Recanalization of Acute and Subacute Venous and Synthetic Bypass-Graft Occlusions With a Mechanical Rotational Catheter

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

Wissgott, Christian, E-mail: cwissgott@wkk-hei.de; Kamusella, Peter; Andresen, Reimer

2013-08-01

PurposePercutaneous mechanical thrombectomy (PMT) is now established as an alternative treatment of acute arterial occlusions in addition to fibrinolysis and surgical thrombectomy. The objective of this retrospective study was the investigation of a rotational atherothrombectomy catheter in terms of safety and efficacy in the treatment of acute and subacute femoropopliteal bypass occlusions.Materials and MethodsForty-two patients (average age 65.8 {+-} 9.1 years) with acute (<14 days [n = 31]) and subacute (14-42 days [n = 11]) femoropopliteal bypass occlusions were treated consecutively with a rotational debulking and removal catheter (Straub Rotarex). The average occlusion length was 28.4 {+-} 2.9 (24-34) cm.more » Thirty-four (81 %) patients underwent venous bypass, and 8 (19 %) patients underwent polytetrafluoroethylene bypass.ResultsThe technical success rate was 97.6 % (41 of 42). In 1 patient, blood flow could not be restored despite the use of the atherothrombectomy system. The average catheter intervention time was 6.9 {+-} 2.1 (4-9) min. Ankle-brachial index increased from 0.39 {+-} 0.13 to 0.83 {+-} 0.11 at discharge and to 0.82 {+-} 0.17 after 1 month (p < 0.05). There were a total of 2 (4.8 %) peri-interventional complications: One patient developed a distal embolism, which was successfully treated with local lysis, and another patient had a small perforation at the distal anastomosis, which was successfully treated with a stent.ConclusionPMT with the Rotarex atherothrombectomy catheter represents a safe and effective option in the treatment of acute and subacute femoropopliteal bypass occlusions because it can quickly restore blood flow.« less

Intervention targeted at nurses to improve venous thromboprophylaxis.

PubMed

Labarere, Jose; Bosson, Jean-Luc; Sevestre, Marie-Antoinette; Sellier, Elodie; Richaud, Cecile; Legagneux, Annie

2007-10-01

To assess the effectiveness of an intervention targeting both physicians and nurses vs. physicians only in improving venous thromboprophylaxis for older patients. Cluster randomized trial. Fifty hospital-based post-acute care departments in France. Patients aged 65 years or older. A multifaceted intervention to implement a clinical practice guideline addressing venous thromboprophylaxis. The effectiveness outcomes were elastic stocking use, ambulation or mobilization under the supervision of a physical therapist and anticoagulant-based prophylaxis. Patient outcomes included deep vein thrombosis and anticoagulant-related adverse events. One department allocated to the intervention targeted at physicians only and seven departments allocated to the intervention targeted at both physicians and nurses dropped out of the study. Compared with the intervention targeted at physicians only (n = 497 patients), the intervention targeted at both physicians and nurses (n = 315 patients) was associated with a higher rate of mobilization (62 vs. 37%, P < 0.001) and comparable levels of elastic stocking (32 vs. 39%, P = 0.74) and anticoagulant (55 vs. 48%, P = 0.36) use. The rates of deep vein thrombosis (15 vs. 13%, P = 0.50), bleeding (1 vs. 1%, P = 0.99) and thrombocytopaenia (0 vs. 0.2%, P = 0.99) did not differ between the two groups. A multifaceted intervention targeting nurses in addition to physicians can increase the frequency of mobilization of older patients to prevent venous thromboembolism but does not alter the use of elastic stockings and anticoagulant. A differential drop-out of departments might have contributed to creating imbalances in baseline characteristics and outcomes in this study.

Comparison of NIRS, laser Doppler flowmetry, photoplethysmography, and pulse oximetry during vascular occlusion challenges.

PubMed

Abay, T Y; Kyriacou, P A

2016-04-01

Monitoring changes in blood volume, blood flow, and oxygenation in tissues is of vital importance in fields such as reconstructive surgery and trauma medicine. Near infrared spectroscopy (NIRS), laser Doppler (LDF) flowmetry, photoplethysmography (PPG), and pulse oximetry (PO) contribute to such fields due to their safe and noninvasive nature. However, the techniques have been rarely investigated simultaneously or altogether. The aim of this study was to investigate all the techniques simultaneously on healthy subjects during vascular occlusion challenges. Sensors were attached on the forearm (NIRS and LDF) and fingers (PPG and PO) of 19 healthy volunteers. Different degrees of vascular occlusion were induced by inflating a pressure cuff on the upper arm. The responses of tissue oxygenation index (NIRS), tissue haemoglobin index (NIRS), flux (LDF), perfusion index (PPG), and arterial oxygen saturation (PO) have been recorded and analyzed. Moreover, the optical densities were calculated from slow varying dc PPG, in order to distinguish changes in venous blood volumes. The indexes showed significant changes (p  <  0.05) in almost all occlusions, either venous or over-systolic occlusions. However, differentiation between venous and arterial occlusion by LDF may be challenging and the perfusion index (PI) may not be adequate to indicate venous occlusions. Optical densities may be an additional tool to detect venous occlusions by PPG.

High-Flow Arterio-Hepatic Venous Shunt in Hepatocellular Carcinoma: Use of Multi-Electrode Radiofrequency for Shunt Obliteration

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

Pua, Uei, E-mail: druei@yahoo.com

2015-10-15

Intra-tumoral arterio-hepatic venous shunting (AHVS) poses an impediment to transarterial chemoembolization of liver tumors. Not only does it present a potential hazard for systemic shunting and embolization, but also the altered flow dynamics may also result in poor delivery of drug/embolics to the target tumor bed. Current available techniques to overcome AVHS include arterial embolization (particles, coils, glue, etc.) or temporary venous occlusion using balloons. We hereby illustrate the use of radiofrequency ablation to obliterate a complex AHVS consisting of a varix-like venous aneurysm.

Laser targeted photo-occlusion of rat choroidal neovascularization without collateral damage.

PubMed

Nishiwaki, Hirokazu; Zeimer, Ran; Goldberg, Morton F; D'Anna, Salvatore A; Vinores, Stanley A; Grebe, Rhonda

2002-02-01

Laser targeted photo-occlusion (LTO) is a novel method being developed to treat choroidal neovascular membranes (CNV) in age-related and other macular degenerations. A photosensitive agent, encapsulated in heat-sensitive liposomes, is administered intravenously. A low power laser warms the targeted tissue and releases a bolus of photosensitizer. The photosensitizer is activated after it clears from the normal choriocapillaris but not from the CNV. Forty-five experimental CNV were induced in seven rats. Five weeks after LTO, complete occlusion was observed by laser targeted angiography (LTA) in 76% of treated CNV, and partial occlusion was found in the remaining 24%. The tissues outside the CNV but within the area treated by LTO showed no flow alteration and no dye leakage. All untreated CNV were patent on LTA at 5 weeks. Light microscopy and electron microscopy confirmed the results in treated and control lesions. Moreover, treated areas next to lesions showed normal photoreceptors, retinal pigment epithelium (RPE), Bruch's membrane and choriocapillaris. These results indicate that LTO may improve current photodynamic therapy by alleviating the need for repeated treatments and by avoiding the long-term risks associated with damage to the RPE and occlusion of normal choriocapillaries.

Sharp Central Venous Recanalization by Means of a TIPS Needle

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

Honnef, Dagmar, E-mail: honnef@rad.rwth-aachen.de; Wingen, Markus; Guenther, Rolf W.

The purpose of this study was to perform an alternative technique for recanalization of a chronic occlusion of the left brachiocephalic vein that could not be traversed with a guidewire. Restoration of a completely thrombosed left brachiocephalic vein was attempted in a 76-year-old male hemodialysis patient with massive upper inflow obstruction, massive edema of the face, neck, shoulder, and arm, and occlusion of the stented right brachiocephalic vein/superior vena cava. Vessel negotiation with several guidewires and multipurpose catheters proved unsuccessful. The procedure was also non-viable using a long, 21G puncture needle. Puncture of the superior vena cava (SVC) at themore » distal circumference of the stent in the right brachiocephalic vein/superior vena cava, however, was feasible with a transjugular intrahepatic portosystemic shunt (TIPS) set under biplanar fluoroscopy using the distal end of the right brachiocephalic vein as a target, followed by balloon dilatation and partial extraction of thrombotic material of the left brachiocephalic vein with a wire basket. Finally, two overlapping stents were deployed to avoid early re-occlusion. Venography demonstrated complete vessel patency with free contrast media flow via the stents into the SVC, which was reconfirmed in follow-up examinations. Immediate clinical improvement was observed. Venous vascular recanalization of chronic venous occlusion by means of a TIPS needle is feasible as a last resort under certain precautions.« less

Extrapolation of vertical target motion through a brief visual occlusion.

PubMed

Zago, Myrka; Iosa, Marco; Maffei, Vincenzo; Lacquaniti, Francesco

2010-03-01

It is known that arbitrary target accelerations along the horizontal generally are extrapolated much less accurately than target speed through a visual occlusion. The extent to which vertical accelerations can be extrapolated through an occlusion is much less understood. Here, we presented a virtual target rapidly descending on a blank screen with different motion laws. The target accelerated under gravity (1g), decelerated under reversed gravity (-1g), or moved at constant speed (0g). Probability of each type of acceleration differed across experiments: one acceleration at a time, or two to three different accelerations randomly intermingled could be presented. After a given viewing period, the target disappeared for a brief, variable period until arrival (occluded trials) or it remained visible throughout (visible trials). Subjects were asked to press a button when the target arrived at destination. We found that, in visible trials, the average performance with 1g targets could be better or worse than that with 0g targets depending on the acceleration probability, and both were always superior to the performance with -1g targets. By contrast, the average performance with 1g targets was always superior to that with 0g and -1g targets in occluded trials. Moreover, the response times of 1g trials tended to approach the ideal value with practice in occluded protocols. To gain insight into the mechanisms of extrapolation, we modeled the response timing based on different types of threshold models. We found that occlusion was accompanied by an adaptation of model parameters (threshold time and central processing time) in a direction that suggests a strategy oriented to the interception of 1g targets at the expense of the interception of the other types of tested targets. We argue that the prediction of occluded vertical motion may incorporate an expectation of gravity effects.

Catheter Occlusion in Home Infusion: The Influence of Needleless Connector Design on Central Catheter Occlusion.

PubMed

Williams, Ann

Thrombotic catheter occlusion is a common complication associated with central venous catheters (CVCs). A wide variety of needleless connectors that differ greatly in design and function are available for use with CVCs; however, there are a limited number of studies comparing the catheter occlusion rate associated with differently designed needleless connectors. This retrospective observational study compared occlusion rates associated with a split-septum neutral-displacement needleless connector versus those of a solid-surface neutral-reflux needleless connector in patients undergoing home infusion therapy. The neutral-reflux needleless connector was associated with a significant reduction in occlusion rate and thrombolytic use versus the neutral-displacement needleless connector.

Occlusion handling framework for tracking in smart camera networks by per-target assistance task assignment

NASA Astrophysics Data System (ADS)

Bo, Nyan Bo; Deboeverie, Francis; Veelaert, Peter; Philips, Wilfried

2017-09-01

Occlusion is one of the most difficult challenges in the area of visual tracking. We propose an occlusion handling framework to improve the performance of local tracking in a smart camera view in a multicamera network. We formulate an extensible energy function to quantify the quality of a camera's observation of a particular target by taking into account both person-person and object-person occlusion. Using this energy function, a smart camera assesses the quality of observations over all targets being tracked. When it cannot adequately observe of a target, a smart camera estimates the quality of observation of the target from view points of other assisting cameras. If a camera with better observation of the target is found, the tracking task of the target is carried out with the assistance of that camera. In our framework, only positions of persons being tracked are exchanged between smart cameras. Thus, communication bandwidth requirement is very low. Performance evaluation of our method on challenging video sequences with frequent and severe occlusions shows that the accuracy of a baseline tracker is considerably improved. We also report the performance comparison to the state-of-the-art trackers in which our method outperforms.

Efficacy and safety of using L-cysteine as a catheter-clearing agent for nonthrombotic occlusions of central venous catheters in children.

PubMed

Pai, Vinita B; Plogsted, Steven

2014-10-01

Critically ill pediatric patients, especially in the intensive care unit, receive multiple medications and have a higher risk of central venous catheter (CVC) occlusion. If an occlusion occurs immediately after the administration of multiple medications or incompatible medications, either an acidic solution such as 0.1 N hydrochloric acid (HCl) or a basic solution of 1 mEq/mL sodium bicarbonate or 0.1 N sodium hydroxide can be used. However, compounding and storing of 0.1 N HCl has become more complex due to USP <797> guidelines for sterile compounding, and an alternative is needed. We report a series of cases in which L-cysteine was used instead of HCl to clear CVCs occluded due to administration of multiple medications. L-cysteine is a commercially available, sterile solution with a pH of 1–2.5. CVC occlusion was resolved in 10 of the 16 episodes in 13 patients. Two of the 16 occlusions were phenytoin related and would not have responded. An L-cysteine dose of 50 mg was used during 10 of the 16 episodes, 100 mg during 5 episodes, and 25 mg during 1 episode. A correlation between catheter clearance and dose was not observed. Occlusion resolution due to L-cysteine was not correlated to the prior use of tissue plasminogen activator. Metabolic acidosis, adverse effects, or damage to the catheters due to L-cysteine were not observed. On the basis of this limited experience, we propose L-cysteine as an effective alternative to 0.1 N HCl for clearing CVC occlusions caused by drugs with an acidic pKa.

Risk Factors for Vascular Occlusive Events and Death Due to Bleeding in Trauma Patients; an Analysis of the CRASH-2 Cohort

PubMed Central

Pealing, Louise; Perel, Pablo; Prieto-Merino, David; Roberts, Ian

2012-01-01

Background Vascular occlusive events can complicate recovery following trauma. We examined risk factors for venous and arterial vascular occlusive events in trauma patients and the extent to which the risk of vascular occlusive events varies with the severity of bleeding. Methods and Findings We conducted a cohort analysis using data from a large international, double-blind, randomised, placebo-controlled trial (The CRASH-2 trial) [1]. We studied the association between patient demographic and physiological parameters at hospital admission and the risk of vascular occlusive events. To assess the extent to which risk of vascular occlusive events varies with severity of bleeding, we constructed a prognostic model for the risk of death due to bleeding and assessed the relationship between risk of death due to bleeding and risk of vascular occlusive events. There were 20,127 trauma patients with outcome data including 204 (1.01%) patients with a venous event (pulmonary embolism or deep vein thrombosis) and 200 (0.99%) with an arterial event (myocardial infarction or stroke). There were 81 deaths due to vascular occlusive events. Increasing age, decreasing systolic blood pressure, increased respiratory rates, longer central capillary refill times, higher heart rates and lower Glasgow Coma Scores (all p<0.02) were strong risk factors for venous and arterial vascular occlusive events. Patients with more severe bleeding as assessed by predicted risk of haemorrhage death had a greatly increased risk for all types of vascular occlusive event (all p<0.001). Conclusions Patients with severe traumatic bleeding are at greatly increased risk of venous and arterial vascular occlusive events. Older age and blunt trauma are also risk factors for vascular occlusive events. Effective treatment of bleeding may reduce venous and arterial vascular occlusive complications in trauma patients. PMID:23251374

Incidence of Central Vein Stenosis and Occlusion Following Upper Extremity PICC and Port Placement

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

Gonsalves, Carin F., E-mail: Carin.Gonsalves@mail.tju.edu; Eschelman, David J.; Sullivan, Kevin L.

2003-04-15

The purpose of this study was to determine the incidence of central vein stenosis and occlusion following upper extremity placement of peripherally inserted central venous catheters(PICCs) and venous ports. One hundred fifty-four patients who underwent venography of the ipsilateral central veins prior to initial and subsequent venous access device insertion were retrospectively identified. All follow-up venograms were interpreted at the time of catheter placement by one interventional radiologist over a 5-year period and compared to the findings on initial venography. For patients with central vein abnormalities, hospital and home infusion service records and radiology reports were reviewed to determine cathetermore » dwelltime and potential alternative etiologies of central vein stenosis or occlusion. The effect of catheter caliber and dwell time on development of central vein abnormalities was evaluated. Venography performed prior to initial catheter placement showed that 150 patients had normal central veins. Three patients had central vein stenosis, and one had central vein occlusion. Subsequent venograms (n = 154)at the time of additional venous access device placement demonstrated 8 patients with occlusions and 10 with stenoses. Three of the 18 patients with abnormal follow-up venograms were found to have potential alternative causes of central vein abnormalities. Excluding these 3 patients and the 4 patients with abnormal initial venograms, a 7% incidence of central vein stenosis or occlusion was found in patients with prior indwelling catheters and normal initial venograms. Catheter caliber showed no effect on the subsequent development of central vein abnormalities. Patients who developed new or worsened central vein stenosis or occlusion had significantly (p =0.03) longer catheter dwell times than patients without central vein abnormalities. New central vein stenosis or occlusion occurred in 7% of patients following upper arm placement of venous access

[Complications associated to central venous catheters in hematology patients].

PubMed

García-Gabás, Carmen; Castillo-Ayala, Ana; Hinojo-Marín, Begoña; Muriel-Abajo, M Ángeles; Gómez-Gutiérrez, Isabel; de Mena-Arenas, Ana M; Rodríguez-Gonzalo, Ana; Chao-Lozano, Cristina; García-Menéndez, Carmen; Madroñero-Agreda, M Antonia

2015-01-01

To discover the incidence of central venous catheters (tunnelled, subcutaneous and PICC) in patients with onco-hematological conditions, hospitalized in the Hematology or Transplantations of Hematopoietic Stem Cells Units, in two tertiary care hospitals. A cross-sectional, descriptive study form was developed in order to gather sociodemographic, clinical data as well as complications and follow-up of the care protocol. Each catheter was assigned a correlative identification number. Information was collected on 366 catheters: 185 in the University Hospital Ramón y Cajal (HURYC), 80 tunnelled, 40 subcutaneous venous access and 65 PICC, and 181 in the University Hospital Gregorio Marañón (HUGM), 101 tunnelled and 80 subcutaneous venous access. Major complications in the tunnellized were infections (13.7% in HURYC vs. 6.8% in HUGM - p<0.001) and occlusions (at least once in 3.8% vs. 21.8%). In subcutaneous venous access, infections were confirmed in 5% in HURYC vs. 1.2% in HUGM. There were occlusions at least once in 10% in HUGM and no other significant complications were detected. Regarding PICC, information was only collected in HURYC, where complications were phlebitis 10.8%, thrombosis 7.7%, confirmed or suspected infection 4.6%, occlusion at least once 7.7%. Differences between hospitals with regard to major complications, infection and occlusion may be related to different care protocol. We need to stress the high incidence of phlebitis and thrombosis in PICC catheters, compared with data of lower incidence of other papers. Copyright © 2015 Elsevier España, S.L.U. All rights reserved.

Pretreatment with remifentanil, fentanyl, or lidocaine to prevent withdrawal after rocuronium using venous occlusion technique in children and adolescents: a prospective randomized placebo-controlled double-blind study.

PubMed

Abu-Halaweh, S A; Aloweidi, A K; Qudaisat, I Y; Al-Hussami, M O; Al Zaben, K R; Abu-Halaweh, A S

2014-12-01

Pain caused by intravenous injection of the muscle relaxant rocuronium bromide is common in children and adolescents. The cause of this unwanted effect is still unclear, and different pretreatment drugs have been administered in attempts to alleviate this side effect, with varying degrees of success. This study used a 60-s venous occlusion technique to evaluate the effectiveness of pretreatment with lidocaine, fentanyl, or remifentanil in preventing pain-induced withdrawal caused by intravenous injection of rocuronium bromide during the induction of general anesthesia. One hundred and one child and adolescent patients, ASA Ι-II, requiring various surgical procedures under general anesthesia with muscle relaxation and mechanical ventilation, were enrolled. Patients were allocated randomly using computer-generated randomization into one of four pretreatment groups: a remifentanil group (1 µg/kg, n = 25), fentanyl group (1 µg/kg, n = 26), lidocaine 1% group (0.5 mg/kg, n = 25), and normal saline group (n = 25). Drug doses were prepared in normal saline to a total volume of 5 ml. Venous occlusion was applied 10 cm above the venous access site. Pretreatment drugs were injected and retained for 60 s at the site of injection by an anesthetist blinded to group allocation. After release of the tourniquet, rocuronium (0.5 mg/kg) was then injected over 5 s, and withdrawal was recorded by another anesthetist blinded to group allocation. Descriptive statistics, analysis of variance, and a chi-squared test were used to statistically analyze the results as appropriate. Compared to normal saline, all other pretreatment groups scored a significantly lower mean of withdrawal response (P < 0.001). Lidocaine was superior to both remifentanil (P < 0.05) and fentanyl (P < 0.05) in suppressing the withdrawal response to rocuronium injection. Remifentanil was superior to fentanyl in suppressing the withdrawal response caused by rocuronium injection (P < 0.001). Using a venous occlusion

Electrical characterization of conductive textile materials and its evaluation as electrodes for venous occlusion plethysmography.

PubMed

Goy, C B; Dominguez, J M; Gómez López, M A; Madrid, R E; Herrera, M C

2013-08-01

The ambulatory monitoring of biosignals involves the use of sensors, electrodes, actuators, processing tools and wireless communication modules. When a garment includes these elements with the purpose of recording vital signs and responding to specific situations it is call a 'Smart Wearable System'. Over the last years several authors have suggested that conductive textile material (e-textiles) could perform as electrode for these systems. This work aims at implementing an electrical characterization of e-textiles and an evaluation of their ability to act as textile electrodes for lower extremity venous occlusion plethysmography (LEVOP). The e-textile electrical characterization is carried out using two experimental set-ups (in vitro evaluation). Besides, LEVOP records are obtained from healthy volunteers (in vivo evaluation). Standard Ag/AgCl electrodes are used for comparison in all tests. Results shown that the proposed e-textiles are suitable for LEVOP recording and a good agreement between evaluations (in vivo and in vitro) is found.

Outcome of transarterial treatment of dural arteriovenous fistulas with direct or indirect cortical venous drainage.

PubMed

Mantilla, Daniel; Le Corre, Marine; Cagnazzo, Federico; Gascou, Gregory; Eker, Omer; Machi, Paolo; Riquelme, Carlos; Dargazanli, Cyril; Costalat, Vincent; Bonafe, Alain; Lefevre, Pierre-Henri

2018-01-30

Transarterial Onyx embolization is an effective treatment for patients with intracranial dural arteriovenous fistula (DAVF). A study was performed to determine whether the clinical and radiological outcomes after transarterial Onyx treatment were affected by the type of cortical venous drainage (direct vs indirect) of high-grade DAVF. Between May 2006 and December 2014, demographic data, clinical presentation, angiographic characteristics, and treatment-related outcomes were collected for 54 patients divided into two groups (intracranial DAVF with direct and indirect cortical venous drainage). Continuous variables were compared with the two-tailed t test and categorical variables with the χ 2 test. Statistical significance was set at P<0.05. Fifty-two patients (71% with direct and 29% with indirect cortical venous drainage) underwent Onyx embolization. Immediate complete occlusion after treatment was observed in about 55% of patients without between-group difference. During the long-term follow-up, complete angiographic occlusion was achieved in 83% of patients. Specifically, 15 additional patients (40%) in the direct cortical venous drainage group progressed to complete occlusion, but only one (6%) in the indirect cortical venous drainage group. Overall, the rate of complete occlusion was higher in patients with DAVF with direct cortical venous drainage (92%) than in those with DAVF with indirect cortical venous drainage (62.5%) (P=0.01). The rate of permanent treatment-related complications was 4%, mostly related to ischemic events. Overall, 80.5% of patients had a good neurological outcome (modified Rankin Scale score 0-2). Transarterial Onyx embolization of intracranial high-grade DAVF is safe and effective, particularly for lesions with direct cortical venous drainage. © Article author(s) (or their employer(s) unless otherwise stated in the text of the article) 2018. All rights reserved. No commercial use is permitted unless otherwise expressly granted.

Case report: Unilateral conduction hearing loss due to central venous occlusion.

PubMed

Ribeiro, Phillip; Patel, Swetal; Qazi, Rizwan A

2016-05-07

Central venous stenosis is a well-known complication in patients with vascular access for hemodialysis. We report two cases involving patients on hemodialysis with arteriovenous fistulas who developed reversible unilateral conductive hearing loss secondary to critical stenosis of central veins draining the arteriovenous dialysis access. A proposed mechanism for the patients' reversible unilateral hearing loss is pterygoid venous plexus congestion leading to decreased Eustachian tube patency. Endovascular therapy was conducted to treat the stenosis and the hearing loss of both patients was returned to near normal after successful central venous angioplasty.

Novel experience of laser-assisted 'inside-out' central venous access in a patient with bilateral subclavian vein occlusion requiring pacemaker implantation.

PubMed

Aye, Thandar; Phan, Thanh Trung; Muir, Douglas Findlay; Linker, Nicholas John; Hartley, Richard; Turley, Andrew John

2017-10-01

This new laser facilitated 'inside-out' technique was used for transvenous pacemaker insertion in a pacemaker-dependent patient with bilateral subclavian occlusion and a failed epicardial system who is not suitable for a transfemoral approach. Procedure was undertaken under general anaesthesia with venous access obtained from right femoral vein and left axillary vein. 7F multipurpose catheter was used to enter proximal edge of the occluded segment of subclavian vein via femoral approach, which then supported stiff angioplasty wires and microcatheters to tunnel into the body of occlusion. When encountered with impenetrable resistance, 1.4 mm Excimer laser helped delivery of a Pilot 200 wire, which then progressed towards the distal edge of occlusion. Serial balloon dilatations allowed wire tracked into subintimal plane, advanced towards left clavicle using knuckle wire technique, which was then externalized with blunt dissection from infraclavicular pocket area. It was later changed to Amplatz superstiff wire exiting from both ends to form a rail, which ultimately allowed passage of pacing leads after serial balloon dilatation from clavicular end. Our hybrid 'inside-out' technique permitted transvenous pacemaker insertion without complication and this is, to our knowledge, the first case using laser in this context. Published on behalf of the European Society of Cardiology. All rights reserved. © The Author 2016. For permissions please email: journals.permissions@oup.com.

Central line-associated venous late effects in children without prior history of thrombosis.

PubMed

Ruud, Ellen; Holmstrøm, Henrik; Hopp, Einar; Wesenberg, Finn

2006-09-01

The frequency of asymptomatic central line-associated thromboses is high and well recognized among children with cancer, while the long-term consequences are mainly unknown. In a cross-sectional study, we evaluated clinical and radiological venous outcome in children with previous long-standing intravascular catheters. The study enrolled 71 children previously treated for malignant or haematological diseases, 4-180 (median 37) mo after removal of their central lines. Inclusion criteria were a prior central line in a jugular vein for a minimum of 6 mo and no previous history of thrombosis. The children had clinical examination for post-thrombotic syndrome (PTS) and Doppler ultrasonography of the central neck veins. Twelve children had additional venous magnetic resonance imaging (MRI). But no kind of venography was performed in the remaining. We observed mild PTS with increased superficial collaterals in four children (6%), but no cases of more severe PTS. None complained of symptoms related to venous late effects. By ultrasonography, post-thrombotic venous alterations were detected in 17 children (24%), and five of these had complete occlusion of the veins. The sensitivity for pathologically increased collaterals to identify occlusive thrombosis was 0.6, while the specificity was 0.98. Occlusive venous thromboembolism was associated with the total number of central venous lines (CVLs; p=0.002), previous severe CVL-associated infections (p=0.001) and duration of central line in place (p=0.042). In spite of no prior history of thrombosis, children with previous long-term jugular lines frequently had local thrombotic sequelae, while clinical symptoms of PTS were rare.

Venous leg ulcers

PubMed Central

2011-01-01

Introduction Leg ulcers usually occur secondary to venous reflux or obstruction, but 20% of people with leg ulcers have arterial disease, with or without venous disorders. Between 1.5 and 3.0/1000 people have active leg ulcers. Prevalence increases with age to about 20/1000 in people aged over 80 years. Methods and outcomes We conducted a systematic review and aimed to answer the following clinical questions: What are the effects of standard treatments, adjuvant treatments, and organisational interventions for venous leg ulcers? What are the effects of advice about self-help interventions in people receiving usual care for venous leg ulcers? What are the effects of interventions to prevent recurrence of venous leg ulcers? We searched: Medline, Embase, The Cochrane Library, and other important databases up to June 2011 (Clinical Evidence reviews are updated periodically; please check our website for the most up-to-date version of this review). We included harms alerts from relevant organisations such as the US Food and Drug Administration (FDA) and the UK Medicines and Healthcare products Regulatory Agency (MHRA). Results We found 101 systematic reviews, RCTs, or observational studies that met our inclusion criteria. We performed a GRADE evaluation of the quality of evidence for interventions. Conclusions In this systematic review we present information relating to the effectiveness and safety of the following interventions: compression bandages and stockings, cultured allogenic (single or bilayer) skin replacement, debriding agents, dressings (cellulose, collagen, film, foam, hyaluronic acid-derived, semi-occlusive alginate), hydrocolloid (occlusive) dressings in the presence of compression, intermittent pneumatic compression, intravenous prostaglandin E1, larval therapy, laser treatment (low-level), leg ulcer clinics, multilayer elastic system, multilayer elastomeric (or non-elastomeric) high-compression regimens or bandages, oral treatments (aspirin, flavonoids

Venous thromboembolism does not share familial susceptibility with retinal vascular occlusion or glaucoma: a nationwide family study.

PubMed

Zöller, Bengt; Li, Xinjun; Sundquist, Jan; Sundquist, Kristina

2016-11-01

Inherited hypercoagulable states (i.e. thrombophilia) have been suggested to be involved in retinal vascular occlusion but results are divergent. Vascular micronutrition and ischemia have been hypothesised to be involved in the pathogenesis of glaucoma. This nationwide study determines the importance of family history of venous thromboembolism (VTE) as a risk factor for retinal vein occlusion (RVO), retinal artery occlusion (RAO), primary open angle glaucoma (POAG) and primary angle-closure glaucoma (PACG). A total of 6,007,042 Swedish individuals were studied. Data from the Swedish Multigeneration Register for subjects aged 0-78 years old for the period 1997-2010 were linked to the Swedish Hospital Discharge Register and the Hospital Outpatient Register. Main exposure measure was family history of VTE in first-degree relatives (parents and/or siblings). Main outcomes were hazard ratios (HRs) for RVO, RAO, POAG, and PACG. During follow-up 9036 individuals developed RVO, 2137 individuals developed RAO, 29,176 individuals developed POAG and 1498 individuals developed PACG. There was no association between family history of VTE and risk of RVO (HR = 1.04, 95 % CI 0.98-1.10), RAO (HR = 1.00, 95 % CI 0.89-1.13), POAG (HR = 0.96, 95 % CI 0.93-0.99), and PACG (HR = 0.92, 95 % CI 0.80-1.06) in the crude age and sex adjusted model. The results were similar in the fully adjusted model: RVO (HR = 1.04, 95 % CI 0.99-1.11), RAO (HR = 1.01, 95 % CI 0.89-1.13), POAG (HR = 0.97, 95 % CI 0.94-1.00), and PACG (HR = 0.91, 95 % CI 0.79-1.05). Family history of VTE is not a risk factor for RVO, RAO, POAG and PACG. Thus, it is unlikely that strong and common genetic variants associated with VTE are of importance for these disorders.

Is It Worthwhile Treating Occluded Cold Stored Venous Allografts by Thrombolysis?

PubMed

Balaz, P; Wohlfahrt, P; Rokosny, S; Maly, S; Bjorck, M

2016-09-01

Thrombolysis has been reported to be suboptimal in occluded vein grafts and cryopreserved allografts, and there are no data on the efficacy of thrombolysis in occluded cold stored venous allografts. The aim was to evaluate early outcomes, secondary patency and limb salvage rates of thrombolysed cold stored venous allograft bypasses and to compare the outcomes with thrombolysis of autologous bypasses. This was a single center study of consecutive patients with acute and non-acute limb ischemia between September 1, 2000, and January 1, 2014, with occlusion of cold stored venous allografts, and between January 1, 2012, and January 1, 2014, with occlusion of autologous bypass who received intra-arterial thrombolytic therapy. Sixty-one patients with occlusion of an infrainguinal bypass using a cold stored venous allograft (n = 35) or an autologous bypass (n = 26) underwent percutaneous intra-arterial thrombolytic therapy. The median duration of thrombolysis was 20 h (IQR 18-24) with no difference between the groups (p = .14). The median follow up was 18.5 months (IQR 11.0-52.0). Secondary patency rates of thrombolysed bypass at 6 and 12 months were 44 ± 9% and 32 ± 9% in patients with a venous allograft bypass and 46 ± 10% and 22 ± 8% with an autologous bypass, with no difference between groups (p = .40). Limb salvage rates at 1, 6, and 12 months after thrombolysis in the venous allograft group were 83 ± 7%, 72 ± 8% and 63 ± 9%, and in the autologous group 91 ± 6%, 76 ± 9%, and 65 ± 13%, with no difference between groups (p = .69). Long-term results of thrombolysis of venous allograft bypasses are similar to those of autologous bypasses. Occluded cold stored venous allograft can be successfully re-opened in most cases with a favorable effect on limb salvage. Copyright © 2016 European Society for Vascular Surgery. Published by Elsevier Ltd. All rights reserved.

Venous leg ulcers

PubMed Central

2008-01-01

Introduction Leg ulcers usually occur secondary to venous reflux or obstruction, but 20% of people with leg ulcers have arterial disease, with or without venous disorders. Between 1.5 and 3.0/1000 people have active leg ulcers. Prevalence increases with age to about 20/1000 in people aged over 80 years. Methods and outcomes We conducted a systematic review and aimed to answer the following clinical questions: What are the effects of standard treatments, adjuvant treatments, and organisational interventions for venous leg ulcers? What are the effects of interventions to prevent recurrence of venous leg ulcers? We searched: Medline, Embase, The Cochrane Library, and other important databases up to September 2007 (BMJ Clinical Evidence reviews are updated periodically, please check our website for the most up-to-date version of this review). We included harms alerts from relevant organisations such as the US Food and Drug Administration (FDA) and the UK Medicines and Healthcare products Regulatory Agency (MHRA). Results We found 80 systematic reviews, RCTs, or observational studies that met our inclusion criteria. We performed a GRADE evaluation of the quality of evidence for interventions. Conclusions In this systematic review we present information relating to the effectiveness and safety of the following interventions: compression bandages and stockings, cultured allogenic (single or bilayer) skin replacement, debriding agents, dressings (cellulose, collagen, film, foam, hyaluronic acid-derived, semi-occlusive alginate), hydrocolloid (occlusive) dressings in the presence of compression, intermittent pneumatic compression, intravenous prostaglandin E1, larval therapy, laser treatment (low-level), leg ulcer clinics, multilayer elastic system, multilayer elastomeric (or non-elastomeric) high-compression regimens or bandages, oral treatments (aspirin, flavonoids, pentoxifylline, rutosides, stanozolol, sulodexide, thromboxane alpha2 antagonists, zinc), peri

The role of "rescue saccades" in tracking objects through occlusions.

PubMed

Zelinsky, Gregory J; Todor, Andrei

2010-12-29

We hypothesize that our ability to track objects through occlusions is mediated by timely assistance from gaze in the form of "rescue saccades"-eye movements to tracked objects that are in danger of being lost due to impending occlusion. Observers tracked 2-4 target sharks (out of 9) for 20 s as they swam through a rendered 3D underwater scene. Targets were either allowed to enter into occlusions (occlusion trials) or not (no occlusion trials). Tracking accuracy with 2-3 targets was ≥ 92% regardless of target occlusion but dropped to 74% on occlusion trials with four targets (no occlusion trials remained accurate; 83%). This pattern was mirrored in the frequency of rescue saccades. Rescue saccades accompanied approximatlely 50% of the Track 2-3 target occlusions, but only 34% of the Track 4 occlusions. Their frequency also decreased with increasing distance between a target and the nearest other object, suggesting that it is the potential for target confusion that summons a rescue saccade, not occlusion itself. These findings provide evidence for a tracking system that monitors for events that might cause track loss (e.g., occlusions) and requests help from the oculomotor system to resolve these momentary crises. As the number of crises increase with the number of targets, some requests for help go unsatisfied, resulting in degraded tracking.

[Venous access in oncology].

PubMed

Lesimple, T; Béguec, J F; Levêque, J M

1998-10-31

Many treatments administered to cancer patients require venous access either via a peripheral vein or a larger central vein at the risk of local or systemic infection, thrombus formation or venous occlusion and dysfunction. Insertion of a central catheter is an invasive procedure which must be conducted under conditions of rigorous asepsia. Strict rules based on well-defined protocols must be applied throughout its use. Local or systemic infectious complications account for 18 to 25% of all nosocomial infections and are often related to colonisation of the puncture site by a Gram positive germ. In case of infection, ablation of the central catheter is not mandatory for diagnosis or antibiotic treatment. Reported at varying frequencies in the literature from 4 to 42%, thrombus formation is unpredictable and often difficult to diagnose. Anticoagulants or fibrolytic agents are indicated but it may also be necessary to withdraw the catheter. Displacement, rupture, obstruction and extravasation are frequent complications. Back flow must be checked in all venous accesses and free flow carefully verified. The access must remain patent throughout the period of use, guaranteed by a standard heparinization and rinsing protocol. This complications must not mask the important progress achieved with the use of central venous access for specific and symptomatic treatment in cancer patients.

Pattern of venous collateral development after splenic vein occlusion in an extended Whipple procedure : comparison with collateral vein pattern in cases of sinistral portal hypertension.

PubMed

Strasberg, Steven M; Bhalla, Sanjeev; Sanchez, Luis A; Linehan, David C

2011-11-01

The risks of developing sinistral portal hypertension as a result of occlusion of the splenic vein close to its termination during a Whipple procedure are unclear. Our purpose was to compare the pattern of venous collateral development after splenic vein ligation in an extended Whipple procedure with the pattern of collateral development in cases of sinistral portal hypertension. Five patients underwent an extended Whipple procedure in which the splenic vein was divided and not reconstructed. Six to eight months later detailed mapping of venous return from the spleen was determined by contrast-enhanced multidetector computed tomography or in one case by 3D contrast-enhanced MRI. Spleen size and length of residual patent splenic vein were also measured. The literature on sinistral portal hypertension was evaluated to ascertain whether the venous collateral pattern in cases of left-sided portal hypertension was similar to the pattern that developed when the splenic vein was ligated at its termination in the Whipple procedure. A length of splenic vein remained patent in all five patients, measuring 4.5 to 11.5 cm from the spleen. Splenomegaly did not develop. Blood returned from the spleen by multiple collaterals including collaterals in the omentum and mesocolon. These types of collaterals do not develop in sinistral portal hypertension, nor is residual patent splenic vein seen. Ligation of the splenic vein close to its termination in five patients resulted in a pattern of venous return different from patients that have developed left-sided portal hypertension.

Sodium-hydrogen exchange in erythrocytes of patients with acute deep venous thromboses.

PubMed

Polykarpov, S A; Orlov, S N

1992-05-15

The rate of delta microH(+)-induced Na/H-exchange in erythrocytes of patients with occlusive and with floating types of acute deep venous thromboses, and in control volunteers, was estimated. In patients with occlusive thrombi Na/H-exchange was revealed to be fourfold higher in comparison with patients with floating thrombi and with controls, while no difference was observed between the two latter groups.

Limb suction evoked during arterial occlusion causes systemic sympathetic activity in humans

PubMed Central

Cui, Jian; Blaha, Cheryl; Herr, Michael D.; Drew, Rachel C.; Muller, Matthew D.

2015-01-01

Venous saline infusions in an arterially occluded forearm evokes reflex increases in muscle sympathetic nerve activity (MSNA) and blood pressure (BP). We hypothesized that the application of suction to the human limbs would activate this venous distension reflex and raise sympathetic outflow. We placed airtight pressure tanks and applied 100 mmHg negative pressure to an arterially occluded limb (occlusion and suction, O&S) to induce tissue deformation without fluid translocation. BP, heart rate (HR), and MSNA were assessed in 19 healthy subjects during 2 min of arm or leg O&S. Occlusion without suction served as a control. During a separate visit, saline (5% forearm volume) was infused into veins of the arterially occluded arm (n = 13). The O&S increased limb circumference, MSNA burst rate (arm: Δ6.7 ± 0.7; leg: Δ6.8 ± 0.7 bursts/min), and total activity (arm: Δ199 ± 14; leg: Δ172 ± 22 units/min) and BP (arm: Δ4.3 ± 0.3; leg: Δ9.4 ± 1.4 mmHg) from the baseline. The MSNA and BP responses during arm O&S correlated with those during leg O&S. Occlusion alone had no effect on MSNA and BP. MSNA (r = 0.607) responses during arm O&S correlated with those evoked by the saline infusion into the arm. These correlations suggest that sympathetic activation during limb O&S is likely, at least partially, to be evoked via the venous distension reflex. These data suggest that suction of an occluded limb evokes sympathetic activation and that the limb venous distension reflex exists in arms and legs of normal humans. PMID:26136530

Hypoplastic left heart syndrome and pulmonary veno-occlusive disease in an infant.

PubMed

D'Souza, Marise; Vergales, Jeffrey; Jayakumar, K Anitha

2013-01-01

This report describes an infant with heterotaxy syndrome and severe hypoplasia of the left heart who presented with profound cyanosis at birth despite a large patent ductus arteriosus. Pulmonary venous return was difficult to demonstrate by echocardiography. Angiography showed total anomalous pulmonary venous return via a plexus that drained through the paravertebral veins and bilateral superior vena cavae. Autopsy confirmed these findings, and histopathology demonstrated severe occlusive changes within the pulmonary veins.

Report on the Hemodialysis Reliable Outflow (HeRO) experience in dialysis patients with central venous occlusions.

PubMed

Wallace, Justin R; Chaer, Rabih A; Dillavou, Ellen D

2013-09-01

The Hemodialysis Reliable Outflow (HeRO) graft (Hemosphere/CryoLife Inc, Eden Prairie, Minn) has provided an innovative means to obtain hemodialysis access for patients with severe central venous occlusive disease. The outcomes of this novel treatment modality in a difficult population have yet to be clearly established. A retrospective review of HeRO graft placement from June 2010 to January 2012 was performed. Patient hemodialysis access history, clinical complexity, complications, and outcomes were analyzed. Categoric data were described with counts and proportions, and continuous data with means, ranges and, when appropriate, standard deviations. Patency rates were analyzed using life-table analysis, and patency rate comparisons were made with a two-group proportion comparison calculator. HeRO graft placement was attempted 21 times in 19 patients (52% women), with 18 of 21 (86%) placed successfully. All but one was placed in the upper extremity. Mean follow-up after successful placement has been 7 months (range, 0-23 months). The primary indication for all HeRO graft placements except one was central vein occlusion(s) and need for arteriovenous access. Patients averaged 2.0 previous (failed) accesses and multiple catheters. Four HeRO grafts (24%), all in women, required ligation and removal for severe steal symptoms in the immediate postoperative period (P < .01 vs men). Three HeROs were placed above fistulas for rescue. All thrombosed <4 months, although the fistulas remained open. An infection rate of 0.5 bacteremic events per 1000 HeRO-days was observed. At a mean follow-up of 7 months, primary patency was 28% and secondary patency was 44%. The observed 12-month primary and secondary patency rates were 11% and 32%, respectively. Secondary patency was maintained in four patients for a mean duration of 10 months (range, 6-18 months), with an average of 4.0 ± 2.2 thrombectomies per catheter. HeRO graft placement, when used as a last-resort measure, has been

Investigation on etiology of hepatic venous obstruction Budd-Chiari syndrome.

PubMed

Tian, Zhi-Long; Jia, Gao-Lei; Xi, Hai-Lin; Feng, Su; Wang, Xiao-Kai; Li, Rui

2014-12-01

Budd-Chiari syndrome (BCS) is an uncommon clinical condition with a complex etiology. Pathogenesis of BCS is still poorly understood. We included hepatic veno-occlusive lesion tissues of 20 patients (patients group) with hepatic venous obstruction BCS and compared with 20 similar tissues with other etiologies (control group). Morphological changes in hepatic veno-occlusive lesion tissues and the positive expression of proliferating cell nuclear antigen (PCNA), C-myc, and P-53 were observed by the pathological examination (H&E staining) and immunohistochemistry assay. Our results showed that PCNA and C-myc positive cell densities were significantly higher in patient group than control group. P-53 positive cell density showed increasing trends in patients than control group. Moreover, we observed irregular hyperplasia in intimal tissue, fibrous connective tissue, and smooth muscle cell, accompanied by tissue degeneration (hyaloid degeneration and fibrinoid degeneration) and a large quantity of inflammatory cell infiltration. In conclusion, an overexpression of PCNA, C-myc, and a weak positive expression of P53 might launch the extremely irregular hepatic venous intimal hyperplasia, which is probably one of the etiologies of hepatic venous obstruction BCS.

Pedal angiography in peripheral arterial occlusive disease: first-pass i.v. contrast-enhanced MR angiography with blood pool contrast medium versus intraarterial digital subtraction angiography.

PubMed

Kos, Sebastian; Reisinger, Clemens; Aschwanden, Markus; Bongartz, Georg M; Jacob, Augustinus L; Bilecen, Deniz

2009-03-01

The purpose of this study was to prospectively evaluate first-pass i.v. gadofosveset-enhanced MR angiography in patients with peripheral arterial occlusive disease for visualization of the pedal arteries and stenosis or occlusion of those arteries with intraarterial digital subtraction angiography as the reference standard. Twenty patients with peripheral arterial occlusive disease (nine women, 11 men; age-range 58-83 years) were prospectively enrolled. Gadofosveset first-pass contrast-enhanced MR angiography was performed with a 1.5-T system, a dedicated foot coil, and cuff compression to the calf. Arterial segments were assessed for degree of arterial stenosis, arterial visibility, diagnostic utility, and venous contamination. Detection of vessel stenosis or occlusion was evaluated in comparison with findings at digital subtraction angiography. The unpaired Student's t test was used to test arterial visibility with the two techniques. First-pass MR angiography with gadofosveset had good diagnostic utility in 83.9% of all segments and no venous contamination in 96.8% of all segments. There was no difference between the performance of intraarterial digital subtraction angiography and that of i.v. contrast-enhanced MR angiography in arterial visibility overall (p = 0.245) or in subgroup analysis of surgical arterial bypass targets (p = 0.202). The overall sensitivity, specificity, and accuracy of i.v. gadofosveset-enhanced MR angiography for characterization of clinically significant stenosis and occlusion were 91.4%, 96.1%, and 93.9%. In the subgroup analysis, the sensitivity, specificity, and accuracy were 85.5%, 96.5%, and 92.1%. Gadofosveset-enhanced MR angiography of the pedal arteries in patients with peripheral arterial occlusive disease has arterial visibility equal to that of digital subtraction angiography and facilitates depiction of clinically significant stenosis and occlusion.

Veno-occlusive disease in snow leopards (Panthera uncia) from zoological parks.

PubMed

Munson, L; Worley, M B

1991-01-01

Livers from 54 snow leopards, 4 days to 23 years old, that had died in 23 US zoos, were evaluated histopathologically to determine if the hepatic fibrosis, which has been noted to be prevalent in this species, was due to chronic active hepatitis from hepadnaviral infection, Ito cell proliferation, or hemosiderosis. Forty-two of 54 snow leopards had subintimal vascular fibrosis with partial or total occlusion of central and sublobular veins (veno-occlusive disease) of unknown origin. All 21 leopards older than 5 years were affected. Four leopards had chronic active hepatitis, and 12 leopards had cholangiohepatitis; but these lesions were not connected anatomically to central and sublobular venous fibrosis. Hepatocellular and Kupffer cell siderosis and Ito cell proliferation were prevalent and often coexisted with perisinusoidal, central, and sublobular venous fibrosis; but fibrosis was present in leopards without siderosis or Ito cell proliferation. The pattern and prevalence of veno-occlusive disease in these leopards was similar to that reported in captive cheetah (Acinonyx jubatus), suggesting that a common extrinsic factor may cause the majority of hepatic disease in these large felid animals in captivity.

ADULT WITH CHICKENPOX COMPLICATED BY SYSTEMIC VASCULITIS AND BILATERAL RETINAL VASCULITIS WITH RETINAL VASCULAR OCCLUSIONS.

PubMed

Murdock, Jennifer; Carvounis, Petros E

2017-01-01

To describe an adult with chickenpox resulting in systemic vasculitis and bilateral retinal vascular occlusions. Single case report. A 58-year-old man with chickenpox complicated by disseminated varicella-zoster systemic and retinal vasculitis resulting in a combined arterial and venous occlusion in one eye with multiple branch retinal vein occlusions in the other eye. There was no evidence of retinitis. The patient systemically improved after treatment with acyclovir and steroids; however, his vision remained poor. Chickenpox can be associated with systemic vasculopathy and may rarely result in multiple systemic and ocular infarcts, including severe retinal vascular occlusions.

Anti-fouling strategies for central venous catheters

PubMed Central

Albadawi, Hassan; Patel, Nikasha; Khademhosseini, Ali; Zhang, Yu Shrike; Naidu, Sailendra; Knuttinen, Grace; Oklu, Rahmi

2017-01-01

Central venous catheters (CVCs) are ubiquitous in the healthcare industry and carry two common complications, catheter related infections and occlusion, particularly by thrombus. Catheter-related bloodstream infections (CRBSI) are an important cause of nosocomial infections that increase patient morbidity, mortality, and hospital cost. Innovative design strategies for intravenous catheters can help reduce these preventable infections. Antimicrobial coatings can play a major role in preventing disease. These coatings can be divided into two major categories: drug eluting and non-drug eluting. Much of these catheter designs are targeted at preventing the formation of microbial biofilms that make treatment of CRBSI nearly impossible without removal of the intravenous device. Exciting developments in catheter impregnation with antibiotics as well as nanoscale surface design promise innovative changes in the way that physicians manage intravenous catheters. Occlusion of a catheter renders the catheter unusable and is often treated by tissue plasminogen activator administration or replacement of the line. Prevention of this complication requires a thorough understanding of the mechanisms of platelet aggregation, signaling and cross-linking. This article will look at the advances in biomaterial design specifically drug eluting, non-drug eluting, lubricious coatings and micropatterning as well as some of the characteristics of each as they relate to CVCs. PMID:29399528

Anti-fouling strategies for central venous catheters.

PubMed

Wallace, Alex; Albadawi, Hassan; Patel, Nikasha; Khademhosseini, Ali; Zhang, Yu Shrike; Naidu, Sailendra; Knuttinen, Grace; Oklu, Rahmi

2017-12-01

Central venous catheters (CVCs) are ubiquitous in the healthcare industry and carry two common complications, catheter related infections and occlusion, particularly by thrombus. Catheter-related bloodstream infections (CRBSI) are an important cause of nosocomial infections that increase patient morbidity, mortality, and hospital cost. Innovative design strategies for intravenous catheters can help reduce these preventable infections. Antimicrobial coatings can play a major role in preventing disease. These coatings can be divided into two major categories: drug eluting and non-drug eluting. Much of these catheter designs are targeted at preventing the formation of microbial biofilms that make treatment of CRBSI nearly impossible without removal of the intravenous device. Exciting developments in catheter impregnation with antibiotics as well as nanoscale surface design promise innovative changes in the way that physicians manage intravenous catheters. Occlusion of a catheter renders the catheter unusable and is often treated by tissue plasminogen activator administration or replacement of the line. Prevention of this complication requires a thorough understanding of the mechanisms of platelet aggregation, signaling and cross-linking. This article will look at the advances in biomaterial design specifically drug eluting, non-drug eluting, lubricious coatings and micropatterning as well as some of the characteristics of each as they relate to CVCs.

Raster-scan optoacoustic angiography reveals 3D microcirculatory changes during cuffed occlusion

NASA Astrophysics Data System (ADS)

Subochev, Pavel; Orlova, Anna; Smolina, Ekaterina; Kirillov, Aleksey; Shakhova, Natalia; Turchin, Ilya

2018-04-01

Acoustic resolution photoacoustic microscopy at the optical wavelength of 532 nm was used to investigate the functional reaction of blood vessels of healthy human skin during cuffed venous occlusion. The high bandwidth of the polyvinilidene difluoride detector provided the opportunity for raster-scan optoacoustic angiography of both the superficial and deep plexuses at the high resolution of 35/50 microns (axial/lateral). A reversible increase of blood supply in the microcirculatory bed during occlusion was revealed.

Life-threatening Cerebral Edema Caused by Acute Occlusion of a Superior Vena Cava Stent

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

Sofue, Keitaro, E-mail: keitarosofue@yahoo.co.jp; Takeuchi, Yoshito, E-mail: yotake62@qg8.so-net.ne.jp; Arai, Yasuaki, E-mail: arai-y3111@mvh.biglobe.ne.jp

A71-year-old man with advanced lung cancer developed a life-threatening cerebral edema caused by the acute occlusion of a superior vena cava (SVC) stent and was successfully treated by an additional stent placement. Although stent occlusion is a common early complication, no life-threatening situations have been reported until now. Our experience highlights the fact that acute stent occlusion can potentially lead to the complete venous shutdown of the SVC, resulting in life-threatening cerebral edema, after SVC stent placement. Immediate diagnosis and countermeasures are required.

Fulminant idiopathic intracranial hypertension and venous stasis retinopathy resulting in severe bilateral visual impairment.

PubMed

Voldman, Alexander; Durbin, Breanna; Nguyen, John; Ellis, Brian; Leys, Monique

2017-03-10

To report a complicated case of fulminant idiopathic intracranial hypertension and concomitant venous stasis retinopathy leading to postpapilledema optic atrophy. Case report. A 34-year-old morbidly obese woman with a history of idiopathic intracranial hypertension (IIH) presented with a 1-month history of bilateral vision loss, diplopia, and left eye pain after being lost to follow-up for 6 years. Fundus examination revealed florid papilledema with venous tortuosity bilaterally. Brain and orbit magnetic resonance imaging showed bilateral globe flattening, intraocular optic nerve swelling in both eyes, and no abnormality on magnetic resonance venography. After additional workup including lumbar puncture with an opening pressure of 55 cm H2O, a diagnosis of IIH was confirmed. Medical treatment with oral carbonic anhydrase inhibitors was initiated, followed by same-day bilateral optic nerve sheath decompression and ventriculoperitoneal shunt placement the following week. Fundus examination 2 months later revealed a persistent blood and thunder fundus suggestive of bilateral central retinal vein occlusions. Over the course of 6 months, both eyes displayed postpapilledema optic atrophy with light perception and hand motion vision in the right and left eyes, respectively. On Goldmann perimetry, the patient had vague limited isolated responses in both eyes to the largest target. Fulminant IIH can present with profoundly blinding complications recalcitrant to aggressive medical and surgical intervention. Central retinal vein occlusion is an uncommon blinding complication of IIH.

How to deal with atrial septal defect closure from right internal jugular vein: Role of venous-arterial circuit for sizing and over-the-wire device implantation.

PubMed

Butera, Gianfranco; Lovin, Nicusor; Basile, Domenica Paola

2017-01-01

Secundum atrial septum defect (ASD) is the most common congenital heart disease. It is usually treated by a transcatheter approach using a femoral venous access. In case of bilateral femoral vein occlusion, the internal jugular venous approach for ASD closure is an option, in particular in cases where ASD balloon occlusion test and sizing is needed. Here, we report on a new technique for ASD closure using a venous-arterial circuit from the right internal jugular vein to the femoral artery. Two patients (females, 4 and 10 years of age) had occlusion of both femoral veins because of a previous history of pulmonary atresia and intact ventricular septum, for which they underwent percutaneous radiofrequency perforation and balloon angioplasty. These subjects needed balloon occlusion test of a residual ASD to size the hole and to check for hemodynamic suitability to ASD closure. After performing a venous-arterial circuit, a 24 mm St Jude ASD sizing balloon catheter was advanced over the circuit and the defect closed for 15 min to check hemodynamics and size the defect. ASD was closed is hemodinamically suitable. This technique was safe and reliable. © 2016 Wiley Periodicals, Inc. © 2016 Wiley Periodicals, Inc.

[Digital blood flow measurement by venous occlusion plethysmography in Raynaud's phenomenon. Value of the rewarming test].

PubMed

Cristol, R; Debray, J

1986-01-01

The fingertip blood flow measured by mercury strain gauge plethysmography with venous occlusion, at 22 degrees C room temperature, had significantly lower mean values in 190 patients with Raynaud's phenomenon (55 men aged 49 yrs +/- 16, 135 women aged 48 yrs +/- 16) than in 40 age and sex matched controls: 18 ml/100 ml/minute +/- 14.6 versus 35 ml/100 ml/minute +/- 15 at level p less than 0.01. The mean fingertip blood flow was significantly lower (p less than 0.01) in 31 cases of scleroderma and 32 cases of pulpar necrosis (respectively 13 ml +/- 13 and 11 ml +/- 8) than in 55 cases of primary Raynaud's disease (no detectable etiology and normal capillaroscopy 5 years after onset) or in 34 cases of mild Raynaud's phenomenon (respectively 21.6 +/- 16 and 24.4 +/- 18). A warming test (both hands in water at 45 degrees C during 3 minutes) was performed in 50 cases with low basal fingertip blood flow. It induced a "normalized" flow in 22 cases (mostly primary or mild Raynaud), a partly improved flow in 20 cases (mostly secondary Raynaud) and no improvement in 8 cases (scleroderma). The warming test appears to be clinically useful to assess the vasospasm and the vasodilating capabilities.

Venous Intravasation: A Potential Pitfall of Confirmatory Hysterosalpingogram Following Essure Hysteroscopic Sterilization

PubMed Central

Chang, Michael C.; Shim, John J.

2012-01-01

Indications for hysterosalpingography (HSG) include evaluation of infertility, spontaneous abortions, postoperative evaluation of tubal ligation, pre-myomectomy evaluation, and more recently, evaluation of tubal occlusion after placement of the Essure Permanent Birth Control System. Here we report a case of venous intravasation during a routine post-Essure HSG, a phenomenon in which contrast transits from the uterine cavity, through the myometrium, and directly into draining pelvic veins. Venous intravasation is a potential pitfall in interpretation of HSGs. PMID:23378884

Central venous recanalization in patients with short gut syndrome: restoration of candidacy for intestinal and multivisceral transplantation.

PubMed

Lang, Elvira V; Reyes, Jorge; Faintuch, Salomao; Smith, Amy; Abu-Elmagd, Kareem

2005-09-01

To assess feasibility and success of venous recanalization in patients with short gut syndrome who have lost their traditional central venous access and required intestinal or multivisceral transplantation. Twelve patients between the ages of 7 and 55 years with short gut syndrome and long-standing total parenteral nutrition (TPN) dependency and/or hypercoagulability were treated. All had extensive chronic central venous occlusions and survival was dependent on restoration of access and planned transplantation. Central venous recanalizations were obtained via sharp needle recanalization techniques, venous reconstructions with stents, and/or extraanatomic access to the central venous system for placement of central venous tunneled catheters. Central venous access was restored in all patients without operative-related mortality. Three major hemodynamic perioperative technical complications were recorded and successfully treated. There were three self-limited early infectious complications. With a mean follow-up of 22 months, eight of the 12 patients were alive with successful small bowel or multivisceral transplantation; six of those became independent of TPN. The remaining four patients died of complications related to TPN (n = 3) or transplantation (n = 1). With a mean follow-up of 20 months, all but two of the recanalized venous accesses were maintained, for a success rate of 83%. Recanalizations of extensive chronic vein occlusions are feasible but associated with high risk. The technique is life-saving for TPN-dependent patients and can restore candidacy for intestinal and multivisceral transplantation. This approach is likely to be increasingly requested because of the current clinical availability of the transplant procedure.

Catheter interventional treatment of congenital portosystemic venous shunts in childhood.

PubMed

Knirsch, Walter; Benz, Dominik C; Bühr, Patrick; Quandt, Daniel; Weber, Roland; Kellenberger, Christian; Braegger, Christian P; Kretschmar, Oliver

2016-06-01

The study aimed on the catheter interventional treatment of congenital portosystemic venous shunt (CPSVS) in childhood and the impact on vascular growth of hypoplastic portal veins. Clinical course and follow up of partial or complete closure of CPSVS are described. CPSVS is a very rare vascular malformation of the portal venous drainage resulting in potentially life threatening abdominal, pulmonary, cerebral, and cardiac complications. The anatomic type, clinical course, and diagnosis must be determined for optimal management. Single centre case series. Eight (6 female) children with extrahepatic (n = 5) and intrahepatic (n = 3) CPSVS were diagnosed invasively by catheterization, including test balloon occlusion of the shunt and simultaneous retrograde angiography, and treated by catheter interventions (n = 5) with partial (n = 2) and complete (n = 3) occlusion of CPSVS at a median age of 3.9 years (range 0.7-21). Congenital heart disease (CHD) was the most frequent associated organ manifestation (n = 5) followed by mild to severe pulmonary arterial hypertension (n = 4), hepatopulmonary syndrome (n = 2), and portosystemic encephalopathy (n = 1). CHD was simple (n = 3) or complex type (n = 2). Three patients were untreated so far, because they were in excellent clinical condition at an age <1 year, refused treatment, or planned for later treatment. Accurate invasive diagnosis of CPSVS with test balloon occlusion of the shunt is mandatory to depict the anatomic situation. Catheter interventional treatment of CPSVS offers a feasible and safe approach with complete or partial closure of the vascular malformation inducing potentially significant vascular growth of a former hypoplastic portal venous system. © 2015 Wiley Periodicals, Inc. © 2015 Wiley Periodicals, Inc.

Progression of Diabetic Capillary Occlusion: A Model

PubMed Central

Gens, John Scott; Glazier, James A.; Burns, Stephen A.; Gast, Thomas J.

2016-01-01

An explanatory computational model is developed of the contiguous areas of retinal capillary loss which play a large role in diabetic maculapathy and diabetic retinal neovascularization. Strictly random leukocyte mediated capillary occlusion cannot explain the occurrence of large contiguous areas of retinal ischemia. Therefore occlusion of an individual capillary must increase the probability of occlusion of surrounding capillaries. A retinal perifoveal vascular sector as well as a peripheral retinal capillary network and a deleted hexagonal capillary network are modelled using Compucell3D. The perifoveal modelling produces a pattern of spreading capillary loss with associated macular edema. In the peripheral network, spreading ischemia results from the progressive loss of the ladder capillaries which connect peripheral arterioles and venules. System blood flow was elevated in the macular model before a later reduction in flow in cases with progression of capillary occlusions. Simulations differing only in initial vascular network structures but with identical dynamics for oxygen, growth factors and vascular occlusions, replicate key clinical observations of ischemia and macular edema in the posterior pole and ischemia in the retinal periphery. The simulation results also seem consistent with quantitative data on macular blood flow and qualitative data on venous oxygenation. One computational model applied to distinct capillary networks in different retinal regions yielded results comparable to clinical observations in those regions. PMID:27300722

Locating the optimal internal jugular target site for central venous line placement.

PubMed

Giordano, Chris R; Murtagh, Kevin R; Mills, Jaime; Deitte, Lori A; Rice, Mark J; Tighe, Patrick J

2016-09-01

Historically, the placement of internal jugular central venous lines has been accomplished by using external landmarks to help identify target-rich locations in order to steer clear of dangerous structures. This paradigm is largely being displaced, as ultrasound has become routine practice, raising new considerations regarding target locations and risk mitigation. Most human anatomy texts depict the internal jugular vein as a straight columnar structure that exits the cranial vault the same size that it enters the thoracic cavity. We dispute the notion that the internal jugulars are cylindrical columns that symmetrically descend into the thoracic cavity, and purport that they are asymmetric conical structures. The primary aim of this study was to evaluate 100 consecutive adult chest and neck computed tomography exams that were imaged at an inpatient hospital. We measured the internal jugular on the left and right sides at three different levels to look for differences in size as the internal jugular descends into the thoracic cavity. We revealed that as the internal jugular descends into the thorax, the area of the vessel increases and geometrically resembles a conical structure. We also reconfirmed that the left internal jugular is smaller than the right internal jugular. Understanding that the largest target area for central venous line placement is the lower portion of the right internal jugular vein will help to better target vascular access for central line placement. This is the first study the authors are aware of that depicts the internal jugular as a conical structure as opposed to the commonly depicted symmetrical columnar structure frequently illustrated in anatomy textbooks. This target area does come with additional risk, as the closer you get to the thoracic cavity, the greater the chances for lung injury. Copyright © 2016 Elsevier Inc. All rights reserved.

Blood flow vs. venous pressure effects on filtration coefficient in oleic acid-injured lung.

PubMed

Anglade, D; Corboz, M; Menaouar, A; Parker, J C; Sanou, S; Bayat, S; Benchetrit, G; Grimbert, F A

1998-03-01

On the basis of changes in capillary filtration coefficient (Kfc) in 24 rabbit lungs, we determined whether elevations in pulmonary venous pressure (Ppv) or blood flow (BF) produced differences in filtration surface area in oleic acid-injured (OA) or control (Con) lungs. Lungs were cyclically ventilated and perfused under zone 3 conditions by using blood and 5% albumin with no pharmacological modulation of vascular tone. Pulmonary arterial, venous, and capillary pressures were measured by using arterial, venous, and double occlusion. Before and during each Kfc-measurement maneuver, microvascular/total vascular compliance was measured by using venous occlusion. Kfc was measured before and 30 min after injury, by using a Ppv elevation of 7 cmH2O or a BF elevation from 1 to 2 l . min-1 . 100 g-1 to obtain a similar double occlusion pressure. Pulmonary arterial pressure increased more with BF than with Ppv in both Con and OA lungs [29 +/- 2 vs. 19 +/- 0.7 (means +/- SE) cmH2O; P < 0. 001]. In OA lungs compared with Con lungs, values of Kfc (200 +/- 40 vs. 83 +/- 14%, respectively; P < 0.01) and microvascular/total vascular compliance ratio (86 +/- 4 vs. 68 +/- 5%, respectively; P < 0.01) increased more with BF than with Ppv. In conclusion, for a given OA-induced increase in hydraulic conductivity, BF elevation increased filtration surface area more than did Ppv elevation. The steep pulmonary pressure profile induced by increased BF could result in the recruitment of injured capillaries and could also shift downstream the compression point of blind (zone 1) and open injured vessels (zone 2).

Effect of hepatic venous sphincter contraction on transmission of central venous pressure to lobar and portal pressure.

PubMed

Lautt, W W; Legare, D J; Greenway, C V

1987-11-01

In dogs anesthetized with pentobarbital, central vena caval pressure (CVP), portal venous pressure (PVP), and intrahepatic lobar venous pressure (proximal to the hepatic venous sphincters) were measured. The objective was to determine some characteristics of the intrahepatic vascular resistance sites (proximal and distal to the hepatic venous sphincters) including testing predictions made using a recent mathematical model of distensible hepatic venous resistance. The stimulus used was a brief rise in CVP produced by transient occlusion of the thoracic vena cava in control state and when vascular resistance was elevated by infusions of norepinephrine or histamine, or by nerve stimulation. The percent transmission of the downstream pressure rise to upstream sites past areas of vascular resistance was elevated. Even small increments in CVP are partially transmitted upstream. The data are incompatible with the vascular waterfall phenomenon which predicts that venous pressure increments are not transmitted upstream until a critical pressure is overcome and then further increments would be 100% transmitted. The hepatic sphincters show the following characteristics. First, small rises in CVP are transmitted less than large elevations; as the CVP rises, the sphincters passively distend and allow a greater percent transmission upstream, thus a large rise in CVP is more fully transmitted than a small rise in CVP. Second, the amount of pressure transmission upstream is determined by the vascular resistance across which the pressure is transmitted. As nerves, norepinephrine, or histamine cause the hepatic sphincters to contract, the percent transmission becomes less and the distensibility of the sphincters is reduced. Similar characteristics are shown for the "presinusoidal" vascular resistance and the hepatic venous sphincter resistance.(ABSTRACT TRUNCATED AT 250 WORDS)

Calibration of diffuse correlation spectroscopy blood flow index with venous-occlusion diffuse optical spectroscopy in skeletal muscle

PubMed Central

Li, Zhe; Baker, Wesley B.; Parthasarathy, Ashwin B.; Ko, Tiffany S.; Wang, Detian; Schenkel, Steven; Durduran, Turgut; Li, Gang; Yodh, Arjun G.

2015-01-01

Abstract. We investigate and assess the utility of a simple scheme for continuous absolute blood flow monitoring based on diffuse correlation spectroscopy (DCS). The scheme calibrates DCS using venous-occlusion diffuse optical spectroscopy (VO-DOS) measurements of arm muscle tissue at a single time-point. A calibration coefficient (γ) for the arm is determined, permitting conversion of DCS blood flow indices to absolute blood flow units, and a study of healthy adults (N=10) is carried out to ascertain the variability of γ. The average DCS calibration coefficient for the right (i.e., dominant) arm was γ=(1.24±0.15)×108 (mL·100  mL−1·min−1)/(cm2/s). However, variability can be significant and is apparent in our site-to-site and day-to-day repeated measurements. The peak hyperemic blood flow overshoot relative to baseline resting flow was also studied following arm-cuff ischemia; excellent agreement between VO-DOS and DCS was found (R2=0.95, slope=0.94±0.07, mean difference=−0.10±0.45). Finally, we show that incorporation of subject-specific absolute optical properties significantly improves blood flow calibration accuracy. PMID:26720870

CT-Guided Superior Vena Cava Puncture: A Solution to Re-Establishing Access in Haemodialysis-Related Central Venous Occlusion Refractory to Conventional Endovascular Techniques

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

Khalifa, Mohamed, E-mail: mkhalifa@nhs.net; Patel, Neeral R., E-mail: neeral.patel06@gmail.com; Moser, Steven, E-mail: steven.moser@imperial.nhs.uk

PurposeThe purpose of this technical note is to demonstrate the novel use of CT-guided superior vena cava (SVC) puncture and subsequent tunnelled haemodialysis (HD) line placement in end-stage renal failure (ESRF) patients with central venous obstruction refractory to conventional percutaneous venoplasty (PTV) and wire transgression, thereby allowing resumption of HD.MethodsThree successive ESRF patients underwent CT-guided SVC puncture with subsequent tract recanalisation. Ultrasound-guided puncture of the right internal jugular vein was performed, the needle advanced to the patent SVC under CT guidance, with subsequent insertion of a stabilisation guidewire. Following appropriate tract angioplasty, twin-tunnelled HD catheters were inserted and HD resumed.ResultsNomore » immediate complications were identified. There was resumption of HD in all three patients with a 100 % success rate. One patient’s HD catheter remained in use for 2 years post-procedure, and another remains functional 1 year to the present day. One patient died 2 weeks after the procedure due to pancreatitis-related abdominal sepsis unrelated to the Tesio lines.ConclusionCT-guided SVC puncture and tunnelled HD line insertion in HD-related central venous occlusion (CVO) refractory to conventional recanalisation options can be performed safely, requires no extra equipment and lies within the skill set and resources of most interventional radiology departments involved in the management of HD patients.« less

[Human venous hemodynamics in microgravity and prediction of orthostatic tolerance in flight].

PubMed

Kotovskaya, A R; Fomina, G A

2013-01-01

The paper presents the results of investigating the lower limbs venous status in cosmonauts (n = 13) with the use of occlusion plethysmography in 6-month missions to the Russian segment of the International space station (ISS). An interrelation of shifts in venous capacitance, compliance and filling with orthostatic tolerance (OT) in the lower body negative pressure test (LBNP) was stated. OT predictability by the leg vein status in the course of space flight was demonstrated. The objective changes of veins predictive of OT reduction were identified. There are 3 levels of changes in venous capacitance, compliance and filling that prognosticate respective reductions in LBNP tolerance and were attested in 91% of the in-flight LBNP testing.

Risk factors, management and primary prevention of thrombotic complications related to the use of central venous catheters.

PubMed

Linnemann, Birgit; Lindhoff-Last, Edelgard

2012-09-01

An adequate vascular access is of importance for the treatment of patients with cancer and complex illnesses in the intensive, perioperative or palliative care setting. Deep vein thrombosis and thrombotic occlusion are the most common complications attributed to central venous catheters in short-term and, especially, in long-term use. In this review we will focus on the risk factors, management and prevention strategies of catheter-related thrombosis and occlusion. Due to the lack of randomised controlled trials, there is still controversy about the optimal treatment of catheter-related thrombotic complications, and therapy has been widely adopted using the evidence concerning lower extremity deep vein thrombosis. Given the increasing use of central venous catheters in patients that require long-term intravenous therapy, the problem of upper extremity deep venous thrombosis can be expected to increase in the future. We provide data for establishing a more uniform strategy for preventing, diagnosing and treating catheter-related thrombotic complications.

Radionuclide plethysmography and Tc-99m red blood cell venography in venous thrombosis: comparison with contrast venography

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

Singer, I.; Royal, H.D.; Uren, R.F.

1984-01-01

Radionuclide plethysmography (RPG) is a new technique that uses Tc-99m labelled red blood cells to ascertain changes in venous volumes by detecting the change in counts in response to the inflation and deflation of proximal thigh cuffs. Diagnosis of ileofemoral venous occlusion is possible using this technique, which also provides kinetic data of venous outflow. Twenty-one patients with suspected deep venous thrombosis were studied prospectively using RPG, radionuclide venography (RV), and contrast venography (CV) to establish the usefulness of RPG alone and in combination wth RV in the diagnosis of ileofemoral venous thrombosis (sensitivity, 91%; specificity, 100%). RV was lessmore » sensitive (73%) and less specific (93%) in diagnosing that condition.« less

Venous Access Devices: Clinical Rounds

PubMed Central

Matey, Laurl; Camp-Sorrell, Dawn

2016-01-01

Nursing management of venous access devices (VADs) requires knowledge of current evidence, as well as knowledge of when evidence is limited. Do you know which practices we do based on evidence and those that we do based on institutional history or preference? This article will present complex VAD infection and occlusion complications and some of the controversies associated with them. Important strategies for identifying these complications, troubleshooting, and evaluating the evidence related to lack of blood return, malposition, infection, access and maintenance protocols, and scope of practice issues are presented. PMID:28083553

On the relevance of "ideal" occlusion concepts for incisor inclination target definition.

PubMed

Knösel, Michael; Jung, Klaus

2011-11-01

The concept of "ideal" occlusion in harmony with craniofacial structures is often proposed as an ultimate goal of orthodontic treatment. The aim of this study was to assess the impact of slight variations in posterior occlusion and the history of straight-wire orthodontic treatment on the predictability of incisor inclination and third-order angles. Axial incisor inclinations, third-order angles, and craniofacial relationships were assessed on lateral headfilms and corresponding dental casts of 75 healthy white subjects, 16 to 26 years old, selected by the general inclusion criterion of a good interincisal relationship. Four groups were formed: group A (n = 17), Angle Class I occlusion subjects with no orthodontic treatment; group B (n = 20), Angle Class I occlusion subjects treated with standardized straight-wire orthodontics; group C (n = 20), up to a half-cusp distal occlusion after straight-wire treatment; and group D (n = 18), up to a half-cusp distal occlusion and no orthodontic treatment. Regression analysis was used to insert predictor angles into selected regression equations of the subjects with "ideal" occlusion, and the absolute differences between predicted and observed response angles were determined. Small differences in incisor inclination were found between subjects with "ideal" occlusion and those who slightly deviated from "ideal" with a mild occlusion of the Angle Class II category. Posterior occlusion was not relevant to the validity of the vast majority of predictor-response pairs. Straight-wire treatment produced incisor inclination that was slightly protruded compared with subjects who had good natural occlusion. The "ideal" posterior occlusion concepts as a general orthodontic treatment goal should be reconsidered. Copyright © 2011 American Association of Orthodontists. Published by Mosby, Inc. All rights reserved.

Ozone Gas Bath Combined with Endovenous Laser Therapy for Lower Limb Venous Ulcers: A Randomized Clinical Trial.

PubMed

Zhou, Yi-Ting; Zhao, Xu-Dong; Jiang, Jian-Wei; Li, Xin-Sheng; Wu, Zhen-Hai

2016-10-01

Endovenous laser therapy (EVLT) is safe and effective for lower limb venous ulcers. However, severe necrosis and infection in the ulcer area are contraindications of puncture and EVLT. Local bath with ozone gas has been shown to improve the condition of ulcer areas. The aim of this study was to evaluate the clinical efficacy of ozone gas bath combined with EVLT in comparison with EVLT alone for the treatment for lower limb venous ulcers. Ninety-two patients with venous ulcers were randomized to receive ozone gas bath combined with EVLT (OEVLT group) or EVLT alone (EVLT group). In the OEVLT group, the venous ulcers were preconditioned with ozone gas bath prior to EVLT. The minimum follow-up time was 12 months. The two groups were compared in terms of complete occlusion of the treated veins, ulcer healing ratio, ratio of ulcer recurrence, patient satisfaction, complications, and side effects. There was no significant difference in venous occlusion between the two groups. The ratio of ulcer healing in the OEVLT group was significantly higher than the EVLT group at 12 months follow-up. Patients in the OEVLT group showed better satisfaction and a lower recurrence ratio than the OEVLT group. No severe complications or side effects occurred in either groups. Ozone gas bath combined with EVLT showed improved efficacy for the treatment of lower limb venous ulcers and lower recurrence ratio comparison with EVLT alone. This procedure is a safe and technically feasible.

Pulmonary Veno-Occlusive Disease: A Newly Recognized Cause of Severe Pulmonary Hypertension in Dogs.

PubMed

Williams, K; Andrie, K; Cartoceti, A; French, S; Goldsmith, D; Jennings, S; Priestnall, S L; Wilson, D; Jutkowitz, A

2016-07-01

Pulmonary hypertension is a well-known though poorly characterized disease in veterinary medicine. In humans, pulmonary veno-occlusive disease (PVOD) is a rare cause of severe pulmonary hypertension with a mean survival time of 2 years without lung transplantation. Eleven adult dogs (5 males, 6 females; median age 10.5 years, representing various breeds) were examined following the development of severe respiratory signs. Lungs of affected animals were evaluated morphologically and with immunohistochemistry for alpha smooth muscle actin, desmin, CD31, CD3, CD20, and CD204. All dogs had pulmonary lesions consistent with PVOD, consisting of occlusive remodeling of small- to medium-sized pulmonary veins, foci of pulmonary capillary hemangiomatosis (PCH), and accumulation of hemosiderophages; 6 of 11 dogs had substantial pulmonary arterial medial and intimal thickening. Ultrastructural examination and immunohistochemistry showed that smooth muscle cells contributed to the venous occlusion. Increased expression of CD31 was evident in regions of PCH indicating increased numbers of endothelial cells in these foci. Spindle cells strongly expressing alpha smooth muscle actin and desmin co-localized with foci of PCH; similar cells were present but less intensely labeled elsewhere in non-PCH alveoli. B cells and macrophages, detected by immunohistochemistry, were not co-localized with the venous lesions of canine PVOD; small numbers of CD3-positive T cells were occasionally in and around the wall of remodeled veins. These findings indicate a condition in dogs with clinically severe respiratory disease and pathologic features resembling human PVOD, including foci of pulmonary venous remodeling and PCH. © The Author(s) 2016.

Venous Small Bowel Infarction: Intraoperative Laser Doppler Flowmetry Discriminates Critical Blood Supply and Spares Bowel Length

PubMed Central

Käser, S. A.; Glauser, P. M.; Maurer, C. A.

2012-01-01

Introduction. In mesenteric infarction due to arterial occlusion, laser Doppler flowmetry and spectrometry are known reliable noninvasive methods for measuring microvascular blood flow and oxygen utilisation. Case Presentation. As an innovation we used these methods in a patient with acute extensive mesenteric infarction due to venous occlusion, occurring after radical right hemicolectomy. Aiming to avoid short bowel syndrome, we spared additional 110 cm of small bowel, instead of leaving only 80 centimetres of clinically viable small bowel in situ. The pathological examination showed only 5 mm of vital mucosa to be left distal to the dissection margin. No further interventions were necessary. Conclusion. Laser doppler flowmetry and spectrometry are potentially powerful methods to assist the surgeon's decision-making in critical venous mesenteric perfusion, thus having an important impact on clinical outcome. PMID:23093968

[Controlled study of increasing venous tone in primary varicose veins by oral administration of Ruscus aculeatus and trimethylhespiridinchalcone].

PubMed

Weindorf, N; Schultz-Ehrenburg, U

1987-01-01

In a randomized double blind study, 50 patients suffering from trunk or branch varicosis were orally treated with either a commercial preparation of Ruscus extract, trimethyl hesperidine chalcone and ascorbic acid (Phlebodril), or a placebo over 2 weeks. Changes of the venous tonus were measured by means of venous occlusion plethysmography in rest position (venous capacity, venous distensibility) as well as during (active) exercise (expelled blood volume). All parameters showed a tendency towards improvement in the verum group. The changes were partly significant (p less than 0.5). The course of the study suggests that the period of treatment possibly was too short to obtain the full pharmacologic effect.

Central retinal vein occlusion with cilioretinal infarction from branch flow exclusion and choroidal arterial steal.

PubMed

McLeod, David

2009-01-01

The first definitive study of retinal vein occlusion complicated by infarction within the territory of one or more cilioretinal arteries was published in 1976. Many individual cases and further case series have been reported in the interim, but the nature of the interrelationship is still under debate. A review was undertaken of the relevant clinical and fundus fluorescein angiographic characteristics of this combined retinal vascular disorder together with the pathophysiological mechanisms currently presented in the literature to explain their association. Scientific publications up to 2008 were evaluated by one of the authors of the original report. There are broad similarities between publications in their descriptions of the clinical features, but significant differences of detail and interpretation are also evident. Most of the mechanisms so far proposed to account for cilioretinal infarction after central or hemisphere retinal vein occlusion do not withstand critical scrutiny. Two related hypotheses are expounded that appear to satisfactorily elucidate this interrelationship -- branch flow exclusion and branch flow diversion (otherwise termed "choroidal arterial steal"). In eyes with a cilioretinal supply, the probability that cilioretinal infarction will complicate retinal vein occlusion increases with increasing severity of venous obstruction and the more distally the cilioretinal artery arises from the posterior ciliary arterial tree. A distal branch point also facilitates observation of dye front reciprocation within the artery. Indicators of the degree of venous obstruction that may be necessary to instigate cilioretinal infarction include very prolonged dye transit times in the central retinal circulation, exaggerated venous cyanosis and tortuosity, perivenous cotton-wool sentinels, and macular perivenular whitening.

von Willebrand factor and factor VIII are independently required to form stable occlusive thrombi in injured veins

PubMed Central

Chauhan, Anil K.; Kisucka, Janka; Lamb, Colin B.; Bergmeier, Wolfgang

2007-01-01

von Willebrand factor (VWF) protects factor VIII (FVIII) from proteolysis and mediates the initial contact of platelets with the injured vessel wall, thus playing an important role in hemostasis and thrombosis. VWF is crucial for the formation of occlusive thrombi at arterial shear rates. However, with only a few conflicting studies published, the role of VWF in venous thrombosis is still unclear. Using gene-targeted mice, we show that in ferric chloride–injured veins platelet adhesion to subendothelium is decreased and thrombus growth is impaired in VWF−/− mice when compared with wild type (WT). We also observed increased embolization in the VWF−/− mice, which was due to lower FVIII levels in these mice as recombinant factor VIII (r-FVIII) restored thrombus stability. Despite normalization of blood clotting time and thrombus stability after r-FVIII infusion, the VWF−/− venules did not occlude. Transgenic platelets lacking the VWF receptor GPIbα extracellular domain showed decreased adhesion to injured veins. But, after a delay, all the injured venules occluded in these transgenic mice. Thus, VWF likely uses other adhesion receptors besides GPIbα in thrombus growth under venous shear conditions. Our studies document crucial roles for VWF and FVIII in experimental thrombosis under venous flow conditions in vivo. PMID:17119108

Thrombotic complications of implanted central venous access devices: prospective evaluation.

PubMed

Labourey, Jean-Luc; Lacroix, Philippe; Genet, Dominique; Gobeaux, François; Martin, Jean; Venat-Bouvet, Laurence; Lavau-Denes, Sandrine; Maubon, Antoine; Tubiana-Mathieu, Nicole

2004-05-01

Implanted venous access devices (IVAD) are routinely used in oncologic patients. Thrombotic complication is a source of morbidity. During one year 246 patients with different solid neoplastic diseases received IVAD for chemotherapy administration. Two hundred forty-nine IVAD were placed percutaneously or by surgical cutdown. IVAD were flushed immediately after implantation with 3-5 mL of heparinized saline (100 U/mL). No monthly flush was required. A prospective evaluation of thrombotic complications was realised. in event of catheter dysfunction and/or clinical symptoms of phlebitis, a catheter opacification and/or a Doppler ultrasonography were performed. Twenty-three catheter dysfunctions were noted, corresponding to 13 catheter occlusions. Twelve patients presented clinical symptoms of phlebitis. Eleven venous thrombosis were diagnosed in this group; 10 by echo-Doppler and one by scanography. A unvaried statistic analysis using Fisher's test was performed to detect risk factors. Two factors were identified: the position of catheter tip above T4 (p < 0.001) and mediastinal or cervical lymph nodes larger than 6 cm (p < 0.001). The first increased the risk of catheter occlusion and the second increased the risk of phlebitis.

Endovascular Stent Treatment for Symptomatic Benign Iliofemoral Venous Occlusive Disease: Long-Term Results 1987-2009

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

Gutzeit, A., E-mail: andreas.gutzeit@ksw.ch; Zollikofer, Ch. L., E-mail: Christoph.Zollikofer@ksb.ch; Dettling-Pizzolato, M., E-mail: Mira.Dettling@ksw.ch

Venous stenting has been shown to effectively treat iliofemoral venous obstruction with good short- and mid-term results. The aim of this study was to investigate long-term clinical outcome and stent patency. Twenty patients were treated with venous stenting for benign disease at our institution between 1987 and 2005. Fifteen of 20 patients (15 female, mean age at time of stent implantation 38 years [range 18-66]) returned for a clinical visit, a plain X-ray of the stent, and a Duplex ultrasound. Four patients were lost to follow-up, and one patient died 277 months after stent placement although a good clinical resultmore » was documented 267 months after stent placement. Mean follow-up after stent placement was 167.8 months (13.9 years) (range 71 (6 years) to 267 months [22 years]). No patient needed an additional venous intervention after stent implantation. No significant difference between the circumference of the thigh on the stented side (mean 55.1 cm [range 47.0-70.0]) compared with the contralateral thigh (mean 54.9 cm [range 47.0-70.0]) (p = 0.684) was seen. There was a nonsignificant trend toward higher flow velocities within the stent (mean 30.8 cm/s [range 10.0-48.0]) and the corresponding vein segment on the contralateral side (mean 25.2 cm/s [range 12.0-47.0]) (p = 0.065). Stent integrity was confirmed in 14 of 15 cases. Only one stent showed a fracture, as documented on x-ray, without any impairment of flow. Venous stenting using Wallstents showed excellent long-term clinical outcome and primary patency rate.« less

Sharp Central Venous Recanalization in Hemodialysis Patients: A Single-Institution Experience

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

Arabi, Mohammad, E-mail: marabi2004@hotmail.com; Ahmed, Ishtiaq; Mat’hami, Abdulaziz

PurposeWe report our institutional experience with sharp central venous recanalization in chronic hemodialysis patients who failed standard techniques.Materials and MethodsSince January 2014, a series of seven consecutive patients (four males and three females), mean age 35 years (18–65 years), underwent sharp central venous recanalization. Indications included obtaining hemodialysis access (n = 6) and restoration of superior vena cava (SVC) patency to alleviate occlusion symptoms and restore fistula function (n = 1). The transseptal needle was used for sharp recanalization in six patients, while it could not be introduced in one patient due to total occlusion of the inferior vena cava. Instead, transmediastinal SVC access using Chibamore » needle was obtained.ResultsTechnical success was achieved in all cases. SVC recanalization achieved symptoms’ relief and restored fistula function in the symptomatic patient. One patient underwent arteriovenous fistula creation on the recanalized side 3 months after the procedure. The remaining catheters were functional at median follow-up time of 9 months (1–14 months). Two major complications occurred including a right hemothorax and a small hemopericardium, which were managed by covered stent placement across the perforated SVC.ConclusionSharp central venous recanalization using the transseptal needle is feasible technique in patients who failed standard recanalization procedures. The potential high risk of complications necessitates thorough awareness of anatomy and proper technical preparedness.« less

Incidence and Determinants of Port Occlusions in Cancer Outpatients: A Prospective Cohort Study.

PubMed

Milani, Alessandra; Mazzocco, Ketti; Gandini, Sara; Pravettoni, Gabriella; Libutti, Livio; Zencovich, Claudia; Sbriglia, Ada; Pari, Chiara; Magon, Giorgio; Saiani, Luisa

Normal saline is considered a safe alternative for heparin as a locking solution in totally implantable venous access devices. The incidence rate of partial occlusion with the use of normal saline (easy injection, impossible aspiration) is estimated at 4%. The aim of this study was to investigate determinants of partial occlusions with the use of normal saline solution and the maintenance of positive pressure in the catheter. We enrolled 218 patients with different solid tumors who underwent pharmacologic treatment through the port with different frequencies: from once every week to at least once every month. The port was flushed with normal saline solution keeping a positive pressure in the catheter. We performed 4111 observations and documented normal port functioning in 99% of observations (n = 4057) and partial occlusions in 1% of observations (n = 54). Partial occlusions were significantly associated with frequency of port flushing (P < .05), chemotherapy (P < .001), and blood sample collection (P < .001). The use of positive pressure in addition to normal saline reduces the incidence rate of partial occlusions. The type of treatment, blood sample collection, and treatment schedule are important determinants of partial occlusions. Nurses play a key role in maintaining a functioning port using positive pressure during the flushing techniques. Certain risk factors must be monitored to prevent partial occlusions, and certain patients are more likely to present with port-related problems.

Radionuclide plethysmography and Tc-99m red blood cell venography in venous thrombosis: comparison with contrast venography

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

Singer, I.; Royal, H.D.; Uren, R.F.

1984-01-01

Radionuclide plethysmography (RPG) is a new technique that uses Tc-99m labelled red blood cells to ascertain changes in venous volumes by detecting the change in counts in response to the inflation and deflation of proximal thigh cuffs. Diagnosis of ileofemoral venous occlusion is possible using this technique, which also provides kinetic data of venous outflow. A range of normal values was defined in 19 subjects for per cent change in venous capacitance and venous outflow. Twenty-one patients with suspected deep venous thrombosis were studied prospectively using RPG, radionuclide venography (RV), and contrast venography (CV) to establish the usefulness of RPGmore » alone and in combination with RV in the diagnosis of deep venous thrombosis. RPG proved to be a reliable technique for the diagnosis of ileofemoral venous thrombosis (sensitivity, 91%; specificity, 100%). RV was less sensitive (73%) and less specific (93%) in diagnosing that condition. When RPG is used as the criterion for the detection of ileofemoral vein thrombosis and RV is used as the criterion for the detection of calf vein thrombosis, the combined techniques show improved sensitivity (92%) and specificity (93%) for the detection of all deep venous thromboses.« less

The effect of peripherally inserted central catheter (PICC) valve technology on catheter occlusion rates--the 'ELeCTRiC' study.

PubMed

Johnston, Andrew J; Streater, Carmel T; Noorani, Remy; Crofts, Joanne L; Del Mundo, Aldwin B; Parker, Richard A

2012-01-01

Peripherally Inserted Central Catheters (PICCs) are increasingly being used to provide short to medium-term central venous access. The current study was designed to test the hypothesis that PICC valve technology does not influence PICC occlusion rates. Intensive care unit (ICU) patients who required a PICC were randomized to one of three types of dual lumen PICC (open ended non-valved, Groshong valve, PASV valve). PICC occlusions were recorded and managed with a protocol that used urokinase. A total of 102 patients were recruited to the study. The overall risk of occlusion per catheter was 35% (95% CI 26% to 44%). The overall rate of occlusion was 76 occlusions per 1000 catheter days (95% CI 61 to 95). Presence or type of valve did not significantly influence this rate (open-ended non-valved PICC 38% of catheters, 79 occlusions per 1000 catheter days; Groshong 38% of catheters, 60 occlusions per 1000 catheter days; PASV 27% of catheters, 99 occlusions per 1000 catheter days). The dose of urokinase required to treat PICC occlusions did not significantly differ between PICC types. Valved PICCs do not appear to influence PICC occlusion rates.

Use of peripherally inserted central venous catheters (PICCs) in children receiving autologous or allogeneic stem-cell transplantation.

PubMed

Benvenuti, Stefano; Ceresoli, Rosanna; Boroni, Giovanni; Parolini, Filippo; Porta, Fulvio; Alberti, Daniele

2018-03-01

The aim of our study was to present our experience with the use of peripherally inserted central catheters (PICCs) in pediatric patients receiving autologous or allogenic blood stem-cell transplantation. The insertion of the device in older children does not require general anesthesia and does not require a surgical procedure. From January 2014 to January 2017, 13 PICCs were inserted as a central venous device in 11 pediatric patients submitted to 14 autologous or allogeneic stem-cell transplantation, at the Bone Marrow Transplant Unit of the Children's Hospital of Brescia. The mean age of patients at the time of the procedure was 11.3 years (range 3-18 years). PICCs remained in place for an overall period of 4104 days. All PICCs were positioned by the same specifically trained physician and utilized by nurses of our stem-cell transplant unit. No insertion-related complications were observed. Late complications were catheter ruptures and line occlusions (1.2 per 1000 PICC days). No rupture or occlusion required removal of the device. No catheter-related venous thrombosis, catheter-related bloodstream infection (CRBSI), accidental removal or permanent lumen occlusion were observed. Indications for catheter removal were completion of therapy (8 patients) and death (2 patients). Three PICCs are currently being used for blood sampling in follow-up patients after transplantation. Our data suggest that PICCs are a safe and effective alternative to conventional central venous catheters even in pediatric patients with high risk of infectious and hemorrhagic complications such as patients receiving stem-cell transplantation.

Disulfide HMGB1 derived from platelets coordinates venous thrombosis in mice

PubMed Central

Philippi, Vanessa; Stockhausen, Sven; Busse, Johanna; Antonelli, Antonella; Miller, Meike; Schubert, Irene; Hoseinpour, Parandis; Chandraratne, Sue; von Brühl, Marie-Luise; Gaertner, Florian; Lorenz, Michael; Agresti, Alessandra; Coletti, Raffaele; Antoine, Daniel J.; Heermann, Ralf; Jung, Kirsten; Reese, Sven; Laitinen, Iina; Schwaiger, Markus; Walch, Axel; Sperandio, Markus; Nawroth, Peter P.; Reinhardt, Christoph; Jäckel, Sven; Bianchi, Marco E.; Massberg, Steffen

2016-01-01

Deep venous thrombosis (DVT) is one of the most common cardiovascular diseases, but its pathophysiology remains incompletely understood. Although sterile inflammation has recently been shown to boost coagulation during DVT, the underlying molecular mechanisms are not fully resolved, which could potentially identify new anti-inflammatory approaches to prophylaxis and therapy of DVT. Using a mouse model of venous thrombosis induced by flow reduction in the vena cava inferior, we identified blood-derived high-mobility group box 1 protein (HMGB1), a prototypical mediator of sterile inflammation, to be a master regulator of the prothrombotic cascade involving platelets and myeloid leukocytes fostering occlusive DVT formation. Transfer of platelets into Hmgb1−/− chimeras showed that this cell type is the major source of HMGB1, exposing reduced HMGB1 on their surface upon activation thereby enhancing the recruitment of monocytes. Activated leukocytes in turn support oxidation of HMGB1 unleashing its prothrombotic activity and promoting platelet aggregation. This potentiates the amount of HMGB1 and further nurtures the accumulation and activation of monocytes through receptor for advanced glycation end products (RAGE) and Toll-like receptor 2, leading to local delivery of monocyte-derived tissue factor and cytokines. Moreover, disulfide HMGB1 facilitates formation of prothrombotic neutrophil extracellular traps (NETs) mediated by RAGE, exposing additional HMGB1 on their extracellular DNA strands. Eventually, a vicious circle of coagulation and inflammation is set in motion leading to obstructive DVT formation. Therefore, platelet-derived disulfide HMGB1 is a central mediator of the sterile inflammatory process in venous thrombosis and could be an attractive target for an anti-inflammatory approach for DVT prophylaxis. PMID:27574188

Liver size, bodyweight, and tolerance to acute complete occlusion of congenital extrahepatic portosystemic shunts in dogs.

PubMed

Doran, Ivan P; Barr, Frances J; Hotston Moore, Alasdair; Knowles, Toby G; Holt, Peter E

2008-10-01

To investigate the relationship between preoperative liver size, bodyweight, and tolerance to shunt occlusion in dogs with congenital extrahepatic portosystemic shunt(s) (CPSS). Longitudinal cohort study. Dogs with CPSS (n=35). Ultrasonography was used to measure preoperative maximum transverse dimension of the liver (TS) of each dog. Intraoperative portal pressures were measured, before and after CPSS occlusion, via a jejunal vein catheter. Tolerance to shunt occlusion was judged on gross visceral observations, and on changes in portal pressure, central venous and mean arterial pressures. TS was significantly related to bodyweight (P<.05). Mean ratios for TS/bodyweight were calculated for dogs tolerant and intolerant of acute complete shunt occlusion. Dogs tolerant to occlusion had significantly higher TS/bodyweight ratios than dogs intolerant to occlusion (P=.025). Dogs with a TS/bodyweight ratio of >7 were more likely to tolerate CPSS occlusion than dogs with a TS/bodyweight ratio of <5 (P=.036). A model was generated to predict portal pressure rise after shunt occlusion, based on liver dimensions and bodyweight (R=0.668). Intestinal oxygenation did not correlate significantly with tolerance to CPSS occlusion (P=.29). In dogs with CPSS, liver size (relative to bodyweight) is significantly greater (P=.025) in dogs that are tolerant of full ligation than intolerant of occlusion. Preoperative measurement of bodyweight and liver size help indicate the likelihood of tolerance to acute complete occlusion of CPSS in dogs.

Discriminative correlation filter tracking with occlusion detection

NASA Astrophysics Data System (ADS)

Zhang, Shuo; Chen, Zhong; Yu, XiPeng; Zhang, Ting; He, Jing

2018-03-01

Aiming at the problem that the correlation filter-based tracking algorithm can not track the target of severe occlusion, a target re-detection mechanism is proposed. First of all, based on the ECO, we propose the multi-peak detection model and the response value to distinguish the occlusion and deformation in the target tracking, which improve the success rate of tracking. And then we add the confidence model to update the mechanism to effectively prevent the model offset problem which due to similar targets or background during the tracking process. Finally, the redetection mechanism of the target is added, and the relocation is performed after the target is lost, which increases the accuracy of the target positioning. The experimental results demonstrate that the proposed tracker performs favorably against state-of-the-art methods in terms of robustness and accuracy.

Evaluation of the need for chest X-rays in the management of asymptomatic, intraluminal vascular access device occlusion in childhood cancer.

PubMed

Stammers, David; Connolly, Bairbre; Brandão, Leonardo R; Zupanec, Sue; Gupta, Sumit

2017-07-01

Venous access device (VAD) occlusion from intraluminal thrombus is a common complication during childhood cancer treatment. Current practice at many institutions is to assess VAD position with a chest X-ray (CXR) prior to intraluminal administration of tissue plasminogen activator (tPA). We aimed to determine the utility of this practice. A retrospective chart review of children with newly diagnosed cancer with a VAD, treated at The Hospital for Sick Children between 2010 and 2011, was performed. Episodes of line occlusion were identified both by reviewing patient CXRs for indication and identifying tPA doses dispensed. These episodes were reviewed to determine whether CXR findings resulted in management other than tPA. Cases in which the X-ray resulted in a change in management were further reviewed to determine whether administration of tPA could have resulted in potential patient harm. A total of 330 patients with newly diagnosed cancer with VADs were identified. Eighty-five (25.8%) patients experienced 123 episodes of VAD occlusion. VAD occlusions occurred more frequently in patients with tunneled external central venous lines (16/39, 41.5%) and peripherally inserted central catheters (PICC) (27/73, 37.0%) versus PORT (42/216, 19.4%; P = 0.001). There were nine (8.1%) episodes of VAD occlusion evaluated with a CXR in which the findings led to a change in management other than administering tPA. In each case, multiple specialists independently concluded that administration of tPA would have been unlikely to cause patient harm. Routine CXRs prior to the administration of tPA for asymptomatic VAD occlusion can safely be omitted. © 2016 Wiley Periodicals, Inc.

A pilot study and novel angiographic classification for superior sagittal sinus stenting in patients with non-thrombotic intracranial venous occlusive disease.

PubMed

Raper, Daniel M S; Buell, Thomas J; Ding, Dale; Pomeraniec, I Jonathan; Crowley, R Webster; Liu, Kenneth C

2018-01-01

Safety and efficacy of superior sagittal sinus (SSS) stenting for non-thrombotic intracranial venous occlusive disease (VOD) is unknown. The aim of this retrospective cohort study is to evaluate outcomes after SSS stenting. We evaluated an institutional database to identify patients who underwent SSS stenting. Radiographic and clinical outcomes were analyzed and a novel angiographic classification of the SSS was proposed. We identified 19 patients; 42% developed SSS stenosis after transverse sinus stenting. Pre-stent maximum mean venous pressure (MVP) in the SSS of 16.2 mm Hg decreased to 13.1 mm Hg after stenting (p=0.037). Preoperative trans-stenosis pressure gradient of 4.2 mm Hg decreased to 1.5 mm Hg after stenting (p<0.001). No intraprocedural complication or junctional SSS stenosis distal to the stent construct was noted. Improvement in headache, tinnitus, and visual obscurations was reported by 66.7%, 63.6%, and 50% of affected patients, respectively, at mean follow-up of 5.2 months. We divided the SSS into four anatomically equal segments, numbered S1-S4, from the torcula to frontal pole. SSS stenosis typically occurs in the S1 segment, and the anterior extent of SSS stents was deployed at the S1-S2 junction in all but one case. SSS stenting is reasonably safe, may improve clinical symptoms, and significantly reduces maximum MVP and trans-stenosis pressure gradients in patients with VOD with SSS stenosis. The S1 segment is most commonly stenotic, and minimum pressure gradients for symptomatic SSS stenosis may be lower than for transverse or sigmoid stenosis. Additional studies and follow-up are necessary to better elucidate appropriate clinical indications and long-term efficacy of SSS stenting. 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/.

Lower body positive pressure application with an antigravity suit in acute carotid occlusion.

PubMed

Berthet, Karine; Lukaszewicz, Anne Claire; Bousser, Marie-Germaine; Payen, Didier

2010-04-01

The challenge in acute stroke is still to reperfuse as early as possible the ischemic territory. Since fibrinolytic therapies have a limited window with potential risk of bleeding, having a nonpharmacologic mean to recruit vessels in area surrounding necrosis might be useful. We propose here to use antigravity suit inflated at "venous" pressure levels to shift blood towards thoracic and brain territories. We report two cases of spectacular clinical recovery after acute carotid occlusion.

Effect of PEEP, blood volume, and inspiratory hold maneuvers on venous return.

PubMed

Berger, David; Moller, Per W; Weber, Alberto; Bloch, Andreas; Bloechlinger, Stefan; Haenggi, Matthias; Sondergaard, Soren; Jakob, Stephan M; Magder, Sheldon; Takala, Jukka

2016-09-01

According to Guyton's model of circulation, mean systemic filling pressure (MSFP), right atrial pressure (RAP), and resistance to venous return (RVR) determine venous return. MSFP has been estimated from inspiratory hold-induced changes in RAP and blood flow. We studied the effect of positive end-expiratory pressure (PEEP) and blood volume on venous return and MSFP in pigs. MSFP was measured by balloon occlusion of the right atrium (MSFPRAO), and the MSFP obtained via extrapolation of pressure-flow relationships with airway occlusion (MSFPinsp_hold) was extrapolated from RAP/pulmonary artery flow (QPA) relationships during inspiratory holds at PEEP 5 and 10 cmH2O, after bleeding, and in hypervolemia. MSFPRAO increased with PEEP [PEEP 5, 12.9 (SD 2.5) mmHg; PEEP 10, 14.0 (SD 2.6) mmHg, P = 0.002] without change in QPA [2.75 (SD 0.43) vs. 2.56 (SD 0.45) l/min, P = 0.094]. MSFPRAO decreased after bleeding and increased in hypervolemia [10.8 (SD 2.2) and 16.4 (SD 3.0) mmHg, respectively, P < 0.001], with parallel changes in QPA Neither PEEP nor volume state altered RVR (P = 0.489). MSFPinsp_hold overestimated MSFPRAO [16.5 (SD 5.8) vs. 13.6 (SD 3.2) mmHg, P = 0.001; mean difference 3.0 (SD 5.1) mmHg]. Inspiratory holds shifted the RAP/QPA relationship rightward in euvolemia because inferior vena cava flow (QIVC) recovered early after an inspiratory hold nadir. The QIVC nadir was lowest after bleeding [36% (SD 24%) of preinspiratory hold at 15 cmH2O inspiratory pressure], and the QIVC recovery was most complete at the lowest inspiratory pressures independent of volume state [range from 80% (SD 7%) after bleeding to 103% (SD 8%) at PEEP 10 cmH2O of QIVC before inspiratory hold]. The QIVC recovery thus defends venous return, possibly via hepatosplanchnic vascular waterfall. Copyright © 2016 the American Physiological Society.

Veno occlusive disease: Update on clinical management

PubMed Central

Senzolo, M; Germani, G; Cholongitas, E; Burra, P; Burroughs, AK

2007-01-01

Hepatic veno-occlusive disease is a clinical syndrome characterized by hepatomegaly, ascites, weight gain and jaundice, due to sinusoidal congestion which can be caused by alkaloid ingestion, but the most frequent cause is haematopoietic stem cell transplantation (STC) and is also seen after solid organ transplantation. The incidence of veno occlusive disease (VOD) after STC ranges from 0 to 70%, but is decreasing. Survival is good when VOD is a mild form, but when it is severe and associated with an increase of hepatic venous pressure gradient > 20 mmHg, and mortality is about 90%. Prevention remains the best therapeutic strategy, by using non-myeloablative conditioning regimens before STC. Prophylactic administration of ursodeoxycholic acid, being an antioxidant and antiapoptotic agent, can have some benefit in reducing overall mortality. Defibrotide, which has pro-fibrinolytic and antithrombotic properties, is the most effective therapy; decompression of the sinusoids by a transjugular intrahepatic portosystemic shunt (TIPS) can be tried, especially to treat VOD after liver transplantation and when multiorgan failure (MOF) is not present. Liver transplantation can be the last option, but can not be considered a standard rescue therapy, because usually the concomitant presence of multiorgan failure contraindicates this procedure. PMID:17663504

[Effects of lidocaine on arterial and venous circulation of limbs in man].

PubMed

Edouard, A; Probst, D; Duranteau, J; Tarot, J P; Pussard, E

1991-01-01

The effects of intravenous lidocaine on limb arteries and veins were investigated in a placebo-controlled study. Seven young healthy volunteers, 23 to 28-years-old, were included. Electrocardiogram, arterial pressure and arm and leg blood flows were recorded continuously. Systolic and diastolic blood pressures were measured in the left arm by finger photoplethysmography. Limb blood flow and the limb venous system were studied by venous occlusive plethysmography. The venous parameters studied were venous tone, lowest closing pressure, venous volume at 30 mmHg, and venous distensibility. After an initial bolus of 1.5 mg.kg-1 lidocaine had been given, 30, and then 60, micrograms.kg-1.min-1 were given for one hour each. Plasma noradrenaline and serum lidocaine titres were measured before giving the lidocaine, and at the end of each one hour period. Placebo consisted in a two hour infusion of 0.25 ml.min-1 normal saline. Lidocaine titres were 1.64 +/- 0.40 microgram.ml-1 after one hour, and 2.55 +/- 0.69 microgram.ml-1 after two hours. Lidocaine increased vascular resistances in both the forearm (+81% to +93%) and the calf (+38% to +57%). There was a concomitant increase in mean arterial blood pressure (+21% to +28%) without any change in heart rate. There was a significant dose-dependent increase in plasma noradrenaline levels during the second period of the lidocaine infusion with respect to the preinfusion period and the same period during the placebo infusion. Venous capacitance measured before any infusion had been started was greater in the leg than in the arm.(ABSTRACT TRUNCATED AT 250 WORDS)

Clinical management of renal cell carcinoma with venous tumor thrombus.

PubMed

Agochukwu, Nnenaya; Shuch, Brian

2014-06-01

Venous invasion is common in advanced renal cell carcinoma (RCC) due to the unique biology of this cancer. The presence of a tumor thrombus often makes clinical management challenging. In this review, we detail specific preoperative, perioperative, and surgical strategies involving the care of the complex kidney cancer patient with venous tumor involvement. We performed a comprehensive review of selected peer-reviewed publications regarding RCC tumor thrombus biology, medical and surgical management techniques, and immediate and long-term outcomes. The perioperative management may require special imaging techniques, preoperative testing, very recent imaging, and consultation with other surgical services. There are various approaches to these patients as the clinical presentation, stage of disease, primary tumor size, level of thrombus, degree of venous occlusion, presence of bland thrombus, and primary tumor laterality influence management. Select patients with metastatic disease can do well with cytoreductive nephrectomy and thrombectomy. Those with localized disease have a high risk of recurrence; however, some patients can exhibit durable survival with surgery alone. The evolving surgical and medical treatments are discussed. Even when these surgeries are performed in high volume centers, significant perioperative complications are common and greater complications are seen with higher thrombus extent. If surgery is attempted, it is important for urologic oncologists to follow strict attention to specific surgical principles. These general principles include complete vascular control, avoidance of thrombus embolization, close hemodynamic monitoring, and institutional resources for caval resection/replacement and venous bypass if necessary.

Swine Model of Thrombotic Caval Occlusion Created by Autologous Thrombus Injection with Assistance of Intra-caval Net Knitting

PubMed Central

Shi, Wan-Yin; Wu, Shuang; Hu, Lan-Yue; Liu, Chang-Jian; Gu, Jian-Ping

2015-01-01

To evaluate the feasibility of a swine model of thrombotic inferior vena cava (IVC) occlusion (IVCO) created by autologous thrombus injection with assistance of intra-caval net knitting. Sixteen pigs were included and divided into two groups: Group A (n = 10), IVCO model created by knitting a caval net followed by autologous thrombus injection; Group B (n = 6), control model created by knitting a net and normal saline injection. Venography was performed to assess each model and the associated thrombotic occlusion. The vessels were examined histologically to analyse the pathological changes postoperatively. IVCO model was successfully created in 10 animals in Group A (100%). Immediate venography showed extensive clot burden in the IVC. Postoperative venography revealed partial caval occlusion at 7 days, and complete occlusion coupled with collateral vessels at 14 days. Histologically, Group A animals had significantly greater venous wall thickening, with CD163-positive and CD3-positive cell infiltration. Recanalization channels were observed at the margins of the thrombus. By contrast, no thrombotic occlusion of the IVC was observed in Group B. The thrombotic IVCO model can be reliably established in swine. The inflammatory reaction may contribute to the caval thrombus propagation following occlusion. PMID:26680253

Improved methods for venous access: the Port-A-Cath, a totally implanted catheter system.

PubMed

Strum, S; McDermed, J; Korn, A; Joseph, C

1986-04-01

We prospectively evaluated the performance and rate of long-term complications with the Port-A-Cath (PAC), a totally implanted vascular access system. Two catheter styles were evaluated, a small-bore (SB) catheter (0.51-mm diameter) and a large-bore (LB) catheter (1.02-mm diameter), in conjunction with the use of a strict catheter care protocol. The PAC performed well, and with both SB and LB systems, no significant extravasation, skin necrosis, hematoma, septum damage or leakage, or subcutaneous portal infections occurred after 7,240 days of implantation and 1,435 days of use. Complications with the PAC system consisted of catheter occlusion (seven patients, 21.5%) and one instance of possible catheter infection (3.1%). Occlusions were limited to patients implanted with the SB catheter (seven of 16, 43.8%), and five of the seven (71.4%) occurred in patients receiving continuous infusion chemotherapy and/or total parenteral nutrition. Patency of the PAC system was maintained using a regular flushing schedule once every 30 days, a significant advantage compared with the daily maintenance schedule required with externally placed venous catheters. The results of this study suggest that the PAC system can provide a safe and reliable method for venous access in patients requiring intermittent or prolonged intravenous therapy.

[Relationship between Occlusal Discomfort Syndrome and Occlusal Threshold].

PubMed

Munakata, Motohiro; Ono, Yumie; Hayama, Rika; Kataoka, Kanako; Ikuta, Ryuhei; Tamaki, Katsushi

2016-03-01

Occlusal dysesthesia has been defined as persistent uncomfortable feelings of intercuspal position continuing for more than 6 months without evidence of physical occlusal discrepancy. The problem often occurs after occlusal intervention by dental care. Although various dental treatments (e. g. occlusal adjustment, orthodontic treatment and prosthetic reconstruction) are attempted to solve occlusal dysesthesia, they rarely reach a satisfactory result, neither for patients nor dentists. In Japan, these symptoms are defined by the term "Occlusal discomfort syndrome" (ODS). The aim of this study was to investigate the characteristics of ODS with the simple occlusal sensory perceptive and discriminative test. Twenty-one female dental patients with ODS (mean age 55.8 ± 19.2 years) and 21 age- and gender-matched dental patients without ODS (mean age 53.1 ± 16.8 years) participated in the study. Upon grinding occlusal registration foils that were stacked to different thicknesses, participants reported the thicknesses at which they recognized the foils (recognition threshold) and felt discomfort (discomfort threshold). Although there was no significant difference in occlusal recognition thresholds between the two patient groups, the discomfort threshold was significantly smaller in the patients with ODS than in those without ODS. Moreover, the recognition threshold showed an age-dependent increase in patients without ODS, whereas it remained comparable between the younger (< 60 years old) and elderly (60 years old or more) patient subgroups with ODS. These results suggest that occlusal discomfort threshold rather than recognition threshold is an issue in ODS. The foil grinding procedure is a simple and useful method to evaluate occlusal perceptive and discriminative abilities in patients with ODS.

Does partial occlusion promote normal binocular function?

PubMed

Li, Jingrong; Thompson, Benjamin; Ding, Zhaofeng; Chan, Lily Y L; Chen, Xiang; Yu, Minbin; Deng, Daming; Hess, Robert F

2012-10-03

There is growing evidence that abnormal binocular interactions play a key role in the amblyopia syndrome and represent a viable target for treatment interventions. In this context the use of partial occlusion using optical devices such as Bangerter filters as an alternative to complete occlusion is of particular interest. The aims of this study were to understand why Bangerter filters do not result in improved binocular outcomes compared to complete occlusion, and to compare the effects of Bangerter filters, optical blur and neutral density (ND) filters on normal binocular function. The effects of four strengths of Bangerter filters (0.8, 0.6, 0.4, 0.2) on letter and vernier acuity, contrast sensitivity, stereoacuity, and interocular suppression were measured in 21 observers with normal vision. In a subset of 14 observers, the partial occlusion effects of Bangerter filters, ND filters and plus lenses on stereopsis and interocular suppression were compared. Bangerter filters did not have graded effect on vision and induced significant disruption to binocular function. This disruption was greater than that of monocular defocus but weaker than that of ND filters. The effect of the Bangerter filters on stereopsis was more pronounced than their effect on monocular acuity, and the induced monocular acuity deficits did not predict the induced deficits in stereopsis. Bangerter filters appear to be particularly disruptive to binocular function. Other interventions, such as optical defocus and those employing computer generated dichoptic stimulus presentation, may be more appropriate than partial occlusion for targeting binocular function during amblyopia treatment.

Popliteal Venous Aneurysm: A Rare Cause of Recurrent Pulmonary Emboli and Limb Swelling

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

Russell, David A., E-mail: davearussell@aol.com; Robinson, Graham J.; Johnson, Brian F.

2008-09-15

Popliteal venous aneurysm is a rare cause of recurrent pulmonary embolism, although the true incidence of aneurysm is probably underestimated. One-third of patients suffer further embolic events despite therapeutic anticoagulation. We report the case of a 59-year-old male who presented with recurrent PEs over a period of 12 years despite anticoagulation therapy. A thrombophilia screen and abdominal ultrasound were normal at that time. He reattended with recurrent pulmonary emboli, left calf swelling, and a mass in his left popliteal fossa causing limitation of knee movement. Venous duplex and MRI of his popliteal fossa demonstrated a thrombosed true popliteal venous aneurysmmore » with popliteal and superficial femoral vein occlusion. In view of the mass effect we proceeded to surgical excision of his aneurysm after prophylactic placement of an IVC filter. The patient regained normal knee function with intensive inpatient physiotherapy. He has been recommenced on lifelong anticoagulant. The presentation, investigation, and management of the condition are briefly discussed. We suggest that a bilateral lower limb duplex is performed to exclude venous aneurysm in all patients presenting with pulmonary embolism in which an underlying source cannot otherwise be identified and no thrombophilic tendency is detected.« less

Portal Vein Stenting for Delayed Jejunal Varix Bleeding Associated with Portal Venous Occlusion after Hepatobiliary and Pancreatic Surgery

PubMed Central

Hyun, Dongho; Cho, Sung Ki; Park, Hong Suk; Shin, Sung Wook; Choo, Sung Wook; Do, Young Soo; Choo, In Wook; Choi, Dong Wook

2017-01-01

Objective The study aimed to describe portal stenting for postoperative portal occlusion with delayed (≥ 3 months) variceal bleeding in the afferent jejunal loop. Materials and Methods Eleven consecutive patients (age range, 2–79 years; eight men and three women) who underwent portal stenting between April 2009 and December 2015 were included in the study. Preoperative medical history and the postoperative clinical course were reviewed. Characteristics of portal occlusion and details of procedures were also investigated. Technical success, treatment efficacy (defined as disappearance of jejunal varix on follow-up CT), and clinical success were analyzed. Primary stent patency rate was plotted using the Kaplan-Meier method. Results All patients underwent hepatobiliary-pancreatic cancer surgery except two children with liver transplantation for biliary atresia. Portal occlusion was caused by benign postoperative change (n = 6) and local tumor recurrence (n = 5). Variceal bleeding occurred at 27 months (4 to 72 months) and portal stenting was performed at 37 months (4 to 121 months), on average, postoperatively. Technical success, treatment efficacy, and clinical success rates were 90.9, 100, and 81.8%, respectively. The primary patency rate of portal stent was 88.9% during the mean follow-up period of 9 months. Neither procedure-related complication nor mortality occurred. Conclusion Interventional portal stenting is an effective treatment for delayed jejunal variceal bleeding due to portal occlusion after hepatobiliary-pancreatic surgery. PMID:28860900

Identification of potential drug targets based on a computational biology algorithm for venous thromboembolism.

PubMed

Xie, Ruiqiang; Li, Lei; Chen, Lina; Li, Wan; Chen, Binbin; Jiang, Jing; Huang, Hao; Li, Yiran; He, Yuehan; Lv, Junjie; He, Weiming

2017-02-01

Venous thromboembolism (VTE) is a common, fatal and frequently recurrent disease. Changes in the activity of different coagulation factors serve as a pathophysiological basis for the recurrent risk of VTE. Systems biology approaches provide a better understanding of the pathological mechanisms responsible for recurrent VTE. In this study, a novel computational method was presented to identify the recurrent risk modules (RRMs) based on the integration of expression profiles and human signaling network, which hold promise for achieving new and deeper insights into the mechanisms responsible for VTE. The results revealed that the RRMs had good classification performance to discriminate patients with recurrent VTE. The functional annotation analysis demonstrated that the RRMs played a crucial role in the pathogenesis of VTE. Furthermore, a variety of approved drug targets in the RRM M5 were related to VTE. Thus, the M5 may be applied to select potential drug targets for combination therapy and the extended treatment of VTE.

High-energy long duration frequency-doubled Nd:YAG laser and application to venous occlusion

NASA Astrophysics Data System (ADS)

Zhang, Laiming; Yang, Guilong; Li, Dianjun; Lu, Qipeng; Gu, Huadong; Zhu, Linlin; Zhao, Zhenwu; Li, Xin; Tang, Yuguo; Guo, Jin

2005-01-01

Laser treatment represents an attractive option to other methods of vessel diseases especially varicose veins. A long pulse (30~50ms) 532nm laser (Fig.1) is used in our experiments with the pulse duration matching the thermal relaxation time of the vessels and the green laser matching the absorption spectrum peak of the blood. Laser irradiates nude vein vessels directly or exterior skin to finish operation faster and to acquire the practical data for upper enteron varicose vein treatment in several animal experiments performed in vivo. The 5J-energy pulse allows us to finely occlude rabbit or dog"s vein vessels up to 2 mm in diameter when irradiating them off external skin (Fig.2). Blood vessels are occluded at once and later biopsy specimens show the immediate and long-term lasting occlusion effect. While irradiating vessels directly (Fig.3), the vessels are usually irradiated to perforate, detailed causes are still under investigation. Animal experiments show long pulse green laser therapy is a safe and effective solution to the vein"s occlusion, which promises such laser with high energy of each pulse and 30~50 ms duration is an ideal candidate for vessel diseases treatment.

Implantable venous ports in pediatric oncology: experience of single institution in Russia.

PubMed

Rykov, Maxim Yu; Polyakov, Vladimir G

2016-07-12

To review our experience with implantable venous port-systems (IVPs) in pediatric cancer patients. From 2010 to 2015 we were monitoring the treatment of 163 children (aged 3 months to 17 years) with oncologic diseases. These patients underwent venous port implantations. During insertion of 163 IVPs the following complications and technical difficulties were present: unintended puncture of the common carotid artery (CCA) during the puncture of the internal jugular vein (IJV) - 7 cases (4.3%); retrograde positioning of the distal end of the guidewire in the IJV - 17 cases (14.4%); placement of the distal end of the guidewire into the punctured subclavian vein (SV) - 12 cases (7.6%); difficulties driving the guidewire into the IJV after successful puncture - 15 cases (9.3%). The use of 163 IVPs was complicated by the following: venous port contamination - 4 cases (2.5%); occlusion of the IVPs by a clot - 8 cases (5%); withdrawal of the Huber needle bevel from the port chamber - 22 cases (13.6%); subcutaneous fat layer thinning above the port chamber - 3 cases (1.7%). There are many complications, but they can be reduced by proper choice of materials and methodology.

Central venous pressure and mean circulatory filling pressure in the dogfish Squalus acanthias: adrenergic control and role of the pericardium.

PubMed

Sandblom, Erik; Axelsson, Michael; Farrell, Anthony P

2006-11-01

Subambient central venous pressure (Pven) and modulation of venous return through cardiac suction (vis a fronte) characterizes the venous circulation in sharks. Venous capacitance was estimated in the dogfish Squalus acanthias by measuring the mean circulatory filling pressure (MCFP) during transient occlusion of cardiac outflow. We tested the hypothesis that venous return and cardiac preload can be altered additionally through adrenergic changes of venous capacitance. The experiments involved the surgical opening of the pericardium to place a perivascular occluder around the conus arteriosus. Another control group was identically instrumented, but lacked the occluder, and was subjected to the same pharmacological protocol to evaluate how pericardioectomy affected cardiovascular status. Routine Pven was negative (-0.08+/-0.02 kPa) in control fish but positive (0.09+/-0.01 kPa) in the pericardioectomized group. Injections of 5 microg/kg body mass (Mb) of epinephrine and phenylephrine (100 microg/kg Mb) increased Pven and MCFP, whereas isoproterenol (1 microg/kg Mb) decreased both variables. Thus, constriction and relaxation of the venous vasculature were mediated through the respective stimulation of alpha- and beta-adrenergic receptors. Alpha-adrenergic blockade with prazosin (1 mg/kg Mb) attenuated the responses to phenylephrine and decreased resting Pven in pericardioectomized animals. Our results provide convincing evidence for adrenergic control of the venous vasculature in elasmobranchs, although the pericardium is clearly an important component in the modulation of venous function. Thus active changes in venous capacitance have previously been underestimated as an important means of modulating venous return and cardiac performance in this group.

Venous Access Ports: Indications, Implantation Technique, Follow-Up, and Complications

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

Walser, Eric M., E-mail: walser.eric@mayo.edu

The subcutaneous venous access device (SVAD or 'port') is a critical component in the care of patients with chronic disease. The modern SVAD provides reliable access for blood withdrawal and medication administration with minimal disruption to a patient's lifestyle. Because of improved materials and catheter technology, today's ports are lighter and stronger and capable of high-pressure injections of contrast for cross-sectional imaging. The majority of SVAD placement occurs in interventional radiology departments due to their ability to provide this service at lower costs, lower, complication rates, and greater volumes. Port-insertion techniques vary depending on the operator, but all consist ofmore » catheter placement in the central venous circulation followed by subcutaneous pocket creation and port attachment to the catheter with fixation and closure of the pocket. Venous access challenges occasionally occur in patients with central vein occlusions, necessitating catheterization of collateral veins or port placement in alternate locations. Complications of SVADs include those associated with the procedure as well as short- (<30 days) and long-term problems. Procedural and early complications are quite rare due to the near-universal use of real-time ultrasound guidance for vein puncture, but they can include hematoma, catheter malposition, arrhythmias, and pneumothorax. Late problems include both thrombotic complications (native venous or port-catheter thrombosis) and infections (tunnel or pocket infections or catheter-associated bloodstream infections). Most guidelines suggest that 0.3 infections/1000 catheter days is an appropriate upper threshold for the insertion of SVADs.« less

Evidence for an enduring ischaemic penumbra following central retinal artery occlusion, with implications for fibrinolytic therapy.

PubMed

McLeod, David; Beatty, Stephen

2015-11-01

The rationale behind hyperacute fibrinolytic therapy for cerebral and retinal arterial occlusion is to rescue ischaemic cells from irreversible damage through timely restitution of tissue perfusion. In cerebral stroke, an anoxic tissue compartment (the "infarct core") is surrounded by a hypoxic compartment (the "ischaemic penumbra"). The latter comprises electrically-silent neurons that undergo delayed apoptotic cell death within 1-6 h unless salvaged by arterial recanalisation. Establishment of an equivalent hypoxic compartment within the inner retina following central retinal artery occlusion (CRAO) isn't widely acknowledged. During experimental CRAO, electroretinography reveals 3 oxygenation-based tissue compartments (anoxic, hypoxic and normoxic) that contribute 32%, 27% and 41% respectively to the pre-occlusion b-wave amplitude. Thus, once the anoxia survival time (≈2 h) expires, the contribution from the infarcted posterior retina is irreversibly extinguished, but electrical activity continues in the normoxic periphery. Inbetween these compartments, an annular hypoxic zone (the "penumbra obscura") endures in a structurally-intact but functionally-impaired state until retinal reperfusion allows rapid recovery from electrical silence. Clinically, residual circulation of sufficient volume flow rate generates the heterogeneous fundus picture of "partial" CRAO. Persistent retinal venous hypoxaemia signifies maximal extraction of oxygen by an enduring "polar penumbra" that permeates or largely replaces the infarct core. On retinal reperfusion some days later, the retinal venous oxygen saturation reverts to normal and vision improves. Thus, penumbral inner retina, marginally oxygenated by the choroid or by residual circulation, isn't at risk of delayed apoptotic infarction (unlike hypoxic cerebral cortex). Emergency fibrinolytic intervention is inappropriate, therefore, once the duration of CRAO exceeds 2 h. Copyright © 2015 Elsevier Ltd. All rights reserved.

Near-infrared spectroscopic assessment of oxygen delivery to free flaps on monkeys following vascular occlusions and inhalation of pure oxygen

NASA Astrophysics Data System (ADS)

Tian, Fenghua; Ding, Haishu; Cai, Zhigang; Wang, Guangzhi; Zhao, Fuyun

2002-04-01

In recent studies, near-infrared spectroscopy (NIRS) has been considered as a potentially ideal noninvasive technique for the postoperative monitoring of plastic surgery. In this study, free flaps were raised on rhesus monkeys' forearms and oxygen delivery to these flaps was monitored following vascular occlusions and inhalation of pure oxygen. Optical fibers were adopted in the probe of the oximeter so that the detection could be performed in reflectance mode. The distance between emitter and detector can be adjusted easily to achieve the best efficacy. Different and repeatable patterns of changes were measured following vascular occlusions (arterial occlusion, venous occlusion and total occlusion) on flaps. It is clear that the near-infrared spectroscopy is capable of postoperatively monitoring vascular problems in flaps. NIRS showed high sensitivity to detect the dynamic changes in flaps induced by inhalation of pure oxygen in this study. The experimental results indicated that it was potential to assess tissue viability utilizing the dynamic changes induced by a noninvasive stimulation. It may be a new assessing method that is rapid, little influenced by other factors and brings less discomfort to patients.

Optic disc laceration with combined retinal artery and vein occlusion following penetrating injury.

PubMed

Lee, Mun-Wai; Lee, Shu-Yen; Ong, Sze-Guan

2007-07-01

Ocular trauma is a major cause of unilateral blindness and male adults in the working age group have been found to have higher rates of ocular injury. A case of a work-related penetrating ocular trauma with an intraocular foreign body causing an optic disc laceration and consequently a combined retinal arterial and venous occlusion is presented. The patient did not recover useful vision despite early surgical intervention. This case highlights an unusual sequelae following penetrating ocular trauma as well as the importance of safety eyewear for individuals in high-risk occupations.

Collateral Circulation in Chronic Total Occlusions - an interventional perspective.

PubMed

Choo, Gim-Hooi

2015-09-09

Human coronary collaterals are inter-coronary communications that are believed to be present from birth. In the presence of chronic total occlusions, recruitment of flow via these collateral anastomoses to the arterial segment distal to occlusion provide an alternative source of blood flow to the myocardial segment at risk. This mitigates the ischemic injury. Clinical outcome of coronary occlusion ie. severity of myocardial infarction/ischemia, impairment of cardiac function and possibly survival depends not only on the acuity of the occlusion, extent of jeopardized myocardium, duration of ischemia but also to the adequacy of collateral circulation. Adequacy of collateral circulation can be assessed by various methods. These coronary collateral channels have been used successfully as a retrograde access route for percutaneous recanalization of chronic total occlusions. Factors that promote angiogenesis and further collateral remodeling ie. arteriogenesis have been identified. Promotion of collateral growth as a therapeutic target in patients with no suitable revascularization option is an exciting proposal.

Magnetic resonance venography and three-dimensional image fusion guidance provide a novel paradigm for endovascular recanalization of chronic central venous occlusion.

PubMed

Schwein, Adeline; Lu, Tony; Chinnadurai, Ponraj; Kitkungvan, Danai; Shah, Dipan J; Chakfe, Nabil; Lumsden, Alan B; Bismuth, Jean

2017-01-01

Endovascular recanalization is considered first-line therapy for chronic central venous occlusion (CVO). Unlike arteries, in which landmarks such as wall calcifications provide indirect guidance for endovascular navigation, sclerotic veins without known vascular branching patterns impose significant challenges. Therefore, safe wire access through such chronic lesions mostly relies on intuition and experience. Studies have shown that magnetic resonance venography (MRV) can be performed safely in these patients, and the boundaries of occluded veins may be visualized on specific MRV sequences. Intraoperative image fusion techniques have become more common to guide complex arterial endovascular procedures. The aim of this study was to assess the feasibility and utility of MRV and intraoperative cone-beam computed tomography (CBCT) image fusion technique during endovascular CVO recanalization. During the study period, patients with symptomatic CVO and failed standard endovascular recanalization underwent further recanalization attempts with use of intraoperative MRV image fusion guidance. After preoperative MRV and intraoperative CBCT image coregistration, a virtual centerline path of the occluded segment was electronically marked in MRV and overlaid on real-time two-dimensional fluoroscopy images. Technical success, fluoroscopy times, radiation doses, number of venograms before recanalization, and accuracy of the virtual centerline overlay were evaluated. Four patients underwent endovascular CVO recanalization with use of intraoperative MRV image fusion guidance. Mean (± standard deviation) time for image fusion was 6:36 ± 00:51 mm:ss. The lesion was successfully crossed in all patients without complications. Mean fluoroscopy time for lesion crossing was 12.5 ± 3.4 minutes. Mean total fluoroscopy time was 28.8 ± 6.5 minutes. Mean total radiation dose was 15,185 ± 7747 μGy/m 2 , and mean radiation dose from CBCT acquisition was 2788 ± 458 μGy/m 2 (18% of

Effects of Heparin and ε-Aminocaproic Acid in Dogs on Plasmin- 125I Generation in Response to Urokinase Injections and Venous Injury

PubMed Central

Takeda, Y.; Parkhill, T. R.; Nakabayashi, M.

1972-01-01

The isotopic method described previously for quantification of plasmin- 125I by disc gel electrophoresis was modified by inclusion of euglobulin precipitation to expand its applicability to plasmas containing low radioactivity of plasmin- 125I and plasminogen- 125I. It was found that the euglobulin precipitation method precipitates 72.4±2.1 (sd)% of both plasmin- 125I and plasminogen- 125I. Using this method and plasminogen- 125I as a tracer, studies were first made of the effects of heparin and ε-aminocaproic acid in dogs on plasmin- 125I generation in responese to a single injection of urokinase and to venous injury; second, of the effects of venous occlusion and thrombosis on plasmin- 125I generation; and third, in vitro studies of plasminogen- 125I affinity to fibrin and its activation in blood clots. The venous injury was produced by the damage of venous endothelium by an injection of 90% phenol and the thrombosis by a thrombin injection into an occluded vein. Heparin and ε-aminocaproic acid under the present experimental conditions inhibited about 78 and 100%, respectively of plasmin- 125I generation by the urokinase injection. Similar inhibitory effects of heparin and ε-aminocaproic acid were observed on plasmin- 125I generation in response to venous injury. The venous occlusion caused a small degree of plasmin- 125I generation, but thrombin thrombosis did not seem to stimulate the generation of plasmin- 125I. The in vitro studies showed that plasminogen- 125I does not have a specific affinity to fibrin and is incorporated into blood clots in approximately equal concentrations as those in serum during clotting processes, and that blood clots per se do not stimulate plasmin- 125I generation. These results suggest that injured veins release considerable amounts of vascular plasminogen activators into circulation and that these play an important role in thrombus dissolution in vivo. PMID:4262519

Proof of concept non-invasive estimation of peripheral venous oxygen saturation.

PubMed

Khan, Musabbir; Pretty, Chris G; Amies, Alexander C; Balmer, Joel; Banna, Houda E; Shaw, Geoffrey M; Geoffrey Chase, J

2017-05-19

Pulse oximeters continuously monitor arterial oxygen saturation. Continuous monitoring of venous oxygen saturation (SvO 2 ) would enable real-time assessment of tissue oxygen extraction (O 2 E) and perfusion changes leading to improved diagnosis of clinical conditions, such as sepsis. This study presents the proof of concept of a novel pulse oximeter method that utilises the compliance difference between arteries and veins to induce artificial respiration-like modulations to the peripheral vasculature. These modulations make the venous blood pulsatile, which are then detected by a pulse oximeter sensor. The resulting photoplethysmograph (PPG) signals from the pulse oximeter are processed and analysed to develop a calibration model to estimate regional venous oxygen saturation (SpvO 2 ), in parallel to arterial oxygen saturation estimation (SpaO 2 ). A clinical study with healthy adult volunteers (n = 8) was conducted to assess peripheral SvO 2 using this pulse oximeter method. A range of physiologically realistic SvO 2 values were induced using arm lift and vascular occlusion tests. Gold standard, arterial and venous blood gas measurements were used as reference measurements. Modulation ratios related to arterial and venous systems were determined using a frequency domain analysis of the PPG signals. A strong, linear correlation (r 2  = 0.95) was found between estimated venous modulation ratio (R Ven ) and measured SvO 2 , providing a calibration curve relating measured R Ven to venous oxygen saturation. There is a significant difference in gradient between the SpvO 2 estimation model (SpvO 2  = 111 - 40.6*R) and the empirical SpaO 2 estimation model (SpaO 2  = 110 - 25*R), which yields the expected arterial-venous differences. Median venous and arterial oxygen saturation accuracies of paired measurements between pulse oximeter estimated and gold standard measurements were 0.29 and 0.65%, respectively, showing good accuracy of the pulse oximeter system

Reproducibility of forearm vasodilator response to intra-arterial infusion of calcitonin gene-related peptide assessed by venous occlusion plethysmography

PubMed Central

Vanmolkot, Floris H M; de Hoon, Jan N J M

2005-01-01

Aims To assess the reproducibility of the forearm blood flow (FBF) response to intra-arterial infusion of calcitonin-gene related peptide (CGRP), measured by venous occlusion plethysmography. In addition, to compare different ways of expressing the FBF response and perform sample size calculations. Methods On two separate visits, CGRP (10 ng min−1 dl−1 forearm) was infused for 45 min into the brachial artery of six healthy subjects. Reproducibility was assessed by calculating mean difference, repeatability coefficient, within-subject coefficient of variation (WCV) and intraclass correlation coefficient. Results CGRP increased FBF from 2.8 ± 0.4 and 3.2 ± 0.7 (at baseline) to 15.4 ± 1.4 and 15.2 ± 1.5 ml min−1 dl−1 forearm (at 45 min) on visits 1 and 2, respectively (P < 0.0001 for both visits). Mean difference in FBF at 45 min between both visits was 0.3 ml min−1 dl−1 forearm (repeatability coefficient: 4.1 ml min−1 dl−1 forearm). This FBF response appeared to be more reproducible when expressed as absolute FBF in the infused arm (WCV 11%) compared with absolute FBF-ratio between both arms (WCV 37%), percentage change from baseline in FBF in the infused arm (WCV 29%) and percentage change from baseline in FBF-ratio (WCV 40%). When expressed as absolute FBF, a sample size of five (95% confidence interval: 2–12) subjects gives 90% power at a type I error probability of 0.05 to detect a 25% shift in FBF response. Conclusions Intra-arterial infusion of CGRP results in a forearm vasodilator response which is reproducible between days. This response is most reproducible when expressed as absolute FBF. The presented methodology provides a suitable pharmacodynamic model to assess the in vivo activity of CGRP-receptor antagonists in a small number of subjects. PMID:15801933

Novel approach to epicardial pacemaker implantation in patients with limited venous access.

PubMed

Costa, Roberto; Scanavacca, Mauricio; da Silva, Kátia Regina; Martinelli Filho, Martino; Carrillo, Roger

2013-11-01

Limited venous access in certain patients increases the procedural risk and complexity of conventional transvenous pacemaker implantation. The purpose of this study was to determine a minimally invasive epicardial approach using pericardial reflections for dual-chamber pacemaker implantation in patients with limited venous access. Between June 2006 and November 2011, 15 patients underwent epicardial pacemaker implantation. Procedures were performed through a minimally invasive subxiphoid approach and pericardial window with subsequent fluoroscopy-assisted lead placement. Mean patient age was 46.4 ± 15.3 years (9 male [(60.0%], 6 female [40.0%]). The new surgical approach was used in patients determined to have limited venous access due to multiple abandoned leads in 5 (33.3%), venous occlusion in 3 (20.0%), intravascular retention of lead fragments from prior extraction in 3 (20.0%), tricuspid valve vegetation currently under treatment in 2 (13.3%), and unrepaired intracardiac defects in 2 (13.3%). All procedures were successful with no perioperative complications or early deaths. Mean operating time for isolated pacemaker implantation was 231.7 ± 33.5 minutes. Lead placement on the superior aspect of right atrium, through the transverse sinus, was possible in 12 patients. In the remaining 3 patients, the atrial lead was implanted on the left atrium through the oblique sinus, the postcaval recess, or the left pulmonary vein recess. None of the patients displayed pacing or sensing dysfunction, and all parameters remained stable throughout the follow-up period of 36.8 ± 25.1 months. Epicardial pacemaker implantation through pericardial reflections is an effective alternative therapy for those patients requiring physiologic pacing in whom venous access is limited. © 2013 Heart Rhythm Society. All rights reserved.

Cerebral venous infarction: a potentially avoidable complication of deep brain stimulation surgery.

PubMed

Morishita, Takashi; Okun, Michael S; Burdick, Adam; Jacobson, Charles E; Foote, Kelly D

2013-01-01

Despite numerous reports on the morbidity and mortality of deep brain stimulation (DBS), cerebral venous infarction has rarely been reported. We present four cases of venous infarct secondary to DBS surgery. The diagnosis of venous infarction was based on 1) delayed onset of new neurologic deficits on postoperative day 1 or 2; 2) significant edema surrounding the superficial aspect of the implanted lead, with or without subcortical hemorrhage on CT scan. Four cases (0.8% per lead, 1.3% per patient) of symptomatic cerebral venous infarction were identified out of 500 DBS lead implantation procedures between July 2002 and August 2009. All four patients had Parkinson's disease. Their DBS leads were implanted in the subthalamic nucleus (n = 2), and the globus pallidus internus (n = 2). Retrospective review of the targeting confirmed that the planned trajectory passed within 3 mm of a cortical vein in two cases for which contrast-enhanced preoperative magnetic resonance (MR) imaging was available. In the other two cases, contrasted targeting images were not obtained preoperatively. Cerebral venous infarction is a potentially avoidable, but serious complication. To minimize its incidence, we propose the use of high-resolution, contrast-enhanced, T1-weighted MR images to delineate cerebral venous anatomy, along with careful stereotactic planning of the lead trajectory to avoid injury to venous structures. © 2013 International Neuromodulation Society.

Comparison of occlusion break responses and vacuum rise times of phacoemulsification systems.

PubMed

Sharif-Kashani, Pooria; Fanney, Douglas; Injev, Val

2014-07-30

Occlusion break surge during phacoemulsification cataract surgery can lead to potential surgical complications. The purpose of this study was to quantify occlusion break surge and vacuum rise time of current phacoemulsification systems used in cataract surgery. Occlusion break surge at vacuum pressures between 200 and 600 mmHg was assessed with the Infiniti® Vision System, the WhiteStar Signature® Phacoemulsification System, and the Centurion® Vision System using gravity-fed fluidics. Centurion Active FluidicsTM were also tested at multiple intraoperative pressure target settings. Vacuum rise time was evaluated for Infiniti, WhiteStar Signature, Centurion, and Stellaris® Vision Enhancement systems. Rise time to vacuum limits of 400 and 600 mmHg was assessed at flow rates of 30 and 60 cc/minute. Occlusion break surge was analyzed by 2-way analysis of variance. The Centurion system exhibited substantially less occlusion break surge than the other systems tested. Surge area with Centurion Active Fluidics was similar to gravity fluidics at an equivalent bottle height. At all Centurion Active Fluidics intraoperative pressure target settings tested, surge was smaller than with Infiniti and WhiteStar Signature. Infiniti had the fastest vacuum rise time and Stellaris had the slowest. No system tested reached the 600-mmHg vacuum limit. In this laboratory study, Centurion had the least occlusion break surge and similar vacuum rise times compared with the other systems tested. Reducing occlusion break surge may increase safety of phacoemulsification cataract surgery.

Temporary Arterial Balloon Occlusion as an Adjunct to Yttrium-90 Radioembolization

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

Hagspiel, Klaus D., E-mail: kdh2n@virginia.edu; Nambiar, Ashwin, E-mail: uvashwin@gmail.com; Hagspiel, Lauren M., E-mail: lmh4gg@virginia.edu

2013-06-15

Purpose. This study was designed to describe the technique of arterial occlusion using a temporary occlusion balloon system as an alternative to coil occlusion during Yttrium-90 radioembolization of hepatic tumors. Methods. Review of charts, angiography, and follow-up imaging studies of consecutive patients undergoing oncological embolization procedures in which a HyperForm system (ev3 Neurovascular, Irvine, CA) was used. Intraprocedural target vessel occlusion and patency of the target vessel on follow-up were recorded. Clinical data and Bremsstrahlung scans were reviewed for evidence of nontarget embolization. Results. Four radioembolization procedures were performed in three patients (all female, age 48-54 (mean 52) years). Fivemore » arteries were temporarily occluded (three gastroduodenal arteries, one right gastric artery, and one cystic artery). All radioembolization procedures were successfully completed. Follow-up imaging (either digital subtraction angiography (DSA) or computed tomography angiography (CTA)) was available for all patients between 28-454 (mean 183) days following the procedure, demonstrating all five vessels to be patent. No clinical or imaging evidence for nontarget embolization was found. Conclusions. Temporary balloon occlusion of small and medium-sized arteries during radioembolization allows safe therapy with preserved postprocedural vessel patency on early and midterm follow-up.« less

Cerebral venous thrombosis with nonhemorrhagic lesions: clinical correlates and prognosis.

PubMed

Ferro, José M; Canhão, Patrícia; Bousser, Marie-Germaine; Stam, Jan; Barinagarrementeria, Fernando; Stolz, Erwin

2010-01-01

Brain imaging of patients with acute cerebral venous thrombosis often shows parenchymal hemorrhagic and nonhemorrhagic lesions. The clinical relevance of nonhemorrhagic lesions is poorly known. In the International Study on Cerebral Vein and Dural Sinus Thrombosis cohort, demographic, clinical, risk factor, prognosis and imaging findings were compared between patients with parenchymal nonhemorrhagic lesions and no hemorrhagic lesions (NHL) and (1) patients with parenchymal hemorrhagic lesions (HL) and (2) patients without brain lesions. Predictors of prognosis at the end of follow-up in the NHL group were analyzed by bivariate and Cox regression methods. We identified 147 patients (23.6%) with NHL. When compared to patients without brain lesions (n = 309), those with NHL more often presented mental status disturbances, aphasia, decreased alertness, motor deficits, seizures, occlusions of the straight sinus, deep venous system and cortical veins. Patients with NHL had a better prognosis in the acute phase and at the end of follow-up than those with HL, but a worse one than patients without brain lesions, as more NHL patients were dead or dependent (modified Rankin Scale score = 3-6) at discharge (19.7 vs. 6.5%, p < 0.001) and final follow-up (14.3 vs. 7.4%, p = 0.03). In Cox regression analysis, coma (HR = 13.7; 95% CI = 4.3-43.7) and thrombosis of the deep venous system (HR = 3.5; 95% CI = 1.4-8.7) were associated with death or dependency at the end of follow-up. Cerebral venous thrombosis patients with NHL are intermediate between patients without brain lesions and those with HL, both in initial clinical picture and prognosis. Copyright 2010 S. Karger AG, Basel.

Limb venous compliance responses to lower body negative pressure in humans with high blood pressure.

PubMed

Goulopoulou, S; Deruisseau, K C; Carhart, R; Kanaley, J A

2012-05-01

This study tested the hypothesis that limb venous responses to baroreceptor unloading are altered in individuals with high blood pressure (HBP) compared with normotensive (NT) controls. Calf venous compliance was assessed in 20 subjects with prehypertension and stage-1 hypertension (mean arterial pressure, MAP: 104±1 mm Hg) and 13 NT controls (MAP: 86±2 mm Hg) at baseline and during lower body negative pressure (LBNP), using venous occlusion plethysmography. Baroreflex sensitivity (BRS) was measured using the sequence technique and total peripheral resistance (TPR) was estimated from finger plethysmography. Baseline venous compliance was not different between groups, but the HBP group had lower baseline lnBRS (2.22±0.14 vs 2.7±0.18 ms mm Hg(-1)) and greater baseline TPR (3828±138 vs 3250±111 dyn sec(-1) cm(-5) m(2), P<0.05). Calf venous compliance was reduced in response to LBNP only in the NT group (P<0.05). The HBP group had a greater increase in TPR (ΔTPR) compared with the NT group (+1649±335 vs +718±196 dyn sec(-1) cm(-5) m(2), P<0.05). In conclusion, the early stages of hypertension are characterized by an attenuated venoconstrictor response to baroreceptor unloading, which may compensate for an exaggerated vasoconstrictor response and protect against further increases in blood pressure.

Proximal Occlusion of Medium-Sized Vessels with the Penumbra Occlusion Device: A Study of Safety and Efficacy

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

Jambon, E.; Petitpierre, F.; Brizzi, V.

PurposeTo retrospectively investigate the safety and efficacy of hybrid proximal coiling of various medium-sized vessels (4 to 8 mm) using the Penumbra Occlusion Device (POD).Materials and MethodsFrom October 2014 to February 2016, 37 proximal embolizations were performed with PODs in 36 patients (mean age: 50.8, range: 10–86; 29 male, 7 female). Vessel occlusions were achieved under fluoroscopic guidance using a 2.7 French microcatheter. Among the 36 vessels targeted, 16 were splenic arteries, 11 renal arteries, 4 mesenteric arteries, 3 arteriovenous fistulae, 1 iliac artery, and 1 gonadal vein. Intermittent follow-up angiography was performed to assess the flow for final occlusion. Outcomesmore » and complications were assessed by clinical and/or imaging follow-up.ResultsTo produce proximal occlusion of the intended vessels, the POD was used alone in 19 embolizations (51.4 %). In 12 procedures (32.4 %), POD was used as a coil constrainer to secure the coil construct. In 6 procedures (16.2 %), additional embolic devices were used to achieve vessel occlusion after initial POD deployment. After a mean follow-up of 3.2 months, no POD migration was observed but two complications occurred (5.4 %): one post embolic syndrome and one extensive infarction with splenic abscess.ConclusionThe POD system allows safe and effective proximal embolization of medium-sized vessels in a variety of clinical settings.« less

An algorithm of adaptive scale object tracking in occlusion

NASA Astrophysics Data System (ADS)

Zhao, Congmei

2017-05-01

Although the correlation filter-based trackers achieve the competitive results both on accuracy and robustness, there are still some problems in handling scale variations, object occlusion, fast motions and so on. In this paper, a multi-scale kernel correlation filter algorithm based on random fern detector was proposed. The tracking task was decomposed into the target scale estimation and the translation estimation. At the same time, the Color Names features and HOG features were fused in response level to further improve the overall tracking performance of the algorithm. In addition, an online random fern classifier was trained to re-obtain the target after the target was lost. By comparing with some algorithms such as KCF, DSST, TLD, MIL, CT and CSK, experimental results show that the proposed approach could estimate the object state accurately and handle the object occlusion effectively.

Complex left profunda femoris vein to renal vein bypass for the management of progressive chronic iliofemoral occlusion.

PubMed

Anaya-Ayala, Javier E; Adams, Matthew K; Telich-Tarriba, Jose E; Dresser, Kelly L; Ismail, Nyla; Peden, Eric K

2013-01-01

Chronic occlusions of the inferior vena cava (IVC) and iliofemoral veins are long-term sequelae of deep venous thrombosis (DVT) that can lead to postthrombotic syndrome (PTS). Patients may present with a wide spectrum of signs and symptoms, ranging from mild discomfort and swelling to severe venous hypertension and ulcerations. We report a 68-year-old man who had a history of left lower extremity DVT after a laminectomy and who developed PTS with nonhealing ulcers. The patient underwent a cross-pubic femorofemoral venous bypass that failed to improve his clinical status. After unsuccessful endovascular attempts for recanalization of the iliofemoral segment, a profunda femoris to IVC bypass was performed. The symptoms recurred 2 years later. Venography revealed restenosis at the caval anastomosis that did not resolve by endovascular means. A surgical revision was performed, and given the quality of the IVC, a jump bypass was created to the left renal vein. The swelling improved and the ulcers healed completely. Twenty-eight months after the complex reconstructions, he remains ulcer-free with mild edema controlled with stockings. Venous reconstructions remain a viable option for patients with symptomatic and recalcitrant nonmalignant obstruction of the large veins. Copyright © 2013 Annals of Vascular Surgery Inc. Published by Elsevier Inc. All rights reserved.

Lack of association between venous hemodynamics, venous morphology and the postthrombotic syndrome after upper extremity deep venous thrombosis.

PubMed

Czihal, M; Paul, S; Rademacher, A; Bernau, C; Hoffmann, U

2015-03-01

To explore the association of the postthrombotic syndrome with venous hemodynamics and morphological abnormalities after upper extremity deep venous thrombosis. Thirty-seven patients with a history of upper extremity deep venous thrombosis treated with anticoagulation alone underwent a single study visit (mean time after diagnosis: 44.4 ± 28.1 months). Presence and severity postthrombotic syndrome were classified according to the modified Villalta score. Venous volume and venous emptying were determined by strain-gauge plethysmography. The arm veins were assessed for postthrombotic abnormalities by ultrasonography. The relationship between postthrombotic syndrome and hemodynamic and morphological sequelae was evaluated using univariate significance tests and Spearman's correlation analysis. Fifteen of 37 patients (40.5%) developed postthrombotic syndrome. Venous volume and venous emptying of the arm affected by upper extremity deep venous thrombosis did not correlate with the Villalta score (rho = 0.17 and 0.19; p = 0.31 and 0.25, respectively). Residual morphological abnormalities, as assessed by ultrasonography, did not differ significantly between patients with and without postthrombotic syndrome (77.3% vs. 86.7%, p = 0.68). Postthrombotic syndrome after upper extremity deep venous thrombosis is not associated with venous hemodynamics or residual morphological abnormalities. © The Author(s) 2013 Reprints and permissions: sagepub.co.uk/journalsPermissions.nav.

Upper Body Venous Compliance Exceeds Lower Body Venous Compliance in Humans

NASA Technical Reports Server (NTRS)

Watenpaugh, Donald E.

1996-01-01

Human venous compliance hypothetically decreases from upper to lower body as a mechanism for maintenance of the hydrostatic indifference level 'headward' in the body, near the heart. This maintains cardiac filling pressure, and thus cardiac output and cerebral perfusion, during orthostasis. This project entailed four steps. First, acute whole-body tilting was employed to alter human calf and neck venous volumes. Subjects were tilted on a tilt table equipped with a footplate as follows: 90 deg, 53 deg, 30 deg, 12 deg, O deg, -6 deg, -12 deg, -6 deg, O deg, 12 deg, 30 deg, 53 deg, and 90 deg. Tilt angles were held for 30 sec each, with 10 sec transitions between angles. Neck volume increased and calf volume decreased during head-down tilting, and the opposite occurred during head-up tilt. Second, I sought to cross-validate Katkov and Chestukhin's (1980) measurements of human leg and neck venous pressures during whole-body tilting, so that those data could be used with volume data from the present study to calculate calf and neck venous compliance (compliance = (Delta)volume/(Delta)pressure). Direct measurements of venous pressures during postural chances and whole-body tilting confirmed that the local changes in venous pressures seen by Katkov and Chestukhin (1980) are valid. The present data also confirmed that gravitational changes in calf venous pressure substantially exceed those changes in upper body venous pressure. Third, the volume and pressure data above were used to find that human neck venous compliance exceeds calf venous compliance by a factor of 6, thereby upholding the primary hypothesis. Also, calf and neck venous compliance correlated significantly with each other (r(exp 2) = 0.56). Fourth, I wished to determine whether human calf muscle activation during head-up tilt reduces calf venous compliance. Findings from tilting and from supine assessments of relaxed calf venous compliance were similar, indicating that tilt-induced muscle activation is

The unsuitability of implantable Doppler probes for the early detection of renal vascular complications – a porcine model for prevention of renal transplant loss

PubMed Central

Jespersen, Bente; Møldrup, Ulla; Keller, Anna K.

2017-01-01

Background Vascular occlusion is a rare, but serious complication after kidney transplantation often resulting in graft loss. We therefore aimed to develop an experimental porcine model for stepwise reduction of the renal venous blood flow and to compare an implantable Doppler probe and microdialysis for fast detection of vascular occlusion. Methods In 20 pigs, implantable Doppler probes were placed on the renal artery and vein and a microdialysis catheter was placed in the renal cortex. An arterial flowprobe served as gold standard. Following two-hour baseline measurements, the pigs were randomised to stepwise venous occlusion, complete venous occlusion, complete arterial occlusion or controls. Results All parameters were stable through baseline measurements. Glutamate and lactate measured by microdialysis increased significantly (p = 0.02 and p = 0.03 respectively) 30 minutes after a 2/3 (66%) reduction in renal blood flow. The implantable Doppler probe was not able to detect flow changes until there was total venous occlusion. Microdialysis detected changes in local metabolism after both arterial and venous occlusion; the implantable Doppler probe could only detect vascular occlusions on the vessel it was placed. Conclusions We developed a new model for stepwise renal venous blood flow occlusion. Furthermore, the first comparison of the implantable Doppler probe and microdialysis for detection of renal vascular occlusions was made. The implantable Doppler probe could only detect flow changes after a complete occlusion, whereas microdialysis detected changes earlier, and could detect both arterial and venous occlusion. Based on these results, the implantable Doppler probe for early detection of vascular occlusions cannot be recommended. PMID:28542429

Comparison of occlusion break responses and vacuum rise times of phacoemulsification systems

PubMed Central

2014-01-01

Background Occlusion break surge during phacoemulsification cataract surgery can lead to potential surgical complications. The purpose of this study was to quantify occlusion break surge and vacuum rise time of current phacoemulsification systems used in cataract surgery. Methods Occlusion break surge at vacuum pressures between 200 and 600 mmHg was assessed with the Infiniti® Vision System, the WhiteStar Signature® Phacoemulsification System, and the Centurion® Vision System using gravity-fed fluidics. Centurion Active FluidicsTM were also tested at multiple intraoperative pressure target settings. Vacuum rise time was evaluated for Infiniti, WhiteStar Signature, Centurion, and Stellaris® Vision Enhancement systems. Rise time to vacuum limits of 400 and 600 mmHg was assessed at flow rates of 30 and 60 cc/minute. Occlusion break surge was analyzed by 2-way analysis of variance. Results The Centurion system exhibited substantially less occlusion break surge than the other systems tested. Surge area with Centurion Active Fluidics was similar to gravity fluidics at an equivalent bottle height. At all Centurion Active Fluidics intraoperative pressure target settings tested, surge was smaller than with Infiniti and WhiteStar Signature. Infiniti had the fastest vacuum rise time and Stellaris had the slowest. No system tested reached the 600-mmHg vacuum limit. Conclusions In this laboratory study, Centurion had the least occlusion break surge and similar vacuum rise times compared with the other systems tested. Reducing occlusion break surge may increase safety of phacoemulsification cataract surgery. PMID:25074069

Management of central venous catheters in pediatric onco-hematology using 0.9% sodium chloride and positive-pressure-valve needleless connector.

PubMed

Buchini, Sara; Scarsini, Sara; Montico, Marcella; Buzzetti, Roberto; Ronfani, Luca; Decorti, Cinzia

2014-08-01

To describe, in a sample of pediatric onco-hematological patients, the rate of occlusions in unused central venous catheters (CVC) flushed once a week with a 0.9% sodium chloride solution through a positive-pressure-valve needleless connector. Retrospective cohort study. Subjects aged 0-17 years were identified through a manual search in medical and nursing records and were observed for two years or until the occurrence of one of the following events: start or resume of continuous infusion; CVC removal; death. The primary study outcome was the frequency of CVC occlusion (partial or complete). Fifty-one patients were identified (median age 6 years). The median duration of follow-up was 169 days (IQR 111-305). During the follow up period, 14 patients (27%) had one CVC occlusion, in 2 cases (4%) the occlusion was complete, in 12 (23%) partial. All the occlusions were solved without the need for catheter removal. The lumen diameter ≤ 4.2 vs > 4.2 French showed a statistically significant association with occlusion at multivariate analysis (OR 4.0; 95% CI 1.1-14.7). Our findings are reassuring with respect to the management of the CVC using the adopted protocol. The study provides useful information for patient care, by verifying the performance of the adopted CVC management protocol and by identifying critical areas for nursing care. Copyright © 2014 Elsevier Ltd. All rights reserved.

Cerebral venous hypertension and blindness: a reversible complication.

PubMed

Cuadra, Salvador A; Padberg, Frank T; Turbin, Roger E; Farkas, Jeffrey; Frohman, Larry P

2005-10-01

A 57-year-old woman developed blindness during treatment for sarcoidosis-induced end-stage renal disease. An initial renal transplantation failed, and hemoaccess was maintained with multiple central catheters and upper extremity prosthetic arteriovenous grafts. A successful second transplantation eliminated her need for hemodialysis, but a right brachial to internal jugular graft remained patent. Progressive visual loss 2 years after transplantation prompted ophthalmic evaluation which initially revealed unilateral left optic nerve edema and visual loss, ultimately worsening over several months to no light perception in the left eye, 20/60 vision in the right eye, and bilateral papilledema. Arteriography demonstrated cerebral venous hypertension attributed to the functioning hemoaccess graft. Permanent graft occlusion normalized the papilledema, and visual field defects in the right eye and visual acuity returned to 20/20 in the right eye.

Three-dimensional gadolinium-enhanced magnetic resonance venography in suspected thrombo-occlusive disease of the central chest veins.

PubMed

Kroencke, T J; Taupitz, M; Arnold, R; Fritsche, L; Hamm, B

2001-11-01

To determine the usefulness of high-resolution three-dimensional (3D) gadolinium-enhanced magnetic resonance venography (MRV) in the evaluation of central venous thrombo-occlusive disease of the chest. Prospective study. University hospital. Sixteen consecutive patients with clinically suspected thrombosis of the superior vena cava, subclavian, brachiocephalic/innominate, internal jugular, or axillary veins. Thirteen patients had a neoplasm, two patients had a connective tissue disease, and one patient had a history of strenuous exercise. Twelve of 16 patients had prior central venous catheter placement. MRI was correlated with color-coded duplex sonography (CCDS) in 7 of 16 patients, digital subtraction angiography (DSA) in 3 of 16 patients, and CT in 2 of 16 patients. Contrast-enhanced MRV was performed in a total of 20 examinations. A 3D data set (gradient echo; time to repeat, 4.6 ms; time to echo, 1.8 ms; flip angle, 30 degrees; time of acquisition, 23 s; 512 matrix/64 partitions; slice thickness, 1.5 mm) was acquired in the arterial and venous phase. Overall image quality was assessed on a 5-point scale. The presence, site, and extent of thrombus, as well as presence of an intravascular device, were determined. Overall image quality was rated very good (1 point) in 7 of 16 cases (44%) and good (2 points) in 9 of 16 cases (56%). Thrombus was detected in 16 of 16 patients, and complete extent of disease could be determined in 15 of 16 patients (94%). MRV did not miss any finding obtained by CCDS, DSA, or CT, and provided additional information in 6 of 16 examinations (38%). Contrast-enhanced MRV is a fast and reliable noninvasive procedure with excellent results regarding detection and determination of the extent of thrombo-occlusive disease of the chest veins.

Noninvasive Imaging of Early Venous Thrombosis by 19F Magnetic Resonance Imaging With Targeted Perfluorocarbon Nanoemulsions.

PubMed

Temme, Sebastian; Grapentin, Christoph; Quast, Christine; Jacoby, Christoph; Grandoch, Maria; Ding, Zhaoping; Owenier, Christoph; Mayenfels, Friederike; Fischer, Jens W; Schubert, Rolf; Schrader, Jürgen; Flögel, Ulrich

2015-04-21

Noninvasive detection of deep venous thrombi and subsequent pulmonary thromboembolism is a serious medical challenge, since both incidences are difficult to identify by conventional ultrasound techniques. Here, we report a novel technique for the sensitive and specific identification of developing thrombi using background-free 19F magnetic resonance imaging, together with α2-antiplasmin peptide (α2AP)-targeted perfluorocarbon nanoemulsions (PFCs) as contrast agent, which is cross-linked to fibrin by active factor XIII. Ligand functionality was ensured by mild coupling conditions using the sterol-based postinsertion technique. Developing thrombi with a diameter<0.8 mm could be visualized unequivocally in the murine inferior vena cava as hot spots in vivo by simultaneous acquisition of anatomic matching 1H and 19F magnetic resonance images at 9.4 T with both excellent signal-to-noise and contrast-to-noise ratios (71±22 and 17±5, respectively). Furthermore, α2AP-PFCs could be successfully applied for the diagnosis of experimentally induced pulmonary thromboembolism. In line with the reported half-life of factor XIIIa, application of α2AP-PFCs>60 minutes after thrombus induction no longer resulted in detectable 19F magnetic resonance imaging signals. Corresponding results were obtained in ex vivo generated human clots. Thus, α2AP-PFCs can visualize freshly developed thrombi that might still be susceptible to pharmacological intervention. Our results demonstrate that 1H/19F magnetic resonance imaging, together with α2AP-PFCs, is a sensitive, noninvasive technique for the diagnosis of acute deep venous thrombi and pulmonary thromboemboli. Furthermore, ligand coupling by the sterol-based postinsertion technique represents a unique platform for the specific targeting of PFCs for in vivo 19F magnetic resonance imaging. © 2015 American Heart Association, Inc.

Rivaroxaban attenuates thrombosis by targeting the NF-κB signaling pathway in a rat model of deep venous thrombus

PubMed Central

Ma, Junhao; Li, Xinxi; Wang, Yang; Yang, Zhenwei; Luo, Jun

2017-01-01

Anticoagulant therapy is commonly used for the prevention and treatment of patients with deep venous thrombus. Evidence has shown that rivaroxaban is a potential oral anticoagulant drug for the acute treatment of venous thromboembolism. However, the rivaroxaban-mediated molecular mechanism involved in the progression of deep venous thrombosis has not been investigated. In the present study, we investigated the efficacy of rivaroxaban and the underlying signaling pathways in the prevention and treatment of rats with deep venous thrombosis. A rat model with deep vein thrombus formation was established and received treatment with rivaroxaban or PBS as control. The thrombin-activatable fibrinolysis inhibitor (TAFI) and plasminogen activator inhibitor-1 (PAI-1) were analyzed both in vitro and in vivo. The progression of thrombosis and stroke was evaluated after treatment with rivaroxaban or PBS. Nuclear factor-κB (NF-κB) signaling pathway in venous endothelial cells and in the rat model of deep venous thrombus was assessed. The therapeutic effects of rivaroxaban were evaluated as determined by changes in deep venous thrombosis in the rat model. Our results showed that rivaroxaban markedly inhibited TAFI and PAI-1 expression levels, neutrophils, tissue factor, neutrophil extracellular traps (NETs), myeloperoxidase and macrophages in venous endothelial cells and in the rat model of deep venous thrombus. Expression levels of ADP, PAIs, von Willebrand factor (vWF) and thromboxane were downregulated in vein endothelial cells and in serum from the experimental rats. Importantly, the incidences of inferior vena cava filter thrombus were protected by rivaroxaban during heparin-induced thrombolysis deep venous thrombosis in the rat model. We observed that activity of the NF-κB signaling pathway was inhibited by rivaroxaban in vein endothelial cells both in vitro and in vivo. Notably, immunohistology indicated that rivaroxaban attenuated deep venous thrombosis and the

Rivaroxaban attenuates thrombosis by targeting the NF-κB signaling pathway in a rat model of deep venous thrombus.

PubMed

Ma, Junhao; Li, Xinxi; Wang, Yang; Yang, Zhenwei; Luo, Jun

2017-12-01

Anticoagulant therapy is commonly used for the prevention and treatment of patients with deep venous thrombus. Evidence has shown that rivaroxaban is a potential oral anticoagulant drug for the acute treatment of venous thromboembolism. However, the rivaroxaban-mediated molecular mechanism involved in the progression of deep venous thrombosis has not been investigated. In the present study, we investigated the efficacy of rivaroxaban and the underlying signaling pathways in the prevention and treatment of rats with deep venous thrombosis. A rat model with deep vein thrombus formation was established and received treatment with rivaroxaban or PBS as control. The thrombin-activatable fibrinolysis inhibitor (TAFI) and plasminogen activator inhibitor-1 (PAI-1) were analyzed both in vitro and in vivo. The progression of thrombosis and stroke was evaluated after treatment with rivaroxaban or PBS. Nuclear factor-κB (NF-κB) signaling pathway in venous endothelial cells and in the rat model of deep venous thrombus was assessed. The therapeutic effects of rivaroxaban were evaluated as determined by changes in deep venous thrombosis in the rat model. Our results showed that rivaroxaban markedly inhibited TAFI and PAI-1 expression levels, neutrophils, tissue factor, neutrophil extracellular traps (NETs), myeloperoxidase and macrophages in venous endothelial cells and in the rat model of deep venous thrombus. Expression levels of ADP, PAIs, von Willebrand factor (vWF) and thromboxane were downregulated in vein endothelial cells and in serum from the experimental rats. Importantly, the incidences of inferior vena cava filter thrombus were protected by rivaroxaban during heparin-induced thrombolysis deep venous thrombosis in the rat model. We observed that activity of the NF-κB signaling pathway was inhibited by rivaroxaban in vein endothelial cells both in vitro and in vivo. Notably, immunohistology indicated that rivaroxaban attenuated deep venous thrombosis and the

Occluded Brescia-Cimino Hemodialysis Fistulas: Endovascular Treatment with Both Brachial Arterial and Venous Access Using the Pull-Through Technique

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

Miyayama, Shiro; Matsui, Osamu; Taki, Keiichi

2005-12-15

We retrospectively evaluated the usefulness of both arterial and venous access with the pull-through technique in endovascular treatment of totally occluded Brescia-Cimino fistulas. We treated 26 patients (17 men, 9 women; age range 43-82 years, mean age 66 years) with occluded Brescia-Cimino fistulas. First, the occluded segment was traversed from the antegrade brachial arterial access using a microcatheter-guidewire system. Second, the vein was retrogradely punctured after confirmation of all diseased segments, and a 0.014- or 0.016-inch guidewire was pulled through the venous access when the occluded segment was long. All interventions including thrombolysis, thromboaspiration, angioplasty, and stent placement were performedmore » via the venous access. The occlusion was successfully crossed via the brachial arterial access in 23 patients (88%). In 2 patients it was done from the venous approach. In the remaining patient it was not possible to traverse the occluded segment. The pull-through technique was successful in all 19 attempts. Clinical success was achieved in 96%, the primary patency rates at 6, 12, and 18 months were 83%, 78%, and 69%, the primary assisted patency rates were 92%, 92%, and 72%, and the secondary patency rates were 92%, 92%, and 92%, respectively. Minor complications in 5 patients included venous perforation in 2 (8%), venous rupture in 1 (4%), and regional hematoma in 2 (8%). Our study suggests that endovascular treatments with both arterial and venous access using the pull-through technique are highly effective in restoring function in totally occluded Brescia-Cimino fistulas.« less

Peripheral Venous Access Ports: Outcomes Analysis in 109 Patients

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

Bodner, Leonard J.; Nosher, John L.; Patel, Kaushik M.

significant (p = 0.6). Aspiration occlusion occurred in 13 patients (11.7%). Intracatheter urokinase was infused in eight of these patients and successfully restored catheter function in all but two instances. These complication rates are comparable to or better than those reported with chest ports.Conclusion: Peripheral ports for long-term central venous access placed by interventional radiologists in the interventional radiology suite are as safe and as effective as chest ports.« less

Air embolism after central venous catheterization.

PubMed

Kashuk, J L; Penn, I

1984-09-01

Air embolism--the most dangerous complication of central venous catheterization--may occur in several ways. The most frequent is from disconnection of the catheter from the related intravenous tubing. An embolism may present with a sucking sound, tachypnea, air hunger, wheezing, hypotension and a "mill wheel" murmur. A later manifestation is severe pulmonary edema. In a review of 24 patients, the mortality was 50 per cent. Among the survivors, five (42 per cent) had neurologic damage. Immediate treatment includes placing the patient in the left lateral and Trendelenberg positions, administration of oxygen and aspiration of air from the heart. Cardiac massage and emergency cardiopulmonary bypass may be necessary. Most instances can be prevented by inserting the cannula with the patient in the Trendelenberg position, occluding the cannula hub except briefly while the catheter is inserted, fixation of the catheter hub to its connections and occlusive dressing over the track after removal of the catheter.

[Superior vena cava syndrome unrelated to central venous catheter in a patient on chronic hemodialysis].

PubMed

Veronesi, Marco; Mancini, Elena; Salvati, Filippo; Santoro, Antonio

2011-01-01

A 67-year-old woman with end-stage renal disease (polycystic kidney disease) who had been on dialysis for 10 years came to our department for a second opinion about upper left arm edema homolateral to the arteriovenous fistula (AVF). Because of the suspicion of venous stenosis she had already been submitted to angiographic examination of the AVF which, however, did not show any occlusive process. In addition to the kidney problem, the clinical history included dilated cardiomyopathy, and 2 years earlier a biventricular implantable cardioverter defibrillator (ICD) had been placed. The patient had never had a central venous catheter (CVC). She presented a typical superior vena cava syndrome picture with arm, neck and hemifacial edema and superficial cutaneous venous reticulum. The venous pressure during extracoroporeal circulation was high and blood recirculation was documented. Angio-CT was performed to look for a compressive process in the chest, but this was excluded. We then performed a new trans-AVF angiography to study extensively the axillary-subclavian-superior vena cava district. At first, no stenosis or thrombosis was observed, but the presence of ICD and its leads (left-sided implanted) in the anonymous vein created obstacles to diagnosis. Repeated injections of contrast medium and focusing imaging on the leads route allowed us to highlight a venous stenosis in the anonymous vein. Transluminal angioplasty was successfully carried out during the same procedure. 1) In hemodialysis patients the appearance of signs of intrathoracic vein drainage obstacles is not always associated with previous CVC implantation; 2) in the hemodialysis patient, any device (PM, ICD) should be implanted contralaterally to the fistula arm in order to avoid the risk that a venous stenosis may cause AVF dysfunction.

Defining degree of aortic occlusion for partial-REBOA: A computed tomography study on large animals.

PubMed

Reva, Viktor A; Matsumura, Yosuke; Samokhvalov, Igor M; Pochtarnik, Alexander A; Zheleznyak, Igor S; Mikhailovskaya, Ekaterina M; Morrison, Jonathan J

2018-04-20

Partial resuscitative endovascular balloon occlusion of the aorta (P-REBOA) is a modified REBOA technique designed to help ameliorate ischemia-reperfusion injury. The balloon is partially deflated, allowing a proportion of aortic flow distal to the balloon. The aim of this study is to use an ovine model of haemorrhagic shock to correlate the degree of occlusion to several hemodynamic indices. Six sheep weighing 35-46 kg underwent a controlled venous haemorrhage inside a CT scanner until the systolic arterial pressure (AP) dropped to <90 mmHg. A balloon positioned in an aortic zone I was incrementally filled with 1 mL of saline, with serial measurement of the proximal (carotid artery) and distal (femoral artery) mean APs (MAP) and intra-balloon pressure (IBP), along with CT imaging, following each inflation, until full occlusion was achieved. A diameter of the aorta at zone I was 16.0 (15.7-17.2) mm, with a cross-sectional area of 212 (194-233) mm 2 . Median volume of saline injected into the balloon until total occlusion was 7.0 (6.3-8.5) mL. During gradual balloon inflation, proximal MAP increased and distal MAP decreased proportionate to the degree of occlusion, in a linear fashion (proximal: r 2  = 0.85, p < 0.001; distal: r 2  = 0.95, p < 0.001). The femoral/carotid (F/C) pressure gradient also demonstrated a linear trend (r 2  = 0.90, p < 0.001). The relationship between percentage occlusion and IBP was sigmoid. MAP values became significantly different at 40-49% occlusion and more (p < 0.01). Furthermore, a drop in the distal pulse pressure from 7.0 (5.5-16.5) to 2.0 (1.5-5.0) mmHg was observed at 80% occlusion. All animals had femoral pulse pressure <5 mmHg at 80% of occlusion and more, which also coincided with the observed loss of pulsatility of the femoral wave-form. Serial CT angiography at an ovine model of haemorrhagic shock demonstrates a correlation between the femoral MAP, F/C pressure gradient and degree of zone

Thromboembolic Risk of Endovascular Intervention for Lower Extremity Deep Venous Thrombosis.

PubMed

Lindsey, Philip; Echeverria, Angela; Poi, Mun J; Matos, Jesus; Bechara, Carlos F; Cheung, Mathew; Lin, Peter H

2018-05-01

This study evaluated the risk of thromboembolism during endovascular interventions in patients with symptomatic lower extremity deep vein thrombosis (DVT) METHODS: Clinical records of all patients who underwent endovascular interventions for symptomatic lower extremity DVT from 2001 to 2017 were retrospectively analyzed using a prospectively maintained database. Only patients who received an inferior vena cava (IVC) filter were included in the analysis. Trapped intrafilter thrombus was assessed for procedure-related thromboembolism. Clinical outcomes of thrombus management and thromboembolism risk were analyzed. A total 172 patients (mean age 57.4 years, 98 females) who underwent 174 endovascular DVT interventions were included in the analysis. Treatment strategies included thrombolytic therapy (64%), mechanical thrombectomy (n = 86%), pharmacomechanical thrombolysis (51%), balloon angioplasty (98%), and stent placement (28%). Thrombectomy device used included AngioJet (56%), Trellis (19%), and Aspire (11%). Trapped IVC filter thrombus was identified in 58 patients (38%) based on the IVC venogram. No patient developed clinically evident pulmonary embolism (PE). IVC filter retrieval was performed in 98 patients (56%, mean 11.8 months after implantation). Multivariate analysis showed that iliac vein occlusion (P = 0.04) was predictive for procedure-related thromboembolism. Iliac vein thrombotic occlusion is associated with an increased thromboembolic risk in DVT intervention. Retrievable IVC filter should be considered when performing percutaneous thrombectomy in patients with iliac venous occlusion to prevent PE. Copyright © 2017 Elsevier Inc. All rights reserved.

Selective tissue factor/factor VIIa Inhibitor, ER-410660, and its prodrug, E5539, have anti-venous and anti-arterial thrombotic effects with a low risk of bleeding.

PubMed

Nagakura, Tadashi; Tabata, Kimiyo; Kira, Kazunobu; Hirota, Shinsuke; Clark, Richard; Matsuura, Fumiyoshi; Hiyoshi, Hironobu

2013-08-01

Many anticoagulant drugs target factors common to both the intrinsic and extrinsic coagulation pathways, which may lead to bleeding complications. Since the tissue factor (TF)/factor VIIa complex is associated with thrombosis onset and specifically activates the extrinsic coagulation pathway, compounds that inhibit this complex may provide therapeutic and/or prophylactic benefits with a decreased risk of bleeding. The in vitro enzyme profile and anticoagulation selectivity of the TF/VIIa complex inhibitor, ER-410660, and its prodrug E5539 were assessed using enzyme inhibitory and plasma clotting assays. In vivo effects of ER-410660 and E5539 were determined using a TF-induced, thrombin generation rhesus monkey model; a stasis-induced, venous thrombosis rat model; a photochemically induced, arterial thrombosis rat model; and a rat tail-cut bleeding model. ER-410660 selectively prolonged prothrombin time, but had a less potent anticoagulant effect on the intrinsic pathway. It also exhibited a dose-dependent inhibitory effect on thrombin generation caused by TF-injection in the rhesus monkey model. ER-410660 also reduced venous thrombus weights in the TF-administered, stasis-induced, venous thrombosis rat model and prolonged the occlusion time induced by arterial thrombus formation after vascular injury. The compound was capable of doubling the total bleeding time in the rat tail-cut model, albeit with a considerably higher dose compared to the effective dose in the venous and arterial thrombosis models. Moreover, E5539, an orally available ER-410660 prodrug, reduced the thrombin-anti-thrombin complex levels, induced by TF-injection, in a dose-dependent manner. Selective TF/VIIa inhibitors have potential as novel anticoagulants with a lower propensity for enhancing bleeding. Copyright © 2013 Elsevier Ltd. All rights reserved.

Venous thromboembolism after major venous injuries: Competing priorities.

PubMed

Frank, Brian; Maher, Zoё; Hazelton, Joshua P; Resnick, Shelby; Dauer, Elizabeth; Goldenberg, Anna; Lubitz, Andrea L; Smith, Brian P; Saillant, Noelle N; Reilly, Patrick M; Seamon, Mark J

2017-12-01

Venous thromboembolism (VTE) after major vascular injury (MVI) is particularly challenging because the competing risk of thrombosis and embolization after direct vessel injury must be balanced with risk of bleeding after surgical repair. We hypothesized that venous injuries, repair type, and intraoperative anticoagulation would influence VTE formation after MVI. A multi-institution, retrospective cohort study of consecutive MVI patients was conducted at three urban, Level I centers (2005-2013). Patients with MVI of the neck, torso, or proximal extremities (to elbows/knees) were included. Our primary study endpoint was the development of VTE (DVT or pulmonary embolism [PE]). The 435 major vascular injury patients were primarily young (27 years) men (89%) with penetrating (84%) injuries. When patients with (n = 108) and without (n = 327) VTE were compared, we observed no difference in age, mechanism, extremity injury, tourniquet use, orthopedic and spine injuries, damage control, local heparinized saline, or vascular surgery consultation (all p > 0.05). VTE patients had greater Injury Severity Score (ISS) (17 vs. 12), shock indices (1 vs. 0.9), and more torso (58% vs. 35%) and venous (73% vs. 48%) injuries, but less often received systemic intraoperative anticoagulation (39% vs. 53%) or postoperative enoxaparin (47% vs. 61%) prophylaxis (all p < 0.05). After controlling for ISS, hemodynamics, injured vessel, intraoperative anticoagulation, and postoperative prophylaxis, multivariable analysis revealed venous injury was independently predictive of VTE (odds ratio, 2.7; p = 0.002). Multivariable analysis of the venous injuries subset (n = 237) then determined that only delay in starting VTE chemoprophylaxis (odds ratio, 1.3/day; p = 0.013) independently predicted VTE after controlling for ISS, hemodynamics, injured vessel, surgical subspecialty, intraoperative anticoagulation, and postoperative prophylaxis. Overall, 3.4% of venous injury patients developed PE, but PE

Neural substrates of dynamic object occlusion.

PubMed

Shuwairi, Sarah M; Curtis, Clayton E; Johnson, Scott P

2007-08-01

In everyday environments, objects frequently go out of sight as they move and our view of them becomes obstructed by nearer objects, yet we perceive these objects as continuous and enduring entities. Here, we used functional magnetic resonance imaging with an attentive tracking paradigm to clarify the nature of perceptual and cognitive mechanisms subserving this ability to fill in the gaps in perception of dynamic object occlusion. Imaging data revealed distinct regions of cortex showing increased activity during periods of occlusion relative to full visibility. These regions may support active maintenance of a representation of the target's spatiotemporal properties ensuring that the object is perceived as a persisting entity when occluded. Our findings may shed light on the neural substrates involved in object tracking that give rise to the phenomenon of object permanence.

Effects of Hypothermic Cardiopulmonary Bypass on Internal Jugular Bulb Venous Oxygen Saturation, Cerebral Oxygen Saturation, and Bispectral Index in Pediatric Patients Undergoing Cardiac Surgery: A Prospective Study.

PubMed

Hu, Zhiyong; Xu, Lili; Zhu, Zhirui; Seal, Robert; McQuillan, Patrick M

2016-01-01

The objective of this study was to evaluate the effect of hypothermic cardiopulmonary bypass (CPB) on cerebral oxygen saturation (rSO2), internal jugular bulb venous oxygen saturation (SjvO2), mixed venous oxygen saturation (SvO2), and bispectral index (BIS) used to monitor cerebral oxygen balance in pediatric patients.Sixty American Society of Anesthesiologists Class II-III patients aged 1 to 4 years old with congenital heart disease scheduled for elective cardiac surgery were included in this study. Temperature, BIS, rSO2, mean arterial pressure, central venous pressure, cerebral perfusion pressure (CPP), and hematocrit were recorded. Internal jugular bulb venous oxygen saturation and SvO2 were obtained from blood gas analysis at the time points: after induction of anesthesia (T0), beginning of CPB (T1), ascending aortic occlusion (T2), 20 minutes after initiating CPB (T3), coronary reperfusion (T4), separation from CPB (T5), and at the end of operation (T6). The effect of hypothermia or changes in CPP on rSO2, SjvO2, SvO2, and BIS were analyzed.Compared with postinduction baseline values, rSO2 significantly decreased at all-time points: onset of extracorporeal circulation, ascending aortic occlusion, 20 minutes after CPB initiation, coronary reperfusion, and separation from CPB (P < 0.05). Compared with measurements made following induction of anesthesia, SjvO2 significantly increased with initiation of CPB, ascending aortic occlusion, 20 minutes after initiating CPB, coronary reperfusion, and separation from CPB (P < 0.05). Compared with induction of anesthesia, BIS significantly decreased with the onset of CPB, aortic cross clamping, 20 minutes after initiating CPB, and coronary reperfusion (P < 0.05). Bispectral index increased following separation from CPB. There was no significant change in SvO2 during cardiopulmonary bypass (P > 0.05). Correlation analysis demonstrated that rSO2 was positively related to CPP (r = 0.687, P = 0

One-step reconstruction of the right inferior hepatic veins using auto-venous grafts in living-donor liver transplantation.

PubMed

Ikegami, Toru; Shirabe, Ken; Yoshiya, Shohei; Soejima, Yuji; Yoshizumi, Tomoharu; Uchiyama, Hideaki; Toshima, Takeo; Motomura, Takashi; Maehara, Yoshihiko

2013-07-01

Reconstruction of the right inferior hepatic vein (RIHV) presents a major technical challenge in living donor liver transplantation (LDLT) using right lobe grafts. We studied 47 right lobe LDLT grafts with RIHV revascularization, comparing one-step reconstruction, performed post-May 2007 (n = 16), with direct anastomosis, performed pre-May 2007 (n = 31). In the one-step reconstruction technique, the internal jugular vein (n = 6), explanted portal vein (n = 5), inferior vena cava (n = 3), and shunt vessels (n = 2) were used as venous patch grafts for unifying the right hepatic vein, RIHVs, and middle hepatic vein tributaries. By 6 months after LDLT, there was no case of occlusion of the reconstructed RIHVs in the one-step reconstruction group, but a cumulative occlusion rate of 18.2 % in the direct anastomosis group. One-step reconstruction required a longer cold ischemic time (182 ± 40 vs. 115 ± 63, p < 0.001) and these patients had higher alanine transaminase values (142 ± 79 vs. 96 ± 46 IU/L, p = 0.024) on postoperative day POD 7. However, the 6-month short-term graft survival rates were 100 % with one-step reconstruction and 83.9 % with direct anastomosis, respectively. One-step reconstruction of the RIHVs using auto-venous grafts is an easy and feasible technique promoting successful right lobe LDLT.

Microfluidics for investigating vaso-occlusions in sickle cell disease.

PubMed

Horton, Renita E

2017-07-01

SCD stems from amutation in the beta globin gene. Upon deoxygenation, hemoglobin polymerizes and triggers RBC remodeling. This phenomenon is central to SCD pathogenesis as individuals suffering from the disease are plagued by painful vaso-occlusive crises episodes. These episodes are the result of a combination of processes including inflammation, thrombosis, and blood cell adhesion to the vascular wall which leads to blockages within the vasculature termed vaso-occlusions. Vaso-occlusive episodes deprive tissues of oxygen and are a major contributor to SCD-related complications; unfortunately, the complex mechanisms that contribute to vaso-occlusions are not well understood. Vaso-occlusions can occur in post-capillary venules; hence, the microvasculature is a prime target for SCD therapies. Traditional in vitro systems poorly recapitulate architectural and dynamic flow properties of in vivo systems. However, microfluidic devices can capture features of the native vasculature such as cellular composition, flow, geometry, and ECM presentation. This review, although not comprehensive, highlights microfluidic approaches that aim to improve our current understanding of the pathophysiological mechanisms surrounding SCD. Microfluidic platforms can aid in identifying factors that may contribute to disease severity and can serve as suitable test beds for novel treatment strategies which may improve patient outcomes. © 2017 John Wiley & Sons Ltd.

Simultaneous total occlusion of two coronary arteries associated with use of drospirenone-ethinyl estradiol (oral contraceptive).

PubMed

Atmaca, Hüsnü; Köprülü, Diyar; Kiriş, Tuncay; Zeren, Gönül; Şahin, İrfan

2018-01-01

Although the use of oral contraceptives is associated with an increased risk of venous thromboembolic disease, the risk of myocardial infarction (MI) is unclear. A new, third-generation contraceptive agent, drospirenone-ethinyl estradiol, which contains less estrogen and a new progestogen, drospirenone, in a different combination, has been considered more reliable in terms of risk of MI. However, there have been some cases of MI associated with the use of drospirenone-ethinyl estradiol, despite the protective effects of this oral contraceptive. In this report, a 33-year-old woman who had used drospirenone-ethinyl estradiol for 6 months was admitted with MI and symptoms of cardiogenic shock. Coronary angiography revealed the total occlusion of 2 coronary arteries and so percutaneous coronary intervention was performed. To the best of our knowledge, this is the first case report of simultaneous total occlusion of 2 coronary arteries associated with the use of drospirenone-ethinyl estradiol in the English-language medical literature.

Future prospects for contact factors as therapeutic targets

PubMed Central

Gailani, David

2015-01-01

Anticoagulants currently used in clinical practice to treat or prevent thromboembolic disease are effective, but place patients at increased risk for serious bleeding because they interfere with plasma enzymes (thrombin and factor Xa) that are essential for hemostasis. In the past 10 years, work with genetically altered mice and studies in baboons and rabbits have demonstrated that the plasma contact proteases factor XI, factor XII, and prekallikrein contribute to the formation of occlusive thrombi despite having limited roles in hemostasis. In the case of factor XI, epidemiologic data from human populations indicate that elevated levels of this protein increase risk for stroke and venous thromboembolism and may also influence risk for myocardial infarction. These findings suggest that inhibiting contact activation may produce an antithrombotic effect without significantly compromising hemostasis. This chapter reviews strategies that are being developed for therapeutic targeting of factor XI and factor XII and their performances in preclinical and early human trials. PMID:25696834

Optimization of the static occlusion by "occlusal surface settling" in the Cerec 3D software.

PubMed

Späth, C; Kordass, B

2006-04-01

The adjustment of the static occlusion can be automated in computer-based systems. The Cerec 3D software makes it possible to take preformed occlusal surfaces from a database and adapt them to the antagonist. In this adaptation (settling), the CAD occlusal surface "settles" as whole or each cusp individually into the occlusal surface of the antagonist until stable occlusion is reached. Two occlusal surface shapes were compared: Vita Physiodens and Lee Culp. An index was formed from the number, quality, and position of the occlusal contacts for 35 model cases (25 molars, 10 premolars). With regard to the settling of the total occlusal surfaces, there were no differences between the two occlusal surface shapes. In "cusp settling" of the molars, Vita Physiodens performed significantly better. In the comparison of the 1st with the 3rd settling process, significant improvements occurred the 3rd time in many cases when settling individual cusps, but in clearly fewer cases in the settling process of the total occlusal surface. The Lee Culp tooth occlusion improved especially after the 3rd settling process of individual cusps. It is therefore expedient to combine both settling versions with one another.

Retinal oximetry during treatment of retinal vein occlusion by ranibizumab in patients with high blood pressure and dyslipidemia.

PubMed

Keilani, C; Halalchi, A; Wakpi Djeugue, D; Regis, A; Abada, S

2016-12-01

In the present study, we examined retinal vascular oxygen saturation in patients with retinal vein occlusion (RVO), high blood pressure (HBP) and dyslipidemia, before and during intravitreal vascular endothelial growth factor (VEGF) injection (ranibizumab). We retrospectively reviewed the medical records of six patients with visual acuity (VA) reduced by macular edema (ME) secondary to RVO with HBP and dyslipidemia, who underwent intravitreal anti-VEGF injection between October 2014 and February 2015 in the department of ophthalmology of François-Quesnay Hospital at Mantes-la-Jolie (France). The main inclusion criterion was the presence of RVO with ME and decreased VA. The primary endpoint was improvement of retinal venous oxygen saturation in patients with RVO before and 3 months after intravitreal ranibizumab injection. Secondary outcomes were improvement of retinal arterial oxygen saturation, improvement of best-corrected visual acuity (BCVA) on the Early Treatment Diabetic Retinopathy Study (ETDRS) scale, regression of ME measured by the central macular thickness (CMT) in nm and studying the correlation between blood pressure (BP) and retinal venous oxygen saturation before and after ranibizumab. Six eyes of six patients were included. Before treatment, the mean (standard deviation [SD]) of the retinal venous saturation (%) was 38.1±14.2. Three months after the injections, the mean (SD) of the retinal venous saturation (%) increased statistically significantly 49.2±11 (P=0.03). In this study, retinal venous oxygen saturation in patients with RVO, HBP and dyslipidemia was partially normalized during intravitreal ranibizumab treatment. Copyright © 2016 Elsevier Masson SAS. All rights reserved.

Reduced Intimal Hyperplasia in Rabbits via Medical Therapy after Carotid Venous Bypass

PubMed Central

Yucel, Semih; Bahcivan, Muzaffer; Gol, Mehmet Kamil; Erenler, Behice H.; Kolbakir, Fersat; Keceligil, Hasan T.

2009-01-01

Intimal hyperplasia is a major cause of restenosis after the interventional or surgical treatment of occlusive arterial disease. We investigated the effects of clopidogrel, calcium dobesilate, nebivolol, and atorvastatin on the development of intimal hyperplasia in rabbits after carotid venous bypass surgery. We divided 40 male New Zealand rabbits into 4 study groups and 1 control group. After occluding the carotid arteries of the rabbits, we constructed jugular venous grafts between the proximal and the distal segments of the occluded artery. Thereafter, group 1 (control) received no medication. We administered daily oral doses of clopidogrel to group 2, calcium dobesilate to group 3, nebivolol to group 4, and atorvastatin to group 5. The rabbits were killed 28 days postoperatively. The arterialized jugular venous grafts were extracted for histopathologic examination. Intimal thicknesses were 42.87 ± 6.95 μm (group 2), 46.5 ± 9.02 μm (group 3), 34.12 ± 5.64 μm (group 4), and 48.37 ± 6.16 μm (group 5), all significantly less than the 95.12 ± 9.93 μm in group 1 (all P < 0.001). Medial thicknesses were 94 ± 6 μm (group 2), 101.5 ± 13.52 μm (group 3), 90.5 ± 9.69 μm (group 4), and 101.37 ± 7.99 μm (group 5), all significantly thinner than the 126.62 ± 13.53 μm in group 1 (all P < 0.001). In our experimental model of carotid venous bypass grafting in rabbits, clopidogrel, calcium dobesilate, nebivolol, and atorvastatin each effectively reduced the development of intimal hyperplasia. Herein, we discuss our findings and review the medical literature. PMID:19876413

Increasing cyanosis early after cavopulmonary connection caused by abnormal systemic venous channels.

PubMed

Gatzoulis, M A; Shinebourne, E A; Redington, A N; Rigby, M L; Ho, S Y; Shore, D F

1995-02-01

To show that abnormal systemic venous channels in patients who undergo cavopulmonary anastomoses can become manifest and haemodynamically important only after surgery despite detailed preoperative investigation. Descriptive study of patients fulfilling the above criteria selected from hospital records over the past three years. A tertiary referral centre. Of the three cases identified, two were isomeric, one with left atrial isomerism and hemiazygos continuation of the inferior vena cava who underwent bilateral bidirectional Glenn anastomoses and one with right isomerism who underwent total cavopulmonary anastomosis. Case 3 had absent left atrioventricular connection with a hypoplastic left lung and underwent a classic right Glenn procedure. All three cases presented with progressive cyanosis in the early postoperative period. Postoperative angiography in case 1 showed a remnant of a left inferior vena cava draining to the atrium to have become grossly dilated causing cyanosis, which resolved after redirection of this vessel and of the hepatic veins into the right pulmonary artery with an intra-atrial baffle. Cyanosis in case 2 was caused by intra-hepatic shunting to a hepatic vein draining to the left of the intra-atrial baffle. The diagnosis was made at necropsy, being overlooked on postoperative angiography. Repeat angiography in case 3 showed progressive dilatation of a small left superior vena cava to coronary sinus. Test occlusion with a view to embolisation revealed hitherto an undemonstrated hemiazygos continuation of inferior caval to brachiocephalic vein. The patient underwent surgical ligation of these two venous channels. Despite appropriate investigation some "abnormal" venous pathways manifest themselves, dilate, and become haemodynamically important only after surgical cavopulmonary anastomoses. In the presence of early postoperative cyanosis "new" systemic venous collateral channels should be considered as a possible cause, which may require

Analysis of decrease in lung perfusion blood volume with occlusive and non-occlusive pulmonary embolisms.

PubMed

Ikeda, Yohei; Yoshimura, Norihiko; Hori, Yoshiro; Horii, Yosuke; Ishikawa, Hiroyuki; Yamazaki, Motohiko; Noto, Yoshiyuki; Aoyama, Hidefumi

2014-12-01

The aim of this study was to determine if lung perfusion blood volume (lung PBV) with non-occlusive pulmonary embolism (PE) differs quantitatively and visually from that with occlusive PE and to investigate if lung PBV with non-occlusive PE remains the same as that without PE. Totally, 108 patients suspected of having acute PE underwent pulmonary dual-energy computed tomography angiography (DECTA) between April 2011 and January 2012. Presence of PE on DECTA was evaluated by one radiologist. Two radiologists visually evaluated the PE distribution (segmental or subsegmental) and its nature (occlusive or non-occlusive) on DECTA and classified perfusion in lung PBV as "decreased," "slightly decreased," and "preserved". Two radiologists used a lung PBV application to set a region of interest (ROI) in the center of the lesion and measured HU values of an iodine map. In the same slice as the ROI of the lesion and close to the lesion, another ROI was set in the normal perfusion area without PE, and HUs were measured. The proportion of lesions was compared between the occlusive and non-occlusive groups. HUs were compared among the occlusive, non-occlusive, and corresponding normal groups. Twenty-five patients had 80 segmental or subsegmental lesions. There were 37 and 43 lesions in the occlusive and non-occlusive groups, respectively. The proportion of decreased lesions was 73.0% (27/37) in the occlusive group, while that of preserved lesions in the non-occlusive group was 76.7% (33/43). There was a significant difference in the proportion of lesions (P<0.001) between the two groups. HUs of the iodine map were significantly higher in the non-occlusive group than in the occlusive group (33.8 ± 8.2 HU vs. 11.9 ± 6.1 HU, P<0.001). There was no significant difference in HUs for the entire lesion between the non-occlusive (33.8 ± 8.2 HU) and corresponding normal group (34.5 ± 6.8 HU; P=0.294). Iodine perfusion tended to be visually and quantitatively preserved in lungs with

Combined branch retinal vein and artery occlusion in toxoplasmosis.

PubMed

Aggio, Fabio Bom; Novelli, Fernando José de; Rosa, Evandro Luis; Nobrega, Mário Junqueira

2016-01-01

A 22-year-old man complained of low visual acuity and pain in his left eye for five days. His ophthalmological examination revealed 2+ anterior chamber reaction and a white, poorly defined retinal lesion at the proximal portion of the inferotemporal vascular arcade. There were retinal hemorrhages in the inferotemporal region extending to the retinal periphery. In addition, venous dilation, increased tortuosity, and ischemic retinal whitening along the inferotemporal vascular arcade were also observed. A proper systemic work-up was performed, and the patient was diagnosed with ocular toxoplasmosis. He was treated with an anti-toxoplasma medication, and his condition slowly improved. Inferior macular inner and middle retinal atrophy could be observed on optical coherence tomography as a sequela of ischemic injury. To our knowledge, this is the first report of combined retinal branch vein and artery occlusion in toxoplasmosis resulting in a striking and unusual macular appearance.

Treatment and follow-up of venous thrombosis in the neonatal intensive care unit: A retrospective study

PubMed Central

Bohnhoff, James C.; DiSilvio, Stefanie A.; Aneja, Rajesh K.; Shenk, Jennifer R.; Domnina, Yuliya A.; Brozanski, Beverly S.; Good, Misty

2016-01-01

Objective The critically ill, premature patients of neonatal intensive care units are susceptible to venous thrombosis, an adverse event associated with short- and long-term morbidity. Venous thrombosis is frequently treated with low molecular weight heparins (LMWH) such as enoxaparin, but optimal dosing of LMWH must balance the morbidity of venous thrombosis with the potential adverse affects of anticoagulation. The optimal dosing of enoxaparin for premature infants is unclear. The objective of this study was to describe enoxaparin therapy and follow-up in critically ill neonates diagnosed with venous thrombosis. Study Design Retrospective medical record review in the neonatal intensive care unit (NICU) in a single tertiary care institution. Infants with venous thrombosis diagnosed in the NICU were identified using pre-existing quality improvement lists and medical records. Results Twenty-six infants with 30 venous thromboses were identified with a median gestational age of 31 weeks at birth. Eighteen (69%) infants received enoxaparin for venous thrombosis during their hospitalization, beginning with a median dose of 1.5 mg/kg every 12h. This dose was increased to a median 2.1 mg/kg every 12h to achieve target anti-factor Xa levels. The target dose was significantly higher in patients with a postmenstrual age less than 37 weeks. Enoxaparin treatment was documented after discharge in 12 patients, continuing for a median of 99 days. Four patients died during hospitalization and their deaths were not attributable to venous thrombosis or anticoagulation complication. Follow-up documentation between 6 and 24 months after venous thrombosis diagnosis revealed no major morbidity of venous thrombosis or enoxaparin therapy. Conclusions Our data reinforces the relative safety and necessity of enoxaparin doses above 1.5 mg/kg per 12 hours in most neonates. This was particularly true for infants at lower postmenstrual age. PMID:27906197

Effect of occlusion amblyopia after prescribed full-time occlusion on long-term visual acuity outcomes.

PubMed

Longmuir, Susannah; Pfeifer, Wanda; Scott, William; Olson, Richard

2013-01-01

To investigate the incidence and characteristics of occlusion amblyopia with prescribed full-time patching and determine its effect on long-term visual acuity outcomes. The records of patients younger than 10 years diagnosed as having amblyopia between 1970 and 2000 were retrospectively reviewed. Patients were prescribed full-time occlusion and observed until completion of therapy. Of 597 patients treated for amblyopia by full-time patching, 115 were diagnosed as having occlusion amblyopia (19.3%). Seventy-five percent (86 of 115) developed occlusion amblyopia during the first episode of full-time patching. Occlusion amblyopia occurred more frequently in children prescribed full-time patching at an earlier age (P = .0002), with an odds ratio of 8.56 (95% confidence interval: 2.73, 26.84) in children younger than 36 months and 2.66 (95% confidence interval: 0.96, 7.37) in children between 36 and 59 months old. Seven of the patients with occlusion amblyopia did not reverse fixation and continued to fixate with the initially amblyopic eye after treatment. Final visual acuity in these eyes with occlusion amblyopia was 20/30 or better. After cessation of treatment, the final interocular difference in visual acuity was less in patients with a history of occlusion amblyopia (P = .003). Occlusion amblyopia occurred at all ages, but the incidence decreased with increasing age. Patients who developed occlusion amblyopia with prescribed full-time occlusion had less interocular visual acuity difference than patients who did not, suggesting that development of occlusion amblyopia can indicate the potential for the development of better vision in the originally amblyopic eye. Copyright 2013, SLACK Incorporated.

Effects of Hypothermic Cardiopulmonary Bypass on Internal Jugular Bulb Venous Oxygen Saturation, Cerebral Oxygen Saturation, and Bispectral Index in Pediatric Patients Undergoing Cardiac Surgery: A Prospective Study

PubMed Central

Hu, Zhiyong; Xu, Lili; Zhu, Zhirui; Seal, Robert; McQuillan, Patrick M.

2016-01-01

Abstract The objective of this study was to evaluate the effect of hypothermic cardiopulmonary bypass (CPB) on cerebral oxygen saturation (rSO2), internal jugular bulb venous oxygen saturation (SjvO2), mixed venous oxygen saturation (SvO2), and bispectral index (BIS) used to monitor cerebral oxygen balance in pediatric patients. Sixty American Society of Anesthesiologists Class II-III patients aged 1 to 4 years old with congenital heart disease scheduled for elective cardiac surgery were included in this study. Temperature, BIS, rSO2, mean arterial pressure, central venous pressure, cerebral perfusion pressure (CPP), and hematocrit were recorded. Internal jugular bulb venous oxygen saturation and SvO2 were obtained from blood gas analysis at the time points: after induction of anesthesia (T0), beginning of CPB (T1), ascending aortic occlusion (T2), 20 minutes after initiating CPB (T3), coronary reperfusion (T4), separation from CPB (T5), and at the end of operation (T6). The effect of hypothermia or changes in CPP on rSO2, SjvO2, SvO2, and BIS were analyzed. Compared with postinduction baseline values, rSO2 significantly decreased at all-time points: onset of extracorporeal circulation, ascending aortic occlusion, 20 minutes after CPB initiation, coronary reperfusion, and separation from CPB (P < 0.05). Compared with measurements made following induction of anesthesia, SjvO2 significantly increased with initiation of CPB, ascending aortic occlusion, 20 minutes after initiating CPB, coronary reperfusion, and separation from CPB (P < 0.05). Compared with induction of anesthesia, BIS significantly decreased with the onset of CPB, aortic cross clamping, 20 minutes after initiating CPB, and coronary reperfusion (P < 0.05). Bispectral index increased following separation from CPB. There was no significant change in SvO2 during cardiopulmonary bypass (P > 0.05). Correlation analysis demonstrated that rSO2 was positively related to CPP (r = 0.687, P�

Incidence of upper limb venous thrombosis associated with peripherally inserted central catheters (PICC).

PubMed

Abdullah, B J J; Mohammad, N; Sangkar, J V; Abd Aziz, Y F; Gan, G G; Goh, K Y; Benedict, I

2005-07-01

The objective of this study was to prospectively determine the incidence of venous thrombosis (VT) in the upper limbs in patients with peripherally inserted central catheters (PICC). We prospectively investigated the incidence of VT in the upper limbs of 26 patients who had PICC inserted. The inclusion criteria were all patients who had a PICC inserted, whilst the exclusion criterion was the inability to perform a venogram (allergies, previous contrast medium reaction and inability of gaining venous access). Both valved and non-valved catheters were evaluated. Prior to removal of the PICC, an upper limb venogram was performed. The number of segments involved with VT were determined. The duration of central venous catheterization was classified as; less than 6 days, between 6 days and 14 days and more than 14 days. VT was confirmed in 38.5% (10/26) of the patients. The majority 85.7% (12/14) were complete occlusive thrombi and the majority of VT only involved one segment. There was no statistical correlation between the site of insertion of the PICC and the location of VT. Neither was there any observed correlation between the occurrence of VT with the patient's history of hypertension, hypercholesterolaemia, coronary artery disease, diabetes mellitus, cardiac insufficiency, smoking or cancer. There was also no statistical correlation with the size of the catheter. In conclusion, PICCs are associated with a significant risk of upper extremity deep vein thrombosis (UEVT).

Venous Ulcers

PubMed Central

Caprini, J.A.; Partsch, H.; Simman, R.

2013-01-01

Venous leg ulcers are the most frequent form of wounds seen in patients. This article presents an overview on some practical aspects concerning diagnosis, differential diagnosis and treatment. Duplex ultrasound investigations are essential to ascertain the diagnosis of the underlying venous pathology and to treat venous refluxes. Differential diagnosis includes mainly other vascular lesions (arterial, microcirculatory causes), hematologic and metabolic diseases, trauma, infection, malignancies. Patients with superficial venous incompetence may benefit from endovenous or surgical reflux abolition diagnosed by Duplex ultrasound. The most important basic component of the management is compression therapy, for which we prefer materials with low elasticity applied with high initial pressure (short-stretch bandages and Velcro-strap devices). Local treatment should be simple, absorbing and not sticky dressings keeping adequate moisture balance after debridement of necrotic tissue and biofilms are preferred. After the ulcer is healed compression therapy should be continued in order to prevent recurrence. PMID:26236636

The complicated role of venous drainage on the survival of arterialized venous flaps

PubMed Central

Weng, Weidong; Zhang, Feng; Zhao, Bin; Wu, Zhipeng; Gao, Weiyang; Li, Zhijie; Yan, Hede

2017-01-01

The arterialized venous flap (AVF) has been gradually popularized in clinical settings; however, its survival is still inconsistent and the role of venous drainage remains elusive. In this study, we aimed to investigate the role of venous drainage on the flap survival of arterialized venous flaps. An arterialized venous flap was outlined symmetrically in the rabbit abdomen. The arterial perfusion flap with a unilateral vascular pedicle was taken as the control group and three other experimental groups (I, II and III) were designed based on the number of drainage veins (n = 1, 2 and 3 in the three groups, respectively). Compared with the control group, significant venous congestion was noted in all the experimental groups and the most severe one was seen in group I; while no statistical difference was observed between groups II and III. Similar results regarding blood perfusion state, epidermal metabolite levels and flap survival status were obtained among the three groups. These findings suggested that venous drainage is vital in the survival of the flap, but unlike in the arterial perfusion flaps, the problem of venous congestion can only be partially solved by increasing the number of draining veins. Further studies are warranted to gain insight into this complicated issue. PMID:28145882

Numeric simulation of occlusal interferences in molars restored with ultrathin occlusal veneers.

PubMed

Magne, Pascal; Cheung, Raymond

2017-01-01

Selecting material for a minimally invasive occlusal veneer reconstruction concept requires an understanding of how stresses are distributed during functional and parafunctional forces. The purpose of this in vitro study was to investigate stress distribution in a maxillary molar restored with ultrathin occlusal veneers and subjected by an antagonistic mandibular molar to clenching and working and nonworking movements. A maxillary first molar was modeled from microcomputed tomography (micro-CT) data, using medical image processing software, stereolithography editing/optimizing software, and finite element software. Simulated ultrathin occlusal veneer materials were used. The mandibular molar antagonist was a solid nondeformable geometric entity. Loads simulated clenching, working, and nonworking movements with loading of 500 N. The values of the maximum principal stress were recorded. In the clenching load situation, maximum tensile stresses were located at the occlusal veneer (52 MPa for composite resin versus 47 MPa for ceramic). In the working movement, significant additional tensile stresses were found on the palatal root (87 MPa for composite resin and 85 MPa for ceramic). In the nonworking movement, tensile stress on the ultrathin occlusal veneer increased to 118 MPa for composite resin and 143 MPa for ceramic veneers. Tensile stress peaks shifted to the mesiobuccal root (75 MPa for composite resin and 74 MPa for ceramic). The topography of stresses generated by the various occlusal interferences were clearly identified. Significant tensile stress concentrations were found within the restoration's occlusal topography and root, with the nonworking interference being the most harmful and also the most revealing of the difference between the composite resin and ceramic ultrathin occlusal veneers. Copyright © 2016 Editorial Council for the Journal of Prosthetic Dentistry. Published by Elsevier Inc. All rights reserved.

The use of indium-111 labeled platelet scanning for the detection of asymptomatic deep venous thrombosis in a high risk population

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

Siegel, R.S.; Rae, J.L.; Ryan, N.L.

Five hundred indium-111 labeled platelet imaging studies (387 donor and 113 autologous) were performed postoperatively in 473 patients who had undergone total hip replacement, total knee replacement, or internal fixation of a hip fracture to detect occult deep venous thrombosis. All patients had been anticoagulated prophylactically with aspirin, warfarin sodium (Coumadin), or dextran. Thirty-four possible cases of proximal deep venous thrombosis were identified in 28 asymptomatic patients. To verify the scan results, 31 venograms were performed in 25 patients (three refused). In 21 of 31 cases, totally occlusive thrombi were detected; in 5 cases, partially occlusive thrombi were detected; inmore » 5 cases, no thrombus was seen. No patient who had a negative scan nor any patient who had a verified positive scan (and received appropriate heparin therapy) subsequently developed symptoms or signs of pulmonary embolism. One hundred forty-one indium study patients also underwent Doppler ultrasonography/impedance plethysmography (Doppler/IPG) as a comparative non-invasive technique. In 137 cases, the results of the indium study and Doppler/IPG studies were congruent. The indium study had no false negative results that were detected by Doppler/IPG. No patient had any clinically evident toxicity. These results suggest that indium-111 labeled platelet scanning is a safe, noninvasive means for identifying DVT in high risk patients.« less

A new imaging technique for retinal vessel oximetry: principles and first clinical results in patients with retinal arterial occlusion and diabetic retinopathy

NASA Astrophysics Data System (ADS)

Hammer, M.; Riemer, T.; Vilser, W.; Gehlert, S.; Schweitzer, D.

2009-02-01

The oxygen saturation of blood inside retinal vessels is an essential measure for the estimation of oxygen supply to the tissue as well as its oxygen consumption. In the current approach, the blood oxygenation is measured by a dual-wavelength technique. Using a fundus camera, equipped with a special dual wavelength transmission filter and a color CCD camera, two monochromatic fundus images at 548 nm and 610 nm were recorded simultaneously. The optical densities of retinal vessels for both wavelengths and their ratio, which is known to be proportional to the oxygen saturation, were calculated. From a health control population, mean arterial and venous oxygen saturations were measured of 98+/-10.1% and 65+/-11.7% with reproducibility of 2.52% and 3.25% respectively. In 10 patients with arterial occlusion, a reduction of the arterial oxygen saturation to 78 +/-17% (mean +/- standard deviation, branch arterial occlusion) and 91+/-11% (central arterial occlusion) respectively was found in the occluded vessel. After 5 days on pentoxifilin therapy, the arterial saturation increased to an average of 93+/-12% or 103 +/-6% respectively. In 70 eyes of 42 patients suffering from diabetic retinopathy, an increase of the venous oxygen saturation with the severity of the retinopathy was found (mild nonproliferative retinopathy: 68.4+/-8.2%, moderate non-proliferative retinopathy: 70.5+/-6.8%, severe non-proliferative retinopathy: 72.4+/-7.6%, proliferative retinopathy 75.7+/-8.3%) due to vessel shunting and diabetic changes of the permeability of vessel walls. These first clinical results demonstrate the ability of an accurate measurement of retinal vessel oxygenation with a very simple setup just requiring a special filter in the illumination path of a fundus camera and dedicated software.

Diagnosis of occlusal dysesthesia utilizing prefrontal hemodynamic activity with slight occlusal interference.

PubMed

Ono, Yumie; Ishikawa, Yu; Munakata, Motohiro; Shibuya, Tomoaki; Shimada, Atsushi; Miyachi, Hideo; Wake, Hiroyuki; Tamaki, Katsushi

2016-11-01

Clinical diagnosis of occlusal dysesthesia (OD), also referred to as phantom bite syndrome, is currently based on the absence of objective occlusal discrepancy despite the persistent complaint of uncomfortable bite sensation. We previously demonstrated that the subjective feeling of occlusal discomfort generated by artificial occlusal interference can be objectively evaluated using prefrontal hemodynamic activity in young healthy individuals. The aim of this study was to investigate whether dental patients with and without OD show distinct prefrontal activity during grinding behavior with an occlusal interference. Six dental patients with OD (OD group) and eight patients without OD (control group) grinded piled occlusal strips placed between their first molars and reported their perception and discomfort thresholds during continuous monitoring of prefrontal hemodynamic activity with a portable functional near-infrared spectroscopy. Although patients without OD showed the typical hemodynamic pattern of increased oxyhemoglobin and reduced deoxyhemoglobin (HHb) concentration, those with OD showed persistent incremental increases of HHb concentration that began at the loading of occlusal strips on their molars before they executed grinding. The intensities of the task-related HHb activities showed statistically significant differences between OD and control groups, particularly at channel 3, arranged over the left frontal pole cortex. When the discrimination criterion was set using the intensity values of channel 3 from both groups, the overall accuracy of the OD discrimination was 92.9%. Although physiological interpretation has yet to be elucidated, the task-related response of an increase in HHb may be a useful neuronal signature to characterize dental patients with OD.

Diagnosis of occlusal dysesthesia utilizing prefrontal hemodynamic activity with slight occlusal interference

PubMed Central

Ishikawa, Yu; Munakata, Motohiro; Shibuya, Tomoaki; Shimada, Atsushi; Miyachi, Hideo; Wake, Hiroyuki; Tamaki, Katsushi

2016-01-01

Clinical diagnosis of occlusal dysesthesia (OD), also referred to as phantom bite syndrome, is currently based on the absence of objective occlusal discrepancy despite the persistent complaint of uncomfortable bite sensation. We previously demonstrated that the subjective feeling of occlusal discomfort generated by artificial occlusal interference can be objectively evaluated using prefrontal hemodynamic activity in young healthy individuals. The aim of this study was to investigate whether dental patients with and without OD show distinct prefrontal activity during grinding behavior with an occlusal interference. Six dental patients with OD (OD group) and eight patients without OD (control group) grinded piled occlusal strips placed between their first molars and reported their perception and discomfort thresholds during continuous monitoring of prefrontal hemodynamic activity with a portable functional near‐infrared spectroscopy. Although patients without OD showed the typical hemodynamic pattern of increased oxyhemoglobin and reduced deoxyhemoglobin (HHb) concentration, those with OD showed persistent incremental increases of HHb concentration that began at the loading of occlusal strips on their molars before they executed grinding. The intensities of the task‐related HHb activities showed statistically significant differences between OD and control groups, particularly at channel 3, arranged over the left frontal pole cortex. When the discrimination criterion was set using the intensity values of channel 3 from both groups, the overall accuracy of the OD discrimination was 92.9%. Although physiological interpretation has yet to be elucidated, the task‐related response of an increase in HHb may be a useful neuronal signature to characterize dental patients with OD. PMID:29744159

Medical management of venous ulcers.

PubMed

Pascarella, Luigi; Shortell, Cynthia K

2015-03-01

Venous disease is the most common cause of chronic leg ulceration and represents an advanced clinical manifestation of venous insufficiency. Due to their frequency and chronicity, venous ulcers have a high socioeconomic impact, with treatment costs accounting for 1% of the health care budget in Western countries. The evaluation of patients with venous ulcers should include a thorough medical history for prior deep venous thrombosis, assessment for an hypercoagulable state, and a physical examination. Use of the CEAP (clinical, etiology, anatomy, pathophysiology) Classification System and the revised Venous Clinical Severity Scoring System is strongly recommended to characterize disease severity and assess response to treatment. This venous condition requires lifestyle modification, with affected individuals performing daily intervals of leg elevation to control edema; use of elastic compression garments; and moderate physical activity, such as walking wearing below-knee elastic stockings. Meticulous skin care, treatment of dermatitis, and prompt treatment of cellulitis are important aspects of medical management. The pharmacology of chronic venous insufficiency and venous ulcers include essentially two medications: pentoxifylline and phlebotropic agents. The micronized purified flavonoid fraction is an effective adjunct to compression therapy in patients with large, chronic ulceration. Copyright © 2015 Elsevier Inc. All rights reserved.

Onyx 18 embolisation of dural arteriovenous fistula via arterial and venous pathways: preliminary experience and evaluation of the short-term outcomes

PubMed Central

Long, X-A; Karuna, T; Zhang, X; Luo, B; Duan, C-Z

2012-01-01

Objective This paper mainly focuses on our preliminary experience and short-term outcome evaluation of embolisation of non-cavernous dural arteriovenous fistulas (ncsDAVFs) and cavernous sinus dural arteriovenous fistulas (csDAVFs) using Onyx 18 (ev3, Plymouth, MN), and in combination with coils, via arterial and venous approaches, respectively. Methods Between August 2008 and March 2010, 21 DAVFs (11 ncsDAVFs and 10 csDAVFs; age range: 28–68 years; 12 females and 9 males) were undertaken. Borden classification showed Type III in 1 and Type II in 10 ncsDAVFs, and Type II in 4 and Type I in 6 csDAVFs. Onyx 18 was used in 11 ncsDAVFs (10 via single feeder and 1 via 2 feeders). Onyx 18 or in combination with coils was used in 10 csDAVFs (9 via the inferior petrosal sinus and 1 via the superior ophthalmic vein). Results Total occlusion in immediate angiography was achieved in 18 cases (85.7%; 10 ncsDAVFs and 8 csDAVFs), and near-total occlusion in 1 ncsDAVF and 2 csDAVFs. Onyx 18 was migrated into normal vasculature in two ncsDAVFs without any sequelae. One csDAVF had VI cranial nerve palsy post-operatively, which completely recovered 2 weeks post-embolisation. Follow-up angiography at 3–12 months showed complete occlusion in 20 cases (95.2%; 10 ncsDAVFs and 10 csDAVFs). One ncsDAVF (4.8%) recurred after 3 months and was successfully re-embolised. Conclusion Preliminary results achieved after embolising 11 ncsDAVFs and 10 csDAVFs using Onyx 18 and in combination with coils via arterial and venous pathways, respectively, appeared to be safe, feasible and effective, as 95.2% of cases were totally occluded without any clinical sequelae. PMID:22374275

Sigmoid sinus occlusion infiltrated by inflammatory myofibroblastic tumor from mastoid.

PubMed

Wang, Jingye; Sun, Zhongwu; Zhuo, Shengxia; Wang, Kai

2015-01-01

Inflammatory myofibroblastic tumor (IMT) and some types of immunoglobulin (Ig) G4-related disease are often involved in the spectrum of inflammatory pseudotumor (IPT) and the concept of IgG4-related IPT/IMT has recently been proposed. A 38-year-old man complained of initial symptoms of blurred vision and headache. A tumor was found in the right mastoid, which caused occlusion of the right sigmoid sinus and intracranial hypertension. A diagnosis of IMT with IgG4+ plasma cell infiltration was established by surgical, pathological, and immunohistochemistry findings. His symptoms were completely relieved after corticosteroid therapy and no recurrence was detected during 22 months of follow-up. A case with cerebral venous sinus infiltrated by IMTs in the head and neck has never been reported; corticosteroid therapy proved satisfactory in IMT with IgG4+ plasma cell infiltration. © 2014 Wiley Periodicals, Inc.

Peripherally Inserted Central Venous Catheters in Pediatric Hematology/Oncology Patients in Tertiary Care Setting: A Developing Country Experience.

PubMed

Fadoo, Zehra; Nisar, Muhammad I; Iftikhar, Raza; Ali, Sajida; Mushtaq, Naureen; Sayani, Raza

2015-10-01

Peripherally inserted central venous catheters (PICC) have been successfully used to provide central access for chemotherapy and frequent transfusions. The purpose of this study was to assess the feasibility of PICCs and determine PICC-related complications in pediatric hematology/oncology patients in a resource-poor setting. All pediatric patients (age below 16 y) with hematologic and malignant disorders who underwent PICC line insertion at Aga Khan University Hospital from January 2008 to June 2010 were enrolled in the study. Demographic features, primary diagnosis, catheter days, complications, and reasons for removal of device were recorded. Total of 36 PICC lines were inserted in 32 pediatric patients. Complication rate of 5.29/1000 catheter days was recorded. Our study showed comparable complication profile such as infection rate, occlusion, breakage, and dislodgement. The median catheter life was found to be 69 days. We conclude that PICC lines are feasible in a resource-poor setting and recommend its use for chemotherapy administration and prolonged venous access.

Venous sinus compromise after pre-sigmoid, transpetrosal approach for skull base tumors: A study on the asymptomatic incidence and report of a rare dural arteriovenous fistula as symptomatic manifestation.

PubMed

Jean, Walter C; Felbaum, Daniel R; Stemer, Andrew B; Hoa, Michael; Kim, H Jeffrey

2017-05-01

The sigmoid sinus is routinely exposed and manipulated during pre-sigmoid, transpetrosal approaches to the skull base, but there is scant data available on the incidence of venous sinus compromise after surgery. We encountered a dural arteriovenous fistula as a result of sigmoid sinus occlusion and examined the incidence of venous sinus thrombosis or narrowing after transpetrosal surgeries. We performed a retrospective analysis of a series of patients treated by the senior surgeons (WCJ, MH, HJK), who underwent either a posterior petrosectomy or translabyrinthine approach for various skull base tumors. All available clinical and radiographic data were thoroughly examined in each patient to determine the post-operative fate of the venous sinuses. Of the 52 available patients, five patients were discovered post-operatively to have a narrowed or constricted sigmoid sinus ipsilateral to the surgery, whereas another five patients were diagnosed with asymptomatic sinus thrombosis either in the transverse or sigmoid or both. None of these patients experienced symptoms, nor were there any instance of ischemic or hemorrhagic complications. However, there was one additional patient who presented with pulsatile tinnitus 2years after surgery. His angiogram showed an occlusion of the ipsilateral sigmoid sinus and a posterior fossa dural arteriovenous fistula. A two-stage transvenous and transarterial embolization was successful in eliminating the fistula. Technical considerations to avoid sinus injuries during pre-sigmoid, transpetrosal surgery are discussed. Copyright © 2017 Elsevier Ltd. All rights reserved.

A New Technique for Femoral Venous Access in Infants Using Arterial Injection Venous Return Guidance

PubMed Central

Ebishima, Hironori; Kitano, Masataka; Kurosaki, Kenichi; Shiraishi, Isao

2017-01-01

Objectives: Although venography guidance is helpful for central venous catheter placement, it is sometimes difficult to place a peripheral intravenous cannula for enhancement. We designed a new technique for establishing femoral venous access using venography guidance in the return phase of peripheral arteriography. This new technique was named arterial injection venous return guidance. Here we assessed the efficacy and safety of arterial injection venous return guidance. Methods: We reviewed data of 29 infants less than 6 months old undergoing catheter intervention at our institute in 2014. Of the 29 patients, femoral venous cannulation was performed using arterial injection venous return guidance in 5 patients, venography in 20 patients, and the landmark method in 4 patients. The technical success rates and incidence of complications were compared. Results: The overall success rates were 100% in the arterial injection venous return-guided and venography-guided groups. The mean procedure duration and mean contrast material injection time were similar between the groups. The contrast effect on the femoral vein in the arterial injection venous return-guided group was lower than that in the venography-guided group, but adequate for surgery. The overall complication rate was 17%, and obstruction of previously placed intravenous catheters was the most common complication. Conclusions: Therefore, the arterial injection venous return guidance technique was as safe and efficient as venography for establishing venous access. PMID:29034015

Proximally pedicled medial plantar flap based on superficial venous system alone for venous drainage.

PubMed

Wright, Thomas C; Mossaad, Bassem M; Chummun, Shaheel; Khan, Umraz; Chapman, Thomas W L

2013-07-01

The proximally pedicled medial plantar flap is well described for coverage of wounds around the ankle and heel. This flap is usually based on the deep venae comitantes for venous drainage, with the superficial veins divided during dissection. Usually any disruption of the deep venous system of the flap would result in abandoning this choice of flap. Venous congestion is a recognised complication of medial plantar flaps. The patient described in this case report had a medial ankle defect with exposed bone, for which a proximally pedicled medial plantar flap was used. As we raised the flap, both venae comitantes of the medial planter artery were found to be disrupted. The flap was raised based on the superficial veins draining into the great saphenous, as the only system for venous drainage, with no evidence of venous congestion. The flap was successfully transposed into the defect and healed with no complications. The proximally pedicled medial plantar flap can safely rely on the superficial venous system alone for drainage. In addition, preserving the superficial veins minimise the risk of venous congestion in this flap. We recommend preservation of superficial venous system when possible. Copyright © 2013 British Association of Plastic, Reconstructive and Aesthetic Surgeons. Published by Elsevier Ltd. All rights reserved.

The predictive value of haemodynamic parameters for outcome of deep venous reconstructions in patients with chronic deep vein obstruction - A systematic review.

PubMed

Kurstjens, Rlm; de Wolf, Maf; Kleijnen, J; de Graaf, R; Wittens, Cha

2017-09-01

Objective The aim of this study was to investigate the predictive value of haemodynamic parameters on success of stenting or bypass surgery in patients with non-thrombotic or post-thrombotic deep venous obstruction. Methods EMBASE, MEDLINE and trial registries were searched up to 5 February 2016. Studies needed to investigate stenting or bypass surgery in patients with post-thrombotic obstruction or stenting for non-thrombotic iliac vein compression. Haemodynamic data needed to be available with prognostic analysis for success of treatment. Two authors, independently, selected studies and extracted data with risk bias assessment using the Quality in Prognosis Studies tool. Results Two studies using stenting and two using bypass surgery were included. Three investigated plethysmography, though results varied and confounding was not properly taken into account. Dorsal foot vein pressure and venous refill times appeared to be of influence in one study, though confounding by deep vein incompetence was likely. Another investigated femoral-central pressure gradients without finding statistical significance, though sample size was small without details on statistical methodology. Reduced femoral inflow was found to be a predictor for stent stenosis or occlusion in one study, though patients also received additional surgery to improve stent inflow. Data on prediction of haemodynamic parameters for stenting of non-thrombotic iliac vein compression were not available. Conclusions Data on the predictive value of haemodynamic parameters for success of treatment in deep venous obstructive disease are scant and of poor quality. Plethysmography does not seem to be of value in predicting outcome of stenting or bypass surgery in post-thrombotic disease. The relevance of pressure-related parameters is unclear. Reduced flow into the common femoral vein seems to be predictive for in-stent stenosis or occlusion. Further research into the predictive effect of haemodynamic parameters is

[Clinical analysis of patients with lower extremity deep venous thrombosis complicated with inferior vena cava thrombus].

PubMed

Dong, Dian-ning; Wu, Xue-jun; Zhang, Shi-yi; Zhong, Zhen-yue; Jin, Xing

2013-06-04

To explore the clinical profiles of patients with lower extremity deep venous thrombosis (DVT) complicated with inferior vena cava (IVC) thrombus and summarize their clinical diagnostic and therapeutic experiences. The clinical characteristics, diagnosis and treatment of 20 hospitalized patients with DVT complicated with inferior vena cava thrombus were analyzed retrospectively. All of them were of proximal DVT. There were phlegmasia cerulea dolens (n = 3), pulmonary embolism (n = 3) and completely occlusion of IVC (n = 5). Clinical manifestations were severe. Retrievable inferior vena cava filter (IVCF) was implanted for 17 cases. Catheter-directed thrombolysis (CDT) through ipsilateral popliteal vein was applied for 7 cases and systemic thrombolysis therapy for 8 cases. The effective rate of thrombolysis for fresh IVC thrombus was 100%. Among 5 cases with Cockett Syndrome, 3 cases underwent balloon dilatation angioplasty and endovascular stenting of iliac vein. And 17 IVCFs were retrieved successfully within 3 weeks. IVC thrombus disappeared completely in 15 cases. Systemic or local thrombolysis with protective IVCF is a safe and effective therapy for nonocclusive IVC thrombus in DVT. And CDT is recommended for symptomatic occlusive IVC thrombus.

Higher complication risk of totally implantable venous access port systems in patients with advanced cancer - a single institution retrospective analysis.

PubMed

Chang, Yi-Fang; Lo, An-Chi; Tsai, Chung-Hsin; Lee, Pei-Yi; Sun, Shen; Chang, Te-Hsin; Chen, Chien-Chuan; Chang, Yuan-Shin; Chen, Jen-Ruei

2013-02-01

Totally implantable port systems are generally recommended for prolonged central venous access in diverse settings, but their risk of complications remains unclear for patients with advanced cancer. The aim of this study was to assess the risk of port system failure in patients with advanced cancer. We conducted a retrospective cohort study in a comprehensive cancer centre. A detailed chart review was conducted among 566 patients with 573 ports inserted during January-June, 2009 (average 345.3 catheter-days). Cox regression analysis was applied to evaluate factors during insertion and early maintenance that could lead to premature removal of the port systems due to infection or occlusion. Port system-related infection was significantly associated with receiving palliative care immediately after implantation (hazard ratio, HR = 7.3, 95% confidence interval, 95% CI = 1.2-46.0), after adjusting for probable confounders. Primary cancer site also impacted the occurrence of device-related infection. Receiving oncologic/palliative care (HR = 3.0, P = 0.064), advanced cancer stage (HR = 6.5, P = 0.077) and body surface area above 1.71 m(2) (HR = 3.4, P = 0.029) increased the risk of port system occlusion. Our study indicates that totally implantable port systems yield a higher risk of complications in terminally ill patients. Further investigation should be carefully conducted to compare outcomes of various central venous access devices in patients with advanced cancer and to develop preventive strategies against catheter failure.

A Review: Proteomics in Retinal Artery Occlusion, Retinal Vein Occlusion, Diabetic Retinopathy and Acquired Macular Disorders.

PubMed

Cehofski, Lasse Jørgensen; Honoré, Bent; Vorum, Henrik

2017-04-28

Retinal artery occlusion (RAO), retinal vein occlusion (RVO), diabetic retinopathy (DR) and age-related macular degeneration (AMD) are frequent ocular diseases with potentially sight-threatening outcomes. In the present review we discuss major findings of proteomic studies of RAO, RVO, DR and AMD, including an overview of ocular proteome changes associated with anti-vascular endothelial growth factor (VEGF) treatments. Despite the severe outcomes of RAO, the proteome of the disease remains largely unstudied. There is also limited knowledge about the proteome of RVO, but proteomic studies suggest that RVO is associated with remodeling of the extracellular matrix and adhesion processes. Proteomic studies of DR have resulted in the identification of potential therapeutic targets such as carbonic anhydrase-I. Proliferative diabetic retinopathy is the most intensively studied stage of DR. Proteomic studies have established VEGF, pigment epithelium-derived factor (PEDF) and complement components as key factors associated with AMD. The aim of this review is to highlight the major milestones in proteomics in RAO, RVO, DR and AMD. Through large-scale protein analyses, proteomics is bringing new important insights into these complex pathological conditions.

Rescue N-butyl-2 cyanoacrylate embolectomy using a Solitaire FR device after venous glue migration during arteriovenous malformation embolization: technical note.

PubMed

Fahed, Robert; Clarençon, Frédéric; Sourour, Nader-Antoine; Chauvet, Dorian; Le Jean, Lise; Chiras, Jacques; Di Maria, Federico

2016-07-01

One of the procedural risks in arteriovenous malformation (AVM) embolization is possible migration of the embolic agent into the venous drainage with an incomplete nidus occlusion, which may lead to severe hemorrhagic complications. This report presents the case of a 29-year-old man who presented with a deep intraparenchymal hematoma on the left side secondary to the spontaneous rupture of a claustral AVM. Upon resorption of the hematoma, the patient underwent an initial therapeutic session of N-butyl-2 cyanoacrylate endovascular embolization, with the purpose of reducing the AVM volume and flow before performing Gamma Knife radiosurgery. After glue injection into one of the arterial feeders, the control angiography showed a partial migration of the glue cast into the straight sinus, with most of the nidus still visible. Because of the bleeding risk due to possible venous hypertension, it was decided to try to retrieve the glue from the vein by using a stent retriever via jugular access. This maneuver allowed a nearly complete removal of the glue cast, thereby restoring normal venous flow drainage. The patient showed no clinical worsening after the procedure. To the authors' knowledge, this is the first report of the use of the Solitaire FR device as a rescue glue retriever. This method should be considered by physicians in cases of unintended glue migration into the venous circulation during AVM embolization.

Imaging Diagnosis of Splanchnic Venous Thrombosis

PubMed Central

Rajesh, S.; Mukund, Amar

2015-01-01

Splanchnic vein thrombosis (SVT) is a broad term that includes Budd-Chiari syndrome and occlusion of veins that constitute the portal venous system. Due to the common risk factors involved in the pathogenesis of these clinically distinct disorders, concurrent involvement of two different regions is quite common. In acute and subacute SVT, the symptoms may overlap with a variety of other abdominal emergencies while in chronic SVT, the extent of portal hypertension and its attendant complications determine the clinical course. As a result, clinical diagnosis is often difficult and is frequently reliant on imaging. Tremendous improvements in vascular imaging in recent years have ensured that this once rare entity is being increasingly detected. Treatment of acute SVT requires immediate anticoagulation. Transcatheter thrombolysis or transjugular intrahepatic portosystemic shunt is used in the event of clinical deterioration. In cases with peritonitis, immediate laparotomy and bowel resection may be required for irreversible bowel ischemia. In chronic SVT, the underlying cause should be identified and treated. The imaging manifestations of the clinical syndromes resulting from SVT are comprehensively discussed here along with a brief review of the relevant clinical features and therapeutic approach. PMID:26600801

Contralateral Occlusion Test: The effect of external ear canal occlusion on hearing thresholds.

PubMed

Reis, Luis Roque; Fernandes, Paulo; Escada, Pedro

Bedside testing with tuning forks may decrease turnaround time and improve decision making for a quick qualitative assessment of hearing loss. The purpose of this study was to quantify the effects of ear canal occlusion on hearing, in order to decide which tuning fork frequency is more appropriate to use for quantifying hearing loss with the Contralateral Occlusion Test. Twenty normal-hearing adults (forty ears) underwent sound field pure tone audiometry with and without ear canal occlusion. Each ear was tested with the standard frequencies. The contralateral ear was suppressed with by masking. Ear occlusion was performed by two examiners. Participants aged between 21 and 30 years (25.6±3.03 years) showed an increase in hearing thresholds with increasing frequencies from 19.94dB (250Hz) to 39.25dB (2000Hz). The threshold difference between occluded and unoccluded conditions was statistically significant and increased from 10.69dB (250Hz) to 32.12dB (2000Hz). There were no statistically significant differences according to gender or between the examiners. The occlusion effect increased the hearing thresholds and became more evident with higher frequencies. The occlusion method as performed demonstrated reproducibility. In the Contralateral Occlusion Test, 256Hz or 512Hz tuning forks should be used for diagnosis of mild hearing loss, and a 2048Hz tuning fork should be used for moderate hearing loss. Copyright © 2017 Elsevier España, S.L.U. and Sociedad Española de Otorrinolaringología y Cirugía de Cabeza y Cuello. All rights reserved.

Management of Cavoatrial Deep Venous Thrombosis: Incorporating New Strategies

PubMed Central

Zayed, Mohamed A.; De Silva, Gayan S.; Ramaswamy, Raja S.; Sanchez, Luis A.

2017-01-01

Cavoatrial deep venous thrombosis (DVT) is diagnosed with increasing prevalence. It can be managed medically with anticoagulation or with directed interventions aimed to efficiently reduce the thrombus burden within the target venous segment. The type of management chosen depends greatly on the etiology and chronicity of the thrombosis, existing patient comorbidities, and the patient's tolerance to anticoagulants and thrombolytic agents. In addition to traditional percutaneous catheter-based pharmacomechanical thrombolysis, other catheter-based suction thrombectomy techniques have emerged in recent years. Each therapeutic modality requires operator expertise and a coordinated care paradigm to facilitate successful outcomes. Open surgical thrombectomy is alternatively reserved for specific patient conditions, including intolerance of anticoagulation, failed catheter-based interventions, or acute emergencies. PMID:28265127

Risk factors for venous thrombosis associated with peripherally inserted central venous catheters

PubMed Central

Pan, Longfang; Zhao, Qianru; Yang, Xiangmei

2014-01-01

To evaluate the risk factors associated with an increased risk of symptomatic peripherally inserted central venous catheter (PICC)-related venous thrombosis. Retrospective analyses identified 2313 patients who received PICCs from 1 January 2012 to 31 December 2013. All 11 patients with symptomatic PICC-related venous thrombosis (thrombosis group) and 148 who did not have thromboses (non-thrombosis group) were selected randomly. The medical information of 159 patients (age, body mass index (BMI), diagnosis, smoking history, nutritional risk score, platelet count, leucocyte count as well as levels of D-dimer, fibrinogen, and degradation products of fibrin) were collected. Logistic regression analysis was undertaken to determine the risk factors for thrombosis. Of 2313 patients, 11 (0.47%) were found to have symptomatic PICC-related venous thrombosis by color Doppler ultrasound. Being bedridden for a long time (odds ratio [(OR]), 17.774; P=0.0017), D-dimer >5 mg/L (36.651; 0.0025) and suffering from one comorbidity (8.39; 0.0265) or more comorbidities (13.705; 0.0083) were the major risk factors for PICC-catheter related venous thrombosis by stepwise logistic regression analysis. Among 159 patients, the prevalence of PICC-associated venous thrombosis in those with ≥1 risk factor was 10.34% (12/116), in those with ≥2 risk factors was 20.41% (10/49), and in those with >3 risk factors was 26.67% (4/15). Being bedridden >72 h, having increased levels of D-dimer (>5 mg/L) and suffering from comorbidities were independent risk factors of PICC-related venous thrombosis. PMID:25664112

New developments in pediatric venous thromboembolism and anticoagulation, including the target-specific oral anticoagulants.

PubMed

Lyle, Courtney A; Sidonio, Robert F; Goldenberg, Neil A

2015-02-01

Pediatric venous thromboembolism (VTE) can affect children of all ages, requiring considerable pharmacologic intervention and is often associated with significant morbidity. Current research efforts are directed toward the development of risk-stratified VTE prevention strategies employing pharmacologic thromboprophylaxis, the optimization of conventional anticoagulation, and the investigation of the safety and efficacy of target-specific oral anticoagulants (TSOACs) in children. Recent research has considerably improved the understanding of risk factors of hospital-acquired VTE and how these factors may be employed in risk-stratified paradigms for VTE prevention in children. Additional insight has been gained in the optimization of conventional anticoagulants in special populations such as neonates and children with inflammatory conditions, and in improving the overall safety and compliance with periprocedural anticoagulation and the use of home International Normalized Ratio monitoring. Furthermore, the use of TSOACs has been described in children and is the focus of numerous ongoing clinical trials that are evaluating the safety and efficacy of these agents in children with VTE. Identification of hospital-acquired VTE risk factors may inform pediatric VTE prevention strategies. Although initial use of TSOACs may be promising, investigation of safety and efficacy in children is still underway.

Complete resolution of transplantation-associated thrombotic microangiopathy and hepatic veno-occlusive disease by defibrotide and plasma exchange.

PubMed

Beşişik, Sevgi Kalayoğlu; Oztürk, Gülistan Bahat; Calişkan, Yaşar; Sargin, Deniz

2005-03-01

Transplantation-associated thrombotic microangiopathy has been associated with significantly reduced survival following allogeneic bone marrow transplantation. We describe here the course of Transplantation-associated thrombotic microangiopathy and hepatic veno-occlusive disease, and response to plasma exchange therapy. A 19-year-old male patient underwent hematopoietic stem cell transplantation (HSCT) from his HLA-matched brother for lymphoblastic lymphoma in the first complete remission. Transplantation-associated thrombotic microangiopathy was diagnosed 17 days after transplantation. At that time, neurological abnormalities were not present. Cyclosporin A (CsA) was discontinued. Hematological stabilization was recorded. On day +20, abdominal distention, painful hepatomegaly and ascites complicated the clinical picture. With a high hepatic venous pressure gradient (18mmH20), veno-occlusive disease of the liver was diagnosed and defibrotide was started, which resulted in a dramatic cessation of pain and increase in urinary output. However, transplantation-associated thrombotic microangiopathy-related symptoms progressed and plasma exchange was instituted, which resulted in worsening of veno-occlusive disease symptoms. He was referred to the Intensive Care Unit due to respiratory compromise and was intubated. Plasma exchange was continued in order after hemofiltration. In three days, fever resolved, hemofiltration could be stopped, and ventilator dependence ended. After 19 aphereses, serum LDH level returned to normal and schistocytes were minimal on microscopic examination of the blood film. Platelet count increase was more gradual. Plasma exchange was discontinued. On the 40th day of defibrotide, all symptoms related with veno-occlusive disease were resolved and defibrotide was stopped. We think that our case is important to establish the relation and management strategy of these two small vessel complications of HSCT.

[Effect of 2 methods of occlusion adjustment on occlusal balance and muscles of mastication in patient with implant restoration].

PubMed

Wang, Rong; Xu, Xin

2015-12-01

To compare the effect of 2 methods of occlusion adjustment on occlusal balance and muscles of mastication in patients with dental implant restoration. Twenty patients, each with a single edentulous posterior dentition with no distal dentition were selected, and divided into 2 groups. Patients in group A underwent original occlusion adjustment method and patients in group B underwent occlusal plane reduction technique. Ankylos implants were implanted in the edentulous space in each patient and restored with fixed prosthodontics single unit crown. Occlusion was adjusted in each restoration accordingly. Electromyograms were conducted to determine the effect of adjustment methods on occlusion and muscles of mastication 3 months and 6 months after initial restoration and adjustment. Data was collected and measurements for balanced occlusal measuring standards were obtained, including central occlusion force (COF), asymmetry index of molar occlusal force(AMOF). Balanced muscles of mastication measuring standards were also obtained including measurements from electromyogram for the muscles of mastication and the anterior bundle of the temporalis muscle at the mandibular rest position, average electromyogram measurements of the anterior bundle of the temporalis muscle at the intercuspal position(ICP), Astot, masseter muscle asymmetry index, and anterior temporalis asymmetry index (ASTA). Statistical analysis was performed using Student 's t test with SPSS 18.0 software package. Three months after occlusion adjustment, parameters of the original occlusion adjustment method were significantly different between group A and group B in balanced occlusal measuring standards and balanced muscles of mastication measuring standards. Six months after occlusion adjustment, parameters of the original occlusion adjustment methods were significantly different between group A and group B in balanced muscles of mastication measuring standards, but was no significant difference in balanced

A Novel Nitinol Spherical Occlusion Device for Liver Cancer

PubMed Central

Hsiao, Hao-Ming; Wang, Yi-Ping; Ko, Chun-Yi; Cheng, Yu-Han; Lee, Han-Yu

2016-01-01

Liver cancer or hepatic cancer is a cancer that originates in the liver. It is formed from either the liver itself or from structures within the liver, including blood vessels or the bile duct. Liver cancer can be a life-threatening condition, but it may be cured if found early. Hepatic artery embolization is one of the treatment options involving the injection of substances to reduce the blood flow to cancer cells in the livers of patients with tumors that cannot be removed by surgery; however, this treatment has some limitations. In this paper, we propose a novel nitinol “spherical occlusion device” concept, the first of its kind in the world. Our proposed spherical occlusion device is able to reduce the blood flow to cancer cells by deploying it in the upstream hepatic artery supplying blood to the liver. Moreover, it could carry multiple chemotherapy or radioactive drugs for delivery directly to the target site. Nitinol alloy was chosen as the device material due to its excellent super-elastic property. Computational models were developed to predict the mechanical response of the device during manufacturing and deployment procedures, as well as its hemodynamic behavior. Simulation results showed that the presence of the spherical occlusion device with 14%–27% metal density deployed at the upstream location of the right hepatic artery had significant occlusion effects, with the average blood flow rate cut down by 30%–50%. A pulsed fiber laser and a series of expansions and heat treatments were developed to make the first prototype of the spherical occlusion device for the demonstration of our novel concept. PMID:28787820

Acute stroke with major intracranial vessel occlusion: Characteristics of cardioembolism and atherosclerosis-related in situ stenosis/occlusion.

PubMed

Horie, Nobutaka; Tateishi, Yohei; Morikawa, Minoru; Morofuji, Yoichi; Hayashi, Kentaro; Izumo, Tsuyoshi; Tsujino, Akira; Nagata, Izumi; Matsuo, Takayuki

2016-10-01

Acute ischemic stroke with major intracranial vessel occlusion is commonly due to cardioembolic or atherosclerosis-related in situ stenosis/occlusion, and immediate identification of these subtypes is important to establish the optimal treatment strategy. The aim of this study was to clarify the differences in clinical presentation, radiological findings, neurological temporal courses, and outcomes between these etiologies, which have not been fully evaluated. Consecutive emergency patients with acute ischemic stroke were retrospectively reviewed. Among them, patients with stroke with major intracranial vessel occlusion were analyzed with a focus on clinical and radiological findings, and a comparison was performed for those with cardioembolic or atherosclerosis-related in situ stenosis/occlusion. Of 1053 patients, 80 had stroke with acute major intracranial vessel occlusion (45 with cardioembolic and 35 with atherosclerosis-related in situ stenosis/occlusion). Interestingly, the susceptibility vessel sign (SVS) on T2-weighted MR angiography was more frequently detected in cardioembolic stroke (80.0%) than in atherosclerosis (in situ stenosis: 5.9%, chronic occlusion: 14.3%). Moreover, the proximal intra-arterial signal (IAS) on arterial spin labeling MRI and the distal IAS on fluid attenuated inversion recovery MRI was less frequently detected in chronic occlusion (27.3% and 50.0%, respectively) than in acute occlusion due to cardioembolic or in situ stenosis. Multivariate regression analysis showed that the SVS was significantly related to cardioembolism (adjusted odds ratio (OR): 21.68, P=0.004). Clinical characteristics of acute stroke with major intracranial vessel occlusion differ depending on the etiology. The SVS and proximal/distal IAS on MRI are useful to distinguish between cardioembolic and atherosclerotic-related in situ stenosis/occlusion. Copyright © 2016 Elsevier Ltd. All rights reserved.

Aqueous levels of erythropoietin in acute retinal vein occlusion with macular edema

PubMed Central

Shin, Hyun Jin; Kim, Hyung Chan; Moon, Jun Woong

2014-01-01

AIM To investigate the aqueous erythropoietin (EPO) levels and associated factors in patients with acute retinal vein occlusion (RVO). METHODS The aqueous EPO level was measured in patients with macular edema (ME) secondary to acute branched retinal vein occlusion (BRVO) or central retinal vein occlusion (CRVO). Aqueous fluid from cataract patients served as the control. We also evaluated whether aqueous level of EPO was associated with factors such as serum EPO level, non-perfusion area, central macular thickness (CMT), and arterio-venous (AV) transit time RESULTS Twenty-seven RVO patients (16 BRVO, 11 CRVO) and 9 control subjects were enrolled in the study. The aqueous EPO level (mU/mL) was higher in RVO (68.2±54.3) than that in the control subjects (12.9±5.9). More specifically, the aqueous EPO level was higher in CRVO (118.9±52.1) than that in BRVO (33.3±10.8). However, no differences were found in serum EPO levels among three groups. CMT in RVO patients had a positive correlation with the aqueous EPO level (r=0.66). Also, in terms of non-perfusion area, the aqueous EPO levels were more elevated in the ischemic subgroup than in the non-ischemic subgroup in both BRVO and CRVO. CONCLUSION Aqueous EPO levels are elevated in patients with macular edema secondary to recent onset RVO. Patients with CRVO have higher EPO levels than those with BRVO. The aqueous EPO level in RVO has a positive correlation with CMT and is associated with non-perfusion area. These results suggest that the aqueous EPO level could be associated with retinal ischemia and may be involved in the pathogenesis of macular edema secondary to RVO. PMID:24967199

Effect of Vacuum on Venous Drainage: an Experimental Evaluation on Pediatric Venous Cannulas and Tubing Systems.

PubMed

Vida, V L; Bhattarai, A; Speggiorin, S; Zanella, F; Stellin, G

2014-01-01

To observe how vacuum assisted venous drainage (VAVD) may influence the flow in a cardiopulmonary bypass circuit with different size of venous lines and cannulas. The experimental circuit was assembled to represent the cardiopulmonary bypass circuit routinely used during cardiac surgery. Wall suction was applied directly, modulated and measured into the venous reservoir. The blood flow was measured with a flow-meter positioned on the venous line. The circuit prime volume was replaced with group O date expired re-suspended red cells and Plasmalyte 148 to a hematocrit of 28% to 30%. In an open circuit with gravity siphon venous drain, angled cannulae drain more than straight ones regardless the amount of suction applied to the venous line (16 Fr straight cannula (S) drains 90 ml/min less than a 16 Fr angled (A) with a siphon gravity). The same flow can be obtained with lower cannula size and higher suction (i.e. 12 A with and -30 mmHg). Tables have been created to list how the flow varies according to the size of the cannulas, the size of the venous tubes, and the amount of suction applied to the system. Vacuum assisted venous drainage allows the use of smaller cannulae and venous lines to maintain a good venous return, which is very useful during minimally invasive approaches. The present study should be considered as a preliminary attempt to create a scientific-based starting point for a uniform the use of VAVD.

Recurrence of amblyopia after occlusion therapy.

PubMed

Bhola, Rahul; Keech, Ronald V; Kutschke, Pamela; Pfeifer, Wanda; Scott, William E

2006-11-01

To determine the stability of visual acuity (VA) after a standardized occlusion regimen in children with strabismic and/or anisometropic amblyopia. Retrospective, population-based, consecutive observational case series. Four hundred forty-nine patients younger than 10 years who underwent an occlusion trial for amblyopia and were observed until there was a recurrence of amblyopia or for a maximum of 1 year after decrease or cessation of occlusion therapy. We performed a retrospective chart review of all patients treated by occlusion therapy for strabismic and/or anisometropic amblyopia at our institution over a 34-year period. Of the 1621 patients identified in our database, 449 met the eligibility criteria and were included in this study. Patients having at least a 2 logarithm of the minimum angle of resolution (logMAR)-level improvement in VA by optotypes or a change from unmaintained to maintained fixation preference during the course of occlusion therapy were included. A recurrence of amblyopia was defined as > or =2 logMAR levels of VA reduction or reversal of fixation preference within 1 year after a decrease or cessation of occlusion therapy. Recurrence of amblyopia after a decrease or cessation of occlusion therapy and its relationship with patient age and VA of the amblyopic eye at the time of decrease or cessation of occlusion therapy. Of 653 occlusion trials, 179 (27%) resulted in recurrence of amblyopia. The recurrence was found to be inversely correlated with patient age. There was no statistically significant association between the recurrence of amblyopia and VA of the amblyopic eye at the end of maximal occlusion therapy. There is a clinically important risk of amblyopia recurrence when occlusion therapy is decreased before the age of 10 years. The risk of recurrence is inversely correlated with age (P<0.0001).

Saphenous Venous Ablation with Hot Contrast in a Canine Model

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

Prasad, Amit; Qian Zhong; Kirsch, David

2008-01-15

Purpose. To determine the feasibility, efficacy, and safety of thermal ablation of the saphenous vein with hot contrast medium. Methods. Twelve saphenous veins of 6 dogs were percutaneously ablated with hot contrast medium. In all animals, ablation was performed in the vein of one leg, followed by ablation in the contralateral side 1 month later. An occlusion balloon catheter was placed in the infragenicular segment of the saphenous vein via a jugular access to prevent unwanted thermal effects on the non-target segment of the saphenous vein. After inflation of the balloon, 10 ml of hot contrast medium was injected undermore » fluoroscopic control through a sheath placed in the saphenous vein above the ankle. A second 10 ml injection of hot contrast medium was made after 5 min in each vessel. Venographic follow-up of the ablated veins was performed at 1 month (n = 12) and 2 months (n = 6). Results. Follow-up venograms showed that all ablated venous segments were occluded at 1 month. In 6 veins which were followed up to 2 months, 4 (66%) remained occluded, 1 (16%) was partially patent, and the remaining vein (16%) was completely patent. In these latter 2 cases, an inadequate amount of hot contrast was delivered to the lumen due to a closed balloon catheter downstream which did not allow contrast to displace blood within the vessel. Discussion. Hot contrast medium thermal ablation of the saphenous vein appears feasible, safe, and effective in the canine model, provided an adequate amount of embolization agent is used.« less

Epidemiology and clinical features of inflammatory retinal vascular occlusions: pooled data from two tertiary-referral institutions.

PubMed

Agarwal, Aniruddha; Karkhur, Samendra; Aggarwal, Kanika; Invernizzi, Alessandro; Singh, Ramandeep; Dogra, Mangat R; Gupta, Vishali; Gupta, Amod; Do, Diana V; Nguyen, Quan D

2018-01-01

In a subset of patients with retinal vasculitis, there is occlusion of blood flow through the retinal vessels. These eyes are at high risk of sight-threatening complications. To characterize epidemiology, clinical course, treatment and outcomes of occlusive retinal vasculitis (ORV). Retrospective study PARTICIPANTS: Seventy-seven uveitis patients with ORV at two large tertiary-care institutions (the USA and India). Out of 2438 patients screened, 346 patients were diagnosed with retinal vasculitis of which 77 patients (96 eyes) were diagnosed with ORV. Patients with ORV (capillary, arteriolar and/or venular) were further analysed. Diagnostic criteria for occlusive vasculitis included (i) absence of blood flow in vessels (arterioles, venules and/or capillaries), (ii) capillary non-perfusion areas and/or arteriolar-venous anastomosis and (iii) intraretinal haemorrhages, cotton-wool spots or vitreous haemorrhage. Best-corrected visual acuity, treatment and complications. The mean age was 32.09 ± 13.51 years. Most common aetiologies were tuberculosis and Adamantiades-Behçet's disease in India and systemic lupus erythematosus in the USA. Best-corrected visual acuity improved from 0.38 ± 0.30 logMAR (20/48 Snellen equivalent) (baseline) to 0.25 ± 0.30 (20/35 Snellen equivalent) at final visit (P < 0.0001). Vitreous haemorrhage was seen in 31.08% eyes. Pars plana vitrectomy was performed in 12.16% eyes. Therapy with systemic steroids was required in 78.48% patients. In addition, 46.75% patients required immunomodulators and/or biologics. Occlusive retinal vasculitis is caused by heterogeneous group of uveitides depending upon the geographic location. It is imperative to identify eyes with ORV as they are predisposed to complications requiring aggressive therapy. © 2017 Royal Australian and New Zealand College of Ophthalmologists.

Left ventricular lead placement in the latest activated region guided by coronary venous electroanatomic mapping.

PubMed

Rad, Masih Mafi; Blaauw, Yuri; Dinh, Trang; Pison, Laurent; Crijns, Harry J; Prinzen, Frits W; Vernooy, Kevin

2015-01-01

Left ventricular (LV) lead placement in the latest activated region is an important determinant of response to cardiac resynchronization therapy (CRT). We investigated the feasibility of coronary venous electroanatomic mapping (EAM) to guide LV lead placement to the latest activated region. Twenty-five consecutive CRT candidates with left bundle-branch block underwent intra-procedural coronary venous EAM using EnSite NavX. A guidewire was used to map the coronary veins during intrinsic activation, and to test for phrenic nerve stimulation (PNS). The latest activated region, defined as the region with an electrical delay >75% of total QRS duration, was located anterolaterally in 18 (basal, n = 10; mid, n = 8) and inferolaterally in 6 (basal, n = 3; mid, n = 3). In one patient, identification of the latest activated region was impeded by limited coronary venous anatomy. In patients with >1 target vein (n = 12), the anatomically targeted inferolateral vein was rarely the vein with maximal electrical delay (n = 3). A concordant LV lead position was achieved in 18 of 25 patients. In six patients, this was hampered by PNS (n = 4), lead instability (n = 1), and coronary vein stenosis (n = 1). Coronary venous EAM can be used intraprocedurally to guide LV lead placement to the latest activated region free of PNS. This approach especially contributes to optimization of LV lead electrical delay in patients with multiple target veins. Conventional anatomical LV lead placement strategy does not target the vein with maximal electrical delay in many of these patients. Published on behalf of the European Society of Cardiology. All rights reserved. © The Author 2014. For permissions please email: journals.permissions@oup.com.

Prospective evaluation of chronic venous insufficiency based on foot venous pressure measurements and air plethysmography findings.

PubMed

Fukuoka, Masato; Sugimoto, Takaki; Okita, Yutaka

2003-10-01

The purpose of this study was to evaluate lower extremity venous function in patients with chronic venous insufficiency, with foot venous pressure (FVP) measurements and air plethysmography (APG). Eighty-five limbs of 63 patients with a history of chronic venous insufficiency (CVI) from 1995 to 1999 were studied. FVP parameters studied included ambulatory venous pressure (AVP), percent decrease in FVP with manual calf compression (%drop), ratio of increase in FVP over 4 seconds after release of compression (4SR%), and time to 90% recovery of FVP were measured. APG parameters studied included functional venous volume, 90% refilling time (VFT90), venous filling index, ejection fraction, and residual volume fraction. Venous filling index and 90% refilling time were significantly decreased in limbs with stasis syndrome compared with the control group. AVP, %drop, and 4SR% also showed significantly decrease in limbs with stasis syndrome compared with those without it. AVP, %drop, and 4SR% were significantly different for the primary group compared with the secondary group, whereas no differences were found with regard to any APG parameter. APG enables prediction of the presence of CVI, whereas FVP measurements are more useful for evaluation of clinical severity of CVI.

[Temporomandibular joint, occlusion and bruxism].

PubMed

Orthlieb, J D; Ré, J P; Jeany, M; Giraudeau, A

2016-09-01

Temporomandibular joint and dental occlusion are joined for better and worse. TMJ has its own weaknesses, sometimes indicated by bad functional habits and occlusal disorders. Occlusal analysis needs to be addressed simply and clearly. The term "malocclusion" is not reliable to build epidemiological studies, etiologic mechanisms or therapeutic advice on this "diagnosis". Understanding the impact of pathogenic malocclusion is not just about occlusal relationships that are more or less defective, it requires to locate them within the skeletal framework, the articular and behavioural context of the patient, and above all to assess their impact on the functions of the masticatory system. The TMJ-occlusion couple is often symbiotic, developing together in relation to its environment, compensating for its own shortcomings. However, a third partner may alter this relationship, such as bruxism, or more generally oral parafunctions, trauma or an interventionist practitioner. Copyright © 2016 Elsevier Masson SAS. All rights reserved.

Warfarin-induced Venous Limb Gangrene

PubMed Central

Grim Hostetler, Sarah; Sopkovich, Jennifer; Dean, Steven

2012-01-01

Warfarin is a commonly used anticoagulant that has been associated with several significant cutaneous side effects, most notably warfarin-induced skin necrosis. A lesser known adverse reaction to warfarin is warfarin-induced venous limb gangrene. Both cutaneous adverse effects share the same pathophysiology, but are clinically quite different. The majority of cases of warfarin-induced venous limb gangrene has been in patients with cancer or heparin-induced thrombocytopenia. However, other hypercoagulable disease states, such as the antiphospholipid antibody syndrome, can be associated with venous limb gangrene. In order to increase recognition of this important condition, the authors report a case of warfarin-induced venous limb gangrene in a patient with presumed antiphospholipid antibody syndrome and review the literature on warfarin-induced venous limb gangrene. PMID:23198012

[Recanalization of lower-limb deep veins as an index of efficacy of treatment for acute venous thrombosis].

PubMed

Kuznetsov, M R; Sapelkin, S V; Boldin, B V; Leont'ev, S G; Neskhodimov, L A

The authors analysed the results of examination and treatment of a total of 102 patients presenting with iliofemoral venous thrombosis. During treatment, ultrasonographic duplex scanning was used to determine the localization of the proximal margin of thrombotic masses, the time of appearing of the first signs of recanalization, its degree at various levels of the deep venous system, as well as alteration in velocity of the venous blood flow in the deep veins of the lower limbs. The dynamics of clinical symptoms was assessed by the visual analogue scale. Clinical and instrumental examination was performed on day 10, and then 1, 3, 6 and 12 months after the beginning of treatment. The patients were subdivided into three groups. Group One comprised 38 patients receiving therapy with low-molecular-weight heparin (enoxaprin) followed by switching to indirect anticoagulants (warfarin) combined with venotonics (original highly-purified diosmin 600 mg once daily). Group Two was composed of 33 patients receiving rivaroxaban at a dose of 15 mg twice daily for 3 weeks, followed by 20 mg once daily. Group Tree patients (n=31) were also given rivaroxaban according to the above-described standard regimen but in combination with venotonics (original highly-purified diosmin 600 mg once daily). The obtained findings showed that prescribing rivaroxaban to patients from the first day of the disease made it possible to considerably improve and accelerate the processes of restoration of patency of deep veins of lower extremities as compared with the patients taking vitamin K antagonists (warfarin). In patients receiving rivaroxaban, there were no cases of residual thrombotic occlusions of the major veins, and recanalization in three fourths of patients was assessed as good and in the remaining third as moderate. In the warfarin group, occlusion in the iliac veins was noted to persist persisted in 13% of patients, with good recanalization observed only in half of the patients. Addition

Systemic venous drainage: can we help Newton?

PubMed

Corno, Antonio F

2007-06-01

In recent years substantial progress occurred in the techniques of cardiopulmonary bypass, but the factor potentially limiting the flexibility of cardiopulmonary bypass remains the drainage of the systemic venous return. In the daily clinical practice of cardiac surgery, the amount of systemic venous return on cardiopulmonary bypass is directly correlated with the amount of the pump flow. As a consequence, the pump flow is limited by the amount of venous return that the pump is receiving. On cardiopulmonary bypass the amount of venous drainage depends upon the central venous pressure, the height differential between patient and inlet of the venous line into the venous reservoir, and the resistance in the venous cannula(s) and circuit. The factors determining the venous return to be taken into consideration in cardiac surgery are the following: (a) characteristics of the individual patient; (b) type of planned surgical procedure; (c) type of venous cannula(s); (d) type of circuit for cardiopulmonary bypass; (e) strategy of cardiopulmonary bypass; (f) use of accessory mechanical systems to increased the systemic venous return. The careful pre-operative evaluation of all the elements affecting the systemic venous drainage, including the characteristics of the individual patient and the type of required surgical procedure, the choice of the best strategy of cardiopulmonary bypass, and the use of the most advanced materials and tools, can provide a systemic venous drainage substantially better than what it would be allowed by the simple "Law of universal gravitation" by Isaac Newton.

A Review: Proteomics in Retinal Artery Occlusion, Retinal Vein Occlusion, Diabetic Retinopathy and Acquired Macular Disorders

PubMed Central

Cehofski, Lasse Jørgensen; Honoré, Bent; Vorum, Henrik

2017-01-01

Retinal artery occlusion (RAO), retinal vein occlusion (RVO), diabetic retinopathy (DR) and age-related macular degeneration (AMD) are frequent ocular diseases with potentially sight-threatening outcomes. In the present review we discuss major findings of proteomic studies of RAO, RVO, DR and AMD, including an overview of ocular proteome changes associated with anti-vascular endothelial growth factor (VEGF) treatments. Despite the severe outcomes of RAO, the proteome of the disease remains largely unstudied. There is also limited knowledge about the proteome of RVO, but proteomic studies suggest that RVO is associated with remodeling of the extracellular matrix and adhesion processes. Proteomic studies of DR have resulted in the identification of potential therapeutic targets such as carbonic anhydrase-I. Proliferative diabetic retinopathy is the most intensively studied stage of DR. Proteomic studies have established VEGF, pigment epithelium-derived factor (PEDF) and complement components as key factors associated with AMD. The aim of this review is to highlight the major milestones in proteomics in RAO, RVO, DR and AMD. Through large-scale protein analyses, proteomics is bringing new important insights into these complex pathological conditions. PMID:28452939

Pathophysiological Mechanisms of Chronic Venous Disease and Implications for Venoactive Drug Therapy.

PubMed

Mansilha, Armando; Sousa, Joel

2018-06-05

Chronic venous disease (CVD) is a common pathology, with significant physical and psychological impacts for patients and high economic costs for national healthcare systems. Throughout the last decades, several risk factors for this condition have been identified, but only recently, have the roles of inflammation and endothelial dysfunction been properly assessed. Although still incompletely understood, current knowledge of the pathophysiological mechanisms of CVD reveals several potential targets and strategies for therapeutic intervention, some of which are addressable by currently available venoactive drugs. The roles of these drugs in the clinical improvement of venous tone and contractility, reduction of edema and inflammation, as well as in improved microcirculation and venous ulcer healing have been studied extensively, with favorable results reported in the literature. Here, we aim to review these pathophysiological mechanisms and their implications regarding currently available venoactive drug therapies.

Central venous catheters: incidence and predictive factors of venous thrombosis.

PubMed

Hammes, Mary; Desai, Amishi; Pasupneti, Shravani; Kress, John; Funaki, Brian; Watson, Sydeaka; Herlitz, Jean; Hines, Jane

2015-07-01

Central venous catheter access in an acute setting can be a challenge given underlying disease and risk for venous thrombosis. Peripherally inserted central venous catheters (PICCs) are commonly placed but limit sites for fistula creation in patients with chronic renal failure (CKD). The aim of this study is to determine the incidence of venous thrombosis from small bore internal jugular (SBIJ) and PICC line placement. This investigation identifies populations of patients who may not be ideal candidates for a PICC and highlights the importance of peripheral vein preservation in patients with renal failure. A venous Doppler ultrasound was performed at the time of SBIJ insertion and removal to evaluate for thrombosis in the internal jugular vein. Data was collected pre- and post-intervention to ascertain if increased vein preservation knowledge amongst the healthcare team led to less use of PICCs. Demographic factors were collected in the SBIJ and PICC groups and risk factor analysis was completed. 1,122 subjects had PICC placement and 23 had SBIJ placement. The incidence of thrombosis in the PICC group was 10%. One patient with an SBIJ had evidence of central vein thrombosis when the catheter was removed. Univariate and multivariate analysis demonstrated a history of transplant, and the indication of total parenteral nutrition was associated with thrombosis (p<0.001). The decrease in PICCs placed in patients with CKD 6 months before and after intervention was significant (p<0.05). There are subsets of patients ith high risk for thrombosis who may not be ideal candidates for a PICC.

Lung vaso-occlusion in sickle cell disease mediated by arteriolar neutrophil-platelet microemboli.

PubMed

Bennewitz, Margaret F; Jimenez, Maritza A; Vats, Ravi; Tutuncuoglu, Egemen; Jonassaint, Jude; Kato, Gregory J; Gladwin, Mark T; Sundd, Prithu

2017-01-12

In patients with sickle cell disease (SCD), the polymerization of intraerythrocytic hemoglobin S promotes downstream vaso-occlusive events in the microvasculature. While vaso-occlusion is known to occur in the lung, often in the context of systemic vaso-occlusive crisis and the acute chest syndrome, the pathophysiological mechanisms that incite lung injury are unknown. We used intravital microscopy of the lung in transgenic humanized SCD mice to monitor acute vaso-occlusive events following an acute dose of systemic lipopolysaccharide sufficient to trigger events in SCD but not control mice. We observed cellular microembolism of precapillary pulmonary arteriolar bottlenecks by neutrophil-platelet aggregates. Blood from SCD patients was next studied under flow in an in vitro microfluidic system. Similar to the pulmonary circulation, circulating platelets nucleated around arrested neutrophils, translating to a greater number and duration of neutrophil-platelet interactions compared with normal human blood. Inhibition of platelet P-selectin with function-blocking antibody attenuated the neutrophil-platelet interactions in SCD patient blood in vitro and resolved pulmonary arteriole microembolism in SCD mice in vivo. These results establish the relevance of neutrophil-platelet aggregate formation in lung arterioles in promoting lung vaso-occlusion in SCD and highlight the therapeutic potential of targeting platelet adhesion molecules to prevent acute chest syndrome.

External jugular venous pressure as an alternative to conventional central venous pressure in right lobe donor hepatectomies.

PubMed

Abdullah, Mohamed Hussein; Soliman, Hossam El Deen; Morad, Wessam Saber

2011-12-01

Many centers have adopted central vein cannulation both for central venous pressure monitoring and fluid administration for right hepatectomy in living-liver donors. However, use of central venous catheters is associated with adverse events that are hazardous to patients and expensive to treat. This study sought to examine the use of external jugular venous pressure as an alternative to conventional central venous pressure in right lobe donor hepatectomies Forty ASA grade I adult living liver-donors without a known history of significant cardiac or pulmonary diseases were enrolled in this prospective observational study. Paired measurement of venous pressures (external jugular venous pressure and internal jugular venous pressure) were taken at the following times: after induction of anesthesia, 30 minutes after skin incision, during right lobe mobilization (every 15 minutes), during hepatic transaction (every 15 minutes), after right lobe resection (every 15 minutes), and after abdominal closure. Paired measurements were equal in 47.5%, 53.5%, 61.5%, 46.3%, and 52.5% for after induction, after skin incision, right lobe mobilization, right lobe transection, after resection, and before abdominal closure periods. However, all measurements were within acceptable limits of bias measurements (± 2 mm Hg). Central venous pressure catheter placement can be avoided and replaced by a less-invasive method such as external jugular venous pressure (which gave an acceptable estimate of central venous pressure in all phases of right lobe resection) in living-donor liver transplant and allowed equivalent monitor even during fluid restriction phases.

Comparison of Oseltamivir and Oseltamivir Carboxylate Concentrations in Venous Plasma, Venous Blood, and Capillary Blood in Healthy Volunteers

PubMed Central

Instiaty, Insti; Lindegardh, Niklas; Jittmala, Podjanee; Hanpithakpong, Warunee; Blessborn, Daniel; Pukrittayakamee, Sasithon; White, Nicholas J.

2013-01-01

Oseltamivir and oseltamivir carboxylate concentrations were measured in venous plasma, venous blood, and capillary blood taken simultaneously from 24 healthy volunteers. Median (range) venous-blood-to-plasma ratios were 1.42 (0.920 to 1.97) for oseltamivir and 0.673 (0.564 to 0.814) for oseltamivir carboxylate. Capillary blood/venous plasma ratios were 1.32 (0.737 to 3.16) for oseltamivir and 0.685 (0.502 to 1.34) for oseltamivir carboxylate. Oseltamivir concentrations in venous and capillary blood were similar. Oseltamivir carboxylate showed a time-dependent distribution between venous and capillary blood. PMID:23507284

Home Treatment of Deep Venous Thrombosis According to Comorbid Conditions.

PubMed

Stein, Paul D; Matta, Fadi; Hughes, Mary J

2016-04-01

Cautious exploration of the safety of home treatment of deep venous thrombosis has been recommended by many. Our goal was to identify categories of patients with deep venous thrombosis who typically are hospitalized, and categories frequently treated at home. The Nationwide Emergency Department Sample and the Nationwide Inpatient Sample, 2007-2012, were used to determine the number of patients seen in emergency departments throughout the US with deep venous thrombosis and no diagnosis of pulmonary embolism, the proportion of such patients hospitalized according to comorbid conditions and age, the proportion discharged early (≤2 days), and charges for hospitalization and emergency department visits. From 2007-2012, home treatment was selected for 905,152 of 2,671,452 (33.9%) patients with deep venous thrombosis. Home treatment was more frequent in those with no comorbid conditions than with comorbid conditions, 58.0% compared with 15.5% (P <.0001). Early discharge (≤2 days) was in 23.9% with no comorbid conditions, compared with 12.8% with comorbid conditions. Among patients aged 18-50 years, home treatment was selected in 62.9% with no comorbid conditions, compared with 24.2% with comorbid conditions (P <.0001). Among hospitalized patients with no comorbid conditions, 40.7% were aged 18-50 years. Their charges for hospitalization in 2012 were $494 million. Patients aged 50 years or younger with deep venous thrombosis and no comorbid conditions appear to be a group that can be targeted for more frequent home treatment, which would save millions of dollars. Copyright © 2016 Elsevier Inc. All rights reserved.

To what extent might deep venous thrombosis and chronic venous insufficiency share a common etiology?

PubMed

Malone, P Colm; Agutter, P S

2009-08-01

According to the valve cusp hypoxia hypothesis (VCHH), deep venous thrombosis is caused by sustained non-pulsatile (streamline) venous blood flow. This leads to hypoxemia in the valve pockets; hypoxic injury to the inner (parietalis) endothelium of the cusp leaflets activates the elk-1/egr-1 pathway, leading to leukocyte and platelet swarming at the site of injury and, potentially, blood coagulation. Here, we propose an extension of the VCHH to account for chronic venous insufficiency. First, should the foregoing events not proceed to frank thrombogenesis, the valves may nevertheless be chronically injured and become incompetent. Serial incompetence in lower limb valves may then generate ''passive'' venous hypertension. Second, should ostial valve thrombosis obstruct venous return from muscles via tributaries draining into the femoral vein, as Virchow illustrated, ''active'' venous hypertension may supervene: muscle contraction would force the blood in the vessels behind the blocked ostial valves to re-route. Passive or active venous hypertension opposes return flow, leading to luminal hypoxemia and vein wall distension, which in turn may impair vasa venarum perfusion; the resulting mural endothelial hypoxia would lead to leukocyte invasion of the wall and remodelling of the media. We propose that varicose veins result if gross active hypertension stretches the valve ''rings'', rendering attached valves incompetent caudad to obstructed sites, replacing normal centripetal flow in perforating veins with centrifugal flow and over-distending those vessels. We also discuss how hypoxemia-related venous/capillary wall lesions may lead to accumulation of leukocytes, progressive blockage of capillary blood flow, lipodermosclerosis and skin ulceration.

Necessity of heparin for maintaining peripheral venous catheters: A systematic review and meta-analysis

PubMed Central

You, Tao; Jiang, Jianliang; Chen, Jianchang; Xu, Weiting; Xiang, Li; Jiao, Yang

2017-01-01

Heparin has typically been used as a flushing or infusion solution for vascular lines in daily practice. However, several clinical trials have yielded controversial results about the benefits of heparin in maintaining peripheral venous catheters. The present meta-analysis was conducted to evaluate the efficacy of heparin on the patency profiles and complications in peripheral intravenous catheters. PubMed, Embase and Cochrane Central Register of Controlled Trials were searched up to February 2016 for randomized controlled trials comparing heparin with placebo in maintaining peripheral intravenous catheters. Additional studies were retrieved from the reference lists of identified articles. In total 32 eligible studies were included, from which the pooled standard mean difference (SMD), relative risk (RR) and corresponding 95% confidence interval (CI) were calculated. The use of heparin as a continuous infusion significantly prolonged the duration of patency (SMD, 0.90; 95% CI, 0.48–1.32; P<0.001), reduced rates of infusion failure (RR, 0.83; 95% CI, 0.76–0.92; P<0.001) and occlusion (RR, 0.82; 95% CI, 0.69–0.98; P<0.05) in a peripheral intravenous catheter. However, there were no significant changes in the duration of patency and infusion failure when heparin was used intermittently as a flushing solution, although a significantly decreased risk of occlusion was observed in this setting (RR, 0.80; 95% CI, 0.66–0.98; P<0.05). Furthermore, the risk of phlebitis was significantly decreased by both continuous infusion (RR, 0.66; 95% CI, 0.58–0.75; P<0.01) and intermittent flushing (RR, 0.70; 95% CI, 0.56–0.86; P<0.01) of heparin in peripheral venous catheters. In conclusion, the use of heparin as continuous infusion in peripheral intravenous catheters improved the duration of patency, reduced infusion failure and phlebitis, whereas heparin as intermittent flushing showed more benefits in ameliorating phlebitis rather than in patency profiles. PMID:28810636

Pathophysiology of Venous Thromboembolism with Respect to the Anatomical Features of the Deep Veins of Lower Limbs: A Review.

PubMed

Ro, Ayako; Kageyama, Norimasa; Mukai, Toshiji

2017-06-25

Here the pathophysiology of venous thromboembolism is reviewed with respect to the anatomical features of the deep veins of lower limbs. A thrombus is less likely to form in the thigh veins compared with that in the calf veins; however, clinical symptoms are more likely to appear in the thigh veins owing to vascular occlusion. When a patient is bedridden, thrombosis is more likely to occur in the intramuscular vein, which mainly depends on muscular pumping and the venous valve, rather than in the three crural branches, which mainly depends on the pulsation of the accompanying artery. Thrombi are prone to be generated in the soleal vein compared with those in the gastrocnemius vein because of the vein and muscle structures. A soleal vein thrombosis grows toward the proximal veins along the drainage veins. To prevent a sudden pulmonary thromboembolism-related death in bedridden patients, preventing soleal vein thrombus formation and observing the thrombus proximal propagation via the drainage veins are clinically important. When deep vein thrombosis occurs, avoiding embolization and sequela caused by the thrombus organization is necessary.

Pathophysiology of Venous Thromboembolism with Respect to the Anatomical Features of the Deep Veins of Lower Limbs: A Review

PubMed Central

Ro, Ayako; Kageyama, Norimasa; Mukai, Toshiji

2017-01-01

Here the pathophysiology of venous thromboembolism is reviewed with respect to the anatomical features of the deep veins of lower limbs. A thrombus is less likely to form in the thigh veins compared with that in the calf veins; however, clinical symptoms are more likely to appear in the thigh veins owing to vascular occlusion. When a patient is bedridden, thrombosis is more likely to occur in the intramuscular vein, which mainly depends on muscular pumping and the venous valve, rather than in the three crural branches, which mainly depends on the pulsation of the accompanying artery. Thrombi are prone to be generated in the soleal vein compared with those in the gastrocnemius vein because of the vein and muscle structures. A soleal vein thrombosis grows toward the proximal veins along the drainage veins. To prevent a sudden pulmonary thromboembolism-related death in bedridden patients, preventing soleal vein thrombus formation and observing the thrombus proximal propagation via the drainage veins are clinically important. When deep vein thrombosis occurs, avoiding embolization and sequela caused by the thrombus organization is necessary. PMID:29034034

Plasma Glucose Level Is Predictive of Serum Ammonia Level After Retrograde Occlusion of Portosystemic Shunts.

PubMed

Ishikawa, Tsuyoshi; Aibe, Yuki; Matsuda, Takashi; Iwamoto, Takuya; Takami, Taro; Sakaida, Isao

2017-09-01

The purpose of this study was to evaluate predictors of reduction in ammonia levels by occlusion of portosystemic shunts (PSS) in patients with cirrhosis. Forty-eight patients with cirrhosis (21 women, 27 men; mean age, 67.8 years) with PSS underwent balloon-occluded retrograde transvenous obliteration (BRTO) at one institution between February 2008 and June 2014. The causes of cirrhosis were hepatitis B in one case, hepatitis C in 20 cases, alcohol in 15 cases, nonalcoholic steatohepatitis in eight cases, and other conditions in four cases. The Child-Pugh classes were A in 24 cases, B in 23 cases, and C in one case. The indication for BRTO was gastric varices in 40 cases and hepatic encephalopathy in eight cases. Testing was conducted before and 1 month after the procedure. Statistical analyses were performed to identify predictors of a clinically significant decline in ammonia levels after BRTO. Occlusion of PSS resulted in a clinically significant decrease in ammonia levels accompanied by increased portal venous flow and improved Child-Pugh score. Univariate analyses showed that a reduction in ammonia levels due to BRTO was significantly related to lower plasma glucose levels, higher RBC counts, and higher hemoglobin concentration before the treatment. Furthermore, multivariate logistic regression identified preoperative plasma glucose level as the strongest independent predictor of a significant ammonia reduction in response to BRTO. In addition, although BRTO resulted in significantly declined ammonia levels in patients with normal glucose tolerance before the procedure, ammonia levels were not significantly decreased after shunt occlusion in patients with diabetes mellitus or impaired glucose tolerance before BRTO, according to 75-g oral glucose tolerance test results. Preoperative plasma glucose level is a useful predictor of clinically significant ammonia reduction resulting from occlusion of PSS in patients with cirrhosis. Even if PSS are present, control

In vivo ultrasound visualization of non-occlusive blood clots with thrombin-sensitive contrast agents.

PubMed

Nakatsuka, Matthew A; Barback, Christopher V; Fitch, Kirsten R; Farwell, Alexander R; Esener, Sadik C; Mattrey, Robert F; Cha, Jennifer N; Goodwin, Andrew P

2013-12-01

The use of microbubbles as ultrasound contrast agents is one of the primary methods to diagnose deep venous thrombosis. However, current microbubble imaging strategies require either a clot sufficiently large to produce a circulation filling defect or a clot with sufficient vascularization to allow for targeted accumulation of contrast agents. Previously, we reported the design of a microbubble formulation that modulated its ability to generate ultrasound contrast from interaction with thrombin through incorporation of aptamer-containing DNA crosslinks in the encapsulating shell, enabling the measurement of a local chemical environment by changes in acoustic activity. However, this contrast agent lacked sufficient stability and lifetime in blood to be used as a diagnostic tool. Here we describe a PEG-stabilized, thrombin-activated microbubble (PSTA-MB) with sufficient stability to be used in vivo in circulation with no change in biomarker sensitivity. In the presence of actively clotting blood, PSTA-MBs showed a 5-fold increase in acoustic activity. Specificity for the presence of thrombin and stability under constant shear flow were demonstrated in a home-built in vitro model. Finally, PSTA-MBs were able to detect the presence of an active clot within the vena cava of a rabbit sufficiently small as to not be visible by current non-specific contrast agents. By activating in non-occlusive environments, these contrast agents will be able to detect clots not diagnosable by current contrast agents. Copyright © 2013 Elsevier Ltd. All rights reserved.

Risk factors for central venous catheter thrombotic complications in children and adolescents with cancer.

PubMed

Revel-Vilk, S; Yacobovich, J; Tamary, H; Goldstein, G; Nemet, S; Weintraub, M; Paltiel, O; Kenet, G

2010-09-01

The use of central venous catheters (CVCs) has greatly improved the quality of care in children with cancer, yet these catheters may cause serious infectious and thrombotic complications. The aim of this prospective registry study was to assess the host and CVC-related risk factors for CVC-created thrombotic complications. Patients undergoing CVC insertion for chemotherapy were followed prospectively for CVC complications. At the time of enrollment, demographic, clinical, and CVC-related data, and family history of thrombosis were collected. Survival and Cox regression analyses were performed. A total of 423 CVCs were inserted into 262 patients for a total of 76,540 catheter days. The incidence of CVC-related deep-vein thrombosis (DVT) was 0.13 per 1000 catheter-days (95% confidence interval [CI], 0.06-0.24). Insertion of peripherally inserted central catheters (PICCs) and insertion in an angiography suite significantly increased the risk of symptomatic CVC-related DVT. The incidence of CVC occlusion was 1.35 per 1000 catheter-days (95% CI, 1.1-1.63). Positive family history of thrombosis significantly increased the risk of CVC occlusion (hazard ratio [HR], 2.16; 95% CI, 1.2-3.8). The CVC-related risk factors were insertion of Hickman catheters, insertion in angiography suite, and proximal-tip location. Patients developing at least 1 episode of both CVC occlusion and infection had an increased risk for developing symptomatic CVC-related DVT (HR, 4.15; 95% CI, 1.2-14.4). Both patient-related and CVC-related factors are associated with higher risk of symptomatic thrombotic complications. These risk factors could be used in the clinical setting and in developing future studies for CVC thromboprophylaxis.

Targeted True Lumen Re-Entry With the Outback Catheter: Accuracy, Success, and Complications in 100 Peripheral Chronic Total Occlusions and Systematic Review of the Literature.

PubMed

Kitrou, Panagiotis; Parthipun, Aneeta; Diamantopoulos, Athanasios; Paraskevopoulos, Ioannis; Karunanithy, Narayan; Katsanos, Konstantinos

2015-08-01

To report a single-center experience with the Outback re-entry device for targeted distal true lumen re-entry during subintimal recanalization of chronic total occlusions (CTOs) and compare the results with a systematic review of the literature. Between February 2011 and July 2013, 104 Outback devices were employed in 91 patients (mean age 64±9 years; 57 men) for subintimal recanalization of 100 vessels with CTOs after initial failure of spontaneous reentry. Fifty-two cases involved a retrograde approach to aortoiliac occlusions and 48 were re-entry attempts in infrainguinal CTOs. Outcome measures included complications and technical success, defined as successful targeted re-entry at the preplanned site of the distal true lumen. To evaluate device accuracy, the re-entry distance (between the point of true vessel reconstitution and the eventual re-entry point) was measured. Outback success was 93% (93/100); only 7 cases failed owing to heavy calcification (5/52 aortoiliac vs 2/48 infrainguinal, p=0.44). Re-entry was highly accurate, with a re-entry distance of ~1 cm in both subgroups (1.2±0.1 cm in aortoiliac vs 1.3±0.1 cm in infrainguinal, p=0.40). There were no major and 17 minor complications (9/52 aortoiliac vs 8/48 infrainguinal, p=0.93). Results are in line with the systematic review that identified 11 studies (only 1 randomized trial) involving mostly the femoropopliteal segment (119 aortoiliac and 464 infrainguinal segments). The pooled Outback success rate was 90% (95% confidence interval 85% to 94%) and the pooled complication rate was 4.3% (95% confidence interval 1.6% to 8.3%). The Outback device is safe and has a very high rate of achieving targeted true lumen re-entry, which minimizes the sacrifice of healthy vessel in the aortoiliac and infrainguinal arteries. © The Author(s) 2015.

Chronic total occlusion due to diffuse in-stent restenosis: is brachytherapy the solution?

PubMed

Nikolsky, E; Gruberg, L; Rosenblatt, E; Grenadier, E; Boulos, M; Bernstein, Z; Huber, A; Gitman, R; Bar-Deroma, R; Markiewicz, W; Beyar, R

2004-01-01

Percutaneous coronary intervention of chronic total occlusions (CTO) is associated with a significantly higher incidence of reocclusion and restenosis compared with non-total occlusions. Randomized and observational trials have demonstrated the effectiveness of intracoronary brachytherapy (ICBT) for the prevention of recurrent in-stent restenosis. However, limited data are available on the effectiveness of ICBT in patients with totally occluded in-stent restenosis. The authors assessed the long-term outcome of patients treated with intracoronary gamma radiation for totally occluded in-stent restenotic lesions. Percutaneous coronary intervention and subsequent catheter-based irradiation with iridium-192 was performed in 100 patients (103 vessels) with diffuse in-stent restenosis. At baseline, CTO of the target vessel at the site of the stent was present in 15 vessels (14.5%). Follow-up data were collected during follow-up visits and from telephone interviews. Repeat coronary angiography was performed in symptomatic patients with clinical restenosis. Clinical and angiographic characteristics were similar between the two groups, although there was a trend towards more unstable angina at the index procedure in CTO patients (66.7% versus 41.4%; p = 0.12) compared with patients without non-total occlusions. A higher percentage of patients (53.3%) with CTO required longer radiation sources (14 seeds, covering a length of 55 mm), compared with 23.9% of patients with non-total occlusion (p = 0.04). With a mean follow-up period of 47.5 +/- 24.0 months, major adverse cardiac events (MACE) were observed in 10 of 15 patients (66.7%) with CTO compared with 25 out of 88 patients (28.4%) without CTO (p = 0.009). According to multivariate analysis, total occlusion of the target vessel at baseline was the single independent predictor of MACE at one-year follow-up (relative risk 16.2, 95% confidence interval 4.2-62.9; p < 0.0001). This study shows that the use of gamma radiation for

Cerebral venous circulatory system evaluation by ultrasonography.

PubMed

Zavoreo, Iris; Basić-Kes, Vanja; Zadro-Matovina, Lucija; Lisak, Marijana; Corić, Lejla; Cvjeticanin, Timon; Ciliga, Dubravka; Bobić, Tatjana Trost

2013-06-01

Venous system can be classified as pulmonary veins, systemic veins and venous sinuses that are present only within the skull. Cerebral venous system is divided into two main parts, the superficial and the deep system. The main assignment of veins is to carry away deoxygenated blood and other maleficient materials from the tissues towards the heart. Veins have thinner walls and larger lumina than arteries. Between 60% and 70% of the total blood volume is found in veins. The major factors that influence venous function are the respiratory cycle, venous tone, the function of the right heart, gravity, and the muscle pump. Venous system, in general, can be presented by selective venography, Doppler sonography, computed tomography (CT) venography and magnetic resonance (MR) venography, and cerebral venous system can be displayed by selective venography, cerebral CT venography, cerebral MR venography, and specialized extracranial and transcranial Doppler sonography. The aim of this paper is to show the possibilities of intracranial and extracranial ultrasound evaluation of the head and neck venous circulation and chronic cerebrospinal venous insufficiency as one of the most common pathologies evaluated as part of neurodegenerative processes in the central nervous system.

The Kallikrein Inhibitor from Bauhinia bauhinioides (BbKI) shows antithrombotic properties in venous and arterial thrombosis models.

PubMed

Brito, Marlon V; de Oliveira, Cleide; Salu, Bruno R; Andrade, Sonia A; Malloy, Paula M D; Sato, Ana C; Vicente, Cristina P; Sampaio, Misako U; Maffei, Francisco H A; Oliva, Maria Luiza V

2014-05-01

The Bauhinia bauhinioides Kallikrein Inhibitor (BbKI) is a Kunitz-type serine peptidase inhibitor of plant origin that has been shown to impair the viability of some tumor cells and to feature a potent inhibitory activity against human and rat plasma kallikrein (Kiapp 2.4 nmol/L and 5.2 nmol/L, respectively). This inhibitory activity is possibly responsible for an effect on hemostasis by prolonging activated partial thromboplastin time (aPTT). Because the association between cancer and thrombosis is well established, we evaluated the possible antithrombotic activity of this protein in venous and arterial thrombosis models. Vein thrombosis was studied in the vena cava ligature model in Wistar rats, and arterial thrombosis in the photochemical induced endothelium lesion model in the carotid artery of C57 black 6 mice. BbKI at a concentration of 2.0 mg/kg reduced the venous thrombus weight by 65% in treated rats in comparison to rats in the control group. The inhibitor prolonged the time for total artery occlusion in the carotid artery model mice indicating that this potent plasma kallikrein inhibitor prevented thrombosis. Copyright © 2014 Elsevier Ltd. All rights reserved.

Agreement of arterial sodium and arterial potassium levels with venous sodium and venous potassium in patients admitted to intensive care unit.

PubMed

Nanda, Sunil Kumar; Ray, Lopamudra; Dinakaran, Asha

2015-02-01

Electrolyte abnormalities are one of the common causes of morbidity and mortality in critically ill patients. The turnaround time for electrolyte reporting should be as low as possible. Electrolytes are measured conventionally in serum obtained from venous blood by electrolyte analyser which takes 20 to 30 min. Point of care analysers are now available where in electrolytes can be measured in arterial blood within 5 min. This study was done to study the agreement of arterial sodium and arterial potassium with venous sodium and venous potassium levels. Venous sodium and venous potassium levels and arterial sodium and arterial potassium levels were analysed on 206 patient samples admitted to Intensive Care Unit (ICU). The venous values were compared with the arterial values for correlation. Venous sodium was compared with arterial sodium by spearman correlation. Venous potassium was compared with arterial potassium by pearson correlation. The mean value of arterial sodium was 134 and venous sodium was 137. The mean value of arterial potassium was 3.6 and venous potassium was 4.1. The correlation coefficient obtained for sodium was 0.787 and correlation coefficient obtained for potassium was 0.701. There was positive correlation of arterial sodium and arterial potassium with venous sodium and venous potassium indicating agreement between the parameters. Arterial sodium and arterial potassium can be used instead of venous sodium and venous potassium levels in management of critically ill patients.

Factor XI and XII as antithrombotic targets.

PubMed

Müller, Felicitas; Gailani, David; Renné, Thomas

2011-09-01

Arterial and venous thrombosis are major causes of morbidity and mortality, and the incidence of thromboembolic diseases increases as a population ages. Thrombi are formed by activated platelets and fibrin. The latter is a product of the plasma coagulation system. Currently available anticoagulants such as heparins, vitamin K antagonists and inhibitors of thrombin or factor Xa target enzymes of the coagulation cascade that are critical for fibrin formation. However, fibrin is also necessary for terminating blood loss at sites of vascular injury. As a result, anticoagulants currently in clinical use increase the risk of bleeding, partially offsetting the benefits of reduced thrombosis. This review focuses on new targets for anticoagulation that are associated with minimal or no therapy-associated increased bleeding. Data from experimental models using mice and clinical studies of patients with hereditary deficiencies of coagulation factors XI or XII have shown that both of these clotting factors are important for thrombosis, while having minor or no apparent roles in processes that terminate blood loss (hemostasis). Hereditary deficiency of factor XII (Hageman factor) or factor XI, plasma proteases that initiate the intrinsic pathway of coagulation, impairs thrombus formation and provides protection from vascular occlusive events, while having a minimal impact on hemostasis. As the factor XII-factor XI pathway contributes to thrombus formation to a greater extent than to normal hemostasis, pharmacological inhibition of these coagulation factors may offer the exciting possibility of anticoagulation therapies with minimal or no bleeding risk.

Influence of the fast-processing technique on the number of the occlusal contacts and occlusal vertical dimension of complete dentures.

PubMed

Atashrazm, Parsa; Alavijeh, Leila Zamani; Afshar, Maryam Sadat Sadrzadeh

2011-03-01

Occlusal errors during acryl processing affect the retention and stability of complete dentures. The aim of the present study was to assess the influence of a short curing technique on the number of occlusal contacts and the occlusal vertical dimension (OVD) of complete dentures. Complete dentures were prepared. The number of occlusal contacts was recorded in centric relation (CR) using 60 µ articulation paper. The OVD was recorded with the waxed trial denture in place. Dentures were then invested and processed with compression molding and short cure water bath technique. The number of occlusal contacts was recorded again. The amount of pin opening was measured for all of the complete dentures on the articulator. Data were analyzed with paired t-test to determine the alterations. The mean number of occlusal contacts before and after processing was 10.9 ± 2.4 and 6.3 ± 3.1 respectively (4.7 ± 1.9 decrease; p < 0.001). A 2 mm mean increase in OVD was observed in 47.7% of the dentures with < 6 occlusal contact changes and 88.9% of the dentures with ≥ 6 occlusal contact changes (p < 0.003). A significant change in the number of occlusal contacts was associated with an OVD increased up to two times. The short curing technique seems to be related to the decreased occlusal contacts and increased OVD. CLINICAL SIGNIFICANCES: More time is needed to adjust the occlusal errors of this method, because it has a negative effect on the morphologic pattern of artificial teeth of complete dentures and thus should be used carefully.

Diagnostic value of color doppler ultrasonography in detecting stenosis and occlusion of central veins in patients with chronic kidney disease.

PubMed

Rad, Masoud Pezeshki; Kazemzadeh, Gholam Hosain; Ziaee, Masood; Azarkar, Ghodsieh

2015-03-01

Venography is an invasive diagnostic test that uses contrast material that provides a picture of the condition of the veins. But, complications, including adverse effects on the kidney, do occur. On the other hand, with the current technological development, application of ultrasound in the diagnosis of obstructive diseases of the veins is gaining popularity, being non-invasive, easy to perform and cost-effective. The aim of this study was to evaluate the diagnostic value of Doppler sonography in the diagnosis of central vein stenosis. In this descriptive-analytical study, 41 hemodialysis patients who had been referred for 50 upper limb venographies to the radiology department of Imam Reza (AS) were included. Patients with chronic kidney disease with a history of catheterization of the vein, jugular or subclavian, and who had established fistulas or synthetic vascular grafts were targeted. Central venous ultrasound was performed on both sides to evaluate stenosis or occlusion. Venography was performed by the radiologist the next day or the day before hemodialysis. Data on demographic characteristics, findings of clinical examination and findings of ultrasound as well as venography were recorded by using the SPSS software, Chi-square test and Spearman correlation, and Kappa agreement was calculated for sensitivity, specificity and predictive values. Twenty-three (56%) patients were male subjects and 18 patients (44%) were female. Twenty-three (56%) patients of the study population were aged <60 years and 18 (43/9%) patients were aged >60 years. The overall sensitivity, specificity and positive predictive value and negative predictive value of Doppler sonography in the proximal veins in hemodialysis patients compared with venography were, respectively, 80.9%, 79.3%, 73.9% and 85.1%. Color Doppler sonography, as a non-invasive method, could be a good alternative for venography in the assessment of the upper limb with central vein stenosis and occlusion.

Retinal venous thrombosis in a young patient with coagulation factor XII deficiency.

PubMed

Borrego-Sanz, L; Santos-Bueso, E; Sáenz-Francés, F; Martínez-de-la-Casa, J M; García-Feijoo, J; Gegúndez-Fernández, J A; García-Sánchez, J

2014-08-01

A 35-year-old woman, with no relevant medical history, was referred for sudden vision loss in the left eye. Ophthalmological examination showed best corrected visual acuity of 1.0 in the right eye and 0.3 in left eye, with normal anterior pole and intraocular pressure. Fundus examination of the left eye revealed a venous thrombosis in the superior temporal branch, with dilated and tortuous retinal veins. The patient was referred to the hematology unit for thrombophilia study, and was diagnosed with a coagulation XII or Hageman factor deficiency. The development of retinal vessel occlusions, in patients under 50 years of age, is frequently associated with thrombophilia or hypercoagulability disorders. Factor XII deficiency is a rare condition, and its presence could contribute to a higher risk of thromboembolic events. Copyright © 2013 Sociedad Española de Oftalmología. Published by Elsevier Espana. All rights reserved.

Combined oral contraceptives: venous thrombosis.

PubMed

de Bastos, Marcos; Stegeman, Bernardine H; Rosendaal, Frits R; Van Hylckama Vlieg, Astrid; Helmerhorst, Frans M; Stijnen, Theo; Dekkers, Olaf M

2014-03-03

Combined oral contraceptive (COC) use has been associated with venous thrombosis (VT) (i.e., deep venous thrombosis and pulmonary embolism). The VT risk has been evaluated for many estrogen doses and progestagen types contained in COC but no comprehensive comparison involving commonly used COC is available. To provide a comprehensive overview of the risk of venous thrombosis in women using different combined oral contraceptives. Electronic databases (Pubmed, Embase, Web of Science, Cochrane, CINAHL, Academic Search Premier and ScienceDirect) were searched in 22 April 2013 for eligible studies, without language restrictions. We selected studies including healthy women taking COC with VT as outcome. The primary outcome of interest was a fatal or non-fatal first event of venous thrombosis with the main focus on deep venous thrombosis or pulmonary embolism. Publications with at least 10 events in total were eligible. The network meta-analysis was performed using an extension of frequentist random effects models for mixed multiple treatment comparisons. Unadjusted relative risks with 95% confidence intervals were reported.Two independent reviewers extracted data from selected studies. 3110 publications were retrieved through a search strategy; 25 publications reporting on 26 studies were included. Incidence of venous thrombosis in non-users from two included cohorts was 0.19 and 0.37 per 1 000 person years, in line with previously reported incidences of 0,16 per 1 000 person years. Use of combined oral contraceptives increased the risk of venous thrombosis compared with non-use (relative risk 3.5, 95% confidence interval 2.9 to 4.3). The relative risk of venous thrombosis for combined oral contraceptives with 30-35 μg ethinylestradiol and gestodene, desogestrel, cyproterone acetate, or drospirenone were similar and about 50-80% higher than for combined oral contraceptives with levonorgestrel. A dose related effect of ethinylestradiol was observed for gestodene

Application of photogrammetry for analysis of occlusal contacts.

PubMed

Shigeta, Yuko; Hirabayashi, Rio; Ikawa, Tomoko; Kihara, Takuya; Ando, Eriko; Hirai, Shinya; Fukushima, Shunji; Ogawa, Takumi

2013-04-01

The conventional 2D-analysis methods for occlusal contacts provided limited information on tooth morphology. This present study aims to detect 3D positional information of occlusal contacts from 2D-photos via photogrammetry. We propose an image processing solution for analysis of occlusal contacts and facets via the black silicone method and a photogrammetric technique. The occlusal facets were reconstructed from a 2D-photograph data-set of inter-occlusal records into a 3D image via photogrammetry. The configuration of the occlusal surface was reproduced with polygons. In addition, the textures of the occlusal contacts were mapped to each polygon. DIFFERENCE FROM CONVENTIONAL METHODS: Constructing occlusal facets with 3D polygons from 2D-photos with photogrammetry was a defining characteristic of this image processing technique. It allowed us to better observe findings of the black silicone method. Compared with conventional 3D analysis using a 3D scanner, our 3D models did not reproduce the detail of the anatomical configuration. However, by merging the findings of the inter-occlusal record, the deformation of mandible and the displacement of periodontal ligaments under occlusal force were reflected in our model. EFFECT OR PERFORMANCE: Through the use of polygons in the conversion of 2D images to 3D images, we were able to define the relation between the location and direction of the occlusal contacts and facets, which was difficult to detect via conventional methods. Through our method of making a 3D polygon model, the findings of inter-occlusal records which reflected the jaw/teeth behavior under occlusal force could be observed 3-dimensionally. Copyright © 2012 Japan Prosthodontic Society. Published by Elsevier Ltd. All rights reserved.

A retrospective study of a new n-butyl-2-cyanoacrylate glue ablation catheter incorporated with application guiding light for the treatment of venous insufficiency: Twelve-month results.

PubMed

Yavuz, Turhan; Acar, Altay Nihat; Aydın, Huseyin; Ekingen, Evren

2018-01-01

Objective This study aims to present the early results of a retrospective study of the use of novel n-butyl-2-cyanoacrylate (VenaBlock)-based nontumescent endovenous ablation with a guiding light for the treatment of patients with varicose veins. Methods Patients with lower limb venous insufficiency were treated with n-butyl-2-cyanoacrylate (VenaBlock Venous Closure System) between April 2016 and July 2016. The study enrolled adults aged 21-70 years with symptomatic moderate to severe varicosities (C2-C4b) and great saphenous vein reflux lasting longer than 0.5 s with great saphenous vein diameter between 5.5 and 15 mm assessed in the standing position. No compression stockings were used after the procedure. Duplex ultrasound imaging and clinical follow-up were performed on the third day, first month, sixth month, and 12th month. Clinical, etiological, anatomical, pathophysiological classification; venous clinical severity score; and completed Aberdeen varicose vein questionnaire were recorded. Results Five hundred thirty-eight patients with great saphenous vein incompetency underwent n-butyl-2-cyanoacrylate ablation. The mean ablation length was 25.69 ± 4.8 cm, and the average amount of n-butyl-2-cyanoacrylate delivered was 0.87 ± 0.15 ml. The mean procedure time was 11.7 ± 4.9 min. Procedural success was 100%, and complete occlusion was observed after treatment and at the third-day follow-up. We observed ecchymosis in five patients (1.00%) at the entry site at the third-day follow-up. Phlebitis was encountered with six (1.20%) patients. No skin pigmentation, hematoma, paresthesia, deep vein thrombosis, or pulmonary embolism was observed. Kaplan-Meier analysis yielded an occlusion rate of 99.4% at the 12-month follow-up. All patients had significant improvement in venous clinical severity score and Aberdeen varicose vein questionnaire scores postoperatively ( p <0.0001). Venous clinical severity score scores decreased from 5.43 ± 0.87 to

Venous pump of the calf: a study of venous and muscular pressures.

PubMed

Alimi, Y S; Barthelemy, P; Juhan, C

1994-11-01

Little data are available concerning the relation between the muscular pumping mechanism and the variation of superficial and deep venous pressure during normal action of the calf pump; therefore we undertook this study to determine the pressure values in three compartments of the calf and in the deep and the superficial venous system and to establish correlation between muscular and venous pressure. Nine healthy young women with a mean age of 23 years (range 19 to 28 years) were examined. In the same calf, a muscular catheter was placed in the deep posterior compartment (DPC), in the superficial posterior compartment (SPC), and in the anterior tibial compartment (ATC), and a vascular catheter was placed in the popliteal vein and in the greater saphenous vein (GSV). The five lines of pressure were simultaneously recorded in the following situations: at rest, during Valsalva maneuver, foot flexion, and foot extension. The situation was studied with the patient in the following positions: decubitus, sitting, standing, and squatting. A final continuous recording was carried out after the patient had been walking for 5 minutes. Mean values with standard errors of muscular and venous pressure were established in each situation. At rest and during Valsalva maneuver, the muscular pressures did not vary, whereas venous pressures increased significantly when the patient was sitting and standing. On the other hand, squatting was associated with a rise in the muscular and vein pressures. Foot flexion entailed a significant increase in the ATC pressure and a rise in the GSV pressure, whereas foot extension caused the DPC pressure to rise without venous pressure modifications. Walking was associated with an alternating increase in the DPC, SPC, GSV and popliteal vein pressures when the foot was compressed to floor followed by a significant decrease when the foot pressure was released. The variations in the deep and superficial venous pressures when the patient is sitting and

Combining central venous-to-arterial partial pressure of carbon dioxide difference and central venous oxygen saturation to guide resuscitation in septic shock.

PubMed

Du, Wei; Liu, Da-Wei; Wang, Xiao-Ting; Long, Yun; Chai, Wen-Zhao; Zhou, Xiang; Rui, Xi

2013-12-01

Central venous oxygen saturation (Scvo2) is a useful therapeutic target when treating septic shock. We hypothesized that combining Scvo2 and central venous-to-arterial partial pressure of carbon dioxide difference (△Pco2) may provide additional information about survival. We performed a retrospective analysis of 172 patients treated for septic shock. All patients were treated using goal-directed therapy to achieve Scvo2 ≥ 70%. After 6 hours of treatment, we divided patients into 4 groups based on Scvo2 (<70% or ≥ 70%) and △Pco2 (<6 mm Hg or ≥ 6 mm Hg). Overall, 28-day mortality was 35.5%. For patients in whom the Scvo2 target was not achieved at 6 hours, mortality was 50.0%, compared with 29.5% in those in whom Scvo2 exceeded 70% (P = .009). In patients with Scvo2 ≥ 70%, mortality was lower if △Pco2 was <6 mm Hg than if △Pco2 was ≥ 6 mm Hg (56.1% vs 16.1%, respectively; P < .001) and 6-hour lactate clearance was superior (0.01 ± 0.61 vs 0.21 ± 0.31, respectively; P = .016). The combination of Scvo2 and △Pco2 appears to predict outcome in critically ill patients resuscitated from septic shock better than Scvo2 alone. Patients who meet both targets appear to clear lactate more efficiently. © 2013.

Occlusal wear and occlusal condition in a convenience sample of young adults.

PubMed

Van't Spijker, A; Kreulen, C M; Bronkhorst, E M; Creugers, N H J

2015-01-01

To study progression of tooth wear quantitatively in a convenient sample of young adults and to assess possible correlations with occlusal conditions. Twenty-eight dental students participated in a three-year follow up study on tooth wear. Visible wear facets on full arch gypsum casts were assessed using a flatbed scanner and measuring software. Regression analyses were used to assess possible associations between the registered occlusal conditions 'occlusal guidance scheme', 'vertical overbite', 'horizontal overbite', 'depth of sagittal curve', 'canine Angle class relation', 'history of orthodontic treatment', and 'self-reported grinding/clenching' (independent variables) and increase of wear facets (dependent variable). Mean increase in facet surface areas ranged from 1.2 mm2 (premolars, incisors) to 3.4 mm2 (molars); the relative increase ranged from 15% to 23%. Backward regression analysis showed no significant relation for 'group function', 'vertical overbite', 'depth of sagittal curve', 'history of orthodontic treatment' nor 'self-reported clenching. The final multiple linear regression model showed significant associations amongst 'anterior protected articulation' and 'horizontal overbite' and increase of facet surface areas. For all teeth combined, only 'anterior protected articulation' had a significant effect. 'Self reported grinding' did not have a significant effect (p>0.07). In this study 'anterior protected articulation' and 'horizontal overbite', were significantly associated with the progression of tooth wear. Self reported grinding was not significantly associated with progression of tooth wear. Occlusal conditions such as anterior protected articulation and horizontal overbite seem to have an effect on the progression of occlusal tooth wear in this convenient sample of young adults. Copyright © 2014 Elsevier Ltd. All rights reserved.

Venous ulcer review

PubMed Central

Bevis, Paul; Earnshaw, Jonothan

2011-01-01

Clinical question: What is the best treatment for venous ulcers? Results: Compression aids ulcer healing. Pentoxifylline can aid ulcer healing. Artificial skin grafts are more effective than other skin grafts in helping ulcer healing. Correction of underlying venous incompetence reduces ulcer recurrence. Implementation: Potential pitfalls to avoid are: Failure to exclude underlying arterial disease before application of compression.Unusual-looking ulcers or those slow to heal should be biopsied to exclude malignant transformation. PMID:21673869

Hydrothorax after Central Venous Catheterization

PubMed Central

Rudge, C. J.; Bewick, M.; McColl, I.

1973-01-01

Three patients are described who developed hydrothorax as a complication of central venous catheterization. Respiratory distress associated with physical signs of fluid in the chest should arouse suspicion that the venous catheter has perforated the wall of the vein. The complications of central venous catheterization are reviewed and three cases of hydrothorax are presented. Comments on the prevention of these complications, their diagnosis and treatment if they occur, are made. ImagesFIG. 1FIG. 2 PMID:4717421

Detecting natural occlusion boundaries using local cues

PubMed Central

DiMattina, Christopher; Fox, Sean A.; Lewicki, Michael S.

2012-01-01

Occlusion boundaries and junctions provide important cues for inferring three-dimensional scene organization from two-dimensional images. Although several investigators in machine vision have developed algorithms for detecting occlusions and other edges in natural images, relatively few psychophysics or neurophysiology studies have investigated what features are used by the visual system to detect natural occlusions. In this study, we addressed this question using a psychophysical experiment where subjects discriminated image patches containing occlusions from patches containing surfaces. Image patches were drawn from a novel occlusion database containing labeled occlusion boundaries and textured surfaces in a variety of natural scenes. Consistent with related previous work, we found that relatively large image patches were needed to attain reliable performance, suggesting that human subjects integrate complex information over a large spatial region to detect natural occlusions. By defining machine observers using a set of previously studied features measured from natural occlusions and surfaces, we demonstrate that simple features defined at the spatial scale of the image patch are insufficient to account for human performance in the task. To define machine observers using a more biologically plausible multiscale feature set, we trained standard linear and neural network classifiers on the rectified outputs of a Gabor filter bank applied to the image patches. We found that simple linear classifiers could not match human performance, while a neural network classifier combining filter information across location and spatial scale compared well. These results demonstrate the importance of combining a variety of cues defined at multiple spatial scales for detecting natural occlusions. PMID:23255731

The effect of vein repair on the risk of venous thromboembolic events: a review of more than 100 traumatic military venous injuries.

PubMed

Quan, Reagan W; Gillespie, David L; Stuart, Rory P; Chang, Audrey S; Whittaker, David R; Fox, Charles J

2008-03-01

The management of venous trauma remains controversial. Critics of venous repair have cited an increased incidence of associated venous thromboembolic events with this management. We analyzed the current treatment of wartime venous injuries in United States military personnel in an effort to answer this question. From December 1, 2001, to October 31, 2005, all United States casualties with named venous injuries were evaluated. A retrospective review of a clinical database was performed on demographics, mechanism of injury, associated injuries, treatment, outcomes, and venous thromboembolic events. Data were analyzed using the Fisher exact test, analysis of variance, and logarithmic transformation. During this 5-year period, 82 patients sustained 103 named venous injuries due to combat operations. All patients were male, with an average age of 27.9 years (range, 20.3-58.3 years). Blast injuries accounted for 54 venous injuries (65.9%), gunshot wounds for 25 (30.5%), and motor vehicle accidents for 3 (3.6%). The venous injury was isolated in 28 patients (34.1%), and 16 (19.5%) had multiple venous injuries. The venous injury in two patients was associated with acute phlegmasia, with fractures in 33 (40.2%), and 22 (28.1%) sustained neurologic deficits. Venous injuries were treated by ligation in 65 patients (63.1%) and by open surgical repair in 38 (36.9%). Postoperative extremity edema occurred in all patients irrespective of method of management. Thrombosis after venous repair occurred in six of the 38 cases (15.8%). Pulmonary emboli developed in three patients, one after open repair and two after ligation (P > .99). In the largest review of military venous trauma in more than three decades, we found no difference in the incidence of venous thromboembolic complications between venous injuries managed by open repair vs ligation. Blast injuries of the extremities have caused most of the venous injuries. Ligation is the most common modality of treatment in combat zones

Occlusal adjustment using the bite plate-induced occlusal position as a reference position for temporomandibular disorders: a pilot study

PubMed Central

2010-01-01

Background Many researchers have not accepted the use of occlusal treatments for temporomandibular disorders (TMDs). However, a recent report described a discrepancy between the habitual occlusal position (HOP) and the bite plate-induced occlusal position (BPOP) and discussed the relation of this discrepancy to TMD. Therefore, the treatment outcome of evidence-based occlusal adjustments using the bite plate-induced occlusal position (BPOP) as a muscular reference position should be evaluated in patients with TMD. Methods The BPOP was defined as the position at which a patient voluntarily closed his or her mouth while sitting in an upright posture after wearing an anterior flat bite plate for 5 minutes and then removing the plate. Twenty-one patients with TMDs underwent occlusal adjustment using the BPOP. The occlusal adjustments were continued until bilateral occlusal contacts were obtained in the BPOP. The treatment outcomes were evaluated using the subjective dysfunction index (SDI) and the Helkimo Clinical Dysfunction Index (CDI) before and after the occlusal adjustments; the changes in these two indices between the first examination and a one-year follow-up examination were then analyzed. In addition, the difference between the HOP and the BPOP was three-dimensionally measured before and after the treatment. Results The percentage of symptom-free patients after treatment was 86% according to the SDI and 76% according to the CDI. The changes in the two indices after treatment were significant (p < 0.001). The changes in the mean HOP-BPOP differences on the x-axis (mediolateral) and the y-axis (anteroposterior) were significant (p < 0.05), whereas the change on the z-axis (superoinferior) was not significant (p > 0.1). Conclusion Although the results of the present study should be confirmed in other studies, a randomized clinical trial examining occlusal adjustments using the BPOP as a reference position appears to be warranted. PMID:20346167

A Predictive Framework to Elucidate Venous Stenosis: CFD & Shape Optimization.

PubMed

Javid Mahmoudzadeh Akherat, S M; Cassel, Kevin; Boghosian, Michael; Hammes, Mary; Coe, Fredric

2017-07-01

The surgical creation of vascular accesses for renal failure patients provides an abnormally high flow rate conduit in the patient's upper arm vasculature that facilitates the hemodialysis treatment. These vascular accesses, however, are very often associated with complications that lead to access failure and thrombotic incidents, mainly due to excessive neointimal hyperplasia (NH) and subsequently stenosis. Development of a framework to monitor and predict the evolution of the venous system post access creation can greatly contribute to maintaining access patency. Computational fluid dynamics (CFD) has been exploited to inspect the non-homeostatic wall shear stress (WSS) distribution that is speculated to trigger NH in the patient cohort under investigation. Thereafter, CFD in liaison with a gradient-free shape optimization method has been employed to analyze the deformation modes of the venous system enduring non-physiological hemodynamics. It is observed that the optimally evolved shapes and their corresponding hemodynamics strive to restore the homeostatic state of the venous system to a normal, pre-surgery condition. It is concluded that a CFD-shape optimization coupling that seeks to regulate the WSS back to a well-defined physiological WSS target range can accurately predict the mode of patient-specific access failure.

Stent Graft in Managing Juxta-Renal Aortoiliac Occlusion

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

Prabhudesai, V., E-mail: v_prabhudesai@hotmail.com; Mitra, K.; West, D. J.

2003-09-15

Endovascular procedures are frequently used as an alternative to surgical bypass in aortic and iliac occlusion. Stents have revolutionized the scope of such endovascular procedures, but there are few reports of stents or stent grafts in occlusive juxta-renal aortic occlusion. We present a case where such occlusion was managed by use of a stent graft with successful outcome.

A survey of the European Venous Forum on education and training in venous surgery and phlebology in Europe.

PubMed

Spanos, K; De Maeseneer, M; Nicolaides, A; Giannoukas, A D

2015-04-01

Venous training in Europe is lacking a formal curriculum among various specialties related to management of venous diseases. We conducted a survey in order to have a snapshot on the actual education and training level among physicians practicing currently venous surgery and phlebology in Europe. From April 7, 2014 to June 11, 2014 a survey was carried out using the Survey Monkey system, including 11 main questions covering all the domains of training and education in venous surgery and phlebology. The questionnaire was sent to all physicians included in the current mailing list of the European Venous Forum (EVF) and the Mediterranean League of Angiology and Vascular Surgery. Two questions were particularly addressed to those physicians who had attended the EVF hands-on workshop (HOW) at least once. The response rate was 24% (97/400) and 51.5% of them were practicing in a hospital service. Most responders were vascular surgeons (67.7%), followed by angiologists (19.4%). Only half of the responders felt as being competent to manage the whole spectrum of venous diseases successfully after completion of their training, while a few were able to perform endovenous ablations and even less more advanced venous interventions. Formal training in Duplex ultrasound was undertaken only in 55.2%. The majority suggested that a venous training program should be a separate part of their specialty rotation and should be organized at a national or European level, or even by a specific scientific society. Over 95% of those physicians who already participated in the EVF HOW considered the knowledge they acquired there as useful for their practice. There is currently an important need for more specialized venous training for all physicians involved in the diagnosis and management of venous diseases. Therefore all local, national and international initiatives should be encouraged to improve education in this field.

21 CFR 878.4020 - Occlusive wound dressing.

Code of Federal Regulations, 2011 CFR

2011-04-01

... 21 Food and Drugs 8 2011-04-01 2011-04-01 false Occlusive wound dressing. 878.4020 Section 878...) MEDICAL DEVICES GENERAL AND PLASTIC SURGERY DEVICES Surgical Devices § 878.4020 Occlusive wound dressing. (a) Identification. An occlusive wound dressing is a nonresorbable, sterile or non-sterile device...

21 CFR 878.4020 - Occlusive wound dressing.

Code of Federal Regulations, 2010 CFR

2010-04-01

... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Occlusive wound dressing. 878.4020 Section 878...) MEDICAL DEVICES GENERAL AND PLASTIC SURGERY DEVICES Surgical Devices § 878.4020 Occlusive wound dressing. (a) Identification. An occlusive wound dressing is a nonresorbable, sterile or non-sterile device...

Acute left main coronary artery occlusion

PubMed Central

Burgazli, K. Mehmet; Bilgin, Mehmet; Soydan, Nedim; Chasan, Ridvan; Erdogan, Ali

2013-01-01

The treatment of an acute left main coronary artery occlusion still poses a challenge. In this case report we present a 50-year-old patient with an acute occlusion of the left main artery. After a successful angioplasty without “stenting” due to the complexity of the stenosis the patient underwent a successful bypass surgery. We discuss the therapeutic options of acute left main occlusion regarding medical, interventional and surgical options. PMID:24353543

[Injuries to blood vessels near the heart caused by central venous catheters].

PubMed

Abram, J; Klocker, J; Innerhofer-Pompernigg, N; Mittermayr, M; Freund, M C; Gravenstein, N; Wenzel, V

2016-11-01

Injuries to blood vessels near the heart can quickly become life-threatening and include arterial injuries during central venous puncture, which can lead to hemorrhagic shock. We report 6 patients in whom injury to the subclavian artery and vein led to life-threatening complications. Central venous catheters are associated with a multitude of risks, such as venous thrombosis, air embolism, systemic or local infections, paresthesia, hemothorax, pneumothorax, and cervical hematoma, which are not always immediately discernible. The subclavian catheter is at a somewhat lower risk of catheter-associated sepsis and symptomatic venous thrombosis than approaches via the internal jugular and femoral veins. Indeed, access via the subclavian vein carries a substantial risk of pneumo- and hemothorax. Damage to the subclavian vein or artery can also occur during deliberate and inadvertent punctures and result in life-threatening complications. Therefore, careful consideration of the access route is required in relation to the patient and the clinical situation, to keep the incidence of complications as low as possible. For catheterization of the subclavian vein, puncture of the axillary vein in the infraclavicular fossa is a good alternative, because ultrasound imaging of the target vessel is easier than in the subclavian vein and the puncture can be performed much further from the lung.

Inheritance of Occlusal Topography: A Twin Study

PubMed Central

Su, C-Y.; Corby, P.M.; Elliot, M.A.; Studen-Pavlovich, D.A.; Ranalli, D.N.; Rosa, B.; Wessel, J.; Schork, N.J.; Hart, T.C.; Bretz, W.A.

2011-01-01

Aim This was to determine the relative contribution of genetic factors on the morphology of occlusal surfaces of mandibular primary first molars by employing the twin study model. Methods The occlusal morphology of mandibular primary first molar teeth from dental casts of 9 monozygotic (MZ) twin pairs and 12 dizygotic (DZ) twin pairs 4 to 7 years old, were digitized by contact-type three-dimensional (3D) scanner. To compare the similarity of occlusal morphology between twin sets, each twin pair of occlusal surfaces was superimposed to establish the best fit by using computerized least squared techniques. Heritability was computed using a variance component model, adjusted for age and gender. Results DZ pairs demonstrated a greater degree of occlusal morphology variance. The total amount of difference in surface overlap was 0.0508 mm (0.0018 (inches) for the MZ (n=18) sample and 0.095 mm (0.0034 inches) for the DZ (n=24) sample and were not statistically significant (p=0.2203). The transformed mean differences were not statistically significantly different (p=0.2203). Heritability estimates of occlusal surface areas for right and left mandibular primary first molars were 97.5% and 98.2% (p<0.0001), respectively. Conclusions Occlusal morphology of DZ twin pairs was more variable than that of MZ twin pairs. Heritability estimates revealed that genetic factors strongly influence occlusal morphology of mandibular primary first molars. PMID:18328234

Clinical features of venous insufficiency and the risk of venous thrombosis in older people.

PubMed

Engbers, Marissa J; Karasu, Alev; Blom, Jeanet W; Cushman, Mary; Rosendaal, Frits R; van Hylckama Vlieg, Astrid

2015-11-01

Venous thrombosis is common in older age, with an incidence of 0·5-1% per year in those aged >70 years. Stasis of blood flow is an important contributor to the development of thrombosis and may be due to venous insufficiency in the legs. The risk of thrombosis associated with clinical features of venous insufficiency, i.e., varicose veins, leg ulcers and leg oedema, obtained with a standardized interview was assessed in the Age and Thrombosis Acquired and Genetic risk factors in the Elderly (AT-AGE) study. The AT-AGE study is a case-control study in individuals aged 70 years and older (401 cases with a first-time venous thrombosis and 431 control subjects). We calculated odds ratios (ORs) and corresponding 95% confidence intervals (CI) adjusted for age, sex and study centre. Varicose veins and leg ulcer were associated with a 1·6-fold (95% CI 1·2-2·3) and 3·3-fold increased risk of thrombosis (95% CI 1·6-6·7), respectively, while the risk was increased 3·0-fold (95% CI 2·1-4·5) in the presence of leg oedema. The risk of thrombosis was highest when all three risk factors occurred simultaneously (OR: 10·5; 95% CI 1·3-86·1). In conclusion, clinical features of venous insufficiency, i.e., varicose veins, leg ulcers and leg oedema, are risk factors for venous thrombosis in older people. © 2015 John Wiley & Sons Ltd.

Effects of parasagittal meningiomas on intracranial venous circulation assessed by the virtual reality technology.

PubMed

Wang, Shousen; Ying, Jianbin; Wei, Liangfeng; Li, Shiqing; Jing, Junjie

2015-01-01

This study is to investigate the compensatory intracranial venous pathways in parasagittal meningiomas (PSM) patients by virtual reality technology. A total of 48 PSM patients (tumor group) and 20 patients with trigeminal neuralgia and hemifacial spasm but without intracranial venous diseases (control group) were enrolled. All patients underwent 3D CE-MRV examination. The 3D reconstructed images by virtual reality technology were used for assessment of diameter and number of intracranial veins, tumor location, venous sinus invasion degree and collateral circulation formation. Diameter of bridging veins in posterior 1/3 superior sagittal sinus (SSS) in tumor group was significantly smaller than that of the control group (P < 0.05). For tumors located in mid 1/3 SSS, diameter of bridging veins and vein of Labbé (VL) in posterior 1/3 SSS decreased significantly (P < 0.05). For tumors located in posterior 1/3 SSS, bridging vein number and transverse sinus (TS) diameter significantly decreased while superficial Sylvian vein (SSV) diameter increased significantly (P < 0.05). Compared with tumor in posterior 1/3 SSS subgroup, number of bridging veins in the tumor in mid 1/3 SSS subgroup increased significantly (P < 0.05). Compared with control group, only the bridging vein number in anterior 1/3 SSS segment in invasion Type 3-4 tumor subgroup decreased significantly (P < 0.05). Diameter of TS and bridging veins in posterior 1/3 SSS segment in sinus invasion Type 5-6 tumor subgroup decreased significantly (P < 0.05). Compared with control group, only the diameter of VL and TS of collateral circulation Grade 1 tumor subgroup decreased significantly (P < 0.05) while in Grade 3 tumor subgroup, TS diameter decreased and SSV diameter increased significantly (P < 0.05). The intracranial blood flow is mainly drained through SSV drainage after SSS occlusion by PSM.

Effects of parasagittal meningiomas on intracranial venous circulation assessed by the virtual reality technology

PubMed Central

Wang, Shousen; Ying, Jianbin; Wei, Liangfeng; Li, Shiqing; Jing, Junjie

2015-01-01

Objective: This study is to investigate the compensatory intracranial venous pathways in parasagittal meningiomas (PSM) patients by virtual reality technology. Methods: A total of 48 PSM patients (tumor group) and 20 patients with trigeminal neuralgia and hemifacial spasm but without intracranial venous diseases (control group) were enrolled. All patients underwent 3D CE-MRV examination. The 3D reconstructed images by virtual reality technology were used for assessment of diameter and number of intracranial veins, tumor location, venous sinus invasion degree and collateral circulation formation. Results: Diameter of bridging veins in posterior 1/3 superior sagittal sinus (SSS) in tumor group was significantly smaller than that of the control group (P < 0.05). For tumors located in mid 1/3 SSS, diameter of bridging veins and vein of Labbé (VL) in posterior 1/3 SSS decreased significantly (P < 0.05). For tumors located in posterior 1/3 SSS, bridging vein number and transverse sinus (TS) diameter significantly decreased while superficial Sylvian vein (SSV) diameter increased significantly (P < 0.05). Compared with tumor in posterior 1/3 SSS subgroup, number of bridging veins in the tumor in mid 1/3 SSS subgroup increased significantly (P < 0.05). Compared with control group, only the bridging vein number in anterior 1/3 SSS segment in invasion Type 3-4 tumor subgroup decreased significantly (P < 0.05). Diameter of TS and bridging veins in posterior 1/3 SSS segment in sinus invasion Type 5-6 tumor subgroup decreased significantly (P < 0.05). Compared with control group, only the diameter of VL and TS of collateral circulation Grade 1 tumor subgroup decreased significantly (P < 0.05) while in Grade 3 tumor subgroup, TS diameter decreased and SSV diameter increased significantly (P < 0.05). Conclusions: The intracranial blood flow is mainly drained through SSV drainage after SSS occlusion by PSM. PMID:26550184

A comparison of liver function after hepatectomy with inflow occlusion between sevoflurane and propofol anesthesia.

PubMed

Song, J C; Sun, Y M; Yang, L Q; Zhang, M Z; Lu, Z J; Yu, W F

2010-10-01

In this study, we compared liver function tests after hepatectomy with inflow occlusion as a function of propofol versus sevoflurane anesthesia. One hundred patients undergoing elective liver resection with inflow occlusion were randomized into a sevoflurane group or a propofol group. General anesthesia was induced with 3 μg/kg fentanyl, 0.2 mg/kg cisatracurium, and target-controlled infusion of propofol, set at a plasma target concentration of 4 to 6 μg/mL, or sevoflurane initially started at 8%. Anesthesia was maintained with target-controlled infusion of propofol (2-4 μg/mL) or sevoflurane (1.5%-2.5%). The primary end point was postoperative liver injury assessed by peak values of liver transaminases. Transaminase levels peaked between the first and the third postoperative day. Peak alanine aminotransferase was 504 and 571 U/L in the sevoflurane group and the propofol group, respectively. Peak aspartate aminotransferase was 435 U/L after sevoflurane and 581 U/L in the propofol group. There were no significant differences in peak alanine aminotransferase or peak aspartate aminotransferase between groups. Other liver function tests including bilirubin and alkaline phosphatase, and peak values of white blood cell counts and creatinine, were also not different between groups. Sevoflurane and propofol anesthetics resulted in similar patterns of liver function tests after hepatectomy with inflow occlusion. These data suggest that the 2 anesthetics are equivalent in this clinical context.

Current concepts in repair of extremity venous injury.

PubMed

Williams, Timothy K; Clouse, W Darrin

2016-04-01

Extremity venous injury management remains controversial. The purpose of this communication is to offer perspective as well as experiential and technical insight into extremity venous injury repair. Available literature is reviewed and discussed. Historical context is provided. Indication, the decision process for repair, including technical conduct, is delineated. In particular, the authors' experiences in both civilian and wartime injury are used for perspective. Extremity venous injury repair was championed within data from the Vietnam Vascular Registry. However, patterns of extremity venous injury differ between combat and civilian settings. Since Vietnam, civilian descriptive series opine the benefits and potential complications associated with both venous injury repair and ligation. These surround extremity edema, chronic venous insufficiency, thromboembolism, and limb loss. Whereas no clear superiority in either approach has been identified to date, there appears to be no increased risk of pulmonary embolism or chronic venous changes with repair. Newer data from the wars in Iraq and Afghanistan and meta-analysis have reinforced this and also have suggested limb salvage benefit for extremity venous repair in combined arterial and venous injuries in modern settings. The patient's physiologic state and associated injury drive five triage categories suggesting vein injury management. Vein repair thrombosis occurs in a significant proportion, yet many recanalize and possibly have a positive impact on limb venous return. Further, early decompression favors reduced blood loss, acute edema, and inflammation, supporting collateral development. Large soft tissue injury minimizing collateral capacity increases the importance of repair. Constructs of repair are varied with modest differences in patency. Venous shunting is feasible, but specific roles remain nebulous. An aggressive posture toward extremity venous injury repair seems justified today because of the likely

Percutaneous Endovascular Salvage Techniques for Implanted Venous Access Device Dysfunction

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

Breault, Stéphane, E-mail: stephane.breault@chuv.ch; Glauser, Frédéric, E-mail: frederic.glauser@chuv.ch; Babaker, Malik, E-mail: malik.babaker@chuv.ch

2015-06-15

PurposeImplanted venous access devices (IVADs) are often used in patients who require long-term intravenous drug administration. The most common causes of device dysfunction include occlusion by fibrin sheath and/or catheter adherence to the vessel wall. We present percutaneous endovascular salvage techniques to restore function in occluded catheters. The aim of this study was to evaluate the feasibility, safety, and efficacy of these techniques.Methods and MaterialsThrough a femoral or brachial venous access, a snare is used to remove fibrin sheath around the IVAD catheter tip. If device dysfunction is caused by catheter adherences to the vessel wall, a new “mechanical adhesiolysis”more » maneuver was performed. IVAD salvage procedures performed between 2005 and 2013 were analyzed. Data included clinical background, catheter tip position, success rate, recurrence, and rate of complication.ResultsEighty-eight salvage procedures were performed in 80 patients, mostly women (52.5 %), with a mean age of 54 years. Only a minority (17.5 %) of evaluated catheters were located at an optimal position (i.e., cavoatrial junction ±1 cm). Mechanical adhesiolysis or other additional maneuvers were used in 21 cases (24 %). Overall technical success rate was 93.2 %. Malposition and/or vessel wall adherences were the main cause of technical failure. No complications were noted.ConclusionThese IVAD salvage techniques are safe and efficient. When a catheter is adherent to the vessel wall, mechanical adhesiolysis maneuvers allow catheter mobilization and a greater success rate with no additional risk. In patients who still require long-term use of their IVAD, these procedures can be performed safely to avoid catheter replacement.« less

Geo-Referenced Dynamic Pushbroom Stereo Mosaics for 3D and Moving Target Extraction - A New Geometric Approach

DTIC Science & Technology

2009-12-01

facilitating reliable stereo matching, occlusion handling, accurate 3D reconstruction and robust moving target detection . We use the fact that all the...a moving platform, we will have to naturally and effectively handle obvious motion parallax and object occlusions in order to be able to detect ...facilitating reliable stereo matching, occlusion handling, accurate 3D reconstruction and robust moving target detection . Based on the above two

Neuromuscular dentistry: Occlusal diseases and posture.

PubMed

Khan, Mohd Toseef; Verma, Sanjeev Kumar; Maheshwari, Sandhya; Zahid, Syed Naved; Chaudhary, Prabhat K

2013-01-01

Neuromuscular dentistry has been a controversial topic in the field of dentistry and still remains debatable. The issue of good occlusion and sound health has been repeatedly discussed. Sometimes we get complains of sensitive teeth and sometimes of tired facial muscles on getting up in the morning. Owing to the intimate relation of masticatory apparatus with the cranium and cervico-scapular muscular system, the disorders in any system, draw attention from concerned clinicians involved in management, to develop an integrated treatment protocol for the suffering patients. There may be patients reporting to the dental clinics after an occlusal restoration or extraction, having pain in or around the temporomandibular joint, headache or neck pain. Although their esthetic demands must not be undermined during the course of treatment plan, whenever dental treatment of any sort is planned, occlusion/bite should be given prime importance. Very few dentist are able to diagnose the occlusal disease and of those who diagnose many people resort to aggressive treatment modalities. This paper aims to report the signs of occlusal disease, and discuss their association with TMDs and posture.

Central venous catheter-associated bloodstream infections in a pediatric intensive care unit: effect of the location of catheter insertion.

PubMed

Krishnaiah, Anil; Soothill, James; Wade, Angie; Mok, Quen Q; Ramnarayan, Padmanabhan

2012-05-01

To compare the rate of central venous catheter-associated bloodstream infections between pediatric intensive care unit admissions where central venous catheters were inserted within the same hospital (internal central venous catheters) and those where central venous catheters were inserted before transfer from other hospitals (external central venous catheters). Retrospective analysis of prospectively collected data. A tertiary care pediatric intensive care unit in London, UK. Consecutive pediatric intensive care unit admissions between May 2007 and March 2009. None. Catheter-associated bloodstream infections were identified using a widely accepted surveillance definition. The rate and time to occurrence of catheter-associated bloodstream infection were compared between internal and external nontunneled central venous catheters. A multilevel Cox-regression model was used to study the association between location of central venous catheter insertion and time to catheter-associated bloodstream infection. In total, 382 central venous catheters were studied (245 internal; 137 external) accounting for a total of 1,737 central venous catheter days. There was a higher catheter-associated bloodstream infection incidence density among external central venous catheters (23.1 [95% confidence interval 11.0-35.2] vs. 9.7 [95% confidence interval 3.9-15.5] per 1,000 catheter-days). Multivariable analyses demonstrated higher infection risk with external central venous catheters (hazard ratio 2.65 [95% confidence interval 1.18-5.96]) despite adjustment for confounding variables. The rate of catheter-associated bloodstream infections in the pediatric intensive care unit is significantly affected by external insertion of the central venous catheter. Future interventions to reduce nosocomial infections on pediatric intensive care units will need to be specifically targeted at this high-risk patient group.

21 CFR 870.1140 - Venous blood pressure manometer.

Code of Federal Regulations, 2014 CFR

2014-04-01

... 21 Food and Drugs 8 2014-04-01 2014-04-01 false Venous blood pressure manometer. 870.1140 Section... (CONTINUED) MEDICAL DEVICES CARDIOVASCULAR DEVICES Cardiovascular Diagnostic Devices § 870.1140 Venous blood pressure manometer. (a) Identification. A venous blood pressure manometer is a device attached to a venous...

21 CFR 870.1140 - Venous blood pressure manometer.

Code of Federal Regulations, 2012 CFR

2012-04-01

... 21 Food and Drugs 8 2012-04-01 2012-04-01 false Venous blood pressure manometer. 870.1140 Section... (CONTINUED) MEDICAL DEVICES CARDIOVASCULAR DEVICES Cardiovascular Diagnostic Devices § 870.1140 Venous blood pressure manometer. (a) Identification. A venous blood pressure manometer is a device attached to a venous...

21 CFR 870.1140 - Venous blood pressure manometer.

Code of Federal Regulations, 2013 CFR

2013-04-01

... 21 Food and Drugs 8 2013-04-01 2013-04-01 false Venous blood pressure manometer. 870.1140 Section... (CONTINUED) MEDICAL DEVICES CARDIOVASCULAR DEVICES Cardiovascular Diagnostic Devices § 870.1140 Venous blood pressure manometer. (a) Identification. A venous blood pressure manometer is a device attached to a venous...

21 CFR 870.1140 - Venous blood pressure manometer.

Code of Federal Regulations, 2011 CFR

2011-04-01

... 21 Food and Drugs 8 2011-04-01 2011-04-01 false Venous blood pressure manometer. 870.1140 Section... (CONTINUED) MEDICAL DEVICES CARDIOVASCULAR DEVICES Cardiovascular Diagnostic Devices § 870.1140 Venous blood pressure manometer. (a) Identification. A venous blood pressure manometer is a device attached to a venous...

Thermographic venous blood flow characterization with external cooling stimulation

NASA Astrophysics Data System (ADS)

Saxena, Ashish; Ng, E. Y. K.; Raman, Vignesh

2018-05-01

Experimental characterization of blood flow in a human forearm is done with the application of continuous external cooling based active thermography method. Qualitative and quantitative detection of the blood vessel in a thermal image is done, along with the evaluation of blood vessel diameter, blood flow direction, and velocity in the target blood vessel. Subtraction based image manipulation is performed to enhance the feature contrast of the thermal image acquired after the removal of external cooling. To demonstrate the effect of occlusion diseases (obstruction), an external cuff based occlusion is applied after the removal of cooling and its effect on the skin rewarming is studied. Using external cooling, a transit time method based blood flow velocity estimation is done. From the results obtained, it is evident that an external cooling based active thermography method can be used to develop a diagnosis tool for superficial blood vessel diseases.

Longitudinal Volume Quantification of Deep Medullary Veins in Patients with Cerebral Venous Sinus Thrombosis : Venous Volume Assessment in Cerebral Venous Sinus Thrombosis Using SWI.

PubMed

Dempfle, A K; Harloff, A; Schuchardt, F; Bäuerle, J; Yang, S; Urbach, H; Egger, K

2017-06-06

Susceptibility-weighted imaging (SWI) visualizes small cerebral veins with high sensitivity and could, thus, enable quantification of hemodynamics of deep medullary veins. We aimed to evaluate volume changes of deep medullary veins in patients with acute cerebral venous sinus thrombosis (CVST) over time in comparison to healthy controls. All magnetic resonance imaging (MRI) experiments were executed at 3 T using a 32-channel head coil. Based on SWI and semiautomatic postprocessing (statistical parametric mapping [SPM8] and ANTs), the volume of deep medullary veins was quantified in 14 patients with acute CVST at baseline and the 6‑month follow-up, as well as in 13 healthy controls undergoing repeated MRI examination with an interscan interval of at least 1 month. Deep medullary venous volume change over time was significantly different between healthy controls and patient groups (p < 0.001). Patients with superior sagittal sinus thrombosis (SSST) showed a significant decline from baseline to follow-up measurements (9.8 ± 4.9 ml versus 7.5 ± 4.2 ml; p = 0.02), whereas in patients with transverse sinus thrombosis (TST) and healthy controls no significant volume changes were observable. Venous volume quantification was feasible and reproducible both in healthy volunteers and in patients. The decrease of venous volume in patients over time represents improvement of venous drainage, reduction of congestion, and normalization of microcirculation due to treatment. Thus, quantification of venous microcirculation could be valuable for estimation of prognosis and guidance of CVST therapy in the future.

Vacuum-assisted venous return reduces blood usage.

PubMed

Banbury, Michael K; White, Jennifer A; Blackstone, Eugene H; Cosgrove, Delos M

2003-09-01

To determine whether vacuum-assisted venous return has clinical advantages over conventional gravity drainage apart from allowing the use of smaller cannulas and shorter tubing. A total of 150 valve operations were performed at our institution between February and July 1999 using vacuum-assisted venous return with small venous cannulas connected to short tubing. These were compared with (1) 83 valve operations performed between April 1997 and January 1998 using the initial version of vacuum-assisted venous return, and (2) 124 valve operations performed between January and April of 1997 using conventional gravity drainage. Priming volume, hematocrit value, red blood cell usage, and total blood product usage were compared multivariably. These comparisons were covariate and propensity adjusted for dissimilarities between the groups and confirmed by propensity-matched pairs analysis. Priming volume was 1.4 +/- 0.4 L for small-cannula vacuum-assisted venous return, 1.7 +/- 0.4 L for initial vacuum-assisted venous return, and 2.0 +/- 0.4 L for gravity drainage (P <.0001). Smaller priming resulted in higher hematocrit values both at the beginning of cardiopulmonary bypass (27% +/- 5% compared with 26% +/- 4% and 25% +/- 4%, respectively, P <.0001) and at the end (30% +/- 4% compared with 28% +/- 4% and 27% +/- 4%, respectively, P <.0001). Red cell transfusions were used in 17% of the patients having small-cannula vacuum-assisted venous return, 27% of the initial patients having vacuum-assisted venous return, and 37% of the patients having gravity drainage (P =.001); total blood product usage was 19%, 27%, and 39%, respectively (P =.002). Although ministernotomy also was associated with reduced blood product usage (P <.004), propensity matching on type of sternotomy confirmed the association of vacuum-assisted venous return with lowered blood product usage. Vacuum-assisted venous return results in (1) higher hematocrit values during cardiopulmonary bypass and (2) decreased

Tracking Multiple Video Targets with an Improved GM-PHD Tracker

PubMed Central

Zhou, Xiaolong; Yu, Hui; Liu, Honghai; Li, Youfu

2015-01-01

Tracking multiple moving targets from a video plays an important role in many vision-based robotic applications. In this paper, we propose an improved Gaussian mixture probability hypothesis density (GM-PHD) tracker with weight penalization to effectively and accurately track multiple moving targets from a video. First, an entropy-based birth intensity estimation method is incorporated to eliminate the false positives caused by noisy video data. Then, a weight-penalized method with multi-feature fusion is proposed to accurately track the targets in close movement. For targets without occlusion, a weight matrix that contains all updated weights between the predicted target states and the measurements is constructed, and a simple, but effective method based on total weight and predicted target state is proposed to search the ambiguous weights in the weight matrix. The ambiguous weights are then penalized according to the fused target features that include spatial-colour appearance, histogram of oriented gradient and target area and further re-normalized to form a new weight matrix. With this new weight matrix, the tracker can correctly track the targets in close movement without occlusion. For targets with occlusion, a robust game-theoretical method is used. Finally, the experiments conducted on various video scenarios validate the effectiveness of the proposed penalization method and show the superior performance of our tracker over the state of the art. PMID:26633422

Intraatrial baffle repair of anomalous systemic venous return without hepatic venous drainage in heterotaxy syndrome.

PubMed

Turkoz, Riza; Ayabakan, Canan; Vuran, Can; Omay, Oğuz

2010-08-01

A 7-month-old boy with heterotaxy syndrome had partial atrioventricular septal defect and interrupted inferior vena cava with hemiazygos continuation to a left superior vena cava. The left side of the common atrium receiving all the venous drainage was in connection with the left ventricle and the aorta. The small atrium and the proximity of the pulmonary and hepatic vein orifices precluded complete baffling. This report describes an intraatrial baffle repair of anomalous systemic venous return without hepatic venous drainage. This resulted in good oxygenation postoperatively, with oxygen saturation ranging from 93% to 98%.

Human cerebral venous outflow pathway depends on posture and central venous pressure

PubMed Central

Gisolf, J; van Lieshout, J J; van Heusden, K; Pott, F; Stok, W J; Karemaker, J M

2004-01-01

Internal jugular veins are the major cerebral venous outflow pathway in supine humans. In upright humans the positioning of these veins above heart level causes them to collapse. An alternative cerebral outflow pathway is the vertebral venous plexus. We set out to determine the effect of posture and central venous pressure (CVP) on the distribution of cerebral outflow over the internal jugular veins and the vertebral plexus, using a mathematical model. Input to the model was a data set of beat-to-beat cerebral blood flow velocity and CVP measurements in 10 healthy subjects, during baseline rest and a Valsalva manoeuvre in the supine and standing position. The model, consisting of 2 jugular veins, each a chain of 10 units containing nonlinear resistances and capacitors, and a vertebral plexus containing a resistance, showed blood flow mainly through the internal jugular veins in the supine position, but mainly through the vertebral plexus in the upright position. A Valsalva manoeuvre while standing completely re-opened the jugular veins. Results of ultrasound imaging of the right internal jugular vein cross-sectional area at the level of the laryngeal prominence in six healthy subjects, before and during a Valsalva manoeuvre in both body positions, correlate highly with model simulation of the jugular cross-sectional area (R2 = 0.97). The results suggest that the cerebral venous flow distribution depends on posture and CVP: in supine humans the internal jugular veins are the primary pathway. The internal jugular veins are collapsed in the standing position and blood is shunted to an alternative venous pathway, but a marked increase in CVP while standing completely re-opens the jugular veins. PMID:15284348

Biomechanics of occlusion--implications for oral rehabilitation.

PubMed

Peck, C C

2016-03-01

The dental occlusion is an important aspect of clinical dentistry; there are diverse functional demands ranging from highly precise tooth contacts to large crushing forces. Further, there are dogmatic, passionate and often diverging views on the relationship between the dental occlusion and various diseases and disorders including temporomandibular disorders, non-carious cervical lesions and tooth movement. This study provides an overview of the biomechanics of the masticatory system in the context of the dental occlusion's role in function. It explores the adaptation and precision of dental occlusion, its role in bite force, jaw movement, masticatory performance and its influence on the oro-facial musculoskeletal system. Biomechanics helps us better understand the structure and function of biological systems and consequently an understanding of the forces on, and displacements of, the dental occlusion. Biomechanics provides insight into the relationships between the dentition, jaws, temporomandibular joints, and muscles. Direct measurements of tooth contacts and forces are difficult, and biomechanical models have been developed to better understand the relationship between the occlusion and function. Importantly, biomechanical research will provide knowledge to help correct clinical misperceptions and inform better patient care. The masticatory system demonstrates a remarkable ability to adapt to a changing biomechanical environment and changes to the dental occlusion or other components of the musculoskeletal system tend to be well tolerated. © 2015 John Wiley & Sons Ltd.

A failure of preoperative duplex imaging to diagnose a lower extremity venous aneurysm in a patient with severe chronic venous insufficiency.

PubMed

Jones, Roy Wesley; Parkerson, Godfrey Ross; Ottinger, Mary; Rodriguez, Eduardo; Park, Brian

2017-01-01

We present a case of recurrent bilateral lower extremity venous stasis ulcers in association with a superficial venous aneurysm at the right saphenofemoral junction that was misdiagnosed on preoperative duplex scanning. A 53-year-old female presented to our clinic with 6-year history of bilateral lower extremity venous stasis ulcers. Her past medical history was significant for refractory venous stasis ulcers of the bilateral lower extremities present for 6 years and morbid obesity. Preoperative venous duplex demonstrated severe venous insufficiency of the superficial and deep systems, but a venous aneurysm was not appreciated. During the high ligation of the right saphenofemoral junction, a 3 × 4 × 5 cm aneurysm was encountered. Repair consisted of aneurysm resection, high ligation of the greater saphenous vein, dissociation of the great saphenous and anterior saphenous veins, and stab phlebectomy of large varicose veins of the thigh and lower leg. The patient recovered uneventfully and experienced complete healing of the venous stasis ulcer in several weeks. Superficial venous aneurysms of the lower extremity are rare and can be often missed on preoperative duplex ultrasound imaging. Large diameter measurements of the proximal greater saphenous vein and obesity increase the risk of misdiagnosing venous aneurysms with duplex imaging; therefore, clinical suspicion must remain high. These aneurysms can be associated with significant symptoms for which repair is indicated.

Dental occlusion and temporomandibular disorders.

PubMed

Stone, J Caitlin; Hannah, Andrew; Nagar, Nathan

2017-10-27

Data sourcesMedline, Scopus and Google Scholar.Study selectionTwo reviewers selected studies independently. English language clinical studies assessing the association between temporomandibular disorders (TMD) and features of dental occlusion were considered.Data extraction and synthesisStudy quality was assessed based on the Newcastle-Ottawa Scale (NOS) and a narrative synthesis was presented.ResultsIn all 25 studies (17 case-control, eight comparative) were included. Overall there was a high variability between occlusal features and TMD diagnosis. Findings were consistent with a lack of clinically relevant association between TMD and dental occlusion. Only two studies were associated with TMD in the majority (≥50%) of single variable analyses in patient populations. Only mediotrusive interferences are associated with TMD in the majority of multiple variable analyses.ConclusionsThe findings support the absence of a disease-specific association, there is no ground to hypothesise a major role for dental occlusion in the pathophysiology of TMDs. Dental clinicians are thus encouraged to move forward and abandon the old-fashioned gnathological paradig.

Conventional occlusion versus pharmacologic penalization for amblyopia.

PubMed

Li, Tianjing; Shotton, Kate

2009-10-07

Amblyopia is defined as defective visual acuity in one or both eyes without demonstrable abnormality of the visual pathway, and is not immediately resolved by wearing glasses. To assess the effectiveness and safety of conventional occlusion versus atropine penalization for amblyopia. We searched CENTRAL, MEDLINE, EMBASE, LILACS, the WHO International Clinical Trials Registry Platform, preference lists, science citation index and ongoing trials up to June 2009. We included randomized/quasi-randomized controlled trials comparing conventional occlusion to atropine penalization for amblyopia. Two authors independently screened abstracts and full text articles, abstracted data, and assessed the risk of bias. Three trials with a total of 525 amblyopic eyes were included. One trial was assessed as having a low risk of bias among these three trials, and one was assessed as having a high risk of bias.Evidence from three trials suggests atropine penalization is as effective as conventional occlusion. One trial found similar improvement in vision at six and 24 months. At six months, visual acuity in the amblyopic eye improved from baseline 3.16 lines in the occlusion and 2.84 lines in the atropine group (mean difference 0.034 logMAR; 95% confidence interval (CI) 0.005 to 0.064 logMAR). At 24 months, additional improvement was seen in both groups; but there continued to be no meaningful difference (mean difference 0.01 logMAR; 95% CI -0.02 to 0.04 logMAR). The second trial reported atropine to be more effective than occlusion. At six months, visual acuity improved 1.8 lines in the patching group and 3.4 lines in the atropine penalization group, and was in favor of atropine (mean difference -0.16 logMAR; 95% CI -0.23 to -0.09 logMAR). Different occlusion modalities were used in these two trials. The third trial had inherent methodological flaws and limited inference could be drawn.No difference in ocular alignment, stereo acuity and sound eye visual acuity between occlusion and

Necrotizing Fasciitis of the Periorbital Region Complicated by Combined Central Retinal Artery Occlusion, Central Retinal Vein Occlusion, and Posterior Ciliary Occlusion.

PubMed

Sultan, Harris; Malik, Amina; Li, Helen K; Chévez-Barrios, Patricia; Lee, Andrew G

A 50 year-old man on immunosuppressive agents presented with left eye vision loss, periorbital swelling, pain, and ophthalmoplegia. The patient was clinically found to have a central retinal artery and vein occlusion. A CT scan was performed which demonstrated intraorbital fat stranding, however the patient lacked sinus disease. The etiology of the orbital infection was held in question. The area was debrided in the operating room, and the specimen demonstrated group A streptococcal species consistent with necrotizing fasciitis. Periorbital necrotizing fasciitis should be suspected in patients with rapidly progressive orbital symptoms without sinus disease as lack of surgical intervention can result in poor outcomes. The unusual aspect to this case is the mechanism of vision loss, as the authors hypothesize that there was vascular infiltration of the infection resulting in the central retinal artery occlusion and central retinal vein occlusion which have not been previously reported secondary to necrotizing fasciitis of the orbit.

Outcomes of Stent Placement for Chronic Occlusion of a Filter-bearing Inferior Vena Cava in Patients with Severe Post-thrombotic Syndrome.

PubMed

Ye, K; Lu, X; Li, W; Yin, M; Liu, X; Qin, J; Liu, G; Jiang, M

2016-12-01

To evaluate the technical aspects and short-term clinical results of stent placement for chronic occlusion of a filter-bearing inferior vena cava (IVC) in patients with severe post-thrombotic syndrome (PTS). A retrospective analysis of 24 patients with severe PTS associated with occlusion of a filter-bearing IVC treated by stent placement was conducted at a single institution from January 2010 to December 2014. Patient-reported quality of life and limb Villalta scores were evaluated before and after treatment by questionnaire and clinical examination, respectively. Stent patency was evaluated by duplex Doppler ultrasound, venography, or venous computed tomographic (CT) angiography. All patients tolerated the procedure well. Nineteen patients with filter-bearing IVC and bilateral iliofemoral occlusions were treated with "double-barrel" stents, two were treated with fenestrated stents, and the remaining three patients were treated by unilateral stent placement of the iliofemoral vein and filter-bearing IVC. Quality of life and Villalta scores were significantly improved (p < .001) after the procedure. The 1-year, and 2-year cumulative primary and secondary stent patency rates were 67% and 91%, and 45% and 77%, respectively. During a median follow-up period of 27 months (range 3-55 months), the cumulative rates of complete relief of pain (visual analog scale >5) and swelling (grade 3) were 77% (13 of 17 limbs at risk) and 75% (24 of 32 limbs at risk), respectively. There were 23 limbs with active ulcers and the cumulative rate of ulcer healing at 2 years was 73%. There were no cases of clinical bleeding, symptomatic pulmonary embolism, or mortality. Recanalization of an occluded IVC filter and stent placement through the filter is a feasible and safe method for management of PTS associated with filter-bearing IVC occlusions, with acceptable short-term stent patency and clinical results. However, close follow-up after procedure is necessary because of a relatively

Anomalous pulmonary venous connection: An underestimated entity.

PubMed

Magalhães, Sara P; Moreno, Nuno; Loureiro, Marília; França, Manuela; Reis, Fernanda; Alvares, Sílvia; Ribeiro, Manuel

2016-12-01

Anomalous pulmonary venous connection is an uncommon congenital anomaly in which all (total form) or some (partial form) pulmonary veins drain into a systemic vein or into the right atrium rather than into the left atrium. The authors present one case of total anomalous pulmonary venous connection and two cases of partial anomalous pulmonary venous connection, one of supracardiac drainage into the brachiocephalic vein, and the other of infracardiac anomalous venous drainage (scimitar syndrome). Through the presentation of these cases, this article aims to review the main pulmonary venous developmental defects, highlighting the role of imaging techniques in the assessment of these anomalies. Copyright © 2016 Sociedade Portuguesa de Cardiologia. Publicado por Elsevier España, S.L.U. All rights reserved.

Aspirin in venous leg ulcer study (ASPiVLU): study protocol for a randomised controlled trial.

PubMed

Weller, Carolina D; Barker, Anna; Darby, Ian; Haines, Terrence; Underwood, Martin; Ward, Stephanie; Aldons, Pat; Dapiran, Elizabeth; Madan, Jason J; Loveland, Paula; Sinha, Sankar; Vicaretti, Mauro; Wolfe, Rory; Woodward, Michael; McNeil, John

2016-04-11

Venous leg ulceration is a common and costly problem that is expected to worsen as the population ages. Current treatment is compression therapy; however, up to 50 % of ulcers remain unhealed after 2 years, and ulcer recurrence is common. New treatments are needed to address those wounds that are more challenging to heal. Targeting the inflammatory processes present in venous ulcers is a possible strategy. Limited evidence suggests that a daily dose of aspirin may be an effective adjunct to aid ulcer healing and reduce recurrence. The Aspirin in Venous Leg Ulcer study (ASPiVLU) will investigate whether 300-mg oral doses of aspirin improve time to healing. This randomised, double-blinded, multicentre, placebo-controlled, clinical trial will recruit participants with venous leg ulcers from community settings and hospital outpatient wound clinics across Australia. Two hundred sixty-eight participants with venous leg ulcers will be randomised to receive either aspirin or placebo, in addition to compression therapy, for 24 weeks. The primary outcome is time to healing within 12 weeks. Secondary outcomes are ulcer recurrence, wound pain, quality of life and wellbeing, adherence to study medication, adherence to compression therapy, serum inflammatory markers, hospitalisations, and adverse events at 24 weeks. The ASPiVLU trial will investigate the efficacy and safety of aspirin as an adjunct to compression therapy to treat venous leg ulcers. Study completion is anticipated to occur in December 2018. Australian New Zealand Clinical Trials Registry, ACTRN12614000293662.

Neuromuscular dentistry: Occlusal diseases and posture

PubMed Central

Khan, Mohd Toseef; Verma, Sanjeev Kumar; Maheshwari, Sandhya; Zahid, Syed Naved; Chaudhary, Prabhat K.

2013-01-01

Neuromuscular dentistry has been a controversial topic in the field of dentistry and still remains debatable. The issue of good occlusion and sound health has been repeatedly discussed. Sometimes we get complains of sensitive teeth and sometimes of tired facial muscles on getting up in the morning. Owing to the intimate relation of masticatory apparatus with the cranium and cervico-scapular muscular system, the disorders in any system, draw attention from concerned clinicians involved in management, to develop an integrated treatment protocol for the suffering patients. There may be patients reporting to the dental clinics after an occlusal restoration or extraction, having pain in or around the temporomandibular joint, headache or neck pain. Although their esthetic demands must not be undermined during the course of treatment plan, whenever dental treatment of any sort is planned, occlusion/bite should be given prime importance. Very few dentist are able to diagnose the occlusal disease and of those who diagnose many people resort to aggressive treatment modalities. This paper aims to report the signs of occlusal disease, and discuss their association with TMDs and posture. PMID:25737904

Venous thromboembolism: a UK perspective.

PubMed

Kakkar, Ajay

2009-07-01

Venous thromboembolism remains a significant cause of morbidity and mortality in the UK, and its dangers, particularly in hospitalized patients, have long been recognized. Recent measures to tackle this problem and new treatments should alleviate the burden of venous thromboembolism for patients, their families and hospital services.

Venous thromboembolism and arterial complications.

PubMed

Prandoni, Paolo; Piovella, Chiara; Pesavento, Raffaele

2012-04-01

An increasing body of evidence suggests the likelihood of a link between venous and arterial thrombosis. The two vascular complications share several risk factors, such as age, obesity, smoking, diabetes mellitus, blood hypertension, hypertriglyceridemia, and metabolic syndrome. Moreover, there are many examples of conditions accounting for both venous and arterial thrombosis, such as the antiphospholipid antibody syndrome, hyperhomocysteinemia, malignancies, infections, and the use of hormonal treatment. Finally, several recent studies have consistently shown that patients with venous thromboembolism are at a higher risk of arterial thrombotic complications than matched control individuals. We, therefore, speculate the two vascular complications are simultaneously triggered by biological stimuli responsible for activating coagulation and inflammatory pathways in both the arterial and the venous system. Future studies are needed to clarify the nature of this association, to assess its extent, and to evaluate its implications for clinical practice. Thieme Medical Publishers 333 Seventh Avenue, New York, NY 10001, USA.

Venous leakage treatment revisited: pelvic venoablation using aethoxysclerol under air block technique and Valsalva maneuver.

PubMed

Herwig, Ralf; Sansalone, Salvatore

2015-03-31

We evaluated the effectiveness of pelvic vein embolization with aethoxysclerol in aero-block technique for the treatment of impotence due to venous leakage in men using sildenafil for intercourse. The aim of the procedure was to reduce the use of sildenafil. A total of 96 patients with veno-occlusive dysfunction, severe enough for the need of PDE5 inhibitors for vaginal penetration, underwent pelvic venoablation with aethoxysclerol. The mean patient age was 53.5 years. Venous leaks were identified by Color Doppler Ultrasound after intracavernous alprostadil injection. Under local anesthesia a 20-gauge needle was inserted into the deep dorsal penile vein. The pelvic venogram was obtained through deep dorsal venography. Aethoxysclerol 3% as sclerosing agent was injected after air-block under Valsalva manoeuver. Success was defined as the ability to achieve vaginal insertion without the aid of any drugs, vasoactive injections, penile prosthesis, or vacuum device. Additionally, a pre- and post- therapy IIEF score and a digital overnight spontaneous erections protocol (OSEP) with the NEVA™-system was performed. At 3 month follow-up 77 out of 96 patients (80.21%) reported to have erections sufficient for vaginal insertion without the use of any drug or additional device. Four (4.17%) patients did not report any improvement. Follow up with color Doppler ultrasound revealed a new or persistent venous leakage in 8 (8.33%) of the patients. No serious complications occurred. Our new pelvic venoablation technique using aethoxysclerol in air-block technique was effective, minimally invasive, and cost-effective. All patients were able to perform sexual intercourse without the previously used dosage of PDE5 inhibitor. This new method may help in patients with contra-indications against PDE5 inhibitors, in patients who cannot afford the frequent usage of expensive oral medication or those who do not fully respond to PDE5-inhibitors.

Risk factors for upper extremity venous thrombosis associated with peripherally inserted central venous catheters.

PubMed

Marnejon, Thomas; Angelo, Debra; Abu Abdou, Ahmed; Gemmel, David

2012-01-01

To identify clinically important risk factors associated with upper extremity venous thrombosis following peripherally inserted central venous catheters (PICC). A retrospective case control study of 400 consecutive patients with and without upper extremity venous thrombosis post-PICC insertion was performed. Patient data included demographics, body mass index (BMI), ethnicity, site of insertion, size and lumen of catheter, internal length, infusate, and co-morbidities, such as diabetes mellitus, congestive heart failure, and renal failure. Additional risk factors analyzed were active cancer, any history of cancer, recent trauma, smoking, a history of prior deep vein thrombosis, and recent surgery, defined as surgery within three months prior to PICC insertion. The prevalence of trauma, renal failure, and infusion with antibiotics and total parenteral nutrition (TPN) was higher among patients exhibiting upper extremity venous thrombosis (UEVT), when compared to controls. Patients developing UEVT were also more likely to have PICC line placement in a basilic vein and less likely to have brachial vein placement (P<.001). Left-sided PICC line sites also posed a greater risk (P=.026). The rate of standard DVT prophylaxis with low molecular weight heparin and unfractionated heparin and the use of warfarin was similar in both groups. Average length of hospital stay was almost double among patients developing UEVT, 19.5 days, when compared to patients undergoing PICC line insertion without thrombosis, 10.8 days (t=6.98, P<.001). In multivariate analysis, trauma, renal failure, left-sided catheters, basilic placement, TPN, and infusion with antibiotics, specifically vancomycin, were significant risk factors for UEVT associated with PICC insertion. Prophylaxis with low molecular weight heparin, unfractionated heparin or use of warfarin did not prevent the development of venous thrombosis in patients with PICCs. Length of hospital stay and cost are markedly increased in

Venous trauma in the Lebanon War--2006.

PubMed

Nitecki, Samy S; Karram, Tony; Hoffman, Aaron; Bass, Arie

2007-10-01

Reports on venous trauma are relatively sparse. Severe venous trauma is manifested by hemorrhage, not ischemia. Bleeding may be internal or external and rarely may lead to hypovolemic shock. Repair of major extremity veins has been a subject of controversy and the current teaching is to avoid venous repair in an unstable or multi-trauma patient. The aim of the current paper is to present our recent experience in major venous trauma during the Lebanon conflict, means of diagnosis and treatment in a level I trauma center. All cases of major venous trauma, either isolated or combined with arterial injury, admitted to the emergency room during the 33-day conflict were reviewed. Out of 511 wounded soldiers and civilians who were admitted to our service over this period, 12 (2.3%) sustained a penetrating venous injury either isolated (5) or combined with arterial injury (7). All injuries were secondary to high velocity penetrating missiles or from multiple pellets stored in long-range missiles. All injuries were accompanied by additional insult to soft tissue, bone and viscera. The mean injury severity score was 15. Severe external bleeding was the presenting symptom in three cases of isolated venous injury (jugular, popliteal and femoral). The diagnosis of a major venous injury was made by a CTA scan in five cases, angiography in one and during surgical exploration in six cases. All injured veins were repaired: three by venous interposition grafts, four by end to end anastomosis, three by lateral suture and two by endovascular techniques. None of the injuries was treated by ligation of a major named vein. Immediate postoperative course was uneventful in all patients and the 30-day follow-up (by clinical assessment and duplex scan) has demonstrated a patent repair with no evidence of thrombosis. Without contradicting the wisdom of ligating major veins in the setup of multi-trauma or an unstable patient, our experience indicates that a routine repair of venous trauma can

Increased release of norepinephrine and dopamine from canine kidney during bilateral carotid occlusion

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

Bradley, T.; Hjemdahl, P.; DiBona, G.F.

1987-02-01

The renal overflow of norepinephrine (NE) and dopamine (DA) to plasma from the innervated kidney was studied at rest and during sympathetic nervous system activation by bilateral carotid artery occlusion (BCO) in vagotomized dogs under barbiturate or barbiturate/nitrous oxide anesthesia. BCO elevated arterial pressure and the arterial plasma concentration of NE, DA, and epinephrine (Epi). Renal vascular resistance (renal arterial pressure kept constant) increased by 15 +/- 7% and the net renal venous outflows (renal veno-arterial concentration difference x renal plasma flow) of NE and DA were enhanced. To obtain more correct estimates of the renal contribution to the renalmore » venous catecholamine outflow, they corrected for the renal extraction of arterial catecholamines, assessed as the extractions of (/sup 3/H)NE, (/sup 3/H)DA, or endogenous Epi. The (/sup 3/H)NE corrected renal NE overflow to plasma increased from 144 +/- 40 to 243 +/- 64 pmol-min/sup -1/ during BCO, which, when compared with a previous study of the (/sup 3/H)NE corrected renal NE overflow to plasma evoked by electrical renal nerve stimulation, corresponds to a 40% increase in nerve impulse frequency from approx. 0.6 Hz. If the renal catecholamine extraction was not taken into account the effect of BCO was underestimated. The renal DA overflow to plasma was about one-fifth of the NE overflow both at rest and during BCO, indicating that there was no preferential activation of noradrenergic or putative dopaminergic nerves by BCO.« less

Percutaneous transfemoral repositioning of malpositioned central venous catheters.

PubMed

Hartnell, G G; Roizental, M

1995-04-01

Central venous catheters inserted by blind surgical placement may not advance into a satisfactory position and may require repositioning. Malpositioning via surgical insertion is common in patients in whom central venous catheters have previously been placed, as these patients are more likely to have central venous thrombosis and distortion of central venous anatomy. This is less of a problem when catheter placement is guided by imaging; however, even when insertion is satisfactory, central venous catheters may become displaced spontaneously after insertion (Fig. 1). Repositioning can be effected by direct manipulation using guidewires or tip-deflecting wires [1, 2], by manipulation via a transfemoral venous approach [3-5], and by injection of contrast material or saline [6]. Limitations of the direct approach include (1) the number and type of maneuvers that can be performed to effect repositioning when anatomy is distorted, (2) difficulty in accessing the catheter, and (3) the risk of introducing infection. Moreover, these patients are often immunosuppressed, and there is a risk of introducing infection by exposing and directly manipulating the venous catheter. Vigorous injection of contrast material or saline may be unsuccessful for the same reasons: It seldom exerts sufficient force to reposition large-caliber central venous catheters and may cause vessel damage or rupture if injection is made into a small or thrombosed vessel. We illustrate several alternative methods for catheter repositioning via a transfemoral venous approach.

The Diagnostic Value of 3-Dimensional Sampling Perfection With Application Optimized Contrasts Using Different Flip Angle Evolutions (SPACE) MRI in Evaluating Lower Extremity Deep Venous Thrombus.

PubMed

Wu, Gang; Xie, Ruyi; Zhang, Xiaoli; Morelli, John; Yan, Xu; Zhu, Xiaolei; Li, Xiaoming

2017-12-01

The aim of this study was to evaluate the diagnostic performance of noncontrast magnetic resonance imaging utilizing sampling perfection with application optimized contrasts using different flip angle evolutions (SPACE) in detecting deep venous thrombus (DVT) of the lower extremity and evaluating clot burden. This prospective study was approved by the institutional review board. Ninety-four consecutive patients (42 men, 52 women; age range, 14-87 years; average age, 52.7 years) suspected of lower extremity DVT underwent ultrasound (US) and SPACE. The venous visualization score for SPACE was determined by 2 radiologists independently according to a 4-point scale (1-4, poor to excellent). The sensitivity and specificity of SPACE in detecting DVT were calculated based on segment, limb, and patient, with US serving as the reference standard. The clot burden for each segment was scored (0-3, patent to entire segment occlusion). The clot burden score obtained with SPACE was compared with US using a Wilcoxon test based on region, limb, and patient. Interobserver agreement in assessing DVT (absent, nonocclusive, or occlusive) with SPACE was determined by calculating Cohen kappa coefficients. The mean venous visualization score for SPACE was 3.82 ± 0.50 for reader 1 and 3.81 ± 0.50 for reader 2. For reader 1, sensitivity/specificity values of SPACE in detecting DVT were 96.53%/99.90% (segment), 95.24%/99.04% (limb), and 95.89%/95.24% (patient). For reader 2, corresponding values were 97.20%/99.90%, 96.39%/99.05%, and 97.22%/95.45%. The clot burden assessed with SPACE was not significantly different from US (P > 0.05 for region, limb, patient). Interobserver agreement of SPACE in assessing thrombosis was excellent (kappa = 0.894 ± 0.014). Non-contrast-enhanced 3-dimensional SPACE magnetic resonance imaging is highly accurate in detecting lower extremity DVT and reliable in the evaluation of clot burden. SPACE could serve as an important alternative for patients in whom US

Surgical management of venous malformations.

PubMed

Loose, D A

2007-01-01

Among vascular malformations, the predominantly venous malformations represent the majority of cases. They form a clinical entity and therefore need clear concepts concerning diagnosis and treatment. This paper presents an overview of contemporary classification as well as tactics and techniques of treatment. According to the Hamburg Classification, predominantly venous malformations are categorized into truncular and extratruncular forms, with truncular forms distinguished as obstructions and dilations, and extratruncular forms as limited or infiltrating. The tactics of treatment represent surgical and non-surgical methods or combined techniques. Surgical approaches utilize different tactics and techniques that are adopted based on the pathologic form and type of the malformation: (I) operation to reduce the haemodynamic activity of the malformation; (II) operation to eliminate the malformation; and (III) reconstructive operation. As for (I), a type of a tactic is the operation to derive the venous flow. In (II), the total or partial removal of the venous malformation is demonstrated subdivided into three different techniques. In this way, the infiltrating as well as the limited forms can be treated. An additional technique is dedicated to the treatment of a marginal vein. Approach (III) involves the treatment of venous aneurysms, where a variety of techniques have been successful. Long-term follow-up demonstrates positive results in 91% of the cases. Congenital predominantly venous malformations should be treated according to the principles developed during the past decades in vascular surgery, interventional treatment and multidisciplinary treatment. The days of predominantly conservative treatment should be relegated to the past. Special skills and experiences are necessary to carry out appropriate surgical strategy, and the required operative techniques should be dictated by the location and type of malformation and associated findings.

Vascular occlusion with a balloon-expandable stent occluder.

PubMed

Moss, J G; Laborde, J C; Clem, M C; Rivera, F J; Encarnacion, C E; Meyer, K B; Palmaz, J C

1994-05-01

To evaluate the effectiveness of a new vascular occlusion device. The device was created by coating a balloon-expandable stent with a silicone sleeve that tapers to a blind-ended nozzle at its leading end. Once crimp-mounted on an angioplasty balloon catheter, the device is introduced over a guide wire through a small end hole in the nozzle. The device was tested for stability and occlusive ability. No migration was measured over a pulsatile pulse range of 50-300 mm Hg, and mean flow rate in the occluded vessel was reduced from 443 mL/min +/- 99 (standard deviation) to 1.9 mL/min +/- 2.7. Subsequently, 12 arteries were occluded in three dogs, and immediate vascular occlusion was achieved in all vessels. An arteriovenous fistula was created in another six dogs and was successfully occluded with the device. Follow-up arteriography at 3 months demonstrated persistent occlusion with no migration of the device. This new occlusive device offers immediate vascular occlusion with excellent stability.

Occlusal considerations in implant therapy: clinical guidelines with biomechanical rationale.

PubMed

Kim, Yongsik; Oh, Tae-Ju; Misch, Carl E; Wang, Hom-Lay

2005-02-01

Due to lack of the periodontal ligament, osseointegrated implants, unlike natural teeth, react biomechanically in a different fashion to occlusal force. It is therefore believed that dental implants may be more prone to occlusal overloading, which is often regarded as one of the potential causes for peri-implant bone loss and failure of the implant/implant prosthesis. Overloading factors that may negatively influence on implant longevity include large cantilevers, parafunctions, improper occlusal designs, and premature contacts. Hence, it is important to control implant occlusion within physiologic limit and thus provide optimal implant load to ensure a long-term implant success. The purposes of this paper are to discuss the importance of implant occlusion for implant longevity and to provide clinical guidelines of optimal implant occlusion and possible solutions managing complications related to implant occlusion. It must be emphasized that currently there is no evidence-based, implant-specific concept of occlusion. Future studies in this area are needed to clarify the relationship between occlusion and implant success.

Cannulation for veno-venous extracorporeal membrane oxygenation

PubMed Central

2018-01-01

Extracorporeal membrane oxygenation (ECMO) is described as a modified, smaller cardiopulmonary bypass circuit. The veno-venous (VV) ECMO circuit drains venous blood, oxygenate the blood, and pump the blood back into the same venous compartment. Draining and reinfusing in the same compartment means there are a risk of recirculation. The draining position within the venous system, ECMO pump flow, return flow position within the venous system and the patients cardiac output (CO) all have an impact on recirculation. Using two single lumen cannulas or one dual lumen cannula, but also the design of the venous cannula, can have an impact on where within the venous system the cannula is draining blood and will affect the efficiency of the ECMO circuit. VV ECMO can be performed with different cannulation strategies. The use of two single lumen cannulas draining in inferior vena cava (IVC) and reinfusing in superior vena cava (SVC) or draining in SVC and reinfusing in IVC, or one dual lumen cannula inserted in right jugular vein is all possible cannulation strategies. Independent of cannulation strategy there will be a risk of recirculation. Efficiency can be reasonable in either strategy if the cannulas are carefully positioned and monitored during the dynamic procedure of pulmonary disease. The disadvantage draining from IVC only occurs when there is a need for converting from VV to veno-arterial (VA) ECMO, reinfusing in the femoral artery. Then draining from SVC is the most efficient strategy, draining low saturated venous blood, and also means low risk of dual circulation. PMID:29732177

A spontaneous pre-anastomotic occlusion does not necessarily impair forearm native dialysis fistulas: echo-Doppler, 3D MR angiographic and digital subtraction angiographic imaging.

PubMed

Verbeeck, N; Pillet, J C; Prospert, E; McLntyre, D; Lamy, S

2013-01-01

Renal transplantation is the choice treatment of end-stage renal disease. When it is not indicated or not immediately feasible, hemodialysis must be performed, preferably via a native arteriovenous fistula in the forearm. A pre-anastomotic occlusion of this type of fistula is often accompanied by a thrombosis of its draining vein. In some instances, the venous segment may remain permeable thanks to the development of arterial collateral pathways and may even allow efficient dialysis without any clinical syndrome of distal steal. We present the echo-Doppler, magnetic and angiographic characteristics of three of these collateralized shunts that have remained functional, in one of the cases following a percutaneous dilation.

Mid-Term Outcomes of Endovascular Treatment for TASC-II D Femoropopliteal Occlusive Disease with Critical Limb Ischemia

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

Torres-Blanco, Álvaro, E-mail: atorres658@yahoo.es; Edo-Fleta, Gemma; Gómez-Palonés, Francisco

2016-03-15

PurposeThe purpose of the study was to assess the safety and midterm effectiveness of endovascular treatment in Trans-Atlantic Inter-Society Consensus II (TASC-II) D femoropopliteal occlusions in patients with critical limb ischemia (CLI).MethodsPatients with CLI who underwent endovascular treatment for TASC-D de novo femoropopliteal occlusive disease between September 2008 and December 2013 were selected. Data included anatomic features, pre- and postprocedure ankle-brachial index, duplex ultrasound, and periprocedural complications. Sustained clinical improvement, limb salvage rate, freedom from target lesion revascularization (TLR), and freedom from target extremity revascularization (TER) were assessed by Kaplan–Meier estimation and predictors of restenosis/occlusion with Cox analysis.ResultsThirty-two patients underwentmore » treatment of 35 TASC-D occlusions. Mean age was 76 ± 9. Mean lesion length was 23 ± 5 cm. Twenty-eight limbs (80 %) presented tissue loss. Seventeen limbs underwent treatment by stent, 13 by stent-graft, and 5 by angioplasty. Mean follow-up was 29 ± 20 months. Seven patients required major amputation and six patients died during follow-up. Eighteen endovascular and three surgical TLR procedures were performed due to restenosis or occlusion. Estimated freedom from TLR and TER rates at 2 years were 41 and 76 %, whereas estimated primary and secondary patency rates were 41 and 79 %, respectively.ConclusionsEndovascular treatment for TASC II D lesions is safe and offers satisfying outcomes. This patient subset would benefit from a minimally invasive approach. Follow-up is advisable due to a high rate of restenosis. Further follow-up is necessary to know the long-term efficacy of these procedures.« less

Occlusion issues in early Renaissance art

PubMed Central

Gillam, Barbara

2011-01-01

Early Renaissance painters innovatively attempted to depict realistic three-dimensional scenes. A major problem was to produce the impression of overlap for surfaces that occlude one another in the scene but are adjoined in the picture plane. Much has been written about perspective in art but little about occlusion. Here I examine some of the strategies for depicting occlusion used by early Renaissance painters in relation to ecological considerations and perceptual research. Perceived surface overlap is often achieved by implementing the principle that an occluding surface occludes anything behind it, so that occlusion perception is enhanced by a lack of relationship of occluding contour to occluded contours. Some well-known figure-ground principles are also commonly used to stratify adjoined figures. Global factors that assist this stratification include the placement of figures on a ground plane, a high viewpoint, and figure grouping. Artists of this period seem to have differed on whether to occlude faces and heads, often carefully avoiding doing so. Halos were either eliminated selectively or placed oddly to avoid such occlusions. Finally, I argue that the marked intransitivity in occlusion by architecture in the paintings of Duccio can be related to the issue of perceptual versus cognitive influences on the visual impact of paintings. PMID:23145262

Characterization of central venous catheter-associated deep venous thrombosis in infants.

PubMed

Gray, Brian W; Gonzalez, Raquel; Warrier, Kavita S; Stephens, Lauren A; Drongowski, Robert A; Pipe, Steven W; Mychaliska, George B

2012-06-01

Deep venous thrombosis (DVT) is a frequent complication in infants with central venous catheters (CVCs). We performed this study to identify risk factors and risk-reduction strategies of CVC-associated DVT in infants. Infants younger than 1 year who had a CVC placed at our center from 2005 to 2009 were reviewed. Patients with ultrasonically diagnosed DVT were compared to those without radiographic evidence. Of 333 patients, 47% (155/333) had femoral, 33% (111/333) had jugular, and 19% (64/333) had subclavian CVCs. Deep venous thromboses occurred in 18% (60/333) of patients. Sixty percent (36/60) of DVTs were in femoral veins. Femoral CVCs were associated with greater DVT rates (27%; 42/155) than jugular (11%; 12/111) or subclavian CVCs (9%; 6/64; P < .01). There was a 16% DVT rate in those with saphenofemoral Broviac CVCs vs 83% (20/24) in those with percutaneous femoral lines (P < .01). Multilumen CVCs had higher DVT rates than did single-lumen CVCs (54% vs 6%, P < .01), and mean catheter days before DVT diagnosis was shorter for percutaneous lines than Broviacs (13 ± 17 days vs 30 ± 37 days, P = .02). Patients with +DVT had longer length of stay (86 ± 88 days vs 48 ± 48 days, P < .01) and higher percentage of intensive care unit admission (82% vs 70%, P = .02). Deep venous thrombosis reduction strategies in infants with CVCs include avoiding percutaneous femoral and multilumen CVCs, screening percutaneous lines, and early catheter removal. Copyright © 2012 Elsevier Inc. All rights reserved.

The possibility for use of venous flaps in plastic surgery

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

Baytinger, V. F., E-mail: baitinger@mail.tomsknet.ru; Kurochkina, O. S., E-mail: kurochkinaos@yandex.ru; Selianinov, K. V.

2015-11-17

The use of venous flaps is controversial. The mechanism of perfusion of venous flaps is still not fully understood. The research was conducted on 56 white rats. In our experimental work we studied two different models of venous flaps: pedicled venous flap (PVF) and pedicled arterialized venous flap (PAVF). Our results showed that postoperative congestion was present in all flaps. However 66.7% of all pedicled venous flaps and 100% of all pedicled arterialized venous flaps eventually survived. Histological examination revealed that postoperatively the blood flow in the skin of the pedicled arterialized venous flap became «re-reversed» again; there were nomore » differences between mechanism of survival of venous flaps and other flaps. On the 7-14th day in the skin of all flaps were processes of neoangiogenesis and proliferation. Hence the best scenario for the clinical use of venous flaps unfolds when both revascularization and skin coverage are required.« less

An evaluation of efficacy of balloon inflation on venous cannulation pain in children: a prospective, randomized, controlled study.

PubMed

Gupta, Devendra; Agarwal, Anil; Dhiraaj, Sanjay; Tandon, Manish; Kumar, Mukesh; Singh, Ravi Shankar; Singh, Prabhat K; Singh, Uttam

2006-05-01

Venipuncture is the most common painful event for a hospitalized child. We evaluated the efficacy of balloon inflation for attenuating venipuncture pain in children. Seventy-five pediatric patients aged 6-12 yr, ASA physical status I-II, of either sex, undergoing elective surgery were included in this prospective and randomized study. Patients were randomly divided into 3 equal groups of 25 each; Group I (control), Group II (distraction) pressed a rubber ball, and Group III (balloon) inflated a balloon. A manual venous occlusion was applied on the forearm and venipuncture was performed with a 22-gauge venous cannula. Pain was self-reported by a pain face scale with a 10-cm visual analog scale (VAS) placed at its back, where 0 = "no pain" and 10 = "worst imaginable pain." VAS scores of 1-3 were rated as mild, 4-6 as moderate, and >6 as severe. Median (interquartile range) VAS score in the balloon group was 1 (3), which was reduced as compared with 2 (2) and 4 (2) observed in the distraction and control groups, respectively (P < 0.000). Significant reduction in the incidence and severity of venipuncture pain was also observed in the balloon group compared with the other 2 groups (P < 0.05).

Normal venous anatomy and physiology of the lower extremity.

PubMed

Notowitz, L B

1993-06-01

Venous disease of the lower extremities is common but is often misunderstood. It seems that the focus is on the exciting world of arterial anatomy and pathology, while the topic of venous anatomy and pathology comes in second place. However, venous diseases such as chronic venous insufficiency, leg ulcers, and varicose veins affect much of the population and may lead to disability and death. Nurses are often required to answer complex questions from the patients and his or her family about the patient's disease. Patients depend on nurses to provide accurate information in terms they can understand. Therefore it is important to have an understanding of the normal venous system of the legs before one can understand the complexities of venous diseases and treatments. This presents an overview of normal venous anatomy and physiology.

Time to aortic occlusion: It's all about access.

PubMed

Romagnoli, Anna; Teeter, William; Pasley, Jason; Hu, Peter; Hoehn, Melanie; Stein, Deborah; Scalea, Thomas; Brenner, Megan

2017-12-01

Resuscitative endovascular balloon occlusion of the aorta (REBOA) is a less invasive method of proximal aortic occlusion compared with resuscitative thoracotomy with aortic cross-clamping (RTACC). This study compared time to aortic occlusion with REBOA and RTACC, both including and excluding time required for common femoral artery (CFA) cannulation. This was a retrospective, single-institution review of REBOA or RTACC performed between February 2013 and January 2016. Time of skin incision to aortic cross-clamp for RTACC, time required for CFA cannulation by percutaneous and open methods, and time from guide-wire insertion to balloon inflation at Zone 1 for REBOA, were obtained from videographic recordings. Eighteen RTACC and 21 REBOAs were performed. Median (Q1, Q3) time from skin incision to aortic cross-clamping was 317 seconds (227, 551 seconds). Median (Q1, Q3) time from start of arterial access to Zone 1 balloon occlusion was 474 seconds (431, 572 seconds) (vs. RTACC, p = 0.01). All REBOA procedures were performed with the same device. The median time to complete CFA cannulation was 247 seconds (range, 164-343 seconds), with no difference between percutaneous or open procedures (p = 0.07). The median (Q1, Q3) time to aortic occlusion in REBOA once arterial access had been established was 245 seconds (179, 295.5 seconds), which was significantly shorter than RTACC (p = 0.003). Once CFA access is achieved, time to aortic occlusion is faster with REBOA. Time to aortic occlusion is less than the time required to cannulate the CFA either by percutaneous or open approaches, emphasizing the importance of accurate and expedient CFA access. Resuscitative endovascular balloon occlusion of the aorta may represent a feasible alternative to thoracotomy for aortic occlusion. Time to aortic occlusion will likely decrease with the advent of newer REBOA technology. The rate-limiting portion of REBOA continues to be obtaining CFA access. Therapeutic, level V.

Predictors of early stent occlusion among plastic biliary stents.

PubMed

Khashab, Mouen A; Kim, Katherine; Hutfless, Susan; Lennon, Anne Marie; Kalloo, Anthony N; Singh, Vikesh K

2012-09-01

A major disadvantage of plastic biliary stents is their short patency rates. The aim of this study was to identify predictors of early stent occlusion among patients receiving conventional plastic biliary stents. Early stent occlusion was defined as worsening cholestatic liver test results of a severity sufficiently significant to warrant ERCP with stent exchange prior to the planned stent exchange, or as symptoms of cholangitis. The association of cumulative stent diameter, demographics, stricture location, procedure indication, Charlson comorbidity index, history of prior early stent occlusion, presence of gallbladder, and performance of sphincteromy with the occurrence of early stent occlusion was studied using logistic regression and multivariate analysis. Our patient cohort comprised 343 patients (mean age 59.3 years) who underwent 561 ERCP procedures with the placement of one or more plastic biliary stents (mean number of stents per procedure 1.2, mean total diameter of stents per procedure 12 Fr). Early stent occlusion occurred in 73 (13 %) procedures. Female gender was protective against early stent occlusion (adjusted OR 0.54, 95 % CI 0.32-0.90, p = 0.02), while hilar stricture location was independently associated with a significantly increased risk of early stent occlusion (adjusted OR 3.41, 95 % CI 1.68-6.90, p = 0.0007). Early occlusion of conventional biliary stents occurred in 13 % of cases. While female gender decreased the risk of early stent occlusion, hilar stricture location was a significant predictor of early stent occlusion. Our results suggest that physicians should consider early elective stent exchange in patients with hilar strictures.

Venous Shunt Versus Venous Ligation for Vascular Damage Control: The Immunohistochemical Evidence.

PubMed

Góes Junior, Adenauer Marinho de Oliveira; Abib, Simone de Campos Vieira; Alves, Maria Teresa de Seixas; Ferreira, Paulo Sérgio Venerando da Silva; Andrade, Mariseth Carvalho de

2017-05-01

To evaluate the expression of immunohistochemical markers of tissue ischemia (iNOS, eNOS, and HSP70) in a vascular damage control experimental model to determine if a venous temporary vascular shunt insertion leads to a better limb perfusion when compared with the ligature of the injured vein. Experimental study in male Sus Scrofa weighting 40 Kg. Animals were distributed into 5 groups: group 1 animals were submitted to right external iliac artery (EIA) shunting and right external iliac vein (EIV) ligation; group 2 animals were submitted to right EIA shunting and right EIV shunting; group 3 animals were submitted to right EIV ligation; group 4 animals were submitted to right EIV shunting; group 5 animals were not submitted to vascular shunting or venous ligation. Transonic Systems flowmeters were used to measure vascular flow on right and left external iliac vessels, and i-STAT (Abbot) portable blood analyzer was used for EIVs blood biochemical analysis. An initial baseline register of invasive arterial pressure, iliac vessels flow, and venous blood analysis was performed. Arterial pressure and iliac vessels flow were taken immediately after right iliac vessels shunting or ligation. Then, hemorrhagic shock was induced by continuous 20 mL/min blood withdraw from the external right jugular vein whereas arterial blood pressure and iliac vessels flow registers were taken every 10 min, and blood samples from EIVs were obtained every 30 min until the vascular flow through right EIA (or through the shunt inserted into the right EIV for group 4 animals) became inexistent or until the animal's death. After the end of the experiments, bilateral hind limb's biopsies were obtained for immunohistochemical analysis. Using image editing and analysis software, the expression of iNOS, eNOS, and HSP70 (3 well-known ischemic associated immunohistochemical markers) was assessed. The mean expression of each marker in the right hind limb was compared between groups. For statistical

Influence of denture adhesives on occlusion and disocclusion times.

PubMed

Abdelnabi, Mohamed Hussein; Swelem, Amal Ali; Al-Dharrab, Ayman A

2016-03-01

The effectiveness of adhesives in enhancing several functional aspects of complete denture performance has been well established. The direct influence of adhesives on occlusal contact simultaneity has not yet been investigated. The purpose of this crossover clinical trial was to evaluate quantitatively the influence of adhesives on occlusal balance by recording timed occlusal contacts; namely occlusion time (OT) and disocclusion time during right (DT-right) and left (DT-left) excursions by using computerized occlusal analysis. A crossover clinical trial was adopted. Assessments were carried out while participants (n=49) wore their dentures first without then with adhesives. Computerized occlusal analysis using the T-Scan III system was conducted to perform baseline computer-guided occlusal adjustment for conventionally fabricated dentures. Retention and stability assessment using the modified Kapur index and recording of OT and DT-right and DT-left values using the T-Scan III were subsequently carried out for all dentures, first without adhesives and then after application of adhesive. All T-Scan procedures were carried out by the same clinician. Wilcoxon signed-rank test was used to analyze the Kapur index scores and occlusal parameters (α=.05). Stability and retention of conventional dentures ranged initially from good to very good. However, adhesive application resulted in significant improvement (P<.001) in stability and retention and a significant decrease in duration of all occlusal parameters (OT [P=.003], DT-right [P=.003], and DT-left [P=.008]). Adhesives significantly decreased OT and DT durations in initially well-fitting complete dentures with fairly well balanced occlusion, and further enhanced denture stability and occlusal contact simultaneity. Copyright © 2016 Editorial Council for the Journal of Prosthetic Dentistry. Published by Elsevier Inc. All rights reserved.

Load-bearing capacity of various CAD/CAM monolithic molar crowns under recommended occlusal thickness and reduced occlusal thickness conditions

PubMed Central

Choi, Sulki

2017-01-01

PURPOSE The goal of this study was to evaluate the fracture resistances of various monolithic crowns fabricated by computer-aided design and computer-aided manufacturing (CAD/CAM) with different thickness. MATERIALS AND METHODS Test dies were fabricated as mandibular molar forms with occlusal reductions using CAD/CAM. With different occlusal thickness (1.0 or 1.5 mm), a polymer-infiltrated ceramic network (Enamic, EN), and zirconia-reinforced lithium silicate (Suprinity, SU and Celtra-Duo, CD) were used to fabricate molar crowns. Lithium disilicate (e.max CAD, EM) crowns (occlusal: 1.5 mm) were fabricated as control. Seventy crowns (n=10 per group) were bonded to abutments and stored in water for 24 hours. A universal testing machine was used to apply load to crown until fracture. The fractured specimens were examined with a scanning electron microscopy. RESULTS The type of ceramics and the occlusal thickness showed a significant interaction. With a recommended thickness (1.5 mm), the SU revealed the mean load similar to the EM, higher compared with those of the EN and CD. The fracture loads in a reduced thickness (1.0 mm) were similar among the SU, CD, and EN. The mean fracture load of the SU and CD enhanced significantly when the occlusal thickness increased, whereas that of the EN did not. CONCLUSION The fracture loads of monolithic crowns were differently influenced by the changes in occlusal thickness, depending on the type of ceramics. Within the limitations of this study, all the tested crowns withstood the physiological masticatory loads both at the recommended and reduced occlusal thickness. PMID:29279761

Research on target tracking algorithm based on spatio-temporal context

NASA Astrophysics Data System (ADS)

Li, Baiping; Xu, Sanmei; Kang, Hongjuan

2017-07-01

In this paper, a novel target tracking algorithm based on spatio-temporal context is proposed. During the tracking process, the camera shaking or occlusion may lead to the failure of tracking. The proposed algorithm can solve this problem effectively. The method use the spatio-temporal context algorithm as the main research object. We get the first frame's target region via mouse. Then the spatio-temporal context algorithm is used to get the tracking targets of the sequence of frames. During this process a similarity measure function based on perceptual hash algorithm is used to judge the tracking results. If tracking failed, reset the initial value of Mean Shift algorithm for the subsequent target tracking. Experiment results show that the proposed algorithm can achieve real-time and stable tracking when camera shaking or target occlusion.

Long-term Outcome of Peripherally Implanted Venous Access Ports in the Forearm in Female Cancer Patients

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

Klösges, Laura, E-mail: l.kloesges@uni-bonn.de; Meyer, Carsten, E-mail: carsten.meyer@ukb.uni-bonn.de; Boschewitz, Jack, E-mail: jack.boschewitz@ukb.uni-bonn.de

PurposeThe aim of this retrospective study was to analyze the long-term outcome of peripherally implanted venous access ports in the forearm at our institution in a female patient collective.MethodsBetween June 2002 and May 2011, a total of 293 female patients with an underlying malignancy had 299 forearm ports implanted in our interventional radiology suite. The mean age of the cohort was 55 ± 12 years (range 26–81 years). The majority of women suffered from breast (59.5 %) or ovarian cancer (28.1 %). Complications were classified as infectious complications, thrombotic and nonthrombotic catheter dysfunction (dislocation of the catheter or port chamber, fracture with/without embolization or kinking ofmore » the catheter, port occlusion), and others.ResultsWe analyzed a total of 90,276 catheter days in 248 port systems (47 patients were lost to follow-up). The mean device service interval was 364 days per catheter (range 8–2,132, median 223 days, CI 311–415, SD 404). Sixty-seven early (≤30 days from implantation) or late complications (>30 days) occurred during the observation period (0.74/1,000 catheter days). Common complications were port infection (0.18/1,000 days), thrombotic dysfunction (0.12/1,000 days), and skin dehiscence (0.12/1,000 days). Nonthrombotic dysfunction occurred in a total of 21 cases (0.23/1,000 days) and seemed to cumulate on the venous catheter entry site on the distal upper arm.ConclusionPeripherally implanted venous access ports in the forearm are a safe alternative to chest or upper-arm ports in female oncology patients. Special attention should be paid to signs of skin dehiscence and nonthrombotic dysfunction, especially when used for long-term treatment.« less

Post-thrombotic syndrome after central venous catheter removal in childhood cancer survivors: A prospective cohort study.

PubMed

Polen, E; Weintraub, M; Stoffer, C; Jaffe, D H; Burger, A; Revel-Vilk, S

2015-02-01

Although the use of central venous catheters (CVCs) has greatly improved the quality of care of children with cancer, these catheters increase the risk of deep vein thrombosis (DVT) and the potential long-term complication of post-thrombotic syndrome (PTS). We aimed to study PTS post-CVC removal using physical, functional and health related quality of life (HRQoL) domains in childhood cancer and bone marrow transplantation (BMT) survivors. We conducted a prospective study in a cohort of childhood cancer and BMT survivors post-CVC use. Participants were evaluated for PTS with the Modified Villalta Score (MVS) and the Manco-Johnson Instrument (MJI). HRQoL was assessed using the PedsQL™ questionnaire. A total of 158 children were enrolled at a median of 41 (4-149) months from CVC removal. Signs and symptoms of PTS were present in 34% (95% confidence interval [CI] 27-43%) (MVS criteria) and 30.5% (95% CI 23.1-37.8%) (MJI criteria). Diagnosis of PTS was associated with history of CVC occlusion, history of CVC-related DVT and the use of ≥2 CVCs. The presence of signs and symptoms of PTS was a predictor for low HRQoL tested by the PedsQL™ Total Scale scores and Physical Health Summary scores. PTS post-CVC removal in pediatric cancer survivors is not a rare event. The association between PTS and the history of CVC occlusion confirms earlier findings, and suggests that CVC occlusion may indicate asymptomatic DVT. PTS is also associated with lower HRQoL scores highlighting the need to study preventive measures, especially for high risk groups. Pediatr Blood Cancer 2015;62:285-290. © 2014 Wiley Periodicals, Inc. © 2014 Wiley Periodicals, Inc.

Eye movements and manual interception of ballistic trajectories: effects of law of motion perturbations and occlusions.

PubMed

Delle Monache, Sergio; Lacquaniti, Francesco; Bosco, Gianfranco

2015-02-01

Manual interceptions are known to depend critically on integration of visual feedback information and experience-based predictions of the interceptive event. Within this framework, coupling between gaze and limb movements might also contribute to the interceptive outcome, since eye movements afford acquisition of high-resolution visual information. We investigated this issue by analyzing subjects' head-fixed oculomotor behavior during manual interceptions. Subjects moved a mouse cursor to intercept computer-generated ballistic trajectories either congruent with Earth's gravity or perturbed with weightlessness (0 g) or hypergravity (2 g) effects. In separate sessions, trajectories were either fully visible or occluded before interception to enforce visual prediction. Subjects' oculomotor behavior was classified in terms of amounts of time they gazed at different visual targets and of overall number of saccades. Then, by way of multivariate analyses, we assessed the following: (1) whether eye movement patterns depended on targets' laws of motion and occlusions; and (2) whether interceptive performance was related to the oculomotor behavior. First, we found that eye movement patterns depended significantly on targets' laws of motion and occlusion, suggesting predictive mechanisms. Second, subjects coupled differently oculomotor and interceptive behavior depending on whether targets were visible or occluded. With visible targets, subjects made smaller interceptive errors if they gazed longer at the mouse cursor. Instead, with occluded targets, they achieved better performance by increasing the target's tracking accuracy and by avoiding gaze shifts near interception, suggesting that precise ocular tracking provided better trajectory predictions for the interceptive response.

Acute venous sinus thrombosis after chickenpox infection.

PubMed

Sardana, Vijay; Mittal, Lal Chand; Meena, S R; Sharma, Deepti; Khandelwal, Girish

2014-08-01

Chickenpox is one of the classic childhood diseases. Recently chicken pox has been reported in adults with more severe systemic and neurological complications. Cerebral venous thrombosis (CVT) is a life threatening disorder if not treated in time. We report a patient with post varicella CVT as a rare complication of primary Varicella zoster virus. Vasculitic arterial infarction is known while venous stroke has rarely been reported with Varicella-zoster virus infection. Here, we report an immunocompetent 30 yr old male who developed chickenpox after contact with his daughter two month back. He presented with acute neurological deficit, one week after onset of skin lesion. MR venography revealed non-visualisation of left transverse sinus and left sigmoid sinus suggestive of venous sinus thrombosis. Varicella infection is rarely associated with venous sinus thrombosis. Possibly hypercoagulable state produced by the infection or direct invasion of virus in venous endothelial wall with subsequent damage to endothelium leading to thrombosis could be the cause.

History of venous leg ulcers.

PubMed

Gianfaldoni, S; Wollina, U; Lotti, J; Gianfaldoni, R; Lotti, T; Fioranelli, M; Roccia, M G

To retrieve the history of venous ulcers and of skin lesions in general, we must go back to the appearance of human beings on earth. It is interesting to note that cutaneous injuries evolved parallel to human society. An essential first step in the pathogenesis of ulcers was represented by the transition of the quadruped man to Homo Erectus. This condition was characterized by a greater gravitational pressure on the lower limbs, with consequences on the peripheral venous system. Furthermore, human evolution was characterized by an increased risk of traumatic injuries, secondary to his natural need to create fire and hunt (e.g. stones, iron, fire, animal fighting). Humans then began to fight one another until they came to real wars, with increased frequency of wounds and infectious complications. The situation degraded with the introduction of horse riding, introduced by the Scites, who first tamed animals in the 7th century BC. This condition exhibited iliac veins at compression phenomena, favouring the venous stasis. With time, man continued to evolve until the modern age, which is characterized by increased risk factors for venous wounds such as poor physical activity and dietary errors (1, 2).

Volumetric ambient occlusion for real-time rendering and games.

PubMed

Szirmay-Kalos, L; Umenhoffer, T; Toth, B; Szecsi, L; Sbert, M

2010-01-01

This new algorithm, based on GPUs, can compute ambient occlusion to inexpensively approximate global-illumination effects in real-time systems and games. The first step in deriving this algorithm is to examine how ambient occlusion relates to the physically founded rendering equation. The correspondence stems from a fuzzy membership function that defines what constitutes nearby occlusions. The next step is to develop a method to calculate ambient occlusion in real time without precomputation. The algorithm is based on a novel interpretation of ambient occlusion that measures the relative volume of the visible part of the surface's tangent sphere. The new formula's integrand has low variation and thus can be estimated accurately with a few samples.

Varying face occlusion detection and iterative recovery for face recognition

NASA Astrophysics Data System (ADS)

Wang, Meng; Hu, Zhengping; Sun, Zhe; Zhao, Shuhuan; Sun, Mei

2017-05-01

In most sparse representation methods for face recognition (FR), occlusion problems were usually solved via removing the occlusion part of both query samples and training samples to perform the recognition process. This practice ignores the global feature of facial image and may lead to unsatisfactory results due to the limitation of local features. Considering the aforementioned drawback, we propose a method called varying occlusion detection and iterative recovery for FR. The main contributions of our method are as follows: (1) to detect an accurate occlusion area of facial images, an image processing and intersection-based clustering combination method is used for occlusion FR; (2) according to an accurate occlusion map, the new integrated facial images are recovered iteratively and put into a recognition process; and (3) the effectiveness on recognition accuracy of our method is verified by comparing it with three typical occlusion map detection methods. Experiments show that the proposed method has a highly accurate detection and recovery performance and that it outperforms several similar state-of-the-art methods against partial contiguous occlusion.

Percutaneous Treatment of Central Venous Stenosis in Hemodialysis Patients: Long-Term Outcomes

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

Kim, Young Chul; Won, Jong Yun, E-mail: jywon@yumc.yonsei.ac.kr; Choi, Sun Young

2009-03-15

The purpose of this study was to evaluate the long-term outcomes of endovascular treatment of central venous stenosis in patients with arteriovenous fistulas (AVFs) for hemodialysis. Five hundred sixty-three patients with AVFs who were referred for a fistulogram were enrolled in this study. Among them, 44 patients showed stenosis (n = 35) or occlusions (n = 9) in the central vein. For the initial treatment, 26 patients underwent percutaneous transluminal angioplasty (PTA) and 15 patients underwent stent placements. Periods between AVF formation and first intervention ranged from 3 to 144 months. Each patient was followed for 14 to 60 months.more » Procedures were successful in 41 of 44 patients (93.2%). Primary patency rates for PTA at 12 and 36 months were 52.1% and 20.0%, and assisted primary patency rates were 77.8% and 33.3%, respectively. Primary patency rates for stent at 12 and 36 months were 46.7% and 6.7%, and assisted primary patency rates were 60.0% and 20.0%, respectively. Fifteen of 26 patients with PTAs underwent repeated interventions because of restenosis. Fourteen of 15 patients with a stent underwent repeated interventions because of restenosis and combined migration (n = 1) and shortening (n = 6) of the first stent. There was no significant difference in patency between PTAs and stent placement (p > 0.05). Average AVF patency duration was 61.8 months and average number of endovascular treatments was 2.12. In conclusion, endovascular treatments of central venous stenosis could lengthen the available period of AVFs. There was no significant difference in patency between PTAs and stent placement.« less

Daily nursing care on patients undergoing venous-venous extracorporeal membrane oxygenation: a challenging procedure!

PubMed

Redaelli, Sara; Zanella, Alberto; Milan, Manuela; Isgrò, Stefano; Lucchini, Alberto; Pesenti, Antonio; Patroniti, Nicolò

2016-12-01

Daily nursing in critical care patients may alter vital parameters, especially in the most critically ill patients. The aim of our study was to evaluate feasibility and safety of daily nursing on patients undergoing venous-venous extracorporeal membrane oxygenation (vv-ECMO) for severe respiratory failure. Daily nursing was performed following defined phases (sponge bath, elevation with scooping stretcher, change position of endotracheal tube, dressing replacement). We recorded physiological and ECMO parameters before and during daily nursing in 5 patients for several days (total: 25 daily nursing) and adverse events: desaturation, hypertension, reduction of mixed venous oxygen saturation, arterial oxygen saturation or ECMO blood flow and elevation in minute ventilation. Sedative drug dosage and additional bolus were recorded. Daily nursing was performed in 92 % of cases (23/25), with a minimum of two adverse events per daily nursing. Hypertension and tachycardia were mostly recorded at the beginning, while desaturation, reduction in mixed venous oxygen saturation and blood flow were recorded during elevation with scooping stretcher. Increase in minute ventilation was frequent in spontaneous breathing patients. Additional bolus of sedation was required before and/or during nursing. Daily nursing significantly alters physiologic parameters; thus, it should be performed only when physicians are readily available to treat adverse events.

Impairment of Skin Capillary Recruitment Precedes Chronic Complications in Patients with Type 1 Diabetes

PubMed Central

Tibirica, Eduardo; Rodrigues, Elba; Cobas, Roberta; Gomes, Marilia B.

2007-01-01

Microvascular function in patients with type 1 diabetes without chronic complications was assessed using skin capillary recruitment during post-occlusive reactive hyperemia (PORH). Structural (maximal) capillary density was evaluated during venous occlusion. The study included 48 consecutive outpatients aged 26.3 ± 10.8 years with type 1 diabetes (duration of 9.5 years) without chronic complications and 34 control subjects. Intravital capillary video-microscopy was used in the dynamic study of skin capillaries in the dorsum of the fingers and toes. Capillary recruitment during PORH (% increase in mean capillary density, MCD) was significantly higher in the controls than the patients in both the fingers (p < 0.001) and toes (p < 0.001). During venous occlusion, MCD increase was also higher in the controls than the patients in both the fingers (p < 0.05) and toes (p < 0.0001). In patients, no difference was found between MCD at baseline and after venous occlusion in the fingers but a decrease was observed in the toes (p < 0.001). It is concluded that skin capillary function is significantly impaired in both fingers and toes of patients with type 1 diabetes without chronic complications. Moreover, capillary density during venous occlusion did not increase in either extremity in the patients, suggesting that their capillaries at rest are already maximally recruited. PMID:17823692

Dental cervical lesions associated with occlusal erosion and attrition.

PubMed

Khan, F; Young, W G; Shahabi, S; Daley, T J

1999-09-01

Acid demineralization of teeth causes occlusal erosion and attrition, and shallow and wedge-shaped cervical lesions putatively involving abfraction. From 250 patients with tooth wear, 122 with cervical lesions were identified. From epoxy resin replicas of their dentitions, associations of occlusal attrition or erosion or no wear with cervical lesions were recorded at 24 tooth sites (total 2928 sites). Criteria used to discriminate occlusal attrition from erosion, and shallow from grooved, wedge-shaped or restored cervical lesions were delineated by scanning electron microscopy. A 96 per cent association was found between occlusal and cervical pathology. Shallow cervical lesions were more commonly found in association with occlusal erosion. Wedge-shaped lesions were found equally commonly in association with occlusal erosion, as with attrition. Grooved and restored cervical lesions were uncommon. Differences were appreciated in the associations within incisor, canine, premolar and molar tooth sites which related more to the site-specificity of dental erosion than to attrition from occlusal forces. Non-carious lesions on teeth then have multifactorial aetiology and pathogenesis in which erosion and salivary protection play central roles. Dentists should primarily consider erosion in the diagnosis, prevention and treatment of tooth wear.

Current Status of the Application of Intracranial Venous Sinus Stenting

PubMed Central

Xu, Kan; Yu, Tiecheng; Yuan, Yongjie; Yu, Jinlu

2015-01-01

The intracranial venous sinus is an important component of vascular disease. Many diseases involve the venous sinus and are accompanied by venous sinus stenosis (VSS), which leads to increased venous pressure and high intracranial pressure. Recent research has focused on stenting as a treatment for VSS related to these diseases. However, a systematic understanding of venous sinus stenting (VS-Stenting) is lacking. Herein, the literature on idiopathic intracranial hypertension (IIH), venous pulsatile tinnitus, sinus thrombosis, high draining venous pressure in dural arteriovenous fistula (AVF) and arteriovenous malformation (AVM), and tumor-caused VSS was reviewed and analyzed to summarize experiences with VS-Stenting as a treatment. The literature review showed that satisfactory therapeutic effects can be achieved through stent angioplasty. Thus, the present study suggests that selective stent release in the venous sinus can effectively treat these diseases and provide new possibilities for treating intracranial vascular disease. PMID:26516306

[Venous thrombosis associated with central venous catheter use in patients with cancer].

PubMed

Iglesias Rey, Leticia; Fernández Pérez, Isaura; Barbagelata López, Cristina; Rivera Gallego, Alberto

2015-01-01

The use of central venous catheters for various applications (administration of chemotherapy, blood products and others) in patients with cancer is increasingly frequent. The association between thrombosis and catheter use has been fully established but aspects such as its causes, diagnosis, prophylaxis and treatment have not. We describe a case of thrombosis in a patient with cancer treated with chemotherapy who carried a central venous catheter. We also perform a review of the risk factors, the role of the prophylaxis and the treatment. Copyright © 2015 Elsevier España, S.L.U. All rights reserved.

Intracranial developmental venous anomaly: is it asymptomatic?

PubMed

Puente, A Bolívar; de Asís Bravo Rodríguez, F; Bravo Rey, I; Romero, E Roldán

2018-03-16

Intracranial developmental venous anomalies are the most common vascular malformation. In the immense majority of cases, these anomalies are asymptomatic and discovered incidentally, and they are considered benign. Very exceptionally, however, they can cause neurological symptoms. In this article, we present three cases of patients with developmental venous anomalies that presented with different symptoms owing to complications derived from altered venous drainage. These anomalies were located in the left insula, right temporal lobe, and cerebellum. The exceptionality of the cases presented as well as of the images associated, which show the mechanism through which the symptoms developed, lies in the low incidence of symptomatic developmental venous anomalies reported in the literature. Copyright © 2018 SERAM. Publicado por Elsevier España, S.L.U. All rights reserved.

Effects of isokinetic calf muscle exercise program on muscle strength and venous function in patients with chronic venous insufficiency.

PubMed

Ercan, Sabriye; Çetin, Cem; Yavuz, Turhan; Demir, Hilmi M; Atalay, Yurdagül B

2018-05-01

Objective The aim of this study was to observe the change of the ankle joint range of motion, the muscle strength values measured with an isokinetic dynamometer, pain scores, quality of life scale, and venous return time in chronic venous insufficiency diagnosed patients by prospective follow-up after 12-week exercise program including isokinetic exercises. Methods The patient group of this study comprised 27 patients (23 female, 4 male) who were diagnosed with chronic venous insufficiency. An exercise program including isokinetic exercise for the calf muscle was given to patients three days per week for 12 weeks. At the end of 12 weeks, five of the patients left the study due to inadequate compliance with the exercise program. As a result, control data of 22 patients were included. Ankle joint range of active motion, isokinetic muscle strength, pain, quality of life, and photoplethysmography measurements were assessed before starting and after the exercise program. Results Evaluating changes of the starting and control data depending on time showed that all isokinetic muscle strength measurement parameters, range of motion, and overall quality of life values of patients improved. Venous return time values have also increased significantly ( p < 0.05). Conclusion In conclusion, increase in muscle strength has been provided with exercise therapy in patients with chronic venous insufficiency. It has been determined that the increase in muscle strength affected the venous pump and this ensured improvement in venous function and range of motion of the ankle. In addition, it has been detected that pain reduced and quality of life improved after the exercise program.

Eye Tracking of Occluded Self-Moved Targets: Role of Haptic Feedback and Hand-Target Dynamics.

PubMed

Danion, Frederic; Mathew, James; Flanagan, J Randall

2017-01-01

Previous studies on smooth pursuit eye movements have shown that humans can continue to track the position of their hand, or a target controlled by the hand, after it is occluded, thereby demonstrating that arm motor commands contribute to the prediction of target motion driving pursuit eye movements. Here, we investigated this predictive mechanism by manipulating both the complexity of the hand-target mapping and the provision of haptic feedback. Two hand-target mappings were used, either a rigid (simple) one in which hand and target motion matched perfectly or a nonrigid (complex) one in which the target behaved as a mass attached to the hand by means of a spring. Target animation was obtained by asking participants to oscillate a lightweight robotic device that provided (or not) haptic feedback consistent with the target dynamics. Results showed that as long as 7 s after target occlusion, smooth pursuit continued to be the main contributor to total eye displacement (∼60%). However, the accuracy of eye-tracking varied substantially across experimental conditions. In general, eye-tracking was less accurate under the nonrigid mapping, as reflected by higher positional and velocity errors. Interestingly, haptic feedback helped to reduce the detrimental effects of target occlusion when participants used the nonrigid mapping, but not when they used the rigid one. Overall, we conclude that the ability to maintain smooth pursuit in the absence of visual information can extend to complex hand-target mappings, but the provision of haptic feedback is critical for the maintenance of accurate eye-tracking performance.

Eye Tracking of Occluded Self-Moved Targets: Role of Haptic Feedback and Hand-Target Dynamics

PubMed Central

Mathew, James

2017-01-01

Abstract Previous studies on smooth pursuit eye movements have shown that humans can continue to track the position of their hand, or a target controlled by the hand, after it is occluded, thereby demonstrating that arm motor commands contribute to the prediction of target motion driving pursuit eye movements. Here, we investigated this predictive mechanism by manipulating both the complexity of the hand-target mapping and the provision of haptic feedback. Two hand-target mappings were used, either a rigid (simple) one in which hand and target motion matched perfectly or a nonrigid (complex) one in which the target behaved as a mass attached to the hand by means of a spring. Target animation was obtained by asking participants to oscillate a lightweight robotic device that provided (or not) haptic feedback consistent with the target dynamics. Results showed that as long as 7 s after target occlusion, smooth pursuit continued to be the main contributor to total eye displacement (∼60%). However, the accuracy of eye-tracking varied substantially across experimental conditions. In general, eye-tracking was less accurate under the nonrigid mapping, as reflected by higher positional and velocity errors. Interestingly, haptic feedback helped to reduce the detrimental effects of target occlusion when participants used the nonrigid mapping, but not when they used the rigid one. Overall, we conclude that the ability to maintain smooth pursuit in the absence of visual information can extend to complex hand-target mappings, but the provision of haptic feedback is critical for the maintenance of accurate eye-tracking performance. PMID:28680964

Endovascular treatment of post-thrombotic and non-thrombotic iliofemoral venous outflow obstructions with self-expanding nitinol stents.

PubMed

Stuck, Anna K; Reich, Thomas; Engelberger, Rolf P; Sebastian, Tim; Kucher, Nils

2018-06-01

The aim of the study was to investigate venous patency and clinical outcomes for endovascular treatment of iliofemoral venous obstruction in patients with post-thrombotic syndrome (PTS) and non-thrombotic iliac vein lesion (NIVL) with dedicated self-expanding nitinol stents. Data were collected from the prospective Swiss Venous Stent Registry, enrolling consecutive patients with a standardized follow-up procedure since January 2008. Patency was evaluated by duplex sonography and clinical outcome by various scores including the Villalta score at baseline, three, six, and 12 months, and then annually after endovascular therapy. Overall, 93 patients (64 PTS, 29 NIVL) were analysed. Mean follow-up time was 20 ± 16 (range 3-70) months. A total of 11 (12 %) patients had a stent occlusion, all of which occurred in the PTS group, and 13 (14 %) patients had a symptomatic stent stenosis. Primary patency was 79 % (95 % CI 68-87 %) at 12 months and 72 % (95 % CI 59-82 %) at 24 months. In PTS patients, primary patency at 12 months was 75 % (95 % CI 61-84 %) vs. 89 % (95 % CI 63-97 %) in NIVL patients (p = 0.10). Secondary patency at 24 months was 94 % (95 % CI 84-98 %) in PTS and 100 % in NIVL, p = 0.19). Overall, 62 (67 %) patients were free from PTS at the latest follow-up with a Villalta score < 5 points. Predictive factors for the loss of primary patency were stents placed below the inguinal ligament (OR 2.59, 95 % CI, 0.99-6.84, p = 0.05). In symptomatic patients with chronic iliofemoral vein obstruction, endovascular therapy with self-expanding nitinol stents was associated with favourable patency rates and clinical improvement in the majority of patients.

Detection of deep venous thrombophlebitis by gallium 67 scintigraphy

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

Miller, J.H.

1981-07-01

Deep venous thrombophlebitis may escape clinical detection. Three cases are reported in which whole-body gallium 67 scintigraphy was used to detect unsuspected deep venous thrombophlebitis related to indwelling catheters in three children who were being evaluated for fevers of unknown origin. Two of these children had septicemia from Candida organisms secondary to these venous lines. Gallium 67 scintigraphy may be useful in the detection of complications of indwelling venous catheters.

Detection of deep venous thrombophlebitis by Gallium 67 scintigraphy

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

Miller, J.H.

1981-07-01

Deep venous thrombophlebitis may escape clinical detection. Three cases are reported in which whole-body gallium 67 scintigraphy was used to detect unsuspected deep venous thrombophlebitis related to indwelling catheters in three children who were being evaluated for fevers of unknown origin. Two of these children had septicemia from Candida organisms secondary to these venous lines. Gallium 67 scintigraphy may be useful in the detection of complications of indwelling venous catheters.

A randomized controlled trial of a mixed Kinesio taping-compression technique on venous symptoms, pain, peripheral venous flow, clinical severity and overall health status in postmenopausal women with chronic venous insufficiency.

PubMed

Aguilar-Ferrándiz, M Encarnación; Castro-Sánchez, Adelaida María; Matarán-Peñarrocha, Guillermo A; Guisado-Barrilao, Rafael; García-Ríos, M Carmen; Moreno-Lorenzo, Carmen

2014-01-01

To investigate the effect of a mixed Kinesio taping treatment in women with chronic venous insufficiency. A double-blinded randomized clinical trial. Clinical setting. One hundred and twenty postmenopausal women with mild-moderate chronic venous insufficiency were randomly assigned to an experimental group receiving standardized Kinesio taping treatment for gastrocnemius muscle enhancement and ankle functional correction, or to a placebo control group for simulated Kinesio taping. MAIN OUTCOMES VARIABLES: Venous symptoms, pain, photoplethysmographic measurements, bioelectrical impedance, temperature, severity and overall health were recorded at baseline and after four weeks of treatment. The 2 × 2 mixed model ANCOVA with repeated measurements showed statistically significant group * time interaction for heaviness (F = 22.99, p = 0.002), claudication (F = 8.57, p = 0.004), swelling (F = 22.58, p = 0.001), muscle cramps (F = 7.14, p = 0.008), venous refill time (right: F = 9.45, p = 0.023; left: F = 14.86, p = 0.001), venous pump function (right: F = 35.55, p = 0.004; left: F = 17.39 p = 0.001), extracellular water (right: F = 35.55, p = 0.004; left: F = 23.84, p = 0.001), severity (F = 18.47, p = 0.001), physical function (F = 9.15, p = 0.003) and body pain (F = 3.36, p = 0.043). Both groups reported significant reduction in pain. Mixed Kinesio taping-compression therapy improves symptoms, peripheral venous flow and severity and slightly increases overall health status in females with mild chronic venous insufficiency. Kinesio taping may have a placebo effect on pain.

Part-time occlusion therapy for amblyopia in older children

PubMed Central

Singh, Inderpreet; Sachdev, Nishant; Kaushik, Sushmita

2008-01-01

Aim: To compare the efficacy of part-time versus full-time occlusion for treatment of amblyopia in children aged 7-12 years. Materials and Methods: Prospective interventional case series. One hundred children between 7-12 years of age with anisometropic (57), strabismic (25) and mixed (18) unilateral amblyopia were randomized (simple randomization) into four groups (25 each) to receive two hours, four hours, six hours or full-time occlusion therapy. Children were regularly followed up at six-weekly intervals for a minimum of three visits. Statistical Analysis: Intragroup visual improvement was analyzed using paired t-test while intergroup comparisons were done using ANOVA and unpaired t-test. Results: All four groups showed significant visual improvement after 18 weeks of occlusion therapy (P<0.001). Seventy-three (73%) of the total 100 eyes responded to amblyopia therapy with 11 eyes (44%), 17 eyes (68%), 22 eyes (88%) and 23 eyes (92%) being amblyopia responders in the four groups respectively, with the least number of responders in the two hours group. In mild to moderate amblyopia (vision 20/30 to 20/80), there was no significant difference in visual outcome among the four groups (P=0.083). However, in severe amblyopia (vision 20/100 or worse), six hours (P=0.048) and full-time occlusion (P=0.027) treatment were significantly more effective than two hours occlusion. Conclusion: All grades of part-time occlusion are comparable to full-time occlusion in effectiveness of treatment for mild to moderate amblyopia in children between 7-12 years of age unlike in severe amblyopia, where six hours and full-time occlusion were more effective than two hours occlusion therapy. PMID:18974515

Part-time occlusion therapy for amblyopia in older children.

PubMed

Singh, Inderpreet; Sachdev, Nishant; Brar, Gagandeep S; Kaushik, Sushmita

2008-01-01

To compare the efficacy of part-time versus full-time occlusion for treatment of amblyopia in children aged 7-12 years. Prospective interventional case series. One hundred children between 7-12 years of age with anisometropic (57), strabismic (25) and mixed (18) unilateral amblyopia were randomized (simple randomization) into four groups (25 each) to receive two hours, four hours, six hours or full-time occlusion therapy. Children were regularly followed up at six-weekly intervals for a minimum of three visits. Intragroup visual improvement was analyzed using paired t-test while intergroup comparisons were done using ANOVA and unpaired t-test. All four groups showed significant visual improvement after 18 weeks of occlusion therapy ( P < 0.001). Seventy-three (73%) of the total 100 eyes responded to amblyopia therapy with 11 eyes (44%), 17 eyes (68%), 22 eyes (88%) and 23 eyes (92%) being amblyopia responders in the four groups respectively, with the least number of responders in the two hours group. In mild to moderate amblyopia (vision 20/30 to 20/80), there was no significant difference in visual outcome among the four groups ( P =0.083). However, in severe amblyopia (vision 20/100 or worse), six hours ( P =0.048) and full-time occlusion ( P =0.027) treatment were significantly more effective than two hours occlusion. All grades of part-time occlusion are comparable to full-time occlusion in effectiveness of treatment for mild to moderate amblyopia in children between 7-12 years of age unlike in severe amblyopia, where six hours and full-time occlusion were more effective than two hours occlusion therapy.

A study to evaluate patterns of superficial venous reflux in patients with primary chronic venous disease.

PubMed

Qureshi, Mahim I; Gohel, Manj; Wing, Louise; MacDonald, Andrew; Lim, Chung S; Ellis, Mary; Franklin, Ian J; Davies, Alun H

2015-08-01

This study assessed patterns of superficial reflux in patients with primary chronic venous disease. Retrospective review of all patient venous duplex ultrasonography reports at one institution between 2000 and 2009. Legs with secondary, deep or no superficial reflux were excluded. In total, 8654 limbs were scanned; 2559 legs from 2053 patients (mean age 52.3 years) were included for analysis. Great saphenous vein reflux predominated (68%), followed by combined great saphenous vein/small saphenous vein reflux (20%) and small saphenous vein reflux (7%). The majority of legs with competent saphenofemoral junction had below-knee great saphenous vein reflux (53%); incompetent saphenofemoral junction was associated with combined above and below-knee great saphenous vein reflux (72%). Isolated small saphenous vein reflux was associated with saphenopopliteal junction incompetence (61%), although the majority of all small saphenous vein reflux limbs had a competent saphenopopliteal junction (57%). Superficial venous reflux does not necessarily originate from a saphenous junction. Large prospective studies with interval duplex ultrasonography are required to unravel the natural history of primary chronic venous disease. © The Author(s) 2014.

Occlusal plane location in edentulous patients: a review.

PubMed

Shetty, Sanath; Zargar, Nazia Majeed; Shenoy, Kamalakanth; Rekha, V

2013-09-01

Occlusal plane orientation is an important factor in the construction of a complete denture. Occlusal plane could be oriented using landmarks in the mandibular arch as well as in the maxillary arch. In the mandibular arch there are few landmarks which could be used to orient the occlusal plane like the retromolar pad, corner of the lips (lower lip length) whereas the maxillary arch has a number of landmarks, of which the ala-tragal line is the most commonly used and the same being the most controversial. In the following article different landmarks and its accuracy for orientating the occlusal plane in an edentulous subject as studied by various authors has been discussed.

Diagnosis of non-occlusive acute mesenteric ischemia in the intensive care unit.

PubMed

Bourcier, Simon; Oudjit, Ammar; Goudard, Geoffrey; Charpentier, Julien; Leblanc, Sarah; Coriat, Romain; Gouya, Hervé; Dousset, Bertrand; Mira, Jean-Paul; Pène, Frédéric

2016-12-01

Non-occlusive mesenteric ischemia (NOMI) is a common complication and accounts for a major cause of death in critically ill patients. The diagnosis of NOMI with respect to the eventual indications for surgical treatment is challenging. We addressed the performance of the diagnostic strategy of NOMI in the intensive care unit, with emphasis on contrast-enhanced abdominal CT-scan. This was a retrospective monocenter study. Patients with clinically suspected acute mesenteric ischemia were included if a comprehensive diagnostic workup was carried out including surgical and/or endoscopic digestive explorations. Patients with evidence of occlusive mesenteric ischemia were excluded. A definite diagnosis of NOMI only relied on surgical or endoscopic findings. Abdominal CT-scans were reviewed by two radiologists blinded from the final diagnosis. A diagnosis of NOMI could be definitely confirmed or ruled out through surgical or endoscopic explorations of the digestive tract in 147 patients. With respect to their clinical characteristics, only a history of atrial fibrillation was an independent predictor of NOMI (odds ratio 8.3, 95% confidence interval 2.0-35.2, p = 0.004). Among them, 114 patients (75 with and 39 without NOMI) had previously been subjected to contrast-enhanced abdominal CT-scan. Portal venous gas, pneumatosis intestinalis and, to a lesser extent, abnormal contrast-induced bowel wall enhancement were poorly sensitive, but exhibited good specificities of 95, 85 and 71%, respectively. Nineteen out of 75 patients (25.3%) without any suggestive radiological signs finally exhibited mesenteric ischemia, including ten with intestinal necrosis. The performance of abdominal CT-scan for the diagnosis of NOMI is limited. Radiological signs of advanced-stage ischemia are good predictors of definite mesenteric ischemia, while their absence should not be considered sufficient to rule out the diagnosis.

Osteogenesis imperfecta with right renal artery occlusion

PubMed Central

Vaish, Arvind Kumar; Kumar, Nitin; Jain, Nirdesh; Agarwal, Abhishek

2012-01-01

We here report a case of osteogenesis imperfecta who presented with severe hypertension and left ventricular failure and had right renal artery occlusion. The case is very interesting as renal artery occlusion has not been reported earlier in osteogenesis imperfecta. PMID:22962392

A possible association of idiopathic osteosclerosis with excessive occlusal forces.

PubMed

Misirlioglu, Melda; Nalcaci, Rana; Baran, Ilgi; Adisen, Mehmet Zahit; Yilmaz, Selmi

2014-03-01

The aim of the study was to determine the relationship between idiopathic osteosclerotic lesions and occlusal forces using the T-Scan II computerized occlusal analysis device, and to test the sensitivity of the system in occlusal analysis. The study was conducted with 21 volunteers with idiopathic osteosclerosis (IO; 14 women, 7 men) aged between 17 and 62 years (mean 29.95). For every patient, seven or eight recordings were made with the T-Scan II occlusal analysis device in maximum intercuspation, and the last two (excluding any with technical problems) were chosen for evaluation. For each lesion-related area, the distribution of high occlusal forces from two different movies was analyzed. In 18 patients (85.71%), lesions were observed in an area of high occlusal force, and in 13 patients (61.9%), the lesions were located at the first area subjected to high occlusal forces. The percentage distribution of high forces at a lesion related area ranged from 0% to 88%. On average, the high forces at an osteosclerotic lesion area accounted for 20% of the maximum total force. No statistical differences were observed between the measurements of the two selected recordings (P > .05). The findings of this study suggest a possible relationship between IO and occlusal forces and primary contacts. T-Scan II was found to be a successful diagnostic device for detecting primary contacts and excessive occlusal forces.

Three-dimensional venous anatomy of the dermis observed using stereography

PubMed Central

Imanishi, Nobuaki; Kishi, Kazuo; Chang, Hak; Nakajima, Hideo; Aiso, Sadakazu

2008-01-01

Veins of the dermis have been investigated mainly by histological methods in the fields of anatomy and histology, and a large number of schemata of the veins have been depicted in a variety of textbooks. However, the schemata are usually two-dimensional and it is therefore difficult to envisage the actual vasculature of the dermal veins. In this study, we performed a stereographic study of the skin of three fresh cadavers that had been injected with radio-opaque dye, which was dispersed throughout the entire body. A venous network consisting of venous polygons of various sizes existed just under the dermis or in the deep zone of the dermis, which is generally called the subdermal venous plexus. There were many small vessels towards the inside of each venous polygon, and most of them ascended, branching off stereoscopically. Those branches anastomosed with each other, and they formed the dermal and subpapillary venous plexuses. However, there was little vascular connection between dermal venous plexuses of different venous polygons. The characteristic structure of the dermal venous plexus has been considered to bring about venous congestion of the skin in various clinical situations. PMID:18422525

Post-thrombotic syndrome after central venous catheter removal in childhood cancer survivors is associated with a history of obstruction.

PubMed

Revel-Vilk, Shoshana; Menahem, Motti; Stoffer, Chanie; Weintraub, Michael

2010-07-15

A potential long-term complication of central venous catheter (CVC)-related deep vein thrombosis (DVT), both symptomatic and asymptomatic, is development of post-thrombotic syndrome (PTS) characterized by persistent pain, swelling, and skin changes. Signs and symptoms of PTS were reported after CVC removal. The aim of this study was to assess the risk factors for development of PTS in childhood cancer survivors. Children followed at the after cancer follow-up clinic were enrolled. The patients were screened for PTS using Kuhle's PTS pediatric score. Patient's records were retrospectively reviewed for clinical and CVC-related data. Fifty-one children were enrolled at a median of 2.3 (range 0.33-7.5) years after removal of their CVC. The median age of the children the time of treatment was 6.5 (range 0.25-18) years. Mild PTS was present in 20 children (39%, 95% CI 26-54%). Pain symptoms were reported in five children (9.5%, 95% CI 3.3-21.4%). Higher rate of PTS was found in children with history of CVC occlusion. The odd ratio (95% CI) for PTS in children with history of occlusion was 3.7 (95% CI 1.1-12.5%) (P = 0.029). The occurrence of PTS was not associated with age at the time of treatment, time from CVC removal, duration of CVC, and history of infection. Screening cancer survivors for PTS after CVC removal should be integrated to the after cancer follow-up clinic. Obstruction of CVC may indicate for asymptomatic DVT. Whether thromboprophylaxis and/or prevention of CVC occlusion can decrease the rate of PTS needs to be studied.

Accuracy of chest radiography for positioning of the umbilical venous catheter.

PubMed

Guimarães, Adriana F M; Souza, Aline A C G de; Bouzada, Maria Cândida F; Meira, Zilda M A

To evaluate the accuracy of the simultaneous analysis of three radiographic anatomical landmarks - diaphragm, cardiac silhouette, and vertebral bodies - in determining the position of the umbilical venous catheter distal end using echocardiography as a reference standard. This was a cross-sectional, observational study, with the prospective inclusion of data from all neonates born in a public reference hospital, between April 2012 and September 2013, submitted to umbilical venous catheter insertion as part of their medical care. The position of the catheter distal end, determined by the simultaneous analysis of three radiographic anatomical landmarks, was compared with the anatomical position obtained by echocardiography; sensitivity, specificity, positive predictive value, negative predictive value, and accuracy were calculated. Of the 162 newborns assessed by echocardiography, only 44 (27.16%) had the catheter in optimal position, in the thoracic portion of the inferior vena cava or at the junction of the inferior vena cava with the right atrium. The catheters were located in the left atrium and interatrial septum in 54 (33.33%) newborns, in the right atrium in 26 (16.05%), intra-hepatic in 37 (22.84%), and intra-aortic in-one newborn (0.62%). The sensitivity, specificity and accuracy of the radiography to detect the catheter in the target area were 56%, 71%, and 67.28%, respectively. Anteroposterior radiography of the chest alone is not able to safely define the umbilical venous catheter position. Echocardiography allows direct visualization of the catheter tip in relation to vascular structures and, whenever possible, should be considered to identify the location of the umbilical venous catheter. Copyright © 2016 Sociedade Brasileira de Pediatria. Published by Elsevier Editora Ltda. All rights reserved.

A concept to transfer a therapeutic splint position into permanent occlusion with a customized lingual appliance.

PubMed

Sachse, Tina; Schwestka-Polly, Rainer; Flieger, Stefanie; Wiechmann, Dirk

2012-05-21

The role of occlusion concerning temporomandibular disorder is still unclear but seems to be the only component of the stomathognathic system dentists are able to change morphologically. The aim of the paper is to describe the orthodontist's approach for transferring and maintaining a therapeutic splint position into permanent occlusion using a fully customized lingual appliance. Fixed acrylic bite planes on lower molars were used to maintain a symptom-free condyle position prior to orthodontic treatment. Silicone impressions of the arches including the fixed bite planes were used for the Incognito laboratory procedure. Two digital setups were made. One setup represents the target occlusion. A second setup including the bite planes was used to fabricate an additional set of lower molar brackets. In the leveling stage all teeth except the lower molars were settled to maintain the therapeutic condyle position. Finally, the fixed bite planes were stepwise removed and molar brackets were replaced to establish the permanent occlusion planned with the first setup. The advantage of an individual lingual appliance consists in the high level of congruence between the fabricated setups and the final clinical result. Both the individual scope for design and the precision of the appliance were vitally important in the treatment of a patient with a functional disorder of the masticatory system.

Venous thromboembolism prophylaxis in gynecologic surgery: a systematic review.

PubMed

Rahn, David D; Mamik, Mamta M; Sanses, Tatiana V D; Matteson, Kristen A; Aschkenazi, Sarit O; Washington, Blair B; Steinberg, Adam C; Harvie, Heidi S; Lukban, James C; Uhlig, Katrin; Balk, Ethan M; Sung, Vivian W

2011-11-01

To comprehensively review and critically assess the available gynecologic surgery venous thromboembolism prophylaxis literature and provide clinical practice guidelines. MEDLINE and Cochrane databases from inception to July 2010. We included randomized controlled trials in gynecologic surgery populations. Interventions and comparators included graduated compression stockings, intermittent pneumatic compression, unfractionated heparin, and low molecular weight heparin; placebo and routine postoperative care were allowed as comparators. One thousand two hundred sixty-six articles were screened, and 14 randomized controlled trials (five benign gynecologic, nine gynecologic oncology) met eligibility criteria. In addition, nine prospective or retrospective studies with at least 150 women were identified and provided data on venous thromboembolism risk stratification, gynecologic laparoscopy, and urogynecologic populations. Two reviewers independently screened articles with discrepancies adjudicated by a third. Eligible randomized controlled trials were extracted for these characteristics: study, participant, surgery, intervention, comparator, and outcomes data, including venous thromboembolism incidence and bleeding complications. Studies were individually and collectively assessed for methodologic quality and strength of evidence. Overall incidence of clinical venous thromboembolism was 0-2% in the benign gynecologic population. With use of intermittent pneumatic compression for benign major procedures, venous thromboembolism incidence was less than 1%. No venous thromboembolisms were identified in prospective studies of benign laparoscopic procedures. Overall quality of evidence in the benign gynecologic literature was poor. Gynecologic-oncology randomized controlled trials reported venous thromboembolism incidence (including "silent" venous thromboembolisms) of 0-14.8% with prophylaxis and up to 34.6% without prophylaxis. Fair quality of evidence supports that

Occlusal contact of fixed implant prostheses using functional bite impression technique.

PubMed

Suzuki, Yasunori; Shimpo, Hidemasa; Ohkubo, Chikahiro

2015-02-01

Functional bite impression (FBI) has been described as a definitive impression made under occlusal force after functional generated path (FGP) recording. This study compared the accuracy of occlusal contact of implant-fixed prostheses using the FBI technique and the conventional impression technique. Twelve subjects, each missing a single premolar or molar, were selected for this study. The conditions of the occlusal contacts were identified by the modified transillumination method. The occlusal contact condition was determined by comparing the rate of change in the occlusal contact area of the implant-fixed prostheses and both adjacent teeth before and after occlusal adjustment. The rate of change in the occlusal contact area using the FBI technique was 96%, and the rate using the conventional technique was 54%. The occlusal contact of implant prostheses using the FBI technique revealed better accuracy than that of the conventional technique. Regarding the FBI technique, a precise and functional prosthesis could be produced by completing the maxillomandibular registration, impression, and FGP at the same time.

21 CFR 870.2890 - Vessel occlusion transducer.

Code of Federal Regulations, 2011 CFR

2011-04-01

... 21 Food and Drugs 8 2011-04-01 2011-04-01 false Vessel occlusion transducer. 870.2890 Section 870.2890 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES CARDIOVASCULAR DEVICES Cardiovascular Monitoring Devices § 870.2890 Vessel occlusion...

21 CFR 870.2890 - Vessel occlusion transducer.

Code of Federal Regulations, 2010 CFR

2010-04-01

... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Vessel occlusion transducer. 870.2890 Section 870.2890 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES CARDIOVASCULAR DEVICES Cardiovascular Monitoring Devices § 870.2890 Vessel occlusion...

A proof-of-concept study of the VeinScrew: A new percutaneous venous closure device.

PubMed

Boersma, Doeke; de Borst, Gert Jan; Moll, Frans L

2017-02-01

Objective This study evaluated the concept of percutaneous closure of insufficient veins using the VeinScrew principle. Methods The VeinScrew is designed to place a spring-shaped implant that contracts and clamps around the vein. The ability of the device to occlude adequately was tested in a bench model experiment. The feasibility of accurate placement and adequate venous occlusion was evaluated in an animal experiment and in a human cadaveric experiment. Results The VeinScrew implant occluded up to a pressure of 135 mmHg. In vivo studies confirmed that deployment was challenging but technically feasible, and subsequent phlebography showed closure of the vein. The cadaveric study showed that percutaneous placement of the evolved VeinScrew around the great saphenous vein was feasible and accurate. Conclusions The current studies show the feasibility of the VeinScrew concept. Future developments and translational studies are necessary to determine the potential of this technique as a new option in the phlebologist's toolbox.

Endovascular recanalization of a port catheter-associated superior vena cava syndrome.

PubMed

Tonak, Julia; Fetscher, Sebastian; Barkhausen, Jörg; Goltz, Jan Peter

2015-01-01

Superior vena cava (SVC) syndrome owing to benign etiology is rare and endovascular techniques have been advocated as the treatment of choice. We report a case of endovascular revascularization of a port catheter-associated complete occlusion of the SVC with reversed flow in the azygos vein. In this setting using a sheath in combination with its dilatator to pass the occlusion of the SVC after neither a diagnostic catheter nor a PTA balloon would pass the lesion may be a valid option. A dual venous approach was established using the right common femoral vein and an indwelling port catheter in the right cephalic vein to dilate and stent the lesion. Finally, a port may be implanted after the revascularization had been successful. Passage through the port catheter-associated occlusion of the SVC was only possible by use of the sheath in combination with its dilatator. A dual venous access by the femoral approach and the indwelling central catheter is helpful in treating a SVC occlusion. Long-term central venous catheters may cause SVC syndrome, especially with a catheter tip located too far cranially. An endovascular revascularization of a complete occlusion of the SVC represents the therapy of choice.

Does compliance with amblyopia management improve following supervised occlusion treatment?

PubMed

El-Ghrably, I A; Longville, D; Gnanaraj, L

2007-01-01

To demonstrate improvement in compliance following supervised occlusion therapy for amblyopia in children who had failed to respond to outpatient treatment. Retrospective review of the visual outcome of 30 children who were admitted to an ophthalmology ward for 1-day intensive supervised occlusion. These children had documented poor compliance and previously failed to respond to the outpatient occlusion treatment. During their stay a trained ophthalmology nurse educated parents regarding amblyopia and the benefits of occlusion therapy. Visual acuity (VA) of the amblyopic and fellow eyes was recorded on admission, discharge, and at each subsequent visit. The compliance was recorded from parent's history and also indirectly by noticing improvement in vision. The mean supervised occlusion was 7.4 hours (range 4-12 hours). The compliance with occlusion therapy improved in 23 children (77%) after discharge. The mean duration of occlusion after discharge improved to 4 hours (range 1-12 hours). The mean follow-up was 18 months (range 4-24 months). Though there was no dramatic improvement in VA at discharge there was a statistically significant improvement in VA between admission and last recorded VA (p<0.0001). Of the 23 children who were compliant with occlusion following discharge, 21 (91%) gained at least one line of acuity in their amblyopic eye on the last assessment of their VA and five of them achieved 6/12. Of the seven children who did not comply with occlusion following discharge, only one patient gained one line improvement in his amblyopic eye. This study shows that supervised occlusion treatment and parental education was effective in children who had initially failed traditional outpatient treatment.

[Cilioretinal artery occlusion and central retinal vein occlusion complicating hyperhomocysteinemia: a case report].

PubMed

Berkani, Z; Kitouni, Y; Belhadj, A; Sifi, K; Abbadi, N; Bellatrache, C; Hartani, D; Kherroubi, R

2013-09-01

Hyperhomocysteinemia is known to be a risk factor in both retinal artery and retinal vein occlusions. We report the case of a young patient with combined occlusion of the cilioretinal artery and the central retinal vein due to hyperhomocysteinemia. A 23-year-old patient without significant medical history, presented for sudden, painless visual loss in the right eye. Ophthalmologic examination revealed best-corrected visual acuity of the right eye 8/10 P2, and 10/10 P2 on the left. Anterior segment exam was normal in both eyes, while the right fundus revealed white, ischemic edema, centered around a cilioretinal artery, sparing the fovea, with some hemorrhagic spots and disc edema. Fluorescein angiography confirmed delayed filling of the right cilioretinal artery and revealed a normal disc on the left. Two weeks later, the clinical picture had evolved into a right ischemic CRVO, confirmed by a second angiogram, with a decrease in visual acuity to 3/10. A work-up was performed, including: a full lipid profile, serum electrolytes, ESR, CRP, a complete blood count (leukocytes, platelets, hemoglobin were normal), a coagulation work-up (PT, PTT, protein C, protein S, antithrombin III, factor V Leiden were normal), ANCA, antiphospholipid antibodies and antinuclear antibodies were negative, and finally cardiology studies (cardiac echo, carotid Doppler) and neurology (brain MRI) were ordered and came back normal. Otherwise, plasma homocysteine was moderately high on two samples, at 18.3 μmol/L and 17.78 μmol/L. Thyroid and renal work-ups were ordered. Urgent PRP was performed, and vitamin therapy (vitB12, vitB6, folic acid) was instituted. The subsequent course was remarkable for recovery of visual acuity to 10/10, P2 with persistence of an inferior altitudinal central scotoma. MTHFR C677T polymorphism was negative. Retinal vascular occlusions (RVO) are serious events, which require investigation for underlying systemic disease, which can be life-threatening. The clinical

Systemic Venous Inflow to the Liver Allograft to Overcome Diffuse Splanchnic Venous Thrombosis

PubMed Central

Darius, Tom; Goffette, Pierre; Lerut, Jan

2015-01-01

Diffuse splanchnic venous thrombosis (DSVT), formerly defined as contraindication for liver transplantation (LT), is a serious challenge to the liver transplant surgeon. Portal vein arterialisation, cavoportal hemitransposition and renoportal anastomosis, and finally combined liver and small bowel transplantation are all possible alternatives to deal with this condition. Five patients with preoperatively confirmed extensive splanchnic venous thrombosis were transplanted using cavoportal hemitransposition (4x) and renoportal anastomosis (1x). Median follow-up was 58 months (range: 0,5 to 130 months). Two patients with previous radiation-induced peritoneal injury died, respectively, 18 days and 2 months after transplantation. The three other patients had excellent long-term survival, despite the fact that two of them needed a surgical reintervention for severe gastrointestinal bleeding. Extensive splanchnic venous thrombosis is no longer an absolute contraindication to liver transplantation. Although cavoportal hemitransposition and renoportal anastomosis undoubtedly are life-saving procedures allowing for ensuring adequate allograft portal flow, careful follow-up of these patients remains necessary as both methods are unable to completely eliminate the complications of (segmental) portal hypertension. PMID:26539214

Intravascular thrombosis as a result of central venous access.

PubMed

Biernacka, Jadwiga; Nestorowicz, Andrzej; Wach, Małgorzata

2002-01-01

Central venous access represents one of the most basic therapeutic procedures in modern medicine. Unfortunately, numerous advantages that result from maintaining a central venous line are accompanied by some complications among which the venous thrombosis is the most significant clinically. The study was designed to assess frequency and natural history of this complication in the setting at a multi profile clinical hospital. Central venous cannulation was performed by a fully qualified anaesthesiologist in every case. There were 887 cannulations and only 5 patients with clinically significant venous thrombosis. The analysis of the collected data allowed us to state that the frequency of intravascular thrombosis is low, but this complication is often associated with extensive impairment of patency of the central veins. Full recanalization is not always achieved regardless of the treatment applied. Pulmonary embolism in the course of central venous thrombosis was diagnosed in one patient only and appeared as a multiple and fine X-ray infiltrates. It seems that in the presence of permanent or even life threatening complications of central venous thrombosis their risk should be minimized by frequent examination of the cannulation site and early initiation of antithrombotic treatment.

21 CFR 878.4020 - Occlusive wound dressing.

Code of Federal Regulations, 2012 CFR

2012-04-01

... 21 Food and Drugs 8 2012-04-01 2012-04-01 false Occlusive wound dressing. 878.4020 Section 878.4020 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES GENERAL AND PLASTIC SURGERY DEVICES Surgical Devices § 878.4020 Occlusive wound dressing...

21 CFR 878.4020 - Occlusive wound dressing.

Code of Federal Regulations, 2014 CFR

2014-04-01

... 21 Food and Drugs 8 2014-04-01 2014-04-01 false Occlusive wound dressing. 878.4020 Section 878.4020 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES GENERAL AND PLASTIC SURGERY DEVICES Surgical Devices § 878.4020 Occlusive wound dressing...

21 CFR 878.4020 - Occlusive wound dressing.

Code of Federal Regulations, 2013 CFR

2013-04-01

... 21 Food and Drugs 8 2013-04-01 2013-04-01 false Occlusive wound dressing. 878.4020 Section 878.4020 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES GENERAL AND PLASTIC SURGERY DEVICES Surgical Devices § 878.4020 Occlusive wound dressing...

Facial expression recognition under partial occlusion based on fusion of global and local features

NASA Astrophysics Data System (ADS)

Wang, Xiaohua; Xia, Chen; Hu, Min; Ren, Fuji

2018-04-01

Facial expression recognition under partial occlusion is a challenging research. This paper proposes a novel framework for facial expression recognition under occlusion by fusing the global and local features. In global aspect, first, information entropy are employed to locate the occluded region. Second, principal Component Analysis (PCA) method is adopted to reconstruct the occlusion region of image. After that, a replace strategy is applied to reconstruct image by replacing the occluded region with the corresponding region of the best matched image in training set, Pyramid Weber Local Descriptor (PWLD) feature is then extracted. At last, the outputs of SVM are fitted to the probabilities of the target class by using sigmoid function. For the local aspect, an overlapping block-based method is adopted to extract WLD features, and each block is weighted adaptively by information entropy, Chi-square distance and similar block summation methods are then applied to obtain the probabilities which emotion belongs to. Finally, fusion at the decision level is employed for the data fusion of the global and local features based on Dempster-Shafer theory of evidence. Experimental results on the Cohn-Kanade and JAFFE databases demonstrate the effectiveness and fault tolerance of this method.

In vitro reproduction of incisal/occlusal cupping/cratering.

PubMed

Dzakovich, John J; Oslak, Robert R

2013-06-01

Occlusal cupping/cratering (depressed dentin surrounded by elevated rims of enamel) has been postulated to be the result of abrasion, bruxism, attrition, acid erosion, stress corrosion, or a combination of these. The primary etiology or the multifactorial sequence of occlusal cupping/cratering remains scientifically unsubstantiated. The purpose of this study was to reproduce occlusal/incisal cupping/cratering in vitro. This study was designed to create cupping/cratering on the occlusal surfaces of extracted human teeth rather than to quantify the amount of lost tooth structure caused by abrasion. One name-brand toothbrush was tested with 2 different dentifrices (of different abrasive potentials [low and high]) and water only (nonabrasive) on extracted human teeth. Six specimens of 4 teeth each (24 teeth) were subjected to horizontal brushing in a 1:1 toothpaste/water slurry and water only. The control group, brushed with water only, demonstrated no visible loss of tooth structure. Each of the specimens brushed with toothpaste, regardless of the degree of abrasivity, demonstrated visible wear of the dentin, resulting in occlusal/incisal cupping/cratering. Pronounced cupping/cratering was caused by horizontal brushing with commercial toothpastes. Brushing in water demonstrated no visual loss of occlusal tooth structure. (J Prosthet Dent 2013;109:384-391). Copyright © 2013 The Editorial Council of the Journal of Prosthetic Dentistry. Published by Mosby, Inc. All rights reserved.

Compliance with occlusion therapy for childhood amblyopia.

PubMed

Wallace, Michael P; Stewart, Catherine E; Moseley, Merrick J; Stephens, David A; Fielder, Alistair R

2013-09-17

Explore compliance with occlusion treatment of amblyopia in the Monitored and Randomized Occlusion Treatment of Amblyopia Studies (MOTAS and ROTAS), using objective monitoring. Both studies had a three-phase protocol: initial assessment, refractive adaptation, and occlusion. In the occlusion phase, participants were instructed to dose for 6 hours/day (MOTAS) or randomized to 6 or 12 hour/day (ROTAS). Dose was monitored continuously using an occlusion dose monitor (ODM). One hundred and fifty-two patients (71 male, 81 female; 122 Caucasian, 30 non-Caucasian) of mean ± SD age 68 ± 18 months participated. Amblyopia was defined as an interocular acuity difference of at least 0.1 logMAR and was associated with anisometropia in 50, strabismus in 44, and both (mixed) in 58. Median duration of occlusion was 99 days (interquartile range 72 days). Mean compliance was 44%, mean proportion of days with no patch worn was 42%. Compliance was lower (39%) on weekends compared with weekdays (46%, P = 0.04), as was the likelihood of dosing at all (52% vs. 60%, P = 0.028). Compliance was lower when attendance was less frequent (P < 0.001) and with prolonged treatment duration (P < 0.001). Age, sex, amblyopia type, and severity were not associated with compliance. Mixture modeling suggested three subpopulations of patch day doses: less than 30 minutes; doses that achieve 30% to 80% compliance; and doses that achieve around 100% compliance. This study shows that compliance with patching treatment averages less than 50% and is influenced by several factors. A greater understanding of these influences should improve treatment outcome. (ClinicalTrials.gov number, NCT00274664).

Imaging of head and neck venous malformations.

PubMed

Flis, Christine M; Connor, Stephen E

2005-10-01

Venous malformations (VMs) are non proliferative lesions that consist of dysplastic venous channels. The aim of imaging is to characterise the lesion and define its anatomic extent. We will describe the plain film, ultrasound (US) (including colour and duplex Doppler), computed tomography (CT), magnetic resonance imaging (MRI), conventional angiographic and direct phlebographic appearances of venous malformations. They will be illustrated at a number of head and neck locations, including orbit, oral cavity, superficial and deep facial space, supraglottic and intramuscular. An understanding of the classification of such vascular anomalies is required to define the correct therapeutic procedure to employ. Image-guided sclerotherapy alone or in combination with surgery is now the first line treatment option in many cases of head and neck venous malformations, so the radiologist is now an integral part of the multidisciplinary management team.

Cardiovascular Pressures with Venous Gas Embolism and Decompression

NASA Technical Reports Server (NTRS)

Butler, B. D.; Robinson, R.; Sutton, T.; Kemper, G. B.

1995-01-01

Venous gas embolism (VGE) is reported with decompression to a decreased ambient pressure. With severe decompression, or in cases where an intracardiac septal defect (patent foramen ovale) exists, the venous bubbles can become arterialized and cause neurological decompression illness. Incidence rates of patent foramen ovale in the general population range from 25-34% and yet aviators, astronauts, and deepsea divers who have decompression-induced venous bubbles do not demonstrate neurological symptoms at these high rates. This apparent disparity may be attributable to the normal pressure gradient across the atria of the heart that must be reversed for there to be flow potency. We evaluated the effects of: venous gas embolism (0.025, 0.05 and 0.15 ml/ kg min for 180 min.) hyperbaric decompression; and hypobaric decompression on the pressure gradient across the left and right atria in anesthetized dogs with intact atrial septa. Left ventricular end-diastolic pressure was used as a measure of left atrial pressure. In a total of 92 experimental evaluations in 22 dogs, there were no reported reversals in the mean pressure gradient across the atria; a total of 3 transient reversals occurred during the peak pressure gradient changes. The reasons that decompression-induced venous bubbles do not consistently cause serious symptoms of decompression illness may be that the amount of venous gas does not always cause sufficient pressure reversal across a patent foramen ovale to cause arterialization of the venous bubbles.

Core content for training in venous and lymphatic medicine.

PubMed

Zimmet, Steven E; Min, Robert J; Comerota, Anthony J; Meissner, Mark H; Carman, Teresa L; Rathbun, Suman W; Jaff, Michael R; Wakefield, Thomas W; Feied, Craig F

2014-10-01

The major venous societies in the United States share a common mission to improve the standards of medical practitioners, the educational goals for teaching and training programs in venous disease, and the quality of patient care related to the treatment of venous disorders. With these important goals in mind, a task force made up of experts from the specialties of dermatology, interventional radiology, phlebology, vascular medicine, and vascular surgery was formed to develop a consensus document describing the Core Content for venous and lymphatic medicine and to develop a core educational content outline for training. This outline describes the areas of knowledge considered essential for practice in the field, which encompasses the study, diagnosis, and treatment of patients with acute and chronic venous and lymphatic disorders. The American Venous Forum and the American College of Phlebology have endorsed the Core Content. © The Author(s) 2014 Reprints and permissions: sagepub.co.uk/journalsPermissions.nav.

Measurement of venous compliance (8-IML-1)

NASA Technical Reports Server (NTRS)

Thirsk, R. B.

1992-01-01

The prime objective of this International Microgravity Laboratory (IML-1) investigation is to measure the bulk compliance (distensibility) of the veins in the lower leg before, during, and after spaceflight. It is of particular interest whether venous compliance over the range of both positive and negative transmural pressures (various states of venous distention and collapse) changes throughout the duration of spaceflight. Information concerning the occurrence and character of compliance changes could have implications for the design of improved antigravity suits and further the understanding of inflight and postflight venous hemodynamics.

Duplex imaging of residual venous obstruction to guide duration of therapy for lower extremity deep venous thrombosis.

PubMed

Stephenson, Elliot J P; Liem, Timothy K

2015-07-01

Clinical trials have shown that the presence of ultrasound-identified residual venous obstruction (RVO) on follow-up scanning may be associated with an elevated risk for recurrence, thus providing a potential tool to help determine the optimal duration of anticoagulant therapy. We performed a systematic review to evaluate the clinical utility of post-treatment duplex imaging in predicting venous thromboembolism (VTE) recurrence and in adjusting duration of anticoagulation. The Ovid MEDLINE Database, Cochrane Central Register of Controlled Trials, Cochrane Database of Systematic Reviews, and Database of Abstracts of Reviews of Effects were queried for the terms residual thrombus or obstruction, duration of therapy, deep vein thrombosis, deep venous thrombosis, DVT, venous thromboembolism, VTE, antithrombotic therapy, and anticoagulation, and 228 studies were selected for review. Six studies determined the rate of VTE recurrence on the basis of the presence or absence of RVO. Findings on venous ultrasound scans frequently remained abnormal in 38% to 80% of patients, despite at least 3 months of therapeutic anticoagulation. In evaluating for VTE recurrence, the definition of RVO varied widely in the literature. Some studies have shown an association between RVO and VTE recurrence, whereas other studies have not. Overall, the presence of RVO is a mild risk factor for recurrence (odds ratio, 1.3-2.0), but only when surveillance imaging is performed soon after the index deep venous thrombosis (3 months). RVO is a mild risk factor for VTE recurrence. The presence or absence of ultrasound-identified RVO has a limited role in guiding the duration of therapeutic anticoagulation. Further research is needed to evaluate its utility relative to other known risk factors for VTE recurrence. Copyright © 2015 Society for Vascular Surgery. Published by Elsevier Inc. All rights reserved.

Combining technologies: a computerized occlusal analysis system synchronized with a computerized electromyography system.

PubMed

Kerstein, Robert B

2004-04-01

Current advances in computer technologies have afforded dentists precision ways to examine occlusal contacts and muscle function. Recently, two separate computer technologies have been synchronized together, so that an operator can record their separate diagnostic data simultaneously. The two systems are: the T Scan II Occlusal Analysis System and the Biopak Electromyography Recording System. The simultaneous recording and playback capacity of these two computer systems allows the operator to analyze and correlate specific occlusal moments to specific electromyographic changes that result from these occlusal moments. This synchronization provides unparalleled evidence of the effect occlusal contact arrangement has on muscle function. Therefore, the occlusal condition of an inserted dental prosthesis or the occlusal scheme of the natural teeth (before and after corrective occlusal adjustments) can be readily evaluated, documented, and quantified for both, quality of occlusal parameters and muscle activity and the responses to the quality of the occlusal condition. This article describes their synchronization and illustrates their use in performing precision occlusal adjustment procedures on two patients: one who demonstrates occlusal disharmony while exhibiting the signs and symptoms of chronic myofascial pain dysfunction syndrome, and the other who had extensive restorative work accomplished but exhibits occlusal discomfort post-operatively.

Melorheostosis with occlusion of dorsalis pedis artery.

PubMed

Ishibe, Motomi; Inoue, Masayuki; Saitou, Katsutoshi

2002-02-01

Melorheostosis is an unusual sclerotic dysplasia of bone. The case of a 51-year-old female patient with melorheostosis and occlusion of the dorsalis pedis artery is described. Although numerous vascular anomalies have been noted in patients with melorheostosis, occlusion of the dorsalis pedis artery has not been reported previously.

Amalric sign: An augur of ophthalmic artery occlusion

PubMed Central

Hande, Prathibha; Sinha, Babi; Nayak, Shivani; Srinivasan, Srilakshmi; Shetty, Jyothi

2017-01-01

A 75-year-old man presented to us with sudden onset of profound vision loss in his right eye and was identified as suffering from an ophthalmic artery occlusion. Apart from the retinal whitening and box-carring of the retinal arteries, there were characteristic triangular patches of retinal whitening in the midperipheral temporal fundus indicating a previous lateral posterior choroidal artery occlusion. The patient was a chronic smoker and had dyslipidemia. The carotid Doppler study showed complete occlusion of the internal carotid artery. The presence of these triangular patches of retinal whitening or amalric sign can therefore herald a more proximal vessel occlusion. Hence such patients require evaluation on an emergency basis. The characteristic features of the patches on fluorescein angiography and indocyanine green angiography are discussed here. PMID:29044080

Amalric sign: An augur of ophthalmic artery occlusion.

PubMed

Hande, Prathibha; Sinha, Babi; Nayak, Shivani; Srinivasan, Srilakshmi; Shetty, Jyothi

2017-10-01

A 75-year-old man presented to us with sudden onset of profound vision loss in his right eye and was identified as suffering from an ophthalmic artery occlusion. Apart from the retinal whitening and box-carring of the retinal arteries, there were characteristic triangular patches of retinal whitening in the midperipheral temporal fundus indicating a previous lateral posterior choroidal artery occlusion. The patient was a chronic smoker and had dyslipidemia. The carotid Doppler study showed complete occlusion of the internal carotid artery. The presence of these triangular patches of retinal whitening or amalric sign can therefore herald a more proximal vessel occlusion. Hence such patients require evaluation on an emergency basis. The characteristic features of the patches on fluorescein angiography and indocyanine green angiography are discussed here.

Venous compression syndrome of internal jugular veins prevalence in patients with multiple sclerosis and chronic cerebro-spinal venous insufficiency.

PubMed

Mandolesi, Sandro; Niglio, Tarcisio; Orsini, Augusto; De Sio, Simone; d'Alessandro, Alessandro; Mandolesi, Dimitri; Fedele, Francesco; d'Alessandro, Aldo

2016-01-01

Analysis of the incidence of Venous Compression Syndrome (VCS) with full block of the flow of the internal jugular veins (IJVs) in patients with Multiple Sclerosis and Chronic cerebro-spinal venous insufficiency. We included 769 patients with MS and CCSVI (299 males, 470 females) and 210 controls without ms and ccsvi (92 males, 118 females). each subject was investigated by echo-color-doppler (ecd). morphological and hemodynamic ecd data were recorded by a computerized mem-net maps of epidemiological national observatory on ccsvi and they were analyzed by mem-net clinical analysis programs. VCS of IJVs occurs in 240 subjects affected by CCSVI and MS (31% of total) and in 12 controls (6% of total). The differences between the two groups are statistical significant (X² = 36.64, p<0.0001). Up to day there are no longitudinal studies that allow us to identify the WC of jugular and/or vertebral veins as etiology of a chronic neurodegenerative disease, but we note that Venous Compression Syndrome of IJVs is strongly associated with MS and CCSVI. Chronic Cerebro-Spinal Venous Insufficiency, Multiple Sclerosis, Venous Compression Syndrome.

Lifetime Risk of Venous Thromboembolism in Two Cohort Studies.

PubMed

Bell, Elizabeth J; Lutsey, Pamela L; Basu, Saonli; Cushman, Mary; Heckbert, Susan R; Lloyd-Jones, Donald M; Folsom, Aaron R

2016-03-01

Greater public awareness of venous thromboembolism may be an important next step for optimizing venous thromboembolism prevention and treatment. "Lifetime risk" is an easily interpretable way of presenting risk information. Therefore, we sought to calculate the lifetime risk of venous thromboembolism (deep vein thrombosis or pulmonary embolism) using data from 2 large, prospective cohort studies: the Cardiovascular Health Study (CHS) and the Atherosclerosis Risk in Communities (ARIC) study. We followed participants aged 45-64 years in ARIC (n = 14,185) and ≥65 in CHS (n = 5414) at baseline visits (1987-1989 in ARIC, 1989-1990 and 1992-1993 in CHS) for incident venous thromboembolism (n = 728 in ARIC through 2011 and n = 172 in CHS through 2001). We estimated lifetime risks and 95% confidence intervals of incident venous thromboembolism using a modified Kaplan-Meier method, accounting for the competing risk of death from other causes. At age 45 years, the remaining lifetime risk of venous thromboembolism in ARIC was 8.1% (95% confidence interval, 7.1-8.7). High-risk groups were African Americans (11.5% lifetime risk), those with obesity (10.9%), heterozygous for the factor V Leiden (17.1%), or with sickle cell trait or disease (18.2%). Lifetime risk estimates differed by cohort; these differences were explained by differences in time period of venous thromboembolism ascertainment. At least 1 in 12 middle-aged adults will develop venous thromboembolism in their remaining lifetime. This estimate of lifetime risk may be useful to promote awareness of venous thromboembolism and guide decisions at both clinical and policy levels. Copyright © 2016 Elsevier Inc. All rights reserved.

Intravitreal triamcinolone acetonide injections in the treatment of retinal vein occlusions.

PubMed

Roth, Daniel B; Cukras, Catherine; Radhakrishnan, Ravi; Feuer, William J; Yarian, David L; Green, Stuart N; Wheatley, Harold M; Prenner, Jonathan

2008-01-01

To report the visual acuity response after intravitreal triamcinolone injection in patients with macular edema due to retinal vein occlusions. Retrospective nonrandomized interventional series of 172 consecutive patients with macular edema due to retinal vein occlusions who were treated with intravitreal triamcinolone acetonide injection. Patients underwent Snellen visual acuity testing and ophthalmoscopic examination at baseline and 1, 3, 6, and 12 months after intravitreal triamcinolone acetonide injection. All subtypes of retinal vein occlusions showed significant improvements in mean visual acuity 1 month after injection. This improvement in visual acuity was maintained over the 12-month period for all but the central retinal vein occlusion group. Seventy-one (41.3%) of the 172 patients received more than one intravitreal triamcinolone injection for unresolved or recurrent macular edema. This study demonstrates a benefit associated with intravitreal triamcinolone acetonide injection for retinal vein occlusions that was maintained by patients with branch retinal vein occlusions and hemiretinal vein occlusions over a 12-month period. Visual acuity improvement was not maintained in patients with central retinal vein occlusions with this course of treatment.

Retinal vein occlusion

MedlinePlus

... of one eye. Exams and Tests Tests to evaluate for vein occlusion include: Exam of the retina after dilating the pupil An eye test that uses a special dye and camera to look at blood flow in the retina and choroid. Intraocular pressure Pupil ...

Effect of venous stenting on intracranial pressure in idiopathic intracranial hypertension.

PubMed

Matloob, Samir A; Toma, Ahmed K; Thompson, Simon D; Gan, Chee L; Robertson, Fergus; Thorne, Lewis; Watkins, Laurence D

2017-08-01

Idiopathic intracranial hypertension (IIH) is characterised by an increased intracranial pressure (ICP) in the absence of any central nervous system disease or structural abnormality and by normal CSF composition. Management becomes complicated once surgical intervention is required. Venous sinus stenosis has been suggested as a possible aetiology for IIH. Venous sinus stenting has emerged as a possible interventional option. Evidence for venous sinus stenting is based on elimination of the venous pressure gradient and clinical response. There have been no studies demonstrating the immediate effect of venous stenting on ICP. Patients with a potential or already known diagnosis of IIH were investigated according to departmental protocol. ICP monitoring was performed for 24 h. When high pressures were confirmed, CT venogram and catheter venography were performed to look for venous stenosis to demonstrate a pressure gradient. If positive, venous stenting would be performed and ICP monitoring would continue for a further 24 h after deployment of the venous stent. Ten patients underwent venous sinus stenting with concomitant ICP monitoring. Nine out of ten patients displayed an immediate reduction in their ICP that was maintained at 24 h. The average reduction in mean ICP and pulsatility was significant (p = 0.003). Six out of ten patients reported a symptomatic improvement within the first 2 weeks. Venous sinus stenting results in an immediate reduction in ICP. This physiological response to venous stenting has not previously been reported. Venous stenting could offer an alternative treatment option in correctly selected patients with IIH.

Role of occlusion in endodontic management: report of two cases.

PubMed

Yu, Christine Y

2004-12-01

The two clinical cases reported demonstrate that traumatic occlusion can play a role in the initiation and progression of pulp and periradicular inflammation. The symptom of persistent pain did not subside after the commencement of endodontic treatment. Traumatic occlusion was identified in both cases to be the main cause and hence occlusal adjustment was performed. This resulted in the gradual resolution of the symptoms. The findings suggest that occlusal trauma is often overlooked in the diagnosis and management of endodontic diseases.

Haptic simulation framework for determining virtual dental occlusion.

PubMed

Wu, Wen; Chen, Hui; Cen, Yuhai; Hong, Yang; Khambay, Balvinder; Heng, Pheng Ann

2017-04-01

The surgical treatment of many dentofacial deformities is often complex due to its three-dimensional nature. To determine the dental occlusion in the most stable position is essential for the success of the treatment. Computer-aided virtual planning on individualized patient-specific 3D model can help formulate the surgical plan and predict the surgical change. However, in current computer-aided planning systems, it is not possible to determine the dental occlusion of the digital models in the intuitive way during virtual surgical planning because of absence of haptic feedback. In this paper, a physically based haptic simulation framework is proposed, which can provide surgeons with the intuitive haptic feedback to determine the dental occlusion of the digital models in their most stable position. To provide the physically realistic force feedback when the dental models contact each other during the searching process, the contact model is proposed to describe the dynamic and collision properties of the dental models during the alignment. The simulated impulse/contact-based forces are integrated into the unified simulation framework. A validation study has been conducted on fifteen sets of virtual dental models chosen at random and covering a wide range of the dental relationships found clinically. The dental occlusions obtained by an expert were employed as a benchmark to compare the virtual occlusion results. The mean translational and angular deviations of the virtual occlusion results from the benchmark were small. The experimental results show the validity of our method. The simulated forces can provide valuable insights to determine the virtual dental occlusion. The findings of this work and the validation of proposed concept lead the way for full virtual surgical planning on patient-specific virtual models allowing fully customized treatment plans for the surgical correction of dentofacial deformities.

Evaluation of the occlusal contact of crowns fabricated with the bite impression method.

PubMed

Makino, Sachi; Okada, Daizo; Shin, Chiharu; Ogura, Reiko; Ikeda, Masaomi; Miura, Hiroyuki

2013-09-30

In prosthodontic treatment, reconstruction of a proper occlusal contact relationship is very important as well as reconstruction of a proper interproximal relationship and marginal fitness. Unfortunately, occlusal relationships are sometimes lost in the process of occlusal adjustment of crowns. The purpose of this study was to compare the occlusal contacts of single crown fabricated by two different types of impression techniques. Nine subjects, whose molars required treatment with crown restoration, were enrolled in this study. Full cast crowns were fabricated using two types of impression techniques: the conventional impression method (CIM) and the bite impression method (BIM). The occlusal contacts of crowns were precisely evaluated at the following stages: after occlusal adjustment on the articulator (Step 0), before occlusal adjustment in the mouth (Step 1), after occlusal adjustment at the intercuspal position (Step 2), and after occlusal adjustment during lateral and protrusive excursions (Step 3). The number of occlusal contacts of the crowns on the functional cusps fabricated with BIM was significantly greater than that with CIM after occlusal adjustment. For this reason, the crowns fabricated with BIM might have a more functionally desirable occlusal surface compared to the crowns fabricated with CIM.

New findings on venous thrombogenesis

PubMed Central

Byrnes, James R.; Wolberg, Alisa S.

2017-01-01

Summary Venous thrombosis (VT) is the third most common cause of cardiovascular death worldwide. Complications from VT and pulmonary embolism are the leading cause of lost disability-adjusted life years. Risks include genetic (e.g., non-O blood group, activated protein C resistance, hyperprothrombinemia) and acquired (e.g., age, surgery, cancer, pregnancy, immobilisation, female hormone use) factors. Pathophysiologic mechanisms that promote VT are incompletely understood, but involve abnormalities in blood coagulability, vessel function, and flow (so-called Virchow’s Triad). Epidemiologic studies of humans, animal models, and biochemical and biophysical investigations have revealed contributions from extrinsic, intrinsic, and common pathways of coagulation, endothelial cells, leukocytes, red blood cells, platelets, cell-derived microvesicles, stasis-induced changes in vascular cells, and blood rheology. Knowledge of these mechanisms may yield new therapeutic targets. Characterisation of mechanisms that mediate VT formation and stability, particularly in aging, are needed to advance understanding of VT. PMID:27878206

[Comparison of 2 lacrimal punctal occlusion methods].

PubMed

Shalaby, O; Rivas, L; Rivas, A I; Oroza, M A; Murube, J

2001-09-01

To study and compare two methods for canalicular occlusion: Cautery and Punctal Patch. The study included fourty patients divided in two groups of 20 patients. The end point was 4 occluded puncti. The first group underwent deep cauterization resulting in occlusion of the full vertical aspect of the canaliculus. The second group underwent punctal patch technique for canalicular occlusion. Differential parameters were the following: time of intervention, ease of use, risks and precision. In the post operatory, discomfort, subjective and objective improvement in ocular surface as well as long term result of each technique was analysed. Time of intervention was longer for punctal patch compared to cautery. Both methods exhibited similar ease of use and improvement in ocular surface. Precision was high in punctal patch technique showing complete and final occlusion and no punctum needed reopening, while cautery technique presented 20% rate of reopening intervention. Postoperatory discomfort and irritation were remarkably evident with punctal technique, while minimal in cautery technique. Survival analysis after one year follow up, showed a higher rate of advantages for punctal patch technique over cautery technique.

Patterns and Rates of Supplementary Venous Drainage to the Internal Jugular Veins.

PubMed

Qureshi, Adnan I; Ishfaq, Muhammad Fawad; Herial, Nabeel A; Khan, Asif A; Suri, M Fareed K

2016-07-01

Several studies have found supplemental venous drainage channels in addition to bilateral internal jugular veins for cerebral venous efflux. We performed this study to characterize the supplemental venous outflow patterns in a consecutive series of patients undergoing detailed cerebral angiography with venous phase imaging. The venographic phase of the arteriogram was reviewed to identify and classify supplemental cerebral venous drainage into anterior (cavernous venous sinus draining into pterygoid plexus and retromandibular vein) and posterior drainage pattern. The posterior drainage pattern was further divided into plexiform pattern (with sigmoid venous sinus draining into the paravertebral venous plexus), and solitary vein pattern (dominant single draining deep cervical vein) drainage. The posterior plexiform pattern was further divided into 2 groups: posterior plexiform with or without prominent solitary vein. Supplemental venous drainage was seen ipsilateral to internal jugular vein in 76 (43.7%) of 174 venous drainages (87 patients) analyzed. The patterns were anterior (n = 23, 13.2%), posterior plexiform without prominent solitary vein (n = 40, 23%), posterior plexiform with prominent solitary vein (n = 62, 35.6%), and posterior solitary vein alone (n = 3, 1.7%); occipital emissary veins and/or transosseous veins were seen in 1 supplemental venous drainage. Concurrent ipsilateral anterior and posterior supplemental drainage was seen in 6 of 174 venous drainages analyzed. We provide an assessment of patterns and rates of supplementary venous drainage to internal jugular veins to improve our understanding of anatomical and physiological aspects of cerebral venous drainage. Copyright © 2016 by the American Society of Neuroimaging.

Acute pancreatitis during sickle cell vaso-occlusive painful crisis.

PubMed

Ahmed, Shahid; Siddiqui, Anita K; Siddiqui, Rina K; Kimpo, Miriam; Russo, Linda; Mattana, Joseph

2003-07-01

Sickle cell disease is characterized by chronic hemolytic anemia and vaso-occlusive painful crisis. The vascular occlusion in sickle cell disease is a complex process and accounts for the majority of the clinical manifestations of the disease. Abdominal pain is an important component of vaso-occlusive painful crisis and may mimic diseases such as acute appendicitis and cholecystitis. Acute pancreatitis is rarely included as a cause of abdominal pain in patients with sickle cell disease. When it occurs it may result form biliary obstruction, but in other instances it might be a consequence of microvessel occlusion causing ischemia. In this series we describe four cases of acute pancreatitis in patients with sickle cell disease apparently due to microvascular occlusion and ischemic injury to the pancreas. All patients responded to conservative management. Acute pancreatitis should be considered in the differential diagnosis of abdominal pain in patients with sickle cell disease. Copyright 2003 Wiley-Liss, Inc.

Venous Return and Clinical Hemodynamics: How the Body Works during Acute Hemorrhage

ERIC Educational Resources Information Center

Shen, Tao; Baker, Keith

2015-01-01

Venous return is a major determinant of cardiac output. Adjustments within the venous system are critical for maintaining venous pressure during loss in circulating volume. This article reviews two factors that are thought to enable the venous system to compensate during acute hemorrhage: 1) changes in venous elastance and 2) mobilization of…

A thrombolytic regimen for high-risk deep venous thrombosis may substantially reduce the risk of postthrombotic syndrome in children

PubMed Central

Goldenberg, Neil A.; Durham, Janette D.; Knapp-Clevenger, R.

2007-01-01

Important predictors of adverse outcomes of thrombosis in children, including postthrombotic syndrome (PTS), have recently been identified. Given this knowledge and the encouraging preliminary pediatric experience with systemic thrombolysis, we sought to retrospectively analyze our institutional experience with a thrombolytic regimen versus standard anticoagulation for acute, occlusive deep venous thrombosis (DVT) of the proximal lower extremities in children in whom plasma factor VIII activity and/or D-dimer concentration were elevated at diagnosis, from within a longitudinal pediatric cohort. Nine children who underwent the thrombolytic regimen and 13 who received standard anticoagulation alone were followed from time of diagnosis with serial clinical evaluation and standardized PTS outcome assessments conducted in uniform fashion. The thrombolytic regimen was associated with a markedly decreased odds of PTS at 18 to 24 months compared with standard anticoagulation alone, which persisted after adjustment for significant covariates of age and lag time to therapy (odds ratio [OR] = 0.018, 95% confidence interval [CI] = < 0.001-0.483; P = .02). Major bleeding developed in 1 child, clinically judged as not directly related to thrombolysis for DVT. These findings suggest that the use of a thrombolysis regimen may safely and substantially reduce the risk of PTS in children with occlusive lower-extremity acute DVT, providing the basis for a future clinical trial. PMID:17360940

Concurrent Angioplasty Balloon Placement for Stent Delivery through Jugular Venous Bulb for Treating Cerebral Venous Sinus Stenosis. Technical Report.

PubMed

Qureshi, Adnan I; Khan, Asif A; Capistrant, Rachel; Qureshi, Mushtaq H; Xie, Kevin; Suri, M Fareed K

2016-10-01

To report upon technique of concurrent placement of angioplasty balloon at the internal jugular vein and sigmoid venous sinus junction to facilitate stent delivery in two patients in whom stent delivery past the jugular bulb was not possible. A 21-year-old woman and a 41-year-old woman with worsening headaches, visual obscuration or diplopia were treated for pseudotumor cerebri associated with transverse venous stenosis. Both patients had undergone primary angioplasty, which resulted in improvement in clinical symptoms followed by the recurrence of symptoms with restenosis at the site of angioplasty. After multiple attempts at stent delivery through jugular venous bulb were unsuccessful, a second guide catheter was placed in the ipsilateral internal jugular vein through contralateral femoral venous approach. A 6 mm × 20 mm (left) or 5 × 15 mm (right) angioplasty balloon was placed across the internal jugular vein and sigmoid sinus junction and partially inflated until the inflation and relative straightening of the junction was observed. In both patients, the internal jugular vein and sigmoid sinus junction was successfully traversed by the stent delivery system in a parallel alignment to inflated balloon. Balloon mounted stent was deployed at the site of restenosis with near complete resolution of lumen narrowing delivery and improvement in clinical symptoms. We report a technique for realignment and diameter change with concurrent placement and partial inflation of angioplasty balloon at the jugular venous bulb to facilitate stent delivery into the sigmoid and transverse venous sinuses in circumstances where multiple attempts at stent delivery are unsuccessful.

Low-dose aspirin for preventing recurrent venous thromboembolism.

PubMed

Brighton, Timothy A; Eikelboom, John W; Mann, Kristy; Mister, Rebecca; Gallus, Alexander; Ockelford, Paul; Gibbs, Harry; Hague, Wendy; Xavier, Denis; Diaz, Rafael; Kirby, Adrienne; Simes, John

2012-11-22

Patients who have had a first episode of unprovoked venous thromboembolism have a high risk of recurrence after anticoagulants are discontinued. Aspirin may be effective in preventing a recurrence of venous thromboembolism. We randomly assigned 822 patients who had completed initial anticoagulant therapy after a first episode of unprovoked venous thromboembolism to receive aspirin, at a dose of 100 mg daily, or placebo for up to 4 years. The primary outcome was a recurrence of venous thromboembolism. During a median follow-up period of 37.2 months, venous thromboembolism recurred in 73 of 411 patients assigned to placebo and in 57 of 411 assigned to aspirin (a rate of 6.5% per year vs. 4.8% per year; hazard ratio with aspirin, 0.74; 95% confidence interval [CI], 0.52 to 1.05; P=0.09). Aspirin reduced the rate of the two prespecified secondary composite outcomes: the rate of venous thromboembolism, myocardial infarction, stroke, or cardiovascular death was reduced by 34% (a rate of 8.0% per year with placebo vs. 5.2% per year with aspirin; hazard ratio with aspirin, 0.66; 95% CI, 0.48 to 0.92; P=0.01), and the rate of venous thromboembolism, myocardial infarction, stroke, major bleeding, or death from any cause was reduced by 33% (hazard ratio, 0.67; 95% CI, 0.49 to 0.91; P=0.01). There was no significant between-group difference in the rates of major or clinically relevant nonmajor bleeding episodes (rate of 0.6% per year with placebo vs. 1.1% per year with aspirin, P=0.22) or serious adverse events. In this study, aspirin, as compared with placebo, did not significantly reduce the rate of recurrence of venous thromboembolism but resulted in a significant reduction in the rate of major vascular events, with improved net clinical benefit. These results substantiate earlier evidence of a therapeutic benefit of aspirin when it is given to patients after initial anticoagulant therapy for a first episode of unprovoked venous thromboembolism. (Funded by National Health

Cardiac veins: collateral venous drainage pathways in chronic hemodialysis patients.

PubMed

Ozmen, Evrim; Algin, Oktay

2016-07-12

Venous anomalies are diagnostic and therapeutic challenges. Subclavian or superior vena cava stenosis can be developed and venous return can be achieved via cardiac veins and coronary sinus in patients with central venous catheter for long-term hemodialysis. These types of abnormalities are not extremely rare especially in patients with a history of central venous catheter placement. Detection of these anomalies and subclavian vein stenosis before the surgical creation of hemodialysis fistulae or tunneled central venous catheter placement may prevent unnecessary interventions in those patients. Multidetector computed tomography (MDCT) technique can give further information when compared with fluoroscopy or digital subtraction angiography in the management of these patients. This case report describes interesting aspects of central vein complications in hemodialysis patients. As a conclusion, there are limited data about thoracic venous return, and further prospective studies with large patient number are required. MDCT with 3D reconstruction is particularly useful for the accurate evaluation of venous patency, variations, and collateral circulation. Also it is an excellent tool for choosing and planning treatment.

Computational evaluation of aortic occlusion and the proposal of a novel, improved occluder: Constrained endo-aortic balloon occlusion.

PubMed

de Vaal, M H; Gee, M W; Stock, U A; Wall, W A

2016-12-01

Because aortic occlusion is arguably one of the most dangerous aortic manipulation maneuvers during cardiac surgery in terms of perioperative ischemic neurological injury, the purpose of this investigation is to assess the structural mechanical impact resulting from the use of existing and newly proposed occluders. Existing (clinically used) occluders considered include different cross-clamps (CCs) and endo-aortic balloon occlusion (EABO). A novel occluder is also introduced, namely, constrained EABO (CEABO), which consists of applying a constrainer externally around the aorta when performing EABO. Computational solid mechanics are employed to investigate each occluder according to a comprehensive list of functional requirements. The potential of a state of occlusion is also considered for the first time. Three different constrainer designs are evaluated for CEABO. Although the CCs were responsible for the highest strains, largest deformation, and most inefficient increase of the occlusion potential, it remains the most stable, simplest, and cheapest occluder. The different CC hinge geometries resulted in poorer performance of CC used for minimally invasive procedures than conventional ones. CEABO with a profiled constrainer successfully addresses the EABO shortcomings of safety, stability, and positioning accuracy, while maintaining its complexities of operation (disadvantage) and yielding additional functionalities (advantage). Moreover, CEABO is able to achieve the previously unattainable potential to provide a clinically determinable state of occlusion. CEABO offers an attractive alternative to the shortcomings of existing occluders, with its design rooted in achieving the highest patient safety. Copyright © 2016 John Wiley & Sons, Ltd. Copyright © 2016 John Wiley & Sons, Ltd.

[Emphysematous gastritis with concomitant portal venous air].

PubMed

Jeong, Min Yeong; Kim, Jin Il; Kim, Jae Young; Kim, Hyun Ho; Jo, Ik Hyun; Seo, Jae Hyun; Kim, Il Kyu; Cheung, Dae Young

2015-02-01

Emphysematous gastritis is a rare form of gastritis caused by infection of the stomach wall by gas forming bacteria. It is a very rare condition that carries a high mortality rate. Portal venous gas shadow represents elevation of intestinal luminal pressure which manifests as emphysematous gastritis or gastric emphysema. Literature reviews show that the mortality rate is especially high when portal venous gas shadow is present on CT scan. Until recently, the treatment of emphysematous gastritis has been immediate surgical intervention. However, there is a recent trend of avoiding surgery because of the frequent occurrence of post-operative complications such as anastomosis leakage. In addition, aggressive surgical treatment has failed to show significant improvement in prognosis. Recently, the authors experienced a case of emphysematous gastritis accompanied by portal venous gas which was treated successfully by conservative treatment without immediate surgical intervention. Herein, we present a case of emphysematous gastritis with concomitant portal venous air along with literature review.

[Venous thromboembolic disease: presentation of a case].

PubMed

Mirpuri-Mirpuri, P G; Álvarez-Cordovés, M M; Pérez-Monje, A

2013-01-01

Venous thromboembolic disease in its clinical spectrum includes both deep vein thrombosis and pulmonary thromboembolism, which is usually a complication of deep vein thrombosis. It is a relatively common disease with significant morbidity and requires an accurate diagnosis. They are numerous risk factors for venous thromboembolism, and there is evidence that the risk of thromboembolic disease increases proportionally to the number of predisposing risk factors present. The primary care physician should know the risk factors and suspect the presence of venous thromboembolic disease when there is a compatible clnical picture. The treatment for this pathology is anticoagulation. We report a patient with cardiovascular risk factors who was seen with pain in the right leg and shortness of breath and referred to the hospital with suspected venous thromboembolism, atrial fibrillation and pleural effusion. Copyright © 2012 Sociedad Española de Médicos de Atención Primaria (SEMERGEN). Publicado por Elsevier España. All rights reserved.

Influence of occlusal contact area on cusp defection and stress distribution.

PubMed

Costa, Anna Karina Figueiredo; Xavier, Thaty Aparecida; Paes-Junior, Tarcisio José Arruda; Andreatta-Filho, Oswaldo Daniel; Borges, Alexandre Luiz Souto

2014-11-01

The purpose of this study was to evaluate the effect of occlusal contact area for loading on the cuspal defection and stress distribution in a first premolar restored with a high elastic modulus restorative material. The Rhinoceros 4.0 software was used for modeling the three-dimensional geometries of dental and periodontal structures and the inlay restoration. Thus, two different models, intact and restored teeth with three occlusal contact areas, 0.1, 0.5 and 0.75 mm(2), on enamel at the occlusal surface of buccal and lingual cusps. Finite element analysis (FEA) was performed with the program ANSYS (Workbench 13.0), which generated a mesh with tetrahedral elements with greater refinement in the regions of interest, and was constrained at the bases of cortical and trabecular bone in all axis and loaded with 100 N normal to each contact area. To analysis of maximum principal stress, the smaller occlusal contact area showed greater compressive stress in region of load application for both the intact and inlay restored tooth. However, tensile stresses at the occlusal isthmus were similar for all three tested occlusal contact areas (60 MPa). To displacement of the cusps was higher for teeth with inlay (0.46-0.48 mm). For intact teeth, the smaller contact area showed greater displacement (0.10 mm). For teeth with inlays, the displacement of the cusps were similar in all types of occlusal area. Cuspal displacement was higher in the restored tooth when compared to the intact tooth, but there were no significant variations even with changes in the occlusal contact area. RELEVANCE CLINICAL: Occlusal contacts have a great influence on the positioning of teeth being able to maintain the position and stability of the mandible. Axial loads would be able to generate more uniform stress at the root presenting a greater concentration of load application in the point and the occlusal surface. Thus, is necessary to analyze the relationship between these occlusal contacts as dental

GAVeCeLT* consensus statement on the correct use of totally implantable venous access devices for diagnostic radiology procedures.

PubMed

Bonciarelli, Giorgio; Batacchi, Stefano; Biffi, Roberto; Buononato, Massimo; Damascelli, Bruno; Ghibaudo, Flavio; Orsi, Franco; Pittiruti, Mauro; Scoppettuolo, Giancarlo; Verzè, Alessia; Borasi, Guido; De Cicco, Marcello; Dosio, Roberto; Gazzo, Paolo; Maso, Renzo; Roman, Alessandro; Ticha, Vladimira; Venier, Giacomo; Blackburn, Paul; Goossens, Godelieve A; Bowen Santolucito, Jamie; Stas, Marguerite; Van Boxtel, Ton; Vesely, Thomas M; de Lutio, Enrico

2011-01-01

The use of totally implantable venous access devices in radiology may be associated with complications such as occlusion of the system (because of the high density of some contrast), infection (if the port is not handled in aseptic conditions, using proper barrier protections), and mechanical complications due to the high-pressure administration of contrast by automatic injectors (so-called power injector), including extravasation of contrast media into the soft tissues, subintimal venous or myocardial injection, or serious damage to the device itself (breakage of the external connections, dislocation of the non-coring needle, or breakage of the catheter). The last problem - i.e., the damage of the device from a power injection - is not an unjustified fear, but a reality. A warning by the US Food and Drug Administration of July 2004 reports around 250 complications of this kind, referring to both port and central venous catheters and peripherally inserted central catheter systems, which occurred over a period of several years; in all cases, the damage occurred during the injection of contrast material by means of power injectors for computed tomography or magnetic resonance imaging procedures. Though the risk associated with the use of ports in radiodiagnostics is thus clear, it has been suggested that administration of the contrast material via the port may have some advantage in terms of image quality, increased comfort for the patient, and maybe more accurate reproducibility of the patient's own follow-up exams. This contention needs to be supported by evidence. Also, since many cancer patients who need frequent computed tomography studies already have totally implantable systems, it would seem reasonable to try to define how and when such systems may safely be used. The purpose of this consensus statement is to define recommendations based on the best available evidence, for the safe use of implantable ports in radiodiagnostics.

Percutaneous intraportal application of adipose tissue-derived mesenchymal stem cells using a balloon occlusion catheter in a porcine model of liver fibrosis.

PubMed

Avritscher, Rony; Abdelsalam, Mohamed E; Javadi, Sanaz; Ensor, Joe; Wallace, Michael J; Alt, Eckhard; Madoff, David C; Vykoukal, Jody V

2013-12-01

To investigate the safety and effectiveness of a novel endovascular approach for therapeutic cell delivery using a balloon occlusion catheter in a large animal model of liver fibrosis. Transcatheter arterial embolization with ethiodized oil (Ethiodol) and ethanol was used to induce liver damage in 11 pigs. Mesenchymal stem cells (MSCs) were harvested from adipose tissue and engineered to express green fluorescent protein (GFP). A balloon occlusion catheter was positioned in the bilateral first-order portal vein branches 2 weeks after embolization to allow intraportal application of MSCs in six experimental animals. MSCs were allowed to dwell for 10 minutes using prolonged balloon inflation. Five control animals received a sham injection of normal saline in a similar fashion. Hepatic venous pressure gradient (HVPG) was measured immediately before necropsy. Specimens from all accessible lobes were obtained with ultrasound-guided percutaneous 18-gauge biopsy 2 hours after cell application. All animals were euthanized within 4 weeks. Fluorescent microscopy was used to assess the presence and distribution of cells. Liver injury and fibrosis were successfully induced in all animals. MSCs (6-10 × 10(7)) were successfully delivered into the portal vein in the six experimental animals. Cell application was not associated with vascular complications. HVPG showed no instances of portal hypertension. GFP-expressing MSCs were visualized in biopsy specimens and were distributed primarily within the sinusoidal spaces; however, 4 weeks after implantation, MSCs could not be identified in histologic specimens. A percutaneous endovascular approach for cell delivery using a balloon occlusion catheter proved safe for intraportal MSC application in a large animal model of liver fibrosis. © 2013 SIR Published by SIR All rights reserved.

Pathophysiology of spontaneous venous gas embolism

NASA Technical Reports Server (NTRS)

Lambertsen, C. J.; Albertine, K. H.; Pisarello, J. B.; Flores, N. D.

1991-01-01

The use of controllable degrees and durations of continuous isobaric counterdiffusion venous gas embolism to investigate effects of venous gas embolism upon blood, cardiovascular, and respiratory gas exchange function, as well as pathological effects upon the lung and its microcirculation is discussed. Use of N2O/He counterdiffusion permitted performance of the pathophysiologic and pulmonary microstructural effects at one ATA without hyperbaric or hypobaric exposures.

Patterns of anomalous pulmonary venous drainage.

PubMed

Snellen, H A; van Ingen, H C; Hoefsmit, E C

1968-07-01

All of our cases of abnormal pulmonary venous connections collected to the middle of 1965 and verified at surgery or autopsy have been reviewed by means of diagrams and tabulations, using a specially devised code to facilitate the survey. The material consisted of 52 autopsy cases (half of them obtained after surgery) and the cases of 72 patients who survived operation. The postmortem group was much younger than the surgical group and differed also from the latter by showing male preponderance as well as relatively many instances of total abnormal pulmonary venous connection and frequently associated cardiac anomalies. Partial anomalous connection of right pulmonary veins was 10 times more frequent than that of the left pulmonary veins. This was caused by (1) the frequent drainage of some of the right pulmonary veins into the junctional area between right atrium and superior vena cava in the presence of normal left pulmonary veins, and (2) the complete absence of isolated left pulmonary venous connection to the right atrium. Abnormal connection of solitary pulmonary veins was always effected to the most proximal venous structure among the four possible ones which are derived from the main embryonic channels (superior vena cava and inferior vena cava on the right side, and left superior vena cava and coronary sinus on the left side). Common pulmonary veins from one lung also drained in accordance with this proximity rule, if this may be taken to apply also to the drainage of right pulmonary veins into the right atrium. The one exception in our material was the drainage of all right pulmonary veins into the portal venous system. Total abnormal pulmonary venous connection may be found with all structures mentioned, but most frequently with the left superior vena cava, or coronary sinus, or both, usually by way of a common pulmonary vein. In a few cases however, drainage into different sites, all of them abnormal, did occur. Then again the proximity rule seemed to

Pentoxifylline for treating venous leg ulcers.

PubMed

Jull, Andrew B; Arroll, Bruce; Parag, Varsha; Waters, Jill

2012-12-12

Healing of venous leg ulcers is improved by the use of compression bandaging but some venous ulcers remain unhealed, and some people are unsuitable for compression therapy. Pentoxifylline, a drug which helps blood flow, has been used to treat venous leg ulcers. To assess the effects of pentoxifylline (oxpentifylline or Trental 400) for treating venous leg ulcers, compared with a placebo or other therapies, in the presence or absence of compression therapy. For this fifth update we searched the Cochrane Wounds Group Specialised Register (searched 20 July 2012); The Cochrane Central Register of Controlled Trials (CENTRAL) (The Cochrane Library 2012, Issue 7); Ovid MEDLINE (2010 to July Week 2 2012); Ovid MEDLINE (In-Process & Other Non-Indexed Citations, July 19, 2012); Ovid EMBASE (2010 to 2012 Week 28); and EBSCO CINAHL (2010 to July 13 2012). Randomised trials comparing pentoxifylline with placebo or other therapy in the presence or absence of compression, in people with venous leg ulcers. One review author extracted and summarised details from eligible trials using a coding sheet. One other review author independently verified data extraction. No new trials were identified for this update. We included twelve trials involving 864 participants. The quality of trials was variable. Eleven trials compared pentoxifylline with placebo or no treatment. Pentoxifylline is more effective than placebo in terms of complete ulcer healing or significant improvement (RR 1.70, 95% CI 1.30 to 2.24). Pentoxifylline plus compression is more effective than placebo plus compression (RR 1.56, 95% CI 1.14 to 2.13). Pentoxifylline in the absence of compression appears to be more effective than placebo or no treatment (RR 2.25, 95% CI 1.49 to 3.39).More adverse effects were reported in people receiving pentoxifylline (RR 1.56, 95% CI 1.10 to 2.22). Nearly three-quarters (72%) of the reported adverse effects were gastrointestinal. Pentoxifylline is an effective adjunct to compression

GMI-1070, a novel pan-selectin antagonist, reverses acute vascular occlusions in sickle cell mice

PubMed Central

Chang, Jungshan; Patton, John T.; Sarkar, Arun; Ernst, Beat

2010-01-01

Leukocyte adhesion in the microvasculature influences blood rheology and plays a key role in vaso-occlusive manifestations of sickle cell disease. Notably, polymorphonuclear neutrophils (PMNs) can capture circulating sickle red blood cells (sRBCs) in inflamed venules, leading to critical reduction in blood flow and vaso-occlusion. Recent studies have suggested that E-selectin expression by endothelial cells plays a key role by sending activating signals that lead to the activation of Mac-1 at the leading edge of PMNs, thereby allowing RBC capture. Thus, the inhibition of E-selectin may represent a valuable target in this disease. Here, we have tested the biologic properties of a novel synthetic pan-selectin inhibitor, GMI-1070, with in vitro assays and in a humanized model of sickle cell vaso-occlusion analyzed by intravital microscopy. We have found that GMI-1070 predominantly inhibited E-selectin–mediated adhesion and dramatically inhibited sRBC-leukocyte interactions, leading to improved microcirculatory blood flow and improved survival. These results suggest that GMI-1070 may represent a valuable novel therapeutic intervention for acute sickle cell crises that should be further evaluated in a clinical trial. PMID:20508165

Compliance with the prescribed occlusion treatment for amblyopia.

PubMed

Vagge, Aldo; Nelson, Leonard B

2017-09-01

The present review article is an update on the current evidence about compliance to the prescribed occlusion treatment for amblyopia. In particular, the authors focus on the predictors and causes of noncompliance and possible interventions to increase it. Compliance with prescribed occlusion treatment is often challenging. Reported rates of compliance range widely from 49% to 87%. Objective monitoring of occlusion has opened up new research opportunities and allow the design of effective therapeutic regimens. Also, predictors and causes of noncompliance have been investigated and their knowledge may help the clinician to improved compliance with prescribed occlusion treatment for amblyopia. Although many of the studies assessing the effectiveness of interventions to increase compliance to patching treatment for amblyopia have many limitations, evidences support that use of educational supports, parents, and patient understanding on the importance of patching and written information should be considered to increase compliance with patching.

Noninvasive measurement of central venous pressure

NASA Technical Reports Server (NTRS)

Webster, J. G.; Mastenbrook, S. M., Jr.

1972-01-01

A technique for the noninvasive measurement of CVP in man was developed. The method involves monitoring venous velocity at a point in the periphery with a transcutaneous Doppler ultrasonic velocity meter while the patient performs a forced expiratory maneuver. The idea is the CVP is related to the value of pressure measured at the mouth which just stops the flow in the vein. Two improvements were made over the original procedure. First, the site of venous velocity measurement was shifted from a vein at the antecubital fossa (elbow) to the right external jugular vein in the neck. This allows for sensing more readily events occurring in the central veins. Secondly, and perhaps most significantly, a procedure for obtaining a curve of relative mean venous velocity vs mouth pressure was developed.

Automated vision occlusion-timing instrument for perception-action research.

PubMed

Brenton, John; Müller, Sean; Rhodes, Robbie; Finch, Brad

2018-02-01

Vision occlusion spectacles are a highly valuable instrument for visual-perception-action research in a variety of disciplines. In sports, occlusion spectacles have enabled invaluable knowledge to be obtained about the superior capability of experts to use visual information to guide actions within in-situ settings. Triggering the spectacles to occlude a performer's vision at a precise time in an opponent's action or object flight has been problematic, due to experimenter error in using a manual buttonpress approach. This article describes a new laser curtain wireless trigger for vision occlusion spectacles that is portable and fast in terms of its transmission time. The laser curtain can be positioned in a variety of orientations to accept a motion trigger, such as a cricket bowler's arm that distorts the lasers, which then activates a wireless signal for the occlusion spectacles to change from transparent to opaque, which occurs in only 8 ms. Results are reported from calculations done in an electronics laboratory, as well as from tests in a performance laboratory with a cricket bowler and a baseball pitcher, which verified this short time delay before vision occlusion. In addition, our results show that occlusion consistently occurred when it was intended-that is, near ball release and during mid-ball-flight. Only 8% of the collected data trials were unusable. The laser curtain improves upon the limitations of existing vision occlusion spectacle triggers, indicating that it is a valuable instrument for perception-action research in a variety of disciplines.

Virtual occlusal definition for orthognathic surgery.

PubMed

Liu, X J; Li, Q Q; Zhang, Z; Li, T T; Xie, Z; Zhang, Y

2016-03-01

Computer-assisted surgical simulation is being used increasingly in orthognathic surgery. However, occlusal definition is still undertaken using model surgery with subsequent digitization via surface scanning or cone beam computed tomography. A software tool has been developed and a workflow set up in order to achieve a virtual occlusal definition. The results of a validation study carried out on 60 models of normal occlusion are presented. Inter- and intra-user correlation tests were used to investigate the reproducibility of the manual setting point procedure. The errors between the virtually set positions (test) and the digitized manually set positions (gold standard) were compared. The consistency in virtual set positions performed by three individual users was investigated by one way analysis of variance test. Inter- and intra-observer correlation coefficients for manual setting points were all greater than 0.95. Overall, the median error between the test and the gold standard positions was 1.06mm. Errors did not differ among teeth (F=0.371, P>0.05). The errors were not significantly different from 1mm (P>0.05). There were no significant differences in the errors made by the three independent users (P>0.05). In conclusion, this workflow for virtual occlusal definition was found to be reliable and accurate. Copyright © 2015 International Association of Oral and Maxillofacial Surgeons. Published by Elsevier Ltd. All rights reserved.

[The unnecessary application of central venous catheterization in surgical patients].

PubMed

Uemura, Keiko; Inoue, Satoki; Kawaguchi, Masahiko

2018-04-06

Perioperative physicians occasionally encounter situations where central venous catheters placed preoperatively turn out to be unnecessary. The purpose of this retrospective study is to identify the unnecessary application of central venous catheter placement and determine the factors associated with the unnecessary application of central venous catheter placement. Using data from institutional perioperative central venous catheter surveillance, we analysed data from 1,141 patients who underwent central venous catheter placement. We reviewed the central venous catheter registry and medical charts and allocated registered patients into those with the proper or with unnecessary application of central venous catheter according to standard indications. Multivariate analysis was used to identify factors associated with the unnecessary application of central venous catheter placement. In 107 patients, representing 9.38% of the overall population, we identified the unnecessary application of central venous catheter placement. Multivariate analysis identified emergencies at night or on holidays (odds ratio [OR] 2.109, 95% confidence interval [95% CI] 1.021-4.359), low surgical risk (OR=1.729, 95% CI 1.038-2.881), short duration of anesthesia (OR=0.961/10min increase, 95% CI 0.945-0.979), and postoperative care outside of the intensive care unit (OR=2.197, 95% CI 1.402-3.441) all to be independently associated with the unnecessary application of catheterization. Complications related to central venous catheter placement when the procedure consequently turned out to be unnecessary were frequently observed (9/107) compared with when the procedure was necessary (40/1034) (p=0.032, OR=2.282, 95% CI 1.076-4.842). However, the subsequent multivariate logistic model did not hold this significant difference (p=0.0536, OR=2.115, 95% CI 0.988-4.526). More careful consideration for the application of central venous catheter is required in cases of emergency surgery at night or on

Extravasal occlusion of large vessels with titanic clips: efficiency, indications, and contraindications.

PubMed

Vasilenko, Yu V; Kim, A I; Kotov, S A

2002-11-01

The mechanism of extravasal occlusion of blood vessels with titanic clips "Atrauclip" and "Ligaclip extra" was studied in order to reveal indications and contraindications to their use. Occlusion with the clips of both types was ineffective in vessels with a diameter of >7.0 mm. Arteritis or the presence of an intravascular occlusion facility in the vessel were also the contraindications for clip occlusion. In overcases the procedure of occlusion with titanic clips was efficient and atraumatic.

Impact of Tissue Factor Localization on Blood Clot Structure and Resistance under Venous Shear.

PubMed

Govindarajan, Vijay; Zhu, Shu; Li, Ruizhi; Lu, Yichen; Diamond, Scott L; Reifman, Jaques; Mitrophanov, Alexander Y

2018-02-27

The structure and growth of a blood clot depend on the localization of tissue factor (TF), which can trigger clotting during the hemostatic process or promote thrombosis when exposed to blood under pathological conditions. We sought to understand how the growth, structure, and mechanical properties of clots under flow are shaped by the simultaneously varying TF surface density and its exposure area. We used an eight-channel microfluidic device equipped with a 20- or 100-μm-long collagen surface patterned with lipidated TF of surface densities ∼0.1 and ∼2 molecules/μm 2 . Human whole blood was perfused at venous shear, and clot growth was continually measured. Using our recently developed computational model of clot formation, we performed simulations to gain insights into the clot's structure and its resistance to blood flow. An increase in TF exposure area resulted not only in accelerated bulk platelet, thrombin, and fibrin accumulation, but also in increased height of the platelet mass and increased clot resistance to flow. Moreover, increasing the TF surface density or exposure area enhanced platelet deposition by approximately twofold, and thrombin and fibrin generation by greater than threefold, thereby increasing both clot size and its viscous resistance. Finally, TF effects on blood flow occlusion were more pronounced for the longer thrombogenic surface than for the shorter one. Our results suggest that TF surface density and its exposure area can independently enhance both the clot's occlusivity and its resistance to blood flow. These findings provide, to our knowledge, new insights into how TF affects thrombus growth in time and space under flow. Copyright © 2018 Biophysical Society. All rights reserved.

Preoperative evaluation of venous systems with 3-dimensional contrast-enhanced magnetic resonance venography in brain tumors: comparison with time-of-flight magnetic resonance venography and digital subtraction angiography.

PubMed

Lee, Jong-Myung; Jung, Shin; Moon, Kyung-Sub; Seo, Jeong-Jin; Kim, In-Young; Jung, Tae-Young; Lee, Jung-Kil; Kang, Sam-Suk

2005-08-01

Recent developments in magnetic resonance (MR) technology now enable the use of MR venography, providing 3-dimensional (3D) images of intracranial venous structures. The purpose of this study was to assess the usefulness of 3D contrast-enhanced MR venography (CE MRV) in the evaluation of intracranial venous system for surgical planning of brain tumors. Forty patients underwent 3D CE MRV, as well as 25 patients, 2-dimensional (2D) time-of-flight (TOF) MR venography in axial and sagittal planes; and 10 patients, digital subtraction angiography. We determined the number of visualized sinuses and cortical veins. Degree of visualization of the intracranial venous system on 3D CE MRV was compared with that of 2D TOF MR venography and digital subtraction angiography as a standard. We also assessed the value of 3D CE MRV in the investigation of sinus occlusion or localization of cortical draining veins preoperatively. Superficial cortical veins and the dural sinus were better visualized on 3D CE MRV than on 2D TOF MR venography. Both MR venographic techniques visualized superior sagittal sinus, lateral sinus, sigmoid sinus, straight sinus, and internal cerebral vein and provided more detailed information by showing obstructed sinuses in brain tumors. Only 3D CE MRV showed superficial cortical draining veins. However, it was difficult to accurately evaluate the presence of cortical collateral venous drainage. Although we do not yet advocate MR venography to replace conventional angiography as the imaging standard for brain tumors, 3D CE MRV can be regarded as a valuable diagnostic method just in evaluating the status of major sinuses and localization of the cortical draining veins.

Mechanism of vaso-occlusion in sickle cell anemia

NASA Astrophysics Data System (ADS)

Lei, Huan; Karniadakis, George

2012-11-01

Vaso-occlusion crisis is one of the key hallmark of sickle cell anemia. While early studies suggested that the crisis is caused by blockage of a single elongated cell, recent experimental investigations indicate that vaso-occlusion is a complex process triggered by adhesive interactions among different cell groups in multiple stages. Based on dissipative particle dynamics, a multi-scale model for the sickle red blood cells (SS-RBCs), accounting for diversity in both shapes and cell rigidities, is developed to investigate the mechanism of vaso-occlusion crisis. Using this model, the adhesive dynamics of single SS-RBC was investigated in arterioles. Simulation results indicate that the different cell groups (deformable SS2 RBCs, rigid SS4 RBCs, leukocytes, etc.) exhibit heterogeneous adhesive behavior due to the different cell morphologies and membrane rigidities. We further simulate the tube flow of SS-RBC suspensions with different cell fractions. The more adhesive SS2 cells interact with the vascular endothelium and further trap rigid SS4 cells, resulting in vaso-occlusion in vessels less than 15 μm . Under inflammation, adherent leukocytes may also trap SS4 cells, resulting in vaso-occlusion in even larger vessels. This work was supported by the NSF grant CBET-0852948 and the NIH grant R01HL094270.

Occlusal tooth wear in Chinese adults with shortened dental arches.

PubMed

Zhang, Q; Witter, D J; Bronkhorst, E M; Bartlett, D W; Creugers, N H J

2014-02-01

To assess associations between occlusal tooth wear and shortened dental arches (SDA) in Chinese 40 years and older subjects. From a sample of 1462 urban and rural adults, those presenting with SDA (n = 150) were compared with a control group of 65 randomly selected subjects with complete dentitions (CDA). Occlusal wear was assessed using a modified Smith and Knight index - the occlusal tooth wear index (OWTI) - and analysed using multivariate (logistic) regression. There was no significant effect from SDA on severe occlusal wear (OTWI score 3 or 4: OR = 2.016; 95% CI = 0.960-4.231; P = 0.064). Higher age was associated with severe occlusal wear (P values ≤0.007) and with higher mean OTWI scores; urban had less often severe occlusal wear than rural residents (OR = 0.519; P = 0.008). Higher mean OTWI scores were associated with rural residents, except for anterior teeth. Females had lower mean OTWI score for anterior teeth (effect = -0.153; P = 0.030). Premolars in SDA had higher mean OTWI scores compared with those in CDA (effect = +0.213; P = 0.006). In SDA, more posterior occluding pairs (POPs) were associated with lower mean OTWI sores for anterior teeth (effect: -0.158; P = 0.008) and higher scores for molars (effect: +0.249, P = 0.003). Subjects with SDA or CDA presented comparable occlusal wear, but premolars in SDA tend to have higher probability for having occlusal wear. Fewer numbers of POPs were associated with more wear in anterior teeth. © 2013 John Wiley & Sons Ltd.

Unilateral Loss of Spontaneous Venous Pulsations in an Astronaut

NASA Technical Reports Server (NTRS)

Mader, Thomas H.; Gibson, C. Robert; Lee, Andrew G.; Patel, Nimesh; Hart, Steven; Pettit, Donald R.

2014-01-01

Spontaneous venous pulsations seen on the optic nerve head (optic disc) are presumed to be caused by fluctuations in the pressure gradient between the intraocular and retrolaminar venous systems. The disappearance of previously documented spontaneous venous pulsations is a well-recognized clinical sign usually associated with a rise in intracranial pressure and a concomitant bilateral elevation of pressure in the subarachnoid space surrounding the optic nerves. In this correspondence we report the unilateral loss of spontaneous venous pulsations in an astronaut 5 months into a long duration space flight. We documented a normal lumbar puncture opening pressure 8 days post mission. The spontaneous venous pulsations were also documented to be absent 21 months following return to Earth.. We hypothesize that these changes may have resulted from a chronic unilateral rise in optic nerve sheath pressure caused by a microgravity-induced optic nerve sheath compartment syndrome.

Nonlinear dynamic model for visual object tracking on Grassmann manifolds with partial occlusion handling.

PubMed

Khan, Zulfiqar Hasan; Gu, Irene Yu-Hua

2013-12-01

This paper proposes a novel Bayesian online learning and tracking scheme for video objects on Grassmann manifolds. Although manifold visual object tracking is promising, large and fast nonplanar (or out-of-plane) pose changes and long-term partial occlusions of deformable objects in video remain a challenge that limits the tracking performance. The proposed method tackles these problems with the main novelties on: 1) online estimation of object appearances on Grassmann manifolds; 2) optimal criterion-based occlusion handling for online updating of object appearances; 3) a nonlinear dynamic model for both the appearance basis matrix and its velocity; and 4) Bayesian formulations, separately for the tracking process and the online learning process, that are realized by employing two particle filters: one is on the manifold for generating appearance particles and another on the linear space for generating affine box particles. Tracking and online updating are performed in an alternating fashion to mitigate the tracking drift. Experiments using the proposed tracker on videos captured by a single dynamic/static camera have shown robust tracking performance, particularly for scenarios when target objects contain significant nonplanar pose changes and long-term partial occlusions. Comparisons with eight existing state-of-the-art/most relevant manifold/nonmanifold trackers with evaluations have provided further support to the proposed scheme.

Study of occlusal characteristics of primary dentition and the prevalence of maloclusion in 4 to 6 years old children in India

PubMed Central

Bhayya, Deepak P; Shyagali, Tarulatha R; Dixit, Uma B; Shivaprakash

2012-01-01

Background: To assess the prevalence of malocclusion and to determine the different occlusal characteristics in primary dentition of 4 to 6 years old children in India. Materials and Methods: The target population comprised 4 to 6 years old children attending different nursery, kindergarten and primary schools of Bagalkot city. Stratified cluster random sampling procedure was executed to collect the representative sample. Each subject was assessed for various occlusal characteristics. Results: Occlusal characteristic found were flush terminal plane (52.5%), class I canine relationship (84%), maxillary developmental spaces (35.4%), primate spaces in maxilla (47.6%), mandibular crowding (4.6%), mandibular midline shift (5.6%), anterior multiple tooth crossbite (1.3%), scissors bite (0.6%), anterior open bite (1%), over bite of 0-2 mm (81.6%) and overjet of 0-2 mm (84.5%). The age wise difference for the occlusal characteristics was statistically significant. Conclusions: The data revealed that most of the children had malocclusion. This highlights the importance of identifying children who are in need of orthodontic treatment for dental health or aesthetic reasons. PMID:23559929

Pulmonary veno-occlusive disease and pulmonary capillary hemangiomatosis.

PubMed

Ortiz-Bautista, Carlos; Hernández-González, Ignacio; Escribano-Subías, Pilar

2017-03-22

Pulmonary veno-occlusive disease is a rare cause of pulmonary hypertension which is part, together with pulmonary capillary hemangiomatosis, of the special designation (subgroup 1') within pulmonary hypertension group 1 in the latest classification of the pulmonary hypertension World Symposium. Recent discovery that gene mutations in eukaryotic translation initiation factor 2 alpha kinase 4 (EIF2AK4) are responsible for inherited forms of pulmonary veno-occlusive disease has changed the role of genetic testing, acquiring relevant importance in the diagnosis of these patients. Despite the advances in genetic, cellular and molecular basis knowledge in the last decade, pulmonary veno-occlusive disease remains as a rare aetiology of pulmonary hypertension without any effective medical treatment approved and poor outcomes. This document aims to review the advances occurred in the understanding of pulmonary veno-occlusive disease in the last years. Copyright © 2016 Elsevier España, S.L.U. All rights reserved.

Venous thrombosis after hallux valgus surgery.

PubMed

Radl, Roman; Kastner, Norbert; Aigner, Christian; Portugaller, Horst; Schreyer, Herbert; Windhager, Reinhard

2003-07-01

Although surgery for the treatment of hallux valgus is frequently performed, the exact rate of deep vein thrombosis following this procedure is unknown. We performed a single-center, prospective, phlebographically controlled study to quantify the rate of venous thrombosis following operative correction of hallux valgus. Consecutive patients undergoing chevron bunionectomy for correction of hallux valgus deformity were enrolled in the study. Patients with clinical or hematological risk factors for venous thrombosis were excluded. One hundred patients with a mean age of 48.9 years were operated on and did not receive medical prophylaxis against thrombosis. All patients were assessed with phlebography at a mean of twenty-nine days postoperatively. Venous thrombosis was found in four patients (4%). The mean age of these patients (and standard deviation) was 61.7 +/- 6.1 years compared with a mean age of 48.4 +/- 13.9 years for the patients in whom thrombosis did not develop (p = 0.034). Patients are at a low risk for venous thrombosis following surgical treatment of hallux valgus. The need for prophylaxis against thrombosis should be calculated individually for each patient according to his or her known level of risk. Routine medical prophylaxis against thrombosis might be justified for patients over the age of sixty years.

A change in humidification system can eliminate endotracheal tube occlusion.

PubMed

Doyle, Alex; Joshi, Manasi; Frank, Peter; Craven, Thomas; Moondi, Parvez; Young, Peter

2011-12-01

Inadequate airway humidification can result in endotracheal tube occlusion. There is evidence that heat and moisture exchangers (HMEs) are more prone to endotracheal tube occlusion than heated humidifiers (HHs) that contain a heated wire circuit. We aimed to compare the incidence of endotracheal tube occlusion while introducing a new dual-heated wire circuit HH in place of an established hydrophobic HME. This was a prospective observational study. All patients who required intubation were included in our analysis. Univariate statistical analysis was performed using a Fisher exact test. P < .05 was considered statistically significant. There were 158 patients in the HME group and 88 patients in the HH group. The incidence of endotracheal tube occlusion was 5.7% in the HME group and 0% in the HH group. Statistical analysis revealed a significant difference between the 2 groups (P = .02). In light of this finding, we changed our practice to provide humidification exclusively by HH. In the subsequent 18-month period, there were no further episodes of endotracheal tube occlusion. Our study demonstrates that there is a significant increase in the incidence of endotracheal tube occlusion when using a hydrophobic HME compared with an HH and that using a dual-heated wire circuit HH can eliminate endotracheal tube occlusion. Copyright © 2011 Elsevier Inc. All rights reserved.

Occlusal accommodation and mouthguards for prevention of orofacial trauma.

PubMed

Geary, Julian Lindsay; Clifford, Thomas Joseph; Kinirons, Martin James

2009-01-01

The aim of this study was to investigate the effect of two types of occlusal accommodation on the arch separation in centric and eccentric arch positions and to assess the opposing tooth contacts in professionally made, thermoformed sports mouthguards. Maxillary and mandibular alginate impressions, a wax interocclusal record of centric occlusion together with maxillary/condylar face-bow registrations, were recorded clinically for 10 undergraduate dental students who are sports activist volunteers of the School of Medicine and Dentistry, Queen's University Belfast. Two ethylene vinyl acetate thermoformed maxillary mouthguards were made for each player (N = 20) using a standardised procedure. Ten mouthguards served both as the control (i.e. the non-accommodated) group and also the accommodated, occlusally 'imprinted' group. The other 10 mouthguards served as the accommodated, occlusally 'ground' group. Casts were articulated, each non-accommodated and accommodated mouthguard was seated and the extent of the interocclusal opening was recorded in all three arch relationships. The number of mouthguard and mandibular tooth contacts were also recorded in each position. The increased vertical occlusal dimension that was found in the presence of non-accommodated mouthguards equated to the full-sheet thickness of the material that was used to form the mouthguards. Only mouthguards accommodated by grinding retained high levels of occlusal contact in all arch relationships that were tested. Within the limitations of this study, the modification of the occlusal surface made by flat grinding reduced the arch separation in eccentric movements and increased the opposing tooth contacts in custom-made mouthguards. This may contribute to increased comfort, compliance and the protective effect of these appliances thus resulting in a reduction of injuries to the teeth, arches and soft tissues.

Partial anomalous pulmonary venous return in Turner syndrome.

PubMed

van den Hoven, Allard T; Chelu, Raluca G; Duijnhouwer, Anthonie L; Demulier, Laurent; Devos, Daniel; Nieman, Koen; Witsenburg, Maarten; van den Bosch, Annemien E; Loeys, Bart L; van Hagen, Iris M; Roos-Hesselink, Jolien W

2017-10-01

The aim of this study is to describe the prevalence, anatomy, associations and clinical impact of partial anomalous pulmonary venous return in patients with Turner syndrome. All Turner patients who presented at our Turner clinic, between January 2007 and October 2015 were included in this study and underwent ECG, echocardiography and advanced imaging such as cardiac magnetic resonance or computed tomography as part of their regular clinical workup. All imaging was re-evaluated and detailed anatomy was described. Partial anomalous pulmonary venous return was diagnosed in 24 (25%) out of 96 Turner patients included and 14 (58%) of these 24 partial anomalous pulmonary venous return had not been reported previously. Right atrial or ventricular dilatation was present in 11 (46%) of 24 partial anomalous pulmonary venous return patients. When studied with advanced imaging modalities and looked for with specific attention, PAPVR is found in 1 out of 4 Turner patients. Half of these patients had right atrial and/or ventricular dilatation. Evaluation of pulmonary venous return should be included in the standard protocol in all Turner patients. Copyright © 2017. Published by Elsevier B.V.

High dose urokinase for restoration of patency of occluded permanent central venous catheters in hemodialysis patients.

PubMed

Shavit, L; Lifschitz, M; Plaksin, J; Grenader, T; Slotki, I

2010-10-01

Catheter thrombosis is common and results in inadequate dialysis treatment and, frequently, in catheter loss. Since dialysis treatment runs on a strict schedule, occluded catheters need to be restored in a timely and cost effective manner. We present a new shortened protocol of urokinase infusion that allows hemodialysis to be performed within 90 minutes. To chronic hemodialysis patients, who developed complete catheter occlusion, urokinase was infused simultaneously through both lumens of the catheter (125,000 units to each lumen) over 90 minutes. Technical success was defined as restoring blood pump speed to at least 250 ml/min. We determined the average time from catheter placement to first clot event (primary patency PP), recurrent clot event after urokinase treatment (secondary patency SP), catheter salvage rate and cause for removal. 37 catheters developed total thrombosis and urokinase was used to restore patency one or more times (total 47 treatments). Catheter salvage rate was 97 %. The average time of PP was 152 ± 56 days (7 - 784 days). Nine patients (30%) developed recurrent occlusion and the average time of SP was 64 ± 34 days (2 - 364 days). One catheter was removed because of dysfunction due to thrombosis. Other catheters were removed due to infection, fistula maturation or fell out spontaneously. Hemodialysis was performed immediately after treatment with blood speed of 250 ml/min in all patients. Our protocol is highly effective, short, and allows to restore patency of totally occluded central venous catheters with minimal disruption of the dialysis session.

Occlusion-amblyopia following high dose oral levodopa combined with part time patching

PubMed Central

Kothari, Mihir

2014-01-01

Part time occlusion therapy is not reported to cause occlusion (reverse) amblyopia. However, when combined with high dose oral levodopa, an increase in the plasticity of the visual cortex can lead to occlusion amblyopia. In this case report, we describe a six year old child who developed occlusion amblyopia following part time patching combined with oral levodopa. PMID:23571255

Occlusion-amblyopia following high dose oral levodopa combined with part time patching.

PubMed

Kothari, Mihir

2014-12-01

Part time occlusion therapy is not reported to cause occlusion (reverse) amblyopia. However, when combined with high dose oral levodopa, an increase in the plasticity of the visual cortex can lead to occlusion amblyopia. In this case report, we describe a six year old child who developed occlusion amblyopia following part time patching combined with oral levodopa.

Pharmacological prevention of rocuronium-induced injection pain or withdrawal movements: a meta-analysis.

PubMed

Kwak, Hyun Jeong; Kim, Ji Young; Kim, Yong Beom; Min, Sang Kee; Moon, Bong Ki; Kim, Jong Yeop

2013-10-01

Rocuronium is reported to be associated with injection pain or withdrawal movement (IPWM). This meta-analysis assessed the efficacy of different pharmacological treatments used to decrease the incidence of the rocuronium-induced IPWM. We searched the Cochrane Library, Embase and PubMed for randomized controlled trials comparing a pharmacological drug with a placebo to prevent the rocuronium-induced IPWM and found 37 studies with 5,595 patients. Overall incidence of rocuronium-induced IPWM was 74%. Pretreatment with opioids [risk ratio (RR) 0.16; 95% confidence interval (95% CI) 0.09-0.29], lidocaine (0.47; 0.35-0.64), and ketamine (0.41; 0.22-0.77) were effective in decreasing IPWM. Lidocaine pretreatment with venous occlusion (0.40; 0.32-0.49) and opioids pretreatment with venous occlusion (0.77; 0.61-0.96) were also effective. Mixing sodium bicarbonate (NaHCO3) with rocuronium (0.15; 0.06-0.34) was also efficacious in reducing IPWM. Indirect comparison shows that the RR of NaHCO3 admixture and pretreatment with opioids were lower than that of the other four interventions (pretreatments of ketamine or lidocaine, and lidocaine or opioids with venous occlusion). This meta-analysis suggests that opioids, lidocaine, ketamine, and NaHCO3 are effective in decreasing rocuronium-induced IPWM. Considering the efficacy and convenience, pretreatment with opioids without venous occlusion is recommended for reducing rocuronium-induced IPWM.

Venous drainage of the face.

PubMed

Onishi, S; Imanishi, N; Yoshimura, Y; Inoue, Y; Sakamoto, Y; Chang, H; Okumoto, T

2017-04-01

The venous anatomy of the face was examined in 12 fresh cadavers. Venograms and arteriovenograms were obtained after the injection of contrast medium. In 8 of the 12 cadavers, a large loop was formed by the facial vein, the supratrochlear vein, and the superficial temporal vein, which became the main trunk vein of the face. In 4 of the 12 cadavers, the superior lateral limb of the loop vein was less well developed. The loop vein generally did not accompany the arteries of the face. Cutaneous branches of the loop vein formed a polygonal venous network in the skin, while communicating branches ran toward deep veins. These findings suggest that blood from the dermis of the face is collected by the polygonal venous network and enters the loop vein through the cutaneous branches, after which blood flows away from the face through the superficial temporal vein, the facial vein, and the communicating branches and enters the deep veins. Copyright © 2016 British Association of Plastic, Reconstructive and Aesthetic Surgeons. Published by Elsevier Ltd. All rights reserved.

A survey of current practice of vascular surgeons in venous disease management.

PubMed

Bush, Ruth L; Gloviczki, Peter

2013-01-01

Acute venous thromboembolism and chronic venous diseases are common conditions that affect a large proportion of the United States population. The diagnosis of venous disease has improved, and the treatment options have rapidly evolved over the past decade. To date, it is unclear to what extent vascular surgeons have become involved in the modern management of venous disorders. This survey was undertaken to explore the current interest and practice of vascular surgeons in the contemporary care of venous disease. A survey was administered via a web-based platform to active and candidate members of the Society for Vascular Surgery (SVS). The survey included 30 questions investigating the characteristics of venous surgeons and scope of venous practice. Open-ended questions were also included for commentary. A total of 1879 surveys were sent to SVS members nationwide, and 385 members participated (response rate of 20.5%). The participants were mostly men (89.6%) with 37.7% practicing in an academic setting and 59.2% in private practice. The respondents treated superficial veins (92.9%) and deep veins (85.8%) in clinical practice, with 89.9% having their own vascular laboratory. A wide spectrum of interventions for superficial (91.9%), deep (85.8%), and perforator veins (52.7% endovenous, 19.4% subfascial endoscopic perforator surgery) are being performed by respondents. Only 26.2% had learned endovenous thermal ablation in their training program; however, over 96% of those performing venous interventions utilized this technique. Overall, the majority (85.5%) devoted 50% or less of practice to venous disorders. Respondents indicated that limitations to expansion of vein practices mainly involved challenges with third party payers, local competition, and existing large volumes of arterial interventions needing to be performed. Despite the widespread incorporation of venous disease into current vascular practices, 66.1% are not members of the American Venous Forum (AVF

[Superficial venous thrombosis. A state of art].

PubMed

Sándor, Tamás

2017-01-01

For a long time superficial thrombophlebitis has been thought to be a rather benign condition. Recently, when duplex ultrasound technique is used for the diagnosis more and more often, the disease is proved to be more dangerous than anticipated. Thrombosis propagates to the deep veins in 6-44% and pulmonary embolism was observed on the patients in 1,5-33%. We can calculate venous thromboembolic complications on every fourth patient. Diagnosis is clinical, but duplex ultrasound examination is mandatory, for estimation of the thrombus extent, for exclusion of the deep venous thrombosis and for follow up. Both legs should be checked with ultrasound, because simultaneous deep venous thrombosis can develop on the contralateral limb. Two different forms can be distinguished: superficial venous thrombosis with, or without varicose veins. In cases of spontaneous, non varicous form, especially when the process is migrating or recurrent, a careful clinical examination is necessery for exclusion of malignant diseases and thrombophilia. The treatment options are summarised on the basis of recent international consensus statements. The American and German guidelines are similar. Compression and mobilisation are cornerstones of the therapy. For a short segment thrombosis non steroidal antiinflammatory drugs are effective. For longer segments low molecular-weight heparins are preferred. Information on the effect of the novel oral anticoagulants for the therapy is lacking but they may appear to be effective in the future for this indication. When thrombus is close to the sapheno-femoral or sapheno-popliteal junction crossectomy (high ligation), or low molecular-weight heparin in therapeutic doses are indicated. The term superficial thrombophlebitis should be discouraged, because inflammation and infection is not the primary pathology. It should be called correctly superficial venous thrombosis in order to avoid the unnecessary administration of antibiotics and the misconception

Central Vein Dilatation Prior to Concomitant Port Implantation

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

Krombach, Gabriele A., E-mail: krombach@rad.rwth-aachen.de; Plumhans, Cedric; Goerg, Fabian

2010-04-15

Implantation of subcutaneous port systems is routinely performed in patients requiring repeated long-term infusion therapy. Ultrasound- and fluoroscopy-guided implantation under local anesthesia is broadly established in interventional radiology and has decreased the rate of complications compared to the surgical approach. In addition, interventional radiology offers the unique possibility of simultaneous management of venous occlusion. We present a technique for recanalization of central venous occlusion and angioplasty combined with port placement in a single intervention which we performed in two patients. Surgical port placement was impossible owing to occlusion of the superior vena cava following placement of a cardiac pacemaker andmore » occlusion of multiple central veins due to paraneoplastic coagulopathy, respectively. In both cases the affected vessel segments were dilated with balloon catheters and the port systems were placed thereafter. After successful dilatation, the venous access was secured with a 25-cm-long, 8-Fr introducer sheath, a subcutaneous pocket prepared, and the port catheter tunneled to the venipuncture site. The port catheter was introduced through the sheath with the proximal end connected to a 5-Fr catheter. This catheter was pulled through the tunnel in order to preserve the tunnel and, at the same time, allow safe removal of the long sheath over the wire. The port system functioned well in both cases. The combination of recanalization and port placement in a single intervention is a straightforward alternative for patients with central venous occlusion that can only be offered by interventional radiology.« less

Relationships between duplex findings and quality of life in long-term follow-up of patients treated for chronic venous disease.

PubMed

Huang, Ying; Gloviczki, Peter

2016-03-01

Relationships between duplex findings and data on health-related quality of life (QoL) to assess long-term results of treatment of varicose veins and chronic venous insufficiency (CVI) are not well known. The goal of this review was to correlate duplex findings and QoL assessments in clinical studies with long-term follow-up. A review of the English language literature on PUBMED revealed 17 clinical studies, including 9 randomized controlled trials (RCTs), 6 prospective, and 2 retrospective studies that included patients with at least 5-year follow-up after endovenous laser ablation (EVLA), radiofrequency ablation (RFA), ultrasound-guided foam sclerotherapy (UGFS), and traditional superficial venous surgery. At 5 years, great saphenous vein (GSV) occlusion rate on duplex ultrasound ranged from 66% to 82% for EVLA, from 62% to 92% for RFA, from 41% to 58% for UGFS and from 54% to 85% for surgery. Freedom from GSV reflux rates were 82% and 84%, respectively for EVLA and surgery, and ranged between 84% and 95% for RFA. Significant improvements were observed in several domains of generic QoL and in most domains of venous disease-specific QoL, irrespective of the treatment. In at least one RCT, CIVIQ scores correlated well with abnormal duplex findings in patients who underwent treatment with UGFS. In another RCT, long-term AVVQ was significantly better after surgery as compared with UGFS similar to results of duplex findings. Analysis of the available literature confirmed that all four techniques were effective in the abolishment of reflux or obliteration of the GSV. Moreover, well-designed RCTs with large sample size are needed to produce robust long-term data on clinical outcome after treatment of varicose veins and CVI and to better understand the relationships between duplex-derived data and QoL assessments. © The Author(s) 2016.

Combined Central Retinal Vein and Branch Retinal Artery Occlusion Post Intense Physical Activity.

PubMed

Coca, Mircea; Tecle, Nahom; Amde, Wendewessen; Mehta, Ankur

2017-08-23

We report a case of combined central retinal vein occlusion and branch retinal artery occlusion. A previously healthy 47-year-old male presented with decreased vision in the right eye after completing a half marathon. A fundus exam and retinal imaging revealed a combined central retinal vein and branch retinal artery occlusion. In the present report, we review the literature and discuss the possible mechanisms behind combined retinal vessel occlusions. To our knowledge, this is the first reported case of combined central retinal vein occlusion and branch retinal artery occlusion following intense exercise.

Combined Central Retinal Vein and Branch Retinal Artery Occlusion Post Intense Physical Activity

PubMed Central

Tecle, Nahom; Amde, Wendewessen; Mehta, Ankur

2017-01-01

We report a case of combined central retinal vein occlusion and branch retinal artery occlusion. A previously healthy 47-year-old male presented with decreased vision in the right eye after completing a half marathon. A fundus exam and retinal imaging revealed a combined central retinal vein and branch retinal artery occlusion. In the present report, we review the literature and discuss the possible mechanisms behind combined retinal vessel occlusions. To our knowledge, this is the first reported case of combined central retinal vein occlusion and branch retinal artery occlusion following intense exercise. PMID:29067224

[Application of temporary balloon occlusion of the abdominal aorta in the treatment of complete placenta previa complicated with placenta accreta].

PubMed

Cui, S H; Zhi, Y X; Zhang, K; Zhang, L D; Shen, L N; Gao, Y N

2016-09-25

Objective: To investigate the value of temporary balloon occlusion of the abdominal aorta in the treatment of complete placenta previa with placenta accreta. Methods: From January 2015 to February 2016, 24 cases of complete placenta previa with placenta accreta were treated with temporary balloon occlusion of the abdominal aorta(the study group)before cesarean, and 24 cases of complete placenta previa with placenta accreta did not receive balloon occlusion(the control group). The operation time, intraoperative blood loss, intraoperative blood transfusion volume, the perioperative hemoglobin level, the hysterectomy rate and the related complications were compared retrospectively.Also, the hospitalization time, the blood coagulation parameters after operation, including activated partial thromboplastin time(APTT), fibrinogen(FIB), D-Dimer and reperfusion injury parameters including creatine phosphokinase(CK), creatine phosphokinase isoenzyme(CK-MB), lactate dehydrogenase(LDH)and serum creatinine were compared between the 2 groups. Results: The blood loss[750 ml(400- 2 000 ml)vs 2 000 ml(1 500- 2 375 ml); Z =-3.214, P =0.001]and blood transfusion volume[200 ml(0-800 ml)vs 800 ml(0-1 200 ml); Z =- 2.173, P =0.030]in the study group were lower than in the control group. The hemoglobin difference between before and after operation in the study group was lower than the control group[(12.8±13.4)g/L vs(22.9±20.1)g/L; t =-2.041, P =0.047]. In the study group, there were still bleeding in 13 cases after releasing the balloon, 5 of them received uterine artery embolization, 5 cases received uterine artery ligation, and 3 cases received uterine packing. One case had venous thrombosis in the right lower limb. Two cases(8%,2/24)in the control group had hysterectomy, while none in the study group, there was no statistical significance( P = 0.489). Conclusions: Temporary balloon occlusion of the abdominal aorta can effectively reduce blood loss and blood transfusion in the

Manual lymphatic drainage in chronic venous disease: a duplex ultrasound study.

PubMed

Dos Santos Crisóstomo, Rute Sofia; Candeias, Miguel Sandu; Ribeiro, Ana Margarida Martins; da Luz Belo Martins, Catarina; Armada-da-Silva, Paulo As

2014-12-01

To compare the effect of call-up and reabsorption maneuvers of manual lymphatic drainage on blood flow in femoral vein and great saphenous vein in patients with chronic venous disease and healthy controls. Forty-one subjects participated in this study (mean age: 42.68(15.23)), 23 with chronic venous disease (chronic venous disease group) with clinical classification C1-5 of clinical-etiological-anatomical-pathological (CEAP) and 18 healthy subjects (control group). Call-up and reabsorption maneuvers were randomly applied in the medial aspect of the thigh. The cross-sectional areas, as well as the peak and the mean blood flow velocity at femoral vein and great saphenous vein, were assessed by Duplex ultrasound at the baseline and during maneuvers. The venous flow volume changes were calculated. The venous flow volume in femoral vein and great saphenous vein increased during both manual lymphatic drainage maneuvers and in both groups (P < 0.05). The two maneuvers had a similar effect on femoral vein and great saphenous vein hemodynamics, and in both the chronic venous disease and control groups. As a result of the call-up maneuver, the flow volume augmentations, as a result of call-up maneuver, decreased with the severity of chronic venous disease in those patients measured by the clinical classification of CEAP (r = -0.64; P = 0.03). Manual lymphatic drainage increases the venous blood flow in the lower extremity with a magnitude that is independent from the specific maneuver employed or the presence of chronic venous disease. Therefore, manual lymphatic drainage may be an alternative strategy for the treatment and prevention of venous stasis complications in chronic venous disease. © The Author(s) 2013 Reprints and permissions: sagepub.co.uk/journalsPermissions.nav.

Extrinsic cerebral venous sinus obstruction resulting in intracranial hypertension

PubMed Central

Goldsmith, P; Burn, D; Coulthard, A; Jenkins, A

1999-01-01

We report the case of a 70-year-old man reporting with headache and visual disturbances who was being treated for prostate cancer. Investigations showed him to have intracranial hypertension caused by venous sinus obstruction. Patients with metastatic disease and raised intracranial pressure in the absence of focal signs should be considered as possible cases of venous outflow obstruction.


Keywords: intracranial hypertension; venous sinus thrombosis; malignancy PMID:10616691

Usefulness of high-speed rotational coronary venous angiography during cardiac resynchronization therapy.

PubMed

Blendea, Dan; Mansour, Moussa; Shah, Ravi V; Chung, Jeffrey; Nandigam, Veena; Heist, E Kevin; Mela, Theofanie; Reddy, Vivek Y; Manzke, Robert; McPherson, Craig A; Ruskin, Jeremy N; Singh, Jagmeet P

2007-11-15

Standard coronary venous angiography (SCVA) provides a static, fixed projection of the coronary venous (CV) tree. High-speed rotational coronary venous angiography (RCVA) is a novel method of mapping CV anatomy using dynamic, multiangle visualization. The purpose of this study was to assess the value of RCVA during cardiac resynchronization therapy. Digitally acquired rotational CV angiograms from 49 patients (mean age 69 +/- 11 years) who underwent left ventricular lead implantation were analyzed. RCVA, which uses rapid isocentric rotation over a 110 degrees arc, acquiring 120 frames/angiogram, was compared with SCVA, defined as 2 static orthogonal views: right anterior oblique 45 degrees and left anterior oblique 45 degrees . RCVA demonstrated that the posterior vein-to-coronary sinus (CS) angle and the left marginal vein-to-CS angle were misclassified in 5 and 11 patients, respectively, using SCVA. RCVA identified a greater number of second-order tributaries with diameters >1.5 mm than SCVA. The CV branch selected for lead placement was initially identified in 100% of patients using RCVA but in only 74% of patients using SCVA. RCVA showed that the best angiographic view for visualizing the CS and its tributaries differed significantly among different areas of the CV tree and among patients. The area of the CV tree that showed less variability was the CS ostium, which had a fairly constant relation with the spine in shallow right anterior oblique and left anterior oblique projections. In conclusion, RCVA provided a more precise map of CV anatomy and the spatial relation of venous branches. It allowed the identification of fluoroscopic views that could facilitate cannulation of the CS. The final x-ray view displaying the appropriate CV branch for left ventricular lead implantation was often different from the conventional left anterior oblique and right anterior oblique views. RCVA identified the target branch for lead implantation more often than SCVA.

Pattern of Venous Collateral Development after Splenic Vein Occlusion in an Extended Whipple Procedure (Whipple at the Splenic Artery) and Long-Term Results.

PubMed

Rosado, Ismael Dominguez; Bhalla, Sanjeev; Sanchez, Luis A; Fields, Ryan C; Hawkins, William G; Strasberg, Steven M

2017-03-01

Extended Whipple procedures may require division of the splenic vein (SV). Controversy exists regarding the risk of sequelae of sinistral portal hypertension when the SV is ligated without reimplantation. The aim of this study was to identify postoperative venous collateral patterns and sequelae of SV ligation, as well as long-term results in an extended Whipple procedure. Patients who had an extended Whipple procedure (Whipple at the Splenic Artery or WATSA) were entered in an institutional database. Evaluation of the venous collaterals was performed at least 5 months postoperatively by imaging. Spleen size and platelet counts were measured before and after operation. Fifteen patients were entered from 2009 to 2014. SV was not reconstructed and the IMV-SV junction was always resected. Two collateral routes developed. An inferior route was present 14/15 patients. It connected the residual SV to the SMV via intermediate collateral veins in the omentum and along the colon. A superior route, present in 10/15 patients connected the residual SV to the portal vein via gastric, perigastric, and coronary veins. Gastrointestinal bleeding did not occur. Mean platelet count and spleen size were not affected significantly. Procedures were long, but few severe complications developed. In 12 patients with adenocarcinoma, the median survival has not been reached. Patients who have SV ligation in an extended Whipple are protected against sequelae of sinestral portal hypertension by inferior collateral routes. The omentum and marginal veins of the colon are key links in this pathway.

Comparison of vacuum rise time, vacuum limit accuracy, and occlusion break surge of 3 new phacoemulsification systems.

PubMed

Han, Young Keun; Miller, Kevin M

2009-08-01

To compare vacuum rise time, vacuum limit accuracy, and occlusion break surge of 3 new phacoemulsification machines. Jules Stein Eye Institute and Department of Ophthalmology, David Geffen School of Medicine at UCLA, Los Angeles, California, USA. The vacuum rise time under normal and enhanced aspiration modes, vacuum limit accuracy, and occlusion break surge of the Infiniti Vision System, Stellaris Vision Enhancement System, and WhiteStar Signature Phacoemulsification System were tested. Vacuum rise time and limit accuracy were measured at limit settings of 400 mm Hg and 600 mm Hg. Surge area was recorded at vacuum limit settings of 200 mm Hg, 300 mm Hg, 400 mm Hg, and 500 mm Hg. The Infiniti had the fastest vacuum rise times under normal and enhanced aspiration modes. At 4 seconds, the vacuum limit accuracy was greatest with the Infiniti at the 400 mm Hg limit and the Signature at the 600 mm Hg limit. The Stellaris did not reach either vacuum target. The Infiniti performed better than the other 2 machines during testing of occlusion break surge at all vacuum limit settings above 200 mm Hg. Under controlled laboratory test conditions, the Infiniti had the fastest vacuum rise time, greatest vacuum limit accuracy at 400 mm Hg, and least occlusion break surge. These results can be explained by the lower compliance of the Infiniti system.

Lymphatic Leak Complicating Central Venous Catheter Insertion

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

Barnacle, Alex M., E-mail: alexbarnacle@yahoo.co.uk; Kleidon, Tricia M.

2005-12-15

Many of the risks associated with central venous access are well recognized. We report a case of inadvertent lymphatic disruption during the insertion of a tunneled central venous catheter in a patient with raised left and right atrial pressures and severe pulmonary hypertension, which led to significant hemodynamic instability. To our knowledge, this rare complication is previously unreported.

Improving prediction of recanalization in acute large-vessel occlusive stroke.

PubMed

Vanacker, P; Lambrou, D; Eskandari, A; Maeder, P; Meuli, R; Ntaios, G; Michel, P

2014-06-01

Recanalization in acute ischemic stroke with large-vessel occlusion is a potent indicator of good clinical outcome. To identify easily available clinical and radiologic variables predicting recanalization at various occlusion sites. All consecutive, acute stroke patients from the Acute STroke Registry and Analysis of Lausanne (2003-2011) who had a large-vessel occlusion on computed tomographic angiography (CTA) (< 12 h) were included. Recanalization status was assessed at 24 h (range: 12-48 h) with CTA, magnetic resonance angiography, or ultrasonography. Complete and partial recanalization (corresponding to the modified Treatment in Cerebral Ischemia scale 2-3) were grouped together. Patients were categorized according to occlusion site and treatment modality. Among 439 patients, 51% (224) showed complete or partial recanalization. In multivariate analysis, recanalization of any occlusion site was most strongly associated with endovascular treatment, including bridging therapy (odds ratio [OR] 7.1, 95% confidence interval [CI] 2.2-23.2), and less so with intravenous thrombolysis (OR 1.6, 95% CI 1.0-2.6) and recanalization treatments performed beyond guidelines (OR 2.6, 95% CI 1.2-5.7). Clot location (large vs. intermediate) and tandem pathology (the combination of intracranial occlusion and symptomatic extracranial stenosis) were other variables discriminating between recanalizers and non-recanalizers. For patients with intracranial occlusions, the variables significantly associated with recanalization after 24 h were: baseline National Institutes of Health Stroke Scale (NIHSS) (OR 1.04, 95% CI 1.02-1.1), Alberta Stroke Program Early CT Score (ASPECTS) on initial computed tomography (OR 1.2, 95% CI 1.1-1.3), and an altered level of consciousness (OR 0.2, 95% CI 0.1-0.5). Acute endovascular treatment is the single most important factor promoting recanalization in acute ischemic stroke. The presence of extracranial vessel stenosis or occlusion decreases

Simultaneous Iliac Vein Bovine Pericardial Patch Venoplasty and Creation of PTFE Lower Limb Arteriovenous Fistula Graft for Rescue Vascular Access.

PubMed

Meecham, Lewis; Fisher, Owain; Kirby, George; Evans, Richard; Buxton, Pauline; Legge, Jocelyn; Rajagopalan, Sriram; Asquith, John; Pherwani, Arun

2016-10-01

We present a case of external iliac vein patch venoplasty to accommodate rescue vascular access via a polytetrafluoroethylene loop arteriovenous fistula graft (AVG) for a patient with multiple central venous stenoses. A 35-year-old female with anti-glomerular basement membrane antibody disease required rescue vascular access for hemodialysis. Repeated occlusion and/or thrombosis of long-term central venous access cannulae, to facilitate dialysis, had caused stenosis of brachiocephalic veins: right external iliac vein and occlusion of the left common iliac vein. A previous right brachiobasilic fistula had occluded within 1 year. No other upper limb options for arteriovenous fistula (AVF) were available. A right external iliac vein bovine patch angioplasty concurrently with a polytetrafluoroethylene AV graft between common femoral artery and common femoral vein was performed to restore venous patency and allow rescue dialysis access. At 3-year follow-up, the fistula remains widely patent with 2 L/min flow rates and no recurrent stenosis to the treated iliac vein. She has not required any further surgical or interventional radiological procedures to maintain fistula or central venous patency. Central venous stenosis or occlusion is common for patients requiring dialysis, especially those with multiple previous long-term central venous cannulations. If restriction of outflow is present, AVF may fail. Venous patch angioplasty in these cases is a successful technique, allowing AVF formation and long-term patency. Central venous stenosis can be treated successfully with patch venoplasty to accommodate AVF/AVG formation for rescue vascular access; this is a potentially lifesaving intervention for patients requiring dialysis. Copyright © 2016 Elsevier Inc. All rights reserved.

Practical aspects of treatment with target specific anticoagulants: initiation, payment and current market, transitions, and venous thromboembolism treatment.

PubMed

Mahan, Charles E

2015-04-01

Target specific anticoagulants (TSOACs) have recently been introduced to the US market for multiple indications including venous thromboembolism (VTE) prevention in total hip and knee replacement surgeries, VTE treatment and reduction in the risk of stroke in patients with non-valvular atrial fibrillation (NVAF). Currently, three TSOACs are available including rivaroxaban, apixaban, and dabigatran with edoxaban currently under Food and Drug Administration review for VTE treatment and stroke prevention in NVAF. The introduction of these agents has created a paradigm shift in anticoagulation by considerably simplifying treatment and anticoagulant initiation for patients by giving clinicians the opportunity to use a rapid onset, rapid offset, oral agent. The availability of these rapid onset TSOACs is allowing for outpatient treatment of low risk pulmonary embolism and deep vein thrombosis which can greatly reduce healthcare costs by avoiding inpatient hospitalizations and treatment for the disease. Additionally with this practice, the complications of an inpatient hospitalization may also be avoided such as nosocomial infections. Single-agent approaches with TSOACs represent a paradigm shift in the treatment of VTE versus the complicated overlap of a parenteral agent with warfarin. Transitions between anticoagulants, including TSOACs, are a high-risk period for the patient, and clinicians must carefully consider patient characteristics such as renal function as well as the agents that are being transitioned. TSOAC use appears to be growing slowly with improved payment coverage throughout the US.

Tapping but not massage enhances vasodilation and improves venous palpation of cutaneous veins.

PubMed

Ichimura, Mika; Sasaki, Shinsuke; Mori, Masaharu; Ogino, Tetsuya

2015-01-01

This paper investigated whether tapping on the median cubital vein or massaging the forearm was more effective in obtaining better venous palpation for venipuncture. Forty healthy volunteers in their twenties were subjected to tapping (10 times in 5 sec) or massage (10 strokes in 20 sec from the wrist to the cubital fossa) under tourniquet inflation on the upper arm. Venous palpation was assessed using the venous palpation score (0-6, with 0 being impalpable). Three venous factors-venous depth, cross-sectional area, and elevation-were also measured using ultrasonography. The venous palpation score increased significantly by tapping but not by massage. Moreover, all 3 venous measurements changed significantly by tapping, while only the depth decreased significantly by massage. The three venous measurements correlated significantly with the venous palpation score, indicating that they are useful objective indicators for evaluating vasodilation. We suggest that tapping is an effective vasodilation technique.

Hepatic venous connection to a persistent inferior caval vein in left isomerism.

PubMed

Guenthard, J; Carvalho, J S; Anderson, R H; Rigby, M L

1990-09-01

In 22 cases of left atrial isomerism studied at the Brompton Hospital, four cases were found to have an unusual arrangement of the abdominal vessels. There was persistence of an inferior caval vein, partially anomalous hepatic venous connection and additional continuation of part of the venous return from the lower body through the azygos venous system. This venous pattern had surgical implications in our index case, since redirection of the inferior caval venous return was necessary.

Multidetector CT of blunt traumatic venous injuries in the chest, abdomen, and pelvis.

PubMed

Holly, Brian P; Steenburg, Scott D

2011-01-01

Venous injuries as a result of blunt trauma are rare. Even though current protocols for multidetector computed tomography (CT) of patients with trauma are designed to evaluate primarily the solid organs and arteries, blunt venous injuries may nevertheless be identified, or at least suspected, on the basis of the multidetector CT findings. Venous injuries are associated with high morbidity and mortality rates. Diagnosis of a possible venous injury is crucial because the physical findings of a venous injury are nonspecific and may be absent. This article aims to make the radiologist aware of various venous injuries caused by blunt trauma and to provide helpful hints to aid in the identification of venous injuries. Multidetector CT technology, in combination with interactive manipulation of the raw dataset, can be useful in the creation of multiplanar reconstructed images and in the identification of a venous injury caused by blunt trauma. Familiarity with direct and indirect signs of venous injuries, as well as with examples of blunt traumatic venous injuries in the chest, abdomen, and pelvis, will help in the diagnosis of these injuries.

21 CFR 884.5380 - Contraceptive tubal occlusion device (TOD) and introducer.

Code of Federal Regulations, 2012 CFR

2012-04-01

... 21 Food and Drugs 8 2012-04-01 2012-04-01 false Contraceptive tubal occlusion device (TOD) and... Gynecological Therapeutic Devices § 884.5380 Contraceptive tubal occlusion device (TOD) and introducer. (a) Identification. A contraceptive tubal occlusion device (TOD) and introducer is a device designed to close a...

21 CFR 884.5380 - Contraceptive tubal occlusion device (TOD) and introducer.

Code of Federal Regulations, 2010 CFR

2010-04-01

... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Contraceptive tubal occlusion device (TOD) and... Gynecological Therapeutic Devices § 884.5380 Contraceptive tubal occlusion device (TOD) and introducer. (a) Identification. A contraceptive tubal occlusion device (TOD) and introducer is a device designed to close a...

21 CFR 884.5380 - Contraceptive tubal occlusion device (TOD) and introducer.

Code of Federal Regulations, 2014 CFR

2014-04-01

... 21 Food and Drugs 8 2014-04-01 2014-04-01 false Contraceptive tubal occlusion device (TOD) and... Gynecological Therapeutic Devices § 884.5380 Contraceptive tubal occlusion device (TOD) and introducer. (a) Identification. A contraceptive tubal occlusion device (TOD) and introducer is a device designed to close a...

21 CFR 884.5380 - Contraceptive tubal occlusion device (TOD) and introducer.

Code of Federal Regulations, 2011 CFR

2011-04-01

... 21 Food and Drugs 8 2011-04-01 2011-04-01 false Contraceptive tubal occlusion device (TOD) and... Gynecological Therapeutic Devices § 884.5380 Contraceptive tubal occlusion device (TOD) and introducer. (a) Identification. A contraceptive tubal occlusion device (TOD) and introducer is a device designed to close a...

21 CFR 884.5380 - Contraceptive tubal occlusion device (TOD) and introducer.

Code of Federal Regulations, 2013 CFR

2013-04-01

... 21 Food and Drugs 8 2013-04-01 2013-04-01 false Contraceptive tubal occlusion device (TOD) and... Gynecological Therapeutic Devices § 884.5380 Contraceptive tubal occlusion device (TOD) and introducer. (a) Identification. A contraceptive tubal occlusion device (TOD) and introducer is a device designed to close a...

Venous and Arterial Thromboses: Two Sides of the Same Coin?

PubMed

Lippi, Giuseppe; Favaloro, Emmanuel J

2018-04-01

Arterial and venous thromboses are sustained by development of intraluminal thrombi, respectively, within the venous and arterial systems. The composition and structure of arterial and venous thrombi have been historically considered as being very different. Arterial thrombi (conventionally defined as "white") have been traditionally proposed to be composed mainly of fibrin and platelet aggregates, whilst venous thrombi (conventionally defined as "red") have been proposed as mostly being enriched in fibrin and erythrocytes. This archaic dichotomy seems ever more questionable, since it barely reflects the pathophysiology of thrombus formation in vivo. Both types of thrombi are actually composed of a complex fibrin network but, importantly, also contain essentially the same blood-borne cells (i.e., red blood cells, leukocytes, and platelets), and it is only the relative content of these individual elements that differ between venous and arterial clots or, otherwise, between thrombi generated under different conditions of blood flow and shear stress. Convincing evidence now suggests that either white or red intracoronary thrombi may be present in patients with myocardial infarction and, even more importantly, red thrombi may be more prone to distal embolization during percutaneous coronary intervention than those with lower content of erythrocytes. Conversely, it is now accepted that components traditionally considered to be involved "only" in arterial thrombosis are also represented in venous thrombosis. Thus, platelets comprise important components of venous clots, although they may be present in lower amounts here than in arterial thrombi, and von Willebrand factor is also represented in both arterial and venous thrombi. Of importance, such evidence thus supports the concept that adjunctive treatment normally associated to prevention of arterial thrombosis (e.g., aspirin) may have a role also in prevention and treatment of venous thrombosis. Thieme Medical

Deep venous thrombosis and postthrombotic syndrome: invasive management.

PubMed

Comerota, A J

2015-03-01

Invasive management of postthrombotic syndrome encompasses the two ends of the deep vein thrombosis spectrum, patients with acute iliofemoral deep vein thrombosis and those with chronic postthrombotic iliofemoral venous obstruction. Of all patients with acute deep vein thrombosis, those with involvement of the iliofemoral segments have the most severe chronic postthrombotic morbidity. Catheter-based techniques now permit percutaneous treatment to eliminate thrombus, restore patency, potentially maintain valvular function, and improve quality of life. Randomized trial data support an initial treatment strategy of thrombus removal. Failure to eliminate acute thrombus from the iliofemoral system leads to chronic postthrombotic obstruction of venous outflow. Debilitating chronic postthrombotic symptoms of the long-standing obstruction of venous outflow can be reduced by restoring unobstructed venous drainage from the profunda femoris vein to the vena cava. © The Author(s) 2015 Reprints and permissions: sagepub.co.uk/journalsPermissions.nav.

Levodopa-carbidopa with occlusion in older children with amblyopia.

PubMed

Bhartiya, Prashant; Sharma, Pradeep; Biswas, Nihar R; Tandon, Radhika; Khokhar, Sudarshan K

2002-12-01

To study the role of levodopa-carbidopa in supplementing occlusion therapy in older children with strabismic or anisometropic amblyopia. A clinical study was performed on 40 amblyopic children (19 strabismic and 21 anisometropic), 6 to 18 years old (mean age, 10.9 years). They received an average dose of 1.86 mg/kg/day (1.33-2.36 mg/kg/day) of levodopa and carbidopa (4:1 ratio) or a placebo in 3 divided doses over a 4-week period, combined with full-time occlusion. The occlusion was continued for the study duration of 3 months. Early Treatment Diabetic Retinopathy Study visual acuity charts and Cambridge low-contrast gratings for contrast sensitivity (CS) were used to assess visual functions. Tolerance and compliance with occlusion and capsule consumption were assessed. Visual acuity of the nonamblyopic eye did not deteriorate during the study in either group. CS decreased by 22 units in the levodopa group and increased in the placebo group by 53 units at the first month. The CS in the levodopa group recovered later by the third month of follow-up. Both the levodopa and the placebo groups showed significant improvement in visual function in the amblyopic eye (P <.001). Overall changes in logarithm of minimum angle of resolution values and CS in the amblyopic eyes were similar in both groups (P >.05). Strabismic and anisometropic amblyopes did not behave differently. Drug tolerance, occlusion compliance, and capsule ingestion compliance were similar between the groups, with no significant side effects. Clinically, levodopa supplementation does not offer any advantage over occlusion alone. Moreover, the risk of occlusion amblyopia could increase with the use of drugs like levodopa that might affect the plasticity of the visual cortex.

[Venous tone of the limbs. Methods and comparison of 2 areas].

PubMed

Journo, H; London, G; Pannier, B; Safar, M

1989-07-01

The limb venous tone, index of local venous compliance, was studied with mercury strain gauge plethysmography on 28 male normal subjects (40 +/- 17 years, +/- SD) simultaneously on upper and lower limbs. Measurements were done after 20 mn rest in supine position. Venous tone (VT) equals the slope of the pressure-volume curve established by simultaneous recording of the forearm and calf relative volumes for successive steps of pressure lower than or equal to 30 mmHg. Limb venous capacitance was expressed by means of the maximal limb relative volume (V30) reached for a pressure of 30 mmHg applied through cuffs in standardized conditions. The upper limb venous tone was greater than the lower limb venous tone: 24.3 +/- 8.2 mmHg/ml/100 vs 17.5 +/- 7.9 mmHg/ml/100, p = 0.001. V30 was greater in lower limb than in upper limb: 1.5 +/- 0.5 ml/100 vs 1.1 +/- 0.4 ml/100, p = 0.001. In conclusion, it appears that upper and lower limbs venous distensibility and capacitance are different. They are greater in the lower limb in baseline conditions. Thus simultaneous studies of both these limb venous systems seems important for physiological experiments because of their baseline differences.

Hypothalamic digoxin, hemispheric chemical dominance, and mesenteric artery occlusion.

PubMed

Kurup, Ravi Kumar; Kurup, Paramesware Achutha

2003-12-01

The role of the isoprenoid pathway in vascular thrombosis, especially mesenteric artery occlusion and its relation to hemispheric dominance, was assessed in this study. The following parameters were measured in patients with mesenteric artery occlusion and individuals with right hemispheric, left hemispheric, and bihemispheric dominance: (1) plasma HMG CoA reductase, digoxin, dolichol, ubiquinone, and magnesium levels; (2) tryptophan/tyrosine catabolic patterns; (3) free radical metabolism; (4) glycoconjugate metabolism; and (5) membrane composition. In patients with mesenteric artery occlusion there was elevated digoxin synthesis, increased dolichol and glycoconjugate levels, low ubiquinone, and elevated free radical levels. The RBC membrane Na(+)-K+ ATPase activity and serum magnesium were decreased. There was also an increase in tryptophan catabolites and reduction in tyrosine catabolites in the serum. There was an increase in cholesterol:phospholipid ratio and a reduction in glycoconjugate level of RBC membrane in these patients. The biochemical patterns obtained in mesenteric artery occlusion is similar to those obtained in left-handed/right hemispheric dominant individuals by the dichotic listening test. But all the patients with mesenteric artery occlusion were right-handed/left hemispheric dominant by the dichotic listening test. Hemispheric chemical dominance has no correlation with handedness or the dichotic listening test. Mesenteric artery occlusion occurs in right hemispheric chemically dominant individuals and is a reflection of altered brain function. Hemispheric chemical dominance may thus control the risk for developing vascular thrombosis in individuals.

Increased carboxyhemoglobin level during liver resection with inflow occlusion.

PubMed

Godai, Kohei; Hasegawa-Moriyama, Maiko; Kuniyoshi, Tamotsu; Matsunaga, Akira; Kanmura, Yuichi

2013-04-01

Controlling stress responses associated with ischemic changes due to bleeding and ischemia/reperfusion injury is essential for anesthetic management. Endogenous carboxyhemoglobin (COHb) is produced in the oxidative degradation of heme proteins by the stress-response enzyme heme oxygenase. Although the COHb level is elevated in critically ill patients, changes in endogenous COHb during anesthesia have not been well investigated. Therefore, we evaluated changes in endogenous COHb levels in patients undergoing liver resections with inflow occlusion. Levels of COHb were significantly increased after the Pringle maneuver. The inflow occlusion time in patients with increased COHb after the Pringle maneuver (∆COHb > 0.3 %) was significantly longer than in patients without increased COHb (∆COHb < 0.3 %) (P = 0.01). In addition, COHb changes were correlated with inflow occlusion time (P = 0.005, R(2) = 0.21). Neither total blood loss, transfusion volume of packed red blood cells, operation time, nor anesthetic time differed between patients with and without increased COHb. The results indicated that endogenous COHb levels were increased by inflow occlusion in patients undergoing liver resections, which suggests that changes in COHb may correlate with hepatic ischemia/reperfusion injury induced by inflow occlusion.

Combined Recirculatory-compartmental Population Pharmacokinetic Modeling of Arterial and Venous Plasma S(+) and R(-) Ketamine Concentrations.

PubMed

Henthorn, Thomas K; Avram, Michael J; Dahan, Albert; Gustafsson, Lars L; Persson, Jan; Krejcie, Tom C; Olofsen, Erik

2018-05-16

The pharmacokinetics of infused drugs have been modeled without regard for recirculatory or mixing kinetics. We used a unique ketamine dataset with simultaneous arterial and venous blood sampling, during and after separate S(+) and R(-) ketamine infusions, to develop a simplified recirculatory model of arterial and venous plasma drug concentrations. S(+) or R(-) ketamine was infused over 30 min on two occasions to 10 healthy male volunteers. Frequent, simultaneous arterial and forearm venous blood samples were obtained for up to 11 h. A multicompartmental pharmacokinetic model with front-end arterial mixing and venous blood components was developed using nonlinear mixed effects analyses. A three-compartment base pharmacokinetic model with additional arterial mixing and arm venous compartments and with shared S(+)/R(-) distribution kinetics proved superior to standard compartmental modeling approaches. Total pharmacokinetic flow was estimated to be 7.59 ± 0.36 l/min (mean ± standard error of the estimate), and S(+) and R(-) elimination clearances were 1.23 ± 0.04 and 1.06 ± 0.03 l/min, respectively. The arm-tissue link rate constant was 0.18 ± 0.01 min and the fraction of arm blood flow estimated to exchange with arm tissue was 0.04 ± 0.01. Arterial drug concentrations measured during drug infusion have two kinetically distinct components: partially or lung-mixed drug and fully mixed-recirculated drug. Front-end kinetics suggest the partially mixed concentration is proportional to the ratio of infusion rate and total pharmacokinetic flow. This simplified modeling approach could lead to more generalizable models for target-controlled infusions and improved methods for analyzing pharmacokinetic-pharmacodynamic data.

Risk factors associated with PICC-related upper extremity venous thrombosis in cancer patients.

PubMed

Yi, Xiao-lei; Chen, Jie; Li, Jia; Feng, Liang; Wang, Yan; Zhu, Jia-An; Shen, E; Hu, Bing

2014-03-01

To investigate the incidence and risk factors for peripherally inserted central venous catheters-related upper extremity venous thrombosis in patients with cancer. With the widespread use of peripherally inserted central venous catheters, peripherally inserted central venous catheters-related upper extremity venous thrombosis in patients with cancer leads to increasing morbidity and mortality. It is very important to further explore the incidence and risk factors for peripherally inserted central venous catheters-related venous thrombosis. Consecutive patients with cancer who were scheduled to receive peripherally inserted central venous catheters, between September 2009 and May 2012, were prospectively studied in our centre. They were investigated for venous thrombosis by Doppler sonography three times a day within 30 days after catheter insertion. Univariable and multivariable logistic regressions' analyses were performed to identify the risk factors for peripherally inserted central venous catheters-related thrombosis. A total of 89 patients with cancer were studied in our research. Of these, 81 patients were followed up within one month. The mean interval between catheter insertion and the onset of thrombosis was 12.45 ± 6.17 days. The multivariable analyses showed that chemotherapy history, less activities and diabetes were the key risk factors for thrombosis. Peripherally inserted central venous catheters-related upper extremity venous thrombosis had high incidence rate, and most cases had no significant symptoms. The history of chemotherapy, less activities and diabetes were found to be the key risk factors. It should be routinely scanned in high-risk patients every 3-5 days after catheter insertion, which would then find blood clots in time and reduce the incidence of pulmonary embolism. Risk factors associated with peripherally inserted central venous catheters-related upper extremity venous thrombosis are of critical importance in improving the quality

Focal retinal phlebitis.

PubMed

Hoang, Quan V; Freund, K Bailey; Klancnik, James M; Sorenson, John A; Cunningham, Emmett T; Yannuzzi, Lawrence A

2012-01-01

To report three cases of solitary, focal retinal phlebitis. An observational case series. Three eyes in three patients were noted to have unilateral decreased vision, macular edema, and a focal retinal phlebitis, which was not at an arteriovenous crossing. All three patients developed a branch retinal vein occlusion at the site of inflammation. These patients had no other evidence of intraocular inflammation, including vitritis, retinitis, retinal vasculitis, or choroiditis, nor was there any systemic disorder associated with inflammation, infection, or coagulation identified. Focal retinal phlebitis appears to be an uncommon and unique entity that produces macular edema and ultimately branch retinal vein occlusion. In our patients, the focal phlebitis and venous occlusion did not occur at an arteriovenous crossing, which is the typical site for branch retinal venous occlusive disease. This suggests that our cases represent a distinct clinical entity, which starts with a focal abnormality in the wall of a retinal venule, resulting in surrounding exudation and, ultimately, ends with branch retinal vein occlusion.

Complete occlusion after blunt injury to the abdominal aorta.

PubMed

Meghoo, Colin A L; Gonzalez, Ernest A; Tyroch, Alan H; Wohltmann, Christopher D

2003-10-01

Injury to the abdominal aorta after blunt trauma is uncommon. When this injury results in complete vessel occlusion, the presentation is dramatic. Timely intervention is essential. After a case report, we examined all reported cases of complete occlusion after blunt injury to the abdominal aorta and reviewed the cause, presentation, and management of this injury. Complete vessel occlusion arises from intimal injury. The most frequent mechanism is compression from a seat belt or steering wheel during a motor vehicle crash. Patients present with absent femoral and distal pulses in association with lower extremity neuropathy. Intervention commonly involves bypass grafting of the abdominal aorta. Complete occlusion after blunt trauma to the abdominal aorta is rare. Neurologic deficits most commonly arise from peripheral nerve ischemia. Reperfusion within 6 hours confers a greater chance of limb salvage and neurologic recovery.

Aphid watery saliva counteracts sieve-tube occlusion: a universal phenomenon?

PubMed

Will, Torsten; Kornemann, Sarah R; Furch, Alexandra C U; Tjallingii, W Fred; van Bel, Aart J E

2009-10-01

Ca2+-binding proteins in the watery saliva of Megoura viciae counteract Ca2+-dependent occlusion of sieve plates in Vicia faba and so prevent the shut-down of food supply in response to stylet penetration. The question arises whether this interaction between aphid saliva and sieve-element proteins is a universal phenomenon as inferred by the coincidence between sieve-tube occlusion and salivation. For this purpose, leaf tips were burnt in a number of plant species from four different families to induce remote sieve-plate occlusion. Resultant sieve-plate occlusion in these plant species was counteracted by an abrupt switch of aphid behaviour. Each of the seven aphid species tested interrupted its feeding behaviour and started secreting watery saliva. The protein composition of watery saliva appeared strikingly different between aphid species with less than 50% overlap. Secretion of watery saliva seems to be a universal means to suppress sieve-plate occlusion, although the protein composition of watery saliva seems to diverge between species.

Computational modeling of venous sinus stenosis in idiopathic intracranial hypertension

PubMed Central

Levitt, Michael R; McGah, Patrick M; Moon, Karam; Albuquerque, Felipe C; McDougall, Cameron G; Kalani, M Yashar S; Kim, Louis J; Aliseda, Alberto

2016-01-01

Background and Purpose Idiopathic intracranial hypertension has been associated with dural venous sinus stenosis in some patients, but the hemodynamic environment of the dural venous sinuses has not been quantitatively described. Here, we present the first such computational fluid dynamics model using patient-specific blood pressure measurements. Materials and Methods Six patients with idiopathic intracranial hypertension and at least one stenosis or atresia at the transverse-sigmoid sinus junction underwent MRV followed by cerebral venography and manometry throughout the dural venous sinuses. Patient-specific computational fluid dynamics models were created using MRV anatomy, with venous pressure measurements as boundary conditions. Blood flow and wall shear stress were calculated for each patient. Results Computational models of dural venous sinuses were successfully reconstructed in all six patients with patient-specific boundary conditions. Three patients demonstrated a pathologic pressure gradient (≥ 8 mm Hg) across four dural venous sinus stenoses. Small sample size precludes statistical comparisons, but average overall flow throughout the dural venous sinuses of patients with pathologic pressure gradients was higher than in those without (1041.00 ± 506.52 vs. 358.00 ± 190.95 mL/min). Wall shear stress was also higher across stenoses in patients with pathologic pressure gradients (37.66 ± 48.39 vs 7.02 ± 13.60 Pa). Conclusion The hemodynamic environment of the dural venous sinuses can be computationally modeled using patient-specific anatomy and physiological measurements in patients with idiopathic intracranial hypertension. There was substantially higher blood flow and wall shear stress in patients with pathological pressure gradients. PMID:27197986