1,000 ppm) or porcine blood were driven through a turbulent flow system by a centrifugal pump, either the Bio-Pump BPX-80 (Medtronic, Inc.) or CentriMag (Levitronix LLC) at a constant pressure gradient of 300 mm Hg for 120 minutes. DRP mechanical degradation was evaluated by reduction of flow rate and solution viscosity. A proposed index of DRP mechanical degradation (PDI) is similar to the normalized index of hemolysis (NIH) typically used to quantify the results of in vitro testing of blood pumps. Results indicate that the mechanical degradation of DRP solutions may provide a sensitive standard method for the evaluation of potential blood trauma produced by blood pumps without the use of blood. PMID:20019596

Continuous glucose monitoring: 40 years, what we've learned and what's next.

PubMed

Gifford, Raeann

2013-07-22

After 40 years of research and development, today continuous glucose monitoring (CGM) is demonstrating the benefit it provides for millions with diabetes. To provide in vivo accuracy, new permselective membranes and mediated systems have been developed to prevent enzyme saturation and to minimize interference signals. Early in vivo implanted sensor research clearly showed that the foreign body response was a more difficult issue to overcome. Understanding the biological interface and circumventing the inflammatory response continue to drive development of a CGM sensor with accuracy and reliability performance suitable in a closed-loop artificial pancreas. Along with biocompatible polymer development, other complimentary algorithm and data analysis techniques have improved the performance of commercial systems significantly. For example, the mean average relative difference of Dexcom's CGM system improved from 26 to 14% and its use-life was extended from 3 to 7 d. Significant gains in usability, including size, flexibility, insertion, calibration, and data interface, have been incorporated into new generations of commercial CGM systems. Besides Medtronic, Dexcom, and Abbott, other major players are also investing in CGM. Becton Dickinson is conducting clinical trials with an optical galactose glucose binding system. Development of fully implanted sensor systems fulfills the desire for a discreet, reliable CGM system. Research continues to find innovative ways to help make living with diabetes easier and more normal, and new segments are being pursued (intensive care unit, surgery, behavior modification) in which CGM is being utilized. Copyright © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Exponential increase in postprandial blood-glucose exposure with increasing carbohydrate loads using a linear carbohydrate-to-insulin ratio.

PubMed

Marran, K J; Davey, B; Lang, A; Segal, D G

2013-04-10

Postprandial glucose excursions contribute significantly to average blood glucose, glycaemic variability and cardiovascular risk. Carbohydrate counting is a method of insulin dosing that balances carbohydrate load to insulin dose using a fixed ratio. Many patients and current insulin pumps calculate insulin delivery for meals based on a linear carbohydrate-to-insulin relationship. It is our hypothesis that a non-linear relationship exists between the amounts of carbohydrate consumed and the insulin required to cover it. To document blood glucose exposure in response to increasing carbohydrate loads on fixed carbohydrate-to-insulin ratios. Five type 1 diabetic subjects receiving insulin pump therapy with good control were recruited. Morning basal rates and carbohydrate- to-insulin ratios were optimised. A Medtronic glucose sensor was used for 5 days to collect data for area-under-the-curve (AUC) analysis, during which standardised meals of increasing carbohydrate loads were consumed. Increasing carbohydrate loads using a fixed carbohydrate-to-insulin ratio resulted in increasing glucose AUC. The relationship was found to be exponential rather than linear. Late postprandial hypoglycaemia followed carbohydrate loads of >60 g and this was often followed by rebound hyperglycaemia that lasted >6 hours. A non-linear relationship exists between carbohydrates consumed and the insulin required to cover them. This has implications for control of postprandial blood sugars, especially when consuming large carbohydrate loads. Further studies are required to look at the optimal ratios, duration and type of insulin boluses required to cover increasing carbohydrate loads.

[Complications of intrathecal baclofen therapy].

PubMed

Paskhin, D L; Dekopov, A V; Tomsky, A A; Isagulyan, E D; Salova, E M

To analyze complications of intrathecal baclofen therapy and identify high-risk groups. We implanted 52 pumps to spastic patients for chronic intrathecal baclofen infusion. Two groups of patients were distinguished: 23 patients with spinal spasticity (group 1) and 29 patients with cerebral spasticity (group 2). The mean patient age was 37.2±14.6 years in group 1 and 17.3±10.3 years in group 2. Surgery was performed according to a standard procedure. A Medstream (Codman) pump was implanted in 10 cases, and a Synchromed II (Medtronic) pump was implanted in the remaining 42 cases. Complications developed in 12 (23%) patients. We divided complications into 3 groups: baclofen underdose, baclofen overdose, and others. Insufficiency of intrathecal therapy was observed in 7 cases, which was caused by catheter migration (5 cases) and pump dysfunction (2 cases). In one case, baclofen overdose was observed after air travel. Other complications included 4 cases of persistent peri-implant seroma and infectious complications. Groups with a high risk of complications were identified based on an analysis of the results. Patients with severe dystonia of the trunk muscles have an increased risk of spinal catheter migration. Pronounced communicating hydrocephalus is associated with the risk of cerebrospinal fluid leak through a catheter shaft channel. Weakness of the axial musculature can lead to progression of scoliotic deformity. In some cases, chronic intrathecal baclofen therapy can be accompanied by various complications. This technique should be carefully used in patients from high-risk groups.

Design of the evolution of management strategies of heart failure patients with implantable defibrillators (EVOLVO) study to assess the ability of remote monitoring to treat and triage patients more effectively

PubMed Central

Marzegalli, Maurizio; Landolina, Maurizio; Lunati, Maurizio; Perego, Giovanni B; Pappone, Alessia; Guenzati, Giuseppe; Campana, Carlo; Frigerio, Maria; Parati, Gianfranco; Curnis, Antonio; Colangelo, Irene; Valsecchi, Sergio

2009-01-01

Background Heart failure patients with implantable defibrillators (ICD) frequently visit the clinic for routine device monitoring. Moreover, in the case of clinical events, such as ICD shocks or alert notifications for changes in cardiac status or safety issues, they often visit the emergency department or the clinic for an unscheduled visit. These planned and unplanned visits place a great burden on healthcare providers. Internet-based remote device interrogation systems, which give physicians remote access to patients' data, are being proposed in order to reduce routine and interim visits and to detect and notify alert conditions earlier. Methods The EVOLVO study is a prospective, randomized, parallel, unblinded, multicenter clinical trial designed to compare remote ICD management with the current standard of care, in order to assess its ability to treat and triage patients more effectively. Two-hundred patients implanted with wireless-transmission-enabled ICD will be enrolled and randomized to receive either the Medtronic CareLink® monitor for remote transmission or the conventional method of in-person evaluations. The purpose of this manuscript is to describe the design of the trial. The results, which are to be presented separately, will characterize healthcare utilizations as a result of ICD follow-up by means of remote monitoring instead of conventional in-person evaluations. Trial registration ClinicalTrials.gov: NCT00873899 PMID:19538734

Initial findings using the V8 hourglass-shaped valvuloplasty balloon for postdilatation in treating paravalvular leaks associated with transcatheter self-expanding aortic valve prosthesis.

PubMed

Latib, Azeem; Pedersen, Wesley; Maisano, Francesco; Lesser, John; Ruparelia, Neil; Figini, Filippo; Colombo, Antonio; Poulose, Anil; Kolbeck, James; Mooney, Michael; Schwartz, Robert; Youssef, Alicia; Ungs, David; Goldenberg, Irv; Sorajja, Paul

2016-06-01

The aim of this study was to assess the effect of a novel hourglass-shaped balloon on reduction of paravalvular leak (PVL) in patients undergoing transcatheter aortic valve replacement (TAVR) with self-expanding prostheses. An important limitation of TAVR compared with surgical aortic valve replacement remains the higher incidence of PVL. A commonly used strategy to treat PVL is balloon postdilatation (BPD); however, the optimal technique for treating PVL after TAVR is unknown. We examined consecutive patients with severe, symptomatic aortic stenosis who underwent TAVR with the Medtronic CoreValve followed by BPD with an InterValve V8 balloon for PVL grade ≥2+. Data from echocardiographic, multidetector computed tomographic, and angiographic images were reviewed. The primary endpoint was successful reduction in PVL to grade 1+ or less as assessed by intraprocedural echocardiography. Eleven patients were studied (median age, 82 years; 64% female). Ten patients (91%) demonstrated successful reduction in PVL after V8 BPD. In three patients, PVL was reduced to zero or trace. PVL remained unchanged in one patient (2+). Two patients had complete heart block associated with valve deployment and received permanent pacemakers. There were no occurrences of annular injury or major adverse clinical events. BPD with the V8 hourglass-shaped balloon was feasible in reducing PVL from self-expanding TAVR prostheses. © 2016 Wiley Periodicals, Inc. © 2016 Wiley Periodicals, Inc.

A compact highly efficient and low hemolytic centrifugal blood pump with a magnetically levitated impeller.

PubMed

Asama, Junichi; Shinshi, Tadahiko; Hoshi, Hideo; Takatani, Setsuo; Shimokohbe, Akira

2006-03-01

A magnetically levitated (maglev) centrifugal blood pump (CBP), intended for use as a ventricular assist device, needs to be highly durable and reliable for long-term use without any mechanical failure. Furthermore, maglev CBPs should be small enough to be implanted into patients of various size and weight. We have developed a compact maglev CBP employing a two-degree-of-freedom controlled magnetic bearing, with a magnetically suspended impeller directly driven by an internal brushless direct current (DC) motor. The magnetic bearing actively controls the radial motion of the impeller and passively supports axial and angular motions using a permanent magnet embedded in the impeller. The overall dimensions of the maglev CBP are 65 mm in diameter and 40 mm in height. The total power consumption and pump efficiency for pumping 6 L/min against a head pressure of 105 mm Hg were 6.5 W and 21%, respectively. To evaluate the characteristics of the maglev CBP when subjected to a disturbance, excitation of the base, simulating the movement of the patient in various directions, and the sudden interception of the outlet tube connected with the pump in a mock circulatory loop, simulating an unexpected kink and emergent clamp during a heart surgery, were tested by monitoring the five-degree-of-freedom motion of the impeller. Furthermore, the hemolytic characteristics of the maglev CBP were compared with those of the Medtronic Biomedicus BPX-80, which demonstrated the superiority of the maglev CBP.

Transcatheter aortic valve replacement: historical perspectives, current evidence, and future directions.

PubMed

Horne, Aaron; Reineck, Elizabeth A; Hasan, Rani K; Resar, Jon R; Chacko, Matthews

2014-10-01

Severe aortic stenosis (AS) results in considerable morbidity and mortality without aortic valve replacement and is expected to increase in prevalence with the aging population. Because AS primarily affects the elderly, many patients with comorbidities are poor candidates for surgical aortic valve replacement (SAVR) and may not be referred. Transcatheter aortic valve replacement (TAVR) has emerged as transformative technology for the management of AS over the past decade. Randomized trials have established the safety and efficacy of TAVR with improved mortality and quality of life compared with medical therapy in inoperable patients, while demonstrating noninferiority and even superiority to SAVR among high-risk operative candidates. However, early studies demonstrated an early penalty of stroke and vascular complications with TAVR as well as increased paravalvular leak as compared with SAVR. Two device platforms have been evaluated and approved for use in the United States: the Edwards SAPIEN and the Medtronic CoreValve. Early studies also suggest cost-effectiveness for TAVR. Ongoing studies are evaluating new iterations of the aforementioned TAVR devices, novel device designs, and applications of TAVR in expanded populations of patients including those with lower risk profiles as well as those with comorbidities that were excluded from early clinical trials. Future improvements in TAVR technology will likely reduce periprocedural and long-term complications. Further studies are needed to confirm device durability over long-term follow-up and explore the applicability of TAVR to broader AS patient populations. Copyright © 2014 Mosby, Inc. All rights reserved.

Denervation of nerve terminals in renal arteries: one-year follow-up of interventional treatment of arterial hypertension.

PubMed

Bartuś, Krzysztof; Sadowski, Jerzy; Kapelak, Bogusław; Litwinowicz, Radosław; Zajdel, Wojciech; Godlewski, Jacek; Bartuś, Magdalena; Zmudka, Krzysztof; Chrapusta, Anna; Konstanty-Kalandyk, Janusz; Węgrzyn, Piotr; Sobotka, Paul A

2014-01-01

Arterial hypertension is the most common cardiovascular system disease, affecting nearly one billion people worldwide. Despite the widespread use of antihypertensive medications, in some groups of patients an optimal blood pressure (BP) cannot be achieved. To assess BP reduction in patients with resistant hypertension after a catheter-based renal sympathetic denervation procedure and to report vascular and kidney safety in one-year follow-up. Twenty eight patients with diagnosed resistant hypertension (median age 52.02 years, range 42-72) underwent percutaneous catheter-based renal denervation of nerve terminals in renal arteries. Arterial angiography and procedure of ablation was performed by Symplicity catheters and generator provided by Ardian (currently Medtronic Inc., USA). Mean BP value before ablation was [mm Hg]: systolic 176.6, diastolic 100.28 and pulse pressure 73.4. After the procedure, reductions in the value of BP were reported [mm Hg]: systolic 154.8/152.54; diastolic 90.2/89.8, pulse pressure 64.66/62.73, respectively in nine-month and one-year follow-up. All results were statistically significant. No complications during one year observation were observed. Percutaneous renal artery ablation procedure effectively reduces systolic BP, diastolic BP, and pulse pressure. No vascular or renal complications in any of the patients were observed. The results of a Polish research group showed no significant differences compared to the results obtained in the international studies Symplicity I and Symplicity II.

How much do physician-entrepreneurs contribute to new medical devices?

PubMed

Smith, Sheryl Winston; Sfekas, Andrew

2013-05-01

As recent public and private initiatives have sought to increase the transparency of physician-industry financial relationships (including calls for restricting collaboration), it is important to understand the extent of physicians' contributions to new medical devices. We quantify the contribution of information from physician-founded startup companies to 170 premarket approval (PMA) applications filed by 4 large incumbent medical device manufacturers over the period 1978-2007. We ask: Are incumbents more likely to incorporate information from physician-founded firms than nonphysician-founded firms? We matched the text in 4 incumbent medical device firms' PMAs (Medtronic, Johnson & Johnson, Boston Scientific, and Guidant) to the text in patent applications of 118 startup companies that received investment from these incumbents between 1978 and 2007. We use a text-matching algorithm to quantify the information contribution from physician and nonphysician-founded startups to incumbent firms' PMAs. We analyze correlates of backward citations and degree of overlap between incumbents' PMAs and startups' patents using negative binomial and tobit regressions. On average, physician-founded companies account for 11% of the information in PMAs, compared with 4% from nonphysician-founded companies. Regression results show that incumbents are significantly more likely to cite physician-founded companies' patents and to incorporate them into new devices. Physicians are an important source of medical device innovation. The results suggest that restrictions on financial relationships between providers and industry, while potentially improving patients' trust, may result in reduced medical innovation if physicians found fewer startups or if incumbent firms reduce investments in physician-founded startups.

A randomised trial of high and low pressure level settings on an adjustable ventriculoperitoneal shunt valve for idiopathic normal pressure hydrocephalus: results of the Dutch evaluation programme Strata shunt (DEPSS) trial.

PubMed

Delwel, Ernst J; de Jong, Dirk A; Dammers, Ruben; Kurt, Erkan; van den Brink, Wimar; Dirven, Clemens M F

2013-07-01

In treating idiopathic normal pressure hydrocephalus (INPH) with a shunt there is always a risk of underdrainage or overdrainage. The hypothesis is tested whether patients treated using an adjustable valve preset at the highest opening pressure leads to comparable good clinical results with less subdural effusions than in a control group with an opening pressure preset at a low pressure level. A multicentre prospective randomised trial was performed on a total of 58 patients suspected of INPH. Thirty patients were assigned to (control) group 1 and received a Strata shunt (Medtronic, Goleta, USA) with the valve preset at a performance level (PL) of 1.0, while 28 patients were assigned to group 2 and received a Strata shunt with the valve preset at PL 2.5. In this group the PL was allowed to be lowered until improvement or radiological signs of overdrainage were met. Significantly more subdural effusions were observed in the improved patients of group 1. There was no statistically significant difference in improvement between both groups overall. On the basis of this multicentre prospective randomised trial it is to be recommended to treat patients with INPH with a shunt with an adjustable valve, preset at the highest opening pressure and lowered until clinical improvement or radiological signs of overdrainage occur although slower improvement and more shunt adjustments might be the consequence.

Hyperglycemia and glycemic variability are associated with the severity of sepsis in nondiabetic subjects.

PubMed

Preechasuk, Lukana; Suwansaksri, Nattakarn; Ipichart, Nantawan; Vannasaeng, Sathit; Permpikul, Chairat; Sriwijitkamol, Apiradee

2017-04-01

The purpose was to compare glucose variability (GV) obtained via continuous glucose monitoring between nondiabetic sepsis patients and healthy subjects and to seek associations between GV and sepsis severity in nondiabetic sepsis patients. Nondiabetic sepsis inpatients and healthy controls received a 72-hour continuous glucose monitoring (iPro2, Medtronic) postadmission and post-oral glucose tolerance test, respectively. The mean glucose level (MGL) along with GV represented by standard deviation (SD) and the mean amplitude of glycemic excursion (MAGE) were calculated at 24 and 72 hours. Sepsis severity was evaluated with the Sepsis-related Organ Failure Assessment Score (SOFA). MGL and GV in patients with SOFA ≥9 and <9 were compared. Thirty nondiabetic sepsis and 10 healthy subjects were recruited. No differences were found between groups except for higher patient age in sepsis patients. The MGL and MAGE 72h of sepsis patients were significantly higher than those of healthy subjects. MGL and GV 24h were higher in patients with SOFA ≥9 than in patients with SOFA <9 (MGL 24h 195±17 vs 139±27, P<.001; SD 24h 32 [28, 36] vs 19 [5, 58], P=.02; and MAGE 24h 94 [58, 153] vs 54 [16, 179], P=.01). Nondiabetic sepsis patients had higher MGL and GV values than healthy subjects. MGL and GV 24h were associated with sepsis severity. Copyright © 2016 Elsevier Inc. All rights reserved.

Safety of repetitive transcranial magnetic stimulation in patients with implanted cortical electrodes. An ex-vivo study and report of a case.

PubMed

Phielipp, Nicolás M; Saha, Utpal; Sankar, Tejas; Yugeta, Akihiro; Chen, Robert

2017-06-01

To evaluate the safety of repetitive transcranial magnetic stimulation (rTMS) in patients with implanted subdural cortical electrodes. We performed ex-vivo experiments to test the temperature, displacement and current induced in the electrodes with single pulse transcranial magnetic stimulation (TMS) from 10 to 100% of stimulator output and tested a typical rTMS protocol used in a clinical setting. We then used rTMS to the motor cortex to treat a patient with refractory post-herpetic neuralgia who had previously been implanted with a subdural motor cortical electrode for pain management. The rTMS protocol consisted of ten sessions of 2000 stimuli at 20Hz and 90% of resting motor threshold. The ex-vivo study showed an increase in the coil temperature of 2°C, a maximum induced charge density of 30.4μC/cm 2 /phase, and no electrode displacement with TMS. There was no serious adverse effect associated with rTMS treatment of the patient. Cortical tremor was observed in the intervals between trains of stimuli during one treatment session. TMS was safe in a patient with implanted Medtronic Resume II electrode (model 3587A) subdural cortical electrode. TMS may be used as a therapeutic, diagnostic or research tool in patients this type of with implanted cortical electrodes. Copyright © 2017 International Federation of Clinical Neurophysiology. Published by Elsevier B.V. All rights reserved.

The pros and cons of intraoperative CT scan in evaluation of deep brain stimulation lead implantation: A retrospective study

PubMed Central

Servello, Domenico; Zekaj, Edvin; Saleh, Christian; Pacchetti, Claudio; Porta, Mauro

2016-01-01

Background: Deep brain stimulation (DBS) is an established therapy for movement disorders, such as Parkinson's disease (PD), dystonia, and tremor. The efficacy of DBS depends on the correct lead positioning. The commonly adopted postoperative radiological evaluation is performed with computed tomography (CT) scan and/or magnetic resonance imaging (MRI). Methods: We conducted a retrospective study on 202 patients who underwent DBS from January 2009 to October 2013. DBS indications were PD, progressive supranuclear palsy, tremor, dystonia, Tourette syndrome, obsessive compulsive disorder, depression, and Huntington's disease. Preoperatively, all patients underwent brain MRI and brain CT scan with the stereotactic frame positioned. The lead location was confirmed intraoperatively with CT. The CT images were subsequently transferred to the Stealth Station Medtronic and merged with the preoperative planning. On the first or second day after, implantation we performed a brain MRI to confirm the correct position of the lead. Results: In 14 patients, leads were in suboptimal position after intraoperative CT scan positioning. The cases with alteration in the Z-axis were corrected immediately under fluoroscopic guidance. In all the 14 patients, an immediate repositioning was done. Conclusions: Based on our data, intraoperative CT scan is fast, safe, and a useful tool in the evaluation of the position of the implanted lead. It also reduces the patient's discomfort derived from the transfer of the patient from the operating room to the radiological department. However, intraoperative CT should not be considered as a substitute for postoperative MRI. PMID:27583182

Project Baiterek: A Patient Access Program to Improve Clinical Outcomes and Quality of Life in Children with Type 1 Diabetes in Kazakhstan.

PubMed

Muratalina, Aigul; Smith-Palmer, Jayne; Nurbekova, Akmaral; Abduakhassova, Gulmira; Zhubandykova, Leila; Roze, Stéphane; Karamalis, Manolis; Shamshatova, Gulzhakhan; Demessinov, Adi; D'Agostino, Nicola Dunne; Lynch, Peter; Yedigarova, Larisa; Klots, Motty; Valentine, William; Welsh, John; Kaufman, Francine

2015-09-01

Diabetes is a key driver in the rise of noncommunicable diseases globally. It causes expensive and burdensome short- and long-term complications, with both an economic and social impact. In many countries, however, access to care and disease management in type 1 diabetes is suboptimal, increasing the risk for complications. In 2011, Project Baiterek was initiated as a collaborative effort between the Kazakhstan Ministry of Health, industry (Medtronic Plc), local physicians, and the Diabetes Association of the Republic of Kazakhstan to enhance patient access to continuous subcutaneous insulin infusion (CSII) therapy. It was the first countrywide project to provide equity and universal access to insulin pump therapy among children with type 1 diabetes, increasing pump use from zero to two-thirds of this population in less than 3 years. The project also involved instigating longitudinal data collection, and long-term clinical outcomes continue to be monitored. Here, we provide an overview of the clinical, quality-of-life, and economic outcomes to date associated with providing CSII therapy to children with type 1 diabetes in Kazakhstan. Initial clinical data show that CSII therapy improved clinical outcomes and quality of life for patients entered into the program and that CSII therapy was cost-effective relative to multiple daily injection therapy. The positive outcomes of Project Baiterek provide a template for similar patient access programs in other settings, and its framework could be adapted to initiatives to change health care infrastructures and standards of care for other noncommunicable diseases. Copyright © 2015. Published by Elsevier Inc.

Diagnosis and therapy of atrial tachyarrhythmias in the dual chamber implantable cardioverter defibrillator.

PubMed

Dijkman, B; Wellens, H J

2000-11-01

Devices capable of monitoring and treating atrial tachyarrhythmias provide information about the natural history of the arrhythmias and potentially can influence their natural course by electrical therapy early after onset. Types of atrial arrhythmias and efficacy of device therapies were evaluated in 30 patients implanted with the Medtronic model 7250 Jewel AF implantable cardioverter defibrillator (ICD). All patients had structural heart disease and documented sustained ventricular and atrial arrhythmias (27 with atrial fibrillation [AF]) before implant. Twenty patients were taking amiodarone, and three were taking sotalol. During 20+/-10 months of follow-up, 600 atrial arrhythmia recurrences were documented in 50% of patients. AF was diagnosed in 19%, fast polymorphic atrial tachycardia (AT) in 20%, fast monomorphic AT in 57%, and slow AT in 4% of episodes. The two adaptive pacing therapies, burst and ramp, together with the 50-Hz burst, were successful in 57% of detected atrial arrhythmias. Burst and ramp were responsible for 49% and 50-Hz burst for 51% of successfully treated arrhythmias; 33% of the episodes terminated spontaneously. No ventricular proarrhythmia was observed due to atrial pacing therapies. In 30% of episodes, dual chamber pacing was required due to post termination bradycardia. Atrial arrhythmia recurrences in patients with dilated cardiomyopathy were not amenable to pacing therapies. Several aspects of atrial arrhythmia diagnosis, therapy, and documentation that are specific for functioning of the Jewel AF are discussed. Atrial arrhythmias in ICD patients with diseased hearts who are taking Class III antiarrhythmics frequently had longer cycle lengths than AF. Half of these arrhythmias could be terminated with pacing therapies; one third terminated spontaneously.

Measurements of RF heating during 3.0-T MRI of a pig implanted with deep brain stimulator.

PubMed

Gorny, Krzysztof R; Presti, Michael F; Goerss, Stephan J; Hwang, Sun C; Jang, Dong-Pyo; Kim, Inyong; Min, Hoon-Ki; Shu, Yunhong; Favazza, Christopher P; Lee, Kendall H; Bernstein, Matt A

2013-06-01

To present preliminary, in vivo temperature measurements during MRI of a pig implanted with a deep brain stimulation (DBS) system. DBS system (Medtronic Inc., Minneapolis, MN) was implanted in the brain of an anesthetized pig. 3.0-T MRI was performed with a T/R head coil using the low-SAR GRE EPI and IR-prepped GRE sequences (SAR: 0.42 and 0.39 W/kg, respectively), and the high-SAR 4-echo RF spin echo (SAR: 2.9 W/kg). Fluoroptic thermometry was used to directly measure RF-related heating at the DBS electrodes, and at the implantable pulse generator (IPG). For reference the measurements were repeated in the same pig at 1.5 T and, at both field strengths, in a phantom. At 3.0T, the maximal temperature elevations at DBS electrodes were 0.46 °C and 2.3 °C, for the low- and high-SAR sequences, respectively. No heating was observed on the implanted IPG during any of the measurements. Measurements of in vivo heating differed from those obtained in the phantom. The 3.0-T MRI using GRE EPI and IR-prepped GRE sequences resulted in local temperature elevations at DBS electrodes of no more than 0.46 °C. Although no extrapolation should be made to human exams and much further study will be needed, these preliminary data are encouraging for the future use 3.0-T MRI in patients with DBS. Copyright © 2013 Elsevier Inc. All rights reserved.

Design and in vivo evaluation of more efficient and selective deep brain stimulation electrodes

NASA Astrophysics Data System (ADS)

Howell, Bryan; Huynh, Brian; Grill, Warren M.

2015-08-01

Objective. Deep brain stimulation (DBS) is an effective treatment for movement disorders and a promising therapy for treating epilepsy and psychiatric disorders. Despite its clinical success, the efficiency and selectivity of DBS can be improved. Our objective was to design electrode geometries that increased the efficiency and selectivity of DBS. Approach. We coupled computational models of electrodes in brain tissue with cable models of axons of passage (AOPs), terminating axons (TAs), and local neurons (LNs); we used engineering optimization to design electrodes for stimulating these neural elements; and the model predictions were tested in vivo. Main results. Compared with the standard electrode used in the Medtronic Model 3387 and 3389 arrays, model-optimized electrodes consumed 45-84% less power. Similar gains in selectivity were evident with the optimized electrodes: 50% of parallel AOPs could be activated while reducing activation of perpendicular AOPs from 44 to 48% with the standard electrode to 0-14% with bipolar designs; 50% of perpendicular AOPs could be activated while reducing activation of parallel AOPs from 53 to 55% with the standard electrode to 1-5% with an array of cathodes; and, 50% of TAs could be activated while reducing activation of AOPs from 43 to 100% with the standard electrode to 2-15% with a distal anode. In vivo, both the geometry and polarity of the electrode had a profound impact on the efficiency and selectivity of stimulation. Significance. Model-based design is a powerful tool that can be used to improve the efficiency and selectivity of DBS electrodes.

Single transseptal big Cryoballoon pulmonary vein isolation using an inner lumen mapping catheter.

PubMed

Chun, Kr Julian; Bordignon, Stefano; Gunawardene, Melanie; Urban, Verena; Kulikoglu, Mehmet; Schulte-Hahn, Britta; Nowak, Bernd; Schmidt, Boris

2012-11-01

The single big cryoballon technique for pulmonary vein isolation (PVI) has been limited by the need for two transseptal punctures (TP). We therefore investigated feasibility and safety of a simplified approach using a single TP and a novel circumferential mapping catheter (CMC). Patients underwent 28-mm cryoballoon PVI using a single TP. The CMC (Achieve(©) Medtronic Inc., Minneapolis, MN, USA) served as (1) guidewire and (2) as a PV mapping tool. Primary endpoint was PVI without switching to a regular guidewire. Secondary endpoints included: (1) PV signal quality during freezing, (2) time to PVI, (3) classification of successful ablation technique, (4) complications, and (5) procedural data. A total of 32 patients (126 PVs) were studied (mean age: 62 ± 11 years, 24 males, left atrium: 40 ± 4 mm). The primary endpoint was achieved in 29/32 patients (91%) and 123/126 PVs (98%) with a procedure and fluoroscopy time of 126 ± 26 minutes and 18.9 ± 7.5 minutes, respectively. Real-time visualization of PVI could be observed in 61/126 (48%) PVs. Time to sustained PVI versus nonsustained PVI was 66 ± 56 seconds versus 129 ± 76 seconds (P < 0.001). One phrenic nerve palsy was observed. After a follow-up of 250 ± 84 days 23/32 patients (72%) remained in sinus rhythm. The "simplified single big cryoballoon" PVI strategy appears to be safe and feasible. However, real-time PV recording was achieved in <50% of PVs. Therefore, further catheter refinements are warranted. (PACE 2012; 35:1304-1311). ©2012, The Authors. Journal compilation ©2012 Wiley Periodicals, Inc.

Catheter Ablation of Focal Atrial Tachycardia Using Remote Magnetic Navigation.

PubMed

Webster, Mark; Pasupati, Sanjeevan; Lever, Nigel; Stiles, Martin

2018-05-01

This first-in-human study evaluated the safety and technical feasibility of the Tempo temporary cardiac pacing lead (BioTrace Medical), which includes a novel fixation mechanism and soft tip. Complications of temporary pacing leads include dislodgment, arrhythmias, and ventricular perforation. Temporary pacing applications have increased with transcatheter aortic valve replacement (TAVR) growth, for rapid pacing during balloon valvuloplasty (BAV) and valve deployment, and for periprocedural bradyarrhythmia support. Eligible patients required temporary pacing for TAVR, BAV, or electrophysiology (EP) procedures. Transthoracic echocardiograms were obtained at baseline and 24 hours after lead removal. Safety was defined as freedom from pericardial effusion requiring intervention or evidence of tamponade. Technical feasibility involved successful intracardiac delivery and pace capture. Additional evaluations included pacing threshold (PCT), rapid pacing, dislodgment, or sustained ventricular arrhythmias. Follow-up was to 30 days. Twenty-five patients (60% female; mean age, 64 ± 19 years) underwent 13 TAVRs (7 Sapien 3 valves [Edwards Lifesciences], 4 CoreValves [Medtronic], and 2 Lotus valves [Boston Scientific]), 11 EP procedures, and 1 BAV at two New Zealand centers from January 2016 to June 2016. Safety was met in all patients, with no device-related adverse events. Technical feasibility was achieved in 23 cases (92%); 2 patients had unsuitable anatomy. No patient had lead dislodgment or sustained ventricular arrhythmias, and the final procedural PCT was 0.7 ± 0.5 mA. Rapid pacing was successful in all cases. Five patients had successful postprocedural use up to 5 days. This first-in-human study demonstrates the safety and technical feasibility of the Tempo lead, providing stable periprocedural temporary pacing support.

A comparative effectiveness analysis of three continuous glucose monitors.

PubMed

Damiano, Edward R; El-Khatib, Firas H; Zheng, Hui; Nathan, David M; Russell, Steven J

2013-02-01

To compare three continuous glucose monitoring (CGM) devices in subjects with type 1 diabetes under closed-loop blood glucose (BG) control. Six subjects with type 1 diabetes (age 52 ± 14 years, diabetes duration 32 ± 14 years) each participated in two 51-h closed-loop BG control experiments in the hospital. Venous plasma glucose (PG) measurements (GlucoScout, International Biomedical) obtained every 15 min (2,360 values) were paired in time with corresponding CGM glucose (CGMG) measurements obtained from three CGM devices, the Navigator (Abbott Diabetes Care), the Seven Plus (DexCom), and the Guardian (Medtronic), worn simultaneously by each subject. Errors in paired PG-CGMG measurements and data reporting percentages were obtained for each CGM device. The Navigator had the best overall accuracy, with an aggregate mean absolute relative difference (MARD) of all paired points of 11.8 ± 11.1% and an average MARD across all 12 experiments of 11.8 ± 3.8%. The Seven Plus and Guardian produced aggregate MARDs of all paired points of 16.5 ± 17.8% and 20.3 ± 18.0%, respectively, and average MARDs across all 12 experiments of 16.5 ± 6.7% and 20.2 ± 6.8%, respectively. Data reporting percentages, a measure of reliability, were 76% for the Seven Plus and nearly 100% for the Navigator and Guardian. A comprehensive head-to-head-to-head comparison of three CGM devices for BG values from 36 to 563 mg/dL revealed marked differences in performance characteristics that include accuracy, precision, and reliability. The Navigator outperformed the other two in these areas.

Phrenic nerve paralysis during cryoballoon ablation for atrial fibrillation: a comparison between the first- and second-generation balloon.

PubMed

Casado-Arroyo, Ruben; Chierchia, Gian-Battista; Conte, Giulio; Levinstein, Moisés; Sieira, Juan; Rodriguez-Mañero, Moises; di Giovanni, Giacomo; Baltogiannis, Yannis; Wauters, Kristel; de Asmundis, Carlo; Sarkozy, Andrea; Brugada, Pedro

2013-09-01

Phrenic nerve palsy (PNP) is the most frequently observed complication during cryoballoon ablation (CB; Arctic Front, Medtronic, MN) occurring in roughly 7%-9% of the cases. The new second-generation cryoballoon ablation Arctic Front Advance (CB-A) (Arctic Front) has recently been launched in the market. To evaluate the incidence of right PNP with the new CB-A in comparison with the first-generation balloon in a series of consecutive patients that underwent pulmonary vein isolation with this modality. The study was designed as an observational study with a prospective follow-up. In total, 121 consecutive patients were included: 80 patients with the CB (group 1) and 41 with the CB-A (group 2). Mean procedural times, fluoroscopic times, and time to pulmonary vein isolation documented by real-time recordings were significantly lower in group 2 (P ≤ .05). The occurrence of PNP was significantly higher in group 2 (6.25% [5 of 80] in group 1 vs 19.5% [8 of 41] in group 2; P = .033). At 7 months, PNP persisted in 1 (2.5%) patient in the CB-A group. Right PNP seems to occur in a significantly larger number of patients with the second-generation CB-A. However, this complication is reversible in nearly all cases on short-term follow-up. More refined phrenic nerve monitoring during right-sided pulmonary vein ablation and less vigorous wedging maneuvers in the pulmonary vein ostia might significantly reduce the occurrence of this complication. © 2013 Heart Rhythm Society. All rights reserved.

Relation between calcium burden, echocardiographic stent frame eccentricity and paravalvular leakage after corevalve transcatheter aortic valve implantation.

PubMed

Di Martino, Luigi F M; Soliman, Osama I I; van Gils, Lennart; Vletter, Wim B; Van Mieghem, Nicolas M; Ren, Ben; Galema, Tjebbe W; Schultz, Carl; de Jaegere, Peter P T; Di Biase, Matteo; Geleijnse, Marcel L

2017-06-01

Paravalvular aortic leakage (PVL) after transcatheter aortic valve implantation (TAVI) is a complication with potentially severe consequences. The relation between native aortic root calcium burden, stent frame eccentricity and PVL was not studied before. Two-hundred-and-twenty-three consecutive patients with severe aortic stenosis who underwent TAVI with a Medtronic CoreValve System© and who had available pre-discharge transthoracic echocardiography were studied. Echocardiographic stent inflow frame eccentricity was defined as major-minor diameter in a short-axis view >2 mm. PVL was scored according to the updated Valve Academic Research Consortium (VARC-2) recommendations. In a subgroup of 162 (73%) patients, the calcium Agatston score was available. Stent frame eccentricity was seen in 77 (35%) of patients. The correlation between the Agatston score and stent frame eccentricity was significant (ρ = 0.241, P = 0.003). Paravalvular leakage was absent in 91 cases (41%), mild in 67 (30%), moderate in 51 (23%), and severe in 14 (6%) cases. The correlation between stent frame eccentricity and PVL severity was significant (ρ = 0.525, P < 0.0001). There was a relation between particular eccentric stent frame shapes and the site of PVL. Calcification of the aortic annulus is associated with a subsequent eccentric shape of the CoreValve prosthesis. This eccentric shape results in more PVL, with the localization of PVL related to the shape of stent frame eccentricity. Published on behalf of the European Society of Cardiology. All rights reserved. © The Author 2017. For permissions, please email: journals.permissions@oup.com.

Screw Placement Accuracy and Outcomes Following O-Arm-Navigated Atlantoaxial Fusion: A Feasibility Study.

PubMed

Smith, Jacob D; Jack, Megan M; Harn, Nicholas R; Bertsch, Judson R; Arnold, Paul M

2016-06-01

Study Design Case series of seven patients. Objective C2 stabilization can be challenging due to the complex anatomy of the upper cervical vertebrae. We describe seven cases of C1-C2 fusion using intraoperative navigation to aid in the screw placement at the atlantoaxial (C1-C2) junction. Methods Between 2011 and 2014, seven patients underwent posterior atlantoaxial fusion using intraoperative frameless stereotactic O-arm Surgical Imaging and StealthStation Surgical Navigation System (Medtronic, Inc., Minneapolis, Minnesota, United States). Outcome measures included screw accuracy, neurologic status, radiation dosing, and surgical complications. Results Four patients had fusion at C1-C2 only, and in the remaining three, fixation extended down to C3 due to anatomical considerations for screw placement recognized on intraoperative imaging. Out of 30 screws placed, all demonstrated minimal divergence from desired placement in either C1 lateral mass, C2 pedicle, or C3 lateral mass. No neurovascular compromise was seen following the use of intraoperative guided screw placement. The average radiation dosing due to intraoperative imaging was 39.0 mGy. All patients were followed for a minimum of 12 months. All patients went on to solid fusion. Conclusion C1-C2 fusion using computed tomography-guided navigation is a safe and effective way to treat atlantoaxial instability. Intraoperative neuronavigation allows for high accuracy of screw placement, limits complications by sparing injury to the critical structures in the upper cervical spine, and can help surgeons make intraoperative decisions regarding complex pathology.

Discovering your authentic leadership.

PubMed

George, Bill; Sims, Peter; McLean, Andrew N; Mayer, Diana

2007-02-01

The ongoing problems in business leadership over the past five years have underscored the need for a new kind of leader in the twenty-first century: the authentic leader. Author Bill George, a Harvard Business School professor and the former chairman and CEO of Medtronic, and his colleagues, conducted the largest leadership development study ever undertaken. They interviewed 125 business leaders from different racial, religious, national, and socioeconomic backgrounds to understand how leaders become and remain authentic. Their interviews showed that you do not have to be born with any particular characteristics or traits to lead. You also do not have to be at the top of your organization. Anyone can learn to be an authentic leader. The journey begins with leaders understanding their life stories. Authentic leaders frame their stories in ways that allow them to see themselves not as passive observers but as individuals who learn from their experiences. These leaders make time to examine their experiences and to reflect on them, and in doing so they grow as individuals and as leaders. Authentic leaders also work hard at developing self-awareness through persistent and often courageous self-exploration. Denial can be the greatest hurdle that leaders face in becoming self-aware, but authentic leaders ask for, and listen to, honest feedback. They also use formal and informal support networks to help them stay grounded and lead integrated lives. The authors argue that achieving business results over a sustained period of time is the ultimate mark of authentic leadership. It may be possible to drive short-term outcomes without being authentic, but authentic leadership is the only way to create long-term results.

Back pain: a real target for spinal cord stimulation?

PubMed

Rigoard, Philippe; Delmotte, Alexandre; D'Houtaud, Samuel; Misbert, Lorraine; Diallo, Bakari; Roy-Moreau, Aline; Durand, Sylvain; Royoux, Solène; Giot, Jean-Philippe; Bataille, Benoit

2012-03-01

Failed back surgery syndrome represents one of the most frequent etiologies of chronic back pain and is a major public health issue. Neurostimulation has currently not been validated in the treatment of back pain because of technological limitations in implantable spinal cord stimulation (SCS) systems. New-generation leads using several columns of stimulation can generate longitudinal and/or transverse stimulation fields into the spinal cord. To investigate, through extensive stimulation testing, the capacity of multicolumn tripolar leads to achieve back territory paresthesia coverage in refractory failed back surgery syndrome patients. Eleven patients implanted with a 16-contact spinal cord stimulation lead (Specify 5-6-5, Medtronic Inc) were assessed with a systematic exploration of 43 selected stimulation configurations to generate bilateral back paresthesia in addition to leg territory coverage. The tripolar lead successfully generated paresthesia in both bilateral back and leg territories in 9 patients (81.8%). Success rates of multicolumn stimulation patterns were significantly higher than for longitudinal configurations for lombodorsal paresthesia coverage. Six months after implantation, significant pain relief was obtained compared with preoperative evaluation for global pain (Visual Analog Scale, 2.25 vs 8.2 preoperatively; P < .05), leg pain (Visual Analog Scale, 0.5 vs 7.6 preoperatively; P < .05), and back pain (Visual Analog Scale, 1.5 vs 7.8 preoperatively; P < .05). These results suggest that multicolumn leads can reliably generate back pain coverage and favor pain relief outcomes. This may lead physicians to reconsider new indications for spinal cord stimulation. Expanding neurostimulation perspectives to intractable back pain syndromes could become realistic in the near future.

Endovascular Treatment of Posterior Cerebral Artery Aneurysms With Flow Diversion: Case Series and Systematic Review.

PubMed

Wallace, Adam N; Grossberg, Jonathan A; Almandoz, Josser E Delgado; Kamran, Mudassar; Roy, Anil K; Kayan, Yasha; Austin, Matthew J; Howard, Brian M; Moran, Christopher J; Cawley, C Michael; Cross, DeWitte T; Dion, Jacques E; Kansagra, Akash P; Osbun, Joshua W

2018-03-08

Flow diversion of posterior cerebral artery (PCA) aneurysms has not been widely reported, possibly owing to concerns regarding parent vessel size and branch vessel coverage. To examine the safety and effectiveness of PCA aneurysm flow diverter treatment. Retrospective review of PCA aneurysms treated with the Pipeline Embolization Device (PED; Medtronic Inc, Dublin, Ireland) at 3 neurovascular centers, including periprocedural complications and clinical and angiographic outcomes. Systematic review of the literature identified published reports of PCA aneurysms treated with flow diversion. Rates of aneurysm occlusion and complications were calculated, and outcomes of saccular and fusiform aneurysm treatments were compared. Ten PCA aneurysms in 9 patients were treated with the PED. There were 2 intraprocedural thromboembolic events (20%), including 1 symptomatic infarction and 1 delayed PED thrombosis. Eight of 10 patients returned to or improved from their baseline functional status. Complete aneurysm occlusion with parent vessel preservation was achieved in 75% (6/8) of cases at mean follow-up of 16.7 mo. Eleven of 12 (92%) major branch vessels covered by a PED remained patent. Including the present study, systematic review of 15 studies found a complete aneurysm occlusion rate of 88% (30/34) and complication rate of 26% (10/38), including 5 symptomatic ischemic strokes (13%; 5/38). Fusiform aneurysms more frequently completely occluded compared with saccular aneurysms (100% vs 70%; P = .03) but were associated with a higher complication rate (43% vs 9%; P = .06). The safety and effectiveness profile of flow diverter treatment of PCA aneurysms may be acceptable in select cases.

Magnetic resonance imaging-guided focused laser interstitial thermal therapy for subinsular metastatic adenocarcinoma: technical case report.

PubMed

Hawasli, Ammar H; Ray, Wilson Z; Murphy, Rory K J; Dacey, Ralph G; Leuthardt, Eric C

2012-06-01

To describe the novel use of the AutoLITT System (Monteris Medical, Winnipeg, Manitoba, Canada) for focused laser interstitial thermal therapy (LITT) with intraoperative magnetic resonance imaging (MRI) and stereotactic image guidance for the treatment of metastatic adenocarcinoma in the left insula. The patient was a 61-year-old right-handed man with a history of metastatic adenocarcinoma of the colon. He had previously undergone resection of multiple lesions, Gamma Knife radiosurgery, and whole-brain radiation. Despite treatment of a left insular tumor, serial imaging revealed that the lesion continued to enlarge. Given the refractory nature of this tumor to radiation and the deep-seated location, the patient elected to undergo LITT treatment. The center of the lesion and entry point on the scalp were identified with STEALTH (Medtronic, Memphis, Tennessee) image-guided navigation. The AXiiiS Stereotactic Miniframe (Monteris Medical) for the LITT system was secured onto the skull, and a trajectory was defined to achieve access to the centroid of the tumor. After a burr hole was made, a gadolinium template probe was inserted into the AXiiiS base. The trajectory was confirmed via an intraoperative MRI, and the LITT probe driver was attached to the base and CO2-cooled, side-firing laser LITT probe. The laser was activated and thermometry images were obtained. Two trajectories, posteromedial and anterolateral, produced satisfactory tumor ablation. LITT with intraoperative MRI and stereotactic image guidance is a newly available, minimally invasive, and therapeutically viable technique for the treatment of deep seated brain tumors.

The new generation polestar n20 for conventional neurosurgical operating rooms: a preliminary report.

PubMed

Ntoukas, Vasileios; Krishnan, Rene; Seifert, Volker

2008-03-01

The objective of this work is to present the preliminary clinical experience we acquired in using the new PoleStar generation, N20 (Medtronic Navigation, Louisville, CO), in a modified conventional operating room. PoleStar N20 is a 0.15-T, intraoperative scanner combined with both an integrated optical and a magnetic resonance imaging tracking scanner. All standard imaging modes, such as T1, T2, and fluid-attenuated inversion recovery, are available through the magnet. To shield the operating room from radiofrequency interference, a Faraday cage was constructed using a conductive metal mesh installed under the wall decoration. Sixty-one patients, most of whom had gliomas or pituitary adenomas, underwent intraoperative magnetic resonance imaging in our clinic. The extent of resection and the surgical consequences of intraoperative imaging were analyzed. The image quality for T1-weighted, gadolinium-enhanced tumors was sufficiently good to enable us to evaluate the extent of tumor resection, whereas the T2-weighted image quality must be improved. New technologies, such as high-temperature superconductive coils and ultra-small super-paramagnetic iron particles, e.g., ferumoxtran-10, can lead to a dramatic improvement in image quality, heralding the commencement of the widespread use of intraoperative magnetic resonance imaging. The acquisition of the PoleStar N20 opened new horizons in the treatment of our patients. This novel, compact, intraoperative magnetic resonance imaging scanner can be installed in a standard operating room without major modifications. Standard surgical instruments can be used. Intraoperative magnetic resonance imaging provided valuable information that allowed intraoperative modification of the surgical strategy.

Renal sympathetic denervation in uncontrolled arterial hypertension after successful repair for aortic coarctation.

PubMed

Lurz, Philipp; Okon, Thomas; Riede, Thomas; Wagner, Robert; Schuler, Gerhard; Daehnert, Ingo; Desch, Steffen

2016-01-01

Uncontrolled arterial hypertension is a frequent problem after successful repair of CoA and has been attributed to increased central sympathetic drive as well as a blunted baroreceptor reflex. RSD is a promising therapy to reduce central sympathetic drive and improve baroreflex sensitivity. 8 patients (age: 27±6 years) with previous surgical and/or percutaneous repair of CoA, absence of any relevant restenosis (invasive gradient across the site of previous treatment 3±4 mmHg) and resistant arterial hypertension (daytime SBP≥140 mmHg on 24 hour ambulatory blood pressure measurements [ABPM] in spite of the concurrent use of 3 antihypertensive agents of different classes or intolerance to BP medications) were included. Bilateral RSD was performed using the Symplicity Flex™ catheter (Medtronic, MN, USA). RSD was successful in all patients with no procedural complications and no evidence for renal artery stenosis 6 months post procedure. From baseline to 6 month follow-up, RSD was followed by a significant reduction in average daytime systolic BP (150.4±7.8 to 143.1±8.0 mmHg; p=0.0117) as well as systolic BP throughout 24 h (146.8±7.3 vs. 140.5±7.8, p=0.04). The BP reductions observed in these patients justify engaging in a larger clinical trial on the efficacy of RSD in this specific type of secondary hypertension and bares the hope that RSD might extend the currently very limited armory against arterial hypertension in young adults with previous repair of CoA. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

Bioprosthetic Valve Fracture to Facilitate Transcatheter Valve-in-Valve Implantation.

PubMed

Allen, Keith B; Chhatriwalla, Adnan K; Cohen, David J; Saxon, John T; Aggarwal, Sanjeev; Hart, Anthony; Baron, Suzanne; Davis, J Russell; Pak, Alex F; Dvir, Danny; Borkon, A Michael

2017-11-01

Valve-in-valve transcatheter aortic valve replacement is less effective in small surgical bioprostheses. We evaluated the feasibility of bioprosthetic valve fracture with a high-pressure balloon to facilitate valve-in-valve transcatheter aortic valve replacement. In vitro bench testing on aortic tissue valves was performed on 19-mm and 21-mm Mitroflow (Sorin, Milan, Italy), Magna and Magna Ease (Edwards Lifesciences, Irvine, CA), Trifecta and Biocor Epic (St. Jude Medical, Minneapolis, MN), and Hancock II and Mosaic (Medtronic, Minneapolis, MN). High-pressure balloons Tru Dilation, Atlas Gold, and Dorado (C.R. Bard, Murray Hill, NJ) were used to determine which valves could be fractured and at what pressure fracture occurred. Mitroflow, Magna, Magna Ease, Mosaic, and Biocor Epic surgical valves were successfully fractured using high-pressures balloon 1 mm larger than the labeled valve size whereas Trifecta and Hancock II surgical valves could not be fractured. Only the internal valve frame was fractured, and the sewing cuff was never disrupted. Manufacturer's rated burst pressures for balloons were exceeded, with fracture pressures ranging from 8 to 24 atmospheres depending on the surgical valve. Testing further demonstrated that fracture facilitated the expansion of previously constrained, underexpanded transcatheter valves (both balloon and self-expanding) to the manufacturer's recommended size. Bench testing demonstrates that the frame of most, but not all, bioprosthetic surgical aortic valves can be fractured using high-pressure balloons. The safety of bioprosthetic valve fracture to optimize valve-in-valve transcatheter aortic valve replacement in small surgical valves requires further clinical investigation. Copyright © 2017 The Society of Thoracic Surgeons. Published by Elsevier Inc. All rights reserved.

DUrable polymer-based sTent CHallenge of Promus ElemEnt versus ReSolute integrity (DUTCH PEERS): rationale and study design of a randomized multicenter trial in a Dutch all-comers population.

PubMed

Tandjung, Kenneth; Basalus, Mounir W Z; Sen, Hanim; Jessurun, Gillian A J; Danse, Peter W; Stoel, Martin; Linssen, Gerard C M; Derks, Anita; van Loenhout, Ton T; Nienhuis, Mark B; Hautvast, Raymond W M; von Birgelen, Clemens

2012-04-01

Drug-eluting stents (DES) are increasingly used for the treatment of coronary artery disease. An optimized DES performance is desirable to successfully treat various challenging coronary lesions in a broad population of patients. In response to this demand, third-generation DES with an improved deliverability were developed. Promus Element (Boston Scientific, Natick, MA) and Resolute Integrity (Medtronic Vascular, Santa Rosa, CA) are 2 novel third-generation DES for which limited clinical data are available. Accordingly, we designed the current multicenter study to investigate in an all-comers population whether the clinical outcome is similar after stenting with Promus Element versus Resolute Integrity. DUTCH PEERS is a multicenter, prospective, single-blinded, randomized trial in a Dutch all-comers population. Patients with all clinical syndromes who require percutaneous coronary interventions with DES implantation are eligible. In these patients, the type of DES implanted will be randomized in a 1:1 ratio between Resolute Integrity versus Promus Element. The trial is powered based on a noninferiority hypothesis. For each stent arm, 894 patients will be enrolled, resulting in a total study population of 1,788 patients. The primary end point is the incidence of target vessel failure at 1-year follow-up. DUTCH PEERS is the first randomized multicenter trial with a head-to-head comparison of Promus Element and Resolute Integrity to investigate the safety and efficacy of these third-generation DES. Copyright © 2012 Mosby, Inc. All rights reserved.

Beam Profile Disturbances from Implantable Pacemakers or Implantable Cardioverter-Defibrillator Interactions

DOE Office of Scientific and Technical Information (OSTI.GOV)

Gossman, Michael S., E-mail: mgossman@tsrcc.com; Comprehensive Heart and Vascular Associates, Heart and Vascular Center, Ashland, KY; Medtronic, Inc., External Research Program, Mounds View, MN

2011-01-01

The medical community is advocating for progressive improvement in the design of implantable cardioverter-defibrillators and implantable pacemakers to accommodate elevations in dose limitation criteria. With advancement already made for magnetic resonance imaging compatibility in some, a greater need is present to inform the radiation oncologist and medical physicist regarding treatment planning beam profile changes when such devices are in the field of a therapeutic radiation beam. Treatment plan modeling was conducted to simulate effects induced by Medtronic, Inc.-manufactured devices on therapeutic radiation beams. As a continuation of grant-supported research, we show that radial and transverse open beam profiles of amore » medical accelerator were altered when compared with profiles resulting when implantable pacemakers and cardioverter-defibrillators are placed directly in the beam. Results are markedly different between the 2 devices in the axial plane and the sagittal planes. Vast differences are also presented for the therapeutic beams at 6-MV and 18-MV x-ray energies. Maximum changes in percentage depth dose are observed for the implantable cardioverter-defibrillator as 9.3% at 6 MV and 10.1% at 18 MV, with worst distance to agreement of isodose lines at 2.3 cm and 1.3 cm, respectively. For the implantable pacemaker, the maximum changes in percentage depth dose were observed as 10.7% at 6 MV and 6.9% at 18 MV, with worst distance to agreement of isodose lines at 2.5 cm and 1.9 cm, respectively. No differences were discernible for the defibrillation leads and the pacing lead.« less

Clinical evaluation of pacemaker automatic capture management and atrioventricular interval extension algorithm.

PubMed

Chen, Ke-ping; Xu, Geng; Wu, Shulin; Tang, Baopeng; Wang, Li; Zhang, Shu

2013-03-01

The present study was to assess the accuracy of automatic atrial and ventricular capture management (ACM and VCM) in determining pacing threshold and the performance of a second-generation automatic atrioventricular (AV) interval extension algorithm for reducing unnecessary ventricular pacing. A total of 398 patients at 32 centres who received an EnPulse dual-chamber pacing/dual-chamber adaptive rate pacing pacemaker (Medtronic, Minneapolis, MN, USA) were enrolled. The last amplitude thresholds as measured by ACM and VCM prior to the 6-month follow-up were compared with manually measured thresholds. Device diagnostics were used to evaluate ACM and VCM and the percentage of ventricular pacing with and without the AV extension algorithm. Modelling was performed to assess longevity gains relating to the use of automaticity features. Atrial and ventricular capture management performed accurately and reliably provided complete capture management in 97% of studied patients. The AV interval extension algorithm reduced the median per cent of right ventricular pacing in patients with sinus node dysfunction from 99.7 to 1.5% at 6-month follow-up and in patients with intermittent AV block (excluding persistent 3° AV block) from 99.9 to 50.2%. On the basis of validated modelling, estimated device longevity could potentially be extended by 1.9 years through the use of the capture management and AV interval extension features. Both ACM and VCM features reliably measured thresholds in nearly all patients; the AV extension algorithm significantly reduced ventricular pacing; and the use of pacemaker automaticity features potentially extends device longevity.

Comparison of the 9-month intra-stent conditions and 2-year clinical outcomes after Resolute zotarolimus-eluting stent implantation between 3-month and standard dual antiplatelet therapy.

PubMed

Fujimoto, Wataru; Sawada, Takahiro; Toba, Takayoshi; Takahashi, Yu; Miyata, Taishi; Oishi, Shogo; Osue, Tsuyoshi; Onishi, Tetsuari; Takaya, Tomofumi; Shimane, Akira; Taniguchi, Yasuyo; Kawai, Hiroya; Yasaka, Yoshinori

2018-07-01

The use of short-duration dual antiplatelet therapy (DAPT) remains controversial. To investigate efficacy and safety of short-duration DAPT, we performed a detailed comparison of intra-stent conditions by optical coherence tomography (OCT) after second-generation drug-eluting stent implantation with short-term and standard DAPT. Eighty-two consecutive patients with stable angina pectoris who received Resolute zotarolimus-eluting stents (R-ZESs; Medtronic Cardiovascular, Santa Rosa, CA, USA) were enrolled. Patients were assigned to 3-month (3M group: 41 patients) and standard (standard group: 41 patients) DAPT. In the 3M group, clopidogrel was discontinued 3 months after stent implantation. In the standard group, DAPT was maintained until follow-up OCT. At 9 months, neointimal proliferation was significantly larger in the 3M group, but there were no significant between-group differences in the proportion of uncovered and malapposed strut. The prevalence of abnormal intra-stent tissue (AIT) at 9 months was equivalent between groups. A multiple regression analysis revealed malapposition at 9 months as the strongest independent predictor of AIT at 9 months, and the prevalence of AIT was not associated with DAPT duration. Over 2 years, cardiac events were equal between groups; however, major bleeding was higher tendency in the standard group than in the 3M group. This OCT study indicated that reducing DAPT's duration may provide acceptable arterial healing in patients with implanted R-ZESs. Copyright © 2018 Japanese College of Cardiology. Published by Elsevier Ltd. All rights reserved.

Transcatheter closure of a sinus venosus atrial septal defect using 3D printing and image fusion guidance.

PubMed

Thakkar, Akanksha N; Chinnadurai, Ponraj; Breinholt, John P; Lin, C Huie

2018-06-13

A 63-year-old man with cirrhosis, hepatocellular carcinoma, and coagulopathy was diagnosed with a sinus venosus atrial septal defect (ASD) and partial anomalous pulmonary venous return (PAPVR) of the right upper pulmonary vein (RUPV). Transcatheter repair by positioning a stent graft in the superior vena cava was planned. Based on three-dimensional (3D) reconstruction of gated cardiac CTA, a 28 mm × 7 cm Endurant II ® aortic extension stent graft (Medtronic, MN) was chosen. A 3D model printed from the CTA was used to simulate device deployment, demonstrating successful exclusion of the sinus venosus ASD with return of the RUPV to the left atrium (LA). Post simulation, the 3D model was used for informed consent. The patient was then taken to the hybrid operating room. On-table cone beam CT was performed and registered with the CTA images. This enabled overlay of 3D regions of interest to live 2D fluoroscopy. The stent graft was then deployed using 3D regions of interest for guidance. Hemodynamics and angiography demonstrated successful exclusion of the sinus venosus ASD and unobstructed return of RUPV to the LA. This is the first report of comprehensive use of contemporary imaging for planning, simulation, patient consent, and procedural guidance for patient-centered complex structural intervention in repair of sinus venosus ASD with PAPVR. We propose this as a process model for continued innovation in structural interventions. © 2018 The Authors Catheterization and Cardiovascular Interventions Published by Wiley Periodicals, Inc.

Direct transcatheter aortic valve implantation with self-expandable bioprosthesis: feasibility and safety.

PubMed

Fiorina, Claudia; Maffeo, Diego; Curello, Salvatore; Lipartiti, Felicia; Chizzola, Giuliano; D'Aloia, Antonio; Adamo, Marianna; Mastropierro, Rosy; Gavazzi, Emanuele; Ciccarese, Camilla; Chiari, Ermanna; Ettori, Federica

2014-06-01

Balloon valvuloplasty has been considered a mandatory step of the transcatheter aortic valve implantation (TAVI), although it is not without risk. The aim of this work was to evaluate the feasibility and safety of TAVI performed without pre-dilation (direct TAVI) of the stenosed aortic valve. Between June 2012 and June 2013, 55 consecutive TAVI performed without pre-dilation at our institution using the self-expandable CoreValve prosthesis (Medtronic, Minneapolis, MN) were analyzed and compared with 45 pre-dilated TAVI performed the previous year. Inclusion criteria were a symptomatic and severe aortic stenosis. Exclusion criteria were defined as presence of pure aortic regurgitation, degenerated surgical bioprosthesis or bicuspid aortic valve and prior procedure of balloon aortic valvuloplasty performed as a bridge to TAVI. High-burden calcification in the device landing zone, assessed by CT scan, was found in most of the patients. The valve size implanted was similar in both groups. Device success was higher in direct TAVI (85%vs.64%,p=0.014), mostly driven by a significant lower incidence of paravalvular leak (PVL≥2;9%vs.33%,p=0.02). Safety combined end point at 30 days was similar in both groups. Compared to TAVI with pre-dilation, direct TAVI is feasible regardless of the presence of bulky calcified aortic valve and the valve size implanted. Device success was higher in direct TAVI, mostly driven by a lower incidence of paravalvular leak. Safety at 30 days was similar in two groups. Copyright © 2014 Elsevier Inc. All rights reserved.

Phrenic nerve stimulation during neck dissection for advanced thyroid cancer involving level IV: is it worth doing it?

PubMed

Duque, Carlos S; Dueñas, Juan P; Marulanda, Marcela; Pérez, Diana; Londoňo, Andres; Roy, Soham; Khadem, Mai Al

2017-03-01

During thyroidectomy and neck dissection surgery for advanced or recurrent metastatic thyroid cancer under intraoperative monitoring, we used the available technology to assess the feasibility of such an intervention to monitor those patients with phrenic nerves at risk. A retrospective review of patients operated on from January 2009 to December 2015 by a single surgeon (CSD) was conducted. Patients who had neck and mediastinal dissection, with or without total thyroidectomy, due to advanced or recurrent metastatic disease to the neck were selected. The procedures were done under intraoperative nerve monitoring using nerve monitoring systems (NIM 2.0 or 3.0; Medtronic, Jacksonville, FL, USA). A total of 19 patients were included in the study, with a mean age of 57.6 years ± 16.3 and a male/female ratio of 10:9. Overall, all patients had an intact phrenic nerve at the conclusion of the surgery. One patient had an aggressive tumor that precluded sacrifice of the left recurrent laryngeal nerve and ipsilateral thoracic duct. The procedure was complicated by a temporary impairment of the diaphragm contraction with intraoperative nerve monitoring as well as a chyle fistula. This was due to the manipulation of the tissue surrounding the phrenic nerve. Intraoperative nerve monitoring of the phrenic nerve offers the surgeon a "potential" method of ensuring phrenic nerve integrity in cases of advanced thyroid cancers with gross level IV metastatic disease. Further prospective studies are needed to assess the risks of this intervention and evaluate the method of recording diaphragm contraction movement.

Time until diagnosis of clinical events with different remote monitoring systems in Implantable Cardioverter-Defibrillator patients.

PubMed

Söth-Hansen, Malene; Witt, Christoffer Tobias; Rasmussen, Mathis; Kristensen, Jens; Gerdes, Christian; Nielsen, Jens Cosedis

2018-05-24

Remote monitoring (RM) is an established technology integrated into routine follow-up of patients with implantable cardioverter-defibrillator (ICD). Current RM systems differ according to transmission frequency and alert definition. We aimed to compare time difference between detection and acknowledgement of clinically relevant events between four RM systems. We analyzed time delay between detection of ventricular arrhythmic and technical events by the ICD and acknowledgement by hospital staff in 1.802 consecutive patients followed with RM during September 2014 - August 2016. Devices from Biotronik (BIO, n=374), Boston Scientific (BSC, n=196), Medtronic (MDT, n=468) and St Jude Medical (SJM, n=764) were included. We identified all events from RM webpages and their acknowledgement with RM or at in-clinic follow-up. Events occurring during weekends were excluded. We included 3.472 events. Proportion of events acknowledged within 24 hours was 72%, 23%, 18% and 65% with BIO, BSC, MDT and SJM, respectively, with median times of 13, 222, 163 and 18 hours from detection to acknowledgement (p<0.001 for both comparisons between manufacturers). Including only events transmitted as alerts by RM, 72%, 68%, 61% and 65% for BIO, BSC, MDT and SJM, respectively were acknowledged within 24 hours. Variation in time to acknowledgement of ventricular tachyarrhythmia episodes not treated with shock therapy was the primary cause for the difference between manufacturers. Significant and clinically relevant differences in time delay from event detection to acknowledgement exist between RM systems. Varying definitions of which events RM transmits as alerts are important for the differences observed. Copyright © 2018. Published by Elsevier Inc.

Supraorbital Keyhole Craniotomy for Basilar Artery Aneurysms: Accounting for the "Cliff" Effect.

PubMed

Stamates, Melissa M; Wong, Andrew K; Bhansali, Anita; Wong, Ricky H

2017-04-01

Treatment of basilar artery aneurysms is challenging. While endovascular techniques have dominated, there still remain circumstances where open surgical clipping is required or preferred. Minimally invasive "keyhole" approaches are being used more frequently to provide the durability of surgical clipping with a lower morbidity profile; however, careful patient selection is required. The supraorbital "keyhole" approach has been described for the treatment of basilar artery aneurysms, but careful assessment of the basilar exposure is necessary to ensure proper visualization of the aneurysm and ability to obtain proximal vascular control. Various methods of estimating the basilar artery exposure in this approach have been described, including the anterior skull base line and the posterior clinoid line, but both are unreliable and inaccurate. To propose a new method, the orbital roof-dorsum line, to simply and accurately predict the basilar artery exposure. CT angiograms for 20 consecutive unique patients were analyzed to obtain the anterior skull base line, posterior clinoid line, and the orbital roof-dorsum line. CT angiograms were then loaded onto a Stealth neuronavigation system (Medtronic, Minneapolis, Minnesota) to obtain "true" visualization lengths. A case illustration is presented. Pairwise comparison tests demonstrated that both the anterior skull base and the posterior clinoid estimation lines differed significantly from the "true"  value ( P < .0001). Our orbital roof-dorsum estimation provided results that accurately predicted the "true" value ( P = .71). The orbital roof-dorsum line provides a simple and reliable method of estimating basilar artery exposure and should be used whenever considering patients for surgical clipping by this approach. Copyright © 2017 by the Congress of Neurological Surgeons

Measurements of RF Heating during 3.0T MRI of a Pig Implanted with Deep Brain Stimulator

PubMed Central

Gorny, Krzysztof R; Presti, Michael F; Goerss, Stephan J; Hwang, Sun C; Jang, Dong-Pyo; Kim, Inyong; Shu, Yunhong; Favazza, Christopher P; Lee, Kendall H; Bernstein, Matt A

2012-01-01

Purpose To present preliminary, in vivo temperature measurements during MRI of a pig implanted with a deep brain stimulation (DBS) system. Materials and Methods DBS system (Medtronic Inc., Minneapolis, MN) was implanted in the brain of an anesthetized pig. 3.0T MRI was performed with a T/R head coil using the low-SAR GRE EPI and IR-prepped GRE sequences (SAR: 0.42 W/kg and 0.39 W/kg, respectively), and the high-SAR 4-echo RF spin echo (SAR: 2.9 W/kg). Fluoroptic thermometry was used to directly measure RF-related heating at the DBS electrodes, and at the implantable pulse generator (IPG). For reference the measurements were repeated in the same pig at 1.5T and, at both field strengths, in a phantom. Results At 3.0T, the maximal temperature elevations at DBS electrodes were 0.46 °C and 2.3 °C, for the low- and high-SAR sequences, respectively. No heating was observed on the implanted IPG during any of the measurements. Measurements of in-vivo heating differed from those obtained in the phantom. Conclusion The 3.0T MRI using GRE EPI and IR-prepped GRE sequences resulted in local temperature elevations at DBS electrodes of no more than 0.46°C. Although no extrapolation should be made to human exams and much further study will be needed, these preliminary data are encouraging for the future use 3.0T MRI in patients with DBS. PMID:23228310

Long-term follow-up of sacral neuromodulation for lower urinary tract dysfunction.

PubMed

Peeters, Karlien; Sahai, Arun; De Ridder, Dirk; Van Der Aa, Frank

2014-05-01

To report our long-term experience of sacral neuromodulation (SNM) for various lower urinary tract dysfunctions but with a focus on efficacy, safety, re-interventions and degree of success. This is a single tertiary referral centre study that included 217 patients (86% female) who received an implantable pulse generator (IPG) (Interstim™, Medtronic, Minneapolis, USA) between 1996 and 2010. Success was considered if the initial ≥50% improvement in any of primary voiding diary variables persisted compared with baseline, but was further stratified. The mean duration of follow-up was 46.88 months. Success and cure rates were ≈70% and 20% for urgency incontinence, 68% and 33% for urgency frequency syndrome and 73% and 58% for idiopathic retention. In those patients with an unsuccessful therapy outcome, the mean time to failure was 24.6 months after implantation. There were 88 (41%) patients who had at least one device or treatment related surgical re-intervention. The re-intervention rate was 1.7 per patient with most of them (47%) occurring ≤2 years of follow-up. SNM appears effective in the long-term with a success rate after definitive IPG implant of ≈70% and complete cure rates ranging between 20% and 58% depending on indication. Patients with idiopathic retention appear to do best. The re-intervention rate is high with most occurring ≤2 years of implantation. It is likely that with the newer techniques used, efficacy and re-intervention rates will improve. © 2013 The Authors. BJU International © 2013 BJU International.

Effects of pH, lactate, hematocrit and potassium level on the accuracy of continuous glucose monitoring (CGM) in pediatric intensive care unit.

PubMed

Marics, Gábor; Koncz, Levente; Eitler, Katalin; Vatai, Barbara; Szénási, Boglárka; Zakariás, David; Mikos, Borbála; Körner, Anna; Tóth-Heyn, Péter

2015-03-19

Continuous glucose monitoring (CGM) originally was developed for diabetic patients and it may be a useful tool for monitoring glucose changes in pediatric intensive care unit (PICU). Its use is, however, limited by the lack of sufficient data on its reliability at insufficient peripheral perfusion. We aimed to correlate the accuracy of CGM with laboratory markers relevant to disturbed tissue perfusion. In 38 pediatric patients (age range, 0-18 years) requiring intensive care we tested the effect of pH, lactate, hematocrit and serum potassium on the difference between CGM and meter glucose measurements. Guardian® (Medtronic®) CGM results were compared to GEM 3000 (Instrumentation laboratory®) and point-of-care measurements. The clinical accuracy of CGM was evaluated by Clarke Error Grid -, Bland-Altman analysis and Pearson's correlation. We used Friedman test for statistical analysis (statistical significance was established as a p < 0.05). CGM values exhibited a considerable variability without any correlation with the examined laboratory parameters. Clarke, Bland-Altman analysis and Pearson's correlation coefficient demonstrated a good clinical accuracy of CGM (zone A and B = 96%; the mean difference between reference and CGM glucose was 1,3 mg/dL, 48 from the 780 calibration pairs overrunning the 2 standard deviation; Pearson's correlation coefficient: 0.83). The accuracy of CGM measurements is independent of laboratory parameters relevant to tissue hypoperfusion. CGM may prove a reliable tool for continuous monitoring of glucose changes in PICUs, not much influenced by tissue perfusion, but still not appropriate for being the base for clinical decisions.

Evaluation of Industrial Compensation to Cardiologists in 2015.

PubMed

Khan, Muhammad Shahzeb; Siddiqi, Tariq Jamal; Fatima, Kaneez; Riaz, Haris; Khosa, Faisal; Manning, Warren J; Krasuski, Richard

2017-12-15

The categorization and characterization of pharmaceutical and device manufacturers or group purchasing organization payments to clinicians is an important step toward assessing conflicts of interest and the potential impact of these payments on practice patterns. Payments have not previously been compared among the subspecialties of cardiology. This is a retrospective analysis of the Open Payments database, including all installments and payments made to doctors in the calendar year 2015 by pharmaceutical and device manufacturers or group purchasing organization. Total payments to individual physicians were then aggregated based on specialty, geographic region, and payment type. The Gini Index was further employed to calculate within each specialty to measure income disparity. In 2015, a total of $166,089,335 was paid in 943,744 payments (average $175.00 per payment) to cardiologists, including 23,372 general cardiologists, 7,530 interventional cardiologists, and 2,293 cardiac electro-physiologists. Payments were mal-distributed across the 3 subspecialties of cardiology (p <0.01), with general cardiology receiving the largest number (73.5%) and total payments (62.6%) and cardiac electrophysiologists receiving significantly higher median payments ($1,662 vs $361 for all cardiologists; p <0.01). The Medtronic Company was the largest single payer for all 3 subspecialties. In conclusion, pharmaceutical and device manufacturers or group purchasing organizations continue to make substantial payments to cardiac practitioners with a significant variation in payments made to different cardiology subspecialists. The largest number and total payments are to general cardiologists, whereas the highest median payments are made to cardiac electrophysiologists. The impact of these payments on practice patterns remains to be examined. Copyright © 2017 Elsevier Inc. All rights reserved.

Deep Brain Stimulation of the Dentato-Rubro-Thalamic Tract: Outcomes of Direct Targeting for Tremor.

PubMed

Fenoy, Albert J; Schiess, Mya C

2017-07-01

Targeting the dentato-rubro-thalamic tract (DRTt) has been suggested to be efficacious in deep brain stimulation (DBS) for tremor suppression, both in case reports and post-hoc analyses. This prospective observational study sought to analyze outcomes after directly targeting the DRTt in tremor patients. 20 consecutively enrolled intention tremor patients obtained pre-operative MRI with diffusion tensor (dTi) sequences. Mean baseline tremor amplitude based on The Essential Tremor Rating Assessment Scale was recorded. The DRTt was drawn for each individual on StealthViz software (Medtronic) using the dentate nucleus as the seed region and the ipsilateral pre-central gyrus as the end region and then directly targeted during surgery. Intraoperative testing confirmed successful tremor control. Post-operative analysis of electrode position relative to the DRTt was performed, as was post-operative assessment of tremor improvement. The mean age of patients was 66.8 years; mean duration of tremor was 16 years. Mean voltage for the L electrode = 3.4 V; R = 2.6 V. Mean distance from the center of the active electrode contact to the DRTt was 0.9 mm on the L, and 0.8 mm on the R. Improvement in arm tremor amplitude from baseline after DBS was significant (P < 0.001). Direct targeting of the DRTt in DBS is an effective strategy for tremor suppression. Accounting for hardware, software, and model limitations, depiction of the DRTt allows for placement of electrode contacts directly within the fiber tract for modulation despite any anatomical variation, which reproducibly resulted in good tremor control. © 2017 International Neuromodulation Society.

A cluster randomised trial, cost-effectiveness analysis and psychosocial evaluation of insulin pump therapy compared with multiple injections during flexible intensive insulin therapy for type 1 diabetes: the REPOSE Trial.

PubMed

Heller, Simon; White, David; Lee, Ellen; Lawton, Julia; Pollard, Daniel; Waugh, Norman; Amiel, Stephanie; Barnard, Katharine; Beckwith, Anita; Brennan, Alan; Campbell, Michael; Cooper, Cindy; Dimairo, Munyaradzi; Dixon, Simon; Elliott, Jackie; Evans, Mark; Green, Fiona; Hackney, Gemma; Hammond, Peter; Hallowell, Nina; Jaap, Alan; Kennon, Brian; Kirkham, Jackie; Lindsay, Robert; Mansell, Peter; Papaioannou, Diana; Rankin, David; Royle, Pamela; Smithson, W Henry; Taylor, Carolin

2017-04-01

Insulin is generally administered to people with type 1 diabetes mellitus (T1DM) using multiple daily injections (MDIs), but can also be delivered using infusion pumps. In the UK, pumps are recommended for patients with the greatest need and adult use is less than in comparable countries. Previous trials have been small, of short duration and have failed to control for training in insulin adjustment. To assess the clinical effectiveness and cost-effectiveness of pump therapy compared with MDI for adults with T1DM, with both groups receiving equivalent structured training in flexible insulin therapy. Pragmatic, multicentre, open-label, parallel-group cluster randomised controlled trial, including economic and psychosocial evaluations. After participants were assigned a group training course, courses were randomly allocated in pairs to either pump or MDI. Eight secondary care diabetes centres in the UK. Adults with T1DM for > 12 months, willing to undertake intensive insulin therapy, with no preference for pump or MDI, or a clinical indication for pumps. Pump or MDI structured training in flexible insulin therapy, followed up for 2 years. MDI participants used insulin analogues. Pump participants used a Medtronic Paradigm ® Veo TM (Medtronic, Watford, UK) with insulin aspart (NovoRapid, Novo Nordisk, Gatwick, UK). Primary outcome - change in glycated haemoglobin (HbA 1c ) at 2 years in participants whose baseline HbA 1c was ≥ 7.5% (58 mmol/mol). Key secondary outcome - proportion of participants with HbA 1c ≤ 7.5% at 2 years. Other outcomes at 6, 12 and 24 months - moderate and severe hypoglycaemia; insulin dose; body weight; proteinuria; diabetic ketoacidosis; quality of life (QoL); fear of hypoglycaemia; treatment satisfaction; emotional well-being; qualitative interviews with participants and staff (2 weeks), and participants (6 months); and ICERs in trial and modelled estimates of cost-effectiveness. We randomised 46 courses comprising 317 participants: 267 attended a Dose Adjustment For Normal Eating course (132 pump; 135 MDI); 260 were included in the intention-to-treat analysis, of which 235 (119 pump; 116 MDI) had baseline HbA 1c of ≥ 7.5%. HbA 1c and severe hypoglycaemia improved in both groups. The drop in HbA 1c % at 2 years was 0.85 on pump and 0.42 on MDI. The mean difference (MD) in HbA 1c change at 2 years, at which the baseline HbA 1c was ≥ 7.5%, was -0.24% [95% confidence interval (CI) -0.53% to 0.05%] in favour of the pump ( p  = 0.098). The per-protocol analysis showed a MD in change of -0.36% (95% CI -0.64% to -0.07%) favouring pumps ( p  = 0.015). Pumps were not cost-effective in the base case and all of the sensitivity analyses. The pump group had greater improvement in diabetes-specific QoL diet restrictions, daily hassle plus treatment satisfaction, statistically significant at 12 and 24 months and supported by qualitative interviews. Blinding of pump therapy was not possible, although an objective primary outcome was used. Adding pump therapy to structured training in flexible insulin therapy did not significantly enhance glycaemic control or psychosocial outcomes in adults with T1DM. To understand why few patients achieve a HbA 1c of < 7.5%, particularly as glycaemic control is worse in the UK than in other European countries. Current Controlled Trials ISRCTN61215213. This project was funded by the National Institute for Health Research (NIHR) Health Technology Assessment programme and will be published in full in Health Technology Assessment ; Vol. 21, No. 20. See the NIHR Journals Library website for further project information.

A simplified clinical prediction rule for prognosticating independent walking after spinal cord injury: a prospective study from a Canadian multicenter spinal cord injury registry.

PubMed

Hicks, Katharine E; Zhao, Yichen; Fallah, Nader; Rivers, Carly S; Noonan, Vanessa K; Plashkes, Tova; Wai, Eugene K; Roffey, Darren M; Tsai, Eve C; Paquet, Jerome; Attabib, Najmedden; Marion, Travis; Ahn, Henry; Phan, Philippe

2017-10-01

Traumatic spinal cord injury (SCI) is a debilitating condition with limited treatment options for neurologic or functional recovery. The ability to predict the prognosis of walking post injury with emerging prediction models could aid in rehabilitation strategies and reintegration into the community. To revalidate an existing clinical prediction model for independent ambulation (van Middendorp et al., 2011) using acute and long-term post-injury follow-up data, and to investigatethe accuracy of a simplified model using prospectively collected data from a Canadian multicenter SCI database, the Rick Hansen Spinal Cord Injury Registry (RHSCIR). Prospective cohort study. The analysis cohort consisted of 278 adult individuals with traumatic SCI enrolled in the RHSCIR for whom complete neurologic examination data and Functional Independence Measure (FIM) outcome data were available. The FIM locomotor score was used to assess independent walking ability (defined as modified or complete independence in walk or combined walk and wheelchair modality) at 1-year follow-up for each participant. A logistic regression (LR) model based on age and four neurologic variables was applied to our cohort of 278 RHSCIR participants. Additionally, a simplified LR model was created. The Hosmer-Lemeshow goodness of fit test was used to check if the predictive model is applicable to our data set. The performance of the model was verified by calculating the area under the receiver operating characteristic curve (AUC). The accuracy of the model was tested using a cross-validation technique. This study was supported by a grant from The Ottawa Hospital Academic Medical Organization ($50,000 over 2 years). The RHSCIR is sponsored by the Rick Hansen Institute and is supported by funding from Health Canada, Western Economic Diversification Canada, and the provincial governments of Alberta, British Columbia, Manitoba, and Ontario. ET and JP report receiving grants from the Rick Hansen Institute (approximately $60,000 and $30,000 per year, respectively). DMR reports receiving remuneration for consulting services provided to Palladian Health, LLC and Pacira Pharmaceuticals, Inc ($20,000-$30,000 annually), although neither relationship presents a potential conflict of interest with the submitted work. KEH received a grant for involvement in the present study from the Government of Canada as part of the Canada Summer Jobs Program ($3,000). JP reports receiving an educational grant from Medtronic Canada outside of the submitted work ($75,000 annually). TM reports receiving educational fellowship support from AO Spine, AO Trauma, and Medtronic; however, none of these relationships are financial in nature. All remaining authors have no conflicts of interest to disclose. The fitted prediction model generated 85% overall classification accuracy, 79% sensitivity, and 90% specificity. The prediction model was able to accurately classify independent walking ability (AUC 0.889, 95% confidence interval [CI] 0.846-0.933, p<.001) compared with the existing prediction model, despite the use of a different outcome measure (FIM vs. Spinal Cord Independence Measure) to qualify walking ability. A simplified, three-variable LR model based on age and two neurologic variables had an overall classification accuracy of 84%, with 76% sensitivity and 90% specificity, demonstrating comparable accuracy with its five-variable prediction model counterpart. The AUC was 0.866 (95% CI 0.816-0.916, p<.01), only marginally less than that of the existing prediction model. A simplified predictive model with similar accuracy to a more complex model for predicting independent walking was created, which improves utility in a clinical setting. Such models will allow clinicians to better predict the prognosis of ambulation in individuals who have sustained a traumatic SCI. Copyright © 2017 The Authors. Published by Elsevier Inc. All rights reserved.

Chronic multisite brain recordings from a totally implantable bidirectional neural interface: experience in 5 patients with Parkinson's disease.

PubMed

Swann, Nicole C; de Hemptinne, Coralie; Miocinovic, Svjetlana; Qasim, Salman; Ostrem, Jill L; Galifianakis, Nicholas B; Luciano, Marta San; Wang, Sarah S; Ziman, Nathan; Taylor, Robin; Starr, Philip A

2018-02-01

OBJECTIVE Dysfunction of distributed neural networks underlies many brain disorders. The development of neuromodulation therapies depends on a better understanding of these networks. Invasive human brain recordings have a favorable temporal and spatial resolution for the analysis of network phenomena but have generally been limited to acute intraoperative recording or short-term recording through temporarily externalized leads. Here, the authors describe their initial experience with an investigational, first-generation, totally implantable, bidirectional neural interface that allows both continuous therapeutic stimulation and recording of field potentials at multiple sites in a neural network. METHODS Under a physician-sponsored US Food and Drug Administration investigational device exemption, 5 patients with Parkinson's disease were implanted with the Activa PC+S system (Medtronic Inc.). The device was attached to a quadripolar lead placed in the subdural space over motor cortex, for electrocorticography potential recordings, and to a quadripolar lead in the subthalamic nucleus (STN), for both therapeutic stimulation and recording of local field potentials. Recordings from the brain of each patient were performed at multiple time points over a 1-year period. RESULTS There were no serious surgical complications or interruptions in deep brain stimulation therapy. Signals in both the cortex and the STN were relatively stable over time, despite a gradual increase in electrode impedance. Canonical movement-related changes in specific frequency bands in the motor cortex were identified in most but not all recordings. CONCLUSIONS The acquisition of chronic multisite field potentials in humans is feasible. The device performance characteristics described here may inform the design of the next generation of totally implantable neural interfaces. This research tool provides a platform for translating discoveries in brain network dynamics to improved neurostimulation paradigms. Clinical trial registration no.: NCT01934296 (clinicaltrials.gov).

Beta oscillations in freely moving Parkinson's subjects are attenuated during deep brain stimulation.

PubMed

Quinn, Emma J; Blumenfeld, Zack; Velisar, Anca; Koop, Mandy Miller; Shreve, Lauren A; Trager, Megan H; Hill, Bruce C; Kilbane, Camilla; Henderson, Jaimie M; Brontë-Stewart, Helen

2015-11-01

Investigations into the effect of deep brain stimulation (DBS) on subthalamic (STN) beta (13-30 Hz) oscillations have been performed in the perioperative period with the subject tethered to equipment. Using an embedded sensing neurostimulator, this study investigated whether beta power was similar in different resting postures and during forward walking in freely moving subjects with Parkinson's disease (PD) and whether STN DBS attenuated beta power in a voltage-dependent manner. Subthalamic local field potentials were recorded from the DBS lead, using a sensing neurostimulator (Activa(®) PC+S, Medtronic, Inc., Food and Drug Administration- Investigational Device Exemption (IDE)-, institutional review board-approved) from 15 PD subjects (30 STNs) off medication during lying, sitting, and standing, during forward walking, and during randomized periods of 140 Hz DBS at 0 V, 1 V, and 2.5/3 V. Continuous video, limb angular velocity, and forearm electromyography recordings were synchronized with neural recordings. Data were parsed to avoid any movement or electrical artifact during resting states. Beta power was similar during lying, sitting, and standing (P = 0.077, n = 28) and during forward walking compared with the averaged resting state (P = 0.466, n = 24), although akinetic rigid PD subjects tended to exhibit decreased beta power when walking. Deep brain stimulation at 3 V and at 1 V attenuated beta power compared with 0 V (P < 0.003, n = 14), and this was voltage dependent (P < 0.001). Beta power was conserved during resting and forward walking states and was attenuated in a voltage-dependent manner during 140-Hz DBS. Phenotype may be an important consideration if this is used for closed-loop DBS. © 2015 International Parkinson and Movement Disorder Society.

Evaluating the automated blood glucose pattern detection and case-retrieval modules of the 4 Diabetes Support System.

PubMed

Schwartz, Frank L; Vernier, Stanley J; Shubrook, Jay H; Marling, Cynthia R

2010-11-01

We have developed a prototypical case-based reasoning system to enhance management of patients with type 1 diabetes mellitus (T1DM). The system is capable of automatically analyzing large volumes of life events, self-monitoring of blood glucose readings, continuous glucose monitoring system results, and insulin pump data to detect clinical problems. In a preliminary study, manual entry of large volumes of life-event and other data was too burdensome for patients. In this study, life-event and pump data collection were automated, and then the system was reevaluated. Twenty-three adult T1DM patients on insulin pumps completed the five-week study. A usual daily schedule was entered into the database, and patients were only required to upload their insulin pump data to Medtronic's CareLink® Web site weekly. Situation assessment routines were run weekly for each participant to detect possible problems, and once the trial was completed, the case-retrieval module was tested. Using the situation assessment routines previously developed, the system found 295 possible problems. The enhanced system detected only 2.6 problems per patient per week compared to 4.9 problems per patient per week in the preliminary study (p=.017). Problems detected by the system were correctly identified in 97.9% of the cases, and 96.1% of these were clinically useful. With less life-event data, the system is unable to detect certain clinical problems and detects fewer problems overall. Additional work is needed to provide device/software interfaces that allow patients to provide this data quickly and conveniently. © 2010 Diabetes Technology Society.

Microembolism and catheter ablation I: a comparison of irrigated radiofrequency and multielectrode-phased radiofrequency catheter ablation of pulmonary vein ostia.

PubMed

Haines, David E; Stewart, Mark T; Dahlberg, Sarah; Barka, Noah D; Condie, Cathy; Fiedler, Gary R; Kirchhof, Nicole A; Halimi, Franck; Deneke, Thomas

2013-02-01

Cerebral diffusion-weighted MRI lesions have been observed after catheter ablation of atrial fibrillation. We hypothesized that conditions predisposing to microembolization could be identified using a porcine model of pulmonary vein ablation and an extracorporeal circulation loop. Ablations of the pulmonary veins were performed in 18 swine with echo monitoring. The femoral artery and vein were cannulated and an extracorporeal circulation loop with 2 ultrasonic bubble detectors and a 73-μm filter were placed in series. Microemboli and microbubbles were compared between ablation with an irrigated radiofrequency system (Biosense-Webster) and a phased radiofrequency multielectrode system (pulmonary vein ablation catheter [PVAC], Medtronic, Inc, Carlsbad, CA) in unipolar and 3 blended unipolar/bipolar modes. Animal pathology was examined. The size and number of microbubbles observed during ablation ranged from 30 to 180 μm and 0 to 3253 bubbles per ablation. Microbubble volumes with PVAC (29.1 nL) were greater than with irrigated radiofrequency (0.4 nL; P=0.045), and greatest with type II or III microbubbles on transesophageal echocardiography. Ablation with the PVAC showed fewest microbubbles in the unipolar mode (P=0.012 versus bipolar). The most occurred during bipolar energy delivery with overlap of proximal and distal electrodes (median microbubble volume, 1744 nL; interquartile range, 737-4082 nL; maximum, 19 516 nL). No cerebral MRI lesions were seen, but 2 animals had renal embolization. Left atrial ablation with irrigated radiofrequency and PVAC catheters in swine is associated with microbubble and microembolus production. Avoiding overlap of electrodes 1 and 10 on PVAC should reduce the microembolic burden associated with this procedure.

Continuous glucose monitoring detected hypoglycaemia in the Treating to Target in Type 2 Diabetes Trial (4-T).

PubMed

Levy, J C; Davies, M J; Holman, R R

2017-09-01

Hypoglycaemia is a significant risk in insulin treated type 2 diabetes and has been associated with future risk of cardiovascular events. We compared the frequency of low-glucose events using continuous glucose monitoring (CGM) with that of self-reported hypoglycemic events at the end of the first and third years of the Treating to Target in Type 2 Diabetes Trial (4-T), which compared biphasic, prandial and basal insulin regimens added to sulfonylurea and metformin. CGM using a Medtronic Gold system was performed in a subgroup of 4-T participants. CGM detected low-glucose events were defined at thresholds of ≤3.0 (CGM3.0) and ≤2.2 (CGM2.2) mmol/l. Of the 110 participants, 106 and 70 had CGM analysable data at the end of years 1 and 3 respectively. In both years, the frequency of CGM detected low glucose events was several fold higher than that of self-reported hypoglycaemia (symptoms with blood glucose less than 3.1mmol/l [<56mg/dl]). At the end of the first year, CGM3.0 and CGM2.2 mean (95%CI) event frequencies, expressed at events per participant per year, were 120 (85, 155) and 41 (21, 61) compared with 17 (8, 29) self-reported events during CGM, each p=0.001. The disparity at the end of the third year was similar. These data demonstrate the likely under-reporting of hypoglycaemia and of potential hypoglycaemia unawareness in clinical trials. The clinical implications of these findings need to be explored further (ISRCTN No ISRCTN51125379). Copyright © 2017. Published by Elsevier B.V.

Interstitial fluid glucose dynamics during insulin-induced hypoglycaemia.

PubMed

Steil, G M; Rebrin, K; Hariri, F; Jinagonda, S; Tadros, S; Darwin, C; Saad, M F

2005-09-01

Glucose sensors often measure s.c. interstitial fluid (ISF) glucose rather than blood or plasma glucose. Putative differences between plasma and ISF glucose include a protracted delay during the recovery from hypoglycaemia and an increased gradient during hyperinsulinaemia. These have often been investigated using sensor systems that have delays due to signal smoothing, or require long equilibration times. The aim of the present study was to define these relationships during hypoglycaemia in a well-equilibrated system with no smoothing. Hypoglycaemia was induced by i.v. insulin infusion (360 pmol.m(-2).min(-1)) in ten non-diabetic subjects. Glucose was sequentially clamped at approximately 5, 4.2 and 3.1 mmol/l and allowed to return to normoglycaemia. Subjects wore two s.c. glucose sensors (Medtronic MiniMed, Northridge, CA, USA) that had been inserted for more than 12 h. A two-compartment model was used to quantify the delay and gradient. The delay during the fall in plasma glucose was not different from the delay during recovery (8.3+/-0.67 vs 6.3+/-1.1 min; p=0.27) and no differences were observed in the ratio of sensor current to plasma glucose at basal insulin (2.7+/-0.25 nA.mmol(-1).l) compared with any of the hyperinsulinaemic clamp phases (2.8+/-0.18, 2.7+/-0.021, 2.9+/-0.21; p=NS). The ratio was significantly elevated following recovery to normoglycaemia (3.1+/-0.2 nA.mmol(-1).l; p<0.001). The elevated ratio suggests that the plasma to ISF glucose gradient was decreased following hypoglycaemia, possibly due to increased skin blood flow. Recovery from hypoglycaemia is not accompanied by a protracted delay and insulin does not increase the plasma to s.c. ISF glucose gradient.

Continuous glucose monitoring on the ICU using a subcutaneous sensor.

PubMed

Punke, M A; Decker, C; Wodack, K; Reuter, D A; Kluge, S

2015-06-01

Hypoglycemia is a frequent and feared complication of insulin therapy on the intensive care unit (ICU). Sedated patients in particular are at risk for hypoglycemia due to the absence of clinical symptoms. Furthermore, recent studies point to a correlation between the variability of blood glucose and mortality. Therefore, continuous glucose monitoring has the potential to influence outcome due to a better control of blood glucose in critically ill patients. We evaluated the efficacy, accuracy and safety of a new commercially available subcutaneous continuous glucose monitoring system (sCGM; Sentrino®, Medtronic) in a pilot study in critically ill adult patients. sCGM data were recorded for up to 72 h and values were compared with blood glucose values measured by cassette-based blood gas analyzer (BGA). A total of 14 patients (eight male, six female), with a mean age of 62.1 ± 9.8 years, referred to the ICU after major abdominal surgery were studied. The average simplified acute physiology score (SAPS II) was 35 ± 9. Three patients had known type II diabetes. The average runtime of sensors was 44.1 ± 22.1 h. In comparison to BGA, measurement of blood glucose by sCGM revealed an accuracy of 1.5 mg/dl, and a precision of +34.2 mg/dl to -31.2 mg/dl. Linn's concordance correlation coefficient yielded 0.74 with a 95% confidence interval of 0.68-0.78. No hypoglycemic events, defined as a blood glucose level below 70 mg/dl, occurred during treatment. sCGM monitoring via a subcutaneous sensor demonstrated high accuracy and considerable variability compared to blood gas samples, even in critically ill patients.

Analysis of glucose responses to automated insulin suspension with sensor-augmented pump therapy.

PubMed

Ly, Trang T; Nicholas, Jennifer A; Retterath, Adam; Davis, Elizabeth A; Jones, Timothy W

2012-07-01

The advent of sensor-augmented pump therapy with a low-glucose suspend (LGS) function (Medtronic Paradigm Veo System), allowing insulin to be automatically suspended for up to 2 h when sensor glucose falls below a preset threshold, has the potential to reduce the duration of hypoglycemia. In this article, we analyzed blood glucose profiles following a full 2-h insulin suspension activated by the LGS function, as well as examined different patterns of use among patients. Data from a cohort of participants using the Veo System for up to 6 months were analyzed to determine the time and duration of insulin suspension activated by the LGS function. We further evaluated overnight suspend events with no patient response occurring prior to 3:00 a.m., which allowed us to determine the pattern of sensor glucose values with no patient intervention during and after the period of insulin suspension. There were 3,128 LGS events during the 2,493 days evaluated. The median duration was 11.2 min, and 36% of events occurred overnight. There were 126 full 2-h suspend events that occurred overnight with no patient response, occurring before 3:00 a.m. For these events, the mean sensor glucose at the end of the 2-h suspend period was 99 ± 6 mg/dL ([means ± SE] 5.5 ± 0.3 mmol/L). The mean sensor glucose 2 h after insulin delivery resumed was 155 ± 10 mg/dL (8.6 ± 0.6 mmol/L). There were no episodes of severe hypoglycemia or diabetic ketoacidosis. Analyses of sensor glucose patterns following insulin suspension activated by LGS suggest that this technology is safe and unlikely to be associated with adverse outcomes.

Outpatient safety assessment of an in-home predictive low-glucose suspend system with type 1 diabetes subjects at elevated risk of nocturnal hypoglycemia.

PubMed

Buckingham, Bruce A; Cameron, Fraser; Calhoun, Peter; Maahs, David M; Wilson, Darrell M; Chase, H Peter; Bequette, B Wayne; Lum, John; Sibayan, Judy; Beck, Roy W; Kollman, Craig

2013-08-01

Nocturnal hypoglycemia is a common problem with type 1 diabetes. In the home setting, we conducted a pilot study to evaluate the safety of a system consisting of an insulin pump and continuous glucose monitor communicating wirelessly with a bedside computer running an algorithm that temporarily suspends insulin delivery when hypoglycemia is predicted. After the run-in phase, a 21-night randomized trial was conducted in which each night was randomly assigned 2:1 to have either the predictive low-glucose suspend (PLGS) system active (intervention night) or inactive (control night). Three predictive algorithm versions were studied sequentially during the study for a total of 252 intervention and 123 control nights. The trial included 19 participants 18-56 years old with type 1 diabetes (hemoglobin A1c level of 6.0-7.7%) who were current users of the MiniMed Paradigm® REAL-Time Revel™ System and Sof-sensor® glucose sensor (Medtronic Diabetes, Northridge, CA). With the final algorithm, pump suspension occurred on 53% of 77 intervention nights. Mean morning glucose level was 144±48 mg/dL on the 77 intervention nights versus 133±57 mg/dL on the 37 control nights, with morning blood ketones >0.6 mmol/L following one intervention night. Overnight hypoglycemia was lower on intervention than control nights, with at least one value ≤70 mg/dL occurring on 16% versus 30% of nights, respectively, with the final algorithm. This study demonstrated that the PLGS system in the home setting is safe and feasible. The preliminary efficacy data appear promising with the final algorithm reducing nocturnal hypoglycemia by almost 50%.

Dual chamber arrhythmia detection in the implantable cardioverter defibrillator.

PubMed

Dijkman, B; Wellens, H J

2000-10-01

Dual chamber implantable cardioverter defibrillator (ICD) technology extended ICD therapy to more than termination of hemodynamically unstable ventricular tachyarrhythmias. It created the basis for dual chamber arrhythmia management in which dependable detection is important for treatment and prevention of both ventricular and atrial arrhythmias. Dual chamber detection algorithms were investigated in two Medtronic dual chamber ICDs: the 7250 Jewel AF (33 patients) and the 7271 Gem DR (31 patients). Both ICDs use the same PR Logic algorithm to interpret tachycardia as ventricular tachycardia (VT), supraventricular tachycardia (SVT), or dual (VT+ SVT). The accuracy of dual chamber detection was studied in 310 of 1,367 spontaneously occurring tachycardias in which rate criterion only was not sufficient for arrhythmia diagnosis. In 78 episodes there was a double tachycardia, in 223 episodes SVT was detected in the VT or ventricular fibrillation zone, and in 9 episodes arrhythmia was detected outside the boundaries of the PR Logic functioning. In 100% of double tachycardias the VT was correctly diagnosed and received priority treatment. SVT was seen in 59 (19%) episodes diagnosed as VT. The causes of inappropriate detection were (1) algorithm failure (inability to fulfill the PR

The economic impact of battery longevity in implantable cardioverter-defibrillators for cardiac resynchronization therapy: the hospital and healthcare system perspectives.

PubMed

Landolina, Maurizio; Morani, Giovanni; Curnis, Antonio; Vado, Antonello; D'Onofrio, Antonio; Bianchi, Valter; Stabile, Giuseppe; Crosato, Martino; Petracci, Barbara; Ceriotti, Carlo; Bontempi, Luca; Morosato, Martina; Ballari, Gian Paolo; Gasparini, Maurizio

2017-08-01

Patients receiving cardiac resynchronization therapy defibrillators (CRT-Ds) are likely to undergo one or more device replacements, mainly for battery depletion. We assessed the economic impact of battery depletion on the overall cost of CRT-D treatment from the perspectives of the healthcare system and the hospital. We also compared devices of different generations and from different manufacturers in terms of therapy cost. We analysed data on 1792 CRT-Ds implanted in 1399 patients in 9 Italian centres. We calculated the replacement probability and the total therapy cost over 6 years, stratified by device generation and manufacturer. Public tariffs from diagnosis-related groups were used together with device prices and hospitalization costs. Generators were from 3 manufacturers: Boston Scientific (667, 37%), Medtronic (973, 54%), and St Jude Medical (152, 9%). The replacement probability at 6 years was 83 and 68% for earlier- and recent-generation devices, respectively. The need for replacement increased total therapy costs by more than 50% over the initial implantation cost for hospitals and by more than 30% for healthcare system. The improved longevity of recent-generation CRT-Ds reduced the therapy cost by ∼6% in both perspectives. Among recent-generation CRT-Ds, the replacement probability of devices from different manufacturers ranged from 12 to 70%. Consequently, the maximum difference in therapy cost between manufacturers was 40% for hospitals and 19% for the healthcare system. Differences in CRT-D longevity strongly affect the overall therapy cost. While the use of recent-generation devices has reduced the cost, significant differences exist among currently available systems. © The Author 2016. Published by Oxford University Press on behalf of the European Society of Cardiology.

Implantable cardioverter-defibrillator lead failure in children and young adults: a matter of lead diameter or lead design?

PubMed

Janson, Christopher M; Patel, Akash R; Bonney, William J; Smoots, Karen; Shah, Maully J

2014-01-21

This study aimed to investigate the impact of lead diameter and design on implantable cardioverter-defibrillator (ICD) lead survival in children and young adults. Recent reports have called attention to high rates of lead failure in adults with small-diameter ICD leads, but data in the pediatric population is limited. We reviewed lead performance in consecutive subjects ≤30 years with transvenous right ventricular ICD leads implanted at our center between January 1995 and October 2011. Lead failure was defined as fracture, perforation, or sensing failure necessitating revision. A total of 120 ICD leads were implanted in 101 patients at a mean age of 15.5 ± 4.9 years. There were 47 small-diameter (≤8-F) and 73 standard-diameter (>8-F) leads. During a median follow-up of 28.7 months (interquartile range: 14.4 to 59.2 months), there were 25 lead failures (21% prevalence), with an incidence of 5.6%/year (95% confidence interval: 3.4 to 7.8). Sprint Fidelis (SF) (Medtronic, Inc., Minneapolis, Minnesota) leads had lower 3-year (69% vs. 92%, p < 0.01) and 5-year (44% vs. 86%, p < 0.01) survival probabilities than standard-diameter leads. In multivariate Cox regression, SF design conferred the greatest hazard ratio for lead failure (hazard ratio: 4.42, 95% confidence interval: 1.73 to 11.29, p < 0.01). Age and linear growth were not significantly associated with lead failure. In this single-center pediatric study that evaluated lead diameter, lead design, and patient factors, the SF design conferred the highest risk of lead failure, suggesting that design rather than diameter is the critical issue in ICD lead performance. Copyright © 2014 American College of Cardiology Foundation. Published by Elsevier Inc. All rights reserved.

Optimal insulin pump dosing and postprandial glycemia following a pizza meal using the continuous glucose monitoring system.

PubMed

Jones, Susan M; Quarry, Jill L; Caldwell-McMillan, Molly; Mauger, David T; Gabbay, Robert A

2005-04-01

We attempted to identify an optimal insulin pump meal bolus by comparing postprandial sensor glucose values following three methods of insulin pump meal bolusing for a consistent pizza meal. Twenty-four patients with type 1 diabetes participated in a study to compare postprandial glucose values following three meal bolus regimens for a consistent evening pizza meal. Each participant utilized the following insulin lispro regimens on consecutive evenings, and glucose values were tracked by the Continuous Glucose Monitoring System (CGMS, Medtronic MiniMed, Northridge, CA): (a) single-wave bolus (100% of insulin given immediately); (b) 4-h dual-wave bolus (50% of insulin given immediately and 50% given over a 4-h period); and (c) 8-h dual-wave bolus (50% of insulin given immediately and 50% given over a 8-h period). Total insulin bolus amount was kept constant for each pizza meal. Divergence in blood glucose among the regimens was greatest at 8-12 h. The 8-h dual-wave bolus provided the best glycemic control and lowest mean glucose values (singlewave bolus, 133 mg/dL; 4-h dual-wave bolus, 145 mg/dL; 8-h dual-wave bolus, 104 mg/dL), leading to a difference in mean glucose of 29 mg/dL for the single-wave bolus versus the 8-h dual-wave bolus and 42 mg/dL for the 4-h dual-wave bolus versus the 8-h dual-wave bolus. The lower mean glucose in the 8-h dual-wave bolus was not associated with any increased incidence of hypoglycemia. Use of a dual-wave bolus extended over an 8-h period following a pizza meal provided significantly less postprandial hyperglycemia in the late postprandial period (8-12 h) with no increased risk of hypoglycemia.

Differential effects of subcutaneous electrical stimulation (SQS) and transcutaneous electrical nerve stimulation (TENS) in rodent models of chronic neuropathic or inflammatory pain.

PubMed

Vera-Portocarrero, Louis P; Cordero, Toni; Billstrom, Tina; Swearingen, Kim; Wacnik, Paul W; Johanek, Lisa M

2013-01-01

Electrical stimulation has been used for many years for the treatment of pain. Present-day research demonstrates that stimulation targets and parameters impact the induction of specific pain-modulating mechanisms. New targets are increasingly being investigated clinically, but the scientific rationale for a particular target is often not well established. This present study compares the behavioral effects of targeting peripheral axons by electrode placement in the subcutaneous space vs. electrode placement on the surface of the skin in a rodent model. Rodent models of inflammatory and neuropathic pain were used to investigate subcutaneous electrical stimulation (SQS) vs. transcutaneous electrical nerve stimulation (TENS). Electrical parameters and relative location of the leads were held constant under each condition. SQS had cumulative antihypersensitivity effects in both inflammatory and neuropathic pain rodent models, with significant inhibition of mechanical hypersensitivity observed on days 3-4 of treatment. In contrast, reduction of thermal hyperalgesia in the inflammatory model was observed during the first four days of treatment with SQS, and reduction of cold allodynia in the neuropathic pain model was seen only on the first day with SQS. TENS was effective in the inflammation model, and in agreement with previous studies, tolerance developed to the antihypersensitivity effects of TENS. With the exception of a reversal of cold hypersensitivity on day 1 of testing, TENS did not reveal significant analgesic effects in the neuropathic pain rodent model. The results presented show that TENS and SQS have different effects that could point to unique biologic mechanisms underlying the analgesic effect of each therapy. Furthermore, this study is the first to demonstrate in an animal model that SQS attenuates neuropathic and inflammatory-induced pain behaviors. © 2013 Medtronic, Inc.

Do we need to establish guidelines for patients with neuromodulation implantable devices, including spinal cord stimulators undergoing nonspinal surgeries?

PubMed Central

Ghaly, Ramsis F.; Tverdohleb, Tatiana; Candido, Kenneth D.; Knezevic, Nebojsa Nick

2016-01-01

Background: Spinal cord stimulation is currently approved to treat chronic intractable pain of the trunk and limbs. However, such implantable electronic devices are vulnerable to external electrical currents and magnetic fields. Within the hospitals and modern operating rooms (ORs), there is an abundance of electrical devices and other types of equipment that could interfere with such devices. Despite the increasing number of patients with neuromodulation implantable devices, there are no written guidelines available or consensus of cautions for such patients undergoing unrelated surgery. Case Descriptions: A 60-year-old female with a permanent St. Jude's spinal cord stimulator (SCS) presented for open total abdominal hysterectomy. Both the anesthesia and gynecology staffs were aware of the device presence, but were unaware of any precautions regarding intraoperative management. The device was found to be nonmagnetic resonance imaging compatible, and bipolar cautery was used instead of monopolar cautery. A 59-year-old female with a 9-year-old permanent Medtronic SCS, presented for right total hip arthroplasty. The device was switched off prior to entering the OR, bipolar cautery was used, and grounding pads were placed away from her battery site. In each case, the manufacturer's representative was contacted preoperative. Both surgeries proceeded uneventfully. Conclusions: The Food and Drug Administration safety information manual warns about the use of diathermy, concomitant implanted stimulation devices, lithotripsy, external defibrillation, radiation therapy, ultrasonic scanning, and high-output ultrasound, all of which can lead to permanent implant damage if not turned off prior to undertaking procedures. Lack of uniform guidelines makes intraoperative management, as well as remote anesthesia care of patients with previously implanted SCSs unsafe. PMID:26958424

Extraction of SelectSecure leads compared to conventional pacing leads in patients with congenital heart disease and congenital atrioventricular block.

PubMed

Shepherd, Emma; Stuart, Graham; Martin, Rob; Walsh, Mark A

2015-06-01

SelectSecure™ pacing leads (Medtronic Inc) are increasingly being used in pediatric patients and adults with structural congenital heart disease. The 4Fr lead is ideal for patients who may require lifelong pacing and can be advantageous for patients with complex anatomy. The purpose of this study was to compare the extraction of SelectSecure leads with conventional (stylette-driven) pacing leads in patients with structural congenital heart disease and congenital atrioventricular block. The data on lead extractions from pediatric and adult congenital heart disease (ACHD) patients from August 2004 to July 2014 at Bristol Royal Hospital for Children and the Bristol Heart Institute were reviewed. Multivariable regression analysis was used to determine whether conventional pacing leads were associated with a more difficult extraction process. A total of 57 patients underwent pacemaker lead extractions (22 SelectSecure, 35 conventional). No deaths occurred. Mean age at the time of extraction was 17.6 ± 10.5 years, mean weight was 47 ± 18 kg, and mean lead age was 5.6 ± 2.6 years (range 1-11 years). Complex extraction (partial extraction/femoral extraction) was more common in patients with conventional pacing leads at univariate (P < .01) and multivariate (P = .04) levels. Lead age was also a significant predictor of complex extraction (P < .01). SelectSecure leads can be successfully extracted using techniques that are used for conventional pacing leads. They are less likely to be partially extracted and are less likely to require extraction using a femoral approach compared with conventional pacing leads. Copyright © 2015 Heart Rhythm Society. Published by Elsevier Inc. All rights reserved.

Reduction in unnecessary ventricular pacing fails to affect hard clinical outcomes in patients with preserved left ventricular function: a meta-analysis.

PubMed

Shurrab, Mohammed; Healey, Jeff S; Haj-Yahia, Saleem; Kaoutskaia, Anna; Boriani, Giuseppe; Carrizo, Aldo; Botto, Gianluca; Newman, David; Padeletti, Luigi; Connolly, Stuart J; Crystal, Eugene

2017-02-01

Several pacing modalities across multiple manufacturers have been introduced to minimize unnecessary right ventricular pacing. We conducted a meta-analysis to assess whether ventricular pacing reduction modalities (VPRM) influence hard clinical outcomes in comparison to standard dual-chamber pacing (DDD). An electronic search was performed using Cochrane Central Register, PubMed, Embase, and Scopus. Only randomized controlled trials (RCT) were included in this analysis. Outcomes of interest included: frequency of ventricular pacing (VP), incident persistent/permanent atrial fibrillation (PerAF), all-cause hospitalization and all-cause mortality. Odds ratios (OR) were reported for dichotomous variables. Seven RCTs involving 4119 adult patients were identified. Ventricular pacing reduction modalities were employed in 2069 patients: (MVP, Medtronic Inc.) in 1423 and (SafeR, Sorin CRM, Clamart) in 646 patients. Baseline demographics and clinical characteristics were similar between VPRM and DDD groups. The mean follow-up period was 2.5 ± 0.9 years. Ventricular pacing reduction modalities showed uniform reduction in VP in comparison to DDD groups among all individual studies. The incidence of PerAF was similar between both groups {8 vs. 10%, OR 0.84 [95% confidence interval (CI) 0.57; 1.24], P = 0.38}. Ventricular pacing reduction modalities showed no significant differences in comparison to DDD for all-cause hospitalization or all-cause mortality [9 vs. 11%, OR 0.82 (95% CI 0.65; 1.03), P= 0.09; 6 vs. 6%, OR 0.97 (95% CI 0.74; 1.28), P = 0.84, respectively]. Novel VPRM measures effectively reduce VP in comparison to standard DDD. When actively programmed, VPRM did not improve clinical outcomes and were not superior to standard DDD programming in reducing incidence of PerAF, all-cause hospitalization, or all-cause mortality.

Modeling deep brain stimulation: point source approximation versus realistic representation of the electrode

NASA Astrophysics Data System (ADS)

Zhang, Tianhe C.; Grill, Warren M.

2010-12-01

Deep brain stimulation (DBS) has emerged as an effective treatment for movement disorders; however, the fundamental mechanisms by which DBS works are not well understood. Computational models of DBS can provide insights into these fundamental mechanisms and typically require two steps: calculation of the electrical potentials generated by DBS and, subsequently, determination of the effects of the extracellular potentials on neurons. The objective of this study was to assess the validity of using a point source electrode to approximate the DBS electrode when calculating the thresholds and spatial distribution of activation of a surrounding population of model neurons in response to monopolar DBS. Extracellular potentials in a homogenous isotropic volume conductor were calculated using either a point current source or a geometrically accurate finite element model of the Medtronic DBS 3389 lead. These extracellular potentials were coupled to populations of model axons, and thresholds and spatial distributions were determined for different electrode geometries and axon orientations. Median threshold differences between DBS and point source electrodes for individual axons varied between -20.5% and 9.5% across all orientations, monopolar polarities and electrode geometries utilizing the DBS 3389 electrode. Differences in the percentage of axons activated at a given amplitude by the point source electrode and the DBS electrode were between -9.0% and 12.6% across all monopolar configurations tested. The differences in activation between the DBS and point source electrodes occurred primarily in regions close to conductor-insulator interfaces and around the insulating tip of the DBS electrode. The robustness of the point source approximation in modeling several special cases—tissue anisotropy, a long active electrode and bipolar stimulation—was also examined. Under the conditions considered, the point source was shown to be a valid approximation for predicting excitation of populations of neurons in response to DBS.

Monitoring the wild black bear's reaction to human and environmental stressors

PubMed Central

2011-01-01

Background Bears are among the most physiologically remarkable mammals. They spend half their life in an active state and the other half in a state of dormancy without food or water, and without urinating, defecating, or physical activity, yet can rouse and defend themselves when disturbed. Although important data have been obtained in both captive and wild bears, long-term physiological monitoring of bears has not been possible until the recent advancement of implantable devices. Results Insertable cardiac monitors that were developed for use in human heart patients (Reveal® XT, Medtronic, Inc) were implanted in 15 hibernating bears. Data were recovered from 8, including 2 that were legally shot by hunters. Devices recorded low heart rates (pauses of over 14 seconds) and low respiration rates (1.5 breaths/min) during hibernation, dramatic respiratory sinus arrhythmias in the fall and winter months, and elevated heart rates in summer (up to 214 beats/min (bpm)) and during interactions with hunters (exceeding 250 bpm). The devices documented the first and last day of denning, a period of quiescence in two parturient females after birthing, and extraordinary variation in the amount of activity/day, ranging from 0 (winter) to 1084 minutes (summer). Data showed a transition toward greater nocturnal activity in the fall, preceding hibernation. The data-loggers also provided evidence of the physiological and behavioral responses of bears to our den visits to retrieve the data. Conclusions Annual variations in heart rate and activity have been documented for the first time in wild black bears. This technique has broad applications to wildlife management and physiological research, enabling the impact of environmental stressors from humans, changing seasons, climate change, social interactions and predation to be directly monitored over multiple years. PMID:21849079

Benefits of three-month continuous glucose monitoring for persons with diabetes using insulin pumps and sensors.

PubMed

Peterson, Karolina; Zapletalova, Jana; Kudlova, Pavla; Matuskova, Veronika; Bartek, Josef; Novotny, Dalibor; Chlup, Rudolf

2009-03-01

The latest Paradigm 722 insulin pump, Medtronic MiniMed, USA, enables daily reading of 288 interstitial fluid glucose concentrations determined by a sensor inserted into subcutaneous tissue; the sensor signals are transmitted into the insulin pump, enabling the patient to see real-time glucose concentration on the display and adapt further treatment. To assess the evolution of HbA1c over the course of a 3-month period in two cohorts of persons with type 1 (n=39) or type 2 (n=3) diabetes (PWD): 1) PWD on Paradigm 722 using sensors for continuous glucose monitoring (CGM group), 2) PWD on other types of insulin pumps performing intensive self-monitoring as before (3 to 6 times/d) on glucometer Linus, Wellion, Agamatrix (control group). Compliant PWDs using insulin pump with insulin aspart for several previous months were included in the study. Seventeen were put on Paradigm 722 with CGM and 25 were included in the control group. Paired t-test and the statistical program SPSS v.15.0 were used to analyze the data. There was no significant difference in age between the two groups (P=0.996), in diabetes duration (P=0.482) or in daily insulin dose (P=0.469). In the CGM group (but not in the control group) HbA1c/IFCC dropped from 6.98+/-0.43 % to 5.98+/-0.36 % (P=0.006) within 1 month and remained reduced. The use of the Paradigm 722 insulin pump with CGM resulted in significant improvement in HbA1c which appeared within one month and remained throughout the whole 3-month study period. No significant improvement in HbA1c was seen in the control group.

Glucose sensor evaluation of glycemic instability in pediatric type 1 diabetes mellitus.

PubMed

Alemzadeh, Ramin; Loppnow, Cindy; Parton, Elaine; Kirby, Midge

2003-01-01

Maintaining blood glucose (BG) levels within the target range can be an elusive goal in children with type 1 diabetes mellitus (DM). To identify factor(s) that may contribute to glycemic instability, we analyzed the Continuous Glucose Monitoring System (CGMS) (Medtronic MiniMed, Northridge, CA) profiles of a group of children with type 1 DM and a history of frequent BG fluctuations and hypoglycemia. A total of 30 (17 girls, 13 boys) pediatric patients with a history of frequent BG fluctuations and hypoglycemia (mean age, 10.5 +/- 0.7 years; duration, 5.0 +/- 0.6 years), on three to four injections of insulin daily or insulin pump therapy, were evaluated by the CGMS. The mean BG (MBG), absolute means of daily differences (MODD), mean amplitude of glycemic excursion (MAGE), and number of hypoglycemic events (BG <60 mg/dL) for 48 h were calculated in each patient. There was a significant correlation between MBG and glycosylated hemoglobin (HbA1c) (r(2) = 0.22, p < 0.009). There was also a significant correlation between severity of lipohypertrophy and glycemic control (HbA1c) (r(2) = 0.20, p < 0.01). The MODD values had a positive correlation with the severity of injection site lipohypertrophy (r(2) = 0.37, p < 0.0003). The MAGE values had a positive correlation with bolus:basal insulin ratio (r(2) = 0.22, p < 0.009) and number of hypoglycemic events (r(2) = 0.21, p < 0.008), independent of age, MBG, and glycemic control. The 48-h CGMS profile can help characterize day-to-day and within-day BG variability and identify factors influencing glycemic instability in pediatric type 1 DM.

Retrograde type a dissection in a 24th gestational week pregnant patient - the importance of interdisciplinary interaction to a successful outcome.

PubMed

Easo, Jerry; Horst, Michael; Schmuck, Bernhard; Thomas, Rohit Philip; Saupe, Steffen; Book, Malte; Weymann, Alexander

2018-05-02

Type A Dissection in pregnancy is a devastating medical condition with 2 lives at stake and unclear strategy at early gestational stages. We describe a successful outcome, clearly dependent on the coordination of all involved disciplines. This case history describes a 28 year old female with a 24th week pregnancy gravida 2 para 0 with a DeBakey Type I aortic dissection, diagnosed via ultrasound. Surgery was perfomed on the day of diagnosis. After conferral with the mother, caesarean section was performed and a 690 g fetus could be delivered and was immediately transferred to the neonatal unit. Subsequent aortic repair was performed after hysterectomy, with replacement of the ascending aorta and hemiarch treatment. Intraoperatively no entry in the ascending aorta or transverse arch could be demonstrated, so that a retrograde Type A with entry distal to the left subclavian had to be postulated. We decided to perform subsequent computer tomography, demonstrating multiple entry sites in the descending aorta distal to the left subclavian artery. Successful endovascular treatment could be performed with a Medtronic Valiant Stent via a transfemoral approach. The further hospital stay was uneventful and the patient could be discharged on the 18th postoperative day. The baby demonstrated fighter qualities and could be discharged home after a 3 month hospital stay to be reunited with his mother. Prompt diagnosis, precise coordination between all involved subspecialties and ultimately, as in this case, definitive treatment in consensus with operative and interventional departments have led to a successful outcome and encourages us in our daily struggle in this often demanding surgery.

A comparative effectiveness analysis of three continuous glucose monitors: the Navigator, G4 Platinum, and Enlite.

PubMed

Damiano, Edward R; McKeon, Katherine; El-Khatib, Firas H; Zheng, Hui; Nathan, David M; Russell, Steven J

2014-07-01

The effectiveness and safety of continuous glucose monitors (CGMs) is dependent on their accuracy and reliability. The objective of this study was to compare 3 CGMs in adult and pediatric subjects with type 1 diabetes under closed-loop blood-glucose (BG) control. Twenty-four subjects (12 adults) with type 1 diabetes each participated in one 48-hour closed-loop BG control experiment. Venous plasma glucose (PG) measurements obtained every 15 minutes (4657 values) were paired in time with corresponding CGM glucose (CGMG) measurements obtained from 3 CGMs (FreeStyle Navigator, Abbott Diabetes Care; G4 Platinum, Dexcom; Enlite, Medtronic) worn simultaneously by each subject. The Navigator and G4 Platinum (G4) had the best overall accuracy, with an aggregate mean absolute relative difference (MARD) of all paired points of 12.3 ± 12.1% and 10.8 ± 9.9%, respectively. Both had lower MARDs of all paired points than Enlite (17.9 ± 15.8%, P < .005). Very large errors (MARD > 50%) were less common with the G4 (0.5%) than with the Enlite (4.3%, P = .0001) while the number of very large errors with the Navigator (1.4%) was intermediate between the G4 and Enlite (P = .1 and P = .06, respectively). The average MARD for experiments in adolescent subjects were lower than in adult subjects for the Navigator and G4, while there was no difference for Enlite. All 3 devices had similar reliability. A comprehensive head-to-head-to-head comparison of 3 CGMs revealed marked differences in both accuracy and precision. The Navigator and G4 were found to outperform the Enlite in these areas. © 2014 Diabetes Technology Society.

Use of continuous glucose monitoring as an outcome measure in clinical trials.

PubMed

Beck, Roy W; Calhoun, Peter; Kollman, Craig

2012-10-01

Although developed to be a management tool for individuals with diabetes, continuous glucose monitoring (CGM) also has potential value for the assessment of outcomes in clinical studies. We evaluated using CGM as such an outcome measure. Data were analyzed from six previously completed inpatient studies in which both CGM (Freestyle Navigator™ [Abbott Diabetes Care, Alameda, CA] or Guardian(®) [Medtronic, Northridge, CA]) and reference glucose measurements were available. The analyses included 97 days of data from 93 participants with type 1 diabetes (age range, 5-57 years; mean, 18 ± 12 years). Mean glucose levels per day were similar for the CGM and reference measurements (median, 148 mg/dL vs. 143 mg/dL, respectively; P = 0.92), and the correlation of the two was high (r = 0.89). Similarly, most glycemia metrics showed no significant differences comparing CGM and reference values, except that the nadir glucose tended to be slightly lower and peak glucose slightly higher with reference measurements than CGM measurements (respective median, 59 mg/dL vs. 66 mg/dL [P = 0.05] and 262 mg/dL vs. 257 mg/dL [P = 0.003]) and glucose variability as measured with the coefficient of variation was slightly lower with CGM than reference measurements (respective median, 31% vs. 35%; P<0.001). A reasonably high degree of concordance exists when comparing outcomes based on CGM measurements with outcomes based on reference blood glucose measurements. CGM inaccuracy and underestimation of the extremes of hyperglycemia and hypoglycemia can be accounted for in a clinical trial's study design. Thus, in appropriate settings, CGM can be a very meaningful and feasible outcome measure for clinical trials.

Occurrence of phrenic nerve stimulation in cardiac resynchronization therapy patients: the role of left ventricular lead type and placement site.

PubMed

Biffi, Mauro; Exner, Derek V; Crossley, George H; Ramza, Brian; Coutu, Benoit; Tomassoni, Gery; Kranig, Wolfgang; Li, Shelby; Kristiansen, Nina; Voss, Frederik

2013-01-01

Unwanted phrenic nerve stimulation (PNS) has been reported in ∼1 in 4 patients undergoing left ventricular (LV) pacing. The occurrence of PNS over mid-term follow-up and the significance of PNS are less certain. Data from 1307 patients enrolled in pre-market studies of LV leads manufactured by Medtronic (models 4193 and 4195 unipolar, 4194, 4196, 4296, and 4396 bipolar) were pooled. Left ventricular lead location was recorded at implant using a common classification scheme. Phrenic nerve stimulation symptoms were either spontaneously reported or identified at scheduled follow-up visits. A PNS-related complication was defined as PNS resulting in invasive intervention or the termination of LV pacing. Average follow-up was 14.9 months (range 0.0-46.6). Phrenic nerve stimulation symptoms occurred in 169 patients (12.9%). Phrenic nerve stimulation-related complications occurred in 21 of 1307 patients (1.6%); 16 of 738 (2.2%) in the unipolar lead studies, and 5 of 569 (0.9%) in the bipolar lead studies (P = 0.08). Phrenic nerve stimulation was more frequent at middle-lateral/posterior, and apical LV sites (139/1010) vs. basal-posterior/lateral/anterior, and middle-anterior sites (20/297; P= 0.01). As compared with an anterior LV lead position, a lateral LV pacing site was associated with over a four-fold higher risk of PNS (P= 0.005) and an apical LV pacing site was associated with over six-fold higher risk of PNS (P= 0.001). Phrenic nerve stimulation occurred in 13% of patients undergoing LV lead placement and was more common at mid-lateral/posterior, and LV apical sites. Most cases (123/139; 88%) of PNS were mitigated via electrical reprogramming, without the need for invasive intervention.

Transfemoral transcatheter aortic valve replacement compared with surgical replacement in patients with severe aortic stenosis and comparable risk: cost-utility and its determinants.

PubMed

Ribera, Aida; Slof, John; Andrea, Rut; Falces, Carlos; Gutiérrez, Enrique; Del Valle-Fernández, Raquel; Morís-de la Tassa, César; Mota, Pedro; Oteo, Juan Francisco; Cascant, Purificació; Altisent, Omar Abdul-Jawad; Sureda, Carlos; Serra, Vicente; García-Del Blanco, Bruno; Tornos, Pilar; Garcia-Dorado, David; Ferreira-González, Ignacio

2015-03-01

To evaluate cost-effectiveness of transfemoral TAVR vs surgical replacement (SAVR) and its determinants in patients with severe symptomatic aortic stenosis and comparable risk. Patients were prospectively recruited in 6 Spanish hospitals and followed up over one year. We estimated adjusted incremental cost-effectiveness ratio (ICER) (Euros per quality-adjusted life-year [QALY] gained) using a net-benefit approach and assessed the determinants of incremental net-benefit of TAVR vs SAVR. We analyzed data on 207 patients: 58, 87 and 62 in the Edwards SAPIEN (ES) TAVR, Medtronic-CoreValve (MC) TAVR and SAVR groups respectively. Average cost per patient of ES-TAVR was €8800 higher than SAVR and the gain in QALY was 0.036. The ICER was €148,525/QALY. The cost of MC-TAVR was €9729 higher than SAVR and the QALY difference was -0.011 (dominated). Results substantially changed in the following conditions: 1) in patients with high preoperative serum creatinine the ICERs were €18,302/QALY and €179,618/QALY for ES and MC-TAVR respectively; 2) a 30% reduction in the cost of TAVR devices decreased the ICER for ES-TAVR to €32,955/QALY; and 3) imputing hospitalization costs from other European countries leads to TAVR being dominant. In countries with relatively low health care costs TAVR is not likely to be cost-effective compared to SAVR in patients with intermediate risk for surgery, mainly because of the high cost of the valve compared to the cost of hospitalization. TAVR could be cost-effective in specific subgroups and in countries with higher hospitalization costs. Copyright © 2014 Elsevier Ireland Ltd. All rights reserved.

The Hancock® Valved Conduit for Right Ventricular Outflow Tract Reconstruction in Sheep for Assessing New Devices.

PubMed

Carney, John P; Zhang, Lindsey M; Larson, Jeffrey J; Lahti, Matthew T; Robinson, Nicholas A; Dalmasso, Agustin P; Bianco, Richard W

2017-07-01

Xenograft conduits have been used successfully to repair congenital heart defects, but are prone to failure over time. Hence, in order to improve patient outcomes, better xenografts are being developed. When evaluating a conduit's performance and safety it must first be compared against a clinically available control in a large animal model. The study aim was to evaluate a clinically available xenograft conduit used in right ventricular outflow tract (RVOT) reconstruction in a sheep model. RVOT reconstruction was performed in 13 adult and juvenile sheep, using the Medtronic Hancock® Bioprosthetic Valved Conduit (Hancock conduit). The method had previously been used on patients, and a newly modified variant termed 'RVOT Extraction' was employed to facilitate the surgical procedure. Animals were monitored over predetermined terms of 70 to 140 days. Serial transthoracic echocardiography, intracardiac pressure measurements and angiography were performed. On study completion the animals were euthanized and necropsies performed. Two animals died prior to their designated study term due to severe valvular stenosis and distal conduit narrowing, respectively. Thus, 11 animals survived the study term, with few or no complications. Generally, maximal and mean transvalvular pressure gradients across the implanted conduits were increased throughout the postoperative course. Among 11 full-term animals, seven conduits were patent with mild or no pseudointimal proliferation and with flexible leaflets maintaining the hemodynamic integrity of the valve. RVOT reconstruction using the Hancock conduit was shown to be successful in sheep, with durable and efficient performances. With its extensive clinical use in patients, and ability for long-term use in sheep (as described in the present study) it can be concluded that the Hancock conduit is an excellent control device for the evaluation of new xenografts in future preclinical studies.

Treating resistant hypertension with new devices.

PubMed

Wienemann, H; Meincke, F; Kaiser, L; Heeger, C H; Bergmann, M W

2014-06-01

Arterial hypertension is a frequent, chronic disease, which is one of the main risk factor for cardiovascular and renal diseases such as heart failure, chronic kidney disease, hypertensive heart disease, stroke as well as cardiac arrhythmias. In the clinical setting it remains challenging to accomplish the thresholds of guideline blood pressure (BP) levels now defined as office based BP to be below <140 mmHg. Patients on three or more antihypertensive drugs, with systolic BP values above ≥160 mmHg (≥150 mmHg for patients with type 2 diabetes) are classified as having resistant hypertension. In the past six years the development of interventional sympathetic renal artery denervation (RDN) opened a new treatment option targeting the afferent and efferent sympathetic nerves of the kidney to reduce BP. A large variety of devices are available on the market. Newly developed devices try to focus on new strategies such as ultrasound or irrigated catheters, which might reduce the post-procedural complications and increase the success rate. The first generation SymplicityTM device (Medtronic, Palo Alto, CA, USA) was shown to be safe, with side effects rarely occurring. Clinical trials demonstrate that this procedure is successful in about 70% of patients. However current data from Simplicity HTN-3 with 25% african-americans and a massive BP-lowering effect in the control "sham" group was not able to find a significant effect in the overall patient cohort. Possibly devices which allow to safely destroy sympathetic renal innervation more efficiently might allow for a higher responder rate. Irrigated RDN and ultrasound devices could deliver more energy to deeper tissue levels. This article provides an overview of currently available data on devices.

CorVue algorithm efficacy to predict heart failure in real life: Unnecessary and potentially misleading information?

PubMed

Palfy, Julia Anna; Benezet-Mazuecos, Juan; Milla, Juan Martinez; Iglesias, Jose Antonio; de la Vieja, Juan Jose; Sanchez-Borque, Pepa; Miracle, Angel; Rubio, Jose Manuel

2018-06-01

Heart failure (HF) hospitalizations have a negative impact on quality of life and imply important costs. Intrathoracic impedance (ITI) variations detected by cardiac devices have been hypothesized to predict HF hospitalizations. Although Optivol™ algorithm (Medtronic) has been widely studied, CorVue™ algorithm (St. Jude Medical) long term efficacy has not been systematically evaluated in a "real life" cohort. CorVue™ was activated in ICD/CRT-D patients to store information about ITI measures. Clinical events (new episodes of HF requiring treatment and hospitalizations) and CorVue™ data were recorded every three months. Appropriate CorVue™ detection for HF was considered if it occurred in the four prior weeks to the clinical event. 53 ICD/CRT-D (26 ICD and 27 CRT-D) patients (67±1 years-old, 79% male) were included. Device position was subcutaneous in 28 patients. At inclusion, mean LVEF was 25±7% and 27 patients (51%) were in NYHA class I, 18 (34%) class II and 8 (15%) class III. After a mean follow-up of 17±9 months, 105 ITI drops alarms were detected in 32 patients (60%). Only six alarms were appropriate (true positive) and required hospitalization. Eighteen patients (34%) presented 25 clinical episodes (12 hospitalizations and 13 ER/ambulatory treatment modifications). Nineteen of these clinical episodes (76%) remained undetected by the CorVue™ (false negative). Sensitivity of CorVue™ resulted in 24%, specificity was 70%, positive predictive value of 6% and negative predictive value of 93%. CorVue™ showed a low sensitivity to predict HF events. Therefore, routinely activation of this algorithm could generate misleading information. This article is protected by copyright. All rights reserved. This article is protected by copyright. All rights reserved.

Predicting Glucose Sensor Behavior in Blood Using Transport Modeling: Relative Impacts of Protein Biofouling and Cellular Metabolic Effects

PubMed Central

Novak, Matthew T.; Yuan, Fan; Reichert, William M.

2013-01-01

Background Tissue response to indwelling glucose sensors remains a confounding barrier to clinical application. While the effects of fully formed capsular tissue on sensor response have been studied, little has been done to understand how tissue interactions occurring before capsule formation hinder sensor performance. Upon insertion in subcutaneous tissue, the sensor is initially exposed to blood, blood borne constituents, and interstitial fluid. Using human whole blood as a simple ex vivo experimental system, the effects of protein accumulation at the sensor surface (biofouling effects) and cellular consumption of glucose in both the biofouling layer and in the bulk (metabolic effects) on sensor response were assessed. Methods Medtronic MiniMed SofSensor glucose sensors were incubated in whole blood, plasma-diluted whole blood, and cell-free platelet-poor plasma (PPP) to analyze the impact of different blood constituents on sensor function. Experimental conditions were then simulated using MATLAB to predict the relative impacts of biofouling and metabolic effects on the observed sensor responses. Results Protein biofouling in PPP in both the experiments and the simulations was found to have no interfering effect upon sensor response. Experimental results obtained with whole and dilute blood showed that the sensor response was markedly affected by blood borne glucose-consuming cells accumulated in the biofouling layer and in the surrounding bulk. Conclusions The physical barrier to glucose transport presented by protein biofouling does not hinder glucose movement to the sensor surface, and the consumption of glucose by inflammatory cells, and not erythrocytes, proximal to the sensor surface has a substantial effect on sensor response and may be the main culprit for anomalous sensor behavior immediately following implantation. PMID:24351181

An individual patient meta-analysis of five randomized trials assessing the effects of cardiac resynchronization therapy on morbidity and mortality in patients with symptomatic heart failure.

PubMed

Cleland, John G; Abraham, William T; Linde, Cecilia; Gold, Michael R; Young, James B; Claude Daubert, J; Sherfesee, Lou; Wells, George A; Tang, Anthony S L

2013-12-01

Cardiac resynchronization therapy (CRT) with or without a defibrillator reduces morbidity and mortality in selected patients with heart failure (HF) but response can be variable. We sought to identify pre-implantation variables that predict the response to CRT in a meta-analysis using individual patient-data. An individual patient meta-analysis of five randomized trials, funded by Medtronic, comparing CRT either with no active device or with a defibrillator was conducted, including the following baseline variables: age, sex, New York Heart Association class, aetiology, QRS morphology, QRS duration, left ventricular ejection fraction (LVEF), and systolic blood pressure. Outcomes were all-cause mortality and first hospitalization for HF or death. Of 3782 patients in sinus rhythm, median (inter-quartile range) age was 66 (58-73) years, QRS duration was 160 (146-176) ms, LVEF was 24 (20-28)%, and 78% had left bundle branch block. A multivariable model suggested that only QRS duration predicted the magnitude of the effect of CRT on outcomes. Further analysis produced estimated hazard ratios for the effect of CRT on all-cause mortality and on the composite of first hospitalization for HF or death that suggested increasing benefit with increasing QRS duration, the 95% confidence bounds excluding 1.0 at ∼140 ms for each endpoint, suggesting a high probability of substantial benefit from CRT when QRS duration exceeds this value. QRS duration is a powerful predictor of the effects of CRT on morbidity and mortality in patients with symptomatic HF and left ventricular systolic dysfunction who are in sinus rhythm. QRS morphology did not provide additional information about clinical response. NCT00170300, NCT00271154, NCT00251251.

Hypoglycemia Prevention and User Acceptance of an Insulin Pump System with Predictive Low Glucose Management.

PubMed

Choudhary, Pratik; Olsen, Birthe S; Conget, Ignacio; Welsh, John B; Vorrink, Linda; Shin, John J

2016-05-01

The MiniMed 640G sensor-augmented insulin pump system (Medtronic, Inc., Northridge, CA) can automatically suspend insulin delivery in advance of predicted hypoglycemia and restart it upon recovery. The aims of this analysis were to determine the rate at which predicted hypoglycemia was avoided with this strategy, as well as to assess user acceptance of the system and its insulin management features. Forty subjects with type 1 diabetes used the system for 4 weeks. We retrospectively evaluated performance of the system, using downloaded pump and sensor data, and evaluated user acceptance via questionnaires. There were 2,322 suspend before low events (2.1 per subject-day). The mean (± SD) duration of pump suspension events was 56.4 ± 9.6 min, and the mean subsequent sensor glucose (SG) nadir was 71.8 ± 5.2 mg/dL. SG values following 1,930 (83.1%) of the predictive suspensions did not reach the preset low limit. Nadir SG values of ≤50 and ≤60 mg/dL were seen in 207 (8.9%) and 356 (15.3%) of the predictive suspensions, respectively. Blood glucose (BG) and SG values before and during the study were comparable (P > 0.05). The mean absolute relative difference between paired SG and BG values was 10.9 ± 13.8%. Subjects felt confident using the system, agreed that it helped protect them from hypoglycemia, and wished to continue using it. Automatic insulin pump suspension as implemented in the MiniMed 640G system can help patients avoid hypoglycemia, without significantly increasing hyperglycemia.

Mid-Term Vascular Safety of Renal Denervation Assessed by Follow-up MR Imaging

DOE Office of Scientific and Technical Information (OSTI.GOV)

Schmid, Axel, E-mail: axel.schmid@uk-erlangen.de; Schmieder, Raphael; Lell, Michael

Background/AimsRenal denervation (RDN) emerged as a treatment option for reducing blood pressure (BP) in patients with treatment-resistant hypertension (TRH). However, concerns have been raised regarding the incidence of late renal artery stenosis or thromboembolism after RDN. The goal of the current study was, therefore, to conduct a prospective clinical trial on the mid-term vascular integrity of the renal arteries and the perfusion of the renal parenchyma assessed by magnetic resonance imaging (MRI) in the follow-up after catheter-based RDN.MethodsIn our single-centre investigator initiated study, 51 patients with true TRH underwent catheter-based RDN using the Symplicity Flex{sup TM} catheter (Medtronic Inc., Palomore » Alto, CA). Follow-up MRI was performed at a median of 11 months (interquartile range 6–18 months) after RDN on a 1.5T MR unit. High-resolution MR angiography (MRA) and MRI results were compared to the baseline digital angiography of renal arteries obtained at time of RDN. In case of uncertainties (N = 2) catheter angiography was repeated.ResultsBoth office and 24-h ambulatory BP were significantly reduced 6 and 12 months after RDN. Renal function remained unchanged 6 and 12 months after RDN. In all patients, MRA excluded new or progression of pre-existing low grade renal artery stenosis as well as focal aneurysms at the sites of radiofrequency ablation. In none of the patients new segmental perfusion deficits in either kidney were detected on MRI.ConclusionsNo vascular or parenchymal complications after radiofrequency-based RDN were detected in 51 patients followed up by MRI.« less

Utility of esophageal temperature monitoring during pulmonary vein isolation for atrial fibrillation using duty-cycled phased radiofrequency ablation.

PubMed

Deneke, Thomas; Bünz, Kathrin; Bastian, Annely; Päsler, Marcus; Anders, Helge; Lehmann, Rainer; Meuser, Wolfgang; de Groot, Joris R; Horlitz, Marc; Haberkorn, Ron; Mügge, Andreas; Shin, Dong-In

2011-03-01

A novel ablation system has been introduced for rapid treatment of atrial fibrillation (AF). This system delivers duty-cycled phased radiofrequency (RF) energy via an over-the-wire catheter (PVAC® , Medtronic) to achieve pulmonary vein (PV) isolation. Lower power and depth control suggests that collateral damage might be minimized. However, no studies have investigated the potential for thermal effect and damage to the esophagus. Ninety consecutive patients undergoing PV-isolation were evaluated. Group A (48 patients) had continuous luminal esophageal temperature (LET) monitoring using a temperature probe with 3 metal electrodes located in the vicinity of the targeted PV ostia. Ablation ceased when LET exceeded 40 °C. Only patients with LET ≥ 39 °C underwent endoscopic evaluation to assess esophageal damage. Group B (42 patients) excluded LET monitoring but all patients underwent endoscopy. In Group A, 27 (56%) patients showed LET ≥ 39 °C (mean LET 40.5 °C). Endoscopy revealed esophageal alterations in 5 (8%) (3 erythema and 2 intramural bleeding). One hundred eighty-nine out of 190 (99.5%) targeted PVs were successfully isolated, with 1 PV unsuccessful due to high LET. In Group B all 165 targeted PVs (100%) were successfully isolated. Endoscopy in Group 2 revealed no esophageal alterations. Using a duty-cycled, phased RF ablation system is safe and effective to isolate PVs. No Eso alteration was documented after ablation when LET was not monitored. This suggests that the LET probe may contribute to the thermal effect. Whether the documented increments in LET are due to direct tissue heating or possible interaction between the LET probe requires further investigation. © 2010 Wiley Periodicals, Inc.

Oxygenator Safety Evaluation: A Focus on Connection Grip Strength and Arterial Temperature Measurement Accuracy

PubMed Central

Newland, Richard F.; Baker, Robert A.; Sanderson, Andrew J.; Tuble, Sigrid C.; Tully, Phil J.

2012-01-01

Abstract: This report describes the assessment of three specific safety-related specifications in the consideration of an alternate oxygenator; first the grip strength relationship between various oxygenator connectors and SMARxT® tubing, second, the grip strength of various biopassive tubings and an isolated SMARxT® connector, and finally, the accuracy of the arterial outlet temperature measurement. Grip strength experiments for the connections between the SMARxT® tubing and the venous reservoir outlet and the oxygenator venous inlet and oxygenator arterial outlet of the Medtronic Affinity®, Sorin Synthesis®, Sorin Primox®, and Terumo Capiox® RX25 oxygenators were performed. In addition we compared the grip strength of polyvinyl chloride, Physio®, Trillium®, Carmeda®, X-Coating®, and SMARxT® tubing. The accuracy of the integrated arterial outlet temperature probes was determined by comparing the temperatures measured by the integrated probe with a precision reference thermometer. Connector grip strength comparisons for the evaluation oxygenators with SMARxT® tubing showed significant variation between oxygenators and connections (p = .02). Evaluation of the arterial outlet showed significant variation between evaluation oxygenators, while at the venous reservoir outlet and oxygenator inlet, there were no significant differences. Grip strength comparison data for the various tubing types demonstrated a main effect for tubing type F(5, 18) = 8.01, p = .002, ηp2 = .77. Temperature accuracy measurements demonstrated that all oxygenators overread the arterial outlet temperature at 15°C, whilst at temperatures ≥25°C, all oxygenators underread the arterial outlet temperature. The integrity of SMARxT® tubing connection is influenced by the connector type, and may decline over time, highlighting the importance to not consider interchanging components of the bypass circuit as inconsequential. PMID:22893983

Lumenless pacing leads: performance and extraction in pediatrics and congenital heart disease.

PubMed

Garnreiter, Jason; Whitaker, Patricia; Pilcher, Thomas; Etheridge, Susan; Saarel, Elizabeth

2015-01-01

Pediatric and congenital heart disease (CHD) patients requiring permanent pacing present unique challenges, including need for long duration of implant, small size, and structural abnormalities. We report 6 years of experience with a novel 4.1-Fr lumenless pacing lead (model 3830, Medtronic Inc., Minneapolis, MN, USA) in this population. Retrospective review of M3830 leads implanted at a pediatric center from 2005 to 2011. Data were compared to a population with a conventional pacing lead (model 1488, St. Jude Medical Inc., St. Paul, MN, USA). A total of 193 patients with 198 model 3830 leads (125 atrial, 73 ventricular) were enrolled. CHD was present in 121 (63%). Age and weight at implant were 16.6 ± 8.5 years and 51.7 ± 23.5 kg, respectively. Length of follow-up was 26 ± 19 months (range 0-73). At implant, mean sensing and capture thresholds were good and remained stable over time. There were no significant differences in electrical performance compared to 101 leads in the comparison group. Implant complications were rare. Follow-up complications occurred in 4% of the M3830 leads and 16% of M1488 leads. Eleven M3830 leads required extraction. All were extracted without complications using only manual traction. There were three deaths in each group. One death in the M1488 group occurred during lead extraction. No other deaths were lead related. During up to 6 years of use in pediatric and CHD patients, the M3830 lead has demonstrated excellent efficacy, a low rate of complications, and straightforward extractability relative to traditional pacing leads. ©2014 Wiley Periodicals, Inc.

[The length of the piston in otosclerosis surgery].

PubMed

Portmann, D; Alcantara, M; Vianna, M

2007-01-01

The measurement of the piston is always described as a significant stage of the surgery but its length is never clearly defined. The goal of this work is to determine the length of the prosthesis. From May 2003 to May 2005, 128 patients with otosclerosis, diagnosed on the basis of their clinical history and their audiogram, were included in this prospective study. Some of them were revision surgeries. The prosthesis generally used was the Portmann piston clip (Medtronic Xomed Inc Portmann Piston Clip Stainless Steel/Fluoroplastic). In stapedectomies, a Teflon piston of 0.6 mm of diameter was used (Pouret Company Fluoroplastic Stapes Prosthesis). These prostheses must be trimmed before their installation. The measurement technique is described. The length of the prosthesis was increased by 0.5 mm to include the thickness of the footplate. The Portmann piston clip was used 116 times (100 initial surgeries and 16 revisions surgeries) and the Teflon prosthesis of 0.6 mm of diameter only 13 times (6 primary stapedectomies and 7 revisions stapedectomies). The length of the prosthesis was between 3,5 mm and 5 mm. In the majority of cases, the length of the prosthesis was 4.75 mm (62 patients, 48.1%), followed by 4.5 mm (29 patients, 22.5%) and 5 mm (27 patients, 20.9%). In eleven cases (8.5%) the prosthesis measured less than 4,5 mm. None of the patients in this study experienced a postoperative sensorineural hearing loss. The measurement of the length of the piston is very significant, and in our study the majority of the pistons were cut at 4.75 mm which indicates an incus-footplate measurement of 4.25 mm.

Neurostimulation systems for deep brain stimulation: in vitro evaluation of magnetic resonance imaging-related heating at 1.5 tesla.

PubMed

Rezai, Ali R; Finelli, Daniel; Nyenhuis, John A; Hrdlicka, Greg; Tkach, Jean; Sharan, Ashwini; Rugieri, Paul; Stypulkowski, Paul H; Shellock, Frank G

2002-03-01

To assess magnetic resonance imaging (MRI)-related heating for a neurostimulation system (Activa Tremor Control System, Medtronic, Minneapolis, MN) used for chronic deep brain stimulation (DBS). Different configurations were evaluated for bilateral neurostimulators (Soletra Model 7426), extensions, and leads to assess worst-case and clinically relevant positioning scenarios. In vitro testing was performed using a 1.5-T/64-MHz MR system and a gel-filled phantom designed to approximate the head and upper torso of a human subject. MRI was conducted using the transmit/receive body and transmit/receive head radio frequency (RF) coils. Various levels of RF energy were applied with the transmit/receive body (whole-body averaged specific absorption rate (SAR); range, 0.98-3.90 W/kg) and transmit/receive head (whole-body averaged SAR; range, 0.07-0.24 W/kg) coils. A fluoroptic thermometry system was used to record temperatures at multiple locations before (1 minute) and during (15 minutes) MRI. Using the body RF coil, the highest temperature changes ranged from 2.5 degrees-25.3 degrees C. Using the head RF coil, the highest temperature changes ranged from 2.3 degrees-7.1 degrees C.Thus, these findings indicated that substantial heating occurs under certain conditions, while others produce relatively minor, physiologically inconsequential temperature increases. The temperature increases were dependent on the type of RF coil, level of SAR used, and how the lead wires were positioned. Notably, the use of clinically relevant positioning techniques for the neurostimulation system and low SARs commonly used for imaging the brain generated little heating. Based on this information, MR safety guidelines are provided. These observations are restricted to the tested neurostimulation system.

Hemolytic performance of a MagLev disposable rotary blood pump (MedTech Dispo): effects of MagLev gap clearance and surface roughness.

PubMed

Hoshi, Hideo; Asama, Junichi; Hijikata, Wataru; Hara, Chikara; Shinshi, Tadahiko; Yasuda, Toshitaka; Ohuchi, Katsuhiro; Shimokohbe, Akira; Takatani, Setsuo

2006-12-01

Mechanical shaft seal bearing incorporated in the centrifugal blood pumps contributes to hemolysis and thrombus formation. In addition, the problem of durability and corrosion of mechanical shaft seal bearing has been recently reported from the safety point of view. To amend the shortcomings of the blood-immersed mechanical bearings, a magnetic levitated centrifugal rotary blood pump (MedTech Dispo Model 1; Tokyo Medical and Dental University, Tokyo, Japan) has been developed for extracorporeal disposable application. In this study, the hemolytic performance of the MedTech Dispo Model 1 centrifugal blood pump system was evaluated, with special focus on the narrow blood path clearance at the magnetic bearing between rotor and stator, and on the pump housing surface roughness. A pump flow of 5 L/min against the head pressure of 100 mm Hg for 4 h was included in the hemolytic test conditions. Anticoagulated fresh porcine blood was used as a working fluid. The clearance of blood path at the magnetic bearing was in the range of 100-250 micro m. Pump housing surface roughness was controlled to be around Ra = 0.1-1.5 micro m. The lowest hemolytic results were obtained at the clearance of 250 micro m and with the polished surface (Ra = 0.1 micro m) yielding the normalized index of hemolysis (NIH) of less than 0.001 g/100 L, which was 1/5 of the Biopump BP-80 (Medtronic Inc., Minneapolis, MN, USA, and 1/4 of the BPX-80. In spite of rough surface and narrow blood path, NIH levels were less than clinically acceptable level of 0.005 g/100 L. The noncontact, levitated impeller system is useful to improve pump performance in blood environment.

Intraoperative monitoring of the recurrent laryngeal nerve by vagal nerve stimulation in thyroid surgery.

PubMed

Farizon, Brigitte; Gavid, Marie; Karkas, Alexandre; Dumollard, Jean-Marc; Peoc'h, Michel; Prades, Jean-Michel

2017-01-01

The aim of the present study was to evaluate the thyroarytenoid muscle response during bilateral thyroid surgery using vagal nerve stimulation. 195 patients (390 nerves at risk) underwent a total thyroidectomy. The recurrent laryngeal nerve's function was checked by analyzing the amplitude and the latency of the thyroarytenoid muscle's responses after a vagal nerve's stimulation (0.5 and 1 mA) using the NIM3 Medtronic system. All patients were submitted to preoperative and postoperative laryngoscopy. 20 patients get no thyroarytenoid muscle response to the vagal nerve stimulation, and 14 postoperative recurrent laryngeal nerve palsies were confirmed (3.8 %). Two palsies were present after 6 months (0.51 %). All the patients with muscle's response have normal mobility vocal fold. The test sensitivity was 100 % and the test specificity was 98 %. Physiologically, the mean latencies of the muscular potentials for the right RLN were, respectively, 3.89 and 3.83 ms (p > 0.05) for the stimulation at 0.5 and 1 mA. The mean latencies for the left RLN were, respectively, 6.25 and 6.22 ms for the stimulation at 0.5 and 1 mA (p > 0.05). The difference of the latencies between the right and the left nerve was 2.30 ms (1.75-3.25 ms) with a stimulation of 0.5 or 1 mA (p < 0.05). Thyroarytenoid muscle's response via a vagal nerve stimulation showed a functional asymmetry of the laryngeal adduction with a faster right response. Surgically, this method can predict accurately an immediate postoperative vocal folds function in patients undergoing a bilateral thyroid surgery.

Numerical and clinical precision of continuous glucose monitoring in Colombian patients treated with insulin infusion pump with automated suspension in hypoglycemia.

PubMed

Gómez, Ana M; Marín Sánchez, Alejandro; Muñoz, Oscar M; Colón Peña, Christian Alejandro

2015-12-01

Insulin pump therapy associated with continuous glucose monitoring has shown a positive clinical impact on diabetes control and reduction of hypoglycemia episodes. There are descriptions of the performance of this device in other populations, but its precision and accuracy in Colombia and Latin America are unknown, especially in the routine outpatient setting. Data from 33 type 1 and type 2 diabetes patients with sensor-augmented pump therapy with threshold suspend automation, MiniMed Paradigm® Veo™ (Medtronic, Northridge, California), managed at Hospital Universitario San Ignacio (Bogotá, Colombia) and receiving outpatient treatment, were analyzed. Simultaneous data from continuous glucose monitoring and capillary blood glucose were compared, and their precision and accuracy were calculating with different methods, including Clarke error grid. Analyses included 2,262 continuous glucose monitoring -reference paired glucose values. A mean absolute relative difference of 20.1% was found for all measurements, with a value higher than 23% for glucose levels ≤75mg/dL. Global compliance with the ISO criteria was 64.9%. It was higher for values >75mg/dl (68.3%, 1,308 of 1,916 readings), than for those ≤ 75mg/dl (49.4%, 171 of 346 readings). Clinical accuracy, as assessed by the Clarke error grid, showed that 91.77% of data were within the A and B zones (75.6% in hypoglycemia). A good numerical accuracy was found for continuous glucose monitoring in normo and hyperglycemia situations, with low precision in hypoglycemia. The clinical accuracy of the device was adequate, with no significant safety concerns for patients. Copyright © 2015 SEEN. Published by Elsevier España, S.L.U. All rights reserved.

Electromagnetic interference from electronic devices used in the management of type 1 diabetes can impair the performance of an avalanche transceiver in search mode.

PubMed

Miller, Steven C M

2015-06-01

Portable electronic devices play an important role in the management of type 1 diabetes mellitus. Electromagnetic interference from electronic devices has been shown to impair the function of an avalanche transceiver in search mode (but not in transmitting mode). This study investigates the influence of electromagnetic interference from diabetes devices on a searching avalanche beacon. The greatest distance at which an avalanche transceiver (in search mode) could accurately indicate the location of a transmitting transceiver was assessed when portable electronic devices (including an insulin pump and commonly used real-time continuous subcutaneous glucose monitoring system [rtCGMS]) were held in close proximity to each transceiver. The searching transceiver could accurately locate a transmitted signal at a distance of 30 m when used alone. This distance was unchanged by the Dexcom G4 rtCGMS, but was reduced to 10 m when the Medtronic Guardian rtCGMS was held close (within 30 cm) to the receiving beacon. Interference from the Animas Vibe insulin pump reduced this distance to 5 m, impairing the searching transceiver in a manner identical to the effect of a cell phone. Electromagnetic interference produced by some diabetes devices when held within 30 cm of a searching avalanche transceiver can impair the ability to locate a signal. Such interference could significantly compromise the outcome of a companion rescue scenario. Further investigation using other pumps and rtCGMS devices is required to evaluate all available diabetes electronics. Meantime, all electronic diabetes devices including rtCGMS and insulin pumps should not be used within 30 cm of an avalanche transceiver. Copyright © 2015 Wilderness Medical Society. Published by Elsevier Inc. All rights reserved.

Effect of Smaller Left Ventricular Capture Threshold Safety Margins to Improve Device Longevity in Recipients of Cardiac Resynchronization-Defibrillation Therapy.

PubMed

Steinhaus, Daniel A; Waks, Jonathan W; Collins, Robert; Kleckner, Karen; Kramer, Daniel B; Zimetbaum, Peter J

2015-07-01

Device longevity in cardiac resynchronization therapy (CRT) is affected by the pacing capture threshold (PCT) and programmed pacing amplitude of the left ventricular (LV) pacing lead. The aims of this study were to evaluate the stability of LV pacing thresholds in a nationwide sample of CRT defibrillator recipients and to determine potential longevity improvements associated with a decrease in the LV safety margin while maintaining effective delivery of CRT. CRT defibrillator patients in the Medtronic CareLink database were eligible for inclusion. LV PCT stability was evaluated using ≥2 measurements over a 14-day period. Separately, a random sample of 7,250 patients with programmed right atrial and right ventricular amplitudes ≤2.5 V, LV thresholds ≤ 2.5 V, and LV pacing ≥90% were evaluated to estimate theoretical battery longevity improvement using LV safety margins of 0.5 and 1.5 V. Threshold stability analysis in 43,256 patients demonstrated LV PCT stability of <0.5 V in 77% of patients and <1 V in 95%. Device longevity analysis showed that the use of a 0.5-V safety margin increased average battery longevity by 0.62 years (95% confidence interval 0.61 to 0.63) compared with a safety margin of 1.5 V. Patients with LV PCTs >1 V had the greatest increases in battery life (mean increase 0.86 years, 95% confidence interval 0.85 to 0.87). In conclusion, nearly all CRT defibrillator patients had LV PCT stability <1.0 V. Decreasing the LV safety margin from 1.5 to 0.5 V provided consistent delivery of CRT for most patients and significantly improved battery longevity. Copyright © 2015 Elsevier Inc. All rights reserved.

Is the failure of SYMPLICITY HTN-3 trial to meet its efficacy endpoint the "end of the road" for renal denervation?

PubMed

Epstein, Murray; de Marchena, Eduardo

2015-02-01

Resistant hypertension is a common medical problem that is increasing with the advent of an increasingly older and heavier population. The etiology of resistant hypertension is almost always multifactorial, but the results of numerous studies indicate that renal sympathetic activation is a particularly common cause of resistance to antihypertensive treatment. Consistent with the belief in a pivotal role of renal sympathetic stimulation, there has been a growing interest in renal denervation (RDN) treatment strategies. The long-awaited results of SYMPLICITY HTN-3 study disclosed that the reduction in blood pressure by the SYMPLICITY device did not differ from that in the sham-procedure arm of the study. In the present article, we identify several factors that explain why the study failed to demonstrate any benefit from the intervention. The reasons are multifactorial and include inadequate screening at entry and frequent medication changes during the study. Additional problems include the lack of experience of many operators with the SYMPLICITY device and procedure variability, as attested to by a diminished number of ablation "quadrants." Also a factor was the inability of the first generation Medtronic device to allow four ablations to be performed simultaneously. We recommend that future RDN studies adhere to more rigorous screening procedures, and utilize newer multi-site denervation systems that facilitate four ablations simultaneously. Drug optimization should be achieved by monitoring adherence throughout the study. Nevertheless, we are optimistic about a future role of RDN. To optimize chances of success, increased efforts are necessary to identify the appropriate patients for RDN and investigators must use second and third generation denervation devices and techniques. Copyright © 2015 American Society of Hypertension. Published by Elsevier Inc. All rights reserved.

Randomized sham-controlled trial of renal sympathetic denervation in mild resistant hypertension.

PubMed

Desch, Steffen; Okon, Thomas; Heinemann, Diana; Kulle, Konrad; Röhnert, Karoline; Sonnabend, Melanie; Petzold, Martin; Müller, Ulrike; Schuler, Gerhard; Eitel, Ingo; Thiele, Holger; Lurz, Philipp

2015-06-01

Few data are available with regard to the effectiveness of renal sympathetic denervation in patients with resistant hypertension yet only mildly elevated blood pressure (BP). Patients with resistant hypertension and slightly elevated BP (day-time systolic pressure, 135-149 and diastolic pressure, 90-94 mm Hg on 24-hour ambulatory measurement) were randomized in a 1:1 ratio to renal sympathetic denervation with the Symplicity Flex Catheter (Medtronic) or an invasive sham procedure. The primary efficacy end point was the change in 24-hour systolic BP at 6 months between groups in the intention to treat population. A total of 71 patients underwent randomization. Baseline day-time systolic BP was 144.4±4.8 mm Hg in patients assigned to denervation and 143.0±4.7 mm Hg in patients randomized to the sham procedure. The mean change in 24-hour systolic BP in the intention to treat cohort at 6 months was -7.0 mm Hg (95% confidence interval, -10.8 to -3.2) for patients undergoing denervation and -3.5 mm Hg (95% confidence interval, -6.7 to -0.2) in the sham group (P=0.15). In the per protocol population, the change in 24-hour systolic BP at 6 months was -8.3 mm Hg (95% confidence interval, -11.7 to -5.0) for patients undergoing denervation and -3.5 mm Hg (95% confidence interval, -6.8 to -0.2) in the sham group (P=0.042). In patients with mild resistant hypertension, renal sympathetic denervation failed to show a significant reduction in the primary end point of 24-hour systolic BP at 6 months between groups in the intention to treat analysis. URL: http://www.clinicaltrials.gov. Unique identifier: NCT01656096. © 2015 American Heart Association, Inc.

Denervation (ablation) of nerve terminalis in renal arteries: early results of interventional treatment of arterial hypertension in Poland.

PubMed

Bartuś, Krzysztof; Sadowski, Jerzy; Kapelak, Bogusław; Zajdel, Wojciech; Godlewski, Jacek; Bartuś, Stanisław; Bochenek, Maciej; Bartuś, Magdalena; Żmudka, Krzysztof; Sobotka, Paul A

2013-01-01

Arterial hypertension is one of the main causes of cardiovascular disease morbidity and overall mortality. To report the single centre experiences with changes in arterial blood pressure (BP) in patients after intra-arterial application of radiofrequency (RF) energy to cause renal sympathetic efferent and somatic afferent nerve and report vascular and kidney safety in a six month follow up. Twenty-eight patients, with hypertension despite medical therapy (median age 52.02 years, range 42-72 years) consented to therapeutic renal nerve ablation. SIMPLICITY RF catheters and generator provided by Ardian (currently Medtronic Inc., USA) were used to perform renal artery angiography and ablation. The mean BP at baseline, and after one month, three months and six months were measured [mm Hg]: systolic 176.6; 162.3 (p = 0.004); 150.6 (p < 0.001); 147.2 (p < 0.001); diastolic 100.2; 90.3 (p < 0.001); 91.79 (p = 0.03); 88.5 (p < 0.001); pulse pressure 76.57; 75.18 (p = NS); 65.80 (p < 0.001); 62.15 (p < 0.001). Neither procedure-related nor therapy-related complications were reported in the six month follow up. In our cohort of patients, intra-arterial renal nerve denervation was not associated with either vascular or renal complications out to six months. Nerve ablation of renal arteries led to significant reduction of mean values of arterial systolic, diastolic BP and significant reduction of pulse pressure. The Polish experience is not significantly different compared to that reported in the Symplicity I and Symplicity II international cohorts. The long term durability of this therapy and its application to earlier stages of hypertension or other disease states will require further investigation.

Local field potential recordings in a non-human primate model of Parkinsons disease using the Activa PC + S neurostimulator

PubMed Central

Connolly, Allison T; Muralidharan, Abirami; Hendrix, Claudia; Johnson, Luke; Gupta, Rahul; Stanslaski, Scott; Denison, Tim; Baker, Kenneth B; Vitek, Jerrold L; Johnson, Matthew D

2016-01-01

Objective Using the Medtronic Activa® PC + S system, this study investigated how passive joint manipulation, reaching behavior, and deep brain stimulation (DBS) modulate local field potential (LFP) activity in the subthalamic nucleus (STN) and globus pallidus (GP). Approach Five non-human primates were implanted unilaterally with one or more DBS leads. LFPs were collected in montage recordings during resting state conditions and during motor tasks that facilitate the expression of parkinsonian motor signs. These recordings were made in the naïve state in one subject, in the parkinsonian state in two subjects, and in both naïve and parkinsonian states in two subjects. Main results LFPs measured at rest were consistent over time for a given recording location and parkinsonian state in a given subject; however, LFPs were highly variable between subjects, between and within recording locations, and across parkinsonian states. LFPs in both naïve and parkinsonian states across all recorded nuclei contained a spectral peak in the beta band (10–30 Hz). Moreover, the spectral content of recorded LFPs was modulated by passive and active movement of the subjects’ limbs. LFPs recorded during a cued-reaching task displayed task-related beta desynchronization in STN and GP. The bidirectional capabilities of the Activa® PC + S also allowed for recording LFPs while delivering DBS. The therapeutic effect of STN DBS on parkinsonian rigidity outlasted stimulation for 30–60 s, but there was no correlation with beta band power. Significance This study emphasizes (1) the variability in spontaneous LFPs amongst subjects and (2) the value of using the Activa® PC + S system to record neural data in the context of behavioral tasks that allow one to evaluate a subject’s symptomatology. PMID:26469737

Towards eradication of inappropriate therapies for ICD lead failure by combining comprehensive remote monitoring and lead noise alerts.

PubMed

Ploux, Sylvain; Swerdlow, Charles D; Strik, Marc; Welte, Nicolas; Klotz, Nicolas; Ritter, Philippe; Haïssaguerre, Michel; Bordachar, Pierre

2018-06-02

Recognition of implantable cardioverter defibrillator (ICD) lead malfunction before occurrence of life threatening complications is crucial. We aimed to assess the effectiveness of remote monitoring associated or not with a lead noise alert for early detection of ICD lead failure. From October 2013 to April 2017, a median of 1,224 (578-1,958) ICD patients were remotely monitored with comprehensive analysis of all transmitted materials. ICD lead failure and subsequent device interventions were prospectively collected in patients with (RMLN) and without (RM) a lead noise alert (Abbott Secure Sense™ or Medtronic Lead Integrity Alert™) in their remote monitoring system. During a follow-up of 4,457 patient years, 64 lead failures were diagnosed. Sixty-one (95%) of the diagnoses were made before any clinical complication occurred. Inappropriate shocks were delivered in only one patient of each group (3%), with an annual rate of 0.04%. All high voltage conductor failures were identified remotely by a dedicated impedance alert in 10 patients. Pace-sense component failures were correctly identified by a dedicated alert in 77% (17 of 22) of the RMLN group versus 25% (8 of 32) of the RM group (P = 0.002). The absence of a lead noise alert was associated with a 16-fold increase in the likelihood of initiating either a shock or ATP (OR: 16.0, 95% CI 1.8-143.3; P = 0.01). ICD remote monitoring with systematic review of all transmitted data is associated with a very low rate of inappropriate shocks related to lead failure. Dedicated noise alerts further reduce inappropriate detection of ventricular arrhythmias. © 2018 Wiley Periodicals, Inc.

Towards real-time cardiovascular magnetic resonance guided transarterial CoreValve implantation: in vivo evaluation in swine

PubMed Central

2012-01-01

Background Real-time cardiovascular magnetic resonance (rtCMR) is considered attractive for guiding TAVI. Owing to an unlimited scan plane orientation and an unsurpassed soft-tissue contrast with simultaneous device visualization, rtCMR is presumed to allow safe device navigation and to offer optimal orientation for precise axial positioning. We sought to evaluate the preclinical feasibility of rtCMR-guided transarterial aortic valve implatation (TAVI) using the nitinol-based Medtronic CoreValve bioprosthesis. Methods rtCMR-guided transfemoral (n = 2) and transsubclavian (n = 6) TAVI was performed in 8 swine using the original CoreValve prosthesis and a modified, CMR-compatible delivery catheter without ferromagnetic components. Results rtCMR using TrueFISP sequences provided reliable imaging guidance during TAVI, which was successful in 6 swine. One transfemoral attempt failed due to unsuccessful aortic arch passage and one pericardial tamponade with subsequent death occurred as a result of ventricular perforation by the device tip due to an operating error, this complication being detected without delay by rtCMR. rtCMR allowed for a detailed, simultaneous visualization of the delivery system with the mounted stent-valve and the surrounding anatomy, resulting in improved visualization during navigation through the vasculature, passage of the aortic valve, and during placement and deployment of the stent-valve. Post-interventional success could be confirmed using ECG-triggered time-resolved cine-TrueFISP and flow-sensitive phase-contrast sequences. Intended valve position was confirmed by ex-vivo histology. Conclusions Our study shows that rtCMR-guided TAVI using the commercial CoreValve prosthesis in conjunction with a modified delivery system is feasible in swine, allowing improved procedural guidance including immediate detection of complications and direct functional assessment with reduction of radiation and omission of contrast media. PMID:22453050

Towards real-time cardiovascular magnetic resonance guided transarterial CoreValve implantation: in vivo evaluation in swine.

PubMed

Kahlert, Philipp; Parohl, Nina; Albert, Juliane; Schäfer, Lena; Reinhardt, Renate; Kaiser, Gernot M; McDougall, Ian; Decker, Brad; Plicht, Björn; Erbel, Raimund; Eggebrecht, Holger; Ladd, Mark E; Quick, Harald H

2012-03-27

Real-time cardiovascular magnetic resonance (rtCMR) is considered attractive for guiding TAVI. Owing to an unlimited scan plane orientation and an unsurpassed soft-tissue contrast with simultaneous device visualization, rtCMR is presumed to allow safe device navigation and to offer optimal orientation for precise axial positioning. We sought to evaluate the preclinical feasibility of rtCMR-guided transarterial aortic valve implatation (TAVI) using the nitinol-based Medtronic CoreValve bioprosthesis. rtCMR-guided transfemoral (n = 2) and transsubclavian (n = 6) TAVI was performed in 8 swine using the original CoreValve prosthesis and a modified, CMR-compatible delivery catheter without ferromagnetic components. rtCMR using TrueFISP sequences provided reliable imaging guidance during TAVI, which was successful in 6 swine. One transfemoral attempt failed due to unsuccessful aortic arch passage and one pericardial tamponade with subsequent death occurred as a result of ventricular perforation by the device tip due to an operating error, this complication being detected without delay by rtCMR. rtCMR allowed for a detailed, simultaneous visualization of the delivery system with the mounted stent-valve and the surrounding anatomy, resulting in improved visualization during navigation through the vasculature, passage of the aortic valve, and during placement and deployment of the stent-valve. Post-interventional success could be confirmed using ECG-triggered time-resolved cine-TrueFISP and flow-sensitive phase-contrast sequences. Intended valve position was confirmed by ex-vivo histology. Our study shows that rtCMR-guided TAVI using the commercial CoreValve prosthesis in conjunction with a modified delivery system is feasible in swine, allowing improved procedural guidance including immediate detection of complications and direct functional assessment with reduction of radiation and omission of contrast media.

Does Low-Field Intraoperative Magnetic Resonance Improve the Results of Endoscopic Pituitary Surgery? Experience of the Implementation of a New Device in a Referral Center.

PubMed

García, Sergio; Reyes, Luis; Roldán, Pedro; Torales, Jorge; Halperin, Irene; Hanzu, Felicia; Langdon, Cristobal; Alobid, Isam; Enseñat, Joaquim

2017-06-01

To assess the contribution of low-field intraoperative magnetic resonance (iMRI) to endoscopic pituitary surgery. We analyzed a prospective series of patients undergoing endoscopic endonasal surgery for pituitary macroadenomas assisted with a low-field iMRI (PoleStarN30, 0.15 T [Medtronic]). Clinical, radiologic, and surgical variables were analyzed and compared with our fully endoscopic historic cohort operated on without iMRI assistance. A bibliographic review of pituitary surgery assisted with iMRI was conducted. Thirty patients (57% female; mean age, 55 years) were prospectively analyzed. The most frequent tumor subtype was nonfunctioning macroadenoma (50%). The average Knosp grade was 2.3 and mean tumor size was 18 mm. Surgical and positioning time were 102 and 47 minutes, respectively. Hospital stay and complication rates were similar to our historical cohort for pituitary surgery. Mean follow-up was 10 months. Complete resection (CR) was achieved in 83% of patients. Seven patients (23%) benefited from iMRI assistance and achieved a CR in their surgeries. All patients except 1 experienced hormonal activity remission. iMRI sensitivity and specificity was 0.8 and 1, respectively. Although not statistically significant, CR rates were globally 11.5% superior in iMRI series compared with our historical cohort. This difference was independent of cavernous sinus invasiveness grade (CR rate increased 12.5% for Knosp grade 0-2 and 8.1% for Knosp grade 3-4). Low-field iMRI is a useful and safe assistance even in advanced surgical techniques such as endoscopy. Its contribution is limited by the intrinsic features of the tumor. Further randomized studies are required to confirm the cost-effectiveness of iMRI in pituitary surgery. Copyright © 2017 Elsevier Inc. All rights reserved.

Comparison of closed-cell and hybrid-cell stent designs in carotid artery stenting: clinical and procedural outcomes

PubMed Central

Tatli, Ersan; Vatan, Mehmet Bulent; Agac, Mustafa Tarik; Gunduz, Huseyin; Akdemir, Ramazan; Kilic, Harun

2017-01-01

Introduction Carotid artery stenting (CAS) is a promising alternative to surgery in high-risk patients. However, the impact of stent cell design on outcomes in CAS is a matter of continued debate. Aim To compare the periprocedural and clinical outcomes of different stent designs for CAS with distal protection devices. Material and methods All CAS procedures with both closed- and hybrid-cell stents performed at our institution between February 2010 and December 2015 were analyzed retrospectively. Adverse events were defined as death, major stroke, minor stroke, transient ischemic attack and myocardial infarction. Periprocedural and 30-day adverse events and internal carotid artery (ICA) vasospasm rates were compared between the closed-cell and hybrid-cell stent groups. Results The study included 234 patients comprising 146 patients with a closed-cell stent (Xact stent, Abbott Vascular) (mean age: 68.5 ±8.6; 67.1% male) and 88 patients with a hybrid-cell stent (Cristallo Ideale, Medtronic) (mean age: 67.2 ±12.8; 68.2% male). There was no significant difference between the groups with respect to periprocedural or 30-day adverse event rates. While there was no difference in terms of tortuosity index between the groups, there was a higher procedural ICA vasospasm rate in the closed-cell stent group (35 patients, 23%) compared with the hybrid-cell stent group (10 patients, 11%) (p = 0.017). Conclusions The results of this study showed no significant difference in the clinical adverse event rates after CAS between the closed-cell stent group and the hybrid-cell stent group. However, procedural ICA vasospasm was more common in the closed-cell stent group. PMID:28798784

Hybrid Closed-Loop Insulin Delivery in Type 1 Diabetes During Supervised Outpatient Conditions.

PubMed

Grosman, Benyamin; Ilany, Jacob; Roy, Anirban; Kurtz, Natalie; Wu, Di; Parikh, Neha; Voskanyan, Gayane; Konvalina, Noa; Mylonas, Chrystaleni; Gottlieb, Rebecca; Kaufman, Francine; Cohen, Ohad

2016-05-01

Efficacy and safety of the Medtronic Hybrid Closed-Loop (HCL) system were tested in subjects with type 1 diabetes in a supervised outpatient setting. The HCL system is a prototype research platform that includes a sensor-augmented insulin pump in communication with a control algorithm housed on an Android-based cellular device. Nine subjects with type 1 diabetes (5 female, mean age 53.3 years, mean A1C 7.2%) underwent 9 studies totaling 571 hours of closed-loop control using either default or personalized parameters. The system required meal announcements with estimates of carbohydrate (CHO) intake that were based on metabolic kitchen quantification (MK), dietician estimates (D), or subject estimates (Control). Postprandial glycemia was compared for MK, D, and Control meals. The overall sensor glucose mean was 145 ± 43, the overall percentage time in the range 70-180 mg/dL was 80%, the overall percentage time <70 mg/dL was 0.79%. Compared to intervals of default parameter use (225 hours), intervals of personalized parameter use (346 hours), sensor glucose mean was 158 ± 49 and 137 ± 37 mg/dL (P < .001), respectively, and included more time in range (87% vs 68%) and less time below range (0.54% vs 1.18%). Most subjects underestimated the CHO content of meals, but postprandial glycemia was not significantly different between MK and matched Control meals (P = .16) or between D and matched Control meals (P = .76). There were no episodes of severe hypoglycemia. The HCL system was efficacious and safe during this study. Personally adapted HCL parameters were associated with more time in range and less time below range than default parameters. Accurate estimates of meal CHO did not contribute to improved postprandial glycemia. © 2016 Diabetes Technology Society.

Local field potential recordings in a non-human primate model of Parkinsons disease using the Activa PC + S neurostimulator

NASA Astrophysics Data System (ADS)

Connolly, Allison T.; Muralidharan, Abirami; Hendrix, Claudia; Johnson, Luke; Gupta, Rahul; Stanslaski, Scott; Denison, Tim; Baker, Kenneth B.; Vitek, Jerrold L.; Johnson, Matthew D.

2015-12-01

Objective. Using the Medtronic Activa® PC + S system, this study investigated how passive joint manipulation, reaching behavior, and deep brain stimulation (DBS) modulate local field potential (LFP) activity in the subthalamic nucleus (STN) and globus pallidus (GP). Approach. Five non-human primates were implanted unilaterally with one or more DBS leads. LFPs were collected in montage recordings during resting state conditions and during motor tasks that facilitate the expression of parkinsonian motor signs. These recordings were made in the naïve state in one subject, in the parkinsonian state in two subjects, and in both naïve and parkinsonian states in two subjects. Main results. LFPs measured at rest were consistent over time for a given recording location and parkinsonian state in a given subject; however, LFPs were highly variable between subjects, between and within recording locations, and across parkinsonian states. LFPs in both naïve and parkinsonian states across all recorded nuclei contained a spectral peak in the beta band (10-30 Hz). Moreover, the spectral content of recorded LFPs was modulated by passive and active movement of the subjects’ limbs. LFPs recorded during a cued-reaching task displayed task-related beta desynchronization in STN and GP. The bidirectional capabilities of the Activa® PC + S also allowed for recording LFPs while delivering DBS. The therapeutic effect of STN DBS on parkinsonian rigidity outlasted stimulation for 30-60 s, but there was no correlation with beta band power. Significance. This study emphasizes (1) the variability in spontaneous LFPs amongst subjects and (2) the value of using the Activa® PC + S system to record neural data in the context of behavioral tasks that allow one to evaluate a subject’s symptomatology.

Formation of thermal coagulum on multielectrode catheters during phased radiofrequency energy ablation of persistent atrial fibrillation.

PubMed

Debruyne, Philippe; Rossenbacker, Tom; Vankelecom, Bart; Charlier, Filip; Roosen, John; Ector, Bavo; Janssens, Luc

2014-02-01

Radiofrequency ablation (RFA) can unfavorably cause coagulum on the ablation electrode. The aim of this study was to assess this phenomenon on three different multielectrode catheters used to treat persistent atrial fibrillation with duty-cycled RFA. Twenty-six consecutive patients have been treated with the pulmonary vein ablation catheter (PVAC) and the multiarray ablation catheter (MAAC). In 13 patients, additional ablation with the multiarray septal catheter (MASC) has been performed. The multichannel RF generator GENius™ (Medtronic Inc., Minneapolis, MN, USA) independently delivered energy in a bipolar and unipolar mode (ratio of 4/1, 2/1, or 1/1) to any of the electrodes. Versions 14.2, 14.3, and 14.4 of the generator were used. Coagulum presence was determined postablation by careful visual inspection of the catheter electrodes. No coagulum formation was visualized on the PVACs. Coagulum formation was visualized in 59% of the electrodes of the MAACs using a 2/1 mode and the 14.2 software version versus 69% using the 14.4 version and a 2/1 mode (P = 0.7) versus 14% of the electrodes applying a 1/1 ratio and the 14.4 software version (P < 0.001). Duty-cycled RFA in 2/1 bipolar/unipolar ratio generates a substantial frequency of coagulum formation on the multielectrode catheters MAAC and MASC. The use of the 14.4 version of the software to drive the RF generator and the use of energy in the default 1/1 bipolar/unipolar ratio could significantly reduce the frequency of coagulum formation, but so far, could not completely overcome it. The PVAC did not form coagulum, regardless of generator version or energy ratio used. ©2013, The Authors. Journal compilation ©2013 Wiley Periodicals, Inc.

Impact of operator experience and training strategy on procedural outcomes with leadless pacing: Insights from the Micra Transcatheter Pacing Study.

PubMed

El-Chami, Mikhael; Kowal, Robert C; Soejima, Kyoko; Ritter, Philippe; Duray, Gabor Z; Neuzil, Petr; Mont, Lluis; Kypta, Alexander; Sagi, Venkata; Hudnall, John Harrison; Stromberg, Kurt; Reynolds, Dwight

2017-07-01

Leadless pacemaker systems have been designed to avoid the need for a pocket and transvenous lead. However, delivery of this therapy requires a new catheter-based procedure. This study evaluates the role of operator experience and different training strategies on procedural outcomes. A total of 726 patients underwent implant attempt with the Micra transcatheter pacing system (TPS; Medtronic, Minneapolis, MN, USA) by 94 operators trained in a teaching laboratory using a simulator, cadaver, and large animal models (lab training) or locally at the hospital with simulator/demo model and proctorship (hospital training). Procedure success, procedure duration, fluoroscopy time, and safety outcomes were compared between training methods and experience (implant case number). The Micra TPS procedure was successful in 99.2% of attempts and did not differ between the 55 operators trained in the lab setting and the 39 operators trained locally at the hospital (P = 0.189). Implant case number was also not a determinant of procedural success (P = 0.456). Each operator performed between one and 55 procedures. Procedure time and fluoroscopy duration decreased by 2.0% (P = 0.002) and 3.2% (P < 0.001) compared to the previous case. Major complication rate and pericardial effusion rate were not associated with case number (P = 0.755 and P = 0.620, respectively). There were no differences in the safety outcomes by training method. Among a large group of operators, implantation success was high regardless of experience. While procedure duration and fluoroscopy times decreased with implant number, complications were low and not associated with case number. Procedure and safety outcomes were similar between distinct training methodologies. © 2017 Wiley Periodicals, Inc.

Improved spatial targeting with directionally segmented deep brain stimulation leads for treating essential tremor

NASA Astrophysics Data System (ADS)

Keane, Maureen; Deyo, Steve; Abosch, Aviva; Bajwa, Jawad A.; Johnson, Matthew D.

2012-08-01

Deep brain stimulation (DBS) in the ventral intermediate nucleus of thalamus (Vim) is known to exert a therapeutic effect on postural and kinetic tremor in patients with essential tremor (ET). For DBS leads implanted near the caudal border of Vim, however, there is an increased likelihood that one will also induce paresthesia side-effects by stimulating neurons within the sensory pathway of the ventral caudal (Vc) nucleus of thalamus. The aim of this computational study was to (1) investigate the neuronal pathways modulated by therapeutic, sub-therapeutic and paresthesia-inducing DBS settings in three patients with ET and (2) determine how much better an outcome could have been achieved had these patients been implanted with a DBS lead containing directionally segmented electrodes (dDBS). Multi-compartment neuron models of the thalamocortical, cerebellothalamic and medial lemniscal pathways were first simulated in the context of patient-specific anatomies, lead placements and programming parameters from three ET patients who had been implanted with Medtronic 3389 DBS leads. The models showed that in these patients, complete suppression of tremor was associated most closely with activating an average of 62% of the cerebellothalamic afferent input into Vim (n = 10), while persistent paresthesias were associated with activating 35% of the medial lemniscal tract input into Vc thalamus (n = 12). The dDBS lead design demonstrated superior targeting of the cerebello-thalamo-cortical pathway, especially in cases of misaligned DBS leads. Given the close proximity of Vim to Vc thalamus, the models suggest that dDBS will enable clinicians to more effectively sculpt current through and around thalamus in order to achieve a more consistent therapeutic effect without inducing side-effects.

Leading by feel.

PubMed

2004-01-01

Like it or not, leaders need to manage the mood of their organizations. The most gifted leaders accomplish that by using a mysterious blend of psychological abilities known as emotional intelligence. They are self-aware and empathetic. They can read and regulate their own emotions while intuitively grasping how others feel and gauging their organization's emotional state. But where does emotional intelligence come from, and how do leaders learn to use it? In this article, 18 leaders and scholars (including business executives, leadership researchers, psychologists, an autism expert, and a symphony conductor) explore the nature and management of emotional intelligence--its sources, uses, and abuses. Their responses varied, but some common themes emerged: the importance of consciously--and conscientiously--honing one's skills, the double-edged nature of self-awareness, and the danger of letting any one emotional intelligence skill dominate. Among their observations: Psychology professor John Mayer, who co-developed the concept of emotional intelligence, warns managers not to be confused by popular definitions of the term, which suggest that if you have a certain set of personality traits then you automatically possess emotional intelligence. Neuropsychologist Elkhonon Goldberg agrees with professors Daniel Goleman and Robert Goffee that emotional intelligence can be learned--but only by people who already show an aptitude for it. Cult expert Janja Lalich points out that leaders can use their emotional intelligence skills for ill in the same way they can for good. "Sometimes the only difference is [the leader's] intent," she says. And business leaders Carol Bartz, William George, Sidney Harman, and Andrea jung (of Autodesk, Medtronic, Harman International, and Avon respectively) describe situations in which emotional intelligence traits such as self-awareness and empathy have helped them and their companies perform at a higher level.

Use of Continuous Glucose Monitoring as an Outcome Measure in Clinical Trials

PubMed Central

Calhoun, Peter; Kollman, Craig

2012-01-01

Abstract Objective Although developed to be a management tool for individuals with diabetes, continuous glucose monitoring (CGM) also has potential value for the assessment of outcomes in clinical studies. We evaluated using CGM as such an outcome measure. Research Design and Methods Data were analyzed from six previously completed inpatient studies in which both CGM (Freestyle Navigator™ [Abbott Diabetes Care, Alameda, CA] or Guardian® [Medtronic, Northridge, CA]) and reference glucose measurements were available. The analyses included 97 days of data from 93 participants with type 1 diabetes (age range, 5–57 years; mean, 18±12 years). Results Mean glucose levels per day were similar for the CGM and reference measurements (median, 148 mg/dL vs. 143 mg/dL, respectively; P=0.92), and the correlation of the two was high (r=0.89). Similarly, most glycemia metrics showed no significant differences comparing CGM and reference values, except that the nadir glucose tended to be slightly lower and peak glucose slightly higher with reference measurements than CGM measurements (respective median, 59 mg/dL vs. 66 mg/dL [P=0.05] and 262 mg/dL vs. 257 mg/dL [P=0.003]) and glucose variability as measured with the coefficient of variation was slightly lower with CGM than reference measurements (respective median, 31% vs. 35%; P<0.001). Conclusions A reasonably high degree of concordance exists when comparing outcomes based on CGM measurements with outcomes based on reference blood glucose measurements. CGM inaccuracy and underestimation of the extremes of hyperglycemia and hypoglycemia can be accounted for in a clinical trial's study design. Thus, in appropriate settings, CGM can be a very meaningful and feasible outcome measure for clinical trials. PMID:23013201

Generator exchange is associated with an increased rate of Sprint Fidelis lead failure.

PubMed

Lovelock, Joshua D; Patel, Ayesha; Mengistu, Andenet; Hoskins, Michael; El-Chami, Mikhael; Lloyd, Michael S; Leon, Angel; DeLurgio, David; Langberg, Jonathan J

2012-10-01

The Medtronic Sprint Fidelis defibrillator lead is at an increased risk for failure and was recalled in October 2007. Approximately 268,000 leads were implanted, and more than 100,000 patients still have active Fidelis leads. A number of studies have examined the rate and clinical predictors of lead failure, but none has addressed the effect of an implantable cardioverter-defibrillator generator exchange on subsequent lead failure. Although the manufacturer asserts that "Sprint Fidelis performance after device change-out is similar to lead performance without device change-out," published data are lacking. To assess the effect of implantable cardioverter-defibrillator generator exchange on the rate of Fidelis lead failure. A chart review was conducted in patients who underwent implantation of a Fidelis lead. Patients with a functioning Fidelis lead at generator exchange were compared with controls with leads implanted for a comparable amount of time not undergoing ICD replacement. A total of 1366 patients received a Fidelis lead prior to the recall, of which 479 were still actively followed. Seventy-two patients with a functioning lead underwent generator exchange without lead replacement. Following generator replacement, 15 leads failed. Sixty percent of the Fidelis leads failed within 3 months. Generator exchange increased the rate of lead failure compared with matched controls (20.8% vs 2.54%; P < .001). Generator exchange is associated with a higher than expected rate of Fidelis lead failure, often within 3 months. The risk-benefit ratio of Fidelis lead replacement at the time of generator exchange may be greater than appreciated. Copyright © 2012 Heart Rhythm Society. Published by Elsevier Inc. All rights reserved.

Percutaneous renal sympathetic nerve ablation for loin pain haematuria syndrome.

PubMed

Gambaro, Giovanni; Fulignati, Pierluigi; Spinelli, Alessio; Rovella, Valentina; Di Daniele, Nicola

2013-09-01

Loin pain haematuria syndrome (LPHS) is a severe renal pain condition of uncertain origin and often resistant to treatment. Nephrectomy and renal autotrasplantation have occasionally been performed in very severe cases. Its pathogenesis is controversial. A 40-year-old hypertensive lady was diagnosed with LPHS after repeated diagnostic imaging procedures had ruled out any renal, abdominal or spinal conditions to justify pain. Notwithstanding treatment with three drugs, she had frequent hypertensive crises during which the loin pain was dramatically exacerbated. Vascular causes of the pain and hypertension were investigated and excluded. Her renal function was normal. The patient was referred to a multidisciplinary pain clinic, but had no significant improvement in her pain symptoms despite the use of non-steroidal anti-inflammatory drugs, adjuvant antidepressants and opioid-like agents. The pain and the discomfort were so severe that her quality of life was very poor, and her social and professional activities were compromised. Nephrectomy and renal autotransplantation have occasionally been performed in these cases. Since visceral pain signals flow through afferent sympathetic fibres, we felt that percutaneous catheter-based radiofrequency ablation of the renal sympathetic nerve fibres (recently introduced for the treatment of drug-resistant hypertension) could be valuable for pain relief. We treated the patient with radiofrequency ablation (Medtronic Symplicity Catheter) applied only to the right renal artery. After a 6-month follow-up, the patient is pain free and normotensive with all drugs withdrawn. She has experienced no hypertensive crises in the meantime. This observation suggests that percutaneous sympathetic denervation could prove to be an effective mini-invasive strategy for the treatment of chronic renal pain, and LPHS in particular.

Creating new growth platforms.

PubMed

Laurie, Donald L; Doz, Yves L; Sheer, Claude P

2006-05-01

Sooner or later, most companies can't attain the growth rates expected by their boards and CEOs and demanded by investors. To some extent, such businesses are victims of their own successes. Many were able to sustain high growth rates for a long time because they were in high-growth industries. But once those industries slowed down, the businesses could no longer deliver the performance that investors had come to take for granted. Often, companies have resorted to acquisition, though this strategy has a discouraging track record. Over time, 65% of acquisitions destroy more value than they create. So where does real growth come from? For the past 12 years, the authors have been researching and advising companies on this issue. With the support of researchers at Harvard Business School and Insead, they instituted a project titled "The CEO Agenda and Growth". They identified and approached 24 companies that had achieved significant organic growth and interviewed their CEOs, chief strategists, heads of R&D, CFOs, and top-line managers. They asked, "Where does your growth come from?" and found a consistent pattern in the answers. All the businesses grew by creating new growth platforms (NGPs) on which they could build families of products and services and extend their capabilities into multiple new domains. Identifying NGP opportunities calls for executives to challenge conventional wisdom. In all the companies studied, top management believed that NGP innovation differed significantly from traditional product or service innovation. They had independent, senior-level units with a standing responsibility to create NGPs, and their CEOs spent as much as 50% of their time working with these units. The payoff has been spectacular and lasting. For example, from 1985 to 2004, the medical devices company Medtronic grew revenues at 18% per year, earnings at 20%, and market capitalization at 30%.

Effects of renal sympathetic denervation on cardiac sympathetic activity and function in patients with therapy resistant hypertension.

PubMed

van Brussel, Peter M; Eeftinck Schattenkerk, Daan W; Dobrowolski, Linn C; de Winter, Robbert J; Reekers, Jim A; Verberne, Hein J; Vogt, Liffert; van den Born, Bert-Jan H

2016-01-01

Renal sympathetic denervation (RSD) is currently being investigated in multiple studies of sympathetically driven cardiovascular diseases such as heart failure and arrhythmias. Our aim was to assess systemic and cardiac sympatholytic effects of RSD by the measurement of cardiac sympathetic activity and cardiovascular parameters. A total of 21 consecutive patients with refractory hypertension (daytime ambulatory blood pressure (BP)≥150/100 mmHg despite the use of 3 or more antihypertensive drugs), no evidence for secondary hypertension and normal renovascular anatomy were included. RSD was performed with the Medtronic Symplicity renal denervation catheter with an average of 4.2 (range 3-6) ablations per renal artery. To assess cardiac sympathetic activity, 123I-mIBG cardiac scintigraphy was performed before and 6 weeks after. In addition, the effect of RSD on peripheral BP and cardiac hemodynamics were assessed non-invasively. 123I-mIBG uptake before and after RSD was 1.7±0.4% vs. 1.7±0.5% at 15 min. and 1.4±0.4% vs. 1.5±0.5% after 4 h. As a consequence, washout rate was similar before (33.7±11.7%) and after RSD (30.1±12.6%, p=0.27). In line with earlier RSD studies, a significant drop in systolic office BP (-12.2 mmHg, p=0.04) was detected, whereas the decrease in ambulatory BP was not significant. No changes were seen in heart rate, stroke volume or left ventricular contractility, both in supine position and after standing. In concert with previous reports, RSD leads to a significant drop in office BP. However, a reduction in sympathetic activity could not be demonstrated on a cardiac level. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

Determinants of image quality of rotational angiography for on-line assessment of frame geometry after transcatheter aortic valve implantation.

PubMed

Rodríguez-Olivares, Ramón; El Faquir, Nahid; Rahhab, Zouhair; Maugenest, Anne-Marie; Van Mieghem, Nicolas M; Schultz, Carl; Lauritsch, Guenter; de Jaegere, Peter P T

2016-07-01

To study the determinants of image quality of rotational angiography using dedicated research prototype software for motion compensation without rapid ventricular pacing after the implantation of four commercially available catheter-based valves. Prospective observational study including 179 consecutive patients who underwent transcatheter aortic valve implantation (TAVI) with either the Medtronic CoreValve (MCS), Edward-SAPIEN Valve (ESV), Boston Sadra Lotus (BSL) or Saint-Jude Portico Valve (SJP) in whom rotational angiography (R-angio) with motion compensation 3D image reconstruction was performed. Image quality was evaluated from grade 1 (excellent image quality) to grade 5 (strongly degraded). Distinction was made between good (grades 1, 2) and poor image quality (grades 3-5). Clinical (gender, body mass index, Agatston score, heart rate and rhythm, artifacts), procedural (valve type) and technical variables (isocentricity) were related with the image quality assessment. Image quality was good in 128 (72 %) and poor in 51 (28 %) patients. By univariable analysis only valve type (BSL) and the presence of an artefact negatively affected image quality. By multivariate analysis (in which BMI was forced into the model) BSL valve (Odds 3.5, 95 % CI [1.3-9.6], p = 0.02), presence of an artifact (Odds 2.5, 95 % CI [1.2-5.4], p = 0.02) and BMI (Odds 1.1, 95 % CI [1.0-1.2], p = 0.04) were independent predictors of poor image quality. Rotational angiography with motion compensation 3D image reconstruction using a dedicated research prototype software offers good image quality for the evaluation of frame geometry after TAVI in the majority of patients. Valve type, presence of artifacts and higher BMI negatively affect image quality.

Vascular Entrapment of Both the Sciatic and Pudendal Nerves Causing Persistent Sciatica and Pudendal Neuralgia.

PubMed

Kale, Ahmet; Basol, Gulfem; Usta, Taner; Cam, Isa

2018-04-24

To demonstrate the laparoscopic approach to malformed branches of the vessels entrapping the nerves of the sacral plexus. A step-by-step explanation of the surgery using video (educative video) (Canadian Task force classification II). The university's Ethics Committee ruled that approval was not required for this video. Kocaeli Derince Education and Research Hospital, Kocaeli, Turkey. A 26-year-old patient who had failed medical therapy and presented with complaints of numbness and burning pain on the right side of her vagina and pain radiating to her lower limbs for a period of approximately 36 months. The peritoneum was incised along the external iliac vessels, and these vessels were separated from the iliopsoas muscle on the right side of the pelvis. The laparoscopic decompression of intrapelvic vascular entrapment was performed at 3 sites: the lumbosacral trunk, sciatic nerve, and pudendal nerve. The aberrant dilated veins were gently dissected from nerves, and then coagulated and cut with the LigaSure sealing device (Medtronic, Minneapolis, Minn). The operation was completed successfully with no complications, and the patient was discharged from the hospital 24 hours after the operation. At a 6-month follow-up, she reported complete resolution of dyspareunia and sciatica (visual analog scale score 1 of 10). A less well-known cause of chronic pelvic pain is compression of the sacral plexus by dilated or malformed branches of the internal iliac vessels. Laparoscopic management of vascular entrapment of the sacral plexus has been described by Possover et al [1,2] and Lemos et al [3]. This procedure appears to be feasible and effective, but requires significant experience and familiarity with laparoscopy techniques and pelvic nerve anatomy. Copyright © 2018 American Association of Gynecologic Laparoscopists. Published by Elsevier Inc. All rights reserved.

The changes of the frequency specific impedance of the human body due to the resonance in the kHz range in cancer diagnostics

NASA Astrophysics Data System (ADS)

Michalak, K. P.; Nawrocka-Bogusz, H.

2011-12-01

The frequency-specific absorption of kHz signals has been postulated for different tissues, trace elements, vitamins, toxins, pathogens, allergens etc. for low-power (μV) signals. An increase in the impedance of the human body is observed only up to the given power of the applied signal. The highest amplification of the given signal being damped by the body makes it possible to determine the intensity of the given process in the body (e.g. amount of the toxin, trace element, intensity of the allergy) being connected with a given frequency spectrum of the signal. The mechanism of frequency-specific absorption can be explained by means of the Quantum Field Theory being applied to the structure of the water. Substantially high coincidence between the frequencies of the rotation of free quasi-excited electrons in coherent domains of water and the frequencies being used in the MORA diagnostics (Med-Tronic GmbH, EN ISO 13485, EN ISO 9001) can be observed. These frequencies are located in the proximity of f = 7kHz · i (i = 1,3,5,7,...). This fact suggests that the coherent domains with the admixtures of the given substances create structure-specific coherent domains that possess frequency-specific absorption spectra. The diagnostic tool called "MORA System diagnosis" was used to investigate 102 patients with different types and stages of cancer. Many signals were observed to be absorbed by many cancer patients, e.g.: 'Cellular defense system', 'Degeneration tendencies', Manganese, Magnesium, Zinc, Selenium, Vitamin E, Glutamine, Glutathione, Cysteine, Candida albicans, Mycosis. The results confirm the role of oxidative stress, immunological system deficiency and mitochondria malfunction in the development of cancer.

Randomized Trial of Infusion Set Function: Steel Versus Teflon

PubMed Central

Patel, Parul J.; Benasi, Kari; Ferrari, Gina; Evans, Mark G.; Shanmugham, Satya; Wilson, Darrell M.

2014-01-01

Abstract Background: This study compared infusion set function for up to 1 week using either a Teflon® (Dupont™, Wilmington, DE) catheter or a steel catheter for insulin pump therapy in type 1 diabetes mellitus. Subjects and Methods: Twenty subjects participating in a randomized, open-labeled, crossover study were asked to wear two Quick-Set® and two Sure-T® infusion sets (both from Medtronic Minimed, Northridge, CA) until the infusion set failed or was worn for 1 week. All subjects wore a MiniMed continuous glucose monitoring system for the duration of the study. Results: One subject withdrew from the study. There were 38 weeks of Sure-T wear and 39 weeks of Quick-Set wear with no difference in the survival curves of the infusion sets. There was, however, a 15% initial failure rate with the Teflon infusion set. After 7 days, both types of infusion sets had a 64% failure rate. Overall, 30% failed because of hyperglycemia and a failed correction dose, 13% were removed for pain, 10% were pulled out by accident, 10% had erythema and/or induration of>10 mm, 5% fell out because of loss of adhesion, and 4% were removed for infection. The main predictor of length of wear was the individual subject. There was no increase in hyperglycemia or daily insulin requirements when an infusion set was successfully used for 7 days (n=25 of 77 weeks). Conclusions: We found no difference between steel and Teflon infusion sets in their function over 7 days, although 15% of Teflon sets failed because of kinking on insertion. The strongest predictor of prolonged 7-day infusion set function was the individual subject, not the type of infusion set. PMID:24090124

Battery longevity from cardiac resynchronization therapy defibrillators: differences between manufacturers and discrepancies with published product performance reports.

PubMed

Alam, Mian Bilal; Munir, Muhammad Bilal; Rattan, Rohit; Adelstein, Evan; Jain, Sandeep; Saba, Samir

2017-03-01

Cardiac resynchronization therapy (CRT) is an important treatment for heart failure that requires constant ventricular pacing, placing a high energy burden on CRT defibrillators (CRT-D). Longer battery life reduces the need for device changes and associated complications, thereby affecting patient outcomes and cost of care. We therefore investigated the time to battery depletion of CRT-D from different manufacturers and compared these results with manufacturers' published product performance reports (PPRs). All CRT-D recipients at our institution between January 2008 and December 2010 were included in this study cohort. The patients were followed up to the endpoint of battery depletion and were otherwise censored at the time of death, last follow-up, or device removal for any reason other than battery depletion. A total of 621 patients [173 Boston Scientific (BSC), 391 Medtronic (MDT), and 57 St. Jude Medical (SJM)] were followed up for a median of 3.7 (IQR 1.6-5.0) years, during which time 253 (41%) devices were replaced for battery depletion. Compared with MDT devices, battery depletion was 85 and 54% less likely to happen with BSC and SJM devices, respectively (P < 0.001 for pairwise comparisons). Product performance reports from all manufacturers significantly overestimated battery longevity by more than 20% 6 years after device implantation. Large differences in CRT-D battery longevity exist between manufacturers. Industry-published PPRs significantly overestimate device longevity. These data have important implications to patients, healthcare professionals, hospitals, and third-party payers. Published on behalf of the European Society of Cardiology. All rights reserved. © The Author 2016. For permissions please email: journals.permissions@oup.com.

Evaluation of factors affecting CGMS calibration.

PubMed

Buckingham, Bruce A; Kollman, Craig; Beck, Roy; Kalajian, Andrea; Fiallo-Scharer, Rosanna; Tansey, Michael J; Fox, Larry A; Wilson, Darrell M; Weinzimer, Stuart A; Ruedy, Katrina J; Tamborlane, William V

2006-06-01

The optimal number/timing of calibrations entered into the CGMS (Medtronic MiniMed, Northridge, CA) continuous glucose monitoring system have not been previously described. Fifty subjects with Type 1 diabetes mellitus (10-18 years old) were hospitalized in a clinical research center for approximately 24 h on two separate days. CGMS and OneTouch Ultra meter (LifeScan, Milpitas, CA) data were obtained. The CGMS was retrospectively recalibrated using the Ultra data varying the number and timing of calibrations. Resulting CGMS values were compared against laboratory reference values. There was a modest improvement in accuracy with increasing number of calibrations. The median relative absolute deviation (RAD) was 14%, 15%, 13%, and 13% when using three, four, five, and seven calibration values, respectively (P < 0.001). Corresponding percentages of CGMS-reference pairs meeting the International Organisation for Standardisation criteria were 66%, 67%, 71%, and 72% (P < 0.001). Nighttime accuracy improved when daytime calibrations (pre-lunch and pre-dinner) were removed leaving only two calibrations at 9 p.m. and 6 a.m. (median difference, -2 vs. -9 mg/dL, P < 0.001; median RAD, 12% vs. 15%, P = 0.001). Accuracy was better on visits where the average absolute rate of glucose change at the times of calibration was lower. On visits with average absolute rates <0.5, 0.5 to <1.0, 1.0 to <1.5, and >or=1.5 mg/dL/min, median RAD values were 13% versus 14% versus 17% versus 19%, respectively (P = 0.05). Although accuracy is slightly improved with more calibrations, the timing of the calibrations appears more important. Modifying the algorithm to put less weight on daytime calibrations for nighttime values and calibrating during times of relative glucose stability may have greater impact on accuracy.

Evaluation of Factors Affecting CGMS Calibration

PubMed Central

2006-01-01

Background The optimal number/timing of calibrations entered into the Continuous Glucose Monitoring System (“CGMS”; Medtronic MiniMed, Northridge, CA) have not been previously described. Methods Fifty subjects with T1DM (10–18y) were hospitalized in a clinical research center for ~24h on two separate days. CGMS and OneTouch® Ultra® Meter (“Ultra”; LifeScan, Milpitas, CA) data were obtained. The CGMS was retrospectively recalibrated using the Ultra data varying the number and timing of calibrations. Resulting CGMS values were compared against laboratory reference values. Results There was a modest improvement in accuracy with increasing number of calibrations. The median relative absolute deviation (RAD) was 14%, 15%, 13% and 13% when using 3, 4, 5 and 7 calibration values, respectively (p<0.001). Corresponding percentages of CGMS-reference pairs meeting the ISO criteria were 66%, 67%, 71% and 72% (p<0.001). Nighttime accuracy improved when daytime calibrations (pre-lunch and pre-dinner) were removed leaving only two calibrations at 9p.m. and 6a.m. (median difference: −2 vs. −9mg/dL, p<0.001; median RAD: 12% vs. 15%, p=0.001). Accuracy was better on visits where the average absolute rate of glucose change at the times of calibration was lower. On visits with average absolute rates <0.5, 0.5-<1.0, 1.0-<1.5 and ≥1.5mg/dL/min, median RAD values were 13% vs. 14% vs. 17% vs. 19%, respectively (p=0.05). Conclusions Although accuracy is slightly improved with more calibrations, the timing of the calibrations appears more important. Modifying the algorithm to put less weight on daytime calibrations for nighttime values and calibrating during times of relative glucose stability may have greater impact on accuracy. PMID:16800753

Every slow-wave impulse is associated with motor activity of the human stomach.

PubMed

Hocke, Michael; Schöne, Ulrike; Richert, Hendryk; Görnert, Peter; Keller, Jutta; Layer, Peter; Stallmach, Andreas

2009-04-01

Using a newly developed high-resolution three-dimensional magnetic detector system (3D-MAGMA), we observed periodical movements of a small magnetic marker in the human stomach at the typical gastric slow-wave frequency, that is 3 min(-1). Thus we hypothesized that each gastric slow wave induces a motor response that is not strong enough to be detected by conventional methods. Electrogastrographies (EGG, Medtronic, Minneapolis, MN) for measurement of gastric slow waves and 3D-MAGMA (Innovent, Jena, Germany) measurements were simultaneously performed in 21 healthy volunteers (10 men, 40.4+/-13.6 yr; 11 women, 35.8+/-11.6 yr). The 3D-MAGMA system contains 27 highly sensitive magnetic field sensors that are able to locate a magnetic pill inside a human body with an accuracy of +/-5 mm or less in position and +/-2 degrees in orientation at a frequency of 50 Hz. Gastric transit time of the magnetic marker ranged from 19 to 154 min. The mean dominant EGG frequency while the marker was in the stomach was 2.87+/-0.15 cpm. The mean dominant 3D-MAGMA frequency during this interval was nearly identical; that is, 2.85+/-0.15 movements per minute. We observed a strong linear correlation between individual dominant EGG and 3D-MAGMA frequency (R=0.66, P=0.0011). Our findings suggest that each gastric slow wave induces a minute contraction that is too small to be detected by conventional motility investigations but can be recorded by the 3D-MAGMA system. The present slow-wave theory that assumes that the slow wave is a pure electrical signal should be reconsidered.

The Effect of Saline Coolant on Temperature Levels during Decortication with a Midas Rex: An in Vitro Model Using Sheep Cervical Vertebrae.

PubMed

Livingston, Asher; Wang, Tian; Christou, Chris; Pelletier, Matthew H; Walsh, William R

2015-01-01

Decortication of bone with a high-speed burr in the absence of coolant may lead to local thermal necrosis and decreased healing ability, which may negatively impact clinical outcome. Little data are available on the impact of applying a coolant during the burring process. This study aims to establish an in vitro model to quantitatively assess peak temperatures during endplate preparation with a high-speed burr. Six sheep cervical vertebrae were dissected and mounted. Both end plates were used to give a total of 12 sites. Two thermocouples were inserted into each vertebra, 2 mm below the end plate surface and a thermal camera set up to measure surface temperature. A 3 mm high-pneumatic speed burr (Midas Rex, Medtronic, Fort Worth, TX, USA) was used to decorticate the bone in a side to side sweeping pattern, using a matchstick burr (M-8/9MH30) with light pressure. This procedure was repeated while dripping saline onto the burr and bone. Data were compared between groups using a Student's t-test. Application of coolant at the bone-burr interface during decortication resulted in a significant decrease in final temperature. Without coolant, maximum temperatures 2 mm from the surface were not sufficient to cause thermal osteonecrosis, although peak surface temperatures would cause local damage. The use of a high-speed burr provides a quick and an effective method of vertebral end plate preparation. Thermal damage to the bone can be minimized through the use of light pressure and saline coolant. This has implications for any bone preparation performed with a high-speed burr.

Development and validation of a novel algorithm based on the ECG magnet response for rapid identification of any unknown pacemaker.

PubMed

Squara, Fabien; Chik, William W; Benhayon, Daniel; Maeda, Shingo; Latcu, Decebal Gabriel; Lacaze-Gadonneix, Jonathan; Tibi, Thierry; Thomas, Olivier; Cooper, Joshua M; Duthoit, Guillaume

2014-08-01

Pacemaker (PM) interrogation requires correct manufacturer identification. However, an unidentified PM is a frequent occurrence, requiring time-consuming steps to identify the device. The purpose of this study was to develop and validate a novel algorithm for PM manufacturer identification, using the ECG response to magnet application. Data on the magnet responses of all recent PM models (≤15 years) from the 5 major manufacturers were collected. An algorithm based on the ECG response to magnet application to identify the PM manufacturer was subsequently developed. Patients undergoing ECG during magnet application in various clinical situations were prospectively recruited in 7 centers. The algorithm was applied in the analysis of every ECG by a cardiologist blinded to PM information. A second blinded cardiologist analyzed a sample of randomly selected ECGs in order to assess the reproducibility of the results. A total of 250 ECGs were analyzed during magnet application. The algorithm led to the correct single manufacturer choice in 242 ECGs (96.8%), whereas 7 (2.8%) could only be narrowed to either 1 of 2 manufacturer possibilities. Only 2 (0.4%) incorrect manufacturer identifications occurred. The algorithm identified Medtronic and Sorin Group PMs with 100% sensitivity and specificity, Biotronik PMs with 100% sensitivity and 99.5% specificity, and St. Jude and Boston Scientific PMs with 92% sensitivity and 100% specificity. The results were reproducible between the 2 blinded cardiologists with 92% concordant findings. Unknown PM manufacturers can be accurately identified by analyzing the ECG magnet response using this newly developed algorithm. Copyright © 2014 Heart Rhythm Society. Published by Elsevier Inc. All rights reserved.

Remote monitoring of patients with cardiac implantable electronic devices: a Southeast Asian, single-centre pilot study.

PubMed

Lim, Paul Chun Yih; Lee, Audry Shan Yin; Chua, Kelvin Chi Ming; Lim, Eric Tien Siang; Chong, Daniel Thuan Tee; Tan, Boon Yew; Ho, Kah Leng; Teo, Wee Siong; Ching, Chi Keong

2016-07-01

Remote monitoring of cardiac implantable electronic devices (CIED) has been shown to improve patient safety and reduce in-office visits. We report our experience with remote monitoring via the Medtronic CareLink(®) network. Patients were followed up for six months with scheduled monthly remote monitoring transmissions in addition to routine in-office checks. The efficacy of remote monitoring was evaluated by recording compliance to transmissions, number of device alerts requiring intervention and time from transmission to review. Questionnaires were administered to evaluate the experiences of patients, physicians and medical technicians. A total of 57 patients were enrolled; 16 (28.1%) had permanent pacemakers, 34 (59.6%) had implantable cardioverter defibrillators and 7 (12.3%) had cardiac resynchronisation therapy defibrillators. Overall, of 334 remote transmissions scheduled, 73.7% were on time, 14.5% were overdue and 11.8% were missed. 84.6% of wireless transmissions were on time, compared to 53.8% of non-wireless transmissions. Among all transmissions, 4.4% contained alerts for which physicians were informed and only 1.8% required intervention. 98.6% of remote transmissions were reviewed by the second working day. 73.2% of patients preferred remote monitoring. Physicians agreed that remote transmissions provided information equivalent to in-office checks 97.1% of the time. 77.8% of medical technicians felt that remote monitoring would help the hospital improve patient management. No adverse events were reported. Remote monitoring of CIED is safe and feasible. It has possible benefits to patient safety through earlier detection of arrhythmias or device malfunction, permitting earlier intervention. Wireless remote monitoring, in particular, may improve compliance to device monitoring. Patients may prefer remote monitoring due to possible improvements in quality of life. Copyright: © Singapore Medical Association.

Results of remote follow-up and monitoring in young patients with cardiac implantable electronic devices.

PubMed

Silvetti, Massimo S; Saputo, Fabio A; Palmieri, Rosalinda; Placidi, Silvia; Santucci, Lorenzo; Di Mambro, Corrado; Righi, Daniela; Drago, Fabrizio

2016-01-01

Remote monitoring is increasingly used in the follow-up of patients with cardiac implantable electronic devices. Data on paediatric populations are still lacking. The aim of our study was to follow-up young patients both in-hospital and remotely to enhance device surveillance. This is an observational registry collecting data on consecutive patients followed-up with the CareLink system. Inclusion criteria were a Medtronic device implanted and patient's willingness to receive CareLink. Patients were stratified according to age and presence of congenital/structural heart defects (CHD). A total of 221 patients with a device - 200 pacemakers, 19 implantable cardioverter defibrillators, and two loop recorders--were enrolled (median age of 17 years, range 1-40); 58% of patients were younger than 18 years of age and 73% had CHD. During a follow-up of 12 months (range 4-18), 1361 transmissions (8.9% unscheduled) were reviewed by technicians. Time for review was 6 ± 2 minutes (mean ± standard deviation). Missed transmissions were 10.1%. Events were documented in 45% of transmissions, with 2.7% yellow alerts and 0.6% red alerts sent by wireless devices. No significant differences were found in transmission results according to age or presence of CHD. Physicians reviewed 6.3% of transmissions, 29 patients were contacted by phone, and 12 patients underwent unscheduled in-hospital visits. The event recognition with remote monitoring occurred 76 days (range 16-150) earlier than the next scheduled in-office follow-up. Remote follow-up/monitoring with the CareLink system is useful to enhance device surveillance in young patients. The majority of events were not clinically relevant, and the remaining led to timely management of problems.

Global, Regional, and National Burden of Rheumatic Heart Disease, 1990-2015.

PubMed

Watkins, David A; Johnson, Catherine O; Colquhoun, Samantha M; Karthikeyan, Ganesan; Beaton, Andrea; Bukhman, Gene; Forouzanfar, Mohammed H; Longenecker, Christopher T; Mayosi, Bongani M; Mensah, George A; Nascimento, Bruno R; Ribeiro, Antonio L P; Sable, Craig A; Steer, Andrew C; Naghavi, Mohsen; Mokdad, Ali H; Murray, Christopher J L; Vos, Theo; Carapetis, Jonathan R; Roth, Gregory A

2017-08-24

Rheumatic heart disease remains an important preventable cause of cardiovascular death and disability, particularly in low-income and middle-income countries. We estimated global, regional, and national trends in the prevalence of and mortality due to rheumatic heart disease as part of the 2015 Global Burden of Disease study. We systematically reviewed data on fatal and nonfatal rheumatic heart disease for the period from 1990 through 2015. Two Global Burden of Disease analytic tools, the Cause of Death Ensemble model and DisMod-MR 2.1, were used to produce estimates of mortality and prevalence, including estimates of uncertainty. We estimated that there were 319,400 (95% uncertainty interval, 297,300 to 337,300) deaths due to rheumatic heart disease in 2015. Global age-standardized mortality due to rheumatic heart disease decreased by 47.8% (95% uncertainty interval, 44.7 to 50.9) from 1990 to 2015, but large differences were observed across regions. In 2015, the highest age-standardized mortality due to and prevalence of rheumatic heart disease were observed in Oceania, South Asia, and central sub-Saharan Africa. We estimated that in 2015 there were 33.4 million (95% uncertainty interval, 29.7 million to 43.1 million) cases of rheumatic heart disease and 10.5 million (95% uncertainty interval, 9.6 million to 11.5 million) disability-adjusted life-years due to rheumatic heart disease globally. We estimated the global disease prevalence of and mortality due to rheumatic heart disease over a 25-year period. The health-related burden of rheumatic heart disease has declined worldwide, but high rates of disease persist in some of the poorest regions in the world. (Funded by the Bill and Melinda Gates Foundation and the Medtronic Foundation.).

Do CTA measurements of annular diameter, perimeter and area result in different TAVI prosthesis sizes?

PubMed

Horehledova, Barbora; Mihl, Casper; Hendriks, Babs M F; Eijsvoogel, Nienke G; Vainer, Jindrich; Veenstra, Leo F; Wildberger, Joachim E; Das, Marco

2018-06-16

Incorrect prosthesis size has direct impact on patient outcome after transcatheter aortic valve implantation (TAVI) procedure. Currently, annular diameter, area or perimeter may be used for prosthesis size selection. The aim was to evaluate whether the use different annular dimensions would result in the selection of different prosthesis sizes, when assessed in the same TAVI-candidate during the same phase of a cardiac cycle. Fifty consecutive TAVI-candidates underwent retrospectively ECG-gated computed tomography angiography (CTA). Aortic root dimensions were assessed in the 20% phase of the R-R interval. Annular short diameter, perimeter and area were used to select the prosthesis size, based on the industry recommendations for a self-expandable (Medtronic CoreValve; MCV) and balloon-expandable (Edwards Sapien XT Valve; ESV) valve. Complete agreement on selected prosthesis size amongst all three annular dimensions was observed in 62% (31/50; ESV) and 30% (15/50; MCV). Short aortic annulus measurement resulted in a smaller prosthesis size in 20% (10/50; ESV) and in 60% of cases (30/50; MCV) compared to the size suggested by both annular perimeter and area. In 18% (9/50; ESV) and 10% of cases (5/50; MCV) a larger prosthesis would have been selected based on annular perimeter compared to annular diameter and area. Prosthesis size derived from area was always in agreement with at least one other parameter in all cases. Aortic annulus area appears to be the most robust parameter for TAVI-prosthesis size selection, regardless of the specific prosthesis size. Short aortic annulus diameter may underestimate the prosthesis size, while use of annular perimeter may lead to size overestimation in some cases.

Electromagnetic interference of GSM mobile phones with the implantable deep brain stimulator, ITREL-III

PubMed Central

Kainz, Wolfgang; Alesch, François; Chan, Dulciana Dias

2003-01-01

Background The purpose was to investigate mobile phone interference with implantable deep brain stimulators by means of 10 different 900 Mega Hertz (MHz) and 10 different 1800 MHz GSM (Global System for Mobile Communications) mobile phones. Methods All tests were performed in vitro using a phantom especially developed for testing with deep brain stimulators. The phantom was filled with liquid phantom materials simulating brain and muscle tissue. All examinations were carried out inside an anechoic chamber on two implants of the same type of deep brain stimulator: ITREL-III from Medtronic Inc., USA. Results Despite a maximum transmitted peak power of mobile phones of 1 Watt (W) at 1800 MHz and 2 W at 900 MHz respectively, no influence on the ITREL-III was found. Neither the shape of the pulse form changed nor did single pulses fail. Tests with increased transmitted power using CW signals and broadband dipoles have shown that inhibition of the ITREL-III occurs at frequency dependent power levels which are below the emissions of GSM mobile phones. The ITREL-III is essentially more sensitive at 1800 MHz than at 900 MHz. Particularly the frequency range around 1500 MHz shows a very low interference threshold. Conclusion These investigations do not indicate a direct risk for ITREL-III patients using the tested GSM phones. Based on the interference levels found with CW signals, which are below the mobile phone emissions, we recommend similar precautions as for patients with cardiac pacemakers: 1. The phone should be used at the ear at the opposite side of the implant and 2. The patient should avoid carrying the phone close to the implant. PMID:12773204

Mapping and isolation of the pulmonary veins using the PVAC catheter.

PubMed

Duytschaever, Mattias; Anne, Wim; Papiashvili, Giorgi; Vandekerckhove, Yves; Tavernier, Rene

2010-02-01

We aimed to investigate the feasibility, efficacy, and safety of the pulmonary vein ablation catheter (PVAC) catheter (a novel multielectrode catheter using duty-cycled bipolar and unipolar radiofrequency energy, Medtronic, Minneapolis, MN, USA) to completely isolate the pulmonary veins (PVs). Twenty-seven patients (60 +/- 8 years) with paroxysmal atrial fibrillation (AF) underwent PV isolation with the PVAC catheter. PVAC was used for both mapping and isolation of the PVs (PVAC-guided ablation). After PVAC ablation, presence/absence of PV potentials (PVP) was verified using a conventional circular mapping catheter. In case of residual PVP on the circular catheter, PVAC ablation was continued. After PVAC-guided ablation 99 of 106 PVs (93%) and 21 of 27 patients (78%) were proven to be isolated. Failure to isolate was due to a mapping failure in four right-sided PVs and a true ablation failure in three right-sided PVs. After continued PVAC ablation, 103 of 106 PVs (97%) and 25 of 27 patients (93%) were shown to be isolated. The total procedural time from femoral vein access to complete catheter withdrawal was 176 +/- 25 minutes. The actual dwelling-time of the PVAC within the left atrium was 102 +/- 37 minutes. Esophageal T degrees rise to >38.5 degrees occurred in nine of 19 monitored patients (47%). (1) PVAC-guided ablation (i.e., mapping and ablation with a single catheter) results in isolation of all PVs in 73% of the patients. (2) An additional circular mapping catheter is required to increase complete isolation rate to 93% of the patients. (3) Given the esophageal T degrees rise in almost 50% of patients, safety precautions are needed.

Anal sphincter function as assessed by 3D high definition anorectal manometry.

PubMed

Mion, François; Garros, Aurélien; Subtil, Fabien; Damon, Henri; Roman, Sabine

2018-03-15

High resolution anorectal manometry has been developed over the past years, as well as 3D high definition manometry (HDARM). However, the clinical impact of the results obtained with these new technologies remains to be determined. We thus analyzed various HDARM parameters of anal sphincter function and tested their capacity to discriminate between patients with constipation and those with fecal incontinence. One hundred and fourteen consecutive patients underwent the same HDARM protocol (Medtronic), including 2 short duration voluntary anal contractions (5seconds) and 1 sustained (as long as possible) contraction. Various parameters evaluating the anal sphincter function were measured, based on automatic software analysis and Smartmouse™ item of the software; resting anal pressures, anal pressures and incremental pressures during voluntary squeeze and cough anal reflex. The ability of these parameters to discriminate between patients with fecal incontinence and chronic constipation was assessed using areas under the curves of ROC curves. All parameters were highly correlated. The most discriminant variable was found to be the mean anal pressure during sustained squeeze. The 3D lambda aspect of the anal sphincter during voluntary contraction was as frequently absent in both groups of patients (13% in patients with chronic constipation, versus 23% in those with fecal incontinence, P=0.18). There was a significant correlation between the fecal incontinence Wexner score and the voluntary anal contraction variables. Several parameters to assess the quality of voluntary anal contraction have been proposed. We observed with HDARM that the most discriminant parameter was the mean anal pressure during sustained squeeze. This may help to standardize and simplify HDARM protocols. Copyright © 2018 Elsevier Masson SAS. All rights reserved.

Remote monitoring of patients with cardiac implantable electronic devices: a Southeast Asian, single-centre pilot study

PubMed Central

Lim, Paul Chun Yih; Lee, Audry Shan Yin; Chua, Kelvin Chi Ming; Lim, Eric Tien Siang; Chong, Daniel Thuan Tee; Tan, Boon Yew; Ho, Kah Leng; Teo, Wee Siong; Ching, Chi Keong

2016-01-01

INTRODUCTION Remote monitoring of cardiac implantable electronic devices (CIED) has been shown to improve patient safety and reduce in-office visits. We report our experience with remote monitoring via the Medtronic CareLink® network. METHODS Patients were followed up for six months with scheduled monthly remote monitoring transmissions in addition to routine in-office checks. The efficacy of remote monitoring was evaluated by recording compliance to transmissions, number of device alerts requiring intervention and time from transmission to review. Questionnaires were administered to evaluate the experiences of patients, physicians and medical technicians. RESULTS A total of 57 patients were enrolled; 16 (28.1%) had permanent pacemakers, 34 (59.6%) had implantable cardioverter defibrillators and 7 (12.3%) had cardiac resynchronisation therapy defibrillators. Overall, of 334 remote transmissions scheduled, 73.7% were on time, 14.5% were overdue and 11.8% were missed. 84.6% of wireless transmissions were on time, compared to 53.8% of non-wireless transmissions. Among all transmissions, 4.4% contained alerts for which physicians were informed and only 1.8% required intervention. 98.6% of remote transmissions were reviewed by the second working day. 73.2% of patients preferred remote monitoring. Physicians agreed that remote transmissions provided information equivalent to in-office checks 97.1% of the time. 77.8% of medical technicians felt that remote monitoring would help the hospital improve patient management. No adverse events were reported. CONCLUSION Remote monitoring of CIED is safe and feasible. It has possible benefits to patient safety through earlier detection of arrhythmias or device malfunction, permitting earlier intervention. Wireless remote monitoring, in particular, may improve compliance to device monitoring. Patients may prefer remote monitoring due to possible improvements in quality of life. PMID:27439396

A cluster randomised trial, cost-effectiveness analysis and psychosocial evaluation of insulin pump therapy compared with multiple injections during flexible intensive insulin therapy for type 1 diabetes: the REPOSE Trial.

PubMed Central

Heller, Simon; White, David; Lee, Ellen; Lawton, Julia; Pollard, Daniel; Waugh, Norman; Amiel, Stephanie; Barnard, Katharine; Beckwith, Anita; Brennan, Alan; Campbell, Michael; Cooper, Cindy; Dimairo, Munyaradzi; Dixon, Simon; Elliott, Jackie; Evans, Mark; Green, Fiona; Hackney, Gemma; Hammond, Peter; Hallowell, Nina; Jaap, Alan; Kennon, Brian; Kirkham, Jackie; Lindsay, Robert; Mansell, Peter; Papaioannou, Diana; Rankin, David; Royle, Pamela; Smithson, W Henry; Taylor, Carolin

2017-01-01

BACKGROUND Insulin is generally administered to people with type 1 diabetes mellitus (T1DM) using multiple daily injections (MDIs), but can also be delivered using infusion pumps. In the UK, pumps are recommended for patients with the greatest need and adult use is less than in comparable countries. Previous trials have been small, of short duration and have failed to control for training in insulin adjustment. OBJECTIVE To assess the clinical effectiveness and cost-effectiveness of pump therapy compared with MDI for adults with T1DM, with both groups receiving equivalent structured training in flexible insulin therapy. DESIGN Pragmatic, multicentre, open-label, parallel-group cluster randomised controlled trial, including economic and psychosocial evaluations. After participants were assigned a group training course, courses were randomly allocated in pairs to either pump or MDI. SETTING Eight secondary care diabetes centres in the UK. PARTICIPANTS Adults with T1DM for > 12 months, willing to undertake intensive insulin therapy, with no preference for pump or MDI, or a clinical indication for pumps. INTERVENTIONS Pump or MDI structured training in flexible insulin therapy, followed up for 2 years. MDI participants used insulin analogues. Pump participants used a Medtronic Paradigm(®) Veo(TM) (Medtronic, Watford, UK) with insulin aspart (NovoRapid, Novo Nordisk, Gatwick, UK). MAIN OUTCOME MEASURES Primary outcome - change in glycated haemoglobin (HbA1c) at 2 years in participants whose baseline HbA1c was ≥ 7.5% (58 mmol/mol). Key secondary outcome - proportion of participants with HbA1c ≤ 7.5% at 2 years. Other outcomes at 6, 12 and 24 months - moderate and severe hypoglycaemia; insulin dose; body weight; proteinuria; diabetic ketoacidosis; quality of life (QoL); fear of hypoglycaemia; treatment satisfaction; emotional well-being; qualitative interviews with participants and staff (2 weeks), and participants (6 months); and ICERs in trial and modelled estimates of cost-effectiveness. RESULTS We randomised 46 courses comprising 317 participants: 267 attended a Dose Adjustment For Normal Eating course (132 pump; 135 MDI); 260 were included in the intention-to-treat analysis, of which 235 (119 pump; 116 MDI) had baseline HbA1c of ≥ 7.5%. HbA1c and severe hypoglycaemia improved in both groups. The drop in HbA1c% at 2 years was 0.85 on pump and 0.42 on MDI. The mean difference (MD) in HbA1c change at 2 years, at which the baseline HbA1c was ≥ 7.5%, was -0.24% [95% confidence interval (CI) -0.53% to 0.05%] in favour of the pump (p = 0.098). The per-protocol analysis showed a MD in change of -0.36% (95% CI -0.64% to -0.07%) favouring pumps (p = 0.015). Pumps were not cost-effective in the base case and all of the sensitivity analyses. The pump group had greater improvement in diabetes-specific QoL diet restrictions, daily hassle plus treatment satisfaction, statistically significant at 12 and 24 months and supported by qualitative interviews. LIMITATION Blinding of pump therapy was not possible, although an objective primary outcome was used. CONCLUSION Adding pump therapy to structured training in flexible insulin therapy did not significantly enhance glycaemic control or psychosocial outcomes in adults with T1DM. RESEARCH PRIORITY To understand why few patients achieve a HbA1c of < 7.5%, particularly as glycaemic control is worse in the UK than in other European countries. TRIAL REGISTRATION Current Controlled Trials ISRCTN61215213. FUNDING This project was funded by the National Institute for Health Research (NIHR) Health Technology Assessment programme and will be published in full in Health Technology Assessment; Vol. 21, No. 20. See the NIHR Journals Library website for further project information. PMID:28440211

Closed-Loop Insulin Delivery for Adults with Type 1 Diabetes Undertaking High-Intensity Interval Exercise Versus Moderate-Intensity Exercise: A Randomized, Crossover Study.

PubMed

Jayawardene, Dilshani C; McAuley, Sybil A; Horsburgh, Jodie C; Gerche, André La; Jenkins, Alicia J; Ward, Glenn M; MacIsaac, Richard J; Roberts, Timothy J; Grosman, Benyamin; Kurtz, Natalie; Roy, Anirban; O'Neal, David N

2017-06-01

We aimed to compare closed-loop glucose control for people with type 1 diabetes undertaking high-intensity interval exercise (HIIE) versus moderate-intensity exercise (MIE). Adults with type 1 diabetes established on insulin pumps undertook HIIE and MIE stages in random order during automated insulin delivery via a closed-loop system (Medtronic). Frequent venous sampling for glucose, lactate, ketones, insulin, catecholamines, cortisol, growth hormone, and glucagon levels was performed. The primary outcome was plasma glucose <4.0 mmol/L for ≥15 min, from exercise commencement to 120 min postexercise. Secondary outcomes included continuous glucose monitoring and biochemical parameters. Twelve adults (age mean ± standard deviation 40 ± 13 years) were recruited; all completed the study. Plasma glucose of one participant fell to 3.4 mmol/L following MIE completion; no glucose levels were <4.0 mmol/L for HIIE (primary outcome). There were no glucose excursions >15.0 mmol/L for either stage. Mean (±standard error) plasma glucose did not differ between stages pre-exercise; was higher during exercise in HIIE than MIE (11.3 ± 0.5 mmol/L vs. 9.7 ± 0.6 mmol/L, respectively; P < 0.001); and remained higher until 60 min postexercise. There were no differences in circulating free insulin before, during, or postexercise. During HIIE compared with MIE, there were greater increases in lactate (P < 0.001), catecholamines (all P < 0.05), and cortisol (P < 0.001). Ketones increased more with HIIE than MIE postexercise (P = 0.031). Preliminary findings suggest that closed-loop glucose control is safe for people undertaking HIIE and MIE. However, the management of the postexercise rise in ketones secondary to counter-regulatory hormone-induced insulin resistance observed with HIIE may represent a challenge for closed-loop systems.

SELF BLOOD GLUCOSE MONITORING UNDERESTIMATES HYPERGLYCEMIA AND HYPOGLYCEMIA AS COMPARED TO CONTINUOUS GLUCOSE MONITORING IN TYPE 1 AND TYPE 2 DIABETES.

PubMed

Mangrola, Devna; Cox, Christine; Furman, Arianne S; Krishnan, Sridevi; Karakas, Sidika E

2018-01-01

When glucose records from self blood glucose monitoring (SBGM) do not reflect estimated average glucose from glycosylated hemoglobin (HgBA1) or when patients' clinical symptoms are not explained by their SBGM records, clinical management of diabetes becomes a challenge. Our objective was to determine the magnitude of differences in glucose values reported by SBGM versus those documented by continuous glucose monitoring (CGM). The CGM was conducted by a clinical diabetes educator (CDE)/registered nurse by the clinic protocol, using the Medtronic iPRO2 ™ system. Patients continued SBGM and managed their diabetes without any change. Data from 4 full days were obtained, and relevant clinical information was recorded. De-identified data sets were provided to the investigators. Data from 61 patients, 27 with type 1 diabetes (T1DM) and 34 with T2DM were analyzed. The lowest, highest, and average glucose recorded by SBGM were compared to the corresponding values from CGM. The lowest glucose values reported by SBGM were approximately 25 mg/dL higher in both T1DM ( P = .0232) and T2DM ( P = .0003). The highest glucose values by SBGM were approximately 30 mg/dL lower in T1DM ( P = .0005) and 55 mg/dL lower in T2DM ( P<.0001). HgBA1c correlated with the highest and average glucose by SBGM and CGM. The lowest glucose values were seen most frequently during sleep and before breakfast; the highest were seen during the evening and postprandially. SBGM accurately estimates the average glucose but underestimates glucose excursions. CGM uncovers glucose patterns that common SBGM patterns cannot. CDE = certified diabetes educator; CGM = continuous glucose monitoring; HgBA1c = glycosylated hemoglobin; MAD = mean absolute difference; SBGM = self blood glucose monitoring; T1DM = type 1 diabetes; T2DM = type 2 diabetes.

Do Perceptions of Insulin Pump Usability Impact Attitudes Toward Insulin Pump Therapy? A Pilot Study of Individuals With Type 1 and Insulin-Treated Type 2 Diabetes

PubMed Central

Gilgen, Emily

2014-01-01

Background: We assessed the impact of perceived insulin pump usability on attitudes toward insulin pump therapy in diabetic individuals currently treated with multiple daily insulin injections (MDI). Method: This comparative, single-arm study recruited 28 adults with type 1 (n = 16) and insulin-treated type 2 diabetes (n = 12) to evaluate 2 current insulin pumps: Medtronic Revel 723 (Pump 1), Asante Snap Insulin Pump (Pump 2). Participants were randomized 1:1 to 1 of 2 assessment sequences: Pump 1 followed by Pump 2; and Pump 2 followed by Pump 1. Structured observational protocols were utilized to assess participants’ ability and time required to learn/perform common tasks associated with pump setup/use. Participants used a modified version of the System Usability Scale (SUS) and investigator-developed questionnaires to rate pump usability and task difficulty; pre-post questionnaires assessed changes in attitudes toward insulin pump therapy. Results: All participants completed the study. SUS scores showed Pump 2 to be more usable than Pump 1 on all usability attributes. Participants rated Pump 2 more positively than Pump 1, overall mean SUS scores of 5.7 versus 4.1 respectively, F(1, 52) = 32.7, P < .001, and SUS scores were higher if participants used the Pump 2 last, 5.3 versus 4.4 for Pump 1 last, F(1, 52) = 10.8, P < .01. Pump 2 was preferred for all tasks: manual bolus (86%), bolus calculation (71%), managing basal rates (93%), interpreting alarms (96%), transferring settings (100%), changing insulin and infusion sets (93%), all P < .05. Conclusions: Perceptions of pump usability can directly impact acceptance and use of features that may benefit those who wear them. Simpler pump devices that decrease perceptions of complexity may encourage broader use of this technology. PMID:25269659

Safety and efficacy of the predictive low glucose management system in the prevention of hypoglycaemia: protocol for randomised controlled home trial to evaluate the Suspend before low function

PubMed Central

Abraham, M B; Nicholas, J A; Ly, T T; Roby, H C; Paramalingam, N; Fairchild, J; King, B R; Ambler, G R; Cameron, F; Davis, E A; Jones, T W

2016-01-01

Introduction Innovations with sensor-augmented pump therapy (SAPT) to reduce hypoglycaemia in patients with type 1 diabetes are an ongoing area of research. The predictive low glucose management (PLGM) system incorporates continuous glucose sensor data into an algorithm and suspends basal insulin before the occurrence of hypoglycaemia. The system was evaluated in in-clinic studies, and has informed the parameters of a larger home trial to study its efficacy and safety in real life. Methods and analysis The aim of this report is to describe the study design and outcome measures for the trial. This is a 6-month, multicentre, randomised controlled home trial to test the PLGM system in children and adolescents with type 1 diabetes. The system is available in the Medtronic MiniMed 640G pump as the ‘Suspend before low’ feature. Following a run-in period, participants are randomised to either the control arm with SAPT alone or the intervention arm with SAPT and Suspend before low. The primary aim of this study is to evaluate the time spent hypoglycaemic (sensor glucose <3.5 mmol/L) with and without the system. The secondary aims are to determine the number of hypoglycaemic events, the time spent hyperglycaemic, and to evaluate safety with ketosis and changes in glycated haemoglobin. The study also aims to assess the changes in counter-regulatory hormone responses to hypoglycaemia evaluated by a hyperinsulinaemic hypoglycaemic clamp in a subgroup of patients with impaired awareness. Validated questionnaires are used to measure the fear of hypoglycaemia and the impact on the quality of life to assess burden of the disease. Ethics and dissemination Ethics committee permissions were gained from respective Institutional Review boards. The findings of the study will provide high quality evidence of the ability of the system in the prevention of hypoglycaemia in real life. Trial registration number ACTRN12614000510640, Pre-results. PMID:27084290

Nocturnal continuous glucose monitoring: accuracy and reliability of hypoglycemia detection in patients with type 1 diabetes at high risk of severe hypoglycemia.

PubMed

Bay, Christiane; Kristensen, Peter Lommer; Pedersen-Bjergaard, Ulrik; Tarnow, Lise; Thorsteinsson, Birger

2013-05-01

A reliable method to detect biochemical nocturnal hypoglycemia is highly needed, especially in patients with recurrent severe hypoglycemia. We evaluated reliability of nocturnal continuous glucose monitoring (CGM) in patients with type 1 diabetes at high risk of severe hypoglycemia. Seventy-two type 1 diabetes patients with recurrent severe hypoglycemia (two or more events within the last year) participated for 4 nights in blinded CGM recordings (Guardian(®) REAL-Time CGMS and Sof-Sensor(®); Medtronic MiniMed, Northridge, CA). Blood was drawn hourly from 23:00 to 07:00 h for plasma glucose (PG) measurements (gold standard). Valid data were obtained in 217 nights. The sensitivity of CGM was 65% (95% confidence interval, 53-77%) below 4 mmol/L, 40% (24-56%) below 3 mmol/L, and 17% (0-47%) below 2.2 mmol/L. PG and CGM readings correlated in the total measurement range (Spearman's ρ=0.82; P<0.001). In the normo- and hyperglycemic ranges CGM underestimated PG by 1.1 mmol/L (0.9-1.2 mmol/L) (P<0.001); in contrast, in the hypoglycemic range (PG<4 mmol/L) CGM overestimated PG levels by 1.0 mmol/L (P<0.001). The mean absolute relative differences in the hypo- (≤3.9 mmol/L), normo- (4-9.9 mmol/L), and hyperglycemic (≥10 mmol/L) ranges were 45% (37-53%), 23% (22-25%), and 20% (19-21%), respectively. Continuous glucose error grid analysis indicated a clinical accuracy of 56%, 99%, and 93% in the hypo-, normo-, and hyperglycemic ranges, respectively. The accuracy in the hypoglycemic range of nocturnal CGM data using Sof-Sensor is suboptimal in type 1 diabetes patients at high risk of severe hypoglycemia. To ensure clinical useful sensitivity in detection of nocturnal hypoglycemic episodes, an alarm threshold should not be lower than 4 mmol/L.

The Impact of Cryoballoon Versus Radiofrequency Ablation for Paroxysmal Atrial Fibrillation on Healthcare Utilization and Costs: An Economic Analysis From the FIRE AND ICE Trial.

PubMed

Chun, K R Julian; Brugada, Josep; Elvan, Arif; Gellér, Laszlo; Busch, Matthias; Barrera, Alberto; Schilling, Richard J; Reynolds, Matthew R; Hokanson, Robert B; Holbrook, Reece; Brown, Benedict; Schlüter, Michael; Kuck, Karl-Heinz

2017-07-27

This study sought to assess payer costs following cryoballoon or radiofrequency current (RFC) catheter ablation of paroxysmal atrial fibrillation in the randomized FIRE AND ICE trial. A trial period analysis of healthcare costs evaluated the impact of ablation modality (cryoballoon versus RFC) on differences in resource use and associated payer costs. Analyses were based on repeat interventions, rehospitalizations, and cardioversions during the trial, with unit costs based on 3 national healthcare systems (Germany [€], the United Kingdom [£], and the United States [$]). Total payer costs were calculated by applying standard unit costs to hospital stays, using International Classification of Diseases, 10th Revision diagnoses and procedure codes that were mapped to country-specific diagnosis-related groups. Patients (N=750) randomized 1:1 to cryoballoon (n=374) or RFC (n=376) ablation were followed for a mean of 1.5 years. Resource use was lower in the cryoballoon than the RFC group (205 hospitalizations and/or interventions in 122 patients versus 268 events in 154 patients). The cost differences per patient in mean total payer costs during follow-up were €640, £364, and $925 in favor of cryoballoon ablation ( P =0.012, 0.013, and 0.016, respectively). This resulted in trial period total cost savings of €245 000, £140 000, and $355 000. When compared with RFC ablation, cryoballoon ablation was associated with a reduction in resource use and payer costs. In all 3 national healthcare systems analyzed, this reduction resulted in substantial trial period cost savings, primarily attributable to fewer repeat ablations and a reduction in cardiovascular rehospitalizations with cryoballoon ablation. URL: http://www.clinicaltrials.gov. Identifier: NCT01490814. © 2017 The Authors and Medtronic. Published on behalf of the American Heart Association, Inc., by Wiley.

Merits and limitations of the mode switching rate stabilization pacing algorithms in the implantable cardioverter defibrillator.

PubMed

Dijkman, B; Wellens, H J

2001-09-01

The 7250 Jewel AF Medtronic model of ICD is the first implantable device in which both therapies for atrial arrhythmias and pacing algorithms for atrial arrhythmia prevention are available. Feasibility of that extensive atrial arrhythmia management requires correct and synergic functioning of different algorithms to control arrhythmias. The ability of the new pacing algorithms to stabilize the atrial rate following termination of treated atrial arrhythmias was evaluated in the marker channel registration of 600 spontaneously occurring episodes in 15 patients with the Jewel AF. All patients (55+/-15 years) had structural heart disease and documented atrial and ventricular arrhythmias. Dual chamber rate stabilization pacing was present in 245 (41 %) of episodes following arrhythmia termination and was a part of the mode switching operation during which pacing was provided in the dynamic DDI mode. This algorithm could function as the atrial rate stabilization pacing only when there was a slow spontaneous atrial rhythm or in presence of atrial premature beats conducted to the ventricles with a normal AV time. In case of atrial premature beats with delayed or absent conduction to the ventricles and in case of ventricular premature beats, the algorithm stabilized the ventricular rate. The rate stabilization pacing in DDI mode during sinus rhythm following atrial arrhythmia termination was often extended in time due to the device-based definition of arrhythmia termination. This was also the case in patients, in whom the DDD mode with true atrial rate stabilization algorithm was programmed. The rate stabilization algorithms in the Jewel AF applied after atrial arrhythmia termination provide pacing that is not based on the timing of atrial events. Only under certain circumstances the algorithm can function as atrial rate stabilization pacing. Adjustments in availability and functioning of the rate stabilization algorithms might be of benefit for the clinical performance of pacing as part of device therapy for atrial arrhythmias.

Biomechanical analysis of occipitocervical stability afforded by three fixation techniques.

PubMed

Helgeson, Melvin D; Lehman, Ronald A; Sasso, Rick C; Dmitriev, Anton E; Mack, Andrew W; Riew, K Daniel

2011-03-01

Occipital condyle screws appear to be a novel technique that demands biomechanical consideration. It has the potential to achieve fixation anterior to the axis of rotation while offering a point of fixation in line with the C1/C2 screws. To compare the segmental stability and range of motion (ROM) of standard occipitocervical (OC) screw/rod and plate constructs versus a new technique that incorporates occipital condyle fixation. Human cadaveric biomechanical analysis. After intact analysis, 10 fresh-frozen human cadaveric OC spine specimens were instrumented bilaterally with C1 lateral mass screws and C2 pedicle screws. Additional occipital instrumentation was tested in random order under the following conditions: standard occipitocervical plate/rod system (Vertex Max; Medtronic, Inc., Minneapolis, MN, USA); occipital condyle screws alone; and occipital condyle screws with the addition of an eyelet screw placed into the occiput bilaterally. After nondestructive ROM testing, specimens were evaluated under computed tomography (CT) and underwent destructive forward flexion failure comparing Group 1 to Group 3. There was no significant difference in OC (Occiput-C1) axial rotation and flexion/extension ROM between the standard occipitocervical plate/rod system (Group 1) and the occipital condyle screws with one eyelet screw bilaterally (Group 3). Furthermore, the occipital condyle screws alone (Group 2) did allow significantly more flexion/extension compared with Group 1. Interestingly, the two groups with occipital condyle screws (Groups 2 and 3) had significantly less lateral bending compared with Group 1. During CT analysis, the mean occipital condyle width was 10.8 mm (range, 9.1-12.7 mm), and the mean condylar length was 24.3 mm (range, 20.2-28.5). On destructive testing, there was no significant difference in forward flexion failure between Groups 1 and 3. With instrumentation across the mobile OC junction, our results indicate that similar stability can be achieved with occipital condyle screws/eyelet screws compared with the standard occipitocervical plate/rod system. Published by Elsevier Inc.

How revealing are insertable loop recorders in pediatrics?

PubMed

Frangini, Patricia A; Cecchin, Frank; Jordao, Ligia; Martuscello, Maria; Alexander, Mark E; Triedman, John K; Walsh, Edward P; Berul, Charles I

2008-03-01

An insertable loop recorder (ILR) in patients with infrequent syncope or palpitations may be useful to decide management strategies, including clinical observation, medical therapy, pacemaker, or implantable cardioverter defibrillator (ICD). We sought to determine the diagnostic utility of the Reveal ILR (Medtronic, Inc., Minneapolis, MN, USA) in pediatric patients. Retrospective review of clinical data, indications, findings, and therapeutic decision in 27 consecutive patients who underwent ILR implantation from 1998-2007. The median age was 14.8 years (2-25 years). Indications were syncope in 24 patients and recurrent palpitations in three. Overall, eight patients had structural heart disease (six congenital heart disease, one hypertrophic cardiomyopathy, one Kawasaki), five had previous documented ventricular arrhythmias with negative evaluation including electrophysiology study, and three patients had QT prolongation. Tilt testing was performed in 10 patients, of which five had neurocardiogenic syncope but recurrent episodes despite medical therapy. After median three months (1-20 months), 17 patients presented with symptoms and the ILR memory was analyzed in 16 (no episode stored in one due to full device memory), showing asystole or transient atrioventricular (AV) block (2), sinus bradycardia (6), or normal sinus rhythm (8). Among asymptomatic patients, 3/10 had intermittent AV block or long pauses, automatically detected and stored by the ILR. In 19 of 20 patients, ILR was diagnostic (95%) and five subsequently underwent pacemaker implantation, while seven patients remained asymptomatic without ILR events. Notably, no life-threatening events were detected. The ILR was explanted in 22 patients after a median of 22 months, two due to pocket infection, 12 for battery depletion and eight after clear documentation of nonmalignant arrhythmia. The ILR in pediatrics is a useful adjunct to other diagnostic studies. Patient selection is critical as the ILR should not be utilized for malignant arrhythmias. A diagnosis is attained in the majority of symptomatic patients, predominantly bradyarrhythmias including pauses and intermittent AV block.

Integrity(®) bare-metal coronary stent-induced platelet and endothelial cell activation results in a higher risk of restenosis compared to Xience(®) everolimus-eluting stents in stable angina patients.

PubMed

Szük, Tibor; Fejes, Zsolt; Debreceni, Ildikó Beke; Kerényi, Adrienne; Édes, István; Kappelmayer, János; Nagy, Béla

2016-07-01

Drug-eluting stenting (DES) has become a reliable tool for coronary stenting; however, its direct effects on platelet and endothelium function differ from those of bare-metal stenting (BMS). This study involved a periprocedural analysis of various biomarkers of cellular activation after elective DES (Xience(®), Abbott Vascular, Santa Clara, CA, USA) or BMS (Integrity(®), Medtronic, Minneapolis, MI, USA). Forty-nine stable angina patients were recruited: 28 underwent BMS, and 21 received everolimus-eluting stents. Samples were collected (i) prior to stenting, (ii) at 24 hours after procedure, and (iii) after 1 month of dual antiplatelet therapy. Platelet activation was analyzed by surface P-selectin positivity in parallel with plasma levels of soluble P-selectin, CD40L and platelet-derived growth factor (PDGF). Endothelial cell (EC) activation was detected by measuring markers of early (von Willebrand factor) and delayed response (VCAM-1, ICAM-1, E-selectin). Patients were followed for 6 months for the occurrence of restenosis or stent thrombosis. Increased platelet activation was sustained regardless of stent type or antiplatelet medication. Concentrations of most EC markers were more elevated after BMS than after DES. No stent thrombosis was seen, but six BMS subjects displayed restenosis with significantly higher sCD40L (779 [397-899] vs. 381 [229-498] pg/mL; p = 0.032) and sICAM-1 (222 [181-272] vs. 162 [153-223] ng/mL; p = 0.046) levels than in those without complication, while DES patients exhibited significantly decreased PDGF (572 [428-626] vs. 244 [228-311] pg/mL; p = 0.004) after 1 month. Nonresponsiveness to antiplatelet drugs did not influence these changes. In conclusion, the degree of platelet and EC activation suggests that Xience(®) DES may be regarded a safer coronary intervention than Integrity(®) BMS, with a lower risk of in-stent restenosis.

Visualization and appearance of artifacts of leadless pacemaker systems in cardiac MRI : An experimental ex vivo study.

PubMed

Edlinger, Christoph; Granitz, Marcel; Paar, Vera; Jung, Christian; Pfeil, Alexander; Eder, Sarah; Wernly, Bernhard; Kammler, Jürgen; Hergan, Klaus; Hoppe, Uta C; Steinwender, Clemens; Lichtenauer, Michael; Kypta, Alexander

2018-05-23

Leadless pacemaker systems are an important upcoming device in clinical rhythmology. Currently two different products are available with the Micra system (Medtronic) being the most used in the clinical setting to date. The possibility to perform magnetic resonance imaging (MRI) is an important feature of modern pacemaker devices. Even though the Micra system is suitable for MRI, little is yet known about its impact on artifacts within the images. The aim of our ex vivo study was to perform cardiac MRI to quantify the artifacts and to evaluate if artifacts limit or inhibit the assessment of the surrounding myocardium. After ex vivo implantation of the leadless pacemaker (LP) in a porcine model, hearts were filled with saline solution and fixed on wooden sticks on a plastic container. The model was examined at 1.5 T and at 3 T using conventional sequences and T2 mapping sequences. In addition, conventional X‑rays and computed tomography (CT) scans were performed. Correct implantation of the LP could be performed in all hearts. In almost all MRI sequences the right ventricle and the septal region surrounding the (LP) were altered by an artifact and therefore would sustain limited assessment; however, the rest of the myocardium remained free of artifacts and evaluable for common radiologic diagnoses. A characteristic shamrock-shaped artifact was generated which appeared to be even more intense in magnitude and brightness when using 3 T compared to 1.5 T. The use of the Micra system in cardiac MRI appeared to be feasible. In our opinion, it will still be possible to make important clinical cardiac MRI diagnoses (the detection of major ischemic areas or inflammatory processes) in patients using the Micra system. We suggest the use of 1.5 T as the preferred method in clinical practice.

Exhausted implanted pulse generator in sacral nerve stimulation for faecal incontinence: What next in daily practice for patients?

PubMed

Duchalais, Emilie; Meurette, Guillaume; Perrot, Bastien; Wyart, Vincent; Kubis, Caroline; Lehur, Paul-Antoine

2016-02-01

The efficacy of sacral nerve stimulation in faecal incontinence relies on an implanted pulse generator known to have a limited lifespan. The long-term use of sacral nerve stimulation raises concerns about the true lifespan of generators. The aim of the study was to assess the lifespan of sacral nerve stimulation implanted pulse generators in daily practice, and the outcome of exhausted generator replacement, in faecal incontinent patients. Faecal incontinent patients with pulse generators (Medtronic Interstim™ or InterstimII™) implanted in a single centre from 2001 to 2014 were prospectively followed up. Generator lifespan was measured according to the Kaplan-Meier method. Patients with a generator explanted/turned off before exhaustion were excluded. Morbidity of exhausted generator replacement and the outcome (Cleveland Clinic Florida Faecal Incontinence (CCF-FI) and Faecal Incontinence Quality of Life (FIQL) scores) were recorded. Of 135 patients with an implanted pulse generator, 112 (InterstimII 66) were included. Mean follow-up was 4.9 ± 2.8 years. The generator reached exhaustion in 29 (26%) cases. Overall median lifespan of an implanted pulse generator was approximately 9 years (95% CI 8-9.2). Interstim and InterstimII 25th percentile lifespan was 7.2 (CI 6.4-8.3) and 5 (CI 4-not reached) years, respectively. After exhaustion, generators were replaced, left in place or explanted in 23, 2 and 4 patients, respectively. Generator replacement was virtually uneventful. CCF-FI/FIQL scores remained unchanged after generator replacement (CCF-FI 8 ± 2 vs 7 ± 3; FIQL 3 ± 0.6 vs 3 ± 0.5; p = ns). In this study, the implanted pulse generator observed median lifespan was 9 years. After exhaustion, generators were safely and efficiently replaced. The study also gives insight into long-term needs and costs of sacral nerve stimulation (SNS) therapy.

Test-retest reliability of a continuous glucose monitoring system in individuals with type 2 diabetes.

PubMed

Terada, Tasuku; Loehr, Sarah; Guigard, Emmanuel; McCargar, Linda J; Bell, Gordon J; Senior, Peter; Boulé, Normand G

2014-08-01

This study determined the test-retest reliability of a continuous glucose monitoring system (CGMS) (iPro™2; Medtronic, Northridge, CA) under standardized conditions in individuals with type 2 diabetes (T2D). Fourteen individuals with T2D spent two nonconsecutive days in a calorimetry unit. On both days, meals, medication, and exercise were standardized. Glucose concentrations were measured continuously by CGMS, from which daily mean glucose concentration (GLU(mean)), time spent in hyperglycemia (t(>10.0 mmol/L)), and meal, exercise, and nocturnal mean glucose concentrations, as well as glycemic variability (SD(w), percentage coefficient of variation [%cv(w)], mean amplitude of glycemic excursions [MAGEc, MAGE(ave), and MAGE(abs.gos)], and continuous overlapping net glycemic action [CONGA(n)]) were estimated. Absolute and relative reliabilities were investigated using coefficient of variation (CV) and intraclass correlation, respectively. Relative reliability ranged from 0.77 to 0.95 (P<0.05) for GLU(mean) and meal, exercise, and nocturnal glycemia with CV ranging from 3.9% to 11.7%. Despite significant relative reliability (R=0.93; P<0.01), t(>10.0 mmol/L) showed larger CV (54.7%). Among the different glycemic variability measures, a significant between-day difference was observed in MAGEc, MAGE(ave), CONGA6, and CONGA12. The remaining measures (i.e., SD(w), %cv(w), MAGE(abs.gos), and CONGA1-4) indicated no between-day differences and significant relative reliability. In individuals with T2D, CGMS-estimated glycemic profiles were characterized by high relative and absolute reliability for both daily and shorter-term measurements as represented by GLUmean and meal, exercise, and nocturnal glycemia. Among the different methods to calculate glycemic variability, our results showed SD(w), %cv(w), MAGE(abs.gos), and CONGAn with n ≤ 4 were reliable measures. These results suggest the usefulness of CGMS in clinical trials utilizing repeated measured.

Analysis of implantable defibrillator longevity under clinical circumstances: implications for device selection.

PubMed

Knops, Paul; Theuns, Dominic A M J; Res, Jan C J; Jordaens, Luc

2009-10-01

Information about implantable cardioverter-defibrillator (ICD) longevity is mostly calculated from measurements under ideal laboratory conditions. However, little information about longevity under clinical circumstances is available. This survey gives an overview on ICD service times and generator replacements in a cohort of consecutive ICD patients. Indications for replacement were classified as a normal end-of-service (EOS), premature EOS, system malfunction, infection and device advisory, or recall actions. From the premature and normal EOS group, longevity from single-chamber (SC), dual-chamber (DC), and cardiac resynchronization therapy defibrillator (CRT-D), rate-responsive (RR) settings, high output (HO) stimulation, and indication for ICD therapy was compared. Differences between brands were compared as well. In a total of 854 patients, 203 ICD replacements (165 patients) were recorded. Premature and normal EOS replacements consisted of 32 SC, 98 DC and 24 CRT-D systems. Longevity was significantly longer in SC systems compared to DC and CRT-D systems (54 +/- 19 vs. 40 +/- 17 and 42 +/- 15 months; P = 0.008). Longevity between non-RR (n = 143) and RR (n = 11) settings was not significantly different (43 +/- 18 vs. 45 +/- 13 months) as it also was not for HO versus non-HO stimulation (43 +/- 19 vs. 46 +/- 17 months). Longevity of ICDs was not significantly different between primary and secondary prevention (42 +/- 19 vs. 44 +/- 18 months). The average longevity on account of a device-based EOS message was 43 +/- 18 months. Average longevity for Biotronik (BIO, n = 72) was 33 +/- 10 months, for ELA Medical (ELA, n = 12) 44 +/- 17 months, for Guidant (GDT, n = 36) 49 +/- 12 months, for Medtronic (MDT, n = 29) 62 +/- 22 months, and for St. Jude Medical (SJM, n = 5) 31 +/- 9 months (P < 0.001). SC ICD generators had a longer service time compared to DC and CRT-D systems. No influence of indication for ICD therapy and HO stimulation on generator longevity was observed in this study. MDT ICDs had the longest service time.

Evaluating the clinical accuracy of two continuous glucose sensors using continuous glucose-error grid analysis.

PubMed

Clarke, William L; Anderson, Stacey; Farhy, Leon; Breton, Marc; Gonder-Frederick, Linda; Cox, Daniel; Kovatchev, Boris

2005-10-01

To compare the clinical accuracy of two different continuous glucose sensors (CGS) during euglycemia and hypoglycemia using continuous glucose-error grid analysis (CG-EGA). FreeStyle Navigator (Abbott Laboratories, Alameda, CA) and MiniMed CGMS (Medtronic, Northridge, CA) CGSs were applied to the abdomens of 16 type 1 diabetic subjects (age 42 +/- 3 years) 12 h before the initiation of the study. Each system was calibrated according to the manufacturer's recommendations. Each subject underwent a hyperinsulinemic-euglycemic clamp (blood glucose goal 110 mg/dl) for 70-210 min followed by a 1-mg.dl(-1).min(-1) controlled reduction in blood glucose toward a nadir of 40 mg/dl. Arterialized blood glucose was determined every 5 min using a Beckman Glucose Analyzer (Fullerton, CA). CGS glucose recordings were matched to the reference blood glucose with 30-s precision, and rates of glucose change were calculated for 5-min intervals. CG-EGA was used to quantify the clinical accuracy of both systems by estimating combined point and rate accuracy of each system in the euglycemic (70-180 mg/dl) and hypoglycemic (<70 mg/dl) ranges. A total of 1,104 data pairs were recorded in the euglycemic range and 250 data pairs in the hypoglycemic range. Overall correlation between CGS and reference glucose was similar for both systems (Navigator, r = 0.84; CGMS, r = 0.79, NS). During euglycemia, both CGS systems had similar clinical accuracy (Navigator zones A + B, 88.8%; CGMS zones A + B, 89.3%, NS). However, during hypoglycemia, the Navigator was significantly more clinically accurate than the CGMS (zones A + B = 82.4 vs. 61.6%, Navigator and CGMS, respectively, P < 0.0005). CG-EGA is a helpful tool for evaluating and comparing the clinical accuracy of CGS systems in different blood glucose ranges. CG-EGA provides accuracy details beyond other methods of evaluation, including correlational analysis and the original EGA.

Accuracy and reliability of continuous glucose monitoring systems: a head-to-head comparison.

PubMed

Luijf, Yoeri M; Mader, Julia K; Doll, Werner; Pieber, Thomas; Farret, Anne; Place, Jerome; Renard, Eric; Bruttomesso, Daniela; Filippi, Alessio; Avogaro, Angelo; Arnolds, Sabine; Benesch, Carsten; Heinemann, Lutz; DeVries, J Hans

2013-08-01

This study assessed the accuracy and reliability of three continuous glucose monitoring (CGM) systems. We studied the Animas® (West Chester, PA) Vibe™ with Dexcom® (San Diego, CA) G4™ version A sensor (G4A), the Abbott Diabetes Care (Alameda, CA) Freestyle® Navigator I (NAV), and the Medtronic (Northridge, CA) Paradigm® with Enlite™ sensor (ENL) in 20 patients with type 1 diabetes mellitus. All systems were investigated both in a clinical research center (CRC) and at home. In the CRC, patients received a meal with a delayed and increased insulin dose to induce a postprandial glucose peak and nadir. Hereafter, randomization determined which two of the three systems would be worn at home until the end of functioning, attempting use beyond manufacturer-specified lifetime. Patients performed at least five reference finger sticks per day. An analysis of variance was performed on all data points ≥15 min apart. Overall average mean absolute relative difference (MARD) (SD) measured at the CRC was 16.5% (14.3%) for NAV and 16.4% (15.6%) for ENL, outperforming G4A at 20.5% (18.2%) (P<0.001). Overall MARD when assessed at home was 14.5% (16.7%) for NAV and 16.5 (18.8%) for G4A, outperforming ENL at 18.9% (23.6%) (P=0.006). Median time until end of functioning was similar: 10.0 (1.0) days for G4A, 8.0 (3.5) days for NAV, and 8.0 (1.5) days for ENL (P=0.119). In the CRC, G4A was less accurate than NAV and ENL sensors, which seemed comparable. However, at home, ENL was less accurate than NAV and G4A. Moreover, CGM systems often show sufficient accuracy to be used beyond manufacturer-specified lifetime.

Sacral neuromodulation for lower urinary tract dysfunction and impact on erectile function.

PubMed

Lombardi, Giuseppe; Mondaini, Nicola; Giubilei, Gianluca; Macchiarella, Angelo; Lecconi, Filippo; Del Popolo, Giulio

2008-09-01

The first sacral nerve stimulators were for urinary urgency incontinence, urgency-frequency, and nonobstructive urinary retention. Since then, observations have been made for benefits beyond voiding disorders. To evaluate if sacral neuromodulation (SNM) using the InterStim system (Medtronic Inc., Minneapolis, MN, USA) improves erectile function. From January 1999 to January 2007, 54 males, mean age 42.8, underwent a permanent SNM for lower urinary tract symptoms (LUTS). Pre-SNM only subjects with concomitant erectile impairment according to the five-item version of the International Index of Erectile Function (IIEF-5), with normal blood sexual hormonal status, and responding to an intracavernous injection test 10 microg were enrolled in our study. Three months after permanent implantation, the IIEF-5 was completed again. Those who benefited significantly in erectile function completed the IIEF-5 semiannually. A final checkup was performed in July 2007. A score of IIEF-5 equal to or higher than 25% compared to baseline indicated remarkable clinical enhancement. Presurgery, two patients were excluded. Overall, 22 subjects (42.3%) showed erectile impairment (14 were neurogenic). In the first visit post-SNM, five retentionists of neurogenic origin and two with overactive bladder syndrome of idiopathic origin achieved noticeable erectile improvement. Their median IIEF-5 score shifted from 14.6 to 22.2, and 15.5 to 22.5, respectively. During follow-up, two neurogenics lost the benefits concerning voiding and erection and recovered them after a new implant in the contralateral sacral S3 root. In the final visit, the seven responders reached an IIEF-5 score of at least 22. Our study showed a clinically important benefit of sexual function mainly for neurogenic retentionists. Future research should test SNM in a larger sample of subjects, exclusively with sexual dysfunctions, in order to better understand the mechanism of action of SNM on erectile function.

Transcatheter aortic-valve replacement with a self-expanding prosthesis.

PubMed

Adams, David H; Popma, Jeffrey J; Reardon, Michael J; Yakubov, Steven J; Coselli, Joseph S; Deeb, G Michael; Gleason, Thomas G; Buchbinder, Maurice; Hermiller, James; Kleiman, Neal S; Chetcuti, Stan; Heiser, John; Merhi, William; Zorn, George; Tadros, Peter; Robinson, Newell; Petrossian, George; Hughes, G Chad; Harrison, J Kevin; Conte, John; Maini, Brijeshwar; Mumtaz, Mubashir; Chenoweth, Sharla; Oh, Jae K

2014-05-08

We compared transcatheter aortic-valve replacement (TAVR), using a self-expanding transcatheter aortic-valve bioprosthesis, with surgical aortic-valve replacement in patients with severe aortic stenosis and an increased risk of death during surgery. We recruited patients with severe aortic stenosis who were at increased surgical risk as determined by the heart team at each study center. Risk assessment included the Society of Thoracic Surgeons Predictor Risk of Mortality estimate and consideration of other key risk factors. Eligible patients were randomly assigned in a 1:1 ratio to TAVR with the self-expanding transcatheter valve (TAVR group) or to surgical aortic-valve replacement (surgical group). The primary end point was the rate of death from any cause at 1 year, evaluated with the use of both noninferiority and superiority testing. A total of 795 patients underwent randomization at 45 centers in the United States. In the as-treated analysis, the rate of death from any cause at 1 year was significantly lower in the TAVR group than in the surgical group (14.2% vs. 19.1%), with an absolute reduction in risk of 4.9 percentage points (upper boundary of the 95% confidence interval, -0.4; P<0.001 for noninferiority; P = 0.04 for superiority). The results were similar in the intention-to-treat analysis. In a hierarchical testing procedure, TAVR was noninferior with respect to echocardiographic indexes of valve stenosis, functional status, and quality of life. Exploratory analyses suggested a reduction in the rate of major adverse cardiovascular and cerebrovascular events and no increase in the risk of stroke. In patients with severe aortic stenosis who are at increased surgical risk, TAVR with a self-expanding transcatheter aortic-valve bioprosthesis was associated with a significantly higher rate of survival at 1 year than surgical aortic-valve replacement. (Funded by Medtronic; U.S. CoreValve High Risk Study ClinicalTrials.gov number, NCT01240902.).

Surgical or Transcatheter Aortic-Valve Replacement in Intermediate-Risk Patients.

PubMed

Reardon, Michael J; Van Mieghem, Nicolas M; Popma, Jeffrey J; Kleiman, Neal S; Søndergaard, Lars; Mumtaz, Mubashir; Adams, David H; Deeb, G Michael; Maini, Brijeshwar; Gada, Hemal; Chetcuti, Stanley; Gleason, Thomas; Heiser, John; Lange, Rüdiger; Merhi, William; Oh, Jae K; Olsen, Peter S; Piazza, Nicolo; Williams, Mathew; Windecker, Stephan; Yakubov, Steven J; Grube, Eberhard; Makkar, Raj; Lee, Joon S; Conte, John; Vang, Eric; Nguyen, Hang; Chang, Yanping; Mugglin, Andrew S; Serruys, Patrick W J C; Kappetein, Arie P

2017-04-06

Although transcatheter aortic-valve replacement (TAVR) is an accepted alternative to surgery in patients with severe aortic stenosis who are at high surgical risk, less is known about comparative outcomes among patients with aortic stenosis who are at intermediate surgical risk. We evaluated the clinical outcomes in intermediate-risk patients with severe, symptomatic aortic stenosis in a randomized trial comparing TAVR (performed with the use of a self-expanding prosthesis) with surgical aortic-valve replacement. The primary end point was a composite of death from any cause or disabling stroke at 24 months in patients undergoing attempted aortic-valve replacement. We used Bayesian analytical methods (with a margin of 0.07) to evaluate the noninferiority of TAVR as compared with surgical valve replacement. A total of 1746 patients underwent randomization at 87 centers. Of these patients, 1660 underwent an attempted TAVR or surgical procedure. The mean (±SD) age of the patients was 79.8±6.2 years, and all were at intermediate risk for surgery (Society of Thoracic Surgeons Predicted Risk of Mortality, 4.5±1.6%). At 24 months, the estimated incidence of the primary end point was 12.6% in the TAVR group and 14.0% in the surgery group (95% credible interval [Bayesian analysis] for difference, -5.2 to 2.3%; posterior probability of noninferiority, >0.999). Surgery was associated with higher rates of acute kidney injury, atrial fibrillation, and transfusion requirements, whereas TAVR had higher rates of residual aortic regurgitation and need for pacemaker implantation. TAVR resulted in lower mean gradients and larger aortic-valve areas than surgery. Structural valve deterioration at 24 months did not occur in either group. TAVR was a noninferior alternative to surgery in patients with severe aortic stenosis at intermediate surgical risk, with a different pattern of adverse events associated with each procedure. (Funded by Medtronic; SURTAVI ClinicalTrials.gov number, NCT01586910 .).

Randomized comparison of distal and proximal cerebral protection during carotid artery stenting.

PubMed

Cano, Manuel N; Kambara, Antônio M; de Cano, Silvia J F; Pezzi Portela, Luiz Antônio; Paes, Ângela Tavares; Costa, J Ribamar; Abizaid, Alexandre Antônio Cunha; Moreira, Samuel Martins; Sousa, Amanda G M R; Sousa, J Eduardo Moraes Rego

2013-11-01

This study sought to randomly compare cerebral protection with ANGIOGUARD (Cordis Corporation, Bridgewater, New Jersey) with Mo.Ma (Invatec/Medtronic Vascular Inc, Santa Rosa, California) during carotid artery stenting (CAS), using diffusion-weighted magnetic resonance imaging (DW-MRI) to detect new ischemic cerebral lesions. The number, size, and location of lesions were analyzed. The choice of the type of cerebral protection during CAS is controversial. From July 2008 to July 2011, 60 patients undergoing CAS were randomized to ANGIOGUARD or Mo.Ma, distributed by chance, 30 patients for each group. All patients underwent DW-MRI before and after CAS. An independent neuroradiologist blinded to the cerebral protection used analyzed the images. Univariate and multivariate logistic models were fitted to analyze new ischemic lesions. Alternatively, a propensity score approach was used to reduce the bias due to differences between the groups. For the number of lesions, we used Poisson regression models. New ischemic lesions seen on DW-MRI were present in 63.3% of the ANGIOGUARD group versus 66.7% of the Mo.Ma cohort (p = 0.787). The number of ischemic cerebral lesions per patient, when present, was significantly lower in the Mo.Ma group (a median of 6 lesions per patient vs. a median of 10 in the ANGIOGUARD, p < 0.001). Most lesions were small (<0.5 mm) and localized in the ipsilateral territory. One patient in the ANGIOGUARD group had a minor stroke during CAS (1.66%). New ischemic lesions seen on DW-MRI were present in both groups in >60%, but the number of lesions per patient was greater in the ANGIOGUARD group. No death or disabling stroke occurred during at least 1 year of follow-up in both cohorts. Copyright © 2013 American College of Cardiology Foundation. Published by Elsevier Inc. All rights reserved.

Right ventricular remodelling after transcatheter pulmonary valve implantation.

PubMed

Pagourelias, Efstathios D; Daraban, Ana M; Mada, Razvan O; Duchenne, Jürgen; Mirea, Oana; Cools, Bjorn; Heying, Ruth; Boshoff, Derize; Bogaert, Jan; Budts, Werner; Gewillig, Marc; Voigt, Jens-Uwe

2017-09-01

To define the optimal timing for percutaneous pulmonary valve implantation (PPVI) in patients with severe pulmonary regurgitation (PR) after Fallot's Tetralogy (ToF) correction. PPVI among the aforementioned patients is mainly driven by symptoms or by severe right ventricular (RV) dilatation/dysfunction. The optimal timing for PPVI is still disputed. Twenty patients [age 13.9 ± 9.2 years, (range 4.3-44.9), male 70%] with severe PR (≥3 grade) secondary to previous correction of ToF, underwent Melody valve (Medtronic, Minneapolis, MN) implantation, after a pre-stent placement. Full echocardiographic assessment (traditional and deformation analysis) and cardiovascular magnetic resonance evaluation were performed before and at 3 months after the intervention. 'Favorable remodelling' was considered the upper quartile of RV size decrease (>20% in 3 months). After PPVI, indexed RV effective stroke volume increased from 38.4 ± 9.5 to 51.4 ± 10.7 mL/m 2 , (P = 0.005), while RV end-diastolic volume and strain indices decreased (123.1 ± 24.1-101.5 ± 18.3 mL/m 2 , P = 0.005 and -23.5 ± 2.5 to -21 ± 2.5%, P = 0.002, respectively). After inserting pre-PPVI clinical, RV volumetric and deformation parameters in a multiple regression model, only time after last surgical correction causing PR remained as significant regressor of RV remodelling [R 2  = 0.60, beta = 0.387, 95%CI(0.07-0.7), P = 0.019]. Volume reduction and functional improvement were more pronounced in patients treated with PPVI earlier than 7 years after last RV outflow tract (RVOT) correction, reaching close-to-normal values. Early PPVI (<7 years after last RVOT operation) is associated with a more favorable RV reverse remodelling toward normal range and should be considered, before symptoms or RV damage become apparent. © 2017 Wiley Periodicals, Inc. © 2017 Wiley Periodicals, Inc.

The performance of Hancock porcine-valved Dacron conduit for right ventricular outflow tract reconstruction.

PubMed

Belli, Emre; Salihoğlu, Ece; Leobon, Bertrand; Roubertie, François; Ly, Mohammed; Roussin, Régine; Serraf, Alain

2010-01-01

The surgical reconstruction of right ventricle outflow tract (RVOT) often requires the implantation of a valved conduit. Homografts are lacking availability and are associated with limited durability in children. Our experience with the Hancock porcine-valved Dacron (DuPont, Wilmington, DE) conduit (Medtronic, Minneapolis, MN) was retrospectively assessed. Follow-up was studied in 214 survivors who underwent 247 conduit implants between January 1990 and January 2007. Pulmonary atresia/ventricular septal defect was present in 86 (40.2%) and truncus arteriosus in 62 (29%). Conduit implantation was associated with anatomic repair in 136, conduit replacement in 96, and secondary pulmonary valve insertion in 15. Median age at operation was 62.5 months (range, 1 week to 50 years), including 14 neonates (6%). Median conduit size was 17.4 mm because of routine over-sizing. Pulmonary bifurcation patch augmentation was necessary in 26 patients. Periodic echocardiography studies were performed for a median follow-up of 98 months (range, 13 to 142 months). Three (1.4%) late deaths occurred. No conduit-related deaths or complications occurred. Conduit degeneration was associated with increase in valvular gradient. Valve regurgitation was absent or mild. Higher RVOT systolic pressure gradient at discharge did not influence conduit longevity. Conduit reoperation was delayed due to percutaneous balloon dilatation in 14 patients, associated with stenting in 7. Survival with freedom from conduit reoperation was 98% (95% confidence interval [CI], 97% to 100%) at 1 year, 81% (95% CI, 75% to 87%) at 5 years, and 32% (95% CI, 22% to 42%) at 10 years. The Hancock valved conduit is a safe and reliable alternative to homografts. It appears to be appropriate in patients with limited pulmonary vascular bed and high pulmonary artery pressures. Caution is required in neonates because of the rigidity of the Dacron housing. Initial results with secondary percutaneous procedures are encouraging. 2010 The Society of Thoracic Surgeons. Published by Elsevier Inc. All rights reserved.

Divided dosing reduces prednisolone-induced hyperglycaemia and glycaemic variability: a randomized trial after kidney transplantation.

PubMed

Yates, Christopher J; Fourlanos, Spiros; Colman, Peter G; Cohney, Solomon J

2014-03-01

Prednisolone is a major risk factor for hyperglycaemia and new-onset diabetes after transplantation. Uncontrolled observational data suggest that divided dosing may reduce requirements for hypoglycaemic agents. This study aims to compare the glycaemic effects of divided twice daily (BD) and once daily (QD) prednisolone. Twenty-two kidney transplant recipients without diabetes were randomized to BD or QD prednisolone. Three weeks post-transplant, a continuous glucose monitor (iPro2(®) Medtronic) was applied for 5 days with subjects continuing their initial prednisolone regimen (Days 1-2) before crossover to the alternative regimen. Mean glucose, peak glucose, nadir glucose, exposure to hyperglycaemia (glucose ≥7.8 mmol/L) and glycaemic variability were assessed. The mean ± standard deviation (SD) age of subjects was 50 ± 10 years and 77% were male. Median (interquartile range) daily prednisolone dose was 25 (20, 25) mg. BD prednisolone was associated with decreased mean glucose (mean 7.9 ± 1.7 versus 8.1 ± 2.3 mmol/L, P < 0.001), peak glucose [median 10.4 (9.5, 11.4) versus 11.4 (10.3, 13.4) mmol/L, P< 0.001] and exposure to hyperglycaemia [median 25.5 (14.6, 30.3) versus 40.4 (33.2, 51.2) mmol/L/h, P = 0.003]. Median glucose peaked between 14:55-15.05 h with BD and 15:25-15:30 h with QD. Median glycaemic variability scores were decreased with BD: SD (1.1 versus 1.9, P < 0.001), mean amplitude of glycaemic excursion (1.5 versus 2.2, P = 0.001), continuous overlapping net glycaemic action-1 (CONGA-1; 1.0 versus 1.2, P = 0.039), CONGA-2 (1.2 versus 1.4, P = 0.008) and J-index (25 versus 31, P = 0.003). Split prednisolone dosing reduces glycaemic variability and hyperglycaemia early post-kidney transplant.

Accuracy evaluation of a new real-time continuous glucose monitoring algorithm in hypoglycemia.

PubMed

Mahmoudi, Zeinab; Jensen, Morten Hasselstrøm; Dencker Johansen, Mette; Christensen, Toke Folke; Tarnow, Lise; Christiansen, Jens Sandahl; Hejlesen, Ole

2014-10-01

The purpose of this study was to evaluate the performance of a new continuous glucose monitoring (CGM) calibration algorithm and to compare it with the Guardian(®) REAL-Time (RT) (Medtronic Diabetes, Northridge, CA) calibration algorithm in hypoglycemia. CGM data were obtained from 10 type 1 diabetes patients undergoing insulin-induced hypoglycemia. Data were obtained in two separate sessions using the Guardian RT CGM device. Data from the same CGM sensor were calibrated by two different algorithms: the Guardian RT algorithm and a new calibration algorithm. The accuracy of the two algorithms was compared using four performance metrics. The median (mean) of absolute relative deviation in the whole range of plasma glucose was 20.2% (32.1%) for the Guardian RT calibration and 17.4% (25.9%) for the new calibration algorithm. The mean (SD) sample-based sensitivity for the hypoglycemic threshold of 70 mg/dL was 31% (33%) for the Guardian RT algorithm and 70% (33%) for the new algorithm. The mean (SD) sample-based specificity at the same hypoglycemic threshold was 95% (8%) for the Guardian RT algorithm and 90% (16%) for the new calibration algorithm. The sensitivity of the event-based hypoglycemia detection for the hypoglycemic threshold of 70 mg/dL was 61% for the Guardian RT calibration and 89% for the new calibration algorithm. Application of the new calibration caused one false-positive instance for the event-based hypoglycemia detection, whereas the Guardian RT caused no false-positive instances. The overestimation of plasma glucose by CGM was corrected from 33.2 mg/dL in the Guardian RT algorithm to 21.9 mg/dL in the new calibration algorithm. The results suggest that the new algorithm may reduce the inaccuracy of Guardian RT CGM system within the hypoglycemic range; however, data from a larger number of patients are required to compare the clinical reliability of the two algorithms.

Interstitial glucose concentrations and hypoglycemia during 2 days of caloric deficit and sustained exercise: a double-blind, placebo-controlled trial.

PubMed

Smith, Tracey J; Wilson, Marques A; Karl, J Philip; Austin, Krista; Bukhari, Asma; Pasiakos, Stefan M; O'Connor, Kristie L; Lieberman, Harris R

2016-11-01

Military personnel and some athlete populations endure short-term energy deficits from reduced energy intake and/or increased energy expenditure (EE) that may degrade physical and cognitive performance due to severe hypoglycemia (<3.1 mmol/l). The extent to which energy deficits alter normoglycemia (3.9-7.8 mmol/l) in healthy individuals is not known, since prior studies measured glucose infrequently, not continuously. The purpose of this study was to characterize the glycemic response to acute, severe energy deficit compared with fully fed control condition, using continuous glucose monitoring (CGM). For 2 days during a double-blind, placebo-controlled, crossover study, 23 volunteers (17 men/6 women; age: 21.3 ± 3.0 yr; body mass index: 25 ± 3 kg/m) increased habitual daily EE [2,300 ± 450 kcal/day [means ± SD)] by 1,647 ± 345 kcal/day through prescribed exercise (~3 h/day; 40-65% peak O 2 consumption), and consumed diets designed to maintain energy balance (FED) or induce 93% energy deficit (DEF). Interstitial glucose concentrations were measured continuously by CGM (Medtronic Minimed). Interstitial glucose concentrations were 1.0 ± 0.9 mmol/l lower during DEF vs. FED (P < 0.0001). The percentage of time spent in mild (3.1-3.8 mmol/l) hypoglycemia was higher during DEF compared with FED [mean difference = 20.5%; 95% confidence interval (CI): 13.1%, 27.9%; P = 0.04], while time spent in severe (<3.1 mmol/l) hypoglycemia was not different between interventions (mean difference = 4.6%; 95% CI: -0.6%, 9.8%; P = 0.10). Three of 23 participants spontaneously reported symptoms (e.g., nausea) potentially related to hypoglycemia during DEF, and an additional participant reported symptoms during both interventions. These findings suggest that severe hypoglycemia rarely occurs in healthy individuals enduring severe, short-term energy deficit secondary to heavy exercise and inadequate energy intake. Copyright © 2016 the American Physiological Society.

Accuracy and feasibility of three different methods for software-based image fusion in whole-body PET and CT.

PubMed

Putzer, Daniel; Henninger, Benjamin; Kovacs, Peter; Uprimny, Christian; Kendler, Dorota; Jaschke, Werner; Bale, Reto J

2016-06-01

Even as PET/CT provides valuable diagnostic information in a great number of clinical indications, availability of hybrid PET/CT scanners is mainly limited to clinical centers. A software-based image fusion would facilitate combined image reading of CT and PET data sets if hardware image fusion is not available. To analyze the relevance of retrospective image fusion of separately acquired PET and CT data sets, we studied the accuracy, practicability and reproducibility of three different image registration techniques. We evaluated whole-body 18F-FDG-PET and CT data sets of 71 oncologic patients. Images were fused retrospectively using Stealth Station System, Treon (Medtronic Inc., Louisville, CO, USA) equipped with Cranial4 Software. External markers fixed to a vacuum mattress were used as reference for exact repositioning. Registration was repeated using internal anatomic landmarks and Automerge software, assessing accuracy for all three methods, measuring distances of liver representation in CT and PET with reference to a common coordinate system. On first measurement of image fusions with external markers, 53 were successful, 16 feasible and 2 not successful. Using anatomic landmarks, 42 were successful, 26 feasible and 3 not successful. Using Automerge Software only 13 were successful. The mean distance between center points in PET and CT was 7.69±4.96 mm on first, and 7.65±4.2 mm on second measurement. Results with external markers correlate very well and inaccuracies are significantly lower (P<0.001) than results using anatomical landmarks (10.38±6.13 mm and 10.83±6.23 mm). Analysis revealed a significantly faster alignment using external markers (P<0.001). External fiducials in combination with immobilization devices and breathing protocols allow for highly accurate image fusion cost-effectively and significantly less time, posing an attractive alternative for PET/CT interpretation when a hybrid scanner is not available.

Randomized trial of primary PCI with or without routine manual thrombectomy.

PubMed

Jolly, Sanjit S; Cairns, John A; Yusuf, Salim; Meeks, Brandi; Pogue, Janice; Rokoss, Michael J; Kedev, Sasko; Thabane, Lehana; Stankovic, Goran; Moreno, Raul; Gershlick, Anthony; Chowdhary, Saqib; Lavi, Shahar; Niemelä, Kari; Steg, Philippe Gabriel; Bernat, Ivo; Xu, Yawei; Cantor, Warren J; Overgaard, Christopher B; Naber, Christoph K; Cheema, Asim N; Welsh, Robert C; Bertrand, Olivier F; Avezum, Alvaro; Bhindi, Ravinay; Pancholy, Samir; Rao, Sunil V; Natarajan, Madhu K; ten Berg, Jurriën M; Shestakovska, Olga; Gao, Peggy; Widimsky, Petr; Džavík, Vladimír

2015-04-09

During primary percutaneous coronary intervention (PCI), manual thrombectomy may reduce distal embolization and thus improve microvascular perfusion. Small trials have suggested that thrombectomy improves surrogate and clinical outcomes, but a larger trial has reported conflicting results. We randomly assigned 10,732 patients with ST-segment elevation myocardial infarction (STEMI) undergoing primary PCI to a strategy of routine upfront manual thrombectomy versus PCI alone. The primary outcome was a composite of death from cardiovascular causes, recurrent myocardial infarction, cardiogenic shock, or New York Heart Association (NYHA) class IV heart failure within 180 days. The key safety outcome was stroke within 30 days. The primary outcome occurred in 347 of 5033 patients (6.9%) in the thrombectomy group versus 351 of 5030 patients (7.0%) in the PCI-alone group (hazard ratio in the thrombectomy group, 0.99; 95% confidence interval [CI], 0.85 to 1.15; P=0.86). The rates of cardiovascular death (3.1% with thrombectomy vs. 3.5% with PCI alone; hazard ratio, 0.90; 95% CI, 0.73 to 1.12; P=0.34) and the primary outcome plus stent thrombosis or target-vessel revascularization (9.9% vs. 9.8%; hazard ratio, 1.00; 95% CI, 0.89 to 1.14; P=0.95) were also similar. Stroke within 30 days occurred in 33 patients (0.7%) in the thrombectomy group versus 16 patients (0.3%) in the PCI-alone group (hazard ratio, 2.06; 95% CI, 1.13 to 3.75; P=0.02). In patients with STEMI who were undergoing primary PCI, routine manual thrombectomy, as compared with PCI alone, did not reduce the risk of cardiovascular death, recurrent myocardial infarction, cardiogenic shock, or NYHA class IV heart failure within 180 days but was associated with an increased rate of stroke within 30 days. (Funded by Medtronic and the Canadian Institutes of Health Research; TOTAL ClinicalTrials.gov number, NCT01149044.).

Chronic cortical and electromyographic recordings from a fully implantable device: preclinical experience in a nonhuman primate

NASA Astrophysics Data System (ADS)

Ryapolova-Webb, Elena; Afshar, Pedram; Stanslaski, Scott; Denison, Tim; de Hemptinne, Coralie; Bankiewicz, Krystof; Starr, Philip A.

2014-02-01

Objective. Analysis of intra- and perioperatively recorded cortical and basal ganglia local field potentials in human movement disorders has provided great insight into the pathophysiology of diseases such as Parkinson's, dystonia, and essential tremor. However, in order to better understand the network abnormalities and effects of chronic therapeutic stimulation in these disorders, long-term recording from a fully implantable data collection system is needed. Approach. A fully implantable investigational data collection system, the Activa® PC + S neurostimulator (Medtronic, Inc., Minneapolis, MN), has been developed for human use. Here, we tested its utility for extended intracranial recording in the motor system of a nonhuman primate. The system was attached to two quadripolar paddle arrays: one covering sensorimotor cortex, and one covering a proximal forelimb muscle, to study simultaneous cortical field potentials and electromyography during spontaneous transitions from rest to movement. Main results. Over 24 months of recording, movement-related changes in physiologically relevant frequency bands were readily detected, including beta and gamma signals at approximately 2.5 μV/\\sqrtHz and 0.7 μV/\\sqrt{Hz}, respectively. The system architecture allowed for flexible recording configurations and algorithm triggered data recording. In the course of physiological analyses, sensing artifacts were observed (˜1 μVrms stationary tones at fixed frequency), which were mitigated either with post-processing or algorithm design and did not impact the scientific conclusions. Histological examination revealed no underlying tissue damage; however, a fibrous capsule had developed around the paddles, demonstrating a potential mechanism for the observed signal amplitude reduction. Significance. This study establishes the usefulness of this system in measuring chronic brain and muscle signals. Use of this system may potentially be valuable in human trials of chronic brain recording in movement disorders, a next step in the design of closed-loop neurostimulation paradigms.

Cardiac-resynchronization therapy for mild-to-moderate heart failure.

PubMed

Tang, Anthony S L; Wells, George A; Talajic, Mario; Arnold, Malcolm O; Sheldon, Robert; Connolly, Stuart; Hohnloser, Stefan H; Nichol, Graham; Birnie, David H; Sapp, John L; Yee, Raymond; Healey, Jeffrey S; Rouleau, Jean L

2010-12-16

Cardiac-resynchronization therapy (CRT) benefits patients with left ventricular systolic dysfunction and a wide QRS complex. Most of these patients are candidates for an implantable cardioverter-defibrillator (ICD). We evaluated whether adding CRT to an ICD and optimal medical therapy might reduce mortality and morbidity among such patients. We randomly assigned patients with New York Heart Association (NYHA) class II or III heart failure, a left ventricular ejection fraction of 30% or less, and an intrinsic QRS duration of 120 msec or more or a paced QRS duration of 200 msec or more to receive either an ICD alone or an ICD plus CRT. The primary outcome was death from any cause or hospitalization for heart failure. We followed 1798 patients for a mean of 40 months. The primary outcome occurred in 297 of 894 patients (33.2%) in the ICD-CRT group and 364 of 904 patients (40.3%) in the ICD group (hazard ratio in the ICD-CRT group, 0.75; 95% confidence interval [CI], 0.64 to 0.87; P<0.001). In the ICD-CRT group, 186 patients died, as compared with 236 in the ICD group (hazard ratio, 0.75; 95% CI, 0.62 to 0.91; P = 0.003), and 174 patients were hospitalized for heart failure, as compared with 236 in the ICD group (hazard ratio, 0.68; 95% CI, 0.56 to 0.83; P<0.001). However, at 30 days after device implantation, adverse events had occurred in 124 patients in the ICD-CRT group, as compared with 58 in the ICD group (P<0.001). Among patients with NYHA class II or III heart failure, a wide QRS complex, and left ventricular systolic dysfunction, the addition of CRT to an ICD reduced rates of death and hospitalization for heart failure. This improvement was accompanied by more adverse events. (Funded by the Canadian Institutes of Health Research and Medtronic of Canada; ClinicalTrials.gov number, NCT00251251.).

Clinical Outcomes Following Transcatheter Aortic Valve Replacement in Asian Population.

PubMed

Yoon, Sung-Han; Ahn, Jung-Min; Hayashida, Kentaro; Watanabe, Yusuke; Shirai, Shinichi; Kao, Hsien-Li; Yin, Wei-Hsian; Lee, Michael Kang-Yin; Tay, Edgar; Araki, Motoharu; Yamanaka, Futoshi; Arai, Takahide; Lin, Mao-Shin; Park, Jun-Bean; Park, Duk-Woo; Kang, Soo-Jin; Lee, Seung-Whan; Kim, Young-Hak; Lee, Cheol Whan; Park, Seong-Wook; Muramatsu, Toshiya; Hanyu, Michiya; Kozuma, Ken; Kim, Hyo-Soo; Saito, Shigeru; Park, Seung-Jung

2016-05-09

This study describes the characteristics of a real-world Asian patient population treated with transcatheter aortic valve replacement (TAVR) and evaluates their clinical outcomes. No previously reported randomized or observational studies adequately assess the safety and efficacy of TAVR in an Asian population. The Asian TAVR registry is an international multicenter study that enrolled patients with aortic stenosis who underwent TAVR in Asian countries. In total, 848 patients with mean STS score of 5.2 ± 3.8% were enrolled between March 2010 and September 2014 at 11 centers in 5 countries. The Edwards Sapien or Medtronic CoreValve was implanted in 64.7% and 35.3% of patients, respectively. The procedural success rate was 97.5%. The 30-day and 1-year mortality rates were 2.5% and 10.8%, respectively. There was no difference in 1-year mortality between devices (Sapien: 9.4%; CoreValve: 12.2%; log-rank p = 0.40). The rates of stroke, life-threatening bleeding, major vascular complications and acute kidney injury (stage 2 to 3) were 3.8%, 6.4%, 5.0% and 3.3%, respectively. Moderate or severe paravalvular leakage was significantly more common with the CoreValve than Sapien (14.4% vs. 7.3%; p = 0.001). According to the multivariate model, a higher STS score, lower body mass index, New York Heart Association functional class III-IV symptoms, diabetes mellitus, prior cerebrovascular accident, low mean gradient at baseline, and moderate or severe paravalvular leakage were significantly associated with reduced survival. Despite anatomical features of concern, the clinical outcomes of TAVR in our Asian population were favorable in comparison with those of previously published trials and observational studies. (The Asian Transcatheter Aortic Valve Replacement Registry [Asian TAVR]; NCT02308150). Copyright © 2016 American College of Cardiology Foundation. Published by Elsevier Inc. All rights reserved.

Greater diet quality is associated with more optimal glycemic control in a longitudinal study of youth with type 1 diabetes.

PubMed

Nansel, Tonja R; Lipsky, Leah M; Liu, Aiyi

2016-07-01

Despite the centrality of nutrition in the management of type 1 diabetes, the association of diet quality and macronutrient distribution with glycemic control is ambiguous. This study examined longitudinally the association of dietary intake with multiple indicators of glycemic control in youth with type 1 diabetes participating in a behavioral nutrition intervention study. Participants in a randomized clinical trial of a behavioral nutrition intervention [n = 136; mean ± SD age: 12.8 ± 2.6 y; glycated hemoglobin (HbA1c): 8.1% ± 1.0%; 69.1% using an insulin pump] completed 3-d diet records at baseline and months 3, 6, 9, 12, and 18; masked continuous glucose monitoring (CGM) data were obtained concurrently with the use of the Medtronic iPro CGM system. HbA1c was obtained every 3 mo; 1,5-anhydroglucitol was obtained every 6 mo. Linear mixed-effects regression models estimated associations of time-varying dietary intake variables with time-varying glycemic control indicators, controlling for age, height, weight, sex, Tanner stage, diabetes duration, regimen, frequency of blood glucose monitoring, physical activity, and treatment assignment. HbA1c was associated inversely with carbohydrate and natural sugar, and positively with protein and unsaturated fat. 1,5-Anhydroglucitol was associated positively with fiber intake and natural sugar. Greater glycemic control as indicated by ≥1 CGM variable was associated with higher Healthy Eating Index-2005, whole plant food density, fiber, carbohydrate, and natural sugar and lower glycemic index and unsaturated fat. Both overall diet quality and macronutrient distribution were associated with more optimal glycemic control. Associations were more consistent for CGM variables obtained concurrently with dietary intake than for biomarkers of longer-term glycemic control. These findings suggest that glycemic control may be improved by increasing intake of high-fiber, low glycemic-index, carbohydrate-containing foods. This trial was registered at clinicaltrials.gov as NCT00999375. © 2016 American Society for Nutrition.

The Mosaic bioprosthesis in the aortic position: 17 years' results.

PubMed

Gansera, Brigitte; Hapfelmeier, Alexander; Brandl, Kristina; Spiliopoulos, Kyriakos; Gundling, Felix; Eichinger, Walter

2014-02-01

The Mosaic bioprosthesis (Medtronic Inc., Minneapolis, Minnesota, United States), a stented porcine aortic valve, combines glutaraldehyde fixation with zero-pressure, root-pressure techniques and antimineralization treatment with amino-oleic acid for improved hemodynamics and tissue durability. The first device has been implanted worldwide at the authors' institution in September 1993. The aim of the present study was to collect mid- to long-term data of the prosthesis. A total of 272 patients (124 males and 148 females) underwent isolated aortic valve replacement with the Mosaic bioprosthesis between September 1993 and August 2007. Median age at implant was 76.8 years (range, 31.3 to 90.7). Median follow-up was 12.0 years (range, 0 to 17.2 years); follow-up was complete for 223 (82%) patients. Early mortality (30 days) was 4% (12 patients). Overall survival at 5, 10, 15, and 17 years was 68.6% ± 3.1%, 36.4% ± 3.3%, 17.1% ± 3.6%, and 10.7% ± 4.3%, respectively. Eleven late deaths (5%) were cardiac related. There were 24 thromboembolic events, 1 hemorrhagic, and 6 reoperations/explants. At a median follow-up of 12 years, freedom from any cause of death was 27.0% ± 3.2% acting as a competing risk for the incidence of thromboembolic events (16.4% ± 3.5%), hemorrhage (0.5% ± 0.5%), and reoperation/explant (4.1% ± 1.8%). Two redos were due to structural valve deterioration (SVD), two for nonstructural dysfunction (paravalvular leakage), one for thrombosed prosthesis, and one for endocarditis. Performance and late outcome of the Mosaic bioprosthesis was satisfactory during 17 years after clinical introduction. The Mosaic bioprosthesis showed low incidence of SVD or need for reoperation in the long term. Georg Thieme Verlag KG Stuttgart · New York.

Developments in parallel grafts for aortic arch lesions.

PubMed

Kolvenbach, Ralf R; Rabin, Asaf; Karmeli, Ron; Alpaslan, Alper; Schwierz, Elizabeth

2016-06-01

Due to the shortage of commercially available off the shelf aortic arch grafts since the last years parallel grafts or chimney grafts have played an increasing role in the treatment of patients with aortic arch lesions. Although there are still issues with type endoleaks and gutters between the chimney graft and the aortic stent-graft remaining. We report our results with the Medtronic thoracic graft in combination with long self-expanding parallel grafts, to ensure an overlapping zone of more than 7 cm between the different grafts. Alternatively, sandwich configurations are used where a direct contact between the parallel graft and the aortic wall is avoided. We have placed a total of 65 parallel grafts into supra-aortic branches. In 21 cases chimney grafts were placed into the carotid artery, in most cases into the left common carotid artery. In 36 cases chimney grafts were placed into left subclavian artery. A maximum number of 4 parallel grafts were placed for total endovascular debranching. In addition, in 8 patients a parallel graft had to be placed into the innominate artery. There was a patency of 69% for all subclavian artery chimney grafts versus 73% for carotid artery parallel grafts. Of note is a stroke rate of 5.2% in all these cases. Only 2 of the patients with an occluded left subclavian artery chimney graft required a bypass procedure for arm claudication or ischemia. We had a primary type I endoleak rate of 28%. In almost 25% secondary interventions were required mainly to treat type I leaks, in those cases where the leak did not resolve spontaneously. The overall mortality rate was 3.5%. The results of parallel graft in the aortic arch are promising, but of major concern is still the high rate of type I endoleaks as well as the neurological complication rate, most probably due to catheter manipulation in patients with severe atherosclerotic arch lesions.

Multicenter, randomized study to optimize bowel preparation for colon capsule endoscopy

PubMed Central

Kastenberg, David; Jr, Wilmot C Burch; Romeo, David P; Kashyap, Pankaj K; Pound, David C; Papageorgiou, Neophytos; Sainz, Ignacio Fernández-Urien; Sokach, Carly E; Rex, Douglas K

2017-01-01

AIM To assess the cleansing efficacy and safety of a new Colon capsule endoscopy (CCE) bowel preparation regimen. METHODS This was a multicenter, prospective, randomized, controlled study comparing two CCE regimens. Subjects were asymptomatic and average risk for colorectal cancer. The second generation CCE system (PillCam® COLON 2; Medtronic, Yoqneam, Israel) was utilized. Preparation regimens differed in the 1st and 2nd boosts with the Study regimen using oral sulfate solution (89 mL) with diatrizoate meglumine and diatrizoate sodium solution (“diatrizoate solution”) (boost 1 = 60 mL, boost 2 = 30 mL) and the Control regimen oral sulfate solution (89 mL) alone. The primary outcome was overall and segmental colon cleansing. Secondary outcomes included safety, polyp detection, colonic transit, CCE completion and capsule excretion ≤ 12 h. RESULTS Both regimens had similar cleansing efficacy for the whole colon (Adequate: Study = 75.9%, Control = 77.3%; P = 0.88) and individual segments. In the Study group, CCE completion was superior (Study = 90.9%, Control = 76.9%; P = 0.048) and colonic transit was more often < 40 min (Study = 21.8%, Control = 4%; P = 0.0073). More Study regimen subjects experienced adverse events (Study = 19.4%, Control = 3.4%; P = 0.0061), and this difference did not appear related to diatrizoate solution. Adverse events were primarily gastrointestinal in nature and no serious adverse events related either to the bowel preparation regimen or the capsule were observed. There was a trend toward higher polyp detection with the Study regimen, but this did not achieve statistical significance for any size category. Mean transit time through the entire gastrointestinal tract, from ingestion to excretion, was shorter with the Study regimen while mean colonic transit times were similar for both study groups. CONCLUSION A CCE bowel preparation regimen using oral sulfate solution and diatrizoate solution as a boost agent is effective, safe, and achieved superior CCE completion. PMID:29358870

[Endovascular radiofrequency denervation of renal arteries as an innovation method of treatment of refractory arterial hypertension. First experience in Russia].

PubMed

Danilov, N M; Matchin, Iu G; Chazova, I E

2012-01-01

Excessive activation of the sympathetic nervous system forms the basis of pathogenesis of essential arterial hypertension (AH). The present work was aimed at evaluating efficacy and safety of endovascular radiofrequency denervation of renal arteries in patients with AH refractory AH based on the initial first experience in with using this methodology in the Russian Federation. The interventions were carried out on December 14-15th, 2011 in the first five patients presenting with AH refractory to antihypertensive therapy consisting of three and more drugs in therapeutic doses, one of which was a diuretic. The selection criteria were systolic arterial pressure (SAP) ≥160 mm Hg or ≥150 mm Hg in the presence of type 2 diabetes mellitus. The obligatory conditions for selection were the preserved renal function [glomerular filtration rate (GFR) ≥45 ml/min] and the absence of the secondary form of AH. The procedure of denervation was performed in the conditions of roentgen-operating room using special Medtronic Ardian Simplicity Catheter System™. In all cases we managed to perform bilateral denervation of renal arteries with the radiofrequency effect in not less than 4 zones of each of vessels. Efficacy of each of the effect was registered with due regard for reaching certain temperature and values of impedance. The interventions were not accompanied by the development of any complications either in the area of manipulations or the site of puncture. Neither were there any complications from the side of the cardiovascular or excretory systems of the body. Diurnal monitoring of AP (DMAP) registered a significant decrease in SAP averagely from 174±12 to 145±10 mm Hg three days after the intervention. A persistent antihypertensive effect was confirmed by the DMAP findings one month after denervation - the SAP level averagely amounted to 131±6 mm Hg. Endovascular radiofrequency denervation of renal arteries is a safe and efficient method of treatment of AH resistant to multicomponent antihypertensive therapy.

Technical pitfalls and tips for the valve-in-valve procedure

PubMed Central

2017-01-01

Transcatheter aortic valve implantation (TAVI) has emerged as a viable treatment modality for patients with severe aortic valve stenosis and multiple co-morbidities. More recent indications include the use of transcatheter heart valves (THV) to treat degenerated bioprosthetic surgical heart valves (SHV), which are failing due to stenosis or regurgitation. Valve-in-valve (VIV) procedures in the aortic position have been performed with a variety of THV devices, although the balloon-expandable SAPIEN valve platform (Edwards Lifesciences Ltd, Irvine, CA, USA) and self-expandable CoreValve platform (Medtronic Inc., MN, USA) have been used in majority of the patients. VIV treatment is appealing as it is less invasive than conventional surgery but optimal patient selection is vital to avoid complications such as malposition, residual high gradients and coronary obstruction. To minimize the risk of complications, thorough procedural planning is critical. The first step is identification of the degenerated SHV, including its model, size, fluoroscopic appearance. Although label size and stent internal diameter (ID) are provided by the manufacturer, it is important to note the true ID. The true ID is the ID of a SHV after the leaflets are mounted and helps determine the optimal size of THV. The second step is to determine the type and size of the THV. Although this is determined in the majority of the cases by user preference, in certain situations one THV may be more suitable than another. As the procedure is performed under fluoroscopy, the third step is to become familiarized with the fluoroscopic appearance of both the SHV and THV. This helps to determine the landmarks for optimal positioning, which in turn determines the gradients and fixation. The fourth step is to assess the risk of coronary obstruction. This is performed with either aortic root angiography or ECG-gated computerised tomography (CT). Finally, the route of approach must be carefully planned. Once these aspects are addressed, the procedure can be performed efficiently with a low risk of complications. PMID:29062752

Is valve choice a significant determinant of paravalular leak post-transcatheter aortic valve implantation? A systematic review and meta-analysis.

PubMed

O'Sullivan, Katie E; Gough, Aideen; Segurado, Ricardo; Barry, Mitchel; Sugrue, Declan; Hurley, John

2014-05-01

Paravalvular regurgitation (PVR) following transcatheter aortic valve implantation (TAVI) is associated with poor survival. The two main valve delivery systems used to date differ significantly in both structure and deployment technique. The primary objective of this study was to perform a systematic review and meta-analysis of studies identifying PVR in patients post-TAVI using Medtronic CoreValve (MCV) and Edward Sapien (ES) valves in order to identify whether a significant difference exists between valve types. The secondary objective was to identify additional factors predisposing to PVR to provide an overview of the other associated considerations. A systematic review and meta-analysis of the current literature to identify PVR rate in patients with MCV and ES valves was performed. We also sought to examine other factors predisposing to PVR. A total of 5910 patients were identified from 9 studies. PVR rates for MCV and ES were analysed. MCV was associated with a higher PVR rate of 15.75% [95% confidence interval (CI) 12.48-19.32] compared with ES 3.93% [95% CI 1.05-8.38]. We separately reviewed predisposing factors associated with PVR. A formal comparison of the MCV and ES valve leakage rates by mixed-effects meta-regression with a fixed-effect moderator variable for valve type (MCV or ES) suggested a statistically significant difference in leakage rate between the two valve types (P = 0.0002). Unfavourable anatomical and pathological factors as well as valve choice have an impact on rates of PVR. Additionally, certain anatomical features dictate valve choice. A direct comparison of all the predisposing factors at this time is not possible and will require prospective multivariate analysis. There is, however, a significant difference in the PVR rates between valves based on the published observational data available to date. The ES valve associated with a lower incidence of PVR overall; therefore, we conclude that valve choice is indeed a significant determinant of PVR post-TAVI.

Direct comparison of coronary bare metal vs. drug-eluting stents: same platform, different mechanics?

PubMed

Schmidt, Wolfram; Lanzer, Peter; Behrens, Peter; Brandt-Wunderlich, Christoph; Öner, Alper; Ince, Hüseyin; Schmitz, Klaus-Peter; Grabow, Niels

2018-01-08

Drug-eluting stents (DES) compared to bare metal stents (BMS) have shown superior clinical performance, but are considered less suitable in complex cases. Most studies do not distinguish between DES and BMS with respect to their mechanical performance. The objective was to obtain mechanical parameters for direct comparison of BMS and DES. In vitro bench tests evaluated crimped stent profiles, crossability in stenosis models, elastic recoil, bending stiffness (crimped and expanded), and scaffolding properties. The study included five pairs of BMS and DES each with the same stent platforms (all n = 5; PRO-Kinetic Energy, Orsiro: BIOTRONIK AG, Bülach, Switzerland; MULTI-LINK 8, XIENCE Xpedition: Abbott Vascular, Temecula, CA; REBEL Monorail, Promus PREMIER, Boston Scientific, Marlborough, MA; Integrity, Resolute Integrity, Medtronic, Minneapolis, MN; Kaname, Ultimaster: Terumo Corporation, Tokyo, Japan). Statistical analysis used pooled variance t tests for pairwise comparison of BMS with DES. Crimped profiles in BMS groups ranged from 0.97 ± 0.01 mm (PRO-Kinetic Energy) to 1.13 ± 0.01 mm (Kaname) and in DES groups from 1.02 ± 0.01 mm (Orsiro) to 1.13 ± 0.01 mm (Ultimaster). Crossability was best for low profile stent systems. Elastic recoil ranged from 4.07 ± 0.22% (Orsiro) to 5.87 ± 0.54% (REBEL Monorail) including both BMS and DES. The bending stiffness of crimped and expanded stents showed no systematic differences between BMS and DES neither did the scaffolding. Based on in vitro measurements BMS appear superior to DES in some aspects of mechanical performance, yet the differences are small and not class uniform. The data provide assistance in selecting the optimal system for treatment and assessment of new generations of bioresorbable scaffolds. not applicable.

Randomized comparison of renal denervation versus intensified pharmacotherapy including spironolactone in true-resistant hypertension: six-month results from the Prague-15 study.

PubMed

Rosa, Ján; Widimský, Petr; Toušek, Petr; Petrák, Ondřej; Čurila, Karol; Waldauf, Petr; Bednář, František; Zelinka, Tomáš; Holaj, Robert; Štrauch, Branislav; Šomlóová, Zuzana; Táborský, Miloš; Václavík, Jan; Kociánová, Eva; Branny, Marian; Nykl, Igor; Jiravský, Otakar; Widimský, Jiří

2015-02-01

This prospective, randomized, open-label multicenter trial evaluated the efficacy of catheter-based renal denervation (Symplicity, Medtronic) versus intensified pharmacological treatment including spironolactone (if tolerated) in patients with true-resistant hypertension. This was confirmed by 24-hour ambulatory blood pressure monitoring after excluding secondary hypertension and confirmation of adherence to therapy by measurement of plasma antihypertensive drug levels before enrollment. One-hundred six patients were randomized to renal denervation (n=52), or intensified pharmacological treatment (n=54) with baseline systolic blood pressure of 159±17 and 155±17 mm Hg and average number of drugs 5.1 and 5.4, respectively. A significant reduction in 24-hour average systolic blood pressure after 6 months (-8.6 [95% cofidence interval: -11.8, -5.3] mm Hg; P<0.001 in renal denervation versus -8.1 [95% cofidence interval: -12.7, -3.4] mm Hg; P=0.001 in pharmacological group) was observed, which was comparable in both groups. Similarly, a significant reduction in systolic office blood pressure (-12.4 [95% cofidence interval: -17.0, -7.8] mm Hg; P<0.001 in renal denervation versus -14.3 [95% cofidence interval: -19.7, -8.9] mm Hg; P<0.001 in pharmacological group) was present. Between-group differences in change were not significant. The average number of antihypertensive drugs used after 6 months was significantly higher in the pharmacological group (+0.3 drugs; P<0.001). A significant increase in serum creatinine and a parallel decrease of creatinine clearance were observed in the pharmacological group; between-group difference were borderline significant. The 6-month results of this study confirmed the safety of renal denervation. In conclusion, renal denervation achieved reduction of blood pressure comparable with intensified pharmacotherapy. © 2014 American Heart Association, Inc.

Usefulness of intraoperative ultra low-field magnetic resonance imaging in glioma surgery.

PubMed

Senft, Christian; Seifert, Volker; Hermann, Elvis; Franz, Kea; Gasser, Thomas

2008-10-01

The aim of this study was to demonstrate the usefulness of a mobile, intraoperative 0.15-T magnetic resonance imaging (MRI) scanner in glioma surgery. We analyzed our prospectively collected database of patients with glial tumors who underwent tumor resection with the use of an intraoperative ultra low-field MRI scanner (PoleStar N-20; Odin Medical Technologies, Yokneam, Israel/Medtronic, Louisville, CO). Sixty-three patients with World Health Organization Grade II to IV tumors were included in the study. All patients were subjected to postoperative 1.5-T imaging to confirm the extent of resection. Intraoperative image quality was sufficient for navigation and resection control in both high- and low-grade tumors. Primarily enhancing tumors were best detected on T1-weighted imaging, whereas fluid-attenuated inversion recovery sequences proved best for nonenhancing tumors. Intraoperative resection control led to further tumor resection in 12 (28.6%) of 42 patients with contrast-enhancing tumors and in 10 (47.6%) of 21 patients with noncontrast-enhancing tumors. In contrast-enhancing tumors, further resection led to an increased rate of complete tumor resection (71.2 versus 52.4%), and the surgical goal of gross total removal or subtotal resection was achieved in all cases (100.0%). In patients with noncontrast-enhancing tumors, the surgical goal was achieved in 19 (90.5%) of 21 cases, as intraoperative MRI findings were inconsistent with postoperative high-field imaging in 2 cases. The use of the PoleStar N-20 intraoperative ultra low-field MRI scanner helps to evaluate the extent of resection in glioma surgery. Further tumor resection after intraoperative scanning leads to an increased rate of complete tumor resection, especially in patients with contrast-enhancing tumors. However, in noncontrast- enhancing tumors, the intraoperative visualization of a complete resection seems less specific, when compared with postoperative 1.5-T MRI.

Sensor Life and Overnight Closed Loop: A Randomized Clinical Trial.

PubMed

Tauschmann, Martin; Allen, Janet M; Wilinska, Malgorzata E; Ruan, Yue; Thabit, Hood; Acerini, Carlo L; Dunger, David B; Hovorka, Roman

2017-05-01

Closed-loop (CL) systems direct insulin delivery based on continuous glucose monitor (CGM) sensor values. CGM accuracy varies with sensor life, being least accurate on day 1 of sensor insertion. We evaluated the effect of sensor life (enhanced Enlite, Medtronic MiniMed, Northridge, CA) on overnight CL. In an open-label, randomized, 2-period, inpatient crossover pilot study, 12 adolescents on insulin pump (age 16.7 ± 1.9 years; HbA1c 66 ± 10 mmol/mol) attended a clinical research facility on 2 overnight occasions. In random order, participants received CL on day 1 or on day 3-4 after sensor insertion. During both periods, glucose was automatically controlled by a model predictive control algorithm informed by sensor glucose. Plasma glucose was measured every 30 to 60 min. During overnight CL (22:30 to 07:30), the proportion of time with plasma glucose readings in the target range (3.9-8.0 mmol/l, primary endpoint) when initiated on day 1 of sensor insertion vs day 3-4 were comparable (58 ± 32% day 1 vs 56 ± 36% day 3-4; P = .34), and there were no significant differences between interventions in terms of mean plasma glucose ( P = .26), percentage time above 8.0 mmol/l ( P = .49), and time spent below 3.9 mmol/l ( P = .93). Sensor accuracy varied with sensor life (mean absolute relative difference 19.8 ± 15.0% on day 1 and 13.7 ± 10.2% on day 3 to 4). Sensor glucose tended to under-read plasma glucose inflating benefits of CL on glucose control. In spite of differences in sensor accuracy, overnight CL glucose control informed by sensor glucose on day 1 or day 3-4 after sensor insertion was comparable. The model predictive controller appears to mitigate against sensor inaccuracies.

Comparison of anti-siphon devices-how do they affect CSF dynamics in supine and upright posture?

PubMed

Gehlen, Manuel; Eklund, Anders; Kurtcuoglu, Vartan; Malm, Jan; Schmid Daners, Marianne

2017-08-01

Three different types of anti-siphon devices (ASDs) have been developed to counteract siphoning-induced overdrainage in upright posture. However, it is not known how the different ASDs affect CSF dynamics under the complex pressure environment seen in clinic due to postural changes. We investigated which ASDs can avoid overdrainage in upright posture best without leading to CSF accumulation. Three shunts each of the types Codman Hakim with SiphonGuard (flow-regulated), Miethke miniNAV with proSA (gravitational), and Medtronic Delta (membrane controlled) were tested. The shunts were compared on a novel in vitro setup that actively emulates the physiology of a shunted patient. This testing method allows determining the CSF drainage rates, resulting CSF volume, and intracranial pressure in the supine, sitting, and standing posture. The flow-regulated ASDs avoided increased drainage by closing their primary flow path when drainage exceeded 1.39 ± 0.42 mL/min. However, with intraperitoneal pressure increased in standing posture, we observed reopening of the ASD in 3 out of 18 experiment repetitions. The adjustable gravitational ASDs allow independent opening pressures in horizontal and vertical orientation, but they did not provide constant drainage in upright posture (0.37 ± 0.03 mL/min and 0.26 ± 0.03 mL/min in sitting and standing posture, respectively). Consequently, adaptation to the individual patient is critical. The membrane-controlled ASDs stopped drainage in upright posture. This eliminates the risk of overdrainage, but leads to CSF accumulation up to the volume observed without shunting when the patient is upright. While all tested ASDs reduced overdrainage, their actual performance will depend on a patient's specific needs because of the large variation in the way the ASDs influence CSF dynamics: while the flow-regulated shunts provide continuous drainage in upright posture, the gravitational ASDs allow and require additional adaptation, and the membrane-controlled ASDs show robust siphon prevention by a total stop of drainage.

Incidence of ineffective safety margin testing (<10 J) and efficacy of routine subcutaneous array insertion during implantable cardioverter defibrillator implantation.

PubMed

Ohlow, Marc-Alexander; Roos, Marcus; Lauer, Bernward; Geller, J Christoph

2016-01-01

The purpose of this study was to assess (1) the incidence of safety margin testing <10 J (SMT) and (2) the efficacy/safety of routinely adding a subcutaneous array (SQA) (Medtronic 6996SQ) for these patients. Patients with SMT smaller than a 10-J safety margin from maximum output were considered to have very high readings and underwent SQA insertion. These patients were compared with the rest of the patients who had acceptable SMT (≥10 J). A total of 616 patients underwent ICD implantation during the analysis period. Of those, 16 (2.6%) had SMT <10 J. By univariate analysis, younger age, and non-ischemic cardiomyopathy, were all significant predictors of SMT <10 J (p < 0.05). In all 16 cases, other methods to improve SMT prior to array insertion were attempted but failed for all patients: reversing shock polarity (n = 15), removing the superior vena cava coil (n = 14), reprogramming shock waveform (n = 9), and repositioning right ventricular lead (n = 9). Addition of the SQA successfully increased SMT to within safety margin for all patients (32 ± 2 versus 21 ± 3 J; p < 0.001). Follow-up (mean 48.1 ± 21 months) was available for all patients with SQA, only 2 cases with inappropriate shocks due to atrial fibrillation had to be noted. None of the patients experienced complications due to SQA implantation. SMT <10 J occur in about 2.6% of patients undergoing ICD implantation. SQA insertion corrects this problem without procedural/mid-term complications. Copyright © 2016 Indian Heart Rhythm Society. Production and hosting by Elsevier B.V. All rights reserved.

Best practices in early phase medical device development: Engineering, prototyping, and the beginnings of a quality management system.

PubMed

Fearis, Kristy; Petrie, Aidan

2017-03-01

Kristy Fearis is the founder and president of KPConsulting. She has held various positions in the medical device and research industry. She has led programs for medical industry leaders Medtronic, Edward Lifesciences, and Kimberly-Clark Healthcare to develop and commercialize Class II and III devices. Although a true quality management systems specialist at heart, Kristy has a passion for effectively and efficiently applying quality systems principles to early stage development to maximize benefit while minimizing impact on resources and time to market. Kristy works with both precommercial and commercial companies to build and implement quality systems that are "right sized" and support both an effective business model and high product quality. Aidan Petrie is the cofounder and chief innovation officer of Ximedica. Aidan drives innovation in Ximedica's core markets of medical device development and consumer healthcare. With a focus on human-centered design, usability, technical innovation and industrial design, Aidan has helped bring hundreds of products to market. Ranging from simple drug compliance aids to wearable therapeutics, home monitoring products, and complex surgical systems, Aidan challenges his teams to rethink the role design plays in the success of each product. Covering topics around usability, sensor and wearable technology, and current trends in medical design and development, Aidan is a sought-after industry speaker and widely published author. In addition to his role at Ximedica, Aidan advises multiple startups in the healthcare space and has interests in a number of related companies. He sits on the Board of MassArt and teaches and lectures at the Rhode Island School of Design, Massachusetts Institute of Technology, the Harvard iLab, and others. Aidan holds an undergraduate degree from Central St Martins in product design/engineering and a Masters in industrial design from the Rhode Island School of Design. Copyright © 2016 Elsevier Inc. All rights reserved.

Total Ossicular Replacement Prosthesis: A New Fat Interposition Technique.

PubMed

Saliba, Issam; Sabbah, Valérie; Poirier, Jackie Bibeau

2018-01-01

To compare audiometric results between the standard total ossicular replacement prosthesis (TORP-S) and a new fat interposition total ossicular replacement prosthesis (TORP-F) in pediatric and adult patients and to assess the complication and the undesirable outcome. This is a retrospective study. This study included 104 patients who had undergone titanium implants with TORP-F and 54 patients who had undergone the procedure with TORP-S between 2008 and 2013 in our tertiary care centers. The new technique consists of interposing a fat graft between the 4 legs of the universal titanium prosthesis (Medtronic Xomed Inc, Jacksonville, FL, USA) to provide a more stable TORP in the ovale window niche. Normally, this prosthesis is designed to fit on the stapes' head as a partial ossicular replacement prosthesis. The postoperative air-bone gap less than 25 dB for the combined cohort was 69.2% and 41.7% for the TORP-F and the TORP-S groups, respectively. The mean follow-up was 17 months postoperatively. By stratifying data, the pediatric cohort shows 56.5% in the TORP-F group (n = 52) compared with 40% in the TORP-S group (n = 29). However, the adult cohort shows 79.3% in the TORP-F group (n = 52) compared with 43.75% in the TORP-S group (n = 25). These improvements in hearing were statistically significant. There were no statistically significant differences in the speech discrimination scores. The only undesirable outcome that was statistically different between the 2 groups was the prosthesis displacement: 7% in the TORP-F group compared with 19% in the TORP-S group ( P  = .03). The interposition of a fat graft between the legs of the titanium implants (TORP-F) provides superior hearing results compared with a standard procedure (TORP-S) in pediatric and adult populations because of its better stability in the oval window niche.

Total Ossicular Replacement Prosthesis: A New Fat Interposition Technique

PubMed Central

Saliba, Issam; Sabbah, Valérie; Poirier, Jackie Bibeau

2018-01-01

Objective: To compare audiometric results between the standard total ossicular replacement prosthesis (TORP-S) and a new fat interposition total ossicular replacement prosthesis (TORP-F) in pediatric and adult patients and to assess the complication and the undesirable outcome. Study design: This is a retrospective study. Methods: This study included 104 patients who had undergone titanium implants with TORP-F and 54 patients who had undergone the procedure with TORP-S between 2008 and 2013 in our tertiary care centers. The new technique consists of interposing a fat graft between the 4 legs of the universal titanium prosthesis (Medtronic Xomed Inc, Jacksonville, FL, USA) to provide a more stable TORP in the ovale window niche. Normally, this prosthesis is designed to fit on the stapes’ head as a partial ossicular replacement prosthesis. Results: The postoperative air-bone gap less than 25 dB for the combined cohort was 69.2% and 41.7% for the TORP-F and the TORP-S groups, respectively. The mean follow-up was 17 months postoperatively. By stratifying data, the pediatric cohort shows 56.5% in the TORP-F group (n = 52) compared with 40% in the TORP-S group (n = 29). However, the adult cohort shows 79.3% in the TORP-F group (n = 52) compared with 43.75% in the TORP-S group (n = 25). These improvements in hearing were statistically significant. There were no statistically significant differences in the speech discrimination scores. The only undesirable outcome that was statistically different between the 2 groups was the prosthesis displacement: 7% in the TORP-F group compared with 19% in the TORP-S group (P = .03). Conclusions: The interposition of a fat graft between the legs of the titanium implants (TORP-F) provides superior hearing results compared with a standard procedure (TORP-S) in pediatric and adult populations because of its better stability in the oval window niche. PMID:29326537

Analysis of insulin pump settings in children and adolescents with type 1 diabetes mellitus.

PubMed

Lau, Yu Ning; Korula, Sophy; Chan, Albert K; Heels, Kristine; Krass, Ines; Ambler, Geoffrey

2016-08-01

To characterize current insulin pump settings used in young patients with type 1 diabetes mellitus (T1DM) and to assess their relationship to glycemic control. This retrospective study included patients aged <18 yr old with T1DM >1 yr using a Medtronic pump device. Pump data including number of blood glucose (BG) tests per day, basal and bolus insulin parameters, carbohydrate ratio (CR), and insulin sensitivity factors (ISFs) were averaged over 14 d for statistical analyses. Anthropometric data and recent glycosylated hemoglobin A1c (HbA1c) were recorded. A total of 292 patients (144 males and 148 females) were included in the study. Participants had a median age (interquartile range, IQR) of 12.9 yr (10.0-15.1 yr) and pump duration of 2.8 yr (1.5-4.2 yr). No significant differences in median HbA1c (IQR) were observed in preschool [n = 14; HbA1c 7.8% (7.3-8.3%)], prepubertal [n = 105; HbA1c 8.1% (7.7-8.9%)], and adolescent subjects [n = 173; HbA1c 8.4% (7.7-9.0%)]. Adolescents took significantly fewer boluses and BG tests per day compared with younger children (p < 0.05). Age-specific diurnal variation in basal insulin delivery was noted. Additionally, stronger carbohydrate cover and weaker corrections were used in real-life compared with theoretical 500 and 100 rules, respectively. Lower HbA1c was associated with higher number of daily boluses, greater number of BG tests per day, lower average CR/500 rule ratio, and higher average ISF/100 rule ratio adjusted for age (R(2) = 0.22; p < 0.01). Insulin pump therapy requires continuous adjustments and glycemic targets are achieved by a minority. We believe this is the first study in pediatric cohort looking at association between CR and ISF with glycemic control. © 2015 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Transcatheter aortic valve replacement using a self-expanding bioprosthesis in patients with severe aortic stenosis at extreme risk for surgery.

PubMed

Popma, Jeffrey J; Adams, David H; Reardon, Michael J; Yakubov, Steven J; Kleiman, Neal S; Heimansohn, David; Hermiller, James; Hughes, G Chad; Harrison, J Kevin; Coselli, Joseph; Diez, Jose; Kafi, Ali; Schreiber, Theodore; Gleason, Thomas G; Conte, John; Buchbinder, Maurice; Deeb, G Michael; Carabello, Blasé; Serruys, Patrick W; Chenoweth, Sharla; Oh, Jae K

2014-05-20

This study sought to evaluate the safety and efficacy of the CoreValve transcatheter heart valve (THV) for the treatment of severe aortic stenosis in patients at extreme risk for surgery. Untreated severe aortic stenosis is a progressive disease with a poor prognosis. Transcatheter aortic valve replacement (TAVR) with a self-expanding bioprosthesis is a potentially effective therapy. We performed a prospective, multicenter, nonrandomized investigation evaluating the safety and efficacy of self-expanding TAVR in patients with symptomatic severe aortic stenosis with prohibitive risks for surgery. The primary endpoint was a composite of all-cause mortality or major stroke at 12 months, which was compared with a pre-specified objective performance goal (OPG). A total of 41 sites in the United States recruited 506 patients, of whom 489 underwent attempted treatment with the CoreValve THV. The rate of all-cause mortality or major stroke at 12 months was 26.0% (upper 2-sided 95% confidence bound: 29.9%) versus 43.0% with the OPG (p < 0.0001). Individual 30-day and 12-month events included all-cause mortality (8.4% and 24.3%, respectively) and major stroke (2.3% and 4.3%, respectively). Procedural events at 30 days included life-threatening/disabling bleeding (12.7%), major vascular complications (8.2%), and need for permanent pacemaker placement (21.6%). The frequency of moderate or severe paravalvular aortic regurgitation was lower 12 months after self-expanding TAVR (4.2%) than at discharge (10.7%; p = 0.004 for paired analysis). TAVR with a self-expanding bioprosthesis was safe and effective in patients with symptomatic severe aortic stenosis at prohibitive risk for surgical valve replacement. (Safety and Efficacy Study of the Medtronic CoreValve System in the Treatment of Symptomatic Severe Aortic Stenosis in High Risk and Very High Risk Subjects Who Need Aortic Valve Replacement; NCT01240902). Copyright © 2014 American College of Cardiology Foundation. Published by Elsevier Inc. All rights reserved.

Taking a Closer Look--Continuous Glucose Monitoring in Non-Critically Ill Hospitalized Patients with Type 2 Diabetes Mellitus Under Basal-Bolus Insulin Therapy.

PubMed

Schaupp, Lukas; Donsa, Klaus; Neubauer, Katharina M; Mader, Julia K; Aberer, Felix; Höll, Bernhard; Spat, Stephan; Augustin, Thomas; Beck, Peter; Pieber, Thomas R; Plank, Johannes

2015-09-01

Inpatient glucose management is based on four daily capillary blood glucose (BG) measurements. The aim was to test the capability of continuous glucose monitoring (CGM) for assessing the clinical impact and safety of basal-bolus insulin therapy in non-critically ill hospitalized patients with type 2 diabetes mellitus (T2DM). Eighty-four patients with T2DM (age, 68±10 years; glycosylated hemoglobin, 72±28 mmol/mol; body mass index, 31±7 kg/m(2)) were treated with basal-bolus insulin. CGM was performed with the iPro(®)2 system (Medtronic MiniMed, Northridge, CA) and calibrated retrospectively. A remarkable consistency between CGM and BG measurements and therapy improvement was shown over the study period of 501 patient-days. The number of CGM and BG measurements (CGM/BG) in the range from 3.9-10 mmol/L increased from 67.7%/67.2% (on Day 1) to 77.5%/78.6% (on the last day) (P<0.04). The number of low glycemic episodes (3.3 to <3.9 mmol/L) during nighttime detected by CGM was 15-fold higher, and the number of episodes >13.9 mmol/L detected by CGM during night was 12.5-fold higher than the values from the BG measurements. Ninety-nine percent of data points were in the clinically accurate or acceptable Clarke Error Grid Zones A+B, and the relative numbers of correctly identified episodes of <3.9 and >13.9 mmol/L detected by CGM (sensitivity) were 47.3% and 81.5%, respectively. Our data exhibit a good agreement between overall CGM and BG measurements, but there were a high number of missed hypo- and hyperglycemic episodes with BG measurements, particularly during nighttime. Overall assessment of glycemic control using CGM is feasible, whereas the use of CGM for individualized therapy decisions needs further improvement.

Randomised clinical trial of cryoballoon versus irrigated radio frequency catheter ablation for atrial fibrillation-the effect of double short versus standard exposure cryoablation duration during pulmonary vein isolation (CIRCA-DOSE): methods and rationale.

PubMed

Andrade, Jason G; Deyell, Marc W; Badra, Mariano; Champagne, Jean; Dubuc, Marc; Leong-Sit, Peter; Macle, Laurent; Novak, Paul; Roux, Jean-Francois; Sapp, John; Tang, Anthony; Verma, Atul; Wells, George A; Khairy, Paul

2017-10-05

Pulmonary vein isolation (PVI) is an effective therapy for paroxysmal atrial fibrillation (AF), but it has limitations. The two most significant recent advances have centred on the integration of real-time quantitative assessment of catheter contact force into focal radio frequency (RF) ablation catheters and the development of dedicated ablation tools capable of achieving PVI with a single ablation lesion (Arctic Front cryoballoon, Medtronic, Minneapolis, MN, USA). Although each of these holds promise for improving the clinical success of catheter ablation of AF, there has not been a rigorous comparison of these advanced ablation technologies. Moreover, the optimal duration of cryoablation (freezing time) has not been determined. Patients undergoing an initial PVI procedure for paroxysmal AF will be recruited. Patients will be randomised 1:1:1 between contact-force irrigated RF ablation, short duration cryoballoon ablation (2 min applications) and standard duration cryoballoon ablation (4 min applications). The primary outcome is time to first documented AF recurrence on implantable loop recorder. With a sample size of 111 per group and a two-sided 0.025 significance level (to account for the two main comparisons), the study will have 80% power (using a log-rank test) to detect a difference of 20% between contact force RF catheter ablation and either of the two cryoballoon ablation groups. Factoring in a 4% loss to follow-up, 116 patients per group should be randomised and followed for a year (total study population of 348). The study was approved by the University of British Columbia Office of Research (Services) Ethics Clinical Research Ethics Board. Results of the study will be submitted for publication in a peer-reviewed journal. NCT01913522; Pre-results. © Article author(s) (or their employer(s) unless otherwise stated in the text of the article) 2017. All rights reserved. No commercial use is permitted unless otherwise expressly granted.

Twenty-four month results from a randomized trial of cyanoacrylate closure versus radiofrequency ablation for the treatment of incompetent great saphenous veins.

PubMed

Gibson, Kathleen; Morrison, Nick; Kolluri, Raghu; Vasquez, Michael; Weiss, Robert; Cher, Daniel; Madsen, Monte; Jones, Andrew

2018-06-15

We previously reported 3-month and 12-month occlusion rates after treatment of clinically symptomatic saphenous vein reflux with either cyanoacrylate closure (CAC) using the VenaSeal Closure System (Medtronic, Dublin, Ireland) or radiofrequency ablation (RFA) in a randomized, multicenter, clinical trial, VenaSeal Sapheon Closure System vs Radiofrequency Ablation for Incompetent Great Saphenous Veins (VeClose). Herein we report the 24-month follow-up results of the VeClose trial. There were 222 patients with symptomatic great saphenous vein (GSV) incompetence who were randomly assigned to receive either CAC (n = 108) or RFA (n = 114). Patients were not allowed to receive adjunctive treatment of tributary varicosities until after the 3-month visit. Duplex ultrasound of the target vein was performed at day 3 and months 1, 3, 6, 12, and 24 after treatment, and closure was assessed by ultrasound by the treating physician. Overall 24-month success rates were compared; in addition, time to first reopening of the target vein was evaluated using survival analysis. End points such as Venous Clinical Severity Score, EuroQoL-5 Dimension, and Aberdeen Varicose Vein Questionnaire were evaluated. Of 222 randomized patients, 171 completed the 24-month follow-up, which included 87 from the CAC group and 84 from the RFA group. The 24-month complete closure rate was 95.3% in the CAC group and 94.0% in the RFA group, demonstrating continued noninferiority of CAC compared with RFA (P = .0034). Symptoms and quality of life improved similarly in both groups. No clinically significant device- or procedure-related late adverse events occurred. Both CAC and RFA were effective in closure of the target GSV, resulting in similar and significant improvements in the patient's quality of life through 24 months. These results suggest that CAC of the GSV is safe and durable out to 2 years. Copyright © 2018 The Authors. Published by Elsevier Inc. All rights reserved.

Stand alone totally endoscopic epimyocardial ablation in patients with persistent atrial fibrillation and significant atrial dilatation.

PubMed

Wagner, Florian Mathias; Pecha, Simon; Conradi, Lenard; Reichenspurner, Hermann

2015-05-01

To analyze safety and efficacy of surgical totally endoscopic epimyocardial ablation in patients (pts) turned down for interventional catheter therapy due to long-standing persistent atrial fibrillation (pAF) combined with significant atrial dilatation (> 5 cm). Since December 2010, 15 pts were referred for surgical ablation due to persistent AF combined with biatrial dilatation (left atrium [LA] 5.0 ± 0.6 cm). Mean age was 52 ± 6 years, body mass index (BMI) 38 ± 6, duration of AF 2.8 ± 1.2 years, left ventricular end diastolic diameter (LVEDD) 5.8 cm ± 0.6 cm. Ablation was performed via a bilateral endoscopic approach using bipolar RF energy application. Monitoring was achieved by an event recorder (Reveal XT Medtronic, Inc., Minneapolis, MN, USA) or repeated 24-hours Holter electrocardiogram. All pts successfully received bilateral pulmonary vein isolation + box lesion + trigonal lesion + left atrial appendage resection. Mean duration of procedure was 235 ± 70 minutes. There was no intraoperative complication; however, one patient had persistent left phrenic nerve palsy. Mean hospital stay was 4 ± 2 days, mean follow-up time was 21 ± 11 months. Incidence of sinus rhythm (SR) was 67, 73, and 80% at discharge, three months, and 12 months follow-up. Mean LA diameter was reduced from 58.1 mm ± 6.0 mm preoperative to 49.7 mm ± 5.4 mm (p = 0.004) at 12 months follow-up. Incidence of SR was 86% at latest follow-up (mean time 21 months). All pts currently in SR (13/15 = 86%) are of class I or III antiarrhythmic drugs. Totally endoscopic left atrial ablation including left atrial resection can safely be performed. It achieved excellent rates of SR restoration in patients with long-standing persistent AF combined with significant atrial dilatation. © 2015 Wiley Periodicals, Inc.

"Power-on resets" in cardiac implantable electronic devices during magnetic resonance imaging.

PubMed

Higgins, John V; Sheldon, Seth H; Watson, Robert E; Dalzell, Connie; Acker, Nancy; Cha, Yong-Mei; Asirvatham, Samuel J; Kapa, Suraj; Felmlee, Joel P; Friedman, Paul A

2015-03-01

Magnetic resonance imaging (MRI) has been safely performed in some patients with cardiac implantable electronic devices (CIEDs) under careful monitoring and prespecified conditions. Pacemaker-dependent patients are often excluded, partly because of the potential for "power-on reset" (PoR), which can lead to a change from asynchronous to inhibited pacing with consequent inhibition of pacing due to electromagnetic interference during MRI. The purpose of this study was to review risk factors for PoR during MRI. A prospective study was performed between January 2008 and May 2013 in patients with CIEDs undergoing clinically indicated MRI. Eligible patients were not pacemaker dependent. Devices were interrogated before and after MRI, programmed to an asynchronous mode or an inhibition mode with tachyarrhythmia therapies turned off, and reprogrammed to their original settings after MRI. MRI scans (n = 256) were performed in 198 patients with non-MRI-conditional CIEDs between 2008 and 2013 (median age 66 years; interquartile range 57-77 years; 59% men). PoR occurred during 9 MRI scans (3.5%) in 8 patients. PoR was more frequent with Medtronic devices than with other generator brands (n = 9/139 vs 0/117 [6% vs 0%]; P = .005). Devices with PoR were all released before 2002 and were implanted from 1999 to 2004. Effects of PoR included a decrease in heart rate during MRI (n = 4) and transient anomalous battery life indication (n = 1). All devices functioned normally after MRI. PoR occurs infrequently but can cause deleterious changes in pacing mode and heart rate. MRI should not be performed in pacemaker-dependent patients with older at-risk generators. Continuous monitoring during MRI is essential because unrecognized PoR may inhibit pacing or accelerate battery depletion due to high pacing output. Copyright © 2015 Heart Rhythm Society. Published by Elsevier Inc. All rights reserved.

Risk of Sprint Fidelis defibrillator lead failure is highly dependent on age.

PubMed

Girerd, Nicolas; Nonin, Emilie; Pinot, Julien; Morel, Elodie; Flys, Carine; Scridon, Alina; Chevalier, Philippe

2011-01-01

In 2007, Medtronic Sprint Fidelis defibrillator leads were taken off the market due to a high rate of lead failure. Current data do not allow for risk stratification of patients with regard to lead failure. We sought to determine predictors of Sprint Fidelis lead failure. Between 2004 and 2007, 269 Sprint Fidelis leads were implanted in 258 patients in our centre. Variables associated with lead failure were assessed by the Kaplan-Meier method and a Cox survival model. During a median follow-up of 2.80 years (maximum 5.32), we observed 33 (12.3%) Sprint Fidelis lead failures (5-year survival, 65.6% ± 7.5%). In univariate analysis, age was the only predictor of lead failure (hazard ratio [HR] for 1-year increase 0.97; 95% confidence interval [CI] 0.95-0.99; p=0.009). Patients aged<62.5 years (median) had a significantly increased risk of lead failure compared with patients aged>62.5 years (HR 2.80; CI 1.30-6.02; p=0.009). Survival without Sprint Fidelis lead failure was 55.6% ± 10.4%) in patients aged<62.5 years (24/134 leads) vs 78.6% ± 8.8% in patients aged>62.5 years (9/135 leads). The annual incidence of lead failure in patients aged<62.5 years was 11.6% ± 4.9% during the fourth year after implantation and 22.9% ± 13.2% during the fifth year. Overall, we found a higher rate of Sprint Fidelis lead dysfunction than previously described. Lead failure was much more frequent in younger patients. Our results emphasize the need for close follow-up of younger patients with Sprint Fidelis leads and suggest that, in these patients, the implantation of a new implantable cardioverter defibrillator lead at the time of generator replacement might be reasonable. Copyright © 2011 Elsevier Masson SAS. All rights reserved.

TriGuard™ HDH embolic deflection device for cerebral protection during transcatheter aortic valve replacement.

PubMed

Samim, Mariam; van der Worp, Bart; Agostoni, Pierfrancesco; Hendrikse, Jeroen; Budde, Ricardo P J; Nijhoff, Freek; Ramjankhan, Faiz; Doevendans, Pieter A; Stella, Pieter R

2017-02-15

This study aims to evaluate the safety and performance of the new embolic deflection device TriGuard™HDH in patients undergoing TAVR. Transcatheter aortic valve replacement (TAVR) is associated with a high incidence of new cerebral ischemic lesions. The use of an embolic protection device may reduce the frequency of TAVR-related embolic events. This prospective, single arm feasibility pilot study included 14 patients with severe symptomatic aortic stenosis scheduled for TAVR. Cerebral diffusion weighted magnetic resonance imaging (DWI) was planned in all patients one day before and at day 4 (±2) after the procedure. Major adverse cerebral and cardiac events (MACCEs) were recorded for all patients. Primary endpoints of this study were I) device performance success defined as coverage of the aortic arch takeoffs throughout the entire TAVR procedure and II) MACCE occurrence. Secondary endpoints included the number and the volume of new cerebral ischemic lesions on DWI. Thirteen patients underwent transfemoral TAVR and one patient a transapical procedure. Edwards SAPIEN valve prosthesis was implanted in 8 (57%) patients and Medtronic CoreValve prosthesis in the remaining 6 (43%). Predefined performance success of the TriGuard™HDH device was achieved in 9 (64%) patients. The composite endpoint MACCE occurred in none of the patients. Post-procedural DWI was performed in 11 patients. Comparing the DWI of these patients to a historical control group showed no reduction in number [median 5.5 vs. 5.0, P = 0.857], however there was a significant reduction in mean lesion volume per patient [median 13.8 vs. 25.1, P = 0.049]. This study showed the feasibility and safety of using the TriGuard™HDH for cerebral protection during TAVR. This device did not decrease the number of post-procedural new cerebral DWI lesions, however its use showed decreased lesion volume as compared to unprotected TAVR. © 2016 Wiley Periodicals, Inc. © 2016 Wiley Periodicals, Inc.

Economic impact of longer battery life of cardiac resynchronization therapy defibrillators in Sweden.

PubMed

Gadler, Fredrik; Ding, Yao; Verin, Nathalie; Bergius, Martin; Miller, Jeffrey D; Lenhart, Gregory M; Russell, Mason W

2016-01-01

The objective of this study was to quantify the impact that longer battery life of cardiac resynchronization therapy defibrillator (CRT-D) devices has on reducing the number of device replacements and associated costs of these replacements from a Swedish health care system perspective. An economic model based on real-world published data was developed to estimate cost savings and avoided device replacements for CRT-Ds with longer battery life compared with devices with industry-standard battery life expectancy. Base-case comparisons were performed among CRT-Ds of three manufacturers - Boston Scientific Corporation, St. Jude Medical, and Medtronic - over a 6-year time horizon, as per the available clinical data. As a sensitivity analysis, we evaluated CRT-Ds as well as single-chamber implantable cardioverter defibrillator (ICD-VR) and dual-chamber implantable cardioverter defibrillator (ICD-DR) devices over a longer 10-year period. All costs were in 2015 Swedish Krona (SEK) discounted at 3% per annum. Base-case analysis results show that up to 603 replacements and up to SEK 60.4 million cumulative-associated costs could be avoided over 6 years by using devices with extended battery life. The pattern of savings over time suggests that savings are modest initially but increase rapidly beginning in the third year of follow-up with each year's cumulative savings two to three times the previous year. Evaluating CRT-D, ICD-VR, and ICD-DR devices together over a longer 10-year period, the sensitivity analysis showed 2,820 fewer replacement procedures and associated cost savings of SEK 249.3 million for all defibrillators with extended battery life. Extended battery life is likely to reduce device replacements and associated complications and costs, which may result in important cost savings and a more efficient use of health care resources as well as a better quality of life for heart failure patients in Sweden.

Comparison of two independent systematic reviews of trials of recombinant human bone morphogenetic protein-2 (rhBMP-2): the Yale Open Data Access Medtronic Project.

PubMed

Low, Jeffrey; Ross, Joseph S; Ritchie, Jessica D; Gross, Cary P; Lehman, Richard; Lin, Haiqun; Fu, Rongwei; Stewart, Lesley A; Krumholz, Harlan M

2017-02-15

It is uncertain whether the replication of systematic reviews, particularly those with the same objectives and resources, would employ similar methods and/or arrive at identical findings. We compared the results and conclusions of two concurrent systematic reviews undertaken by two independent research teams provided with the same objectives, resources, and individual participant-level data. Two centers in the USA and UK were each provided with participant-level data on 17 multi-site clinical trials of recombinant human bone morphogenetic protein-2 (rhBMP-2). The teams were blinded to each other's methods and findings until after publication. We conducted a retrospective structured comparison of the results of the two systematic reviews. The main outcome measures included (1) trial inclusion criteria; (2) statistical methods; (3) summary efficacy and risk estimates; and (4) conclusions. The two research teams' meta-analyses inclusion criteria were broadly similar but differed slightly in trial inclusion and research methodology. They obtained similar results in summary estimates of most clinical outcomes and adverse events. Center A incorporated all trials into summary estimates of efficacy and harms, while Center B concentrated on analyses stratified by surgical approach. Center A found a statistically significant, but small, benefit whereas Center B reported no advantage. In the analysis of harms, neither showed an increased cancer risk at 48 months, although Center B reported a significant increase at 24 months. Conclusions reflected these differences in summary estimates of benefit balanced with small but potentially important risk of harm. Two independent groups given the same research objectives, data, resources, funding, and time produced broad general agreement but differed in several areas. These differences, the importance of which is debatable, indicate the value of the availability of data to allow for more than a single approach and a single interpretation of the data. PROSPERO CRD42012002040 and CRD42012001907 .

Partial renal coverage in endovascular aneurysm repair causes unfavorable renal flow patterns in an infrarenal aneurysm model.

PubMed

van de Velde, Lennart; Donselaar, Esmé J; Groot Jebbink, Erik; Boersen, Johannes T; Lajoinie, Guillaume P R; de Vries, Jean-Paul P M; Zeebregts, Clark J; Versluis, Michel; Reijnen, Michel M P J

2018-05-01

To achieve an optimal sealing zone during endovascular aneurysm repair, the intended positioning of the proximal end of the endograft fabric should be as close as possible to the most caudal edge of the renal arteries. Some endografts exhibit a small offset between the radiopaque markers and the proximal fabric edge. Unintended partial renal artery coverage may thus occur. This study investigated the consequences of partial coverage on renal flow patterns and wall shear stress (WSS). In vitro models of an abdominal aortic aneurysm were used to visualize pulsatile flow using two-dimensional particle image velocimetry under physiologic resting conditions. One model served as control and two models were stented with an Endurant endograft (Medtronic Inc, Minneapolis, Minn), one without and one with partial renal artery coverage with 1.3 mm of stent fabric extending beyond the marker (16% area coverage). The magnitude and oscillation of WSS, relative residence time, and backflow in the renal artery were analyzed. In both stented models, a region along the caudal renal artery wall presented with low and oscillating WSS, not present in the control model. A region with very low WSS (<0.1 Pa) was present in the model with partial coverage over a length of 7 mm compared with a length of 2 mm in the model without renal coverage. Average renal backflow area percentage in the renal artery incrementally increased from control (0.9%) to the stented model without (6.4%) and with renal coverage (18.8%). In this flow model, partial renal coverage after endovascular aneurysm repair causes low and marked oscillations in WSS, potentially promoting atherosclerosis and subsequent renal artery stenosis. Awareness of the device-dependent offset between the fabric edge and the radiopaque markers is therefore important in endovascular practice. Copyright © 2017 Society for Vascular Surgery. Published by Elsevier Inc. All rights reserved.

Direct Evidence of Acetaminophen Interference with Subcutaneous Glucose Sensing in Humans: A Pilot Study

PubMed Central

Basu, Ananda; Veettil, Sona; Dyer, Roy; Peyser, Thomas

2016-01-01

Abstract Background: Recent advances in accuracy and reliability of continuous glucose monitoring (CGM) devices have focused renewed interest on the use of such technology for therapeutic dosing of insulin without the need for independent confirmatory blood glucose meter measurements. An important issue that remains is the susceptibility of CGM devices to erroneous readings in the presence of common pharmacologic interferences. We report on a new method of assessing CGM sensor error to pharmacologic interferences using the example of oral administration of acetaminophen. Materials and Methods: We examined the responses of several different Food and Drug Administration–approved and commercially available CGM systems (Dexcom [San Diego, CA] Seven® Plus™, Medtronic Diabetes [Northridge, CA] Guardian®, and Dexcom G4® Platinum) to oral acetaminophen in 10 healthy volunteers without diabetes. Microdialysis catheters were placed in the abdominal subcutaneous tissue. Blood and microdialysate samples were collected periodically and analyzed for glucose and acetaminophen concentrations before and after oral ingestion of 1 g of acetaminophen. We compared the response of CGM sensors with the measured acetaminophen concentrations in the blood and interstitial fluid. Results: Although plasma glucose concentrations remained constant at approximately 90 mg/dL (approximately 5 mM) throughout the study, CGM glucose measurements varied between approximately 85 to 400 mg/dL (from approximately 5 to 22 mM) due to interference from the acetaminophen. The temporal profile of CGM interference followed acetaminophen concentrations measured in interstitial fluid (ISF). Conclusions: This is the first direct measurement of ISF concentrations of putative CGM interferences with simultaneous measurements of CGM performance in the presence of the interferences. The observed interference with glucose measurements in the tested CGM devices coincided temporally with appearance of acetaminophen in the ISF. The method applied here can be used to determine the susceptibility of current and future CGM systems to interference from acetaminophen or other exogenous pharmacologic agents. PMID:26784129

Challenges of coronary angiography and intervention in patients previously treated by TAVI.

PubMed

Blumenstein, Johannes; Kim, Won-Keun; Liebetrau, Christoph; Gaede, Luise; Kempfert, Joerg; Walther, Thomas; Hamm, Christian; Möllmann, Helge

2015-08-01

Since the beginning of the transcatheter aortic valve implantation (TAVI) era, many prosthetic valves have entered clinical practice. TAVI prostheses differ regarding stent design and some may potentially interfere with diagnostic or interventional catheters. The aim of our analysis was to evaluate the feasibility of coronary angiography (CA) or percutaneous coronary intervention (PCI) in patients with prior TAVI. From 2011 to 2014, 1,000 patients were treated by TAVI at our center using eight different valve prostheses (Symetis ACURATE TA and ACURATE TF; Medtronic CoreValve and Engager; JenaValve, SJM Portico; Edwards Lifesciences SAPIEN and SAPIEN XT). In this analysis, all patients were included who underwent either CA or PCI after TAVI. CA or PCI were rated as fully feasible when coronary ostia could be fully intubated, partially feasible when coronary arteries could be displayed only unselectively or unfeasible when coronary arteries could not be displayed. A total of 35 patients underwent CA/PCI after TAVI at our hospital. In all patients with valves implanted in a subcoronary position (SAPIEN n = 19; JenaValve n = 1), selective intubation was feasible using standard catheters. Out of 15 patients with valve types that are placed over the coronary ostia (CoreValve n = 10, ACURATE n = 4, Portico n = 1), selective intubation of coronary arteries was not possible in 9 cases, even with the use of different diagnostic catheters. Full accessibility was possible only in 3 cases. In 2 cases, display of the right CA was only feasible using unselective aortography. In 1 case, coronary arteries could not be displayed at all immediately after a valve-in-valve procedure. CA or PCI after TAVI is usually feasible. Devices that are placed in a partially supracoronary position, however, can interfere with diagnostic or guiding catheters and impede straightforward intervention, especially when the prosthesis is not implanted in the correct position.

Clinical and economic impact of remote monitoring on the follow-up of patients with implantable electronic cardiovascular devices: an observational study.

PubMed

Costa, Paulo Dias; Reis, A Hipólito; Rodrigues, Pedro P

2013-02-01

Traditional follow-up of patients with cardiovascular devices is still an activity that, in addition to serving an increasing population, requires a considerable amount of time and specialized human and technical resources. Our aim was to evaluate the applicability of the CareLink(®) (Medtronic, Minneapolis, MN) remote monitoring system as a complementary option to the follow-up of patients with implanted devices, between in-office visits. Evaluated outcomes included both clinical (event detection and time to diagnosis) and nonclinical (patient's satisfaction and economic costs) aspects. An observational, longitudinal, prospective study was conducted with patients from a Portuguese central hospital sampled by convenience during 1 week (43 patients). Data were collected in four moments: two in-office visits and two remote evaluations, reproducing 1 year of clinical follow-up. Data sources included health records, implant reports, initial demographic data collection, follow-up printouts, and a questionnaire. After selection criteria were verified, 15 patients (11 men [73%]) were included, 63.4±10.8 years old, representing 14.0±6.3 implant months. Clinically, 15 events were detected (9 by remote monitoring and 6 by patient-initiated activation), of which only 9 were symptomatic. We verified that remote monitoring could detect both symptomatic and asymptomatic events, whereas patient-initiated activation only detected symptomatic ones (p=0.028). Moreover, the mean diagnosis anticipation in patients with events was approximately 58 days (p<0.001). In nonclinical terms, we observed high or very high satisfaction (67% and 33%, respectively) with using remote monitoring technology, but still 8 patients (53%) stated they preferred in-office visits. Finally, the introduction of remote monitoring technology has the ability to reduce total follow-up costs for patients by 25%. We conclude that the use of this system constitutes a viable complementary option to the follow-up of patients with implantable devices, between in-office visits.

Patient satisfaction and suggestions for improvement of remote ICD monitoring.

PubMed

Petersen, Helen Høgh; Larsen, Mie Christa Jensen; Nielsen, Olav Wendelboe; Kensing, Finn; Svendsen, Jesper Hastrup

2012-09-01

The study aim was to evaluate patient acceptance and content with remote follow-up (FU) of their implantable cardioverter defibrillator (ICD) and to estimate patients' wish for changes in remote follow-up routines. Four hundred seventy-four ICD patients at the device follow-up clinic at Rigshospitalet using CareLink® (Medtronic) remote follow-up, who had made ≥2 transmissions, received a questionnaire. Three hundred eighty-five patients (81.2%) answered. Mean time with ICD was 56 ± 45 months and mean age was 62 ± 13 years; 80% was male. Diagnosis related to ICD implant was: ischemic heart disease in 56% and dilated cardiomyopathy in 21%. Twenty-six percent had primary prophylactic indication. Mean time on remote FU was 16.4 ± 6.9 months. Mean time spent on in-clinic FU (two-way transport and FU) was 4 h and 36 min ± 7 h and 50 min, excluding 12 patients from Greenland and Faroe Islands. Ninety-five percent of the patients was very content or content with remote FU compared to in-clinic FU; 3% was less content and 2% was not content. For scheduled transmissions, 21% of the patients wished for a faster reply (sms or e-mail) compared to current practice with a letter. Eighty-four percent preferred more detailed information concerning ICD leads, battery status, and ICD therapies. A total of 96 patients (25%) had performed extra unscheduled remote transmissions: 20 due to shock, 20 due to alarm, 35 due to palpitations, and 18 for other or combined reasons. Ninety-five percent of the patients were content with the remote FU. Only 25% had unscheduled transmissions and most unscheduled transmissions were for appropriate reasons. Eighty-four percent of the patients wished for a more detailed response and 21% wished for a faster reply after routine transmissions.

Culprit lesion thrombus burden after manual thrombectomy or percutaneous coronary intervention-alone in ST-segment elevation myocardial infarction: the optical coherence tomography sub-study of the TOTAL (ThrOmbecTomy versus PCI ALone) trial.

PubMed

Bhindi, Ravinay; Kajander, Olli A; Jolly, Sanjit S; Kassam, Saleem; Lavi, Shahar; Niemelä, Kari; Fung, Anthony; Cheema, Asim N; Meeks, Brandi; Alexopoulos, Dimitrios; Kočka, Viktor; Cantor, Warren J; Kaivosoja, Timo P; Shestakovska, Olga; Gao, Peggy; Stankovic, Goran; Džavík, Vladimír; Sheth, Tej

2015-08-01

Manual thrombectomy has been proposed as a strategy to reduce thrombus burden during primary percutaneous coronary intervention (PCI) in patients with ST-segment elevation myocardial infarction (STEMI). However, the effectiveness of manual thrombectomy in reducing thrombus burden is uncertain. In this substudy of the TOTAL (ThrOmbecTomy versus PCI ALone) trial, we compared the thrombus burden at the culprit lesion using optical coherence tomography (OCT) in patients treated with thrombectomy vs. PCI-alone. The TOTAL trial (N = 10 732) was an international, multicentre, randomized trial of thrombectomy (using the Export catheter, Medtronic Cardiovascular, Santa Rosa, CA, USA) in STEMI patients treated with primary PCI. The OCT substudy prospectively enrolled 214 patients from 13 sites in 5 countries. Optical coherence tomography was performed immediately after thrombectomy or PCI-alone and then repeated after stent deployment. Thrombus quantification was performed by an independent core laboratory blinded to treatment assignment. The primary outcome of pre-stent thrombus burden as a percentage of segment analysed was 2.36% (95% CI: 1.73-3.22) in the thrombectomy group and 2.88% (95% CI: 2.12-3.90) in the PCI-alone group (P = 0.373). Absolute pre-stent thrombus volume was not different (2.99 vs. 3.74 mm(3), P = 0.329). Other secondary outcomes of pre-stent quadrants of thrombus, post-stent atherothrombotic burden, and post-stent atherothrombotic volume were not different between groups. Manual thrombectomy did not reduce pre-stent thrombus burden at the culprit lesion compared with PCI-alone. Both strategies were associated with low thrombus burden at the lesion site after the initial intervention to restore flow. Published on behalf of the European Society of Cardiology. All rights reserved. © The Author 2015. For permissions please email: journals.permissions@oup.com.

Pure laparoscopic right hepatectomy for giant hemangioma using anterior approach.

PubMed

Kim, Seok-Hwan; Kim, Ki-Hun; Kirchner, Varvara A; Lee, Sang-Kyung

2017-05-01

Laparoscopic major hepatectomy remains a challenging procedure [1, 2]. In the case of giant tumors in the right liver, conventional approach (complete mobilization of the right liver before parenchymal transection) could be dangerous during mobilization because of large volume and weight [3, 4]. We present the case of a pure laparoscopic right hepatectomy for a giant hemangioma using an anterior approach. We achieved the informed consent with this patient and approved by the Ethics Committee of the Asan Medical Center. Giant hemangioma (13 × 11 × 14 cm) was located in right liver. After glissonean approach [5], Pringle maneuver was performed during the hepatic parenchymal transection. For the transection, the Cavitron Ultrasonic Surgical Aspirator was used. Small hepatic vein branches along the middle hepatic vein and small glissonean pedicles were sealed and divided with a THUNDERBEATTM (Olympus), which is the device with integration of both bipolar and ultrasonic energies delivered simultaneously. iDriveTM Ultra Powered Stapling device (Medtronic) was used for division of right glissonean pedicle and large hepatic veins. Hemangioma was removed through the lower abdominal transverse incision using the endo-bag. This technique has the advantage of avoiding excessive bleeding caused by avulsion of the hepatic vein and caval branches, iatrogenic tumor rupture [3]. By means of the anterior approach, pure laparoscopic right hepatectomy was performed successfully without intraoperative complications and transfusions. The operation time was 202 min, and the estimated blood loss was less than 150 ml. On postoperative day 3, computed tomographic scan showed no pathological findings. The patient was discharged on postoperative day 5 without complications. Laparoscopic approach has good results because of the view with magnification enabling meticulous hemostasis and the small wounds that give patients less pain [6, 7]. The authors recommend that the laparoscopic anterior approach is safe and feasible for right hepatectomy, even for giant tumors.

Contribution of intraoperative neuromonitoring to the identification of the external branch of superior laryngeal nerve

PubMed Central

Aygün, Nurcihan; Uludağ, Mehmet; İşgör, Adnan

2017-01-01

Objective We evaluated the contribution of intraoperative neuromonitoring to the visual and functional identification of the external branch of the superior laryngeal nerve. Material and Methods The prospectively collected data of patients who underwent thyroid surgery with intraoperative neuromonitoring for external branch of the superior laryngeal nerve exploration were assessed retrospectively. The surface endotracheal tube-based Medtronic NIM3 intraoperative neuromonitoring device was used. The external branch of the superior laryngeal nerve function was evaluated by the cricothyroid muscle twitch. In addition, contribution of external branch of the superior laryngeal nerve to the vocal cord adduction was evaluated using electromyographic records. Results The study included data of 126 (female, 103; male, 23) patients undergoing thyroid surgery, with a mean age of 46.2±12.2 years (range, 18–75 years), and 215 neck sides were assessed. Two hundred and one (93.5%) of 215 external branch of the superior laryngeal nerves were identified, of which 60 (27.9%) were identified visually before being stimulated with a monopolar stimulator probe. Eighty-nine (41.4%) external branch of the superior laryngeal nerves were identified visually after being identified with a probe. Although 52 (24.1%) external branch of the superior laryngeal nerves were identified with a probe, they were not visualized. Intraoperative neuromonitoring provided a significant contribution to visual (p<0.001) and functional (p<0.001) identification of external branch of the superior laryngeal nerves. Additionally, positive electromyographic responses were recorded from 160 external branch of the superior laryngeal nerves (74.4%). Conclusion Intraoperative neuromonitoring provides an important contribution to visual and functional identification of external branch of the superior laryngeal nerves. We believe that it can not be predicted whether the external branch of the superior laryngeal nerve is at risk or not and the nerve is often invisible; thus, intraoperative neuromonitoring may routinely be used in superior pole dissection. Glottic electromyography response obtained via external branch of the superior laryngeal nerve stimulation provides quantifiable information in addition to the simple visualization of the cricothyroid muscle twitch. PMID:28944328

Usability of therapy controllers in elderly patients with deep brain stimulation

PubMed Central

2012-01-01

Background Technical devices are becoming more prevalent in society and also in medical care. Older adults need more support to learn new technologies than younger subjects. So far, no research has been done on the usability of patient controllers in deep brain stimulation in an elderly population. The aim of the study was to investigate the factors influencing the performance of elderly DBS patients with respect to usability aspects of Medtronic Access therapy controllers. Methods Time, mistakes and frequency of use of the controller were compared in 41 elderly DBS patients who prior to the study had already owned a therapy controller for more than six years. One group (n = 20, mean age = 66.4 years) was watching an instructional video and then completed practical assignments on a model implantable pulse generator (IPG). The other group (n = 21, mean age = 65.9 years) completed the tasks without having seen the video before. Any errors that patients made were documented and also corrected so that all of them received hands-on training. After six months all patients were re-evaluated on the dummy IPG in order to compare the effects of hands-on alone vs. video-based training combined with hands-on. Results The group that had seen the video before significantly outperformed the control group at both assessments with respect to number of errors. Both groups performed faster after six months compared to baseline and tend to use the controller more often than at baseline. Conclusion Our results indicate that elderly DBS patients who have been using the controller for several years still have various difficulties in operating the device. However, we also showed that age-specific training may improve the performance in older adults. In general, the design of DBS patient controllers should focus on the specific needs of the end-users. But as changes to medical devices take a long time to be implemented, video instructions with age-specific content plus hands-on training may improve learning for older adults. PMID:22330892

Mechanical valve replacement in congenital heart disease.

PubMed

Fiane, A E; Lindberg, H L; Saatvedt, K; Svennevig, J L

1996-05-01

Mechanical valves are the prosthesis of choice in valve replacement in children. However, the problem of somatic growth leading to patient-valve mismatch remains present, and the appropriate anticoagulation regimen remains controversial. We present our experience of valve replacement in a young population over 20 years. Between 1972 and 1992, 48 patients (34 males and 14 females), mean age 11.2 years (range 0.4-27.4 years), underwent mechanical valve replacement at our institution. Aortic valve replacement was performed in 28 patients (58.3%), mitral valve replacement in 13 (27.1%), tricuspid valve replacement in six (12.5%) and pulmonary valve replacement in one patient (2.1%). The prostheses used were: St. Jude Medical (n = 2), Björk-Shiley (n = 14), Medtronic Hall (n = 16), Duromedics (n = 2) and CarboMedics (n = 14). Early mortality was 14.3%, 10.7% for aortic valve replacement and 30.8% for mitral valve replacement. Mean follow up for all patients was 8.3 years (range 0-22 years), with a total of 398 patient-years. Seven patients died during the follow up (17.1%). Survival after 10 years, including operative mortality, was 81% for aortic valve replacement, 33% for mitral valve replacement, 83% for tricuspid valve replacement and 100% for pulmonary valve replacement. All patients were anticoagulated with warfarin. In eight patients (16.7%) an antiplatelet drug (aspirin or dipyridamole) was added. Major events included paravalvular leak in six patients (1.5%/pty), valve thrombosis in five (mitral position in two, tricuspid in three) (1.3%/pty) and endocarditis in one patient (0.3%/pty). Minor thromboembolic events occurred in three patients (0.8%/pty) and minor hemorrhagic events in three (0.8%/pty). No patients developed hemolytic anemia and there was no case of structural failure. In our experience, mechanical prostheses in congenital heart disease were associated with significant morbidity and mortality, however long term survival after aortic valve replacement was good (81% at 10 years). Thromboembolic and hemorrhagic events were of minor significance. Atrio-ventricular valve replacement carried the highest risk of valve thrombosis and we now give warfarin and an antiplatelet drug to children undergoing mechanical valve implantation in this position.

The accuracy and efficacy of real-time continuous glucose monitoring sensor in Chinese diabetes patients: a multicenter study.

PubMed

Zhou, Jian; Lv, Xiaofeng; Mu, Yiming; Wang, Xianling; Li, Jing; Zhang, Xingguang; Wu, Jinxiao; Bao, Yuqian; Jia, Weiping

2012-08-01

The purpose of this multicenter study was to investigate the accuracy of a real-time continuous glucose monitoring sensor in Chinese diabetes patients. In total, 48 patients with type 1 or 2 diabetes from three centers in China were included in the study. The MiniMed Paradigm(®) 722 insulin pump (Medtronic, Northridge, CA) was used to monitor the real-time continuous changes of blood glucose levels for three successive days. Venous blood of the subjects was randomly collected every 15 min for seven consecutive hours on the day when the subjects were wearing the sensor. Reference values were provided by the YSI(®) 2300 STAT PLUS™ glucose and lactate analyzer (YSI Life Sciences, Yellow Springs, OH). In total, 1,317 paired YSI-sensor values were collected from the 48 patients. Of the sensor readings, 88.3% (95% confidence interval, 0.84-0.92) were within±20% of the YSI values, and 95.7% were within±30% of the YSI values. Clarke and consensus error grid analyses showed that the ratios of the YSI-sensor values in Zone A to the values in Zone B were 99.1% and 99.9%, respectively. Continuous error grid analysis showed that the ratios of the YSI-sensor values in the region of accurate reading, benign errors, and erroneous reading were 96.4%, 1.8%, and 1.8%, respectively. The mean absolute relative difference (ARD) for all subjects was 10.4%, and the median ARD was 7.8%. Bland-Altman analysis detected a mean blood glucose level of 3.84 mg/dL. Trend analysis revealed that 86.1% of the difference of the rates of change between the YSI values and the sensor readings occurred within the range of 1 mg/dL/min. The Paradigm insulin pump has high accuracy in both monitoring the real-time continuous changes and predicting the trend of changes in blood glucose level. However, actual clinical manifestations should be taken into account for diagnosis of hypoglycemia.

Safety and efficacy of the predictive low glucose management system in the prevention of hypoglycaemia: protocol for randomised controlled home trial to evaluate the Suspend before low function.

PubMed

Abraham, M B; Nicholas, J A; Ly, T T; Roby, H C; Paramalingam, N; Fairchild, J; King, B R; Ambler, G R; Cameron, F; Davis, E A; Jones, T W

2016-04-15

Innovations with sensor-augmented pump therapy (SAPT) to reduce hypoglycaemia in patients with type 1 diabetes are an ongoing area of research. The predictive low glucose management (PLGM) system incorporates continuous glucose sensor data into an algorithm and suspends basal insulin before the occurrence of hypoglycaemia. The system was evaluated in in-clinic studies, and has informed the parameters of a larger home trial to study its efficacy and safety in real life. The aim of this report is to describe the study design and outcome measures for the trial. This is a 6-month, multicentre, randomised controlled home trial to test the PLGM system in children and adolescents with type 1 diabetes. The system is available in the Medtronic MiniMed 640G pump as the 'Suspend before low' feature. Following a run-in period, participants are randomised to either the control arm with SAPT alone or the intervention arm with SAPT and Suspend before low. The primary aim of this study is to evaluate the time spent hypoglycaemic (sensor glucose <3.5 mmol/L) with and without the system. The secondary aims are to determine the number of hypoglycaemic events, the time spent hyperglycaemic, and to evaluate safety with ketosis and changes in glycated haemoglobin. The study also aims to assess the changes in counter-regulatory hormone responses to hypoglycaemia evaluated by a hyperinsulinaemic hypoglycaemic clamp in a subgroup of patients with impaired awareness. Validated questionnaires are used to measure the fear of hypoglycaemia and the impact on the quality of life to assess burden of the disease. Ethics committee permissions were gained from respective Institutional Review boards. The findings of the study will provide high quality evidence of the ability of the system in the prevention of hypoglycaemia in real life. ACTRN12614000510640, Pre-results. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/

Prevention of hypoglycemia by using low glucose suspend function in sensor-augmented pump therapy.

PubMed

Danne, Thomas; Kordonouri, Olga; Holder, Martin; Haberland, Holger; Golembowski, Sven; Remus, Kerstin; Bläsig, Sara; Wadien, Tanja; Zierow, Susanne; Hartmann, Reinhard; Thomas, Andreas

2011-11-01

Severe hypoglycemic episodes are a barrier for achieving optimal glycemic control. Sensor-augmented pump (SAP) therapy with insulin in combination with a novel mechanism of automatic insulin shutoff (low glucose suspend [LGS]) can be used to prevent and reduce hypoglycemia. In a prospective study, we investigated the effect of the LGS algorithm on the frequency of hypoglycemia in children and adolescents with type 1 diabetes under real-life conditions. Twenty-one patients with type 1 diabetes (10.8±3.8 years old, duration of diabetes 5.9±3.0 years, pump therapy for 3.7±1.7 years, glycated hemoglobin level 7.8±1.1%) from three pediatric centers used the Paradigm(®) Veo(™) system (Medtronic Minimed, Northridge, CA) during two subseqent time periods: SAP without LGS for 2 weeks and then SAP with LGS enabled for 6 weeks. The primary objective was to assess the frequency of hypoglycemic episodes when using the LGS feature with an insulin delivery shutoff of a maximum of 2 h at a sensor glucose level below 70 mg/dL (3.9 mmol/L). In total, 1,298 LGS alerts occurred (853 shorter than 5 min). Forty-two percent of LGS activations (>5 min) lasted less than 30 min, whereas 24% had a duration of 2 h. The number of hypoglycemic excursions (average/day) was reduced during SAP+LGS (<70 mg/L, 1.27±0.75 vs. 0.95±0.49, P=0.010; ≤40 mg/dL, 0.28±0.18 vs. 0.13±0.14, P=0.005) as was the time spent in hypoglycemia (average minutes/day, 101±68 vs. 58±33, P=0.002) without significant difference in the mean glucose level (145±23 vs. 148±19 mg/dL). No episodes of severe hyperglycemia or diabetic ketoacidosis were observed following LGS activation. The present investigation provides evidence that SAP with LGS reduces the frequency of hypoglycemia without compromising safety.

A clinical trial of the accuracy and treatment experience of the Dexcom G4 sensor (Dexcom G4 system) and Enlite sensor (guardian REAL-time system) tested simultaneously in ambulatory patients with type 1 diabetes.

PubMed

Matuleviciene, Viktorija; Joseph, Jeffrey I; Andelin, Mervi; Hirsch, Irl B; Attvall, Stig; Pivodic, Aldina; Dahlqvist, Sofia; Klonoff, David; Haraldsson, Börje; Lind, Marcus

2014-11-01

Continuous glucose monitoring (CGM) is a tool widely used in the treatment of patients with type 1 diabetes. The purpose of the current study was to evaluate whether accuracy and patient treatment satisfaction differ between the Enlite™ (Medtronic MiniMed, Inc., Northridge, CA) and Dexcom(®) (San Diego, CA) G4 PLATINUM CGM sensors. Thirty-eight ambulatory patients with type 1 diabetes used the Dexcom G4 and Enlite sensors simultaneously for a minimum of 4 and maximum of 6 days. Patients measured capillary glucose levels with a HemoCue(®) (Ängelholm, Sweden) system six to 10 times a day. In addition, two inpatient studies were performed between Days 1-3 and 4-6. The mean absolute relative difference (MARD) in blood glucose for the Dexcom G4 was significantly lower (13.9%) than for the Enlite sensor (17.8%) (P<0.0001). The corresponding MARDs for Days 1-3 were 15.0% versus 19.4% (P=0.0027) and 13.6% versus 15.9% (P=0.026) for Days 4-6. For glucose levels in the hypoglycemic range (<4.0 mmol/L), the MARD for the Dexcom G4 was 20.0% compared with 34.7% for the Enlite (P=0.0041). On a visual analog scale (VAS) (0-100), patients rated the Dexcom G4 more favorably than the Enlite in 12 out of the 13 user experience questions. For example, more patients rated their experience with the Dexcom G4 as positive (VAS, 79.7 vs. 46.6; P<0.0001) and preferred to use it in their daily lives (VAS, 79.1 vs. 42.1; P<0.0001). The Dexcom G4 sensor was associated with greater overall accuracy than the Enlite sensor during initial (Days 1-3) and later (Days 4-6) use and for glucose levels in the hypoglycemic range. Patients reported a significantly more positive experience using the Dexcom G4 than the Enlite.

Long-Term Health Benefit of Transcatheter Aortic Valve Replacement in Patients With Chronic Lung Disease.

PubMed

Crestanello, Juan A; Popma, Jeffrey J; Adams, David H; Deeb, G Michael; Mumtaz, Mubashir; George, Barry; Huang, Jian; Reardon, Michael J

2017-11-27

This study sought to characterize the long-term effect of chronic lung disease (CLD) on mortality, clinical outcomes, quality of life, and health benefits after transcatheter aortic valve replacement (TAVR) with a self-expanding bioprosthesis. The long-term effect of CLD after TAVR is unknown. Prevalence and severity of CLD was determined at baseline in high- and extreme-risk patients with aortic stenosis from the CoreValve US Pivotal Trial. Clinical outcomes and health status were assessed using the Kansas City Cardiomyopathy Questionnaire overall summary score (KCCQ-OS). A favorable health benefit was defined as alive with a KCCQ-OS ≥60 and stability (<10-point decrease) or improvement in the KCCQ-OS from baseline. CLD was present in 55% (20% mild, 13% moderate, 22% severe) of the 1,030 patients studied. All-cause mortality was higher in patients with moderate and severe CLD at 1 year (19.6% mild, 28.1% moderate, 26.9% severe CLD vs. 19.2% non-CLD; p = 0.030) and 3 years (44.8% mild, 53.0% moderate, 51.9% severe vs. 37.7% non-CLD; p < 0.001). New York Heart Association functional class improved in more than 80% of patients with CLD at 1 and 3 years. All patients had a nearly 20-point improvement in KCCQ-OS at 1 and 3 years. However, only 43.3% of patients with CLD had a favorable health benefit at 1 year and 22.5% at 3 years. Moderate and severe CLD increases 1- and 3-year mortality after TAVR. Although functional status and quality of life were improved in CLD at 1 and 3 years after TAVR, a favorable health benefit was only achieved in selected patients. (Safety and Efficacy Study of the Medtronic CoreValve System in the Treatment of Symptomatic Severe Aortic Stenosis in High Risk and Very High Risk Subjects Who Need Aortic Valve Replacement; NCT01240902). Copyright © 2017 American College of Cardiology Foundation. Published by Elsevier Inc. All rights reserved.

Porous, Dexamethasone-loaded polyurethane coatings extend performance window of implantable glucose sensors in vivo.

PubMed

Vallejo-Heligon, Suzana G; Brown, Nga L; Reichert, William M; Klitzman, Bruce

2016-01-01

Continuous glucose sensors offer the promise of tight glycemic control for insulin dependent diabetics; however, utilization of such systems has been hindered by issues of tissue compatibility. Here we report on the in vivo performance of implanted glucose sensors coated with Dexamethasone-loaded (Dex-loaded) porous coatings employed to mediate the tissue-sensor interface. Two animal studies were conducted to (1) characterize the tissue modifying effects of the porous Dex-loaded coatings deployed on sensor surrogate implants and (2) investigate the effects of the same coatings on the in vivo performance of Medtronic MiniMed SOF-SENSOR™ glucose sensors. The tissue response to implants was evaluated by quantifying macrophage infiltration, blood vessel formation, and collagen density around implants. Sensor function was assessed by measuring changes in sensor sensitivity and time lag, calculating the Mean Absolute Relative Difference (MARD) for each sensor treatment, and performing functional glucose challenge test at relevant time points. Implants treated with porous Dex-loaded coatings diminished inflammation and enhanced vascularization of the tissue surrounding the implants. Functional sensors with Dex-loaded porous coatings showed enhanced sensor sensitivity over a 21-day period when compared to controls. Enhanced sensor sensitivity was accompanied with an increase in sensor signal lag and MARD score. These results indicate that Dex-loaded porous coatings were able to elicit an attenuated tissue response, and that such tissue microenvironment could be conducive towards extending the performance window of glucose sensors in vivo. In the present article, a coating to extend the functionality of implantable glucose sensors in vivo was developed. Our study showed that the delivery of an anti-inflammatory agent with the presentation of micro-sized topographical cues from coatings may lead to improved long-term glucose sensor function in vivo. We believe that improved function of sensors treated with the novel coatings was a result of the observed decreases in inflammatory cell density and increases in vessel density of the tissue adjacent to the devices. Furthermore, extending the in vivo functionality of implantable glucose sensors may lead to greater adoption of these devices by diabetic patients. Copyright © 2015 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.

Topographical and functional anatomy of trapezius muscle innervation by spinal accessory nerve and C2 to C4 nerves of cervical plexus.

PubMed

Gavid, M; Mayaud, A; Timochenko, A; Asanau, A; Prades, J M

2016-10-01

The aim of this study was to determine the existence and the frequency of communicating branches between the spinal accessory nerve (SAN) and the C2, C3 and C4 roots of the cervical plexus. The present study also aimed to elucidate whether these branches contain motor fibers or not. Dissection of the cervical region was performed on twelve adult cadavers. A powered operating microscope was necessary to dissect the SAN and its branches and also to dissect C2, C3 and C4 nerve branches. In a second step, data from 13 patients who underwent 25 modified neck dissections under trapezius muscle's monitoring were collected. At the end of surgery, intraoperative stimulation on the SAN, C2, C3 and C4 nerve branches was performed. Registered potentials in the three parts of the trapezius muscle, using the NIM Medtronic system, were analyzed. During cadaver dissection, 18 (78 %) communicating branches were identified between the SAN and C2, 11 (48 %) between the SAN and C3, 12 (52 %) between the SAN and C4. Intraoperative stimulation of the SAN and its branch for the trapezius muscle provided a significant electroneurographic response in the three parts of the trapezius muscle in all subjects. Intraoperative stimulation of C3 led to recordable contractions of the trapezius muscle in 5 (20 %) modified neck surgeries, stimulation of C4 led to recordable contractions during 5 (20 %) modified neck dissections. One case of contraction was recorded after intraoperative stimulation of C2 (7 %). Although we were able to identify at least one communicating branch between the SAN and the roots of the cervical plexus in each cadaver dissection, the cervical plexus is not always involved in trapezius motor innervation. Intraoperative electroneurography demonstrated that a motor input from the cervical plexus to the trapezius muscle was provided in only 32 % of cases. Therefore, SAN trunk and C3-C4 roots should be carefully preserved during modified neck dissection to protect trapezius and shoulder functions.

A media player causes clinically significant telemetry interference with implantable loop recorders.

PubMed

Thaker, Jay P; Patel, Mehul B; Shah, Ashok J; Liepa, Valdis V; Jongnarangsin, Krit; Thakur, Ranjan K

2009-03-01

The implantable loop recorder is a useful diagnostic tool for intermittent cardiovascular symptoms because it can automatically record arrhythmias as well as a patient-triggered ECG. Media players have been shown to cause telemetry interference with pacemakers. Telemetry interference may be important in patients with implantable loop recorders because capturing a patient-triggered ECG requires a telemetry link between a hand-held activator and the implanted device. The purpose of this study was to determine if a media player causes interference with implantable loop recorders. Fourteen patients with implantable loop recorders underwent evaluation for interference with a 15 GB third generation iPod (Apple, Inc.) media player. All patients had the Reveal Plus (Medtronic, Inc.) implantable loop recorder. We tested for telemetry interference on the programmer by first establishing a telemetry link with the loop recorder and then, the media player was placed next to it, first turned off and then, on. We evaluated for telemetry interference between the activator and the implanted device by placing the activator over the device (normal use) and the media player next to it, first turned off and then, on. We made 5 attempts to capture a patient-triggered ECG by depressing the activator switch 5 times while the media player was off or on. Telemetry interference on the programmer screen, consisting of either high frequency spikes or blanking of the ECG channel was seen in all patients. Telemetry interference with the activator resulted in failure to capture an event in 7 patients. In one of these patients, a green indicator light on the activator suggested that a patient-triggered event was captured, but loop recorder interrogation did not show a captured event. In the remaining 7 patients, an event was captured and appropriately recognized by the device at least 1 out of 5 times. A media player playing in close proximity to an implanted loop recorder may interfere with capture of a patient-triggered event. Patients should be advised to keep media players away from their implanted loop recorder.

Glucose-lowering effect and glycaemic variability of insulin glargine, insulin detemir and insulin lispro protamine in people with type 1 diabetes.

PubMed

Derosa, G; Franzetti, I; Querci, F; Romano, D; D'Angelo, A; Maffioli, P

2015-06-01

To compare, using a continuous glucose monitoring (CGM) system, the effect on glycaemic variability of insulin glargine, detemir and lispro protamine. A total of 49 white people with type 1 diabetes, not well controlled by three times daily insulin lispro, taken for at least 2 months before study and on a stable dose, were enrolled. The study participants were randomized to add insulin glargine, detemir or lispro protamine, once daily, in the evening. We used a CGM system, the iPro Digital Recorder (Medtronic MiniMed, Northridge, CA, USA) for 1 week. Glycaemic control was assessed according to mean blood glucose values, the area under the glucose curve above 3.9 mmol/l (AUC(>3.9)) or above 10.0 mmol/l (AUC(>10.0)), and the percentage of time spent with glucose values >3.9 or >10.0 mmol/l. Intraday glycaemic variability was assessed using standard deviation (s.d.) values, the mean amplitude of glycaemic excursions and continuous overlapping of net glycaemic action. Day-to-day glycaemic variability was assessed using the mean of daily differences. The s.d. was found to be significantly lower with insulin lispro protamine and glargine compared with insulin detemir. AUC(>3.9) was higher and AUC(>10.0) was lower with insulin lispro protamine and glargine compared with detemir. The mean amplitude of glycaemic excursions and continuous overlapping net glycaemic action values were lower with insulin lispro protamine and glargine compared with detemir. In addition, the mean of daily differences was significantly lower with insulin lispro protamine and glargine compared with detemir. Fewer hypoglycaemic events were recorded during the night-time with insulin lispro protamine compared with glargine and detemir. The results suggest that insulin lispro protamine and glargine are more effective than detemir in reducing glycaemic variability and improving glycaemic control in people with type 1 diabetes. Insulin lispro protamine seems to lead to fewer hypoglycaemic events than other insulin regimens. © 2015 John Wiley & Sons Ltd.

Radiofrequency bipolar hemostatic sealer reduces blood loss, transfusion requirements, and cost for patients undergoing multilevel spinal fusion surgery: a case control study.

PubMed

Frank, Steven M; Wasey, Jack O; Dwyer, Ian M; Gokaslan, Ziya L; Ness, Paul M; Kebaish, Khaled M

2014-07-05

A relatively new method of electrocautery, the radiofrequency bipolar hemostatic sealer (RBHS), uses saline-cooled delivery of energy, which seals blood vessels rather than burning them. We assessed the benefits of RBHS as a blood conservation strategy in adult patients undergoing multilevel spinal fusion surgery. In a retrospective cohort study, we compared blood utilization in 36 patients undergoing multilevel spinal fusion surgery with RBHS (Aquamantys, Medtronic, Minneapolis, MN, USA) to that of a historical control group (n = 38) matched for variables related to blood loss. Transfusion-related costs were calculated by two methods. Patient characteristics in the two groups were similar. Intraoperatively, blood loss was 55% less in the RBHS group than in the control group (810 ± 530 vs. 1,800 ± 1,600 mL; p = 0.002), and over the entire hospital stay, red cell utilization was 51% less (2.4 ± 3.4 vs. 4.9 ± 4.5 units/patient; p = 0.01) and plasma use was 56% less (1.1 ± 2.4 vs. 2.5 ± 3.4 units/patient; p = 0.03) in the RBHS group. Platelet use was 0.1 ± 0.5 and 0.3 ± 0.6 units/patient in the RBHS and control groups, respectively (p = 0.07). The perioperative decrease in hemoglobin was less in the RBHS group than in the control group (-2.0 ± 2.2 vs. -3.2 ± 2.1 g/dL; p = 0.04), and hemoglobin at discharge was higher in the RBHS group (10.5 ± 1.4 vs. 9.7 ± 0.9 g/dL; p = 0.01). The estimated transfusion-related cost savings were $745/case by acquisition cost and approximately 3- to 5-fold this amount by activity-based cost. The use of RBHS in patients undergoing multilevel spine fusion surgery can conserve blood, promote higher hemoglobin levels, and reduce transfusion-related costs.

First Report of the Resolute Onyx 2.0-mm Zotarolimus-Eluting Stent for the Treatment of Coronary Lesions With Very Small Reference Vessel Diameter.

PubMed

Price, Matthew J; Saito, Shigeru; Shlofmitz, Richard A; Spriggs, Douglas J; Attubato, Michael; McLaurin, Brent; Popma Almonacid, Alexandra; Brar, Sandeep; Liu, Minglei; Moe, Elizabeth; Mehran, Roxana

2017-07-24

The aim of this study was to explore the safety and efficacy of a dedicated drug-eluting stent for the treatment of coronary lesions with very small reference vessel diameter (RVD). Smaller RVD is associated with increased risk for restenosis and target lesion failure (TLF) after stent implantation. This was a prospective, single-arm, multicenter trial of the Resolute Onyx 2.0-mm zotarolimus-eluting stent. The primary endpoint was 12-month TLF, which was compared with a pre-specified performance goal. Subjects with stable or unstable angina or ischemia, target lesions ≤27 mm in length, and RVD ≥2.0 and <2.25 mm were eligible for enrollment. A subset of subjects underwent follow-up angiography at 13 months post-procedure. A total of 101 subjects with 104 lesions were enrolled. The mean age was 67.3 ± 9.6 years, 47% of subjects had diabetes, the mean lesion length was 12.6 ± 6.3 mm, and the mean RVD was 1.91 ± 0.26 mm. The rate of TLF at 12 months was 5.0%, fulfilling the pre-specified performance goal of 19% (p < 0.001). The rates of target lesion revascularization and target vessel myocardial infarction were 2.0% and 3.0%, respectively. There were no episodes of stent thrombosis. In-stent late lumen loss was 0.26 ± 0.48 mm, and the rate of binary restenosis was 12.0%. In this first report of a drug-eluting stent with a dedicated size to treat lesions with RVD <2.25 mm, the Resolute Onyx 2.0-mm zotarolimus-eluting stent was associated with a low rate of TLF and late lumen loss, without a signal for stent thrombosis. This novel-sized drug-eluting stent appears to be a feasible option for the treatment of coronary lesions in extremely small vessels. (Medtronic Resolute Onyx 2.0 mm Clinical Study; NCT02412501). Copyright © 2017 The Authors. Published by Elsevier Inc. All rights reserved.

New generation extracorporeal membrane oxygenation with MedTech Mag-Lev, a single-use, magnetically levitated, centrifugal blood pump: preclinical evaluation in calves.

PubMed

Fujiwara, Tatsuki; Nagaoka, Eiki; Watanabe, Taiju; Miyagi, Naoto; Kitao, Takashi; Sakota, Daisuke; Mamiya, Taichi; Shinshi, Tadahiko; Arai, Hirokuni; Takatani, Setsuo

2013-05-01

We have evaluated the feasibility of a newly developed single-use, magnetically levitated centrifugal blood pump, MedTech Mag-Lev, in a 3-week extracorporeal membrane oxygenation (ECMO) study in calves against a Medtronic Bio-Pump BPX-80. A heparin- and silicone-coated polypropylene membrane oxygenator MERA NHP Excelung NSH-R was employed as an oxygenator. Six healthy male Holstein calves with body weights of about 100 kg were divided into two groups, four in the MedTech group and two in the Bio-Pump group. Under general anesthesia, the blood pump and oxygenator were inserted extracorporeally between the main pulmonary artery and the descending aorta via a fifth left thoracotomy. Postoperatively, both the pump and oxygen flow rates were controlled at 3 L/min. Heparin was continuously infused to maintain the activated clotting time at 200-240 s. All the MedTech ECMO calves completed the study duration. However, the Bio-Pump ECMO calves were terminated on postoperative days 7 and 10 because of severe hemolysis and thrombus formation. At the start of the MedTech ECMO, the pressure drop across the oxygenator was about 25 mm Hg with the pump operated at 2800 rpm and delivering 3 L/min flow. The PO2 of the oxygenator outlet was higher than 400 mm Hg with the PCO2 below 45 mm Hg. Hemolysis and thrombus were not seen in the MedTech ECMO circuits (plasma-free hemoglobin [PFH] < 5 mg/dL), while severe hemolysis (PFH > 20 mg/dL) and large thrombus were observed in the Bio-Pump ECMO circuits. Plasma leakage from the oxygenator did not occur in any ECMO circuits. Three-week cardiopulmonary support was performed successfully with the MedTech ECMO without circuit exchanges. The MedTech Mag-Lev could help extend the durability of ECMO circuits by the improved biocompatible performances. © 2013, Copyright the Authors. Artificial Organs © 2013, International Center for Artificial Organs and Transplantation and Wiley Periodicals, Inc.

Structural deterioration of the Freestyle aortic valve: mode of presentation and mechanisms.

PubMed

Mohammadi, Siamak; Baillot, Richard; Voisine, Pierre; Mathieu, Patrick; Dagenais, François

2006-08-01

Structural valve deterioration is the major cause of bioprosthetic valve failure. Because of the unique design features and anti-calcification treatment of the Freestyle (Medtronic Inc, Minneapolis, Minn) stentless bioprosthesis, development of structural valve deterioration may differ in comparison with other bioprosthetic valves. This study evaluates the mechanisms and clinical presentation of structural valve deterioration in the Freestyle stentless bioprosthesis. Between January 1993 and August 2005, 608 patients underwent aortic valve replacement with a Freestyle stentless bioprosthesis. The implantation technique was subcoronary in 475 patients and a root replacement in 133 patients. Mean overall follow-up was 5.6 +/- 3.4 years. Follow-up was complete in all patients. Clinical and echocardiographic follow-ups were conducted prospectively. Freedom from structural valve deterioration was 95.8% at 10 years. Twelve patients showed evidence of structural valve deterioration and underwent reoperation for aortic regurgitation (n = 10) or aortic stenosis (n = 2). The mean age of patients with structural valve deterioration was significantly lower than patients without structural valve deterioration (62.6 +/- 8.2 years vs 68.6 +/- 8.3 years, P = .02). The median time between implantation and explantation was 8.7 years (range: 1.9-13.3 years). Eleven structural valve deteriorations occurred after subcoronary implantation, and 1 structural valve deterioration occurred after root implantation (P = .4). The mechanisms of structural valve deterioration were leaflet tears in 10 patients (6 in the left coronary cusp and 4 in the right coronary cusp), severe valve calcification in 1 patient, and cusp fibrosis in 1 patient. The interval between onset of symptoms and reoperation was acute or subacute in 10 patients. At 10 years, the Freestyle stentless bioprosthesis shows excellent freedom from structural valve deterioration. Structural valve deterioration in the Freestyle stentless bioprosthesis relates to leaflet tear with minimal calcification in the majority of cases. Because of the fast onset of symptoms with leaflet tear, patients with a Freestyle stentless bioprosthesis should be informed of the preferential mode of failure and time-frame of symptoms.

Smartphones and Programmable Shunts: Are These Indispensable Phones Safe and Smart?

PubMed

Ozturk, Sait; Cakin, Hakan; Kurtuldu, Huseyin; Kocak, Onur; Erol, Fatih S; Kaplan, Metin

2017-06-01

This study aimed to determine whether smartphones affect programmable shunts. iPhone 5S (Apple Inc., Cupertino, CA, USA) and Samsung Galaxy S5 (Samsung Electronics, Gumi, South Korea) smartphones were chosen for this study. For both phones, magnetic field mapping was performed with 3-dimensional magnetic scanning systems constructed with high-precision motorized stages, and a Hall effect sensor was used to measure the flux density on the smartphone surface. The distance (h) between the distal outlet of the reservoir and the rugby ball of the Strata valve (Medtronic Inc., Minneapolis, MN, USA) was measured using highly sensitive microanalysis optical method. During optical microanalysis, while keeping a 3-cm distance between the valve and the magnetic generator, the h value (μm) was recorded for different magnetic flux densities (MFDs). Then, direct x-ray radiography was performed for radiologic assessment after each process under different magnetic fields. For analysis of the Codman Certas valve (Codman Neuro, Raynham, MA, USA), the magnet orientation and the angle between the magnet with the tantalum ball were measured with the same optical analysis. Maximum MFDs found 62 G for iPhone 5S and 61 G for Samsung Galaxy S5. When the magnetic generator formed a current at 0, 30, 60, and 90 G, the h values of the Strata valve adjusted to 100 mm H 2 O opening pressure were 320, 280, 190, and 175 μm, respectively. When the magnetic generator was removed from the environment, the h value returned to 320 μm. In direct graphs taken after each optical analysis at different Gauss values, substitution was not observed at the indicator. The angle in the Codman Certas valve was 123.9°, 112.5°, and 103.6° at the magnetic flux densities of 0, 60, and 90 G, respectively. When the magnetic field was removed (0 G), the angle was still 103.6°, suggesting an irreversible effect in the shunt construct. Smartphones exert reversible effects on Strata programmable valves without producing remarkable radiologic findings and irreversible effects on Codman Certas valves. Copyright © 2017 Elsevier Inc. All rights reserved.

Disposable MagLev centrifugal blood pump utilizing a cone-shaped impeller.

PubMed

Hijikata, Wataru; Sobajima, Hideo; Shinshi, Tadahiko; Nagamine, Yasuyuki; Wada, Suguru; Takatani, Setsuo; Shimokohbe, Akira

2010-08-01

To enhance the durability and reduce the blood trauma of a conventional blood pump with a cone-shaped impeller, a magnetically levitated (MagLev) technology has been applied to the BioPump BPX-80 (Medtronic Biomedicus, Inc., Minneapolis, MN, USA), whose impeller is supported by a mechanical bearing. The MagLev BioPump (MagLev BP), which we have developed, has a cone-shaped impeller, the same as that used in the BPX-80. The suspension and driving system, which is comprised of two degrees of freedom, radial-controlled magnetic bearing, and a simply structured magnetic coupling, eliminates any physical contact between the impeller and the housing. To reduce both oscillation of the impeller and current in the coils, the magnetic bearing system utilizes repetitive and zero-power compensators. In this article, we present the design of the MagLev mechanism, measure the levitational accuracy of the impeller and pressure-flow curves (head-quantity [HQ] characteristics), and describe in vitro experiments designed to measure hemolysis. For the flow-induced hemolysis of the initial design to be reduced, the blood damage index was estimated by using computational fluid dynamics (CFD) analysis. Stable rotation of the impeller in a prototype MagLev BP from 0 to 2750 rpm was obtained, yielding a flow rate of 5 L/min against a head pressure in excess of 250 mm Hg. Because the impeller of the prototype MagLev BP is levitated without contact, the normalized index of hemolysis was 10% less than the equivalent value with the BPX-80. The results of the CFD analysis showed that the shape of the outlet and the width of the fluid clearances have a large effect on blood damage. The prototype MagLev BP satisfied the required HQ characteristics (5 L/min, 250 mm Hg) for extracorporeal circulation support with stable levitation of the impeller and showed an acceptable level of hemolysis. The simulation results of the CFD analysis indicated the possibility of further reducing the blood damage of the prototype MagLev BP.

A Leadless Intracardiac Transcatheter Pacing System.

PubMed

Reynolds, Dwight; Duray, Gabor Z; Omar, Razali; Soejima, Kyoko; Neuzil, Petr; Zhang, Shu; Narasimhan, Calambur; Steinwender, Clemens; Brugada, Josep; Lloyd, Michael; Roberts, Paul R; Sagi, Venkata; Hummel, John; Bongiorni, Maria Grazia; Knops, Reinoud E; Ellis, Christopher R; Gornick, Charles C; Bernabei, Matthew A; Laager, Verla; Stromberg, Kurt; Williams, Eric R; Hudnall, J Harrison; Ritter, Philippe

2016-02-11

A leadless intracardiac transcatheter pacing system has been designed to avoid the need for a pacemaker pocket and transvenous lead. In a prospective multicenter study without controls, a transcatheter pacemaker was implanted in patients who had guideline-based indications for ventricular pacing. The analysis of the primary end points began when 300 patients reached 6 months of follow-up. The primary safety end point was freedom from system-related or procedure-related major complications. The primary efficacy end point was the percentage of patients with low and stable pacing capture thresholds at 6 months (≤2.0 V at a pulse width of 0.24 msec and an increase of ≤1.5 V from the time of implantation). The safety and efficacy end points were evaluated against performance goals (based on historical data) of 83% and 80%, respectively. We also performed a post hoc analysis in which the rates of major complications were compared with those in a control cohort of 2667 patients with transvenous pacemakers from six previously published studies. The device was successfully implanted in 719 of 725 patients (99.2%). The Kaplan-Meier estimate of the rate of the primary safety end point was 96.0% (95% confidence interval [CI], 93.9 to 97.3; P<0.001 for the comparison with the safety performance goal of 83%); there were 28 major complications in 25 of 725 patients, and no dislodgements. The rate of the primary efficacy end point was 98.3% (95% CI, 96.1 to 99.5; P<0.001 for the comparison with the efficacy performance goal of 80%) among 292 of 297 patients with paired 6-month data. Although there were 28 major complications in 25 patients, patients with transcatheter pacemakers had significantly fewer major complications than did the control patients (hazard ratio, 0.49; 95% CI, 0.33 to 0.75; P=0.001). In this historical comparison study, the transcatheter pacemaker met the prespecified safety and efficacy goals; it had a safety profile similar to that of a transvenous system while providing low and stable pacing thresholds. (Funded by Medtronic; Micra Transcatheter Pacing Study ClinicalTrials.gov number, NCT02004873.).

A controlled trial of renal denervation for resistant hypertension.

PubMed

Bhatt, Deepak L; Kandzari, David E; O'Neill, William W; D'Agostino, Ralph; Flack, John M; Katzen, Barry T; Leon, Martin B; Liu, Minglei; Mauri, Laura; Negoita, Manuela; Cohen, Sidney A; Oparil, Suzanne; Rocha-Singh, Krishna; Townsend, Raymond R; Bakris, George L

2014-04-10

Prior unblinded studies have suggested that catheter-based renal-artery denervation reduces blood pressure in patients with resistant hypertension. We designed a prospective, single-blind, randomized, sham-controlled trial. Patients with severe resistant hypertension were randomly assigned in a 2:1 ratio to undergo renal denervation or a sham procedure. Before randomization, patients were receiving a stable antihypertensive regimen involving maximally tolerated doses of at least three drugs, including a diuretic. The primary efficacy end point was the change in office systolic blood pressure at 6 months; a secondary efficacy end point was the change in mean 24-hour ambulatory systolic blood pressure. The primary safety end point was a composite of death, end-stage renal disease, embolic events resulting in end-organ damage, renovascular complications, or hypertensive crisis at 1 month or new renal-artery stenosis of more than 70% at 6 months. A total of 535 patients underwent randomization. The mean (±SD) change in systolic blood pressure at 6 months was -14.13±23.93 mm Hg in the denervation group as compared with -11.74±25.94 mm Hg in the sham-procedure group (P<0.001 for both comparisons of the change from baseline), for a difference of -2.39 mm Hg (95% confidence interval [CI], -6.89 to 2.12; P=0.26 for superiority with a margin of 5 mm Hg). The change in 24-hour ambulatory systolic blood pressure was -6.75±15.11 mm Hg in the denervation group and -4.79±17.25 mm Hg in the sham-procedure group, for a difference of -1.96 mm Hg (95% CI, -4.97 to 1.06; P=0.98 for superiority with a margin of 2 mm Hg). There were no significant differences in safety between the two groups. This blinded trial did not show a significant reduction of systolic blood pressure in patients with resistant hypertension 6 months after renal-artery denervation as compared with a sham control. (Funded by Medtronic; SYMPLICITY HTN-3 ClinicalTrials.gov number, NCT01418261.).

Flow and wall shear stress characterization after endovascular aneurysm repair and endovascular aneurysm sealing in an infrarenal aneurysm model.

PubMed

Boersen, Johannes T; Groot Jebbink, Erik; Versluis, Michel; Slump, Cornelis H; Ku, David N; de Vries, Jean-Paul P M; Reijnen, Michel M P J

2017-12-01

Endovascular aneurysm repair (EVAR) with a modular endograft has become the preferred treatment for abdominal aortic aneurysms. A novel concept is endovascular aneurysm sealing (EVAS), consisting of dual endoframes surrounded by polymer-filled endobags. This dual-lumen configuration is different from a bifurcation with a tapered trajectory of the flow lumen into the two limbs and may induce unfavorable flow conditions. These include low and oscillatory wall shear stress (WSS), linked to atherosclerosis, and high shear rates that may result in thrombosis. An in vitro study was performed to assess the impact of EVAR and EVAS on flow patterns and WSS. Four abdominal aortic aneurysm phantoms were constructed, including three stented models, to study the influence of the flow divider on flow (Endurant [Medtronic, Minneapolis, Minn], AFX [Endologix, Irvine, Calif], and Nellix [Endologix]). Experimental models were tested under physiologic resting conditions, and flow was visualized with laser particle imaging velocimetry, quantified by shear rate, WSS, and oscillatory shear index (OSI) in the suprarenal aorta, renal artery (RA), and common iliac artery. WSS and OSI were comparable for all models in the suprarenal aorta. The RA flow profile in the EVAR models was comparable to the control, but a region of lower WSS was observed on the caudal wall compared with the control. The EVAS model showed a stronger jet flow with a higher shear rate in some regions compared with the other models. Small regions of low WSS and high OSI were found near the distal end of all stents in the common iliac artery compared with the control. Maximum shear rates in each region of interest were well below the pathologic threshold for acute thrombosis. The different stent designs do not influence suprarenal flow. Lower WSS is observed in the caudal wall of the RA after EVAR and a higher shear rate after EVAS. All stented models have a small region of low WSS and high OSI near the distal outflow of the stents. Copyright © 2016 Society for Vascular Surgery. Published by Elsevier Inc. All rights reserved.

Preliminary experience with 4K ultra-high definition endoscope: analysis of pros and cons in skull base surgery.

PubMed

Rigante, M; La Rocca, G; Lauretti, L; D'Alessandris, G Q; Mangiola, A; Anile, C; Olivi, A; Paludetti, G

2017-06-01

During the last two decades endoscopic skull base surgery observed a continuous technical and technological development 3D endoscopy and ultra High Definition (HD) endoscopy have provided great advances in terms of visualisation and spatial resolution. Ultra-high definition (UHD) 4K systems, recently introduced in the clinical practice, will shape next steps forward especially in skull base surgery field. Patients were operated on through transnasal transsphenoidal endoscopic approaches performed using Olympus NBI 4K UHD endoscope with a 4 mm 0° Ultra Telescope, 300 W xenon lamp (CLV-S400) predisposed for narrow band imaging (NBI) technology connected through a camera head to a high-quality control unit (OTV-S400 - VISERA 4K UHD) (Olympus Corporation, Tokyo, Japan). Two screens are used, one 31" Monitor - (LMD-X310S) and one main ultra-HD 55" screen optimised for UHD image reproduction (LMD-X550S). In selected cases, we used a navigation system (Stealthstation S7, Medtronic, Minneapolis, MN, US). We evaluated 22 pituitary adenomas (86.3% macroadenomas; 13.7% microadenomas). 50% were not functional (NF), 22.8% GH, 18.2% ACTH, 9% PRL-secreting. Three of 22 were recurrences. In 91% of cases we achieved total removal, while in 9% near total resection. A mean follow-up of 187 days and average length of hospitalisation was 3.09 ± 0.61 days. Surgical duration was 128.18± 30.74 minutes. We experienced only 1 case of intraoperative low flow fistula with no further complications. None of the cases required any post- or intraoperative blood transfusion. The visualisation and high resolution of the operative field provided a very detailed view of all anatomical structures and pathologies allowing an improvement in safety and efficacy of the surgical procedure. The operative time was similar to the standard 2D HD and 3D procedures and the physical strain was also comparable to others in terms of ergonomics and weight. © Copyright by Società Italiana di Otorinolaringologia e Chirurgia Cervico-Facciale, Rome, Italy.

Single freeze per vein strategy with the second-generation cryoballoon for atrial fibrillation: a propensity score-matched study between 180- and 240-s application time in a large cohort of patients.

PubMed

De Regibus, Valentina; Abugattas, Juan-Pablo; Iacopino, Saverio; Mugnai, Giacomo; Storti, Cesare; Conte, Giulio; Auricchio, Angelo; Ströker, Erwin; Coutiño, Hugo-Enrique; Takarada, Ken; Salghetti, Francesca; Lusoc, Ian; Capulzini, Lucio; Brugada, Pedro; de Asmundis, Carlo; Chierchia, Gian-Battista

2017-11-02

The single-freeze strategy using the second-generation cryoballoon (CB-A, Arctic Front Advance, Medtronic, Minneapolis, MN, USA) has been reported to be as effective as the recommended double-freeze approach in several single-centre studies. In this retrospective, international, multicentre study, we compare the 3-min single-freeze strategy with the 4-min single-freeze strategy. Four hundred and thirty-two patients having undergone pulmonary vein isolation (PVI) by means of CB-A using a single-freeze strategy were considered for this analysis. A cohort of patients who were treated with a 3-min strategy (Group 1) was compared with a propensity score-matched cohort of patients who underwent a 4-min strategy (Group 2). Pulmonary vein isolation was successfully achieved in all the veins using the 28-mm CB-A. The procedural and fluoroscopy times were lower in Group 1 (67.8 ± 17 vs. 73.8 ± 26.3, P < 0.05; 14.9 ± 7.8 vs. 24.2 ± 10.6 min, P < 0.05). The most frequent complication was PNP, with no difference between the two groups (P = 0.67). After a mean follow-up of 13 ± 8 months, taking into consideration a blanking period of 3 months, 85.6% of patients in Group 1 and 87% of patients in Group 2 were free from arrhythmia recurrence at final follow-up (P = 0.67). There is no difference in acute success, rate of complications, and freedom from atrial fibrillation recurrences during the follow-up between 3-min and 4-min per vein freeze strategies. The procedural and fluoroscopy times were significantly shorter in 3-min per vein strategy. Published on behalf of the European Society of Cardiology. All rights reserved. © The Author 2017. For Permissions, please email: journals.permissions@oup.com.

A Randomized Study of SheathLess vs Standard Guiding Catheters for Transradial Percutaneous Coronary Interventions.

PubMed

Noble, Stephane; Tessitore, Elena; Gencer, Baris; Righini, Marc; Robert-Ebadi, Helia; Roffi, Marco; Bonvini, Robert F

2016-12-01

The small diameter of radial arteries remains a major limitation of the transradial approach for percutaneous coronary intervention (PCI). Sheathless guiding catheters (GCs) might offer an advantage over standard GCs. Between 2011 and 2013, we randomized 233 transradial PCIs performed in men with ostial or bifurcation lesions and in all women between standard GC (Medtronic Launcher; Minneapolis, MN) and the SheathLess Eaucath GC (Asahi Intecc, Aichi, Japan). Successful PCI using the transradial approach was not different between the groups (P = 0.74), however the rate of successful transradial PCI with the designated GC (ie, without crossover to the opposing GC) was superior in the SheathLess group compared with the standard GC group (96.5% vs 89.9%; P = 0.047). Safety end point (ie, absence of PCI complication, radial artery occlusion, perforation, pseudoaneurysm, and Early Discharge after Transradial Stenting of Coronary Arteries [EASY] hematoma grade ≥ 2) did not differ between the groups (60.5% in both groups). Mean PCI duration (45.1 minutes vs 45.9 minutes), fluoroscopy (20.1 minutes and 19.9 minutes), and cannulation times (3.6 minutes vs 3.7 minutes), contrast media volume (196 mL vs 187 mL) and conversion to transfemoral approach (1.8% vs 0.8%) were not different between the groups. Patients' subjective assessment revealed less arm pain during navigation of the SheathLess GC (1.9 ± 1.9 vs 4.8 ± 3.6; P < 0.001). Operators graded arm crossability as easier with the SheathLess GC (8.7 ± 1.5 vs 5.1 ± 3.5; P < 0.001). In selected coronary lesions requiring large-bore catheters in men and in all lesions in women, the SheathLess GC was superior to the standard GC for successful transradial PCI with the designated GC. The SheathLess GC was also associated with easier arm navigation and less patient discomfort. Copyright © 2016 Canadian Cardiovascular Society. Published by Elsevier Inc. All rights reserved.

The impact of a low glycemic index (GI) breakfast and snack on daily blood glucose profiles and food intake in young Chinese adult males.

PubMed

Kaur, Bhupinder; Ranawana, Viren; Teh, Ai-Ling; Henry, C Jeya K

2015-09-01

Low glycemic index (GI) foods have been suggested to minimize large fluctuations in blood glucose levels and reduce food intake. However, the majority of studies have been conducted on Caucasian populations with limited data on Asians. The objective of this study was to investigate how the provision of a low GI breakfast and afternoon snack affected daily blood glucose profiles and food intake. In a randomized, controlled crossover non blind design, 11 healthy Chinese male adults (body mass index 22.4 ± 1.3 kg m -2 ) attended two sessions where they consumed either a high or low GI breakfast and afternoon snack, and a standardized buffet lunch. Daily changes in glycemic response (GR) were measured using the Medtronic MiniMed (Northridge, CA) iPro™2 continuous glucose monitoring system (CGMS). The GR was further calculated to obtain the incremental area under the curve (IAUC). Glycemic variability was calculated as mean amplitude of glycemic excursion (MAGE) and energy intake (kcal) was measured quantitatively at the buffet lunch. Compared to the high GI intervention, the low GI intervention significantly reduced the GR following breakfast ( p  = 0.02), lunch ( p  = 0.02) and dinner ( p  = 0.05). The low GI treatment showed a reduction in daily AUC ( p  = 0.03). There was a significant reduction in IAUC after a low GI breakfast compared to the high GI breakfast ( p  = 0.03). The low GI breakfast resulted in a significantly lower food intake at lunch and a resulting decreased energy intake of 285 kcal ( p  = 0.02). The MAGE was significantly lower during the entire low GI treatment ( p  = 0.03). Consumption of a low GI breakfast and afternoon snack was capable of attenuating 24-h blood glucose profiles, minimize glycemic excursions and reduce food intake in healthy Asian males. This simple dietary intervention may be an acceptable approach in improving overall glycemia and energy balance in Asians. NCT02340507.

Simulated ventriculostomy training with conventional neuronavigational equipment used clinically in the operating room: prospective validation study.

PubMed

Kirkman, Matthew A; Muirhead, William; Sevdalis, Nick; Nandi, Dipankar

2015-01-01

Simulation is gaining increasing interest as a method of delivering high-quality, time-effective, and safe training to neurosurgical residents. However, most current simulators are purpose-built for simulation, being relatively expensive and inaccessible to many residents. The purpose of this study was to provide the first comprehensive validity assessment of ventriculostomy performance metrics from the Medtronic StealthStation S7 Surgical Navigation System, a neuronavigational tool widely used in the clinical setting, as a training tool for simulated ventriculostomy while concomitantly reporting on stress measures. A prospective study where participants performed 6 simulated ventriculostomy attempts on a model head with StealthStation-coregistered imaging. The performance measures included distance of the ventricular catheter tip to the foramen of Monro and presence of the catheter tip in the ventricle. Data on objective and self-reported stress and workload measures were also collected. The operating rooms of the National Hospital for Neurology and Neurosurgery, Queen Square, London. A total of 31 individuals with varying levels of prior ventriculostomy experience, varying in seniority from medical student to senior resident. Performance at simulated ventriculostomy improved significantly over subsequent attempts, irrespective of previous ventriculostomy experience. Performance improved whether or not the StealthStation display monitor was used for real-time visual feedback, but performance was optimal when it was. Further, performance was inversely correlated with both objective and self-reported measures of stress (traditionally referred to as concurrent validity). Stress and workload measures were well-correlated with each other, and they also correlated with technical performance. These initial data support the use of the StealthStation as a training tool for simulated ventriculostomy, providing a safe environment for repeated practice with immediate feedback. Although the potential implications are profound for neurosurgical education and training, further research following this proof-of-concept study is required on a larger scale for full validation and proof that training translates into improved long-term simulated and patient outcomes. Copyright © 2015 Association of Program Directors in Surgery. Published by Elsevier Inc. All rights reserved.

Detection of critical cerebral desaturation thresholds by three regional oximeters during hypoxia: a pilot study in healthy volunteers.

PubMed

Tomlin, Kerry L; Neitenbach, Anna-Maria; Borg, Ulf

2017-01-13

Regional oximetry is increasingly used to monitor post-extraction oxygen status of the brain during surgical procedures where hemodynamic fluctuations are expected. Particularly in cardiac surgery, clinicians employ an interventional algorithm to restore baseline regional oxygen saturation (rSO 2 ) when a patient reaches a critical desaturation threshold. Evidence suggests that monitoring cardiac surgery patients and intervening to maintain rSO 2 can improve postoperative outcomes; however, evidence generated with one manufacturer's device may not be applicable to others. We hypothesized that regional oximeters from different manufacturers respond uniquely to changes in oxygen saturation in healthy volunteers. Three devices were tested: INVOS™ 5100C (Medtronic), EQUANOX™ 7600 (Nonin), and FORE-SIGHT™ (CASMED) monitors. We divided ten healthy subjects into two cohorts wearing a single sensor each from INVOS and EQUANOX (n = 6), or INVOS and FORE-SIGHT (n = 4). We induced and reversed hypoxia by adjusting the fraction of inspired oxygen. We calculated the magnitude of absolute rSO 2 change and rate of rSO 2 change during desaturation and resaturation, and determined if and when each device reached a critical interventional rSO 2 threshold during hypoxia. All devices responded to changes in oxygen directionally as expected. The median absolute rSO 2 change and the rate of rSO 2 change was significantly greater during desaturation and resaturation for INVOS compared with EQUANOX (P = 0.04). A similar but nonsignificant trend was observed for INVOS compared with FORE-SIGHT; our study was underpowered to definitively conclude there was no difference. A 10% relative decrease in rSO 2 during desaturation was detected by all three devices across the ten subjects. INVOS met a 20% relative decrease threshold in all subjects of both cohorts, compared to 1 with EQUANOX and 2 with FORE-SIGHT. Neither EQUANOX nor FORE-SIGHT reached a 50% absolute rSO 2 threshold compared with 4 and 3 subjects in each cohort with INVOS, respectively. Significant differences exist between the devices in how they respond to changes in oxygen saturation in healthy volunteers. We suggest caution when applying evidence generated with one manufacturer's device to all devices.

Use of a continuous glucose sensor in an extracorporeal life support circuit.

PubMed

Steil, Garry M; Alexander, Jamin; Papas, Alexandra; Monica, Langer; Modi, Biren P; Piper, Hannah; Jaksic, Tom; Gottlieb, Rebecca; Agus, Michael S D

2011-01-01

Standard care for infants on extracorporeal life support (ECLS) relies on intermittent measurement of blood glucose (BG); however, this can lead to significant changes in BG that go unrecognized for several hours. The present study was designed to assess performance and clinical applicability of a subcutaneous glucose sensor technology modified for use as a blood-contacting sensor within the ECLS circuit. Twelve children, aged 3 years or less, requiring ECLS support were studied. Three continuous glucose sensors (Medtronic MiniMed) were inserted into hubs placed in line with the ECLS circuit. Blood glucose was assessed with a laboratory analyzer (BG(LAB); Bayer Rapidlab 860) approximately every 5 h (mean 4.9 ± 3.3 h) with more frequent samples obtained with a bedside monitor (HemoCue) as needed. Sensor current (I(SIG)) was transmitted to a laptop computer and retrospectively calibrated using BGLAB. Sensor performance was assessed by mean absolute relative difference (MARD), linear regression slope and intercept, and correlation, all with BGLAB as reference. The BGLAB averaged 107.6 ± 36.4 mg/dl (mean ± standard deviation) ranging from 58 to 366 mg/dl. The MARD was 11.4%, with linear regression slope (0.86 ± 0.030) and intercept (9.0 ± 3.2 mg/dl) different from 1 and 0, respectively (p < .05), and correlation (r² = 0.76; p < .001). The system was not associated with any adverse events, and placement and removal into the hubs was easily accomplished. Instances in which more frequent BG values were obtained using a bedside HemoCue (BGHEMO) monitor showed the sensor to respond rapidly to changes. We conclude that continuous sensors can be adapted for use in an ECLS circuit with accuracy similar to or better than that achieved with the subcutaneous site. Continuous glucose monitoring in this population can rapidly detect changes in BG that would not otherwise be observed. Further studies will be needed to assess the benefit of continuous glucose monitoring in this population. © 2010 Diabetes Technology Society.

Big data in wildlife research: remote web-based monitoring of hibernating black bears.

PubMed

Laske, Timothy G; Garshelis, David L; Iaizzo, Paul A

2014-12-11

Numerous innovations for the management and collection of "big data" have arisen in the field of medicine, including implantable computers and sensors, wireless data transmission, and web-based repositories for collecting and organizing information. Recently, human clinical devices have been deployed in captive and free-ranging wildlife to aid in the characterization of both normal physiology and the interaction of animals with their environment, including reactions to humans. Although these devices have had a significant impact on the types and quantities of information that can be collected, their utility has been limited by internal memory capacities, the efforts required to extract and analyze information, and by the necessity to handle the animals in order to retrieve stored data. We surgically implanted miniaturized cardiac monitors (1.2 cc, Reveal LINQ™, Medtronic Inc.), a newly developed human clinical system, into hibernating wild American black bears (N = 6). These devices include wireless capabilities, which enabled frequent transmissions of detailed physiological data from bears in their remote den sites to a web-based data storage and management system. Solar and battery powered telemetry stations transmitted detailed physiological data over the cellular network during the winter months. The system provided the transfer of large quantities of data in near-real time. Observations included changes in heart rhythms associated with birthing and caring for cubs, and in all bears, long periods without heart beats (up to 16 seconds) occurred during each respiratory cycle. For the first time, detailed physiological data were successfully transferred from an animal in the wild to a web-based data collection and management system, overcoming previous limitations on the quantities of data that could be transferred. The system provides an opportunity to detect unusual events as they are occurring, enabling investigation of the animal and site shortly afterwards. Although the current study was limited to bears in winter dens, we anticipate that future systems will transmit data from implantable monitors to wearable transmitters, allowing for big data transfer on non-stationary animals.

"Real life" longevity of implantable cardioverter-defibrillator devices.

PubMed

Manolis, Antonis S; Maounis, Themistoklis; Koulouris, Spyridon; Vassilikos, Vassilios

2017-09-01

Manufacturers of implantable cardioverter-defibrillators (ICDs) promise a 5- to 9-year projected longevity; however, real-life data indicate otherwise. The aim of the present study was to assess ICD longevity among 685 consecutive patients over the last 20 years. Real-life longevity of ICDs may differ from that stated by the manufacturers. The study included 601 men and 84 women (mean age, 63.1 ± 13.3 years). The underlying disease was coronary (n = 396) or valvular (n = 15) disease, cardiomyopathy (n = 220), or electrical disease (n = 54). The mean ejection fraction was 35%. Devices were implanted for secondary (n = 562) or primary (n = 123) prevention. Single- (n = 292) or dual-chamber (n = 269) or cardiac resynchronization therapy (CRT) devices (n = 124) were implanted in the abdomen (n = 17) or chest (n = 668). Over 20 years, ICD pulse generator replacements were performed in 238 patients (209 men; age 63.7 ± 13.9 years; ejection fraction, 37.7% ± 14.0%) who had an ICD for secondary (n = 210) or primary (n = 28) prevention. The mean ICD longevity was 58.3 ± 18.7 months. In 20 (8.4%) patients, devices exhibited premature battery depletion within 36 months. Most (94%) patients had none, minor, or modest use of ICD therapy. Longevity was longest for single-chamber devices and shortest for CRT devices. Latest-generation devices replaced over the second decade lasted longer compared with devices replaced during the first decade. When analyzed by manufacturer, Medtronic devices appeared to have longer longevity by 13 to 18 months. ICDs continue to have limited longevity of 4.9 ± 1.6 years, and 8% demonstrate premature battery depletion by 3 years. CRT devices have the shortest longevity (mean, 3.8 years) by 13 to 17 months, compared with other ICD devices. These findings have important implications, particularly in view of the high expense involved with this type of electrical therapy. © 2017 Wiley Periodicals, Inc.

Stent longitudinal integrity bench insights into a clinical problem.

PubMed

Ormiston, John A; Webber, Bruce; Webster, Mark W I

2011-12-01

Standardized bench-top compression and elongation testing was undertaken to assess the longitudinal strength of contemporary stents. Insights gained may improve clinical stent choice and deployment techniques, and facilitate future stent design improvements. The hoops of coronary stents provide radial support, and connectors hold hoops together. Strut material, shape, and thickness, along with connector number and configuration, provide the balance between stent flexibility and longitudinal integrity. Longitudinal distortion manifests as length change, strut overlap, strut separation, malapposition, and luminal obstruction. These may predispose to restenosis and stent thrombosis, obstruct passage of devices, be misinterpreted as strut fracture, and require additional stenting. The force required to compress and to elongate 7 contemporary stents was measured with an Instron universal testing machine (Norwood, Massachusetts). Stents deployed in a silicone phantom damaged by a balloon or guide catheter were imaged by microcomputed tomography to understand better the appearances and effects of longitudinal distortion. Stents with 2 connectors (Boston Scientific [Natick, Massachusetts] Omega and Medtronic [Santa Rosa, California] Driver) required significantly less force to be compressed up to 5 mm and elongated by 1 mm than designs with more connectors. The 6-connector Cypher Select required significantly more force to be elongated 5 mm than other designs. Stents with 2 connectors between hoops have less longitudinal strength when exposed to compressing or elongating forces than those with more connectors. This independent, standardized study may assist stent selection in clinical situations where longitudinal integrity is important, and may aid future design improvements. Stent longitudinal strength, the resistance to shortening or elongation, appears related to the number of connectors between hoops. Using a standardized testing protocol, designs with 2 connectors were more likely to shorten or elongate than those with more connectors. Distortion may be recognized clinically as bunching or separation of struts, and may be confused with strut fracture. Without post-dilation or further stent deployment, the patient may be at increased risk for adverse clinical events. A stent design change ensuring 3 connectors, especially at the proximal end of a stent, should increase longitudinal integrity, but perhaps at the expense of stent flexibility. Copyright © 2011 American College of Cardiology Foundation. Published by Elsevier Inc. All rights reserved.

PREFACE: Quantum dots as probes in biology

NASA Astrophysics Data System (ADS)

Cieplak, Marek

2013-05-01

The recent availability of nanostructured materials has resulted in an explosion of research focused on their unique optical, thermal, mechanical and magnetic properties. Optical imagining, magnetic enhancement of contrast and drug delivery capabilities make the nanoparticles of special interest in biomedical applications. These materials have been involved in the development of theranostics—a new field of medicine that is focused on personalized tests and treatment. It is likely that multimodal nanomaterials will be responsible for future diagnostic advances in medicine. Quantum dots (QD) are nanoparticles which exhibit luminescence either through the formation of three-dimensional excitons or excitations of the impurities. The excitonic luminescence can be tuned by changing the size (the smaller the size, the higher the frequency). QDs are usually made of semiconducting materials. Unlike fluorescent proteins and organic dyes, QDs resist photobleaching, allow for multi-wavelength excitations and have narrow emission spectra. The techniques to make QDs are cheap and surface modifications and functionalizations can be implemented. Importantly, QDs could be synthesized to exhibit useful optomagnetic properties and, upon functionalization with an appropriate biomolecule, directed towards a pre-selected target for diagnostic imaging and photodynamic therapy. This special issue on Quantum dots in Biology is focused on recent research in this area. It starts with a topical review by Sreenivasan et al on various physical mechanisms that lead to the QD luminescence and on using wavelength shifts for an improvement in imaging. The next paper by Szczepaniak et al discusses nanohybrids involving QDs made of CdSe coated by ZnS and combined covalently with a photosynthetic enzyme. These nanohybrids are shown to maintain the enzymatic activity, however the enzyme properties depend on the size of a QD. They are proposed as tools to study photosynthesis in isolated photosynthetic systems. The next paper, by Olejnik et al, discussed metallic QDs which enhance photosynthetic function in light-harvesting biomolecular complexes. Such hybrid structures with gold QDs are shown to exhibit a strong increase in the fluorescence quantum yield. The next two papers, by Sikora et al and Kaminska et al deal with the ZnO nanoparticles passivated by MgO. In the first of these two papers, the authors describe the behavior of ZnO/MgO when introduced to human cancer cells. In the second, the authors describe the QDs with an extra outer layer of Fe2O3 which makes the nanoparticles superparamagnetic and also capable of generation of reactive oxygen species which could be applied to form localized centers of toxicity for cancer treatment. Finally, in the last paper by Yatsunenko et al, the authors discuss several semiconducting QDs like ZnO with various rare-earth dopands. They propose a microwave-driven hydrothermal technology to make them, characterize their luminescence and demonstrate their usefulness in the early recognition of cancer tissues. Quantum dots as probes in biology contents Quantum dots as probes in biologyMarek Cieplak Luminescent nanoparticles and their applications in the life sciencesVarun K A Sreenivasan, Andrei V Zvyagin and Ewa M Goldys Ferredoxin:NADP+ oxidoreductase in junction with CdSe/ZnS quantum dots: characteristics of an enzymatically active nanohybrid Krzysztof Szczepaniak, Remigiusz Worch and Joanna Grzyb Spectroscopic studies of plasmon coupling between photosynthetic complexes and metallic quantum dotsMaria Olejnik, Bartosz Krajnik, Dorota Kowalska, Guanhua Lin and Sebastian Mackowski Luminescence of colloidal ZnO nanoparticles synthesized in alcohols and biological application of ZnO passivated by MgOBożena Sikora, Krzysztof Fronc, Izabela Kamińska, Kamil Koper, Piotr Stępień and Danek Elbaum Novel ZnO/MgO/Fe2O3 composite optomagnetic nanoparticles I Kamińska, B Sikora, K Fronc, P Dziawa, K Sobczak, R Minikayev, W Paszkowicz and D Elbaum Impact of yttria stabilization on Tb3+ intra-shell luminescence efficiency in zirconium dioxide nanopowdersS Yatsunenko, J Kaszewski, J Grzyb, I Pełech, M M Godlewski, E Mijowska, U Narkiewicz and M Godlewski

Continuous glucose monitoring: a valuable monitoring tool for management of hypoglycemia during chemotherapy for acute lymphoblastic leukemia.

PubMed

Visavachaipan, Nipapat; Aledo, Alexander; Franklin, Bonita H; Brar, Preneet C

2013-01-01

Acute lymphoblastic leukemia (ALL) maintenance therapy (MT) has been occasionally associated with symptomatic hypoglycemia (SH), attributed to purine analog (mercaptopurine [6-MP]). This hypoglycemia has been hypothesized to affect substrate utilization of gluconeogenic precursor alanine in the liver. An overweight 5-year-old boy with ALL was evaluated for SH (lethargy and vomiting) that occurred 8-10 h after fasting while receiving daily 6-MP. Hypoglycemic episodes (>20 episodes per month) occurred predominantly around midmorning but not during the 5-day dexamethasone pulse. The adrenocorticotropic hormone test yielded a normal cortisol response, which ruled out pituitary adrenal suppression. A 12-h overnight fasting glucose was 49 mg/dL, with suppressed insulin response <2 IU/mL, low C-peptide of 0.5 ng/mL, high insulin-like growth factor-binding protein >160 ng/mL, high free fatty acid of 2.64 mmol/L, and negative glucagon stimulation test (change in blood glucose [BG] <5 mg/dL). These results ruled out hyperinsulinism. The patient was placed on cornstarch therapy 5 h prior to dosing with 6-MP. This treatment reduced the SH events to fewer than two episodes per month. To study the efficacy of cornstarch, the patient was fitted with the iPro™ professional continuous glucose monitoring system (CGMS) (Medtronic MiniMed, Northridge, CA) with a preset low alarm at 70 mg/dL, which was worn for a period of 5 days while the patient was on cornstarch. With 1,000 sensor reading the BG range was 65-158 mg/dL, and the percentage mean absolute difference between sensor and finger-stick BG readings (the parent monitored his BG four times a day) was 9.4%. There were no hypoglycemic episodes detected by the CGMS while the patient was on cornstarch. After the cessation of chemotherapy, a 15-h fasting study was performed, and the CGMS was placed. Results showed resolution of hypoglycemia. The CGMS helped us devise an effective management plan for our patient. CGMS proved useful as an adjunct to characterize the pattern of hypoglycemia and to validate the benefit of cornstarch in hypoglycemia associated with 6-MP treatment of ALL.

Early inhibitory effects of zoledronic acid in tooth extraction sockets in dogs are negated by recombinant human bone morphogenetic protein.

PubMed

Gerard, David A; Carlson, Eric R; Gotcher, Jack E; Pickett, David O

2014-01-01

This study was conducted with 2 purposes. The first was to determine the effect of a single dose of zoledronic acid (ZA) on the healing of a tooth extraction socket in dogs. The second was to determine if placement of recombinant human bone morphogenetic protein-2 (rhBMP-2)/absorbable collagen sponge (ACS) - INFUSE, (Medtronic, Memphis, TN) into these extraction sockets would inhibit the inhibition on bone healing and remodeling by ZA. Nine adult female beagle dogs (2 to 3 yr old) were placed into 3 groups of 3 dogs each. Group I received 15 mL of sterile saline intravenously; group II received 2.5 mg of ZA intravenously; and group III received 5 mg of ZA intravenously. Forty-five days after treatment, all dogs underwent extraction of noncontiguous right and left mandibular first molars and second premolars. In group I, the right mandibular extraction sockets had nothing placed in them, whereas the left mandibular sockets had only ACS placed in them. In groups II and III, the right mandibular sockets had rhBMP-2/ACS placed in them, whereas the left mandibular sockets had only ACS placed. All extraction sockets were surgically closed. Tetracycline was given intravenously 5 and 12 days later, and all animals were euthanized 15 days after tooth extraction. The extraction sockets and rib and femur samples were harvested immediately after euthanasia, processed, and studied microscopically. A single dose of ZA significantly inhibited healing and bone remodeling in the area of the tooth extractions. The combination of rhBMP-2/ACS appeared to over-ride some of the bone remodeling inhibition of the ZA and increased bone fill in the extraction sites, and remodeling activity in the area was noted. The effects of rhBMP-2/ACS were confined to the area of the extraction sockets because bone activity at distant sites was not influenced. A single dose of ZA administered intravenously inhibits early healing of tooth extraction sockets and bone remodeling in this animal model. The combination of rhBMP-2/ACS significantly increased bone fill and bone remodeling in these areas, negating much of the effect of the ZA. Copyright © 2014 American Association of Oral and Maxillofacial Surgeons. Published by Elsevier Inc. All rights reserved.

Long-term results of Talent endografts for endovascular abdominal aortic aneurysm repair.

PubMed

Verhoeven, Bart A N; Waasdorp, Evert J; Gorrepati, Madhu L; van Herwaarden, Joost A; Vos, Jan Albert; Wille, Jan; Moll, Frans L; Zarins, Christopher K; de Vries, Jean Paul P M

2011-02-01

Since the introduction of endovascular aneurysm repair (EVAR), long-term follow-up studies reporting single-device results are scarce. In this study, we focus on EVAR repair with the Talent stent graft (Medtronic, Santa Rosa, Calif). Between July 2000 and December 2007, 365 patients underwent elective EVAR with a Talent device. Patient data were gathered prospectively and evaluated retrospectively. By American Society of Anesthesiologists category, 74% were categories III and IV. Postoperative computed tomography (CT) scanning was performed before discharge, at 3, 12 months, and yearly thereafter. Data are presented according to reporting standards for EVAR. The mean proximal aortic neck diameter was 27 mm (range, 16-36 mm), with a neck length <15 mm in 31% (data available for 193 patients). Deployment of endografts was successful in 361 of 365 patients (99%). Initially, conversion to laparotomy was necessary in four patients. Primary technical success determined by results from computed tomography (CT) scans before discharge was achieved in 333 patients (91%). Proximal type I endoleaks were present in 28 patients (8%) during follow-up, and 14 of these patients needed additional treatment for type I endoleak. The 30-day mortality for the whole Talent group was 1.1% (4 of 365). Follow-up to 84 months is reported for 24 patients. During follow-up, 122 (33%) patients died; in nine, death was abdominal aortic aneurysm (AAA)-related (including 30-day mortality). Kaplan-Meier estimates revealed primary clinical success rates of 98% at 1 year, 93% at 2 years, 88% at 3 years, 79% at 4 years, 64% at 5 years, 51% at 6 years, and 48% at 7 years. Secondary interventions were performed in 73 of 365 patients (20%). Ten conversions for failed endografts were performed. Life-table yearly risk for AAA-related reintervention was 6%, yearly risk for conversion to open repair was 1.1%, yearly risk for total mortality was 8.9%, and yearly risk for AAA-related mortality was 0.8%. Initially, technical success of endovascular aneurysm repair (EVAR) using the Talent endograft is high, with acceptable yearly risk for AAA-related mortality and conversion. However, a substantial amount of mainly endovascular reinterventions is necessary during long-term follow-up to achieve these results. Copyright © 2011 Society for Vascular Surgery. All rights reserved.

Comparison between skin-mounted fiducials and bone-implanted fiducials for image-guided neurosurgery

NASA Astrophysics Data System (ADS)

Rost, Jennifer; Harris, Steven S.; Stefansic, James D.; Sillay, Karl; Galloway, Robert L., Jr.

2004-05-01

Point-based registration for image-guided neurosurgery has become the industry standard. While the use of intrinsic points is appealing because of its retrospective nature, affixing extrinsic objects to the head prior to scanning has been demonstrated to provide much more accurate registrations. Points of reference between image space and physical space are called fiducials. The extrinsic objects which generate those points are fiducial markers. The markers can be broken down into two classifications: skin-mounted and bone-implanted. Each has distinct advantages and disadvantages. Skin-mounted fiducials require simply sticking them on the patient in locations suggested by the manufacturer, however, they can move with tractions placed on the skin, fall off and perhaps the most dangerous problem, they can be replaced by the patient. Bone implanted markers being rigidly affixed to the skull do not present such problems. However, a minor surgical intervention (analogous to dental work) must be performed to implant the markers prior to surgery. Therefore marker type and use has become a decision point for image-guided surgery. We have performed a series of experiments in an attempt to better quantify aspects of the two types of markers so that better informed decisions can be made. We have created a phantom composed of a full-size plastic skull [Wards Scientific Supply] with a 500 ml bag of saline placed in the brain cavity. The skull was then sealed. A skin mimicking material, DragonSkinTM [SmoothOn Company] was painted onto the surface and allowed to dry. Skin mounted fiducials [Medtronic-SNT] and bone-implanted markers [Z-Kat]were placed on the phantom. In addition, three additional bone-implanted markers were placed (two on the base of the skull and one in the eye socket for use as targets). The markers were imaged in CT and 4 MRI sequences (T1-weighted, T2 weighted, SPGR, and a functional series.) The markers were also located in physical space using an Optotrak 3020 [Northern Digital Inc]. Registrations between image space and physical space were performed and fiducial and target registration errors were determined. Finally the 5 bone-implanted makers which penetrated the skin were removed and a traction equivalent to 25% of the weight of the average human head was applied to the "skin" surface. Target and fiducial registrations were again performed.

Solubility and Stability of Baclofen 3 mg/mL Intrathecal Formulation and Its Compatibility With Implantable Programmable Intrathecal Infusion Systems.

PubMed

Yue, Baohua; Brendel, Ron; Lukitsch, Amelia; Prentice, Thomas; Doty, Brian

2017-06-01

Commercial baclofen formulations used with infusion pumps are available at therapeutic concentrations of 0.5-2.0 mg/mL. However, patients who receive higher daily doses of baclofen may benefit from products with greater baclofen concentrations since their refill frequency would be reduced (up to a maximum of 180 days). We evaluated baclofen solubility, baclofen 3 mg/mL intrathecal (IT) formulation stability, and chemical and physical compatibility with Medtronic SynchroMed ® II and Codman Medstream ® programmable IT infusion pumps. For solubility evaluations, baclofen powder was dissolved into isotonic saline and tested at 5°C, 25°C, and 40°C. To demonstrate drug product stability, both physical and chemical stability attributes of baclofen 3 mg/mL in prefilled syringes were evaluated over 36 months with storage at 25°C. For a simulated in-use stability (compatibility) study, a 3 mg/mL baclofen IT formulation was placed in SynchroMed II and Codman Medstream pumps at 37ºC for study durations, and evaluated at different flow rates. Pump effluent was collected at various times and analyzed by high-performance liquid chromatography for baclofen content. On completion of the in-use stability study, pumps exposed to baclofen 3 mg/mL were dissected and visually evaluated for signs of deterioration. Baclofen solubility was found to be 3.2 mg/mL at 5°C, 3.6 mg/mL at 25°C, and 3.9 mg/mL at 40°C. During the 36-month stability study of prefilled syringes stored at 25°C, baclofen content remained unchanged and no precipitation was observed. The simulated in-use pump study performed at 37ºC showed that a baclofen 3 mg/mL IT formulation was stable at different flow rates and throughout different expected residence times for both pump models. Components from both pumps exhibited no noticeable deterioration after exposure to the 3 mg/mL formulation. Baclofen 3 mg/mL IT formulation was stable during long-term storage at 25°C and remained stable under conditions matching those encountered in clinical practice (37°C). © 2016 International Neuromodulation Society.

Anatomical and procedural determinants of ambulatory blood pressure lowering following catheter-based renal denervation using radiofrequency.

PubMed

Lauder, Lucas; Ewen, Sebastian; Tzafriri, Abraham R; Edelman, Elazer R; Cremers, Bodo; Kulenthiran, Saarraaken; Ukena, Christian; Linz, Dominik; Kindermann, Ingrid; Tsioufis, Costas; Scheller, Bruno; Böhm, Michael; Mahfoud, Felix

2018-03-02

Catheter-based renal sympathetic denervation (RDN) has been introduced to lower blood pressure (BP) and sympathetic activity in patients with uncontrolled hypertension with at best equivocal results. It has been postulated that anatomic and procedural elements introduce unaccounted variability and yet little is known of the impact of renal anatomy and procedural parameters on BP response to RDN. Anatomical parameters such as length and diameter were analyzed by quantitative vascular analysis and the prevalence of accessory renal arteries and renal artery disease were documented in 150 patients with resistant hypertension undergoing bilateral RDN using a mono-electrode radiofrequency catheter (Symplicity Flex, Medtronic). Accessory renal arteries and renal artery disease were present in 56 (37%) and 14 patients (9%), respectively. At 6-months, 24 h-ambulatory BP was reduced by 11/6 mm Hg (p < 0.001 for both). Change of systolic blood pressure (SBP) was not related to the presence of accessory renal arteries (p = 0.543) or renal artery disease (p = 0.598). Patients with at least one main renal artery diameter ≤ 4 mm had a more pronounced reduction of 24 h-ambulatory SBP compared to patients where both arteries were >4 mm (-19 vs. -10 mmHg; p = 0.038). Neither the length of the renal artery nor the number of RF ablations influenced 24 h-ambulatory BP reduction at 6 months. 24 h-ambulatory BP lowering was most pronounced in patients with smaller renal artery diameter but not related to renal artery length, accessory arteries or renal artery disease. Further, there was no dose-response relationship observed with increasing number of ablations. Because little is known of the impact of renal anatomy and procedural parameters on blood pressure (BP) response to renal denervation (RDN), anatomical and procedural data were analyzed in 150 patients undergoing bilateral RDN. BP lowering was most pronounced in patients with smaller renal artery diameter but not related to renal artery length, the presence of renal artery disease or accessory renal arteries. Further, there was no dose-response relationship observed with increasing number of ablations. Copyright © 2018. Published by Elsevier Inc.

Evaluating the accuracy, reliability, and clinical applicability of continuous glucose monitoring (CGM): Is CGM ready for real time?

PubMed

Mazze, Roger S; Strock, Ellie; Borgman, Sarah; Wesley, David; Stout, Philip; Racchini, Joel

2009-01-01

This study was designed to assess the accuracy, reliability, and contribution to clinical decision-making of two commercially available continuous glucose monitoring (CGM) devices using a novel analytical approach. Eleven individuals with type 1 diabetes and five with type 2 diabetes wore a Guardian RT (GRT) (Medtronic Minimed, Northridge, CA) or DexCom STS Continuous Monitoring System (DEX) (San Diego, CA) device for 200 h followed by an 8-h laboratory study. A subset of these subjects wore both devices simultaneously. Subjects produced 1,902 +/- 269 readings during the ambulatory phase. During the laboratory study we found: lag time of 21 +/- 5 min for GRT and 7 +/- 7 min for DEX (P < 0.005); mean absolute relative difference of 19.9% and 16.7%, respectively, for GRT and DEX; and glucose exposure (the ratio of study device/laboratory reference device [YSI Instruments, Inc., Yellow Springs, OH] area under the curve) of 95 +/- 6% for GRT and 101 +/- 13% for DEX. Reliability measured during laboratory study showed 82% for DEX and 99% for GRT. Clarke Error Grid analysis (YSI reference) showed for GRT 59% of values in zone A, 34% in zone B, and 7% in zone D and for DEX 70% in zone A, 28% in zone B, 1% in zone C, and 1% in zone D. Bland-Altman plots (YSI standard) yielded for DEX 3 mg/dL (95% confidence interval, -78 to 84 mg/dL) and for GRT -21 mg/dL (95% confidence interval, -124 to 82 mg/dL). Six of eight subjects completed both home and laboratory simultaneous use of DEX and GRT. Lag times were inconsistent between devices, ranging from 0 to 32 min; area under the curve revealed a tendency for DEX to report higher total glucose exposure than GRT for the same patient. CGM detects abnormalities in glycemic control in a manner heretofore impossible to obtain. However, our studies revealed sufficient incongruence between simultaneous laboratory blood glucose levels and interstitial fluid glucose (after calibrations) to question the fundamental assumption that interstitial fluid glucose and blood glucose could be made identical by resorting to algorithms based on concurrent blood glucose levels alone.

Long-term efficacy and safety of sacral nerve stimulation for fecal incontinence.

PubMed

Mellgren, Anders; Wexner, Steven D; Coller, John A; Devroede, Ghislain; Lerew, Darin R; Madoff, Robert D; Hull, Tracy

2011-09-01

Sacral nerve stimulation is effective in the treatment of urinary incontinence and is currently under Food and Drug Administration review in the United States for fecal incontinence. Previous reports have focused primarily on short-term results of sacral nerve stimulation for fecal incontinence. The present study reports the long-term effectiveness and safety of sacral nerve stimulation for fecal incontinence in a large prospective multicenter study. Patients with fecal incontinent episodes more than twice per week were offered participation in this multicentered prospective trial. Patients showing ≥ 50% improvement during test stimulation were offered chronic implantation of the InterStim Therapy system (Medtronic; Minneapolis, MN). The aims of the current report were to provide 3-year follow-up data on patients from that study who underwent sacral nerve stimulation and were monitored under the rigors of an Food and Drug Administration-approved investigational protocol. One hundred thirty-three patients underwent test stimulation with a 90% success rate, of whom 120 (110 females) with a mean age of 60.5 years and a mean duration of fecal incontinence of 7 years received chronic implantation. Mean length of follow-up was 3.1 (range, 0.2-6.1) years, with 83 patients completing all or part of the 3-year follow-up assessment. At 3 years follow-up, 86% of patients (P < .0001) reported ≥ 50% reduction in the number of incontinent episodes per week compared with baseline and the number of incontinent episodes per week decreased from a mean of 9.4 at baseline to 1.7. Perfect continence was achieved in 40% of subjects. The therapy also improved the fecal incontinence severity index. Sacral nerve stimulation had a positive impact on the quality of life, as evidenced by significant improvements in all 4 scales of the Fecal Incontinence Quality of Life instrument at 12, 24, and 36 months of follow-up. The most common device- or therapy-related adverse events through the mean 36 months of follow-up included implant site pain (28%), paresthesia (15%), change in the sensation of stimulation (12%), and infection (10%). There were no reported unanticipated adverse device effects associated with sacral nerve stimulation therapy. Sacral nerve stimulation using InterStim Therapy is a safe and effective treatment for patients with fecal incontinence. These data support long-term safety and effectiveness to 36 months.

Endovascular aneurysm repair simulation can lead to decreased fluoroscopy time and accurately delineate the proximal seal zone.

PubMed

Kim, Ann H; Kendrick, Daniel E; Moorehead, Pamela A; Nagavalli, Anil; Miller, Claire P; Liu, Nathaniel T; Wang, John C; Kashyap, Vikram S

2016-07-01

The use of simulators for endovascular aneurysm repair (EVAR) is not widespread. We examined whether simulation could improve procedural variables, including operative time and optimizing proximal seal. For the latter, we compared suprarenal vs infrarenal fixation endografts, right femoral vs left femoral main body access, and increasing angulation of the proximal aortic neck. Computed tomography angiography was obtained from 18 patients who underwent EVAR at a single institution. Patient cases were uploaded to the ANGIO Mentor endovascular simulator (Simbionix, Cleveland, Ohio) allowing for three-dimensional reconstruction and adapted for simulation with suprarenal fixation (Endurant II; Medtronic Inc, Minneapolis, Minn) and infrarenal fixation (C3; W. L. Gore & Associates Inc, Newark, Del) deployment systems. Three EVAR novices and three experienced surgeons performed 18 cases from each side with each device in randomized order (n = 72 simulations/participant). The cases were stratified into three groups according to the degree of infrarenal angulation: 0° to 20°, 21° to 40°, and 41° to 66°. Statistical analysis used paired t-test and one-way analysis of variance. Mean fluoroscopy time for participants decreased by 48.6% (P < .0001), and total procedure time decreased by 33.8% (P < .0001) when initial cases were compared with final cases. When stent deployment accuracy was evaluated across all cases, seal zone coverage in highly angulated aortic necks was significantly decreased. The infrarenal device resulted in mean aortic neck zone coverage of 91.9%, 89.4%, and 75.4% (P < .0001 by one-way analysis of variance), whereas the suprarenal device yielded 92.9%, 88.7%, and 71.5% (P < .0001) for the 0° to 20°, 21° to 40°, and 41° to 66° cases, respectively. Suprarenal fixation did not increase seal zone coverage. The side of femoral access for the main body did not influence proximal seal zone coverage regardless of infrarenal angulation. Simulation of EVAR leads to decreased fluoroscopy times for novice and experienced operators. Side of femoral access did not affect precision of proximal endograft landing. The angulated aortic neck leads to decreased proximal seal zone coverage regardless of infrarenal or suprarenal fixation devices. Copyright © 2016 Society for Vascular Surgery. Published by Elsevier Inc. All rights reserved.

Allogeneic mesenchymal precursor cells (MPCs) combined with an osteoconductive scaffold to promote lumbar interbody spine fusion in an ovine model.

PubMed

Wheeler, Donna L; Fredericks, Douglas C; Dryer, Randall F; Bae, Hyun W

2016-03-01

Advances in immunomagnetic cell sorting have enabled isolation and purification of pleuripotent stem cells from marrow aspirates and have expanded stem cell therapies to include allogeneic sources. This study aimed to determine the safety and efficacy of allogeneic mesenchymal precursor cells (MPCs) combined with an osteoconductive scaffold in lumbar interbody spinal fusion using an ovine model. Thirty-two skeletally mature ewes underwent a single-level interbody fusion procedure using a Polyetheretherketone fusion cage supplemented with either iliac crest autograft (AG) or an osteconductive scaffold (Mastergraft Matrix, Medtronic, Memphis, TN, USA) with 2.5×10(6) MPCs, 6.25×10(6) MPCs, or 12.5×10(6) MPCs. Plain radiographs and computed tomography scans were scored for bridging bone at multiple points during healing and at necropsy. The biomechanical competency of fusion was scored by manual palpation and quantified using functional radiographs at necropsy. Postnecropsy histopathology and histomorphometric analysis assessed the local response to MPC treatment and quantified the volume and connectivity of newly formed bridging bone. Safety was assessed by serum biochemistry, hematology, and organ histopathology. Mesenchymal precursor cell treatment caused no adverse systemic or local tissue responses. All analyses indicated MPCs combined with an osteoconductive scaffold achieved similar or better fusion success as AG treatment after 16 weeks, and increasing the MPC dose did not enhance fusion. Manual palpation of the fusion site indicated more than 75% of MPC-treated and 65% of AG-treated animals achieved rigid fusion, which was corroborated with functional radiography. Computed tomography fusion scores indicated all animals in the MPC- and AG-treatment groups were fused at 16 weeks, yet X-ray scores indicated only 67% of the AG-treated animals were fused. Histomorphometry analyses showed equivalent outcomes for fusion connectivity and bony fusion area for MPC- and AG-treated groups. Approximately 6% residual graft material remained in the MPC-treated fusion sites at 16 weeks. Adult allogeneic MPCs delivered using an osteoconductive scaffold were both safe and efficacious in this ovine spine interbody fusion model. These results support the use ofallogeneic MPCs as an alternative to AG for lumbar interbody spinal fusion procedures. Copyright © 2016 Elsevier Inc. All rights reserved.

Reduction of inappropriate anti-tachycardia pacing therapies and shocks by a novel suite of detection algorithms in heart failure patients with cardiac resynchronization therapy defibrillators: a historical comparison of a prospective database.

PubMed

Lunati, Maurizio; Proclemer, Alessandro; Boriani, Giuseppe; Landolina, Maurizio; Locati, Emanuela; Rordorf, Roberto; Daleffe, Elisabetta; Ricci, Renato Pietro; Catanzariti, Domenico; Tomasi, Luca; Gulizia, Michele; Baccillieri, Maria Stella; Molon, Giulio; Gasparini, Maurizio

2016-09-01

Implantable cardioverter defibrillators improve survival of patients at risk for ventricular arrhythmias, but inappropriate shocks occur in up to 30% of patients and have been associated with worse quality of life and prognosis. In heart failure patients with cardiac resynchronization therapy defibrillators (CRT-Ds), we evaluated whether a new generation of detection and discrimination algorithms reduces inappropriate shocks. We analysed 1983 Medtronic CRT-D patients (80% male, 67 ± 10 years), 1368 with standard devices (Control CRT-D) and 615 with new generation devices (New CRT-D). Expert electrophysiologists reviewed and classified the electrograms of all device-detected ventricular tachycardia/fibrillation episodes. Total follow-up was 3751 patients-years. Incidence of inappropriate shocks at 1 year was 2.8% [95% confidence interval (CI) = 2.0-3.5] in Control CRT-D and 0.9% (CI = 0.4-2.2) in New CRT-D (hazard ratio = 0.37, CI = 0.21-0.66, P < 0.001). In New CRT-D, inappropriate shocks were reduced by 77% [incidence rate ratio (IRR) = 0.23, CI = 0.16-0.35, P < 0.001] and inappropriate anti-tachycardia pacing by 81% (IRR = 0.19, CI = 0.11-0.335, P < 0.001). Annual rate per 100 patient-years for appropriate VF detections was 3.0 (CI = 2.1-4.2) in New CRT-D and 3.2 (CI = 2.1-5.0) in Control CRT-D (P = 0.68), for syncope was 0.4 (CI = 0.2-0.9) in New CRT-D and 0.7 (CI = 0.5-1.0) in Control CRT-D (P = 0.266), and for death was 1.0 (CI = 0.6-1.6) in New CRT-D and 3.5 (CI = 3.0-4.1) in Control CRT-D (P < 0.001). Detection and discrimination algorithms used in new generation CRT-D significantly reduced inappropriate shocks when compared with standard CRT-D. This result, with no compromise on VF sensitivity or risk of syncope, has important implications for patients' quality of life and prognosis. Published on behalf of the European Society of Cardiology. All rights reserved. © The Author 2016. For permissions please email: journals.permissions@oup.com.

Benchtop quantification of gutter formation and compression of chimney stent grafts in relation to renal flow in chimney endovascular aneurysm repair and endovascular aneurysm sealing configurations.

PubMed

Boersen, Johannes T; Donselaar, Esme J; Groot Jebbink, Erik; Starreveld, Roeliene; Overeem, Simon P; Slump, Cornelis H; de Vries, Jean-Paul P M; Reijnen, Michel M P J

2017-11-01

The chimney technique has been successfully used to treat juxtarenal aortic aneurysms. The two main issues with this technique are gutter formation and chimney graft (CG) compression, which induce a risk for type Ia endoleaks and stent thrombosis, respectively. In this benchtop study, the geometry and renal artery flow of chimney endovascular aneurysm repair configurations were compared with chimney configurations with endovascular aneurysm sealing (ch-EVAS). Seven flow phantoms were constructed, including one control and six chimney endovascular aneurysm repairs (Endurant [Medtronic Inc, Minneapolis, Minn] and AFX [Endologix Inc, Irvine, Calif]) or ch-EVAS (Nellix, Endologix) configurations, combined with either balloon-expandable or self-expanding CGs with an intended higher positioning of the right CG in comparison to the left CG. Geometric analysis was based on measurements at three-dimensional computed tomography angiography and included gutter volume and CG compression, quantified by the ratio between maximal and minimal diameter (D-ratio). In addition, renal artery flow was studied in a physiologic flow model and compared with the control. The average gutter volume was 343.5 ± 142.0 mm 3 , with the lowest gutter volume in the EVAS-Viabahn (W. L. Gore & Associates, Flagstaff, Ariz) combination (102.6 mm 3 ) and the largest in the AFX-Advanta V12 (Atrium Medical Corporation, Hudson, NH) configuration (559.6 mm 3 ). The maximum D-ratio was larger in self-expanding CGs than in balloon-expandable CGs in all configurations (2.02 ± 0.34 vs 1.39 ± 0.13). The CG compression had minimal influence on renal volumetric flow (right, 390.7 ± 29.4 mL/min vs 455.1 mL/min; left, 423.9 ± 28.3 mL/min vs 410.0 mL/min in the control). This study showed that gutter volume was lowest in ch-EVAS in combination with a Viabahn CG. CG compression was lower in configurations with the Advanta V12 than with Viabahn. Renal flow is unrestricted by CG compression. Copyright © 2016 Society for Vascular Surgery. Published by Elsevier Inc. All rights reserved.

In vitro performance and principles of anti-siphoning devices.

PubMed

Freimann, Florian Baptist; Kimura, Takaoki; Stockhammer, Florian; Schulz, Matthias; Rohde, Veit; Thomale, Ulrich-Wilhelm

2014-11-01

Anti-siphon devices (ASDs) of various working principles were developed to overcome overdrainage-related complications associated with ventriculoperitoneal shunting. We aimed to provide comparative data on the pressure and flow characteristics of six different types of ASDs (gravity-assisted, membrane-controlled, and flow-regulated) in order to achieve a better understanding of these devices and their potential clinical application. We analyzed three gravity-dependent ASDs (ShuntAssistant [SA], Miethke; Gravity Compensating Accessory [GCA], Integra; SiphonX [SX], Sophysa), two membrane-controlled ASDs (Anti-Siphon Device [IASD], Integra; Delta Chamber [DC], Medtronic), and one flow-regulated ASD (SiphonGuard [SG], Codman). Defined pressure conditions within a simulated shunt system were generated (differential pressure 10-80 cmH2O), and the specific flow and pressure characteristics were measured. In addition, the gravity-dependent ASDs were measured in defined spatial positions (0-90°). The flow characteristics of the three gravity-assisted ASDs were largely dependent upon differential pressure and on their spatial position. All three devices were able to reduce the siphoning effect, but each to a different extent (flow at inflow pressure: 10 cmH2O, siphoning -20 cmH2O at 0°/90°: SA, 7.1 ± 1.2*/2.3 ±  0.5* ml/min; GCA, 10.5 ± 0.8/3.4 ± 0.4* ml/min; SX, 9.5 ± 1.2*/4.7 ± 1.9* ml/min, compared to control, 11.1 ± 0.4 ml/min [*p < 0.05]). The flow characteristics of the remaining ASDs were primarily dependent upon the inflow pressure effect (flow at 10 cmH2O, siphoning 0 cmH2O/ siphoning -20cmH2O: DC, 2.6 ± 0.1/ 4 ± 0.3* ml/min; IASD, 2.5 ± 0.2/ 0.8 ± 0.4* ml/min; SG, 0.8 ± 0.2*/ 0.2 ± 0.1* ml/min [*p < 0.05 vs. control, respectively]). The tested ASDs were able to control the siphoning effect within a simulated shunt system to differing degrees. Future comparative trials are needed to determine the type of device that is superior for clinical application.

Alarms based on real-time sensor glucose values alert patients to hypo- and hyperglycemia: the guardian continuous monitoring system.

PubMed

Bode, Bruce; Gross, Kenneth; Rikalo, Nancy; Schwartz, Sherwyn; Wahl, Timothy; Page, Casey; Gross, Todd; Mastrototaro, John

2004-04-01

The purposes of this study were to demonstrate the accuracy and effectiveness of the Guardian Continuous Monitoring System (Medtronic MiniMed, Northridge, California) and to demonstrate that the application of real-time alarms to continuous monitoring alerts users to hypo and hyperglycemia and reduces excursions in people with diabetes. A total of 71 subjects with type 1 diabetes, mean hemoglobin A1c of 7.6 +/- 1.1%, age 44.0 +/- 11.4 years, and duration of diabetes 23.6 +/- 10.6 years were enrolled in this two-period, randomized, multicenter study. Subjects were randomized into either an Alert group or a Control group. The accuracy of the Guardian was evaluated by treating the study data as a single-sample correlational design. Effectiveness of the Guardian alerts was evaluated by comparing the Alert group with the Control group. The mean (median) absolute relative error between home blood glucose meter readings and sensor values was 21.3% (17.3%), and the Guardian, on average, read 12.8 mg/dL below the concurrent home blood glucose meter readings. The hypoglycemia alert was able to distinguished glucose values < or =70 mg/dL with 67% sensitivity, 90% specificity, and 47% false alerts. The hyperglycemia alert showed a similar ability to detect sensor values > or =250 mg/dL with 63% sensitivity, 97% specificity, and 19% false alerts. The Alert group demonstrated a median decrease in the duration of hypoglycemic excursions (-27.8 min) that was significantly greater than the median decrease in the duration of hypoglycemic excursions in the Control group (-4.5 min) (P = 0.03). A marginally significant increase in the frequency of hyperglycemic excursions (P = 0.07) between Period 1 and Period 2 was accompanied by a decrease of 9.6 min in the duration of hyperglycemic excursions in the Alert group. Glucose measurements differ between blood samples taken from the finger and interstitial fluid, especially when levels are changing rapidly; however, these results demonstrate that the Guardian is reasonably accurate while performing continuous glucose monitoring. The subjects' responses to hypoglycemia alerts resulted in a significant reduction in the duration of hypoglycemic excursions; however, overtreating hypoglycemia may have resulted in a marginally significant increase in the frequency of hyperglycemic excursions.

1-Year Outcomes After Transcatheter Aortic Valve Replacement With Balloon-Expandable Versus Self-Expandable Valves: Results From the CHOICE Randomized Clinical Trial.

PubMed

Abdel-Wahab, Mohamed; Neumann, Franz-Josef; Mehilli, Julinda; Frerker, Christian; Richardt, Doreen; Landt, Martin; Jose, John; Toelg, Ralph; Kuck, Karl-Heinz; Massberg, Steffen; Robinson, Derek R; El-Mawardy, Mohamed; Richardt, Gert

2015-08-18

The use of a balloon-expandable transcatheter heart valve previously resulted in a greater rate of device success compared with a self-expandable transcatheter heart valve. The aim of this study was to evaluate clinical and echocardiographic outcome data at longer term follow-up. The investigator-initiated trial randomized 241 high-risk patients with symptomatic severe aortic stenosis and anatomy suitable for treatment with both balloon- and self-expandable transcatheter heart valves to transfemoral transcatheter aortic valve replacement with either device. Patients were followed-up for 1 year, with assessment of clinical outcomes and echocardiographic evaluation of valve function. At 1 year, the rates of death of any cause (17.4% vs. 12.8%; relative risk [RR]: 1.35; 95% confidence interval [CI]: 0.73 to 2.50; p = 0.37) and of cardiovascular causes (12.4% vs. 9.4%; RR: 1.32; 95% CI: 0.63 to 2.75; p = 0.54) were not statistically significantly different in the balloon- and self-expandable groups, respectively. The frequencies of all strokes (9.1% vs. 3.4%; RR: 2.66; 95% CI: 0.87 to 8.12; p = 0.11) and repeat hospitalization for heart failure (7.4% vs. 12.8%; RR: 0.58; 95% CI: 0.26 to 1.27; p = 0.19) did not statistically significantly differ between the 2 groups. Elevated transvalvular gradients during follow-up were observed in 4 patients in the balloon-expandable group (3.4% vs. 0%; p = 0.12); all were resolved with anticoagulant therapy, suggesting a thrombotic etiology. More than mild paravalvular regurgitation was more frequent in the self-expandable group (1.1% vs. 12.1%; p = 0.005). Despite the higher device success rate with the balloon-expandable valve, 1-year follow-up of patients in CHOICE (Randomized Comparison of Transcatheter Heart Valves in High Risk Patients With Severe Aortic Stenosis: Medtronic CoreValve Versus Edwards SAPIEN XT Trial), with limited statistical power, revealed clinical outcomes after transfemoral transcatheter aortic valve replacement with both balloon- and self-expandable prostheses that were not statistically significantly different. (A Comparison of Transcatheter Heart Valves in High Risk Patients With Severe Aortic Stenosis: The CHOICE Trial; NCT01645202). Copyright © 2015 American College of Cardiology Foundation. Published by Elsevier Inc. All rights reserved.

Effectiveness and harms of recombinant human bone morphogenetic protein-2 in spine fusion: a systematic review and meta-analysis.

PubMed

Fu, Rongwei; Selph, Shelley; McDonagh, Marian; Peterson, Kimberly; Tiwari, Arpita; Chou, Roger; Helfand, Mark

2013-06-18

Recombinant human bone morphogenetic protein-2 (rhBMP-2) is used as a bone graft substitute in spinal fusion, which unites (fuses) bones in the spine. The accuracy and completeness of journal publications of industry-sponsored trials on the effectiveness and harms of rhBMP-2 has been called into question. To independently assess the effectiveness and harms of rhBMP-2 in spinal fusion and reporting bias in industry-sponsored journal publications. Individual-patient data (IPD) from 17 industry-sponsored studies; related internal documents; and searches of MEDLINE (1996 to August 2012), other databases, and reference lists. Randomized, controlled trials (RCTs) and cohort studies of rhBMP-2 versus any control and uncontrolled studies of harms. Effectiveness outcomes in IPD were recalculated using consistent definitions. Study characteristics and results were abstracted by 1 investigator and confirmed by another. Two investigators independently assessed quality using predefined criteria. Thirteen RCTs and 31 cohort studies were included. For lumbar spine fusion, rhBMP-2 and iliac crest bone graft were similar in overall success, fusion, and other effectiveness measures and in risk for any adverse event, although rates were high across interventions (77% to 93% at 24 months from surgery). For anterior lumbar interbody fusion, rhBMP-2 was associated with nonsignificantly increased risk for retrograde ejaculation and urogenital problems. For anterior cervical spine fusion, rhBMP-2 was associated with increased risk for wound complications and dysphagia. At 24 months, the cancer risk was increased with rhBMP-2 (risk ratio, 3.45 [95% CI, 1.98 to 6.00]), but event rates were low and cancer was heterogeneous. Early journal publications misrepresented the effectiveness and harms through selective reporting, duplicate publication, and underreporting. Outcome assessment was not blinded, and ascertainment of harms in trials was poor. No trials were truly independent of industry sponsorship. In spinal fusion, rhBMP-2 has no proven clinical advantage over bone graft and may be associated with important harms, making it difficult to identify clear indications for rhBMP-2. Earlier disclosure of all relevant data would have better informed clinicians and the public than the initial published trial reports did. Yale University and Medtronic.

Surgical infrarenal "neo-neck" technique during elective conversion after EVAR with suprarenal fixation.

PubMed

Bonvini, S; Wassermann, V; Menegolo, M; Scrivere, P; Grego, F; Piazza, M

2015-08-01

Conversion of a previous endovascular aneurysm repair (EVAR) with suprarenal fixation is a challenging situation even in the elective setting. The outcomes of a technique based on preservation of the first proximal covered stent of the endograft, used as a "neo-neck" for proximal anastomosis, are presented. From 2001 to 2014, nine patients underwent elective conversion of a previous suprarenally fixed EVAR. After supraceliac clamping, the aneurysm sac was opened and the endograft identified; the fabric was cut beyond the first covered stent together with its native aortic wall in order to create a "neo-neck." An aortic balloon was inflated into the visceral aorta to avoid back bleeding. A Dacron bifurcated tube graft (Intergard, Maquet) was then sutured to the neo-neck mimicking endobanding, passing the stitches into the aortic wall and the first covered stent. The mean age was 68 years (range, 52-84 years). The stent grafts removed were four Zenith (Cook Medical), three Endurant (Medtronic), and two E-vita (Jotec). The indication for conversion was type 1A (n = 2), type 2 (n = 2), and type 3 (n = 1) endoleak, complete endograft thrombosis (n = 2), and abdominal pain with sac enlargement with no radiological sign of endoleak (n = 2). Blood loss was 1,428 mL (range 500-3,000 mL); the visceral ischemic time to perform the proximal anastomosis was 23.5 min ± 2.3 min). The post-operative complication rate was 11% (n = 1/9) related to a case of sac wall bleeding requiring re-intervention; mortality at 30 days was 0%. At 22 months (range, 8-41) the computed tomography angiogram demonstrated no signs of leaks or anastomotic pseudoaneurysm. Preservation of the proximal covered stent of an endograft with suprarenal fixation used as an infrarenal "neo-neck" with incorporation of the aorta to the suture line during elective surgical explantation simplifies the procedure, and can be achieved with very low early morbidity and mortality; furthermore, it seems to be durable over mid-term follow up. Copyright © 2015 European Society for Vascular Surgery. Published by Elsevier Ltd. All rights reserved.

Hydrodynamic performance and heat generation by centrifugal pumps.

PubMed

Ganushchak, Y; van Marken Lichtenbelt, W; van der Nagel, T; de Jong, D S

2006-11-01

For over a century, centrifugal pumps (CP) have been used in various applications, from large industrial pumps to flow pumps for aquariums. However, the use of CP as blood pumps has a rather short history. Consequently, the hydraulic performance data for a blood CP are limited. The aim of our investigation was to study the hydraulic performance and the heat generation of three commercially available CP: Bio-Medicus Bio-Pump BP80 (Medtronic), Rotaflow (Jostra Medizintechnik), and DeltaStream DP2 (MEDOS Medizintechnik AQ). The study was performed using a circuit primed with a water-glycerin mixture with a dynamic viscosity of 0.00272 pa/s. Pressure-flow curves were obtained by a stepwise stagnation of the pump outlet or inlet. The temperature changes were observed using ThermaCAM SC2000 (Flir Systems). The pumps' performance in close to clinical conditions ('operating region') was analysed in this report. The 'operating region' in the case of the BP80 is positioned around the pressure-flow curve at a pump speed of 3000 rpm. In the case of the Rotaflow, the 'operating region' was between the pump pressure-flow curves at a speed of 3000 and 4000 rpm, and the DP2 was found between 7000 and 8000 rpm. The standard deviation of mean pressure through the pump was used to characterise the stability of the pump. In experiments with outlet stagnation, the BP80 demonstrated high negative association between flow and pressure variability (r = -0.68, p < 0.001). In experiments with the DP2, this association was positive (r = 0.68, p < 0.001). All pumps demonstrated significantly higher variability of pressure in experiments with inlet stagnation in comparison to the experiments with outlet stagnation. The rise of relative temperature in the inlet of a pump was closely related to the flow rate. The heating of fluid was more pronounced in the 'zero-flow' mode, especially in experiments with inlet stagnation. In summary, (1) the 'zero-flow' regime, which is described in the manuals of some commercially-available pumps, is the use of the pump outside the allowable operating region. It is potentially dangerous and should, therefore, never be used in clinical settings. (2) Using centrifugal pumps for kinetic-assisted venous return can only be performed safely when the negative pressure at the inlet of the pump is monitored continuously. The maximum allowable negative pressure has to be defined for each type of pump, and must be based on pump performance.

Threshold-based insulin-pump interruption for reduction of hypoglycemia.

PubMed

Bergenstal, Richard M; Klonoff, David C; Garg, Satish K; Bode, Bruce W; Meredith, Melissa; Slover, Robert H; Ahmann, Andrew J; Welsh, John B; Lee, Scott W; Kaufman, Francine R

2013-07-18

The threshold-suspend feature of sensor-augmented insulin pumps is designed to minimize the risk of hypoglycemia by interrupting insulin delivery at a preset sensor glucose value. We evaluated sensor-augmented insulin-pump therapy with and without the threshold-suspend feature in patients with nocturnal hypoglycemia. We randomly assigned patients with type 1 diabetes and documented nocturnal hypoglycemia to receive sensor-augmented insulin-pump therapy with or without the threshold-suspend feature for 3 months. The primary safety outcome was the change in the glycated hemoglobin level. The primary efficacy outcome was the area under the curve (AUC) for nocturnal hypoglycemic events. Two-hour threshold-suspend events were analyzed with respect to subsequent sensor glucose values. A total of 247 patients were randomly assigned to receive sensor-augmented insulin-pump therapy with the threshold-suspend feature (threshold-suspend group, 121 patients) or standard sensor-augmented insulin-pump therapy (control group, 126 patients). The changes in glycated hemoglobin values were similar in the two groups. The mean AUC for nocturnal hypoglycemic events was 37.5% lower in the threshold-suspend group than in the control group (980 ± 1200 mg per deciliter [54.4 ± 66.6 mmol per liter] × minutes vs. 1568 ± 1995 mg per deciliter [87.0 ± 110.7 mmol per liter] × minutes, P<0.001). Nocturnal hypoglycemic events occurred 31.8% less frequently in the threshold-suspend group than in the control group (1.5 ± 1.0 vs. 2.2 ± 1.3 per patient-week, P<0.001). The percentages of nocturnal sensor glucose values of less than 50 mg per deciliter (2.8 mmol per liter), 50 to less than 60 mg per deciliter (3.3 mmol per liter), and 60 to less than 70 mg per deciliter (3.9 mmol per liter) were significantly reduced in the threshold-suspend group (P<0.001 for each range). After 1438 instances at night in which the pump was stopped for 2 hours, the mean sensor glucose value was 92.6 ± 40.7 mg per deciliter (5.1 ± 2.3 mmol per liter). Four patients (all in the control group) had a severe hypoglycemic event; no patients had diabetic ketoacidosis. This study showed that over a 3-month period the use of sensor-augmented insulin-pump therapy with the threshold-suspend feature reduced nocturnal hypoglycemia, without increasing glycated hemoglobin values. (Funded by Medtronic MiniMed; ASPIRE ClinicalTrials.gov number, NCT01497938.).

Electromagnetic interference from welding and motors on implantable cardioverter-defibrillators as tested in the electrically hostile work site.

PubMed

Fetter, J G; Benditt, D G; Stanton, M S

1996-08-01

This study was designed to determine the susceptibility of an implanted cardioverter-defibrillator to electromagnetic interference in an electrically hostile work site environment, with the ultimate goal of allowing the patient to return to work. Normal operation of an implanted cardioverter-defibrillator depends on reliable sensing of the heart's electrical activity. Consequently, there is concern that external electromagnetic interference from external sources in the work place, especially welding equipment or motor-generator systems, may be sensed and produce inappropriate shocks or abnormal reed switch operation, temporarily suspending detection of ventricular tachycardia or ventricular fibrillation. The effects of electromagnetic interference on the operation of one type of implantable cardioverter-defibrillator (Medtronic models 7217 and 7219) was measured by using internal event counter monitoring in 10 patients operating arc welders at up to 900 A or working near 200-hp motors and 1 patient close to a locomotive starter drawing up to 400 A. The electromagnetic interference produced two sources of potential interference on the sensing circuit or reed switch operation, respectively: 1) electrical fields with measured frequencies up to 50 MHz produced by the high currents during welding electrode activation, and 2) magnetic fields produced by the current in the welding electrode and cable. The defibrillator sensitivity was programmed to the highest (most sensitive) value: 0.15 mV (model 7219) or 0.3 mV (model 7217). The ventricular tachycardia and ventricular fibrillation therapies were temporarily turned off but the detection circuits left on. None of the implanted defibrillators tested were affected by oversensing of the electric field as verified by telemetry from the detection circuits. The magnetic field from 225-A welding current produced a flux density of 1.2 G; this density was not adequate to close the reed switch, which requires approximately 10 G. Our testing at the work site revealed no electrical interference with this type of defibrillator. Patients were allowed to return to work. The following precautions should be observed by the patient: 1) maintain a minimal distance of 2 ft (61 cm) from the welding arc and cables or large motors, 2) do not exceed tested currents with the welding equipment, 3) wear insulated gloves while operating electrical equipment, 4) verify that electrical equipment is properly grounded, and 5) stop welding and leave the work area immediately if a therapy is delivered or a feeling of lightheadedness is experienced.

Clinical performance of three bolus calculators in subjects with type 1 diabetes mellitus: a head-to-head-to-head comparison.

PubMed

Zisser, Howard; Wagner, Robin; Pleus, Stefan; Haug, Cornelia; Jendrike, Nina; Parkin, Chris; Schweitzer, Matthias; Freckmann, Guido

2010-12-01

Insulin pump systems now provide automated bolus calculators (ABCs) that electronically calculate insulin boluses to address carbohydrate intake and out-of-range blood glucose (bG) levels. We compared the efficacy of three ABCs (Accu-Chek(®) Combo [Roche Insulin Delivery Systems (IDS), Inc., Fishers, IN, a member of the Roche Group], Animas(®) 2020 [Animas Corp., West Chester, PA, a Johnson and Johnson company], and MiniMed Paradigm Bolus Wizard(®) [Medtronic MiniMed, Northridge, CA]) to safely reduce postprandial hyperglycemia in type 1 diabetes mellitus (T1DM). T1DM subjects (n = 24) were recruited at a single center for a prospective, triple crossover study. ABCs with the programmed target range (80-140 mg/dL) were used in random order. Postprandial hyperglycemia was induced by reducing the calculated bolus by 25%. Two hours after test meals, the ABCs were allowed to determine whether a correction bolus was needed. Differences between 6-h bG values after test meals that achieved 2-h postprandial hyperglycemia and the mean of the target range (110 mg/dL) were determined. The mean difference between 6-h bG levels following test meals and the 110 mg/dL bG target with the MiniMed device (47.4 ± 31.8 mg/dL) was significantly higher than the Animas (17.3 ± 30.9 mg/dL) and Roche IDS (18.8 ± 33.8 mg/dL) devices (P = 0.0022 and P = 0.0049, respectively). The number of meals with 2-h postprandial hyperglycemia and bG levels at 2 h was similar. Roche IDS and Animas devices recommended correction boluses significantly (P = 0.0001 and P = 0.0002, respectively) more frequently than the MiniMed device. ABC use was not associated with severe hypoglycemia. There was no significant difference in the rate of mild hypoglycemia (bG <60 mg/dL not requiring assistance) among the three groups (Roche IDS and Animas, n = 2; MiniMed, n = 0). In this study, the Roche IDS and Animas devices were more efficacious in controlling postprandial hyperglycemia than the MiniMed device. This may be due, in part, to differences in ABC setup protocols and algorithms. Use of ABCs can assist in controlling postprandial glycemia without significant hypoglycemia.

Fractional flow reserve versus angiography for guidance of PCI in patients with multivessel coronary artery disease (FAME): 5-year follow-up of a randomised controlled trial.

PubMed

van Nunen, Lokien X; Zimmermann, Frederik M; Tonino, Pim A L; Barbato, Emanuele; Baumbach, Andreas; Engstrøm, Thomas; Klauss, Volker; MacCarthy, Philip A; Manoharan, Ganesh; Oldroyd, Keith G; Ver Lee, Peter N; Van't Veer, Marcel; Fearon, William F; De Bruyne, Bernard; Pijls, Nico H J

2015-11-07

In the Fractional Flow Reserve Versus Angiography for Multivessel Evaluation (FAME) study, fractional flow reserve (FFR)-guided percutaneous coronary intervention (PCI) improved outcome compared with angiography-guided PCI for up to 2 years of follow-up. The aim in this study was to investigate whether the favourable clinical outcome with the FFR-guided PCI in the FAME study persisted over a 5-year follow-up. The FAME study was a multicentre trial done in Belgium, Denmark, Germany, the Netherlands, Sweden, the UK, and the USA. Patients (aged ≥ 18 years) with multivessel coronary artery disease were randomly assigned to undergo angiography-guided PCI or FFR-guided PCI. Before randomisation, stenoses requiring PCI were identified on the angiogram. Patients allocated to angiography-guided PCI had revascularisation of all identified stenoses. Patients allocated to FFR-guided PCI had FFR measurements of all stenotic arteries and PCI was done only if FFR was 0·80 or less. No one was masked to treatment assignment. The primary endpoint was major adverse cardiac events at 1 year, and the data for the 5-year follow-up are reported here. Analysis was by intention to treat. This trial is registered with ClinicalTrials.gov, number NCT00267774. After 5 years, major adverse cardiac events occurred in 31% of patients (154 of 496) in the angiography-guided group versus 28% (143 of 509 patients) in the FFR-guided group (relative risk 0·91, 95% CI 0·75-1·10; p=0·31). The number of stents placed per patient was significantly higher in the angiography-guided group than in the FFR-guided group (mean 2·7 [SD 1·2] vs 1·9 [1·3], p<0·0001). The results confirm the long-term safety of FFR-guided PCI in patients with multivessel disease. A strategy of FFR-guided PCI resulted in a significant decrease of major adverse cardiac events for up to 2 years after the index procedure. From 2 years to 5 years, the risks for both groups developed similarly. This clinical outcome in the FFR-guided group was achieved with a lower number of stented arteries and less resource use. These results indicate that FFR guidance of multivessel PCI should be the standard of care in most patients. St Jude Medical, Friends of the Heart Foundation, and Medtronic. Copyright © 2015 Elsevier Ltd. All rights reserved.

Is platelet function as measured by Thrombelastograph monitoring in whole blood affected by platelet inhibitors?

PubMed

Bailey, Lori A; Sistino, Joseph J; Uber, Walter E

2005-03-01

Platelet inhibitors, especially the glycoprotein (GP) IIb/IIIa receptor antagonists, have demonstrated their effectiveness in reducing the acute ischemic complications of percutaneous coronary intervention (PCI) and in improving clinical outcomes in patients with acute coronary crisis. Three common platelet inhibitors observed in emergent cardiopulmonary bypass (CPB) for failed PCI are abciximab, eptifibatide, and tirofiban. An in vitro model was constructed in two parts to determine whether platelet aggregation inhibition induced by platelet inhibitors would be demonstrated by the Thrombelastograph (TEG) monitor when compared with baseline samples with no platelet inhibitor. In part A, 20 mL of fresh whole blood was divided into four groups: group I = baseline, group A = abcix-imab microg/mL, group E = eptifibatide ng/mL, and group T = tirofiban ng/mL. Platelet inhibitor concentrations in whole blood were derived starting with reported serum concentrations with escalation to achieve 80% platelet inhibition using the Medtronic hemoSTATUS and/or Lumi-aggregometer. A concentration range determined by our in vitro tests were chosen for each drug using concentrations achieving less than, equal to, or greater than 80% platelet inhibition. In part B, TEG analysis was then performed using baseline and concentrations for each drug derived in part A. Parameters measured were clot formation reaction time (R), coagulation time (K), maximum amplitude (MA) and alpha angle (A). Groups E1000 and E2000 extended R over control by 37% and 23%, respectively (p = 0.01 and 0.03). Groups E1000 and E2000 increased K times by 45% and 58% (p = .02 and .04). T160 samples prolonged K by 20% (p = 0.01). The angle or clot strength (A) was decreased in groups T160 and E1000 by 23% (+ 7.06 SD) and 18% (+ 11.23 SD), respectively (p = 0.001 and 0.01). The MA decrease was statistically significant in the T160, E1000 and E2000 by 9%, 6% and 13% respectively (p = 0.01). Samples treated with abciximab were comparable to control values for all parameters measured. Although statistical significance could be demonstrated with some parameters, sensitivity was only observed at increased doses and was not seen with all agents tested. In our in vitro model, the TEG monitor was unable to demonstrate clinically significant differences in platelet function and may not be reflective of platelet function in samples which have been treated with these GP IIb/IIIa inhibitors.

Future of robotic surgery in urology.

PubMed

Rassweiler, Jens J; Autorino, Riccardo; Klein, Jan; Mottrie, Alex; Goezen, Ali Serdar; Stolzenburg, Jens-Uwe; Rha, Koon H; Schurr, Marc; Kaouk, Jihad; Patel, Vipul; Dasgupta, Prokar; Liatsikos, Evangelos

2017-12-01

To provide a comprehensive overview of the current status of the field of robotic systems for urological surgery and discuss future perspectives. A non-systematic literature review was performed using PubMed/Medline search electronic engines. Existing patents for robotic devices were researched using the Google search engine. Findings were also critically analysed taking into account the personal experience of the authors. The relevant patents for the first generation of the da Vinci platform will expire in 2019. New robotic systems are coming onto the stage. These can be classified according to type of console, arrangement of robotic arms, handles and instruments, and other specific features (haptic feedback, eye-tracking). The Telelap ALF-X robot uses an open console with eye-tracking, laparoscopy-like handles with haptic feedback, and arms mounted on separate carts; first clinical trials with this system were reported in 2016. The Medtronic robot provides an open console using three-dimensional high-definition video technology and three arms. The Avatera robot features a closed console with microscope-like oculars, four arms arranged on one cart, and 5-mm instruments with six degrees of freedom. The REVO-I consists of an open console and a four-arm arrangement on one cart; the first experiments with this system were published in 2016. Medicaroid uses a semi-open console and three robot arms attached to the operating table. Clinical trials of the SP 1098-platform using the da Vinci Xi for console-based single-port surgery were reported in 2015. The SPORT robot has been tested in animal experiments for single-port surgery. The SurgiBot represents a bedside solution for single-port surgery providing flexible tube-guided instruments. The Avicenna Roboflex has been developed for robotic flexible ureteroscopy, with promising early clinical results. Several console-based robots for laparoscopic multi- and single-port surgery are expected to come to market within the next 5 years. Future developments in the field of robotic surgery are likely to focus on the specific features of robotic arms, instruments, console, and video technology. The high technical standards of four da Vinci generations have set a high bar for upcoming devices. Ultimately, the implementation of these upcoming systems will depend on their clinical applicability and costs. How these technical developments will facilitate surgery and whether their use will translate into better outcomes for our patients remains to be determined. © 2017 The Authors BJU International © 2017 BJU International Published by John Wiley & Sons Ltd.

Feasibility of dual-chamber (DDD) pacing via a single-pass (VDD) pacing lead employing a floating atrial ring (dipole): case series, future considerations, and refinements.

PubMed

Kassotis, John; Voigt, Louis; Mongwa, Mbu; Reddy, C V R

2005-01-01

The objective of this study was to assess the feasibility of DDD pacing from a standard single-pass VDD pacemaker system. Over the past 2 decades significant advances have been made in the development of single-pass VDD pacing systems. These have been shown in long-term prospective studies to effectively preserve atrioventricular (AV)synchrony in patients with AV block and normal sinus node function. What remains problematic is the development of a single-pass pacing system capable of DDD pacing. Such a lead configuration would be useful in those patients with peripheral venous anomalies and in younger patients with congenital anomalies, which may require lead revisions in the future. In addition, with the increased use of resynchronization (biventricular pacing) therapy, the availability of a reliable single-pass lead will minimize operative time, enhance patient safety, and minimize the amount of hardware within the heart. The feasibility of DDD pacing via a Medtronic Capsure VDD-2 (Model #5038) pacing lead was evaluated. Twenty patients who presented with AV block and normal sinus node function were recruited for this study. Atrial pacing thresholds and sensitivities were assessed intraoperatively in the supine position with various respiratory maneuvers. Five patients who agreed to participate in long-term follow-up received a dual-chamber generator and were evaluated periodically over a 12-month period. Mean atrial sensitivity was 2.35 +/- 0.83 mV at the time of implantation. Effective atrial stimulation was possible in all patients at the time of implantation (mean stimulation threshold 3.08 +/- 1.04 V at 0.5 ms [bipolar], 3.34 +/- 0.95 V at 0.5 ms [unipolar]). Five of the 20 patients received a Kappa KDR701 generator, and atrial electrical properties were followed up over a 1-year period. There was no significant change in atrial pacing threshold or incidence of phrenic nerve stimulation over the 1-year follow-up. A standard single-pass VDD pacing lead system was capable of DDD pacing intraoperatively and during long-term follow-up. Despite higher than usual thresholds via the atrial dipole, pacemaker telemetry revealed < 10% use of atrial pacing dipole over a 12-month period, which would minimally deplete the pacemaker's battery. In addition, the telemetry confirmed appropriate sensing and pacing of the atrial dipole throughout the study period. At this time such systems can serve as back-up DDD pacing systems with further refinements required to optimize atrial thresholds in all patients.

Embolic protection for renal artery stenting.

PubMed

Henry, M; Henry, I; Polydorou, A; Hugel, M

2008-10-01

A renal artery stenosis (RAS) is frequent and usually caused by atherosclerosis. Percutaneous renal artery angioplasty (PTRA) and stenting gives good immediate and long-term Concern has arisen in the postprocedural deterioration of the renal function (RF), which may occur in 20-40% of the patients therefore limiting the immediate benefits of the technique. Atheroembolism seems to play an important role in postprocedural deterioration. The authors postulated that the use of renal embolic protection devices could reduce the risk of renal embolism and avoid deterioration of the RF. One hundred forty-eight PTRA and stenting procedures were performed under protection in 121 hypertensive patients (M: 85), mean age: 64.5+/-11.8 years (22-87) with atherosclerotic renal artery stenosis. Eleven patients had solitary kidneys and 48 had renal insufficiency. Both occlusion balloons (N=46) and filters (N=95) were used. Of the 95 filters, the new FiberNet EP system (Lumen Biomedical) was included. This filter has the ability to capture particles as small as 30-40 microns without compromising flow. Generated debris was then removed and analysed, and blood pressure and serum creatinine levels were followed. Immediate technical success: was achieved in 100% os the cases. 112/141 lesions were stented directly. Visible debris with Percusurge (Medtronic) was aspirated and removed under aspiration from all patients and in 80% of the cases with filters. Debris was aspirated in 100% of the cases completed with the FiberNet). The mean particulate retrieved with the Percusurge system was 98.1+/-60.0 mu with a mean diameter ranging from 201+/-76 m (38-6 206). Mean occlusion time was 6.55+/-2.46 min and mean time in situ (filters) 4.2+/-1.1 min. Five times more particulate was removed with the FiberNet than with current available filters. One acute RF deterioration was observed. The mean follow-up was 29.6+/-14 months and the mean creatinine level remained constant during follow-up. At 6 months (101 patients) one deterioration of the RF in a patient with renal insufficiency at baseline was observed, 25 improvements in patients with renal insufficiency were noted, and 73 stabilizations. In conclusion 99% of the patients were stabilized or improved. After 2 years (84 patients) 95% of the patients remained stabilized (N=60) or showed improvements (N=20), and 4 patients had deterioration of RF (5%). The preliminary results suggest the feasibility and safety of distal protection during renal interventions to protect against atheroembolism and consequential deterioration of RF after the procedure. The beneficial effects of this technique should be evaluated further in randomized studies.

WE-EF-BRA-03: Catheter- Free Ablation with External Photon Radiation: Treatment Planning, Delivery Considerations, and Correlation of Effects with Delivered Dose

DOE Office of Scientific and Technical Information (OSTI.GOV)

Deisher, A; Anderson, S; Cusma, J

Purpose: To plan, target, and calculate delivered dose in atrioventricular node (AVN) ablation with volume-modulated arc therapy (VMAT) in an intact porcine model. Methods: Seven pigs underwent AVN irradiation, with prescription doses ranging between 25 and 55Gy in a single fraction. Cardiac CT scans were acquired at expiration. Two physicians contoured AVN targets on 10 phases, providing estimates of target motion and inter-physician variability. Treatment planning was conducted on a static phase-averaged CT. The volume designated to receive prescription dose covered the full extent of AVN cardiac motion, expanded by 4mm for setup uncertainty. Optimization limited doses to risk structuresmore » according to single-fraction tumor treatment protocols. Orthogonal kV images were used to align bony anatomy at time of treatment. Localization was further refined with respiratory-gated cone-beam CT, and range of cardiac motion was verified under fluoroscopy. Beam delivery was respiratory-gated for expiration with a mean efficiency of 60%. Deformable registration of the 10 cardiac CT phases was used to calculate actual delivered dose for comparison to electro-anatomical and visually evident lesions. Results: The mean [minimum,maximum] amplitude of AVN cardiac motion was LR 2.9 [1.7,3.9]mm, AP 6.6 [4.4,10.4]mm, and SI 5.6 [2.0,9.9]mm. Incorporating cardiac motion into the dose calculation showed the volume receiving full dose was 40–80% of the volume indicated on the static planning image, although the contoured AVN target received full dose in all animals. Initial results suggest the dimensions of the electro-anatomical lesion are correlated with the 40Gy isodose volume. Conclusion: Image-guidance techniques allow for accurate and precise delivery of VMAT for catheter-free arrhythmia ablation. An arsenal of advanced radiation planning, dose optimization, and image-guided delivery techniques was employed to assess and mitigate effects of cardiac and respiratory motion. Feasibility of delivery to the pulmonary veins and left ventricular myocardium will be investigated in future studies. D. Packer Disclosures: Abiomed, Biosense Webster, Inc., Boston Scientific Corp., CardioFocus, Inc., Johnson and Johnson, Excerpta Medica, Ortho-McNeil-Jannsen, Sanofi Aventis, CardioInsight Technologies, InfoBionic, SIEMENS, Medtronic, Inc., CardioDx, Inc., CardioInsight Technologies, FoxP2 Medica, Mediasphere Medical, Wiley-Blackwell, St. Jude Medical, Endosense, Thermedical, EP Advocate LLC, Hansen Medical, American Heart Association, EpiEP, NIH.« less

Qualitative Evaluation of Fiducial Markers for Radiotherapy Imaging

PubMed Central

Chan, Maria F.; Cohen, Gil’ad N.; Deasy, Joseph O.

2016-01-01

Purpose To evaluate visibility, artifacts, and distortions of various commercial markers in magnetic resonance imaging (MRI), computer tomography (CT), and ultrasound imaging used for radiotherapy planning and treatment guidance. Methods We compare 2 solid gold markers, 4 gold coils, and 1 polymer marker from 3 vendors. Imaging modalities used were 3-T and 1.5-T GE MRIs, Siemens Sequoia 512 Ultrasound, Phillips Big Bore CT, Varian Trilogy linear accelerator (cone-beam CT [CBCT], on-board imager kilovoltage [OBI-kV], electronic portal imaging device megavoltage [EPID-MV]), and Medtronic O-ARM CBCT. Markers were imaged in a 30 × 30 × 10 cm3 custom bolus phantom. In one experiment, Surgilube was used around the markers to reduce air gaps. Images were saved in Digital Imaging and Communications in Medicine (DICOM) format and analyzed using an in-house software. Profiles across the markers were used for objective comparison of the markers’ signals. The visibility and artifacts/distortions produced by each marker were assessed qualitatively and quantitatively. Results All markers are visible in CT, CBCT, OBI-kV, and ultrasound. Gold markers below 0.75 mm in diameter are not visible in EPID-MV images. The larger the markers, the more CT and CBCT image artifacts there are, yet the degree of the artifact depends on scan parameters and the scanner itself. Visibility of gold coils of 0.75 mm diameter or larger is comparable across all imaging modalities studied. The polymer marker causes minimal artifacts in CT and CBCT but has poor visibility in EPID-MV. Gold coils of 0.5 mm exhibit poor visibility in MRI and EPID-MV due to their small size. Gold markers are more visible in 3-T T1 gradient-recalled echo than in 1.5-T T1 fast spin-echo, depending on the scan sequence. In this study, all markers are clearly visible on ultrasound. Conclusion All gold markers are visible in CT, CBCT, kV, and ultrasound; however, only the large diameter markers are visible in MV. When MR and EPID-MV imagers are used, the selection of fiducial markers is not straightforward. For hybrid kV/MV image-guided radiotherapy imaging, larger diameter markers are suggested. If using kV imaging alone, smaller sized markers may be used in smaller sized patients in order to reduce artifacts. Only larger diameter gold markers are visible across all imaging modalities. PMID:25230715

Pallidal deep brain stimulation in patients with primary generalised or segmental dystonia: 5-year follow-up of a randomised trial.

PubMed

Volkmann, Jens; Wolters, Alexander; Kupsch, Andreas; Müller, Jörg; Kühn, Andrea A; Schneider, Gerd-Helge; Poewe, Werner; Hering, Sascha; Eisner, Wilhelm; Müller, Jan-Uwe; Deuschl, Günther; Pinsker, Marcus O; Skogseid, Inger-Marie; Roeste, Geir Ketil; Krause, Martin; Tronnier, Volker; Schnitzler, Alfons; Voges, Jürgen; Nikkhah, Guido; Vesper, Jan; Classen, Joseph; Naumann, Markus; Benecke, Reiner

2012-12-01

Severe forms of primary dystonia are difficult to manage medically. We assessed the safety and efficacy of pallidal neurostimulation in patients with primary generalised or segmental dystonia prospectively followed up for 5 years in a controlled multicentre trial. In the parent trial, 40 patients were randomly assigned to either sham neurostimulation or neurostimulation of the internal globus pallidus for a period of 3 months and thereafter all patients completed 6 months of active neurostimulation. 38 patients agreed to be followed up annually after the activation of neurostimulation, including assessments of dystonia severity, pain, disability, and quality of life. The primary endpoint of the 5-year follow-up study extension was the change in dystonia severity at 3 years and 5 years as assessed by open-label ratings of the Burke-Fahn-Marsden dystonia rating scale (BFMDRS) motor score compared with the preoperative baseline and the 6-month visit. The primary endpoint was analysed on an intention-to-treat basis. The original trial is registered with ClinicalTrials.gov (NCT00142259). An intention-to-treat analysis including all patients from the parent trial showed significant improvements in dystonia severity at 3 years and 5 years compared with baseline, which corresponded to -20·8 points (SD 17·1; -47·9%; n=40) at 6 months; -26·5 points (19·7; -61·1%; n=31) at 3 years; and -25·1 points (21·3; -57·8%; n=32). The improvement from 6 months to 3 years (-5·7 points [SD 8·4]; -34%) was significant and sustained at the 5-year follow-up (-4·3 [10·4]). 49 new adverse events occurred between 6 months and 5 years. Dysarthria and transient worsening of dystonia were the most common non-serious adverse events. 21 adverse events were rated serious and were almost exclusively device related. One patient attempted suicide shortly after the 6-month visit during a depressive episode. All serious adverse events resolved without permanent sequelae. 3 years and 5 years after surgery, pallidal neurostimulation continues to be an effective and relatively safe treatment option for patients with severe idiopathic dystonia. This long-term observation provides further evidence in favour of pallidal neurostimulation as a first-line treatment for patients with medically intractable, segmental, or generalised dystonia. Medtronic. Copyright © 2012 Elsevier Ltd. All rights reserved.

Risk Factors for Permanent Pacemaker after Implantation of Surgical or Percutaneous Self-Expanding Aortic Prostheses.

PubMed

Villa, Emmanuel; Clerici, Alberto; Messina, Antonio; Testa, Luca; Bedogni, Francesco; Moneta, Andrea; Donatelli, Francesco; Troise, Giovanni

2016-11-01

The use of transcatheter aortic valve implantation (TAVI) following the introduction of Nitinol autoexpandable devices has spread rapidly during recent years. In addition, cardiac surgery has been revolutionized due to the use of Nitinol-based sutureless prostheses for aortic valve replacement (AVR). During the same period, however, permanent pacemaker (PPM) implantation has emerged as a frequent complication. The study aim was to identify the risk factors of PPM following the implantation of a Nitinol self-expanding prosthesis (for AVR or TAVI). A study group was created between two institutions experienced in the use of nitinol devices, and a pool of 336 patients (56.6% CoreValve - Medtronic; 43.4% Perceval - Sorin) was available for a retrospective analysis. Pre-procedural clinical and electrocardiography (ECG) variables and postprocedural ECG variables were compared between the PPM group and control patients who had not received a PPM during their index hospitalization. A PPM was required in 12.8% of patients (TAVI 17.5% versus AVR 6.8%, p = 0.007). PPM patients had a higher logistical EuroSCORE (median 20.77% versus 15.59%, p = 0.015), a lower use of statins (18.6% versus 34.2%, p = 0.04), a pre-procedural longer QRS interval (median 117 ms versus 98 ms, p = 0.002), and a higher incidence of conduction disturbances (29.3% versus 16.8%, p = 0.034), with a prevalence of right bundle branch block. At the first postprocedural ECG, non-stimulated PPM patients had a longer QRS interval (median 150 ms versus 113 ms, p<0.001) and a longer QTc interval (487.3 ± 46 ms versus 510.8 ± 53.8 ms, p = 0.005). Prevalent intra-ventricular conduction disorders in both groups included left bundle branch block. AVR patients received a PPM later than the TAVI group (median 6 days versus 3 days, p = 0.01). TAVI was an independent predictor of PPM at logistic regression analysis (OR 3.18; 95% CI 1.19-8.48, p = 0.021), but the significance disappeared after incorporating post-procedural ECG variables. Nitinol technology is a ground-breaking option for aortic valve procedures. However, the radial forces of the self-expandable mechanism may be implicated in the increased need for PPM, mostly in cases of TAVI compared to AVR, that most likely are due to displacement of the stent provoked by in situ calcium clusters. Given the clinical and economic impact of PPM, new parameters are required to understand the stent/tissue interaction and to help with device selection.

Hemodynamic changes during displacement of the beating heart using epicardial stabilization for off-pump coronary artery bypass graft surgery.

PubMed

Mishra, Manisha; Malhotra, Rajneesh; Mishra, Anil; Meharwal, Zile Singh; Trehan, Naresh

2002-12-01

To evaluate the hemodynamic alterations during off-pump coronary artery bypass graft surgery to determine the degree of impairment caused and the techniques to rectify them. Prospective, observational cohort study performed from January 2000 through September 2000. Patients (n = 500) with coronary artery disease undergoing multivessel off-pump coronary artery bypass graft surgery using the Octopus tissue stabilizer (Medtronic, Inc, Minneapolis, MN). Unstable patients with ongoing ischemia were excluded from the study. All patients were monitored with radial artery and pulmonary artery catheters and continuous transesophageal echocardiography monitoring with a multiplane transducer. The perioperative requirement of an intracoronary shunt, inotropes, or an intra-aortic balloon pump was noted. The effect of the Trendelenburg position and fluids on hemodynamics was observed. The need for defibrillation and institution of emergency cardiopulmonary bypass were major endpoints to determine the inability of the patient to tolerate displacement of the heart. Mean patient age was 59.3 +/- 11.6 years. There were 204 (40%) patients in the high-risk category; 54 (10.8%) patients had left ventricular ejection fraction <25%. The mean number of grafts was 2.7 +/- 0.8. Vertical displacement of the heart to access the lateral and inferior walls decreased the mean arterial pressure by 18 +/- 4% (p < 0.01), with a concomitant increase in central venous pressure of 66 +/- 18% (p < 0.001). The stroke volume and the cardiac index were reduced by 35.7 +/- 11% (p < 0.001) and 45 +/- 13% (p < 0.001). On transesophageal echocardiography, there was development of new regional wall motion abnormalities in 59.2% and a decrease in global left ventricular functions in 61.2%. The use of inotropes was highest during anastomosis on the posterior wall-78.4% compared with 21.9% for the anterior wall. An intra-aortic balloon pump was used in 55 (11.2%) patients, and 7 (0.71 %) patients had to be put on emergency CPB. The in-hospital mortality was 1.2%. Most patients had hemodynamic changes easily correctable by fluids and inotropes. Monitoring of left ventricular and right ventricular function by transesophageal echocardiography enhances safety of the procedure and is recommended. The use of the Octopus II tissue stabilizer proved to be a safe and versatile means to stabilize the heart during off-pump coronary artery bypass procedures, especially in high-risk patients. Copyright 2002, Elsevier Science (USA). All rights reserved.

Improved accuracy of component alignment with the implementation of image-free navigation in total knee arthroplasty.

PubMed

Rosenberger, Ralf E; Hoser, Christian; Quirbach, Sebastian; Attal, Rene; Hennerbichler, Alfred; Fink, Christian

2008-03-01

Accuracy of implant positioning and reconstruction of the mechanical leg axis are major requirements for achieving good long-term results in total knee arthroplasty (TKA). The purpose of the present study was to determine whether image-free computer navigation technology has the potential to improve the accuracy of component alignment in TKA cohorts of experienced surgeons immediately and constantly. One hundred patients with primary arthritis of the knee underwent the unilateral total knee arthroplasty. The cohort of 50 TKAs implanted with conventional instrumentation was directly followed by the cohort of the very first 50 computer-assisted TKAs. All surgeries were performed by two senior surgeons. All patients received the Zimmer NexGen total knee prosthesis (Zimmer Inc., Warsaw, IN, USA). There was no variability regarding surgeons or surgical technique, except for the use of the navigation system (StealthStation) Treon plus Medtronic Inc., Minnesota, MI, USA). Accuracy of implant positioning was measured on postoperative long-leg standing radiographs and standard lateral X-rays with regard to the valgus angle and the coronal and sagittal component angles. In addition, preoperative deformities of the mechanical leg axis, tourniquet time, age, and gender were correlated. Statistical analyses were performed using the SPSS 15.0 (SPSS Inc., Chicago, IL, USA) software package. Independent t-tests were used, with significance set at P < 0.05 (two-tailed) to compare differences in mean angular values and frontal mechanical alignment between the two cohorts. To compute the rate of optimally implanted prostheses between the two groups we used the chi(2) test. The average postoperative radiological frontal mechanical alignment was 1.88 degrees of varus (range 6.1 degrees of valgus-10.1 degrees of varus; SD 3.68 degrees ) in the conventional cohort and 0.28 degrees of varus (range 3.7 degrees -6.0 degrees of varus; SD 1.97 degrees ) in the navigated cohort. Including all criteria for optimal implant alignment, 16 cases (32%) in the conventional cohort and 31 cases (62%) in the navigated cohort have been implanted optimally. The average difference in tourniquet time was modest with additional 12.9 min in the navigated cohort compared to the conventional cohort. Our findings suggest that the experienced knee surgeons can improve immediately and constantly the accuracy of component orientation using an image-free computer-assisted navigation system in TKA. The computer-assisted technology has shown to be easy to use, safe, and efficient in routine knee replacement surgery. We believe that navigation is a key technology for various current and future surgical alignment topics and minimal-invasive lower limb surgery.

Internal defibrillation: where we have been and where we should be going?

PubMed

Lévy, Samuel

2005-08-01

Internal cardioversion has been developed as an alternative technique for patients who are resistant to external DC cardioversion of atrial fibrillation (AF) and was found to be associated with higher success rates. It used initially high energies (200-300 J) delivered between an intracardiac catheter and a backplate. Subsequent studies have shown that it is possible to terminate with energies of 1 to 6 Joules, paroxysmal or induced AF in 90 percent of patients and persistent AF in 75 percent of patients, using biphasic shocks delivered between a right atrium-coronary sinus vectors. Consequently, internal atrial defibrillation can be performed under sedation only without the need for general anesthesia. Recently developed external defibrillators, capable of delivering biphasic shocks, have increased the success rates of external cardioversion and reduced the need for internal cardioversion. However, internal defibrillation is still useful in overweight or obese patients, in patients with chronic obstructive pulmonary disease or asthma who are more difficult to defibrillate, and in patients with implanted devices which may be injured by high energy shocks. Low energy internal defibrillation has also proven to be safe and this has prompted the development of implantable devices for terminating AF. The first device used was the Metrix system, a stand-alone atrial defibrillator (without ventricular defibrillation) which was found to be safe and effective in selected groups of patients. Unfortunately, this device is no longer being marketed. Only double chamber defibrillators with pacing capabilities are presently available: the Medtronic GEM III AT, an updated version of the Jewel AF and the Guidant PRIZM AVT. These devices can be patient-activated or programmed to deliver automatically ounce atrial tachyarrhythmias are detected, therapies including pacing or/and shocks. Attempts to define the group of patients who might benefit from these devices are described but the respective role of atrial defibrillators versus other non-pharmacologic therapies for AF, such as surgery and radiofrequency catheter ablation, remains to be determined. Advantages and limitations or atrial defibrillators and approaches to reduce shock related discomfort which may be a concern in some patients, are reviewed. Studies have shown that despite shock discomfort, quality of life was improved in patients with atrial defibrillators and the need for repeated hospitalizations was reduced. The cost of these devices remains a concern for the treatment of a non-lethal arrhythmia. Attention that atrial defibrillators will receive from cardiologists and from the industry in the future, will depend of the long-term results of other non-pharmacological options and of the identification of the group of AF patients which will require restoration and maintenance of sinus rhythm. But there is no doubt that selected subsets of patients with AF could benefit from atrial defibrillation.

Percutaneous cardiopulmonary support for catheter ablation of unstable ventricular arrhythmias in high-risk patients.

PubMed

Carbucicchio, Corrado; Della Bella, Paolo; Fassini, Gaetano; Trevisi, Nicola; Riva, Stefania; Giraldi, Francesco; Baratto, Francesca; Marenzi, Giancarlo; Sisillo, Erminio; Bartorelli, Antonio; Alamanni, Francesco

2009-11-01

In patients with severe cardiomyopathy, recurrent episodes of nontolerated ventricular tachycardia (VT) or electrical storm (ES) frequently cause acute heart failure and cardiac death; the suppression of the arrhythmia is therefore lifesaving, but feasibility of catheter ablation (CA) is precluded by the adverse hemodynamic conditions together with the characteristics of the arrhythmia that interdicts efficacious mapping. The use of the percutaneous cardiopulmonary support (CPS) for circulatory assistance may allow patient's stabilization and enhance efficacy and safety of CA in this emergency setting. 19 patients (19 males; mean age 61 +/- 6 years; chronic ischemic cardiomyopathy, eleven patients; primary dilated cardiomyopathy, six patients; arrhythmogenic right ventricular dysplasia/ cardiomyopathy, two patients) with recurrent nontolerated VT episodes undergoing CPS-assisted CA were retrospectively evaluated. Twelve patients had acute hemodynamic failure refractory to inotropic agents and ventilatory assistance, seven patients had undergone a failing nonconventional CA procedure. 14 patients presented with ES, and in twelve the procedure was undertaken under emergency conditions within 24 h from admission. Patients were ventilated under general anesthesia and assisted by a multidisciplinary team. The CPS system consisted in a Medtronic Bio-Medicus centrifugal pump and in a Maxima Plus oxygenator, a 15-F arterial cannula, and a 17-F venous cannula. Flows between 2 and 3 l/min were activated after induction of 56/62 forms of nontolerated VT, achieving hemodynamic stabilization in all patients. CA was mainly guided by conventional activation mapping and was effective in abolishing 45/56 supported VTs; in 10/19 patients all clinical VTs were suppressed by CA. Mean procedural time was 4 h and 20 min. Complete stabilization was achieved in 13 patients (68%) without VT recurrence during a 7-day in-hospital monitoring. A significant clinical improvement was observed in two patients (11%); one patient (5%) with persistent VT episodes acutely died after heart transplant. At a mean follow-up of 42 months (range 15-60 months), 5/18 patients (28%) were free from VT recurrence, 7/18 (39%) had a clear clinical improvement with reduced implantable cardioverter defibrillator interventions. 5/14 patients (36%) had ES recurrence; among them, three died because of acute heart failure. No serious CPS-related complications were observed. The CPS warrants acceptable hemodynamic stabilization and efficacious mapping in high-risk patients undergoing CA for unstable VT in the emergency setting. Safety and efficacy of this technique translate into significant clinical improvement in the majority of patients. Even if only relatively invasive, CPS should be reserved to patients with ES or intractable arrhythmia causing acute heart failure; moreover, the need for an experienced team of multidisciplinary operators implies that its use is restricted to selected high-competency institutions.

Intraoperative changes in transcranial motor evoked potentials and somatosensory evoked potentials predicting outcome in children with intramedullary spinal cord tumors.

PubMed

Cheng, Jason S; Ivan, Michael E; Stapleton, Christopher J; Quinones-Hinojosa, Alfredo; Gupta, Nalin; Auguste, Kurtis I

2014-06-01

Intraoperative dorsal column mapping, transcranial motor evoked potentials (TcMEPs), and somatosensory evoked potentials (SSEPs) have been used in adults to assist with the resection of intramedullary spinal cord tumors (IMSCTs) and to predict postoperative motor deficits. The authors sought to determine whether changes in MEP and SSEP waveforms would similarly predict postoperative motor deficits in children. The authors reviewed charts and intraoperative records for children who had undergone resection for IMSCTs as well as dorsal column mapping and TcMEP and SSEP monitoring. Motor evoked potential data were supplemented with electromyography data obtained using a Kartush microstimulator (Medtronic Inc.). Motor strength was graded using the Medical Research Council (MRC) scale during the preoperative, immediate postoperative, and follow-up periods. Reductions in SSEPs were documented after mechanical traction, in response to maneuvers with the cavitational ultrasonic surgical aspirator (CUSA), or both. Data from 12 patients were analyzed. Three lesions were encountered in the cervical and 7 in the thoracic spinal cord. Two patients had lesions of the cervicomedullary junction and upper spinal cord. Intraoperative MEP changes were noted in half of the patients. In these cases, normal polyphasic signals converted to biphasic signals, and these changes correlated with a loss of 1-2 grades in motor strength. One patient lost MEP signals completely and recovered strength to MRC Grade 4/5. The 2 patients with high cervical lesions showed neither intraoperative MEP changes nor motor deficits postoperatively. Dorsal columns were mapped in 7 patients, and the midline was determined accurately in all 7. Somatosensory evoked potentials were decreased in 7 patients. Two patients each had 2 SSEP decreases in response to traction intraoperatively but had no new sensory findings postoperatively. Another 2 patients had 3 traction-related SSEP decreases intraoperatively, and both had new postoperative sensory deficits that resolved. One additional patient had a CUSA-related SSEP decrease intraoperatively, which resolved postoperatively, and the last patient had 3 traction-related sensory deficits and a CUSA-related sensory deficit postoperatively, none of which resolved. Intraoperative TcMEPs and SSEPs can predict the degree of postoperative motor deficit in pediatric patients undergoing IMSCT resection. This technique, combined with dorsal column mapping, is particularly useful in resecting lesions of the upper cervical cord, which are generally considered to be high risk in this population. Furthermore, the spinal cord appears to be less tolerant of repeated intraoperative SSEP decreases, with 3 successive insults most likely to yield postoperative sensory deficits. Changes in TcMEPs and SSEP waveforms can signal the need to guard against excessive manipulation thereby increasing the safety of tumor resection.

Matched cohort comparison of endovascular abdominal aortic aneurysm repair with and without EndoAnchors.

PubMed

Muhs, Bart E; Jordan, William; Ouriel, Kenneth; Rajaee, Sareh; de Vries, Jean-Paul

2018-06-01

The objective of this study was to examine whether prophylactic use of EndoAnchors (Medtronic, Santa Rosa, Calif) contributes to improved outcomes after endovascular aneurysm repair (EVAR) of abdominal aortic aneurysms through 2 years. The Aneurysm Treatment Using the Heli-FX Aortic Securement System Global Registry (ANCHOR) subjects who received prophylactic EndoAnchors during EVAR were considered for this analysis. Imaging data of retrospective subjects who underwent EVAR at ANCHOR enrolling institutions were obtained to create a control sample. Nineteen baseline anatomic measurements were used to perform propensity score matching, yielding 99 matched pairs. Follow-up imaging of the ANCHOR and control cohorts was then compared to examine outcomes through 2 years, using Kaplan-Meier survival analysis. Freedom from type Ia endoleak was 97.0% ± 2.1% in the ANCHOR cohort and 94.1% ± 2.5% in the control cohort through 2 years (P = .34). The 2-year freedom from neck dilation in the ANCHOR and control cohorts was 90.4% ± 5.6% and 87.3% ± 4.3%, respectively (P = .46); 2-year freedom from sac enlargement was 97.0% ± 2.1% and 94.0% ± 3.0%, respectively (P = .67). No device migration was observed. Aneurysm sac regression was observed in 81.1% ± 9.5% of ANCHOR subjects through 2 years compared with 48.7% ± 5.9% of control subjects (P = .01). Cox regression analysis found an inverse correlation between number of hostile neck criteria met and later sac regression (P = .05). Preoperative neck thrombus circumference and infrarenal diameter were also variables associated with later sac regression, although not to a significant degree (P = .10 and P = .06, respectively). Control subjects with thrombus were significantly less likely to experience later sac regression than those without thrombus (6% and 43%, respectively; P = .001). In ANCHOR subjects, rate of regression was not significantly different in subjects with or without thrombus (33% and 36%, respectively; P = .82). Control subjects with wide aortic necks (>28 mm) were observed to experience sac regression at a lower rate than subjects with smaller diameter necks (10% and 44%, respectively; P = .004). Wide neck and normal neck subjects implanted with EndoAnchors experienced later sac regression at roughly equivalent rates (44% and 33%, respectively; P = .50). In propensity-matched cohorts of subjects undergoing EVAR, the rate of sac regression in subjects treated with EndoAnchors was significantly higher. EndoAnchors may mitigate the adverse effect of wide infrarenal necks and neck thrombus on sac regression, although further studies are needed to evaluate the long-term effect of EndoAnchors. Copyright © 2017 Society for Vascular Surgery. Published by Elsevier Inc. All rights reserved.

Quality of life and symptomatic response to gastric neurostimulation for gastroparesis.

PubMed

Velanovich, Vic

2008-10-01

Gastroparesis can be a difficult problem with patients suffering from nausea, vomiting, bloating, and pain intractable to medical management. Gastric neurostimulation has been developed as an adjunctive treatment for patients with diabetic and idiopathic gastroparesis unresponsive to pharmacologic and dietary treatment. The purpose of this study is to report symptomatic and quality-of-life response to gastric neurostimulation. This study was approved by the institutional review board, and patients had informed consent. The gastric neurostimulation device (Enterra therapy, Medtronic, Inc., Minneapolis, MN, USA) is approved by the Food and Drug Administration under the Humanitarian Device Exemption. Candidates for placement were patients with either idiopathic or diabetic gastroparesis who had symptomatic failure to dietary changes and to prokinetic and antiemetic drugs. Before placement, the patients' symptoms were recorded, and patients completed the Gastrointestinal Symptom Rating Scale (GSRS, three domains: dyspeptic syndrome, indigestion syndrome, and bowel dysfunction syndrome) and the Short Form-36 (SF-36, eight domains: physical functioning, role-physical, role-emotional, bodily pain, vitality, mental health, social functioning, general health, plus a health transition item). The device was surgically placed using a hybrid laparoscopic/open technique. Patients were followed and adjustments made on the device until satisfactory symptom control was achieved. At that time, patients completed both the GSRS and SF-36, and comparisons were made to preoperative values. Forty-two patients had the device placed, 29 women, aged 41 (SD +14) years, 24 diabetic patients, 17 idiopathic patients, one postgastrectomy patient. Median follow-up was 12 months (range 1-42 months). There was a 2% immediate postoperative morbidity rate and 7% long-term morbidity rate (device extrusion). Thirty-one patients (74%) responded to gastric neurostimulation of variable degrees. Eleven patients had no response or had worsening symptoms. Of the patients who responded, there were statistically significant improvements in all three domains of the GSRS. Median scores (with interquartile ranges): dyspeptic syndrome, 9 (7-11.5) to 4 (2.5-6), p = 0.02; indigestion syndrome, 5 (2-7) to 4 (0-5), p = 0.05; bowel dysfunction syndrome, 3 (2-3) to 1 (0-1), p = 0.01. In the SF-36, there were statistically significant improvement in the health transition item, 4 (4-5) to 1.5 (1-3), p = 0.01; and social functioning domain, 25 (12.5-62.5) to 75 (50-87.5), p = 0.03. Three quarters of gastroparesis patients responded to gastric neurostimulation to variable degrees. Gastrointestinal-specific symptoms are improved in responders. Patients felt that there health and social functioning (SF) improved, although there was no significant difference in the other domains. These results are encouraging considering that these patients had intractable symptoms with no other effective treatments available.

Mid- and long-term device migration after endovascular abdominal aortic aneurysm repair: a comparison of AneuRx and Zenith endografts.

PubMed

Tonnessen, Britt H; Sternbergh, W Charles; Money, Samuel R

2005-09-01

Freedom from migration is key to the durability of endovascular aneurysm repair (EVAR). This study evaluates the mid- and long-term incidence of migration with two different endografts. Between September 1997 and June 2004, 235 patients were scheduled for EVAR with an AneuRx (Medtronic/AVE Inc.) or Zenith (Cook) endograft. Patients with fusiform, infrarenal aneurysms and a minimum 12 months of follow-up were analyzed, for a final cohort of 130 patients. Migration was assessed on axial computed tomography (CT) (2.5 to 3 mm cuts) as the distance from the most caudal renal artery to the first slice containing endograft (AneuRx) or to the top of the bare suprarenal stent (Zenith). Aortic neck diameters were measured at the most caudal renal artery. The initial postoperative CT scan was the baseline. Migration was defined by caudal movement of the endograft at two thresholds, > or =5 mm and > or =10 mm, or any migration with a related clinical event. Life-table analysis demonstrated AneuRx freedom from migration (> or =10 mm or clinical event) was 96.1%, 89.5%, 78.0%, and 72.0% at 1, 2, 3, and 4 years, respectively. Zenith freedom from migration was 100%, 97.6%, 97.6%, and 97.6% at 1, 2, 3, and 4 years, respectively (P = .01, log-rank test). The stricter 5-mm migration threshold found 67.4% of AneuRx and 90.1% of Zenith patients free from migration at 4 years of follow-up. Twelve out of 14 (85.7%) AneuRx patients (12/14) with migration (> or =10 mm or clinical event) underwent 14 related secondary procedures (13 endovascular, 1 open conversion). The single Zenith patient with migration (> or =10 mm) has not required adjuvant treatment. Mean follow-up was 39.0 +/- 2.3 months (AneuRx) and 30.8 +/- 1.9 months (Zenith, P = .01). Patients with and without migration did not differ in age, gender ratio, aneurysm diameter, and neck diameter. However, initial neck length was shorter in patients with migration (22.1 +/- 2.1 mm vs 31.2 +/- 1.2 mm, P = .02). A subset of patients (21.6%) experienced significant (defined as > or =3 mm) maximum aortic neck dilation. Of the AneuRx patients, > or =3 mm aortic neck dilation affected 30.8% of migrators vs 13.0% of nonmigrators (P = .20). Endograft migration is a time-dependent phenomenon affected by both device choice and aortic neck length. A great majority of patients (85.7%) with migration of the AneuRx device ultimately required treatment. A minority of patients experienced aortic neck dilation that could be considered clinically significant. Careful surveillance for migration is an essential component of long-term follow-up after EVAR.

Height restoration of osteoporotic vertebral compression fractures using different intravertebral reduction devices: a cadaveric study.

PubMed

Krüger, Antonio; Oberkircher, Ludwig; Figiel, Jens; Floßdorf, Felix; Bolzinger, Florent; Noriega, David C; Ruchholtz, Steffen

2015-05-01

The treatment of osteoporotic vertebral compression fractures using transpedicular cement augmentation has grown significantly during the past two decades. Balloon kyphoplasty was developed to restore vertebral height and improve sagittal alignment. Several studies have shown these theoretical improvements cannot be transferred universally to the clinical setting. The aim of the current study is to evaluate two different procedures used for percutaneous augmentation of vertebral compression fractures with respect to height restoration: balloon kyphoplasty and SpineJack. Twenty-four vertebral bodies of two intact, fresh human cadaveric spines (T6-L5; donor age, 70 years and 60 years; T-score -6.8 points and -6.3 points) were scanned using computed tomography (CT) and dissected into single vertebral bodies. Vertebral wedge compression fractures were created by a material testing machine (Universal testing machine, Instron 5566, Darmstadt, Germany). The axial load was increased continuously until the height of the anterior edge of the vertebral body was reduced by 40% of the initial measured values. After 15 minutes, the load was decreased manually to 100 N. After postfracture CT, the clamped vertebral bodies were placed in a custom-made loading frame with a preload of 100 N. Twelve vertebral bodies were treated using SpineJack (SJ; Vexim, Balma, France), the 12 remaining vertebral bodies were treated with balloon kyphoplasty (BKP; Kyphon, Medtronic, Sunnyvale, CA, USA). The load was maintained during the procedure until the cement set completely. Posttreatment CT was performed. Anterior, central, and posterior height as well as the Beck index were measured prefracture and postfracture as well as after treatment. For anterior height restoration (BKP, 0.14±1.48 mm; SJ, 3.34±1.19 mm), central height restoration (BKP, 0.91±1.04 mm; SJ, 3.24±1.22 mm), and posterior restoration (BKP, 0.37±0.57 mm; SJ, 1.26±1.05), as well as the Beck index (BKP, 0.00±0.06 mm; SJ, 0.10±0.06), the values for the SpineJack group were significantly higher (p<.05) CONCLUSION: The protocols for creating wedge fractures and using the instrumentation under a constant preload of 100 N led to reproducible results and effects. The study showed that height restoration was significantly better in the SpineJack group compared with the balloon kyphoplasty group. The clinical implications include a better restoration of the sagittal balance of the spine and a reduction of the kyphotic deformity, which may relate to clinical outcome and the biological healing process. Copyright © 2015 Elsevier Inc. All rights reserved.

Constant Current versus Constant Voltage Subthalamic Nucleus Deep Brain Stimulation in Parkinson's Disease.

PubMed

Ramirez de Noriega, Fernando; Eitan, Renana; Marmor, Odeya; Lavi, Adi; Linetzky, Eduard; Bergman, Hagai; Israel, Zvi

2015-02-18

Background: Subthalamic nucleus (STN) deep brain stimulation (DBS) is an established therapy for advanced Parkinson's disease (PD). Motor efficacy and safety have been established for constant voltage (CV) devices and more recently for constant current (CC) devices. CC devices adjust output voltage to provide CC stimulation irrespective of impedance fluctuation, while the current applied by CV stimulation depends on the impedance that may change over time. No study has directly compared the clinical effects of these two stimulation modalities. Objective: To compare the safety and clinical impact of CC STN DBS to CV STN DBS in patients with advanced PD 2 years after surgery. Methods: Patients were eligible for inclusion if they had undergone STN DBS surgery for idiopathic PD, had been implanted with a Medtronic Activa PC and if their stimulation program and medication had been stable for at least 1 year. This single-center trial was designed as a double-blind, randomized, prospective study with crossover after 2 weeks. Motor equivalence of the 2 modalities was confirmed utilizing part III of the Unified Parkinson's Disease Rating Scale (UPDRS). PD diaries and multiple subjective and objective evaluations of quality of life, depression, cognition and emotional processing were evaluated on both CV and on CC stimulation. Analysis using the paired t test with Bonferroni correction for multiple comparisons was performed to identify any significant difference between the stimulation modalities. Results: 8 patients were recruited (6 men, 2 women); 1 patient did not complete the study. The average age at surgery was 56.7 years (range 47-63). Disease duration at the time of surgery was 7.5 years (range 3-12). Patients were recruited 23.8 months (range 22.5-24) after surgery. At the postoperative study baseline, this patient group showed an average motor improvement of 69% (range 51-97) as measured by the change in UPDRS part III with stimulation alone. Levodopa equivalent medication was reduced on average by 67% (range 15-88). Patients were poorly compliant with PD diaries, and these did not yield useful information. The minor deterioration in quality-of-life scores (Parkinson's Disease Questionnaire-39, Quality of Life Enjoyment and Satisfaction Questionnaire) with CC stimulation were not statistically significant. Two measures of depression (Hamilton Rating Scale D17, Quick Inventory of Depressive Symptomatology - Self-Report) showed a nonsignificant lower score (less depression) with CC stimulation, but a third (Beck Depression Inventory) showed equivalence. Cognitive testing (Mini Mental State Examination) and emotional processing (Montreal Affective Voices) were equivalent for CC and CV. Conclusion: CC STN DBS is safe. For equivalent motor efficacy, no significant difference could be identified between CC and CV stimulation for nonmotor evaluations in PD patients 2 years after surgery. © 2015 S. Karger AG, Basel.

Tricuspid Valve Repair for the Poor Right Ventricle: Tricuspid Valve Repair in Patients with Mild-to-Moderate Tricuspid Regurgitation Undergoing Mitral Valve Repair Improves In-Hospital Outcome.

PubMed

Zientara, Alicja; Genoni, Michele; Graves, Kirk; Odavic, Dragan; Löblein, Helen; Häussler, Achim; Dzemali, Omer

2017-12-01

Background  Tricuspid regurgitation (TR) in patients undergoing surgery for mitral valve (MV) increases morbidity and mortality, especially in case of a poor right ventricle. Does repair of mild-to-moderate insufficiency of the tricuspid valve (TV) in patients undergoing MV surgery lead to a benefit in early postoperative outcome? Methods  A total of 22 patients with mild-to-moderate TR underwent MV repair and concomitant TV repair with Tri-Ad (Medtronic ATS Medical Inc., Minneapolis, Minnesota, United States) and Edwards Cosgrove (Edwards Lifesciences Irvine, California, United States) rings. The severity of TR was assessed echocardiographically by using color-Doppler flow images. The tricuspid annular plane systolic excursion (TAPSE) was under 1.7 cm. Additional procedures included coronary artery bypass ( n  = 9) and maze procedure ( n  = 15). The following parameters were compared: postoperative and peak dose of noradrenaline (NA), pre/postoperative systolic pulmonary pressure (sPAP), extubation time, operation time, cross-clamp time, cardiopulmonary bypass (CPB) time, pre/postoperative ejection fraction (EF), intensive care unit (ICU)-stay, hospital stay, cell saver blood transfusion, intra/postoperative blood transfusion, and postoperative TR. Results  The mean age was 67 ± 14.8 years, 45% were male. Mean EF was 47 ± 16.2%, postoperative 52 ± 12.4%. sPAP was 46 ± 20.1 mm Hg preoperatively, sPAP was 40.6 ± 9.4 mm Hg postoperatively, NA postoperatively was 12 ± 10 μg/min, NA peak was 18 ± 11 μg/min, operation time was 275 ± 92 minutes, CPB was 145 ± 49 minutes, ICU stay was 2.4 ± 2.4 days, hospital stay was 10.8 ± 3.5 days, cell saver blood transfusion was 736 ± 346 mL, intraoperative transfusions were 2.5 ± 1.6. Two patients needed postoperative transfusions. A total of 19 patients were extubated at the 1st postoperative day, 2 patients at the 2nd day, and 1 at the 4th postoperative day. Two patients required a pacemaker. No reintubation, no in-hospital mortality, and one reoperation because of bleeding complications. Conclusion  Correction of mild-to-moderate TR at the time of MV repair does maintain TV function and avoid right ventricular dysfunction in the early postoperative period improving the clinical outcome. Georg Thieme Verlag KG Stuttgart · New York.

Integrating precision medicine in the study and clinical treatment of a severely mentally ill person

PubMed Central

O’Rawe, Jason A.; Fang, Han; Rynearson, Shawn; Robison, Reid; Kiruluta, Edward S.; Higgins, Gerald; Eilbeck, Karen; Reese, Martin G.

2013-01-01

Background. In recent years, there has been an explosion in the number of technical and medical diagnostic platforms being developed. This has greatly improved our ability to more accurately, and more comprehensively, explore and characterize human biological systems on the individual level. Large quantities of biomedical data are now being generated and archived in many separate research and clinical activities, but there exists a paucity of studies that integrate the areas of clinical neuropsychiatry, personal genomics and brain-machine interfaces. Methods. A single person with severe mental illness was implanted with the Medtronic Reclaim® Deep Brain Stimulation (DBS) Therapy device for Obsessive Compulsive Disorder (OCD), targeting his nucleus accumbens/anterior limb of the internal capsule. Programming of the device and psychiatric assessments occurred in an outpatient setting for over two years. His genome was sequenced and variants were detected in the Illumina Whole Genome Sequencing Clinical Laboratory Improvement Amendments (CLIA)-certified laboratory. Results. We report here the detailed phenotypic characterization, clinical-grade whole genome sequencing (WGS), and two-year outcome of a man with severe OCD treated with DBS. Since implantation, this man has reported steady improvement, highlighted by a steady decline in his Yale-Brown Obsessive Compulsive Scale (YBOCS) score from ∼38 to a score of ∼25. A rechargeable Activa RC neurostimulator battery has been of major benefit in terms of facilitating a degree of stability and control over the stimulation. His psychiatric symptoms reliably worsen within hours of the battery becoming depleted, thus providing confirmatory evidence for the efficacy of DBS for OCD in this person. WGS revealed that he is a heterozygote for the p.Val66Met variant in BDNF, encoding a member of the nerve growth factor family, and which has been found to predispose carriers to various psychiatric illnesses. He carries the p.Glu429Ala allele in methylenetetrahydrofolate reductase (MTHFR) and the p.Asp7Asn allele in ChAT, encoding choline O-acetyltransferase, with both alleles having been shown to confer an elevated susceptibility to psychoses. We have found thousands of other variants in his genome, including pharmacogenetic and copy number variants. This information has been archived and offered to this person alongside the clinical sequencing data, so that he and others can re-analyze his genome for years to come. Conclusions. To our knowledge, this is the first study in the clinical neurosciences that integrates detailed neuropsychiatric phenotyping, deep brain stimulation for OCD and clinical-grade WGS with management of genetic results in the medical treatment of one person with severe mental illness. We offer this as an example of precision medicine in neuropsychiatry including brain-implantable devices and genomics-guided preventive health care. PMID:24109560

Single-centre experience with next-generation devices for transapical aortic valve implantation.

PubMed

Seiffert, Moritz; Conradi, Lenard; Kloth, Benjamin; Koschyk, Dietmar; Schirmer, Johannes; Schnabel, Renate B; Blankenberg, Stefan; Reichenspurner, Hermann; Diemert, Patrick; Treede, Hendrik

2015-01-01

Transcatheter aortic valve implantation (TAVI) has become an established procedure in patients with aortic stenosis and high surgical risk. Experience with first-generation transcatheter heart valves (THVs) is broad but limitations, e.g. paravalvular regurgitation, have been demonstrated. Much hope rests on the recently Conformité Européenne mark approved next-generation devices to improve results in these patients. However, apart from the initial approval studies, clinical data with these new devices are still scarce. We aimed to assess short-term outcomes of 200 consecutive patients who underwent transapical TAVI with next-generation THV at our institution. Transapical TAVI was performed in 200 consecutive patients 80.5±6.7 years old (38.5% female) at high surgical risk (log EuroSCORE 20.2±16.5%). Devices implanted were the Engager (Medtronic, Inc., Minneapolis, MN, USA; n=50), JenaValve (JenaValve Technology, Munich, Germany; n=88) and Symetis Acurate (Symetis SA, Ecublens, Switzerland; n=62) THV that were selected by the heart team on an individual basis. Data at baseline, during the procedure and follow-up were analysed according to standardized Valve Academic Research Consortium end points. Median follow-up was 219 days. Implantation was successful in 96.5% of cases. Valve function improved significantly with an increase in effective orifice area from 0.8±0.4 to 1.8±0.3 cm2 and a reduction in mean transvalvalvular gradients from 34.0±17.0 to 11.2±5.4 mmHg. Paravalvular regurgitation was none or trace in 70.3% of patients, Grade 1 in 26.1%, and Grade 2 in 3.5%. No patients developed aortic regurgitation>Grade 2. Major access site complications occurred in 6.5%, major stroke in 1.5% and stage-3 kidney injury in 2.5% of patients. A permanent pacemaker was implanted in 20.5% of patients overall and in 8.0% for a complete heart block. At 30-day follow-up 72.8% of patients were in New York Heart Association class I or II (10.5% at baseline). Overall survival was 91.5% at 30 days and 73.9% at 1 year. In a real-world clinical setting, next-generation transapical THV yielded positive haemodynamic results. The incidence of relevant paravalvular regurgitation was scarce in this group and clinical outcomes were encouraging during short-term follow-up. Long-term follow-up is required to investigate the durability of these new devices. © The Author 2014. Published by Oxford University Press on behalf of the European Association for Cardio-Thoracic Surgery. All rights reserved.

Effect of general anaesthesia on functional outcome in patients with anterior circulation ischaemic stroke having endovascular thrombectomy versus standard care: a meta-analysis of individual patient data.

PubMed

Campbell, Bruce C V; van Zwam, Wim H; Goyal, Mayank; Menon, Bijoy K; Dippel, Diederik W J; Demchuk, Andrew M; Bracard, Serge; White, Philip; Dávalos, Antoni; Majoie, Charles B L M; van der Lugt, Aad; Ford, Gary A; de la Ossa, Natalia Pérez; Kelly, Michael; Bourcier, Romain; Donnan, Geoffrey A; Roos, Yvo B W E M; Bang, Oh Young; Nogueira, Raul G; Devlin, Thomas G; van den Berg, Lucie A; Clarençon, Frédéric; Burns, Paul; Carpenter, Jeffrey; Berkhemer, Olvert A; Yavagal, Dileep R; Pereira, Vitor Mendes; Ducrocq, Xavier; Dixit, Anand; Quesada, Helena; Epstein, Jonathan; Davis, Stephen M; Jansen, Olav; Rubiera, Marta; Urra, Xabier; Micard, Emilien; Lingsma, Hester F; Naggara, Olivier; Brown, Scott; Guillemin, Francis; Muir, Keith W; van Oostenbrugge, Robert J; Saver, Jeffrey L; Jovin, Tudor G; Hill, Michael D; Mitchell, Peter J

2018-01-01

General anaesthesia (GA) during endovascular thrombectomy has been associated with worse patient outcomes in observational studies compared with patients treated without GA. We assessed functional outcome in ischaemic stroke patients with large vessel anterior circulation occlusion undergoing endovascular thrombectomy under GA, versus thrombectomy not under GA (with or without sedation) versus standard care (ie, no thrombectomy), stratified by the use of GA versus standard care. For this meta-analysis, patient-level data were pooled from all patients included in randomised trials in PuMed published between Jan 1, 2010, and May 31, 2017, that compared endovascular thrombectomy predominantly done with stent retrievers with standard care in anterior circulation ischaemic stroke patients (HERMES Collaboration). The primary outcome was functional outcome assessed by ordinal analysis of the modified Rankin scale (mRS) at 90 days in the GA and non-GA subgroups of patients treated with endovascular therapy versus those patients treated with standard care, adjusted for baseline prognostic variables. To account for between-trial variance we used mixed-effects modelling with a random effect for trials incorporated in all models. Bias was assessed using the Cochrane method. The meta-analysis was prospectively designed, but not registered. Seven trials were identified by our search; of 1764 patients included in these trials, 871 were allocated to endovascular thrombectomy and 893 were assigned standard care. After exclusion of 74 patients (72 did not undergo the procedure and two had missing data on anaesthetic strategy), 236 (30%) of 797 patients who had endovascular procedures were treated under GA. At baseline, patients receiving GA were younger and had a shorter delay between stroke onset and randomisation but they had similar pre-treatment clinical severity compared with patients who did not have GA. Endovascular thrombectomy improved functional outcome at 3 months both in patients who had GA (adjusted common odds ratio (cOR) 1·52, 95% CI 1·09-2·11, p=0·014) and in those who did not have GA (adjusted cOR 2·33, 95% CI 1·75-3·10, p<0·0001) versus standard care. However, outcomes were significantly better for patients who did not receive GA versus those who received GA (covariate-adjusted cOR 1·53, 95% CI 1·14-2·04, p=0·0044). The risk of bias and variability between studies was assessed to be low. Worse outcomes after endovascular thrombectomy were associated with GA, after adjustment for baseline prognostic variables. These data support avoidance of GA whenever possible. The procedure did, however, remain effective versus standard care in patients treated under GA, indicating that treatment should not be withheld in those who require anaesthesia for medical reasons. Medtronic. Copyright © 2018 Elsevier Ltd. All rights reserved.

Safety and efficacy of thrombectomy in acute ischaemic stroke (REVASCAT): 1-year follow-up of a randomised open-label trial.

PubMed

Dávalos, Antoni; Cobo, Erik; Molina, Carlos A; Chamorro, Angel; de Miquel, M Angeles; Román, Luis San; Serena, Joaquín; López-Cancio, Elena; Ribó, Marc; Millán, Mónica; Urra, Xabier; Cardona, Pere; Tomasello, Alejandro; Castaño, Carlos; Blasco, Jordi; Aja, Lucía; Rubiera, Marta; Gomis, Meritxell; Renú, Arturo; Lara, Blanca; Martí-Fàbregas, Joan; Jankowitz, Brian; Cerdà, Neus; Jovin, Tudor G

2017-05-01

The REVASCAT trial and other studies have shown that the neurovascular thrombectomy improves outcomes at 90 days post stroke. However, whether the observed benefit is sustained in the long term remains unknown. We report the results of the prespecified 12-month analysis of the REVASCAT trial. Patients with acute ischaemic stroke who could be treated within 8 h of symptom onset were randomly assigned to medical therapy (including intravenous alteplase when eligible) and neurovascular thrombectomy with Solitaire FR or medical therapy alone. The main secondary outcome measure at 1 year follow-up was disability, measured using the modified Rankin Scale (mRS), ranging from 0 (no symptoms) to 6 (death) with categories 5 (severe disability) and 6 (death) collapsed into one category (severe disability or death), analysed as the distribution of the mRS. Additional prespecified secondary outcome measures included health-related quality of life measured with the EuroQol five dimensions questionnaire (EQ-5D) utility index (ranging from -0·3 to 1, higher values indicate better quality of life), the rate of functional independence (mRS 0-2), and cognitive function measured with the Trail Making Test (reported elsewhere). Treatment allocation was open label but endpoints at 12 months were assessed by masked investigators. The trial was registered at ClinicalTrials.gov, number NCT01692379. From Nov 24, 2012, to Dec 12, 2014, 206 patients were randomly assigned to medical therapy plus endovascular treatment (n=103) or medical treatment alone (n=103), at four centres in Catalonia, Spain. At 12 months post randomisation, based on 205 of 206 outcomes available at 12 months, thrombectomy reduced disability over the range of the mRS (common adjusted odds ratio [aOR] 1·80, 95% CI 1·09-2·99), and improved functional independence (mRS=0-2; 45 [44%] of 103 patients vs 31 [30%] of 103 patients; aOR 1·86, 95% CI 1·01-3·44). Health-related quality of life was superior in the thrombectomy group (mean EQ-5D utility index score, 0·46 [SD 0·38] in the thrombectomy group vs 0·33 [0·33] in the control group, difference 0·12 [95% CI 0·03-0·22]; p=0·01). 1-year mortality was 23% (24 of 103 patients) in the thrombectomy group versus 24% (25 of 103 patients) in the control group. At 12 months follow-up, neurovascular thrombectomy reduced post-stroke disability and improved health-related quality of life, indicating sustained benefit. These findings have important clinical and public health implications for evaluating the cost-effectiveness of the intervention in the long term. Fundació Ictus Malaltia Vascular through an unrestricted grant from Medtronic. Copyright © 2017 Elsevier Ltd. All rights reserved.

Glucose Outcomes with the In-Home Use of a Hybrid Closed-Loop Insulin Delivery System in Adolescents and Adults with Type 1 Diabetes

PubMed Central

Weinzimer, Stuart A.; Tamborlane, William V.; Buckingham, Bruce A.; Bode, Bruce W.; Bailey, Timothy S.; Brazg, Ronald L.; Ilany, Jacob; Slover, Robert H.; Anderson, Stacey M.; Bergenstal, Richard M.; Grosman, Benyamin; Roy, Anirban; Cordero, Toni L.; Shin, John; Lee, Scott W.; Kaufman, Francine R.

2017-01-01

Abstract Background: The safety and effectiveness of the in-home use of a hybrid closed-loop (HCL) system that automatically increases, decreases, and suspends insulin delivery in response to continuous glucose monitoring were investigated. Methods: Adolescents (n = 30, ages 14–21 years) and adults (n = 94, ages 22–75 years) with type 1 diabetes participated in a multicenter (nine sites in the United States, one site in Israel) pivotal trial. The Medtronic MiniMed® 670G system was used during a 2-week run-in phase without HCL control, or Auto Mode, enabled (Manual Mode) and, thereafter, with Auto Mode enabled during a 3-month study phase. A supervised hotel stay (6 days/5 nights) that included a 24-h frequent blood sample testing with a reference measurement (i-STAT) occurred during the study phase. Results: Adolescents (mean ± standard deviation [SD] 16.5 ± 2.29 years of age and 7.7 ± 4.15 years of diabetes) used the system for a median 75.8% (interquartile range [IQR] 68.0%–88.4%) of the time (2977 patient-days). Adults (mean ± SD 44.6 ± 12.79 years of age and 26.4 ± 12.43 years of diabetes) used the system for a median 88.0% (IQR 77.6%–92.7%) of the time (9412 patient-days). From baseline run-in to the end of study phase, adolescent and adult HbA1c levels decreased from 7.7% ± 0.8% to 7.1% ± 0.6% (P < 0.001) and from 7.3% ± 0.9% to 6.8% ± 0.6% (P < 0.001, Wilcoxon signed-rank test), respectively. The proportion of overall in-target (71–180 mg/dL) sensor glucose (SG) values increased from 60.4% ± 10.9% to 67.2% ± 8.2% (P < 0.001) in adolescents and from 68.8% ± 11.9% to 73.8% ± 8.4% (P < 0.001) in adults. During the hotel stay, the proportion of in-target i-STAT® blood glucose values was 67.4% ± 27.7% compared to SG values of 72.0% ± 11.6% for adolescents and 74.2% ± 17.5% compared to 76.9% ± 8.3% for adults. There were no severe hypoglycemic or diabetic ketoacidosis events in either cohort. Conclusions: HCL therapy was safe during in-home use by adolescents and adults and the study phase demonstrated increased time in target, and reductions in HbA1c, hyperglycemia and hypoglycemia, compared to baseline. Trial Registration: Clinicaltrials.gov identifier: NCT02463097. PMID:28134564

Anterior cement augmentation of adjacent levels after vertebral body replacement leads to superior stability of the corpectomy cage under cyclic loading-a biomechanical investigation.

PubMed

Oberkircher, Ludwig; Krüger, Antonio; Hörth, Dominik; Hack, Juliana; Ruchholtz, Steffen; Fleege, Christoph; Rauschmann, Michael; Arabmotlagh, Mohammad

2018-03-01

In the operative treatment of osteoporotic vertebral body fractures, a dorsal stabilization in combination with a corpectomy of the fractured vertebral body might be necessary with respect to the fracture morphology, whereby the osteoporotic bone quality may possibly increase the risk of implant failure. To achieve better stability, it is recommended to use cement-augmented screws for dorsal instrumentation. Besides careful end plate preparation, cement augmentation of the adjacent end plates has also been reported to lead to less reduction loss. The aim of the study was to evaluate biomechanically under cyclic loading whether an additional cement augmentation of the adjacent end plates leads to improved stability of the inserted cage. Methodical cadaver study. Fourteen fresh frozen human thoracic spines with proven osteoporosis were used (T2-T7). After removal of the soft tissues, the spine was embedded in Technovit (Kulzer, Germany). Subsequently, a corpectomy of T5 was performed, leaving the dorsal ligamentary structures intact. After randomization with respect to bone quality, two groups were generated: Dorsal instrumentation (cemented pedicle screws, Medtronic, Minneapolis, MN, USA)+cage implantation (CAPRI Corpectomy Cage, K2M, Leesburg, VA, USA) without additional cementation of the adjacent endplates (Group A) and dorsal instrumentation+cage implantation with additional cement augmentation of the adjacent end plates (Group B). The subsequent axial and cyclic loading was performed at a frequency of 1 Hz, starting at 400 N and increasing the load within 200 N after every 500 cycles up to a maximum of 2,200 N. Load failure was determined when the cages sintered macroscopically into the end plates (implant failure) or when the maximum load was reached. One specimen in Group B could not be clamped appropriately into the test bench for axial loading because of a pronounced scoliotic misalignment and had to be excluded. The mean strength for implant failure was 1,000 N±258.2 N in Group A (no cement augmentation of the adjacent end plates, n=7); on average, 1,622.1±637.6 cycles were achieved. In Group B (cement augmentation of the adjacent end plates, n=6), the mean force at the end of loading was 1,766.7 N±320.4 N; an average of 3,572±920.6 cycles was achieved. Three specimens reached a load of 2,000 N. The differences between the two groups were significant (p=.006 and p=.0047) regarding load failure and number of cycles. Additional cement augmentation of the adjacent end plates during implantation of a vertebral body replacement in osteoporotic bone resulted in a significant increased stability of the cage in the axial cyclic loading test. Copyright © 2017 Elsevier Inc. All rights reserved.

Insulin pump treatment compared with multiple daily injections for treatment of type 2 diabetes (OpT2mise): a randomised open-label controlled trial.

PubMed

Reznik, Yves; Cohen, Ohad; Aronson, Ronnie; Conget, Ignacio; Runzis, Sarah; Castaneda, Javier; Lee, Scott W

2014-10-04

Many patients with advanced type 2 diabetes do not meet their glycated haemoglobin targets and randomised controlled studies comparing the efficacy of pump treatment and multiple daily injections for lowering glucose in insulin-treated patients have yielded inconclusive results. We aimed to resolve this uncertainty with a randomised controlled trial (OpT2mise). We did this multicentre, controlled trial at 36 hospitals, tertiary care centres, and referal centres in Canada, Europe, Israel, South Africa, and the USA. Patients with type 2 diabetes who had poor glycaemic control despite multiple daily injections with insulin analogues were enrolled into a 2-month dose-optimisation run-in period. After the run-in period, patients with glycated haemoglobin of 8·0-12·0% (64-108 mmol/mol) were randomly assigned (1:1) by a computer-generated randomisation sequence (block size 2 with probability 0·75 and size 4 with probability 0·25) to pump treatment or to continue with multiple daily injections. Neither patients nor investigators were masked to treatment allocation. The primary endpoint was change in mean glycated haemoglobin between baseline and end of the randomised phase for the intention-to-treat population. This study is registered with ClinicalTrials.gov, number NCT01182493. 495 of 590 screened patients entered the run-in phase and 331 were randomised (168 to pump treatment, 163 to multiple daily injections). Mean glycated haemoglobin at baseline was 9% (75 mmol/mol) in both groups. At 6 months, mean glycated haemoglobin had decreased by 1·1% (SD 1·2; 12 mmol/mol, SD 13) in the pump treatment group and 0·4% (SD 1·1; 4 mmol/mol, SD 12) in the multiple daily injection group, resulting in a between-group treatment difference of -0·7% (95% CI -0·9 to -0·4; -8 mmol/mol, 95% CI -10 to -4, p<0·0001). At the end of the study, the mean total daily insulin dose was 97 units (SD 56) with pump treatment versus 122 units (SD 68) for multiple daily injections (p<0·0001), with no significant difference in bodyweight change between the two groups (1·5 kg [SD 3·5] vs 1·1 kg [3·6], p=0·322). Two diabetes-related serious adverse events (hyperglycaemia or ketosis without acidosis) resulting in hospital admission occurred in the pump treatment group compared with one in the multiple daily injection group. No ketoacidosis occurred in either group and one episode of severe hypoglycaemia occurred in the multiple daily injection group. In patients with poorly controlled type 2 diabetes despite using multiple daily injections of insulin, pump treatment can be considered as a safe and valuable treatment option. Medtronic. Copyright © 2014 Elsevier Ltd. All rights reserved.

Comparison of dual-hormone artificial pancreas, single-hormone artificial pancreas, and conventional insulin pump therapy for glycaemic control in patients with type 1 diabetes: an open-label randomised controlled crossover trial.

PubMed

Haidar, Ahmad; Legault, Laurent; Messier, Virginie; Mitre, Tina Maria; Leroux, Catherine; Rabasa-Lhoret, Rémi

2015-01-01

The artificial pancreas is an emerging technology for the treatment of type 1 diabetes and two configurations have been proposed: single-hormone (insulin alone) and dual-hormone (insulin and glucagon). We aimed to delineate the usefulness of glucagon in the artificial pancreas system. We did a randomised crossover trial of dual-hormone artificial pancreas, single-hormone artificial pancreas, and conventional insulin pump therapy (continuous subcutaneous insulin infusion) in participants aged 12 years or older with type 1 diabetes. Participants were assigned in a 1:1:1:1:1:1 ratio with blocked randomisation to the three interventions and attended a research facility for three 24-h study visits. During visits when the patient used the single-hormone artificial pancreas, insulin was delivered based on glucose sensor readings and a predictive dosing algorithm. During dual-hormone artificial pancreas visits, glucagon was also delivered during low or falling glucose. During conventional insulin pump therapy visits, patients received continuous subcutaneous insulin infusion. The study was not masked. The primary outcome was the time for which plasma glucose concentrations were in the target range (4·0-10·0 mmol/L for 2 h postprandially and 4·0-8·0 mmol/L otherwise). Hypoglycaemic events were defined as plasma glucose concentration of less than 3·3 mmol/L with symptoms or less than 3·0 mmol/L irrespective of symptoms. Analysis was by modified intention to treat, in which we included data for all patients who completed at least two visits. A p value of less than 0·0167 (0·05/3) was regarded as significant. This trial is registered with ClinicalTrials.gov, number NCT01754337. The mean proportion of time spent in the plasma glucose target range over 24 h was 62% (SD 18), 63% (18), and 51% (19) with single-hormone artificial pancreas, dual-hormone artificial pancreas, and conventional insulin pump therapy, respectively. The mean difference in time spent in the target range between single-hormone artificial pancreas and conventional insulin pump therapy was 11% (17; p=0·002) and between dual-hormone artificial pancreas and conventional insulin pump therapy was 12% (21; p=0·00011). There was no difference (15; p=0·75) in the proportion of time spent in the target range between the single-hormone and dual-hormone artificial pancreas systems. There were 52 hypoglycaemic events with conventional insulin pump therapy (12 of which were symptomatic), 13 with the single-hormone artificial pancreas (five of which were symptomatic), and nine with the dual-hormone artificial pancreas (0 of which were symptomatic); the number of nocturnal hypoglycaemic events was 13 (0 symptomatic), 0, and 0, respectively. Single-hormone and dual-hormone artificial pancreas systems both provided better glycaemic control than did conventional insulin pump therapy. The single-hormone artificial pancreas might be sufficient for hypoglycaemia-free overnight glycaemic control. Canadian Diabetes Association; Fondation J A De Sève; Juvenile Diabetes Research Foundation; and Medtronic. Copyright © 2015 Elsevier Ltd. All rights reserved.

Breaking sitting with light activities vs structured exercise: a randomised crossover study demonstrating benefits for glycaemic control and insulin sensitivity in type 2 diabetes.

PubMed

Duvivier, Bernard M F M; Schaper, Nicolaas C; Hesselink, Matthijs K C; van Kan, Linh; Stienen, Nathalie; Winkens, Bjorn; Koster, Annemarie; Savelberg, Hans H C M

2017-03-01

We aimed to examine the effects of breaking sitting with standing and light-intensity walking vs an energy-matched bout of structured exercise on 24 h glucose levels and insulin resistance in patients with type 2 diabetes. In a randomised crossover study, 19 patients with type 2 diabetes (13 men/6 women, 63 ± 9 years old) who were not using insulin each followed three regimens under free-living conditions, each lasting 4 days: (1) Sitting: 4415 steps/day with 14 h sitting/day; (2) Exercise: 4823 steps/day with 1.1 h/day of sitting replaced by moderate- to vigorous-intensity cycling (at an intensity of 5.9 metabolic equivalents [METs]); and (3) Sit Less: 17,502 steps/day with 4.7 h/day of sitting replaced by standing and light-intensity walking (an additional 2.5 h and 2.2 h, respectively, compared with the hours spent doing these activities in the Sitting regimen). Blocked randomisation was performed using a block size of six regimen orders using sealed, non-translucent envelopes. Individuals who assessed the outcomes were blinded to group assignment. Meals were standardised during each intervention. Physical activity and glucose levels were assessed for 24 h/day by accelerometry (activPAL) and a glucose monitor (iPro2), respectively. The incremental AUC (iAUC) for 24 h glucose (primary outcome) and insulin resistance (HOMA2-IR) were assessed on days 4 and 5, respectively. The iAUC for 24 h glucose (mean ± SEM) was significantly lower during the Sit Less intervention than in Sitting (1263 ± 189 min × mmol/l vs 1974 ± 324 min × mmol/l; p = 0.002), and was similar between Sit Less and Exercise (Exercise: 1383 ± 194 min × mmol/l; p = 0.499). Exercise failed to improve HOMA2-IR compared with Sitting (2.06 ± 0.28 vs 2.16 ± 0.26; p = 0.177). In contrast, Sit Less (1.89 ± 0.26) significantly reduced HOMA2-IR compared with Exercise (p = 0.015) as well as Sitting (p = 0.001). Breaking sitting with standing and light-intensity walking effectively improved 24 h glucose levels and improved insulin sensitivity in individuals with type 2 diabetes to a greater extent than structured exercise. Thus, our results suggest that breaking sitting with standing and light-intensity walking may be an alternative to structured exercise to promote glycaemic control in patients type 2 diabetes. Clinicaltrials.gov NCT02371239 FUNDING: : The study was supported by a Kootstra grant from Maastricht University Medical Centre + , and the Dutch Heart Foundation. Financial support was also provided by Novo Nordisk BV, and Medtronic and Roche made the equipment available for continuous glucose monitoring.

Catheter-based renal denervation in patients with uncontrolled hypertension in the absence of antihypertensive medications (SPYRAL HTN-OFF MED): a randomised, sham-controlled, proof-of-concept trial.

PubMed

Townsend, Raymond R; Mahfoud, Felix; Kandzari, David E; Kario, Kazuomi; Pocock, Stuart; Weber, Michael A; Ewen, Sebastian; Tsioufis, Konstantinos; Tousoulis, Dimitrios; Sharp, Andrew S P; Watkinson, Anthony F; Schmieder, Roland E; Schmid, Axel; Choi, James W; East, Cara; Walton, Anthony; Hopper, Ingrid; Cohen, Debbie L; Wilensky, Robert; Lee, David P; Ma, Adrian; Devireddy, Chandan M; Lea, Janice P; Lurz, Philipp C; Fengler, Karl; Davies, Justin; Chapman, Neil; Cohen, Sidney A; DeBruin, Vanessa; Fahy, Martin; Jones, Denise E; Rothman, Martin; Böhm, Michael

2017-11-11

Previous randomised renal denervation studies did not show consistent efficacy in reducing blood pressure. The objective of our study was to evaluate the effect of renal denervation on blood pressure in the absence of antihypertensive medications. SPYRAL HTN-OFF MED was a multicentre, international, single-blind, randomised, sham-controlled, proof-of-concept trial. Patients were enrolled at 21 centres in the USA, Europe, Japan, and Australia. Eligible patients were drug-naive or discontinued their antihypertensive medications. Patients with an office systolic blood pressure (SBP) of 150 mm Hg or greater and less than 180 mm Hg, office diastolic blood pressure (DBP) of 90 mm Hg or greater, and a mean 24-h ambulatory SBP of 140 mm Hg or greater and less than 170 mm Hg at second screening underwent renal angiography and were randomly assigned to renal denervation or sham control. Patients, caregivers, and those assessing blood pressure were blinded to randomisation assignments. The primary endpoint, change in 24-h blood pressure at 3 months, was compared between groups. Drug surveillance was done to ensure patient compliance with absence of antihypertensive medication. The primary analysis was done in the intention-to-treat population. Safety events were assessed at 3 months. This study is registered with ClinicalTrials.gov, number NCT02439749. Between June 25, 2015, and Jan 30, 2017, 353 patients were screened. 80 patients were randomly assigned to renal denervation (n=38) or sham control (n=42) and followed up for 3 months. Office and 24-h ambulatory blood pressure decreased significantly from baseline to 3 months in the renal denervation group: 24-h SBP -5·5 mm Hg (95% CI -9·1 to -2·0; p=0·0031), 24-h DBP -4·8 mm Hg (-7·0 to -2·6; p<0·0001), office SBP -10·0 mm Hg (-15·1 to -4·9; p=0·0004), and office DBP -5·3 mm Hg (-7·8 to -2·7; p=0·0002). No significant changes were seen in the sham-control group: 24-h SBP -0·5 mm Hg (95% CI -3·9 to 2·9; p=0·7644), 24-h DBP -0·4 mm Hg (-2·2 to 1·4; p=0·6448), office SBP -2·3 mm Hg (-6·1 to 1·6; p=0·2381), and office DBP -0·3 mm Hg (-2·9 to 2·2; p=0·8052). The mean difference between the groups favoured renal denervation for 3-month change in both office and 24-h blood pressure from baseline: 24-h SBP -5·0 mm Hg (95% CI -9·9 to -0·2; p=0·0414), 24-h DBP -4·4 mm Hg (-7·2 to -1·6; p=0·0024), office SBP -7·7 mm Hg (-14·0 to -1·5; p=0·0155), and office DBP -4·9 mm Hg (-8·5 to -1·4; p=0·0077). Baseline-adjusted analyses showed similar findings. There were no major adverse events in either group. Results from SPYRAL HTN-OFF MED provide biological proof of principle for the blood-pressure-lowering efficacy of renal denervation. Medtronic. Copyright © 2017 Elsevier Ltd. All rights reserved.

Budget Impact of Adding Ivabradine to Standard of Care in Patients with Chronic Systolic Heart Failure in the United States.

PubMed

Borer, Jeffrey S; Kansal, Anuraag R; Dorman, Emily D; Krotneva, Stanimira; Zheng, Ying; Patel, Harshali K; Tavazzi, Luigi; Komajda, Michel; Ford, Ian; Böhm, Michael; Kielhorn, Adrian

2016-09-01

Heart failure (HF) costs $21 billion annually in direct health care costs, 80% of which is directly attributable to hospitalizations. The SHIFT clinical study demonstrated that ivabradine plus standard of care (SoC) reduced HF-related and all-cause hospitalizations compared with SoC alone. To estimate the budget impact of ivabradine from a U.S. commercial payer perspective. A budget impact model estimated the per-member-per month (PMPM) impact of introducing ivabradine to existing formularies by comparing a reference scenario (SoC) and a new drug scenario (ivabradine + SoC) in hypothetical 1 million-member commercial and Medicare Advantage plans. In both scenarios, U.S. claims data were used for the reference cumulative annual rates of hospitalizations (HF, non-HF cardiovascular [CV], and non-CV), and hospitalization rates were adjusted using SHIFT data. The model controlled for mortality risk using SHIFT and U.S. life table data, and hospitalization costs were obtained from U.S. claims data: HF-related = $37,507; non-HF CV = $28,951; and non-CV = $17,904. The annualized wholesale acquisition cost of ivabradine was $4,500, with baseline use for this new drug at 2%, increasing 2% per year. Based on the approved U.S. indication, approximately 2,000 commercially insured patients from a 1 million-member commercial plan were eligible to receive ivabradine. Ivabradine resulted in a PMPM cost savings of $0.01 and $0.04 in years 1 and 3 of the core model, respectively. After including the acquisition price for ivabradine, the model showed a decrease in total costs in the commercial ($991,256 and $474,499, respectively) and Medicare populations ($13,849,262 and $4,280,291, respectively) in year 1. This decrease was driven by ivabradine's reduction in hospitalization rates. For the core model, the estimated pharmacy-only PMPM in year 1 was $0.01 for the commercial population and $0.24 for the Medicare Advantage population. Adding ivabradine to SoC led to lower average annual treatment costs. The negative PMPM budget impact indicates that ivabradine is an affordable option for U.S. payers. This study was funded by Amgen. Patel is employed by Amgen; Kielhorn was employed by Amgen at the time of the study but is no longer affiliated with Amgen. Borer, Böhm, Ford, and Komajda have received scientific support, consultative fees, and/or speakers honoraria from Servier and Amgen in connection with SHIFT, the trial underlying this analysis. Borer also has received consultative fees from Celladon, Pfizer, ARMGO, Cardiorentis, Novartis, and Takeda USA. Kansal, Dorman, Krotneva, and Zheng are employees of Evidera, which was hired to assist with this study. Tavazzi has received research grants and consultation fees from Servier in connection with this study and has had advisory board memberships with Boston Scientific, Servier, Cardiorentis, Medtronic, St. Jude Medical, and CVie Therapeutics. Study concept and design were contributed by Dorman and Keilhorn, along with the other authors. Tavazzi, Komajda, Ford, BÖhm, and Borer oversaw collection of the data. Tavazzi, Komajda, Ford, BÖhm, and Borer (along with Karl Swedberg) formed the Executive Committee of SHIFT, the trial underlying this analysis. The manuscript was written by Kansal, along with the other authors, and revised by Borer and Patel, with assistance from the other authors.

Economic evaluation comparing intraoperative cone beam CT-based navigation and conventional fluoroscopy for the placement of spinal pedicle screws: a patient-level data cost-effectiveness analysis.

PubMed

Dea, Nicolas; Fisher, Charles G; Batke, Juliet; Strelzow, Jason; Mendelsohn, Daniel; Paquette, Scott J; Kwon, Brian K; Boyd, Michael D; Dvorak, Marcel F S; Street, John T

2016-01-01

Pedicle screws are routinely used in contemporary spinal surgery. Screw misplacement may be asymptomatic but is also correlated with potential adverse events. Computer-assisted surgery (CAS) has been associated with improved screw placement accuracy rates. However, this technology has substantial acquisition and maintenance costs. Despite its increasing usage, no rigorous full economic evaluation comparing this technology to current standard of care has been reported. Medical costs are exploding in an unsustainable way. Health economic theory requires that medical equipment costs be compared with expected benefits. To answer this question for computer-assisted spinal surgery, we present an economic evaluation looking specifically at symptomatic misplaced screws leading to reoperation secondary to neurologic deficits or biomechanical concerns. The study design was an observational case-control study from prospectively collected data of consecutive patients treated with the aid of CAS (treatment group) compared with a matched historical cohort of patients treated with conventional fluoroscopy (control group). The patient sample consisted of consecutive patients treated surgically at a quaternary academic center. The primary effectiveness measure studied was the number of reoperations for misplaced screws within 1 year of the index surgery. Secondary outcome measures included were total adverse event rate and postoperative computed tomography usage for pedicle screw examination. A patient-level data cost-effectiveness analysis from the hospital perspective was conducted to determine the value of a navigation system coupled with intraoperative 3-D imaging (O-arm Imaging and the StealthStation S7 Navigation Systems, Medtronic, Louisville, CO, USA) in adult spinal surgery. The capital costs for both alternatives were reported as equivalent annual costs based on the annuitization of capital expenditures method using a 3% discount rate and a 7-year amortization period. Annual maintenance costs were also added. Finally, reoperation costs using a micro-costing approach were calculated for both groups. An incremental cost-effectiveness ratio was calculated and reported as cost per reoperation avoided. Based on reoperation costs in Canada and in the United States, a minimal caseload was calculated for the more expensive alternative to be cost saving. Sensitivity analyses were also conducted. A total of 5,132 pedicle screws were inserted in 502 patients during the study period: 2,682 screws in 253 patients in the treatment group and 2,450 screws in 249 patients in the control group. Overall accuracy rates were 95.2% for the treatment group and 86.9% for the control group. Within 1 year post treatment, two patients (0.8%) required a revision surgery in the treatment group compared with 15 patients (6%) in the control group. An incremental cost-effectiveness ratio of $15,961 per reoperation avoided was calculated for the CAS group. Based on a reoperation cost of $12,618, this new technology becomes cost saving for centers performing more than 254 instrumented spinal procedures per year. Computer-assisted spinal surgery has the potential to reduce reoperation rates and thus to have serious cost-effectiveness and policy implications. High acquisition and maintenance costs of this technology can be offset by equally high reoperation costs. Our cost-effectiveness analysis showed that for high-volume centers with a similar case complexity to the studied population, this technology is economically justified. Copyright © 2015 Elsevier Inc. All rights reserved.

Endovascular thrombectomy after large-vessel ischaemic stroke: a meta-analysis of individual patient data from five randomised trials.

PubMed

Goyal, Mayank; Menon, Bijoy K; van Zwam, Wim H; Dippel, Diederik W J; Mitchell, Peter J; Demchuk, Andrew M; Dávalos, Antoni; Majoie, Charles B L M; van der Lugt, Aad; de Miquel, Maria A; Donnan, Geoffrey A; Roos, Yvo B W E M; Bonafe, Alain; Jahan, Reza; Diener, Hans-Christoph; van den Berg, Lucie A; Levy, Elad I; Berkhemer, Olvert A; Pereira, Vitor M; Rempel, Jeremy; Millán, Mònica; Davis, Stephen M; Roy, Daniel; Thornton, John; Román, Luis San; Ribó, Marc; Beumer, Debbie; Stouch, Bruce; Brown, Scott; Campbell, Bruce C V; van Oostenbrugge, Robert J; Saver, Jeffrey L; Hill, Michael D; Jovin, Tudor G

2016-04-23

In 2015, five randomised trials showed efficacy of endovascular thrombectomy over standard medical care in patients with acute ischaemic stroke caused by occlusion of arteries of the proximal anterior circulation. In this meta-analysis we, the trial investigators, aimed to pool individual patient data from these trials to address remaining questions about whether the therapy is efficacious across the diverse populations included. We formed the HERMES collaboration to pool patient-level data from five trials (MR CLEAN, ESCAPE, REVASCAT, SWIFT PRIME, and EXTEND IA) done between December, 2010, and December, 2014. In these trials, patients with acute ischaemic stroke caused by occlusion of the proximal anterior artery circulation were randomly assigned to receive either endovascular thrombectomy within 12 h of symptom onset or standard care (control), with a primary outcome of reduced disability on the modified Rankin Scale (mRS) at 90 days. By direct access to the study databases, we extracted individual patient data that we used to assess the primary outcome of reduced disability on mRS at 90 days in the pooled population and examine heterogeneity of this treatment effect across prespecified subgroups. To account for between-trial variance we used mixed-effects modelling with random effects for parameters of interest. We then used mixed-effects ordinal logistic regression models to calculate common odds ratios (cOR) for the primary outcome in the whole population (shift analysis) and in subgroups after adjustment for age, sex, baseline stroke severity (National Institutes of Health Stroke Scale score), site of occlusion (internal carotid artery vs M1 segment of middle cerebral artery vs M2 segment of middle cerebral artery), intravenous alteplase (yes vs no), baseline Alberta Stroke Program Early CT score, and time from stroke onset to randomisation. We analysed individual data for 1287 patients (634 assigned to endovascular thrombectomy, 653 assigned to control). Endovascular thrombectomy led to significantly reduced disability at 90 days compared with control (adjusted cOR 2.49, 95% CI 1.76-3.53; p<0.0001). The number needed to treat with endovascular thrombectomy to reduce disability by at least one level on mRS for one patient was 2.6. Subgroup analysis of the primary endpoint showed no heterogeneity of treatment effect across prespecified subgroups for reduced disability (pinteraction=0.43). Effect sizes favouring endovascular thrombectomy over control were present in several strata of special interest, including in patients aged 80 years or older (cOR 3.68, 95% CI 1.95-6.92), those randomised more than 300 min after symptom onset (1.76, 1.05-2.97), and those not eligible for intravenous alteplase (2.43, 1.30-4.55). Mortality at 90 days and risk of parenchymal haematoma and symptomatic intracranial haemorrhage did not differ between populations. Endovascular thrombectomy is of benefit to most patients with acute ischaemic stroke caused by occlusion of the proximal anterior circulation, irrespective of patient characteristics or geographical location. These findings will have global implications on structuring systems of care to provide timely treatment to patients with acute ischaemic stroke due to large vessel occlusion. Medtronic. Copyright © 2016 Elsevier Ltd. All rights reserved.

Continuous glucose monitoring for patients with type 1 diabetes and impaired awareness of hypoglycaemia (IN CONTROL): a randomised, open-label, crossover trial.

PubMed

van Beers, Cornelis A J; DeVries, J Hans; Kleijer, Susanne J; Smits, Mark M; Geelhoed-Duijvestijn, Petronella H; Kramer, Mark H H; Diamant, Michaela; Snoek, Frank J; Serné, Erik H

2016-11-01

Patients with type 1 diabetes who have impaired awareness of hypoglycaemia have a three to six times increased risk of severe hypoglycaemia. We aimed to assess whether continuous glucose monitoring (CGM) improves glycaemia and prevents severe hypoglycaemia compared with self-monitoring of blood glucose (SMBG) in this high-risk population. We did a randomised, open-label, crossover trial (IN CONTROL) at two medical centres in the Netherlands. Eligible participants were patients diagnosed with type 1 diabetes according to American Diabetes Association criteria, aged 18-75 years, with impaired awareness of hypoglycaemia as confirmed by a Gold score of at least 4, and treated with either continuous subcutaneous insulin infusion or multiple daily insulin injections and doing at least three SMBG measurements per day. After screening, re-education about diabetes management, and a 6-week run-in phase (to obtain baseline CGM data), we randomly assigned patients (1:1) with a computer-generated allocation sequence (block size of four) to either 16 weeks of CGM followed by 12 weeks of washout and 16 weeks of SMBG, or 16 weeks of SMBG followed by 12 weeks of washout and 16 weeks of CGM (where the SMBG phase was the control). During the CGM phase, patients used a real-time CGM system consisting of a Paradigm Veo system with a MiniLink transmitter and an Enlite glucose sensor (Medtronic, CA, USA). During the SMBG phase, patients were equipped with a masked CGM device, consisting of an iPro 2 continuous glucose monitor and an Enlite glucose sensor, which does not display real-time glucose values. The number of SMBG measurements per day and SMBG systems were not standardised between patients, to mimic real-life conditions. During both intervention periods, patients attended follow-up visits at the centres each month and had telephone consultations 2 weeks after each visit inquiring about adverse events, episodes of hypoglycaemia, etc. The primary endpoint was the mean difference in percentage of time spent in normoglycaemia (4-10 mmol/L) over the total intervention periods, analysed on an intention-to-treat basis. Severe hypoglycaemia (requiring third party assistance) was a secondary endpoint. This trial is registered with ClinicalTrials.gov, number NCT01787903. Between March 4, 2013, and Feb 9, 2015, we recruited and randomly assigned 52 patients to either the CGM-SMBG sequence (n=26) or the SMBG-CGM sequence (n=26). The last patient visit was on March 21, 2016. Time spent in normoglycaemia was higher during CGM than during SMBG: 65·0% (95% CI 62·8-67·3) versus 55·4% (53·1-57·7; mean difference 9·6%, 95% CI 8·0-11·2; p<0·0001), with reductions in both time spent in hypoglycaemia (ie, blood glucose ≤3·9 mmol/L [6·8% vs 11·4%, mean difference 4·7%, 3·4-5·9; p<0·0001]) and time spent in hyperglycaemia (ie, blood glucose >10 mmol/L [28·2% vs 33·2%, mean difference 5·0%, 3·1-6·9; p<0·0001]). During CGM, the number of severe hypoglycaemic events was lower (14 events vs 34 events, p=0·033). Five serious adverse events other than severe hypoglycaemia occurred during the trial, but all were deemed unrelated to the trial intervention. Additionally, no mild to moderate adverse events were related to the trial intervention. CGM increased time spent in normoglycaemia and reduced severe hypoglycaemia in patients with type 1 diabetes and impaired awareness of hypoglycaemia, compared with SMBG. Our results support the concept of using CGM in this high-risk population. Eli Lilly and Sanofi. Copyright © 2016 Elsevier Ltd. All rights reserved.

Behavioural outcomes of subthalamic stimulation and medical therapy versus medical therapy alone for Parkinson's disease with early motor complications (EARLYSTIM trial): secondary analysis of an open-label randomised trial.

PubMed

Lhommée, Eugénie; Wojtecki, Lars; Czernecki, Virginie; Witt, Karsten; Maier, Franziska; Tonder, Lisa; Timmermann, Lars; Hälbig, Thomas D; Pineau, Fanny; Durif, Franck; Witjas, Tatiana; Pinsker, Marcus; Mehdorn, Maximilian; Sixel-Döring, Friederike; Kupsch, Andreas; Krüger, Rejko; Elben, Saskia; Chabardès, Stephan; Thobois, Stéphane; Brefel-Courbon, Christine; Ory-Magne, Fabienne; Regis, Jean-Marie; Maltête, David; Sauvaget, Anne; Rau, Jörn; Schnitzler, Alfons; Schüpbach, Michael; Schade-Brittinger, Carmen; Deuschl, Gunther; Houeto, Jean-Luc; Krack, Paul

2018-03-01

Although subthalamic stimulation is a recognised treatment for motor complications in Parkinson's disease, reports on behavioural outcomes are controversial, which represents a major challenge when counselling candidates for subthalamic stimulation. We aimed to assess changes in behaviour in patients with Parkinson's disease receiving combined treatment with subthalamic stimulation and medical therapy over a 2-year follow-up period as compared with the behavioural evolution under medical therapy alone. We did a parallel, open-label study (EARLYSTIM) at 17 surgical centres in France (n=8) and Germany (n=9). We recruited patients with Parkinson's disease who were disabled by early motor complications. Participants were randomly allocated (1:1) to either medical therapy alone or bilateral subthalamic stimulation plus medical therapy. The primary outcome was mean change in quality of life from baseline to 2 years. A secondary analysis was also done to assess behavioural outcomes. We used the Ardouin Scale of Behavior in Parkinson's Disease to assess changes in behaviour between baseline and 2-year follow-up. Apathy was also measured using the Starkstein Apathy Scale, and depression was assessed with the Beck Depression Inventory. The secondary analysis was done in all patients recruited. We used a generalised estimating equations (GEE) regression model for individual items and mixed model regression for subscores of the Ardouin scale and the apathy and depression scales. This trial is registered with ClinicalTrials.gov, number NCT00354133. The primary analysis has been reported elsewhere; this report presents the secondary analysis only. Between July, 2006, and November, 2009, 251 participants were recruited, of whom 127 were allocated medical therapy alone and 124 were assigned bilateral subthalamic stimulation plus medical therapy. At 2-year follow-up, the levodopa-equivalent dose was reduced by 39% (-363·3 mg/day [SE 41·8]) in individuals allocated bilateral subthalamic stimulation plus medical therapy and was increased by 21% (245·8 mg/day [40·4]) in those assigned medical therapy alone (p<0·0001). Neuropsychiatric fluctuations decreased with bilateral subthalamic stimulation plus medical therapy during 2-year follow-up (mean change -0·65 points [SE 0·15]) and did not change with medical therapy alone (-0·02 points [0·15]); the between-group difference in change from baseline was significant (p=0·0028). At 2 years, the Ardouin scale subscore for hyperdopaminergic behavioural disorders had decreased with bilateral subthalamic stimulation plus medical therapy (mean change -1·26 points [SE 0·35]) and had increased with medical therapy alone (1·12 points [0·35]); the between-group difference was significant (p<0·0001). Mean change from baseline at 2 years in the Ardouin scale subscore for hypodopaminergic behavioural disorders, the Starkstein Apathy Scale score, and the Beck Depression Inventory score did not differ between treatment groups. Antidepressants were stopped in 12 patients assigned bilateral subthalamic stimulation plus medical therapy versus four patients allocated medical therapy alone. Neuroleptics were started in nine patients assigned medical therapy alone versus one patient allocated bilateral subthalamic stimulation plus medical therapy. During the 2-year follow-up, two individuals assigned bilateral subthalamic stimulation plus medical therapy and one patient allocated medical therapy alone died by suicide. In a large cohort with Parkinson's disease and early motor complications, better overall behavioural outcomes were noted with bilateral subthalamic stimulation plus medical therapy compared with medical therapy alone. The presence of hyperdopaminergic behaviours and neuropsychiatric fluctuations can be judged additional arguments in favour of subthalamic stimulation if surgery is considered for disabling motor complications. German Federal Ministry of Education and Research, French Programme Hospitalier de Recherche Clinique National, and Medtronic. Copyright © 2018 Elsevier Ltd. All rights reserved.

Optimizing Anti-VEGF Treatment Outcomes for Patients with Neovascular Age-Related Macular Degeneration.

PubMed

Wykoff, Charles C; Clark, W Lloyd; Nielsen, Jared S; Brill, Joel V; Greene, Laurence S; Heggen, Cherilyn L

2018-02-01

The introduction of anti-vascular endothelial growth factor (anti-VEGF) drugs to ophthalmology has revolutionized the treatment of neovascular age-related macular degeneration (nAMD). Despite this significant progress, gaps and challenges persist in the diagnosis of nAMD, initiation of treatment, and management of frequent intravitreal injections. Thus, nAMD remains a leading cause of blindness in the United States. To present current knowledge, evidence, and expert perspectives on anti-VEGF therapies in nAMD to support managed care professionals and providers in decision making and collaborative strategies to overcome barriers to optimize anti-VEGF treatment outcomes among nAMD patients. Three anti-VEGF therapies currently form the mainstay of treatment for nAMD, including 2 therapies approved by the FDA for treatment of nAMD (aflibercept and ranibizumab) and 1 therapy approved by the FDA for oncology indications and used off-label for treatment of nAMD (bevacizumab). In clinical trials, each of the 3 agents maintained visual acuity (VA) in approximately 90% or more of nAMD patients over 2 years. However, in long-term and real-world settings, significant gaps and challenges in diagnosis, treatment, and management pose barriers to achieving optimal outcomes for patients with nAMD. Many considerations, including individual patient characteristics, on-label versus off-label treatment, repackaging, and financial considerations, add to the complexity of nAMD decision making and management. Many factors may contribute to additional challenges leading to suboptimal long-term outcomes among nAMD patients, such as delays in diagnosis and/or treatment approval and initiation, individual patient response to different anti-VEGF therapies, lapses in physician regimentation of anti-VEGF injection and monitoring, and inadequate patient adherence to treatment and monitoring. These latter factors highlight the considerable logistical, emotional, and financial burdens of long-term, frequent intravitreal injections and the vital importance of personalized approaches to anti-VEGF treatment decision making and management for patients with nAMD. To address these challenges and reduce the number of yearly injections, studies have examined alternative dosing regimens, including extended fixed intervals, as needed, and treat-and-extend strategies in specific nAMD patient populations. New clinical evidence and insights into expert clinical practice discussed in this article can support managed care professionals in the key role they play in addressing challenges in nAMD treatment and management and optimizing patient outcomes through appropriate management of anti-VEGF treatment. PRIME Education is an independent medical education company and has been an accredited provider of continuing education for 23 years. There is no fee for this activity as it is sponsored by PRIME through an educational grant from Regeneron. All authors contributed to the writing and reviewing of the article. Wykoff reports consultancies/research grants from Alcon Laboratories, Genentech/Roche, Clearside, and Iconic Therapeutics; consultancies/honoraria, research grants, and speaker fees from Allergan and Regeneron; research grants from Allegro, Apellis, Aura, NEI, NIH, Novartis, OHR Pharmaceuticals, Ophthotech, pSivida, Roche, Santen, SciFluor, Tyrogenex; and consultancies for Alimera Sciences, Alnylam Pharmaceuticals, Bayer, DORC, ONL Therapeutics, Thrombogenics, and Valeant. Clark reports advisory board work, consultancies, research grants, and speaker fees from Genentech/Roche and Regeneron and consultancy for Bayer. Brill reports consultancies for Aries Pharma, Avella, BaroNova, Braeburn Pharmaceuticals, Cardinal Health, Endogastric Solutions, GeneNews, Halt Medical, Lumendi, Medtronic, Monteris Medical, Natera, Phosphorus, Rebiotix, Seno Medical, UCB, Vermillion, Echosens, and HAP Innovations. Brill is a shareholder in EndoChoice, GeneNews, SonarMD, and SynerZ and reports advisory board work with Nestle Health Sciences, Indivior Pharmaceuticals, Eli Lilly, Blue Earth Diagnostics, Bayer, and AstraZeneca. Nielson reports advisory board work/consultancy and research grants for Genentech/Roche; advisory board work and research grants from Regeneron; and research grants from Alcon and Ophthotech.

Effect of renal denervation on blood pressure in the presence of antihypertensive drugs: 6-month efficacy and safety results from the SPYRAL HTN-ON MED proof-of-concept randomised trial.

PubMed

Kandzari, David E; Böhm, Michael; Mahfoud, Felix; Townsend, Raymond R; Weber, Michael A; Pocock, Stuart; Tsioufis, Konstantinos; Tousoulis, Dimitrios; Choi, James W; East, Cara; Brar, Sandeep; Cohen, Sidney A; Fahy, Martin; Pilcher, Garrett; Kario, Kazuomi

2018-06-09

Previous catheter-based renal denervation studies have reported variable efficacy results. We aimed to evaluate safety and blood pressure response after renal denervation or sham control in patients with uncontrolled hypertension on antihypertensive medications with drug adherence testing. In this international, randomised, single-blind, sham-control, proof-of-concept trial, patients with uncontrolled hypertension (aged 20-80 years) were enrolled at 25 centres in the USA, Germany, Japan, UK, Australia, Austria, and Greece. Eligible patients had an office systolic blood pressure of between 150 mm Hg and 180 mm Hg and a diastolic blood pressure of 90 mm Hg or higher; a 24 h ambulatory systolic blood pressure of between 140 mm Hg and 170 mm Hg at second screening; and were on one to three antihypertensive drugs with stable doses for at least 6 weeks. Patients underwent renal angiography and were randomly assigned to undergo renal denervation or sham control. Patients, caregivers, and those assessing blood pressure were masked to randomisation assignments. The primary efficacy endpoint was blood pressure change from baseline (measured at screening visit two), based on ambulatory blood pressure measurements assessed at 6 months, as compared between treatment groups. Drug surveillance was used to assess medication adherence. The primary analysis was done in the intention-to-treat population. Safety events were assessed through 6 months as per major adverse events. This trial is registered with ClinicalTrials.gov, number NCT02439775, and follow-up is ongoing. Between July 22, 2015, and June 14, 2017, 467 patients were screened and enrolled. This analysis presents results for the first 80 patients randomly assigned to renal denervation (n=38) and sham control (n=42). Office and 24 h ambulatory blood pressure decreased significantly from baseline to 6 months in the renal denervation group (mean baseline-adjusted treatment differences in 24 h systolic blood pressure -7·0 mm Hg, 95% CI -12·0 to -2·1; p=0·0059, 24 h diastolic blood pressure -4·3 mm Hg, -7·8 to -0·8; p=0.0174, office systolic blood pressure -6·6 mm Hg, -12·4 to -0·9; p=0·0250, and office diastolic blood pressure -4·2 mm Hg, -7·7 to -0·7; p=0·0190). The change in blood pressure was significantly greater at 6 months in the renal denervation group than the sham-control group for office systolic blood pressure (difference -6·8 mm Hg, 95% CI -12·5 to -1·1; p=0·0205), 24 h systolic blood pressure (difference -7·4 mm Hg, -12·5 to -2·3; p=0·0051), office diastolic blood pressure (difference -3·5 mm Hg, -7·0 to -0·0; p=0·0478), and 24 h diastolic blood pressure (difference -4·1 mm Hg, -7·8 to -0·4; p=0·0292). Evaluation of hourly changes in 24 h systolic blood pressure and diastolic blood pressure showed blood pressure reduction throughout 24 h for the renal denervation group. 3 month blood pressure reductions were not significantly different between groups. Medication adherence was about 60% and varied for individual patients throughout the study. No major adverse events were recorded in either group. Renal denervation in the main renal arteries and branches significantly reduced blood pressure compared with sham control with no major safety events. Incomplete medication adherence was common. Medtronic. Copyright © 2018 Elsevier Ltd. All rights reserved.

The FDA Unapproved Drugs Initiative: An Observational Study of the Consequences for Drug Prices and Shortages in the United States.

PubMed

Gupta, Ravi; Dhruva, Sanket S; Fox, Erin R; Ross, Joseph S

2017-10-01

Hundreds of drug products are currently marketed in the United States without approval from the FDA. The 2006 Unapproved Drugs Initiative (UDI) requires manufacturers to remove these drug products from the market or obtain FDA approval by demonstrating evidence of safety and efficacy. Once the FDA acts against an unapproved drug, fewer manufacturers remain in the market, potentially enabling drug price increases and greater susceptibility to drug shortages. There is a need for systematic study of the UDI's effect on prices and shortages of all targeted drugs. To examine the clinical evidence for approval and association with prices and shortages of previously unapproved prescription drugs after being addressed by the UDI. Previously unapproved prescription drugs that faced UDI regulatory action or with at least 1 product that received FDA approval through manufacturers' voluntary compliance with the UDI between 2006 and 2015 were identified. The clinical evidence was categorized as either newly conducted clinical trials or use of previously published literature and/or bioequivalence studies to demonstrate safety and efficacy. We determined the change in average wholesale price, presence of shortage, and duration of shortage for each drug during the 2 years before and after UDI regulatory action or approval through voluntary compliance. Between 2006 and 2015, 34 previously unapproved prescription drugs were addressed by the UDI. Nearly 90% of those with a drug product that received FDA approval were supported by literature reviews or bioequivalence studies, not new clinical trial evidence. Among the 26 drugs with available pricing data, average wholesale price during the 2 years before and after voluntary approval or UDI action increased by a median of 37% (interquartile range [IQR] = 23%-204%; P < 0.001). The number of drugs in shortage increased from 17 (50.0%) to 25 (73.5%) during the 2 years before and after, respectively (P = 0.046). The median shortage duration in the 2 years before and after voluntary approval or UDI action increased from 31 days (IQR = 0-339) to 217 days (IQR = 0-406; P = 0.053). The UDI was associated with higher drug prices and more frequent drug shortages when compared with the period before UDI action, while the approval process for these drugs did not necessarily require new clinical evidence to establish safety or efficacy. This project was not supported by any external grants or funds. Gupta was supported by the Yale University School of Medicine Office of Student Research at the time of this study. Dhruva is supported by the Department of Veterans Affairs as part of the Robert Wood Johnson Foundation Clinical Scholars program. Ross reports receiving research support through Yale University from Johnson and Johnson to develop methods of clinical trial data sharing; from Medtronic and the FDA to develop methods for postmarket surveillance of medical devices; from the FDA to establish the Yale-Mayo Clinic Center of Excellence in Regulatory Science and Innovation; from the Blue Cross Blue Shield Association to better understand medical technology evidence generation; from the Centers for Medicare & Medicaid Services to develop and maintain performance measures that are used for public reporting; and from the Laura and John Arnold Foundation to support the Collaboration on Research Integrity and Transparency at Yale. Fox reports travel support from Oklahoma Society of Health System Pharmacists, Premier Oncology Hematology Management Society, and SEHA-United Arab Emirates. Vizient provides some financial support to the University of Utah Drug Information Service to provide summaries of drug shortage information. Gupta and Ross were responsible for the conception and design of this work, drafted the manuscript, and conducted the statistical analysis. Gupta and Fox were responsible for acquisition of data. Ross provided supervision. All authors participated in the analysis and interpretation of the data and critically revised the manuscript for important intellectual content.

Functional morphology of the lower esophageal sphincter and crural diaphragm determined by three-dimensional high-resolution esophago-gastric junction pressure profile and CT imaging.

PubMed

Mittal, Ravinder K; Zifan, Ali; Kumar, Dushyant; Ledgerwood-Lee, Melissa; Ruppert, Erika; Ghahremani, Gary

2017-09-01

The smooth muscles of the lower esophageal sphincter (LES) and skeletal muscles of the crural diaphragm (CD) provide a closure/antireflux barrier mechanism at the esophago-gastric junction (EGJ). A number of questions in regard to the pressure profile of the LES and CD remain unclear, e.g., 1 ) Why is the LES pressure profile circumferentially asymmetric, 2 ) Is the crural diaphragm (CD) contraction also circumferentially asymmetric, and 3 ) Where is the LES and CD pressure profile located in the anatomy of the esophagus and stomach? The three-dimensional (3-D) high-resolution esophageal manometry (HRM) catheter can record a detailed profile of the EGJ pressure; however, it does not allow the determination of the circumferential orientation of individual pressure transducers in vivo. We used computed tomography (CT) scan imaging in combination with 3-D EGJ pressure recordings to determine the functional morphology of the LES and CD and its relationship to the EGJ anatomy. A 3-D-HRM catheter with 96 transducers (12 rings, 7.5 mm apart, located over 9-cm length of the catheter, with eight transducers in each ring, 45° apart (Medtronics), was used to record the EGJ pressure in 10 healthy subjects. A 0.5-mm diameter metal ball (BB) was taped to the catheter, adjacent to transducer 1 of the catheter. The EGJ was recorded under the following conditions: 1 ) end-expiration (LES pressure) before swallow, after swallow, and after edrophonium hydrochloride; and 2 ) peak inspiration (crural diaphragm contraction) for tidal inspiration and forced maximal inspiration. A CT scan was performed to localize the circumferential orientation of the BB. The CT scan imaging allowed the determination of the circumferential orientation of the LES and CD pressure profiles. The LES pressure under the three end-expiration conditions were different; however, the shape of the pressure profile was unique with the LES length longer toward the lesser curvature of the stomach as compared with the greater curvature. The pressure profile revealed circular and axial pressure asymmetry, with greatest pressure and shortest cranio-caudal length on the left (close to the angle of His). The CD contraction with tidal and forced inspiration increases pressure in the cranial half of the LES pressure profile, and it was placed horizontally across the recording. The CD, esophagus, and stomach were outlined in the CT scan images to construct a 3-D anatomy of the region; it revealed that the hiatus (CD) is placed obliquely across the esophagus; however, because of the bend of the esophagus to the left at the upper edge of the hiatus, the two were placed at right angle to each other, which resulted in a horizontal pressure profile of the CD on the LES. Our observations suggest a unique shape of the LES, CD, and the anatomical relationship between the two, which provides a possible explanation as to why the LES pressure shows circumferential and axial asymmetry. Our findings have implication for the length and circumferential orientation of myotomy incision required for the ablation of LES pressure in achalasia esophagus. NEW & NOTEWORTHY We used computed tomography scan imaging with three-dimensional esophago-gastric junction (EGJ) pressure recordings to determine functional morphology of the lower esophageal sphincter (LES) and crural diaphragm and its relationship to EGJ anatomy. The LES pressure profile was unique with the LES length longer and pressures lower toward the lesser curvature of the stomach, as compared with the greater curvature. Our findings have implications for the length and circumferential orientation of myotomy incision required for the ablation of LES pressure in the achalasia esophagus. Copyright © 2017 the American Physiological Society.

Uterine-sparing Laparoscopic Resection of Accessory Cavitated Uterine Masses.

PubMed

Peters, Ann; Rindos, Noah B; Guido, Richard S; Donnellan, Nicole M

2018-01-01

To demonstrate surgical techniques utilized during uterine-sparing laparoscopic resections of accessory cavitated uterine masses (ACUMs). ACUMs represent a rare uterine entity observed in premenopausal women suffering from dysmenorrhea and recurrent pelvic pain. The diagnosis is made when an isolated extra-cavitated uterine mass is resected from an otherwise normal appearing uterus with unremarkable endometrial lumen and adnexal structures. Pathologic confirmation requires an accessory cavity lined with endometrial epithelium (and corresponding glands and stroma) filled with chocolate-brown fluid. Adenomyosis must be absent. Although the origin of ACUMs is currently unknown, the most common presentation is a 2-4 cm lateral uterine wall mass at the level of the insertion of the round ligament. Hence it has been hypothesized that gubernaculum dysfunction may be responsible for duplication or persistence of paramesonephric tissue leading to ACUM formation as a new Müllerian anomaly. A stepwise surgical tutorial describing 2 laparoscopic ACUM resections using a narrated video (Canadian Task Force classification III). An academic tertiary care hospital. In this video, we present 2 patients who underwent uterine-sparing laparoscopic resections of their ACUM in order to preserve fertility (Case 1) or avoid the complications and surgical recovery time of a total laparoscopic hysterectomy (Case 2). Case 1 is a 19-year-old, gravida 0, para 0 woman with dysmenorrhea and recurrent pelvic pain who presented for multiple emergency room and outpatient evaluations. Transvaginal ultrasonography was unremarkable except for a 28×30×26mm left lateral uterine mass with peripheral vascular flow that was initially felt to be a leiomyoma or rudimentary uterine horn. MRI imaging, however, demonstrated this mass to be more consistent with an ACUM. This was based on the lack of communication between the lesion and the main uterine cavity exhibited by high T2 signal (compatible with endometrial tissue) surrounding low T2/high T1 signal in the dependent aspects (representing blood products). After counseling regarding treatment options including medical management with hormonal contraception, the patient elected for definitive fertility preserving laparoscopic resection. In contrast, case 2 is a 39-year-old, gravida 3, para 3 woman with a 2 month history or left lower quadrant pain following her last vaginal delivery. Transvaginal ultrasonography showed a 23×18×19mm cystic structure within the left uterine wall, which was confirmed to represent an ACUM on MRI. Although she had no desire for fertility preservation, the patient elected for surgical resection of the mass as opposed to a hysterectomy in order to minimize complications and recovery time. Laparoscopic resection of ACUMs in patients desiring uterine preservation. Laparoscopic resection of the ACUMs was performed utilizing 2 different techniques. In both cases, dilute vasopressin was injected with a modified butterfly or spinal needle along the uterine-ACUM serosal interphase to aid with hemostasis. In patients desiring to preserve fertility (case 1) monopolar energy is utilized to make an incision along the ACUM serosa to help facilitate dissection. ACUM enucleation is then commenced in a circumferential manner along the ACUM and uterine myometrial interphase utilizing bipolar energy. In contrast to leiomyomas where dissection advances along the pseudocapsule, ACUM have poorly delineated borders with disorganized muscular fibers making dissection particularly difficult. A variety of instruments can be utilized to help in the sequential circumferential dissection in addition to a bipolar device including a single-tooth tenaculum, myoma hook, suction device or fine-needle grasper. Ultimately, the ACUM is transected off its uterine-myometrial attachment and hemostasis is obtain before closing the uterine defect in at least 2 layers using a 2-0 barbed V-Loc (Medtronic, Minneapolis, MN). If fertility preservation is no longer desired, the dissection can greatly be expedited by performing a salpingectomy and skeletonizing the ACUM from the leaves of the broad ligament (case 2). A monopolar L-hook can then be used to transect the ACUM from the remaining uterine body. While difficult, these cases can be completed laparoscopically in approximately 2 hours with minimal blood loss. ACUMs are hypothesized to represent a previously under recognized Müllerian anomaly linked to gubernaculum dysfunction that occurs in premenopausal women with dysmenorrhea and chronic pelvic pain. Uterine and fertility sparing laparoscopic resection is possible but challenging due to poorly defined planes. Copyright © 2017 AAGL. Published by Elsevier Inc. All rights reserved.

Drug-eluting balloon angioplasty versus uncoated balloon angioplasty for peripheral arterial disease of the lower limbs.

PubMed

Kayssi, Ahmed; Al-Atassi, Talal; Oreopoulos, George; Roche-Nagle, Graham; Tan, Kong Teng; Rajan, Dheeraj K

2016-08-04

Atherosclerotic peripheral arterial disease (PAD) can lead to disabling ischemia and limb loss. Treatment modalities have included risk factor optimization through life-style modifications and medications, or operative approaches using both open and minimally invasive techniques, such as balloon angioplasty. Drug-eluting balloon (DEB) angioplasty has emerged as a promising alternative to uncoated balloon angioplasty for the treatment of this difficult disease process. By ballooning and coating the inside of atherosclerotic vessels with cytotoxic agents, such as paclitaxel, cellular mechanisms responsible for atherosclerosis and neointimal hyperplasia are inhibited and its devastating complications are prevented or postponed. DEBs are considerably more expensive than uncoated balloons, and their efficacy in improving patient outcomes is unclear. To assess the efficacy of drug-eluting balloons (DEBs) compared with uncoated, nonstenting balloon angioplasty in people with symptomatic lower-limb peripheral arterial disease (PAD). The Cochrane Vascular Trials Search Co-ordinator (TSC) searched the Specialised Register (last searched December 2015) and Cochrane Register of Studies (CRS) (2015, Issue 11). The TSC searched trial databases for details of ongoing and unpublished studies. We included all randomized controlled trials that compared DEBs with uncoated, nonstenting balloon angioplasty for intermittent claudication (IC) or critical limb ischemia (CLI). Two review authors (AK, TA) independently selected the appropriate trials and performed data extraction, assessment of trial quality, and data analysis. The senior review author (DKR) adjudicated any disagreements. Eleven trials that randomized 1838 participants met the study inclusion criteria. Seven of the trials included femoropopliteal arterial lesions, three included tibial arterial lesions, and one included both. The trials were carried out in Europe and in the USA and all used the taxane drug paclitaxel in the DEB arm. Nine of the 11 trials were industry-sponsored. Four companies manufactured the DEB devices (Bard, Bavaria Medizin, Biotronik, and Medtronic). The trials examined both anatomic and clinical endpoints. There was heterogeneity in the frequency of stent deployment and the type and duration of antiplatelet therapy between trials. Using GRADE assessment criteria, the quality of the evidence presented was moderate for the outcomes of target lesion revascularization and change in Rutherford category, and high for amputation, primary vessel patency, binary restenosis, death, and change in ankle-brachial index (ABI). Most participants were followed up for 12 months, but one trial reported outcomes at five years.There were better outcomes for DEBs for up to two years in primary vessel patency (odds ratio (OR) 1.47, 95% confidence interval (CI) 0.22 to 9.57 at six months; OR 1.92, 95% CI 1.45 to 2.56 at 12 months; OR 3.51, 95% CI 2.26 to 5.46 at two years) and at six months and two years for late lumen loss (mean difference (MD) -0.64 mm, 95% CI -1.00 to -0.28 at six months; MD -0.80 mm, 95% CI -1.44 to -0.16 at two years). DEB were also superior to uncoated balloon angioplasty for up to five years in target lesion revascularization (OR 0.28, 95% CI 0.17 to 0.47 at six months; OR 0.40, 95% CI 0.31 to 0.51 at 12 months; OR 0.28, 95% CI 0.18 to 0.44 at two years; OR 0.21, 95% CI 0.09 to 0.51 at five years) and binary restenosis rate (OR 0.44, 95% CI 0.29 to 0.67 at six months; OR 0.38, 95% CI 0.15 to 0.98 at 12 months; OR 0.26, 95% CI 0.10 to 0.66 at two years; OR 0.12, 95% CI 0.05 to 0.30 at five years). There was no significant difference between DEB and uncoated angioplasty in amputation, death, change in ABI, change in Rutherford category and quality of life (QoL) scores, or functional walking ability, although none of the trials were powered to detect a significant difference in these clinical endpoints. We carried out two subgroup analyses to examine outcomes in femoropopliteal and tibial interventions as well as in people with CLI (4 or greater Rutherford class), and showed no advantage for DEBs in tibial vessels at six and 12 months compared with uncoated balloon angioplasty. There was also no advantage for DEBs in CLI compared with uncoated balloon angioplasty at 12 months. Based on a meta-analysis of 11 trials with 1838 participants, there is evidence of an advantage for DEBs compared with uncoated balloon angioplasty in several anatomic endpoints such as primary vessel patency (high-quality evidence), binary restenosis rate (moderate-quality evidence), and target lesion revascularization (low-quality evidence) for up to 12 months. Conversely, there is no evidence of an advantage for DEBs in clinical endpoints such as amputation, death, or change in ABI, or change in Rutherford category during 12 months' follow-up. Well-designed randomized trials with long-term follow-up are needed to compare DEBs with uncoated balloon angioplasties adequately for both anatomic and clinical study endpoints before the widespread use of this expensive technology can be justified.

WE-DE-207A-04: Advances in Radiological Neuro-Endovascular Interventional Imaging

DOE Office of Scientific and Technical Information (OSTI.GOV)

Rudin, S.

1. Parallels in the evolution of x-ray angiographic systems and devices used for minimally invasive endovascular therapy Charles Strother - DSA, invented by Dr. Charles Mistretta at UW-Madison, was the technology which enabled the development of minimally invasive endovascular procedures. As DSA became widely available and the potential benefits for accessing the cerebral vasculature from an endovascular approach began to be apparent, industry began efforts to develop tools for use in these procedures. Along with development of catheters, embolic materials, pushable coils and the GDC coils there was simultaneous development and improvement of 2D DSA image quality and the introductionmore » of 3D DSA. Together, these advances resulted in an enormous expansion in the scope and numbers of minimally invasive endovascular procedures. The introduction of flat detectors for c-arm angiographic systems in 2002 provided the possibility of the angiographic suite becoming not just a location for vascular imaging where physiological assessments might also be performed. Over the last decade algorithmic and hardware advances have been sufficient to now realize this potential in clinical practice. The selection of patients for endovascular treatments is enhanced by this dual capability. Along with these advances has been a steady reduction in the radiation exposure required so that today, vascular and soft tissue images may be obtained with equal or in many cases less radiation exposure than is the case for comparable images obtained with multi-detector CT. Learning Objectives: To understand the full capabilities of today’s angiographic suite To understand how c-arm cone beam CT soft tissue imaging can be used for assessments of devices, blood flow and perfusion. Advances in real-time x-ray neuro-endovascular image guidance Stephen Rudin - Reacting to the demands on real-time image guidance for ever finer neurovascular interventions, great improvements in imaging chains are being pursued. For the highest spatial and temporal resolution, x-ray guidance with fluoroscopy and angiography although dominant are still being vastly improved. New detectors such as the Micro-Angiographic Fluoroscope (MAF) and x-ray source designs that enable higher outputs while maintaining small focal spots will be highlighted along with new methods for minimizing the radiation dose to patients. Additionally, new platforms for training and device testing that include patient-specific 3D printed vascular phantoms and new metrics such as generalized relative object detectability for objectively inter-comparing systems will be discussed. This will improve the opportunity for better evaluation of these technological advances which should contribute to the safety and efficacy of image guided minimally invasive neuro-endovascular procedures. Learning Objectives: To understand the operation of new x-ray imaging chain components such as detectors and sources To be informed about the latest testing methods, with 3D printed vascular phantoms, and new evaluation metrics for advanced imaging in x-ray image guided neurovascular interventions Advances in cone beam CT anatomical and functional imaging in angio-suite to enable one-stop-shop stroke imaging workflow Guang-Hong Chen - The introduction of flat-panel detector based cone-beam CT in clinical angiographic imaging systems enabled treating physicians to obtain three-dimensional anatomic roadmaps for bony structure, soft brain tissue, and vasculatures for treatment planning and efficacy checking after the procedures. However, much improvement is needed to reduce image artifacts, reduce radiation dose, and add potential functional imaging capability to provide four-dimensional dynamic information of vasculature and brain perfusion. In this presentation, some of the new techniques developed to address radiation dose issues, image artifact reduction and brain perfusion using C-arm cone-beam CT imaging system will be introduced for the audience. Learning Objectives: To understand the clinical need of one-stop-shop stroke imaging workflow To understand to technical challenges in cone beam CT perfusion To understand the potential technical solutions to enable one-stop-shop imaging workflow Recent advances in devices used in neuro--interventions Mattew Gounis - Over the past two decades, there has been explosive development of medical devices that have revolutionized the endovascular treatment of cerebrovascular diseases. There is now Level 1, Class A evidence that intra-arterial, mechanical thrombectomy in acute ischemic stroke is superior to medical management; and similarly that minimally invasive, endovascular repair of ruptured brain aneurysms is superior to surgical treatment. Stent-retrievers are now standard of care for emergent large vessel occlusions causing a stroke, with a number of patients need to treat for good clinical outcomes as low as 4. Recent technologies such as flow diverters and disrupters, intracranial self-expanding stents, flexible large bore catheters that can reach vessels beyond the circle of Willis, stent-retrievers, and super-compliant balloons are the result of successful miniaturization of design features and novel manufacturing technologies capable of building these devices. This is a rapidly evolving field, and the device technology enabling such advancements will be reviewed. Importantly, image-guidance technology has not kept pace in neurointervention and the ability to adequately characterize these devices in vivo remains a significant opportunity. Learning Objectives: A survey of devices used in neurointerventions, their materials and essential design characteristics Funding support received from NIH and DOD; Funding support received from GE Healthcare; Funding support received from Siemens AX; Patent royalties received from GE Healthcare; G. Chen, Funding received from NIH; funding received from DOD; funding received from GE Healthcare; funding received from Siemens AX.; M. Gounis, consultant for Codman Neurovascular and Stryker Neurovascular; Holds stock in InNeuroCo Inc, research grants: NIH, Medtronic Neurovascular, Microvention/Terumo, Cerevasc LLC, Gentuity, Codman Neurovascular, Philips Healthcare, Stryker Neurovascular, Tay Sachs Foundation, and InNeuroCo Inc.; S. Rudin, Supported in part by NIH Grant R01EB002873 and the Toshiba Medical System Corp.« less

WE-DE-207A-01: Parallels in the Evolution of X-Ray Angiographic Systems and Devices Used for Minimally Invasive Endovascular Therapy

DOE Office of Scientific and Technical Information (OSTI.GOV)

Strother, C.

1. Parallels in the evolution of x-ray angiographic systems and devices used for minimally invasive endovascular therapy Charles Strother - DSA, invented by Dr. Charles Mistretta at UW-Madison, was the technology which enabled the development of minimally invasive endovascular procedures. As DSA became widely available and the potential benefits for accessing the cerebral vasculature from an endovascular approach began to be apparent, industry began efforts to develop tools for use in these procedures. Along with development of catheters, embolic materials, pushable coils and the GDC coils there was simultaneous development and improvement of 2D DSA image quality and the introductionmore » of 3D DSA. Together, these advances resulted in an enormous expansion in the scope and numbers of minimally invasive endovascular procedures. The introduction of flat detectors for c-arm angiographic systems in 2002 provided the possibility of the angiographic suite becoming not just a location for vascular imaging where physiological assessments might also be performed. Over the last decade algorithmic and hardware advances have been sufficient to now realize this potential in clinical practice. The selection of patients for endovascular treatments is enhanced by this dual capability. Along with these advances has been a steady reduction in the radiation exposure required so that today, vascular and soft tissue images may be obtained with equal or in many cases less radiation exposure than is the case for comparable images obtained with multi-detector CT. Learning Objectives: To understand the full capabilities of today’s angiographic suite To understand how c-arm cone beam CT soft tissue imaging can be used for assessments of devices, blood flow and perfusion. Advances in real-time x-ray neuro-endovascular image guidance Stephen Rudin - Reacting to the demands on real-time image guidance for ever finer neurovascular interventions, great improvements in imaging chains are being pursued. For the highest spatial and temporal resolution, x-ray guidance with fluoroscopy and angiography although dominant are still being vastly improved. New detectors such as the Micro-Angiographic Fluoroscope (MAF) and x-ray source designs that enable higher outputs while maintaining small focal spots will be highlighted along with new methods for minimizing the radiation dose to patients. Additionally, new platforms for training and device testing that include patient-specific 3D printed vascular phantoms and new metrics such as generalized relative object detectability for objectively inter-comparing systems will be discussed. This will improve the opportunity for better evaluation of these technological advances which should contribute to the safety and efficacy of image guided minimally invasive neuro-endovascular procedures. Learning Objectives: To understand the operation of new x-ray imaging chain components such as detectors and sources To be informed about the latest testing methods, with 3D printed vascular phantoms, and new evaluation metrics for advanced imaging in x-ray image guided neurovascular interventions Advances in cone beam CT anatomical and functional imaging in angio-suite to enable one-stop-shop stroke imaging workflow Guang-Hong Chen - The introduction of flat-panel detector based cone-beam CT in clinical angiographic imaging systems enabled treating physicians to obtain three-dimensional anatomic roadmaps for bony structure, soft brain tissue, and vasculatures for treatment planning and efficacy checking after the procedures. However, much improvement is needed to reduce image artifacts, reduce radiation dose, and add potential functional imaging capability to provide four-dimensional dynamic information of vasculature and brain perfusion. In this presentation, some of the new techniques developed to address radiation dose issues, image artifact reduction and brain perfusion using C-arm cone-beam CT imaging system will be introduced for the audience. Learning Objectives: To understand the clinical need of one-stop-shop stroke imaging workflow To understand to technical challenges in cone beam CT perfusion To understand the potential technical solutions to enable one-stop-shop imaging workflow Recent advances in devices used in neuro--interventions Mattew Gounis - Over the past two decades, there has been explosive development of medical devices that have revolutionized the endovascular treatment of cerebrovascular diseases. There is now Level 1, Class A evidence that intra-arterial, mechanical thrombectomy in acute ischemic stroke is superior to medical management; and similarly that minimally invasive, endovascular repair of ruptured brain aneurysms is superior to surgical treatment. Stent-retrievers are now standard of care for emergent large vessel occlusions causing a stroke, with a number of patients need to treat for good clinical outcomes as low as 4. Recent technologies such as flow diverters and disrupters, intracranial self-expanding stents, flexible large bore catheters that can reach vessels beyond the circle of Willis, stent-retrievers, and super-compliant balloons are the result of successful miniaturization of design features and novel manufacturing technologies capable of building these devices. This is a rapidly evolving field, and the device technology enabling such advancements will be reviewed. Importantly, image-guidance technology has not kept pace in neurointervention and the ability to adequately characterize these devices in vivo remains a significant opportunity. Learning Objectives: A survey of devices used in neurointerventions, their materials and essential design characteristics Funding support received from NIH and DOD; Funding support received from GE Healthcare; Funding support received from Siemens AX; Patent royalties received from GE Healthcare; G. Chen, Funding received from NIH; funding received from DOD; funding received from GE Healthcare; funding received from Siemens AX.; M. Gounis, consultant for Codman Neurovascular and Stryker Neurovascular; Holds stock in InNeuroCo Inc, research grants: NIH, Medtronic Neurovascular, Microvention/Terumo, Cerevasc LLC, Gentuity, Codman Neurovascular, Philips Healthcare, Stryker Neurovascular, Tay Sachs Foundation, and InNeuroCo Inc.; S. Rudin, Supported in part by NIH Grant R01EB002873 and the Toshiba Medical System Corp.« less

WE-DE-207A-03: Recent Advances in Devices Used in Neuro--Interventions

DOE Office of Scientific and Technical Information (OSTI.GOV)

Gounis, M.

1. Parallels in the evolution of x-ray angiographic systems and devices used for minimally invasive endovascular therapy Charles Strother - DSA, invented by Dr. Charles Mistretta at UW-Madison, was the technology which enabled the development of minimally invasive endovascular procedures. As DSA became widely available and the potential benefits for accessing the cerebral vasculature from an endovascular approach began to be apparent, industry began efforts to develop tools for use in these procedures. Along with development of catheters, embolic materials, pushable coils and the GDC coils there was simultaneous development and improvement of 2D DSA image quality and the introductionmore » of 3D DSA. Together, these advances resulted in an enormous expansion in the scope and numbers of minimally invasive endovascular procedures. The introduction of flat detectors for c-arm angiographic systems in 2002 provided the possibility of the angiographic suite becoming not just a location for vascular imaging where physiological assessments might also be performed. Over the last decade algorithmic and hardware advances have been sufficient to now realize this potential in clinical practice. The selection of patients for endovascular treatments is enhanced by this dual capability. Along with these advances has been a steady reduction in the radiation exposure required so that today, vascular and soft tissue images may be obtained with equal or in many cases less radiation exposure than is the case for comparable images obtained with multi-detector CT. Learning Objectives: To understand the full capabilities of today’s angiographic suite To understand how c-arm cone beam CT soft tissue imaging can be used for assessments of devices, blood flow and perfusion. Advances in real-time x-ray neuro-endovascular image guidance Stephen Rudin - Reacting to the demands on real-time image guidance for ever finer neurovascular interventions, great improvements in imaging chains are being pursued. For the highest spatial and temporal resolution, x-ray guidance with fluoroscopy and angiography although dominant are still being vastly improved. New detectors such as the Micro-Angiographic Fluoroscope (MAF) and x-ray source designs that enable higher outputs while maintaining small focal spots will be highlighted along with new methods for minimizing the radiation dose to patients. Additionally, new platforms for training and device testing that include patient-specific 3D printed vascular phantoms and new metrics such as generalized relative object detectability for objectively inter-comparing systems will be discussed. This will improve the opportunity for better evaluation of these technological advances which should contribute to the safety and efficacy of image guided minimally invasive neuro-endovascular procedures. Learning Objectives: To understand the operation of new x-ray imaging chain components such as detectors and sources To be informed about the latest testing methods, with 3D printed vascular phantoms, and new evaluation metrics for advanced imaging in x-ray image guided neurovascular interventions Advances in cone beam CT anatomical and functional imaging in angio-suite to enable one-stop-shop stroke imaging workflow Guang-Hong Chen - The introduction of flat-panel detector based cone-beam CT in clinical angiographic imaging systems enabled treating physicians to obtain three-dimensional anatomic roadmaps for bony structure, soft brain tissue, and vasculatures for treatment planning and efficacy checking after the procedures. However, much improvement is needed to reduce image artifacts, reduce radiation dose, and add potential functional imaging capability to provide four-dimensional dynamic information of vasculature and brain perfusion. In this presentation, some of the new techniques developed to address radiation dose issues, image artifact reduction and brain perfusion using C-arm cone-beam CT imaging system will be introduced for the audience. Learning Objectives: To understand the clinical need of one-stop-shop stroke imaging workflow To understand to technical challenges in cone beam CT perfusion To understand the potential technical solutions to enable one-stop-shop imaging workflow Recent advances in devices used in neuro--interventions Mattew Gounis - Over the past two decades, there has been explosive development of medical devices that have revolutionized the endovascular treatment of cerebrovascular diseases. There is now Level 1, Class A evidence that intra-arterial, mechanical thrombectomy in acute ischemic stroke is superior to medical management; and similarly that minimally invasive, endovascular repair of ruptured brain aneurysms is superior to surgical treatment. Stent-retrievers are now standard of care for emergent large vessel occlusions causing a stroke, with a number of patients need to treat for good clinical outcomes as low as 4. Recent technologies such as flow diverters and disrupters, intracranial self-expanding stents, flexible large bore catheters that can reach vessels beyond the circle of Willis, stent-retrievers, and super-compliant balloons are the result of successful miniaturization of design features and novel manufacturing technologies capable of building these devices. This is a rapidly evolving field, and the device technology enabling such advancements will be reviewed. Importantly, image-guidance technology has not kept pace in neurointervention and the ability to adequately characterize these devices in vivo remains a significant opportunity. Learning Objectives: A survey of devices used in neurointerventions, their materials and essential design characteristics Funding support received from NIH and DOD; Funding support received from GE Healthcare; Funding support received from Siemens AX; Patent royalties received from GE Healthcare; G. Chen, Funding received from NIH; funding received from DOD; funding received from GE Healthcare; funding received from Siemens AX.; M. Gounis, consultant for Codman Neurovascular and Stryker Neurovascular; Holds stock in InNeuroCo Inc, research grants: NIH, Medtronic Neurovascular, Microvention/Terumo, Cerevasc LLC, Gentuity, Codman Neurovascular, Philips Healthcare, Stryker Neurovascular, Tay Sachs Foundation, and InNeuroCo Inc.; S. Rudin, Supported in part by NIH Grant R01EB002873 and the Toshiba Medical System Corp.« less

WE-DE-207A-00: Advances in Image-Guided Neurointerventions-Clinical Pull and Technology Push

DOE Office of Scientific and Technical Information (OSTI.GOV)

NONE

1. Parallels in the evolution of x-ray angiographic systems and devices used for minimally invasive endovascular therapy Charles Strother - DSA, invented by Dr. Charles Mistretta at UW-Madison, was the technology which enabled the development of minimally invasive endovascular procedures. As DSA became widely available and the potential benefits for accessing the cerebral vasculature from an endovascular approach began to be apparent, industry began efforts to develop tools for use in these procedures. Along with development of catheters, embolic materials, pushable coils and the GDC coils there was simultaneous development and improvement of 2D DSA image quality and the introductionmore » of 3D DSA. Together, these advances resulted in an enormous expansion in the scope and numbers of minimally invasive endovascular procedures. The introduction of flat detectors for c-arm angiographic systems in 2002 provided the possibility of the angiographic suite becoming not just a location for vascular imaging where physiological assessments might also be performed. Over the last decade algorithmic and hardware advances have been sufficient to now realize this potential in clinical practice. The selection of patients for endovascular treatments is enhanced by this dual capability. Along with these advances has been a steady reduction in the radiation exposure required so that today, vascular and soft tissue images may be obtained with equal or in many cases less radiation exposure than is the case for comparable images obtained with multi-detector CT. Learning Objectives: To understand the full capabilities of today’s angiographic suite To understand how c-arm cone beam CT soft tissue imaging can be used for assessments of devices, blood flow and perfusion. Advances in real-time x-ray neuro-endovascular image guidance Stephen Rudin - Reacting to the demands on real-time image guidance for ever finer neurovascular interventions, great improvements in imaging chains are being pursued. For the highest spatial and temporal resolution, x-ray guidance with fluoroscopy and angiography although dominant are still being vastly improved. New detectors such as the Micro-Angiographic Fluoroscope (MAF) and x-ray source designs that enable higher outputs while maintaining small focal spots will be highlighted along with new methods for minimizing the radiation dose to patients. Additionally, new platforms for training and device testing that include patient-specific 3D printed vascular phantoms and new metrics such as generalized relative object detectability for objectively inter-comparing systems will be discussed. This will improve the opportunity for better evaluation of these technological advances which should contribute to the safety and efficacy of image guided minimally invasive neuro-endovascular procedures. Learning Objectives: To understand the operation of new x-ray imaging chain components such as detectors and sources To be informed about the latest testing methods, with 3D printed vascular phantoms, and new evaluation metrics for advanced imaging in x-ray image guided neurovascular interventions Advances in cone beam CT anatomical and functional imaging in angio-suite to enable one-stop-shop stroke imaging workflow Guang-Hong Chen - The introduction of flat-panel detector based cone-beam CT in clinical angiographic imaging systems enabled treating physicians to obtain three-dimensional anatomic roadmaps for bony structure, soft brain tissue, and vasculatures for treatment planning and efficacy checking after the procedures. However, much improvement is needed to reduce image artifacts, reduce radiation dose, and add potential functional imaging capability to provide four-dimensional dynamic information of vasculature and brain perfusion. In this presentation, some of the new techniques developed to address radiation dose issues, image artifact reduction and brain perfusion using C-arm cone-beam CT imaging system will be introduced for the audience. Learning Objectives: To understand the clinical need of one-stop-shop stroke imaging workflow To understand to technical challenges in cone beam CT perfusion To understand the potential technical solutions to enable one-stop-shop imaging workflow Recent advances in devices used in neuro--interventions Mattew Gounis - Over the past two decades, there has been explosive development of medical devices that have revolutionized the endovascular treatment of cerebrovascular diseases. There is now Level 1, Class A evidence that intra-arterial, mechanical thrombectomy in acute ischemic stroke is superior to medical management; and similarly that minimally invasive, endovascular repair of ruptured brain aneurysms is superior to surgical treatment. Stent-retrievers are now standard of care for emergent large vessel occlusions causing a stroke, with a number of patients need to treat for good clinical outcomes as low as 4. Recent technologies such as flow diverters and disrupters, intracranial self-expanding stents, flexible large bore catheters that can reach vessels beyond the circle of Willis, stent-retrievers, and super-compliant balloons are the result of successful miniaturization of design features and novel manufacturing technologies capable of building these devices. This is a rapidly evolving field, and the device technology enabling such advancements will be reviewed. Importantly, image-guidance technology has not kept pace in neurointervention and the ability to adequately characterize these devices in vivo remains a significant opportunity. Learning Objectives: A survey of devices used in neurointerventions, their materials and essential design characteristics Funding support received from NIH and DOD; Funding support received from GE Healthcare; Funding support received from Siemens AX; Patent royalties received from GE Healthcare; G. Chen, Funding received from NIH; funding received from DOD; funding received from GE Healthcare; funding received from Siemens AX.; M. Gounis, consultant for Codman Neurovascular and Stryker Neurovascular; Holds stock in InNeuroCo Inc, research grants: NIH, Medtronic Neurovascular, Microvention/Terumo, Cerevasc LLC, Gentuity, Codman Neurovascular, Philips Healthcare, Stryker Neurovascular, Tay Sachs Foundation, and InNeuroCo Inc.; S. Rudin, Supported in part by NIH Grant R01EB002873 and the Toshiba Medical System Corp.« less

WE-DE-207A-02: Advances in Cone Beam CT Anatomical and Functional Imaging in Angio-Suite to Enable One-Stop-Shop Stroke Imaging Workflow

DOE Office of Scientific and Technical Information (OSTI.GOV)

Chen, G.

1. Parallels in the evolution of x-ray angiographic systems and devices used for minimally invasive endovascular therapy Charles Strother - DSA, invented by Dr. Charles Mistretta at UW-Madison, was the technology which enabled the development of minimally invasive endovascular procedures. As DSA became widely available and the potential benefits for accessing the cerebral vasculature from an endovascular approach began to be apparent, industry began efforts to develop tools for use in these procedures. Along with development of catheters, embolic materials, pushable coils and the GDC coils there was simultaneous development and improvement of 2D DSA image quality and the introductionmore » of 3D DSA. Together, these advances resulted in an enormous expansion in the scope and numbers of minimally invasive endovascular procedures. The introduction of flat detectors for c-arm angiographic systems in 2002 provided the possibility of the angiographic suite becoming not just a location for vascular imaging where physiological assessments might also be performed. Over the last decade algorithmic and hardware advances have been sufficient to now realize this potential in clinical practice. The selection of patients for endovascular treatments is enhanced by this dual capability. Along with these advances has been a steady reduction in the radiation exposure required so that today, vascular and soft tissue images may be obtained with equal or in many cases less radiation exposure than is the case for comparable images obtained with multi-detector CT. Learning Objectives: To understand the full capabilities of today’s angiographic suite To understand how c-arm cone beam CT soft tissue imaging can be used for assessments of devices, blood flow and perfusion. Advances in real-time x-ray neuro-endovascular image guidance Stephen Rudin - Reacting to the demands on real-time image guidance for ever finer neurovascular interventions, great improvements in imaging chains are being pursued. For the highest spatial and temporal resolution, x-ray guidance with fluoroscopy and angiography although dominant are still being vastly improved. New detectors such as the Micro-Angiographic Fluoroscope (MAF) and x-ray source designs that enable higher outputs while maintaining small focal spots will be highlighted along with new methods for minimizing the radiation dose to patients. Additionally, new platforms for training and device testing that include patient-specific 3D printed vascular phantoms and new metrics such as generalized relative object detectability for objectively inter-comparing systems will be discussed. This will improve the opportunity for better evaluation of these technological advances which should contribute to the safety and efficacy of image guided minimally invasive neuro-endovascular procedures. Learning Objectives: To understand the operation of new x-ray imaging chain components such as detectors and sources To be informed about the latest testing methods, with 3D printed vascular phantoms, and new evaluation metrics for advanced imaging in x-ray image guided neurovascular interventions Advances in cone beam CT anatomical and functional imaging in angio-suite to enable one-stop-shop stroke imaging workflow Guang-Hong Chen - The introduction of flat-panel detector based cone-beam CT in clinical angiographic imaging systems enabled treating physicians to obtain three-dimensional anatomic roadmaps for bony structure, soft brain tissue, and vasculatures for treatment planning and efficacy checking after the procedures. However, much improvement is needed to reduce image artifacts, reduce radiation dose, and add potential functional imaging capability to provide four-dimensional dynamic information of vasculature and brain perfusion. In this presentation, some of the new techniques developed to address radiation dose issues, image artifact reduction and brain perfusion using C-arm cone-beam CT imaging system will be introduced for the audience. Learning Objectives: To understand the clinical need of one-stop-shop stroke imaging workflow To understand to technical challenges in cone beam CT perfusion To understand the potential technical solutions to enable one-stop-shop imaging workflow Recent advances in devices used in neuro--interventions Mattew Gounis - Over the past two decades, there has been explosive development of medical devices that have revolutionized the endovascular treatment of cerebrovascular diseases. There is now Level 1, Class A evidence that intra-arterial, mechanical thrombectomy in acute ischemic stroke is superior to medical management; and similarly that minimally invasive, endovascular repair of ruptured brain aneurysms is superior to surgical treatment. Stent-retrievers are now standard of care for emergent large vessel occlusions causing a stroke, with a number of patients need to treat for good clinical outcomes as low as 4. Recent technologies such as flow diverters and disrupters, intracranial self-expanding stents, flexible large bore catheters that can reach vessels beyond the circle of Willis, stent-retrievers, and super-compliant balloons are the result of successful miniaturization of design features and novel manufacturing technologies capable of building these devices. This is a rapidly evolving field, and the device technology enabling such advancements will be reviewed. Importantly, image-guidance technology has not kept pace in neurointervention and the ability to adequately characterize these devices in vivo remains a significant opportunity. Learning Objectives: A survey of devices used in neurointerventions, their materials and essential design characteristics Funding support received from NIH and DOD; Funding support received from GE Healthcare; Funding support received from Siemens AX; Patent royalties received from GE Healthcare; G. Chen, Funding received from NIH; funding received from DOD; funding received from GE Healthcare; funding received from Siemens AX.; M. Gounis, consultant for Codman Neurovascular and Stryker Neurovascular; Holds stock in InNeuroCo Inc, research grants: NIH, Medtronic Neurovascular, Microvention/Terumo, Cerevasc LLC, Gentuity, Codman Neurovascular, Philips Healthcare, Stryker Neurovascular, Tay Sachs Foundation, and InNeuroCo Inc.; S. Rudin, Supported in part by NIH Grant R01EB002873 and the Toshiba Medical System Corp.« less

CME/CNE Article: A Framework of Care in Multiple Sclerosis, Part 1: Updated Disease Classification and Disease-Modifying Therapy Use in Specific Circumstances.

PubMed

Newsome, Scott D; Aliotta, Philip J; Bainbridge, Jacquelyn; Bennett, Susan E; Cutter, Gary; Fenton, Kaylan; Lublin, Fred; Northrop, Dorothy; Rintell, David; Walker, Bryan D; Weigel, Megan; Zackowski, Kathleen; Jones, David E

2016-01-01

Activity Available Online: To access the article, post-test, and evaluation online, go to http://www.cmscscholar.org. The target audience for this activity is physicians, physician assistants, nursing professionals, and other health-care providers involved in the management of patients with multiple sclerosis (MS). Apply new information about MS to a comprehensive individualized treatment plan for patients with MSIntegrate the team approach into long-term planning in order to optimize rehabilitation care of patients with MSAccreditation Statement: This activity has been planned and implemented in accordance with the accreditation requirements and policies of the Accreditation Council for Continuing Medical Education (ACCME) through the joint providership of the Consortium of Multiple Sclerosis Centers (CMSC), Nurse Practitioner Alternatives (NPA), and Delaware Media Group. The CMSC is accredited by the ACCME to provide continuing medical education for physicians. The CMSC designates this journal-based CME activity for a maximum of 1.0 AMA PRA Category 1 Credit(s) ™. Physicians should claim only the credit commensurate with the extent of their participation in the activity. Nurse Practitioner Alternatives (NPA) is accredited as a provider of continuing nursing education by the American Nurses Credentialing Center's Commission on Accreditation. NPA designates this enduring material for 1.0 Continuing Nursing Education credit. Laurie Scudder, DNP, NP, has served as Nurse Planner for this activity. She has disclosed no relevant financial relationships. Disclosures: Francois Bethoux, MD , Editor in Chief of the International Journal of MS Care (IJMSC), has served as Physician Planner for this activity. He has received royalties from Springer Publishing and has received intellectual property rights from Biogen. Laurie Scudder, DNP, NP , has served as Nurse Planner for this activity. She has disclosed no relevant financial relationships. Scott D. Newsome, DO, MSCS (author), has served on scientific advisory boards for Biogen, Genentech, Novartis, and Genzyme, and has performed contracted research (institution received funds) for Biogen, Genentech, and Novartis. Philip J. Aliotta, MD, MSHA, CHCQM, FACS (author), has served on speakers' bureaus for Astellas Pharma, Actavis, Augmenix, and Allergan and has performed contracted research for Allergan. Jacquelyn Bainbridge, PharmD (author), has disclosed no relevant financial relationships. Susan E. Bennett, PT, DPT, EdD, NCS, MSCS (author), has served on speakers' bureaus for Acorda Therapeutics, Biogen, and Medtronic; has received consulting fees from and performed contracted research for Acorda Therapeutics; and is chair of the Clinical Events Committee at Innovative Technologies. Gary Cutter, PhD (author), has participated on Data and Safety Monitoring Committees for AMO Pharma, Apotek, Gilead Pharmaceuticals, Horizon Pharmaceuticals, Modigenetech/Prolor, Merck, Merck/Pfizer, Opko Biologics, Neuren, Sanofi-Aventis, Reata Pharmaceuticals, Receptos/Celgene, Teva Pharmaceuticals, NHLBI (Protocol Review Committee), and NICHD (OPRU Oversight Committee); has received consulting fees from and/or served on speakers' bureaus and scientific advisory boards for Cerespir, Genzyme, Genentech, Innate Therapeutics, Janssen Pharmaceuticals, Klein-Buendel Incorporated, MedImmune, Medday, Nivalis, Novartis, Opexa Therapeutics, Roche, Savara, Somahlution, Teva Pharmaceuticals, Transparency Life Sciences, and TG Therapeutics; and is President of Pythagoras, Inc., a private consulting company located in Birmingham, AL. Kaylan Fenton, CRNP, APNP, MSCN (author), has disclosed no relevant financial relationships. Fred Lublin, MD (author), has received consulting fees/fees for non-CME/CE activities from Bayer HealthCare Pharmaceuticals, Biogen, EMD Serono, Novartis, Teva Neuroscience, Actelion, Sanofi/Genzyme, Acorda, Questcor/Mallinckrodt, Roche/Genentech, MedImmune, Osmotica, Xenoport, Receptos/Celgene, Forward Pharma, Akros, TG Therapeutics, AbbVie, Toyama, Amgen, Medday, Atara Biotherapeutics, Polypharma, Pfizer, Johnson & Johnson, Revalesio, Coronado Bioscience, and Bristol-Myers Squibb; has served on speakers' bureaus for Genentech/Roche and Genzyme/Sanofi; has performed contracted research for Acorda, Biogen, Novartis, Teva Neuroscience, Genzyme, Xenoport, and Receptos; is the co-chief editor of Multiple Sclerosis and Related Disorders ; and has an ownership interest in Cognition Pharmaceuticals. Dorothy Northrop, MSW, ACSW (author), has disclosed no relevant financial relationships. David Rintell, EdD (author), has received consulting fees from Novartis and has served as a patient education speaker for Teva Neuroscience. He started as a salaried employee of Sanofi Genzyme in November 2015. Dr. Rintell's work on this project was completed before he became a salaried employee of Sanofi Genzyme. Bryan D. Walker, MHS, PA-C (author), has served on scientific advisory boards for EMD Serono and Sanofi Genzyme and owns stock in Biogen. Megan Weigel, DNP, ARNP-C, MSCN (author), has received consulting fees from Mallinckrodt, Genzyme, and Genentech, and has served on speakers' bureaus for Bayer Corp, Acorda Therapeutics, Teva Neuroscience, Biogen, Mallinckrodt, Genzyme, Novartis, and Pfizer. Kathleen Zackowski, PhD, OTR, MSCS (author), has performed contracted research for Acorda Therapeutics. David E. Jones, MD (author), has received consulting fees from Biogen and Novartis, and has performed contracted research for Biogen. One anonymous peer reviewer for the IJMSC has performed contracted research (institution received funds) for Novartis, Chugai, and Biogen. Another reviewer has received consulting fees and served on speakers' bureaus for Biogen, Sanofi Genzyme, Genentech, EMD Serono, and Novartis. The third reviewer has disclosed no relevant financial relationships. Lori Saslow, MS (medical writer), has disclosed no relevant financial relationships. The staff at the IJMSC, CMSC, NPA, and Delaware Media Group who are in a position to influence content have disclosed no relevant financial relationships. Note: Disclosures listed for authors are those applicable at the time of their work on this project and within 12 months previously. Financial relationships for some authors may have changed in the interval between the time of their work on this project and publication of the article. Funding/Support: Funding for the Framework of Care consensus conference was provided by the Consortium of Multiple Sclerosis Centers, Mallinckrodt Pharmaceuticals, and Mylan Pharmaceuticals. Method of Participation: Release Date: December 1, 2016 Valid for Credit Through: December 1, 2017 In order to receive CME/CNE credit, participants must: Review the CME/CNE information, including learning objectives and author disclosures.Study the educational content.Complete the post-test and evaluation, which are available at http://www.cmscscholar.org. Statements of Credit are awarded upon successful completion of the post-test with a passing score of >70% and the evaluation. There is no fee to participate in this activity. Disclosure of Unlabeled Use: This CME/CNE activity may contain discussion of published and/or investigational uses of agents that are not approved by the FDA. CMSC, NPA, and Delaware Media Group do not recommend the use of any agent outside of the labeled indications. The opinions expressed in the educational activity are those of the faculty and do not necessarily represent the views of CMSC, NPA, or Delaware Media Group. Disclaimer: Participants have an implied responsibility to use the newly acquired information to enhance patient outcomes and their own professional development. The information presented in this activity is not meant to serve as a guideline for patient management. Any medications, diagnostic procedures, or treatments discussed in this publication should not be used by clinicians or other health-care professionals without first evaluating their patients' conditions, considering possible contraindications or risks, reviewing any applicable manufacturer's product information, and comparing any therapeutic approach with the recommendations of other authorities.