21 CFR 870.3375 - Cardiovascular intravascular filter.

Code of Federal Regulations, 2013 CFR

2013-04-01

... 21 Food and Drugs 8 2013-04-01 2013-04-01 false Cardiovascular intravascular filter. 870.3375... Cardiovascular intravascular filter. (a) Identification. A cardiovascular intravascular filter is an implant that... and Revision of 2/12/90 (K90-1)” and (ii) “Guidance for Cardiovascular Intravascular Filter 510(k...

Effect of intravascular irradiation of He-Ne laser on cerebral infarction: Hemorrheology and apoptosis

NASA Astrophysics Data System (ADS)

Zhu, Jian; Liang, Min-yi; Cao, Hao-cai; Li, Xiao-Yuan; Li, Shao-ming; Li, Shun-hao; Li, Wen-qi; Zhang, Jin-hong; Liu, Lei; Lai, Jian-hong

2005-07-01

Objective: To explore the efficacy of He-Ne laser intravascular irradiation on infarction and hemorrheology. To observe the effects of intravascular low level He-Ne laser irradiation (ILLLI) of blood on cell proliferation, apoptosis and chromosome in lymphocyte from cerebral infarction Methods: Seventy cases with cerebral infarction were randomly divided into groups control group (35 cases) treated only with common drugs and therapeutic group (35 cases) treated besides common drugs also by He-Ne laser intravascular irradiation. Their hemorrheology index and treatment results were observed and compared. The blood lymphocytes of cerebral infarction were cultured before and after treatment. After that, the mitosis index (MI), cell kinetics index (CKI), sister-chromatid exchanges (SCE) frequencies and apoptosis were determined. Results The therapeutic group was better than the control one. The effective rate in the therapeutic group was 88.6%, in the control one was 65.7%. The viscosity and fibrinogen, etc were better than that in the control group with significant difference (P<0.01). The lymphocyte proliferation index was significantly two increased than the control one (P>0.05) in cerebral infarction patients after treatment; The CKI of lymphocytes had no obvious difference among groups (P>0.05) SCE frequencies of lymphocytes had no statistic significance between control group and ILLLI on (P>0.05). It showed the apoptosis rate of lymphocytes in cerebral infarction patients after ILLLI treatment increased significantly compared with the control group, (P<0.001). There was a significant difference of apoptosis rate of lymphocytes in cerebral infarction patients than the control (P<0.001). Conclusions: During the He-Ne laser intravascular irradiation of the cerebral infarction, the low level He-Ne by ILLLI can increase the proliferation of lymphocytes, and can induce lymphocytes to apoptosis, but has no mutagenicity of cells.

Mechanical behavior of deformed intravascular NiTi stents differing in design. Numerical simulation

NASA Astrophysics Data System (ADS)

Eremina, Galina M.; Smolin, Alexey Yu.; Krukovskii, Konstantin V.; Lotkov, Aleksandr I.; Kashin, Oleg A.; Kudryashov, Andrey N.

2017-12-01

Self-expanding intravascular NiTi stents serve to recover the lumen of vessels suffered from atherosclerotic stenosis. During their manufacturing or functioning in blood vessels, the stents experience different strains and local stresses that may result in dangerous defects or fracture. Here, using the method of movable cellular automata, we analyze how the design of a stent influences its stress state during shaping to a desired diameter on a mandrel. We consider repeated segments of different stents under two loads: uniform diametric expansion of their crown and expansion with relative displacements. The simulation data agree well with experiments, revealing critical strain, stress, and their localization sites at the shaping stage, and provide the way toward optimum stent designs to minimize the critical stress during shaping.

The intravascular low level laser irradiation (ILLLI) in treatment of psoriasis clinically

NASA Astrophysics Data System (ADS)

Zhu, Jing; Nie, Fan; Shi, Hong-Min

2005-07-01

Objective: The title is research curative effect of intravascular low level laser irradiation (ILLLI) in treatment of psoriasis. Method: 478 patients with psoriasis from five groups to observe their efficacy. Group1 were treated by He-Ne laser combined with drug. Group 2 were treated by semi-conductor laser combined with drug. Group 3 were treated only by He-He laser. Group 4 were treated by semi-conductor laser. Group 5 were treated only by drug. The Ridit statistical analysis was applied to all of these data. The treatment of intravascular low level laser irradiation is as follow: laser power:4-5mw, 1 hour per day and 10 days as a period combined with vit C 2.0 g iv and inhalation of O2. Results: The clinical results: the near efficient rate was 100%, in group1-4, if combined with drugs it would be better. Ridit statistical analysis showed no significant difference between group1-4, p>0.05. The efficient rate 72.97% in group5.There were showed very significant difference with group1-4, p<0.01. 2.There were no significant differences between He-Ne laser (632.8nm) and semiconductor laser(650nm); 3.The efficacy of ILLLI in psoriasis was positive correlation to the ILLLI times. Conclusions: It can improve curative effect of intravascular low levellaser irradiation (ILLLI) in treatment of psoriasis.

Bacillus cereus causing fulminant sepsis and hemolysis in two patients with acute leukemia.

PubMed

Arnaout, M K; Tamburro, R F; Bodner, S M; Sandlund, J T; Rivera, G K; Pui, C H; Ribeiro, R C

1999-01-01

Hemolysis is so rarely associated with Bacillus cereus sepsis that only two very well documented cases have been reported. This article reports two unusual cases of Bacillus cereus sepsis with massive intravascular hemolysis in patients who had acute lymphoblastic leukemia (ALL). A 20-year-old woman who was 9 weeks pregnant experienced a relapse of ALL. A therapeutic abortion was performed. During week 4 of reinduction the patient had abdominal pain, nausea, and vomiting, with severe neutropenia but no fever. Her condition deteriorated rapidly with cardiovascular collapse, acute massive intravascular hemolysis, and death within hours of the onset of symptoms. Blood cultures were positive for Bacillus cereus. Postmortem histologic examination and cultures revealed Bacillus cereus and Candida albicans in multiple organs. The second patient, a 10-year-old girl, presented with relapsed T-cell ALL. In the second week of reinduction, she had abdominal pain followed by hypotension. Again, no fever was noted. Laboratory studies showed intravascular hemolysis 12 hours after admission. Aggressive support was promptly initiated. Despite disseminated intravascular coagulation; cardiovascular, hepatic, and renal failure; and multiple intracerebral hypodense lesions believed to be infarcts, the patient recovered fully and resumed reinduction therapy. Bacillus cereus infection can have a fulminant clinical course that may be complicated by massive intravascular hemolysis. This pathogen should be suspected in immunosuppressed patients who experience gastrointestinal symptoms and should not be precluded by the absence of fever, especially if steroids such as dexamethasone are being given. Exchange transfusion may be lifesaving in Bacillus cereus septicemia associated with massive hemolysis.

Effect of hydration on some orthostatic and haematological responses to head-up tilt

NASA Technical Reports Server (NTRS)

Harrison, M. H.; Hill, L. C.; Spaul, W. A.; Greenleaf, J. E.

1986-01-01

Experiments were undertaken to determine the effects of hydration status on: (1) orthostatic responses, and on (2) relative changes in intravascular volume and protein content, during 70 deg head-up tilt (HUT). Six men underwent 45 min of HUT, preceded by 45 min supine, first dehydrated, and again 105 min later after rehydration with water. Heart rate was consistently lower following rehydration (p less than 0.01), while supine diastolic pressure was higher (p less than 0.02). Systolic pressure fell during dehydrated HUT (p less than 0.01), but not during rehydrated HUT. Postural haemoconcentration, which was reduced after rehydration (p less than 0.001), was accompanied by a decrease in intravascular albumin content (p less than 0.05). Two subjects experienced severe presyncopal symptoms during dehydrated HUT, but not during rehydrated HUT. Thus, it appears that rehydration after fluid restriction improves orthostatic tolerance. Furthermore, extravascular hydration status may be more important than intravascular hydration status in determining orthostatic tolerance.

Positron autoradiography for intravascular imaging: feasibility evaluation

NASA Astrophysics Data System (ADS)

Shikhaliev, Polad M.; Xu, Tong; Ducote, Justin L.; Easwaramoorthy, Balasubramaniam; Mukherjee, Jogeshwar; Molloi, Sabee

2006-02-01

Approximately 70% of acute coronary artery disease is caused by unstable (vulnerable) plaques with an inflammation of the overlying cap and high lipid content. A rupturing of the inflamed cap of the plaque results in propagation of the thrombus into the lumen, blockage of the artery and acute ischaemic syndrome or sudden death. Morphological imaging such as angiography or intravascular ultrasound cannot determine inflammation status of the plaque. A radiotracer such as 18F-FDG is accumulated in vulnerable plaques due to higher metabolic activity of the inflamed cap and could be used to detect a vulnerable plaque. However, positron emission tomography (PET) cannot detect the FDG-labelled plaques because of respiratory and heart motions, small size and low activity of the plaques. Plaques can be detected using a miniature particle (positron) detector inserted into the artery. In this work, a new detector concept is investigated for intravascular imaging of the plaques. The detector consists of a storage phosphor tip bound to the end of an intravascular catheter. It can be inserted into an artery, absorb the 18F-FDG positrons from the plaques, withdrawn from the artery and read out. Length and diameter of the storage phosphor tip can be matched to the length and the diameter of the artery. Monte Carlo simulations and experimental evaluations of coronary plaque imaging with the proposed detector were performed. It was shown that the sensitivity of the storage phosphor detector to the positrons of 18F-FDG is sufficient to detect coronary plaques with 1 mm and 2 mm sizes and 590 Bq and 1180 Bq activities in the arteries with 2 mm and 3 mm diameters, respectively. An experimental study was performed using plastic tubes with 2 mm diameter filled with an FDG solution, which simulates blood. FDG spots simulating plaques were placed over the surface of the tube. A phosphor tip was inserted into the tube and imaged the plaques. Exposure time was 1 min in all simulations and experiments. Experiments showed that detecting the coronary plaques using the proposed technique is possible. The proposed technique has the potential for fast and accurate detection of vulnerable coronary and other intravascular plaques.

Intrauterine intravascular transfusion for fetal haemolytic anaemia: the Western Australian experience.

PubMed

Newnham, J P; Phillips, J M; Stock, R

1992-11-16

To report the first four years' clinical experience with fetal intravascular blood transfusion for the treatment of fetal haemolytic anaemia in Western Australia. King Edward Memorial Hospital, Perth, which is the sole tertiary level perinatal centre in Western Australia with a referral base of approximately 25,000 pregnancies each year. Transfusion was by injection of packed cells from Rh-negative donors into the fetal umbilical vein near the site of insertion into the placenta. Fetal haemoglobin levels were measured before and after each transfusion. In most cases, the fetus was paralysed by intramuscular tubocurarine. Sixty intravenous transfusions were performed in 20 pregnancies. At the time of the initial transfusion, the mean haemoglobin level was 5.8 g/dL (range, 2.5-8.5 g/dL) and six fetuses had signs of hydrops. The case survival rate was 80% and the procedure survival rate was 93%. Three of the deaths occurred in the first five cases. Caesarean section was performed during two of the procedures, one because of bleeding from the cord puncture site and one because of tamponade of the umbilical vessels. Fetal intravascular transfusion is a highly effective treatment for fetal alloimmunisation and allows pregnancies to continue to term and to be delivered vaginally. However, the procedure may be difficult and requires a team approach with ready access to fetal monitoring and emergency caesarean section. Our results suggest that increasing experience of the team is a major factor in improved outcome.

Extraforaminal needle tip position reduces risk of intravascular injection in CT-fluoroscopic lumbar transforaminal epidural steroid injections

PubMed Central

Yu, Robinson K.; Ghodadra, Anish; Agarwal, Vikas

2016-01-01

Background Lumbar transforaminal epidural steroid injection is a common and effective tool for managing lumbar radicular pain, although accidental intravascular injection can rarely result in paralysis. The purpose of this study is to determine the safest needle tip position for computed tomography (CT)-guided lumbar transforaminal epidural steroid injections as determined by incidence of intravascular injection. Methods Three radiologists, in consensus, reviewed procedural imaging for consecutive CT-fluoroscopic lumbar transforaminal epidural steroid injections performed during a 16-month period. Intravascular injections were identified and categorized by needle tip position, vessel type injected, intravascular injection volume and procedural phase containing the intravascular injection. Pearson chi-square and logistic regression testing were used to assess differences between groups, as appropriate. Results Intravascular injections occurred in 9% (52/606) of injections. The intravascular injection rate was significantly lower (P<0.001) for extraforaminal needle position (0%, 0/109) compared to junctional (8%, 27/319) and foraminal (14%, 25/178) needle tip positions. Of the intravascular injections, 4% (2/52) were likely arterial, 35% (18/52) were likely venous, and 62% (32/52) were indeterminate for vessel type injected. 46% (24/52) of intravascular injections were large volume, 33% (17/52) were small volume, and 21% (11/52) were trace volume. 56% (29/52) of intravascular injections occurred with the contrast trial dose, 29% (15/52) with the steroid/analgesic cocktail, and 15% (8/52) with both. Conclusions An extraforaminal needle position for CT-fluoroscopic lumbar transforaminal epidural steroid injections decreases the risk of intravascular injection and therefore may be safer than other needle tip positions. PMID:28097241

21 CFR 880.5965 - Subcutaneous, implanted, intravascular infusion port and catheter.

Code of Federal Regulations, 2010 CFR

2010-04-01

... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Subcutaneous, implanted, intravascular infusion... Hospital and Personal Use Therapeutic Devices § 880.5965 Subcutaneous, implanted, intravascular infusion port and catheter. (a) Identification. A subcutaneous, implanted, intravascular infusion port and...

21 CFR 880.5965 - Subcutaneous, implanted, intravascular infusion port and catheter.

Code of Federal Regulations, 2011 CFR

2011-04-01

... 21 Food and Drugs 8 2011-04-01 2011-04-01 false Subcutaneous, implanted, intravascular infusion... Hospital and Personal Use Therapeutic Devices § 880.5965 Subcutaneous, implanted, intravascular infusion port and catheter. (a) Identification. A subcutaneous, implanted, intravascular infusion port and...

Comparison of incidence of intravascular injections during transforaminal epidural steroid injection using different needle types

PubMed Central

Lee, Yong Ho

2014-01-01

Background Infrequent but serious complications of transforaminal epidural steroid injection (TFESI) occur due to inadvertent intravascular injections. A few studies reported that the different needle types can influence on the occurrences of intravascular incidence in TFESI. This study prospectively evaluated whether short-bevel needle can reduce the incidences of intravascular injection of TFESI compared to long-bevel needles. Methods From March 2013 to December 2013, 239 consecutive patients were enrolled and received 249 fluoroscopically guided TFESI using the classic technique. Confirmation of intravascular spread was done initially with real time fluoroscopy and then with digital subtraction angiography method in a same patient. Injection technique for TFESI was the same for both short-bevel and long-bevel needle types. Results The incidences of intravascular injections with the long-bevel and short-bevel needles were 15.0% (21/140) and 9.2% (4/140), respectively. More than half of intravascular injections occurred simultaneously with epidural injections (8.0%, 20/249). There were no statistically significant differences between the long-bevel and the short-bevel needles in the rates of intravascular injections (P = 0.17). Conclusions Short-bevel needles did not demonstrate any benefits in reducing the incidence of intravascular injection. PMID:25302096

Effector CD4+ T cells recognize intravascular antigen presented by patrolling monocytes.

PubMed

Westhorpe, Clare L V; Norman, M Ursula; Hall, Pam; Snelgrove, Sarah L; Finsterbusch, Michaela; Li, Anqi; Lo, Camden; Tan, Zhe Hao; Li, Songhui; Nilsson, Susan K; Kitching, A Richard; Hickey, Michael J

2018-02-21

Although effector CD4 + T cells readily respond to antigen outside the vasculature, how they respond to intravascular antigens is unknown. Here we show the process of intravascular antigen recognition using intravital multiphoton microscopy of glomeruli. CD4 + T cells undergo intravascular migration within uninflamed glomeruli. Similarly, while MHCII is not expressed by intrinsic glomerular cells, intravascular MHCII-expressing immune cells patrol glomerular capillaries, interacting with CD4 + T cells. Following intravascular deposition of antigen in glomeruli, effector CD4 + T-cell responses, including NFAT1 nuclear translocation and decreased migration, are consistent with antigen recognition. Of the MHCII + immune cells adherent in glomerular capillaries, only monocytes are retained for prolonged durations. These cells can also induce T-cell proliferation in vitro. Moreover, monocyte depletion reduces CD4 + T-cell-dependent glomerular inflammation. These findings indicate that MHCII + monocytes patrolling the glomerular microvasculature can present intravascular antigen to CD4 + T cells within glomerular capillaries, leading to antigen-dependent inflammation.

Experience With Intravascular Ultrasound Imaging Of Human Atherosclerotic Arteries

NASA Astrophysics Data System (ADS)

Mallery, John A.; Gessert, James M.; Maciel, Mario; Tobis, John M.; Griffith, James M.; Berns, Michael W.; Henry, Walter L.

1989-08-01

Normal human arteries have a well-defined structure on intravascular images. The intima appears very thin and is most likely represented by a bright reflection arising from the internal elastic lamina. The smooth muscle tunica media is echo-lucent on the ultrasound image and appears as a dark band separating the intima from the adventitia. The adventitia is a brightly reflective layer of variable thickness. The thickness of the intima, and therefore of the atherosclerotic plaque can be accurately measured from the ultrasound images and correlates well with histology. Calcification within the wall of arteries is seen as bright echo reflection with shadowing of the peripheral wall. Fibrotic regions are highly reflective but do not shadow. Necrotic liquid regions within advanced atherosclerotic plaques are seen on ultrasound images as large lucent zones surrounded by echogenic tissue. Imaging can be performed before and after interventional procedures, such as laser angioplasty, balloon angioplasty and atherectomy. Intravascular ultrasound appears to provide an imaging modality for identifying the histologic characteristics of diseased arteries and for quantifying plaque thickness. It might be possible to perform such quantification to evaluate the results of interventional procedures.

High-intensity focused ultrasound sonothrombolysis: the use of perfluorocarbon droplets to achieve clot lysis at reduced acoustic power.

PubMed

Pajek, Daniel; Burgess, Alison; Huang, Yuexi; Hynynen, Kullervo

2014-09-01

The purpose of this study was to evaluate use of intravascular perfluorocarbon droplets to reduce the sonication power required to achieve clot lysis with high-intensity focused ultrasound. High-intensity focused ultrasound with droplets was initially applied to blood clots in an in vitro flow apparatus, and inertial cavitation thresholds were determined. An embolic model for ischemic stroke was used to illustrate the feasibility of this technique in vivo. Recanalization with intravascular droplets was achieved in vivo at 24 ± 5% of the sonication power without droplets. Recanalization occurred in 71% of rabbits that received 1-ms pulsed sonications during continuous intravascular droplet infusion (p = 0.041 vs controls). Preliminary experiments indicated that damage was confined to the ultrasonic focus, suggesting that tolerable treatments would be possible with a more tightly focused hemispheric array that allows the whole focus to be placed inside of the main arteries in the human brain. Copyright © 2014 World Federation for Ultrasound in Medicine & Biology. Published by Elsevier Inc. All rights reserved.

Transjugular intrahepatic portosystemic shunt creation using intravascular ultrasound guidance.

PubMed

Farsad, Khashayar; Fuss, Cristina; Kolbeck, Kenneth J; Barton, Robert E; Lakin, Paul C; Keller, Frederick S; Kaufman, John A

2012-12-01

To describe the use of intravascular ultrasound (US) guidance for creation of transjugular intrahepatic portosystemic shunts (TIPSs) in humans. The initial 25 cases of intravascular US-guided TIPS were retrospectively compared versus the last 75 conventional TIPS cases during the same time period at the same institution in terms of the number of needle passes required to establish portal vein (PV) access, fluoroscopy time, and needle pass-related complications. Intravascular US-guided TIPS creation was successful in all cases, and there was no statistically significant difference in number of needle passes, fluoroscopy time, or needle pass-related complications between TIPS techniques. Intravascular US-guided TIPS creation was successful in cases in which conventional TIPS creation had failed as a result of PV thrombosis or distorted anatomy. Intravascular US guidance for TIPS creation was additionally useful in a patient with Budd-Chiari syndrome and in a patient with intrahepatic tumors. Intravascular US is a safe and reproducible means of real-time image guidance for TIPS creation, equivalent in efficacy to conventional fluoroscopic guidance. Real-time sonographic guidance with intravascular US may prove advantageous for cases in which there is PV thrombus, distorted anatomy, Budd-Chiari syndrome, or hepatic tumors. Copyright © 2012 SIR. Published by Elsevier Inc. All rights reserved.

A Review of Intravascular Ultrasound–Based Multimodal Intravascular Imaging: The Synergistic Approach to Characterizing Vulnerable Plaques

PubMed Central

Ma, Teng; Zhou, Bill; Hsiai, Tzung K.; Shung, K. Kirk

2015-01-01

Catheter-based intravascular imaging modalities are being developed to visualize pathologies in coronary arteries, such as high-risk vulnerable atherosclerotic plaques known as thin-cap fibroatheroma, to guide therapeutic strategy at preventing heart attacks. Mounting evidences have shown three distinctive histopathological features—the presence of a thin fibrous cap, a lipid-rich necrotic core, and numerous infiltrating macrophages—are key markers of increased vulnerability in atherosclerotic plaques. To visualize these changes, the majority of catheter-based imaging modalities used intravascular ultrasound (IVUS) as the technical foundation and integrated emerging intravascular imaging techniques to enhance the characterization of vulnerable plaques. However, no current imaging technology is the unequivocal “gold standard” for the diagnosis of vulnerable atherosclerotic plaques. Each intravascular imaging technology possesses its own unique features that yield valuable information although encumbered by inherent limitations not seen in other modalities. In this context, the aim of this review is to discuss current scientific innovations, technical challenges, and prospective strategies in the development of IVUS-based multi-modality intravascular imaging systems aimed at assessing atherosclerotic plaque vulnerability. PMID:26400676

The Incidence of Intravascular Needle Entrance during Inferior Alveolar Nerve Block Injection.

PubMed

Taghavi Zenouz, Ali; Ebrahimi, Hooman; Mahdipour, Masoumeh; Pourshahidi, Sara; Amini, Parisa; Vatankhah, Mahdi

2008-01-01

Dentists administer thousands of local anesthetic injections every day. Injection to a highly vascular area such as pterygomandibular space during an inferior alveolar nerve block has a high risk of intravascular needle entrance. Accidental intravascular injection of local anesthetic agent with vasoconstrictor may result in cardiovascular and central nervous system toxicity, as well as tachycardia and hypertension. There are reports that indicate aspiration is not performed in every injection. The aim of the present study was to assess the incidence of intravascular needle entrance in inferior alveolar nerve block injections. Three experienced oral and maxillofacial surgeons performed 359 inferior alveolar nerve block injections using direct or indirect techniques, and reported the results of aspiration. Aspirable syringes and 27 gauge long needles were used, and the method of aspiration was similar in all cases. Data were analyzed using t-test. 15.3% of inferior alveolar nerve block injections were aspiration positive. Intravascular needle entrance was seen in 14.2% of cases using direct and 23.3% of cases using indirect block injection techniques. Of all injections, 15.8% were intravascular on the right side and 14.8% were intravascular on the left. There were no statistically significant differences between direct or indirect block injection techniques (P = 0.127) and between right and left injection sites (P = 0.778). According to our findings, the incidence of intravascular needle entrance during inferior alveolar nerve block injection was relatively high. It seems that technique and maneuver of injection have no considerable effect in incidence of intravascular needle entrance.

The Incidence of Intravascular Needle Entrance during Inferior Alveolar Nerve Block Injection

PubMed Central

Taghavi Zenouz, Ali; Ebrahimi, Hooman; Mahdipour, Masoumeh; Pourshahidi, Sara; Amini, Parisa; Vatankhah, Mahdi

2008-01-01

Background and aims Dentists administer thousands of local anesthetic injections every day. Injection to a highly vascular area such as pterygomandibular space during an inferior alveolar nerve block has a high risk of intravascular needle entrance. Accidental intravascular injection of local anesthetic agent with vasoconstrictor may result in cardiovascular and central nervous system toxicity, as well as tachycardia and hypertension. There are reports that indicate aspiration is not performed in every injection. The aim of the present study was to assess the incidence of intravascular needle entrance in inferior alveolar nerve block injections. Materials and methods Three experienced oral and maxillofacial surgeons performed 359 inferior alveolar nerve block injections using direct or indirect techniques, and reported the results of aspiration. Aspirable syringes and 27 gauge long needles were used, and the method of aspiration was similar in all cases. Data were analyzed using t-test. Results 15.3% of inferior alveolar nerve block injections were aspiration positive. Intravascular needle entrance was seen in 14.2% of cases using direct and 23.3% of cases using indirect block injection techniques. Of all injections, 15.8% were intravascular on the right side and 14.8% were intravascular on the left. There were no statistically significant differences between direct or indirect block injection techniques (P = 0.127) and between right and left injection sites (P = 0.778). Conclusion According to our findings, the incidence of intravascular needle entrance during inferior alveolar nerve block injection was relatively high. It seems that technique and maneuver of injection have no considerable effect in incidence of intravascular needle entrance. PMID:23285329

Whitacre Needle Reduces the Incidence of Intravascular Uptake in Lumbar Transforaminal Epidural Steroid Injections.

PubMed

Hong, JiHee; Jung, Sungwon; Chang, Hyuckwon

2015-01-01

Transforaminal epidural steroid injection (TFESI) is a commonly used interventional pain management procedures to treat radicular leg pain. Although most reported complications of TFESI are minor, serious morbidity has also been demonstrated including spinal cord infarction, paraplegia, and quadriparesis. Suggested mechanisms include direct vascular injury or intravascular injection of particulate steroid. We compared 2 different needle types, Whitacre and Quincke type needles, with regard to intravascular injection rate with total procedure time and the amount of radiation during lumbar TFESI. Prospective, randomized trial. An interventional pain management practice in South Korea. After Institutional Review Board approval, 149 patients undergoing lumbar TFESI for radicular leg pain were randomly assigned to one of 2 needle groups (Whitacre needle or Quincke type needle). After final confirmation of intravascular injection with digital subtraction angiography, total procedure time and amount of radiation exposure during TFESI were measured. The overall incidence of intravascular injection was 10.4% (28/269). We analyzed the overall incidence of intravascular injection according to the 2 different needle types. The incidence of intravascular injection of the Whitacre needle was 5.4% (8/146), whereas the incidence of intravascular injection of the Quincke needle was 16.2% (20/123). Total procedure time and amount of radiation required to complete the TFESI in the Whitacre and Quincke needle groups was 168.4 ± 57.9 (seconds) and 33.4 ± 15.9 (cGy/cm2), 131.9 ± 46.0 (seconds) and 33.2 ± 15.8 (cGy/cm2), respectively. The physician who performed the TFESI was not blinded to the type of needle for detecting intravascular injection. This study was focused on lumbar TFESI, however, most TFESIs are performed at the L4-5 or L5-S1 level. The Whitacre needle had the benefit of reducing the incidence of intravascular injection with minimal differences in technical difficulties and the amount of radiation exposure during lumbar TFESI.

A simple diagnostic test to confirm correct intravascular placement of peripheral catheters in order to avoid extravasation.

PubMed

Keidan, Ilan; Sidi, Avner; Ben-Menachem, Erez; Derazne, Estela; Berkenstadt, Haim

2015-11-01

Intravenous catheters are ubiquitous among modern medical management of patients, yet misplaced or tissued cannulas can result in serious iatrogenic injury due to infiltration or extravasation of injectate. Prevention is difficult, and currently few reliable tests exist to confirm intravascular placement of catheters in awake spontaneously breathing patients. Twenty conscious spontaneously breathing healthy volunteers were injected with 50 mL normal saline and 50 mL 4.2%, or 50 mL 2.1%, or 20 mL 4.2% sodium bicarbonate in a random order. A blinded anesthetist observed continuous sampling of exhaled carbon dioxide and was asked to differentiate between the sodium bicarbonate and saline injections. Peak increase in measured exhaled carbon dioxide was also calculated. Exhaled carbon dioxide increased significantly in participants injected with intravenous sodium bicarbonate. Mean peak increase was 7.4 mm Hg (±2.1 mm Hg) for 50 mL 4.2% sodium bicarbonate, 4.7 mm Hg (±2.5 mm Hg) for 20 mL 4.2% sodium bicarbonate, and 3.5 mm Hg (±1. 8 mm Hg) for 50 mL 2.1% sodium bicarbonate. The blinded observer correctly identified the injection as sodium bicarbonate or normal saline in every instance. Intravenous injection of dilute sodium bicarbonate with exhaled carbon dioxide monitoring reliably confirms correct intravascular placement of a catheter. A transient increase of exhaled carbon dioxide by 10% or more is an objective and reliable confirmation of intravascular location of the catheter. We recommend using 20 mL of 4.2% sodium bicarbonate to minimize the mEq dose of sodium bicarbonate required. Copyright © 2015 Elsevier Inc. All rights reserved.

Tissue velocity imaging of coronary artery by rotating-type intravascular ultrasound.

PubMed

Saijo, Yoshifumi; Tanaka, Akira; Owada, Naoki; Akino, Yoshihisa; Nitta, Shinichi

2004-04-01

Intravascular ultrasound (IVUS) provides not only the dimensions of coronary artery but the information of tissue components. In catheterization laboratory, soft and hard plaques are classified by visual inspection of echo intensity. So-called soft plaque contains lipid core or thrombus and it is believed to be more vulnerable than a hard plaque. However, it is not simple to analyze the echo signals quantitatively. When we look at a reflection signal, the intensity is affected by the distance of the object, the medium between transducer and objects and the fluctuation caused by rotation of IVUS probe. The time of flight is also affected by the sound speed of the medium and Doppler shift caused by tissue motion but usually those can be neglected. Thus, the analysis of RF signal in time domain can be more quantitative than intensity of RF signal. In the present study, a novel imaging technique called "intravascular tissue velocity imaging" was developed for searching a vulnerable plaque. Radio-frequency (RF) signal from a clinically used IVUS apparatus was digitized at 500 MSa/s and stored in a workstation. First, non-uniform rotation was corrected by maximizing the correlation coefficient of circumferential RF signal distribution in two consecutive frames. Then, the correlation and displacement were calculated by analyzing the radial difference of RF signal. Tissue velocity was determined by the displacement and the frame rate. The correlation image of normal and atherosclerotic coronary arteries clearly showed the internal and external borders of arterial wall. Soft plaque with low echo area in the intima showed high velocity while the calcified lesion showed the very low tissue velocity. This technique provides important information on tissue character of coronary artery.

Reduction of exit-site infections of tunnelled intravascular catheters among neutropenic patients by sustained-release chlorhexidine dressings: results from a prospective randomized controlled trial.

PubMed

Chambers, S T; Sanders, J; Patton, W N; Ganly, P; Birch, M; Crump, J A; Spearing, R L

2005-09-01

Exit-site and tunnel infections of tunnelled central intravascular catheters are a frequent source of morbidity among neutropenic patients and may necessitate catheter removal. They require antimicrobial therapy that increases healthcare costs and is associated with adverse drug reactions. A prospective randomized clinical trial was conducted among adult patients undergoing chemotherapy in a haematology unit. Tunnelled intravascular catheters were randomized to receive the control of a standard dressing regimen as recommended by the British Committee for Standards in Haematology, or to receive the intervention of a sustained-release chlorhexidine dressing. Follow-up data were available in 112 of 114 tunnelled intravascular catheters which were randomized. Exit-site or combined exit-site/tunnel infections occurred in 23 (43%) of 54 catheters in the control group, and five (9%) of 58 catheters in the intervention group [odds ratio (OR) for intervention group compared with control group =0.13, 95% confidence intervals (CI) 0.04-0.37, P<0.001]. More tunnelled intravascular catheters were prematurely removed from the control group than the intervention group for documented infections [20/54 (37%) vs 6/58 (10%), OR=0.20, 95%CI 0.53-0.07]. However, there was no difference in the numbers of tunnelled intravascular catheters removed for all proven and suspected intravascular catheter-related infections [21/54 (39%) vs 19/58 (33%)], or in the time to removal of catheters for any reason other than death or end of treatment for underlying disease. Thus chlorhexidine dressings reduced the incidence of exit-site/tunnel infections of indwelling tunnelled intravascular catheters without prolonging catheter survival in neutropenic patients, and could be considered as part of the routine management of indwelling tunnelled intravascular catheters among neutropenic patients.

Fast integrated intravascular photoacoustic/ultrasound catheter

NASA Astrophysics Data System (ADS)

Choi, Changhoon; Cho, Seunghee; Kim, Taehoon; Park, Sungjo; Park, Hyoeun; Kim, Jinmoo; Lee, Seunghoon; Kang, Yeonsu; Jang, Kiyuk; Kim, Chulhong

2016-03-01

In cardiology, a vulnerable plaque is considered to be a key subject because it is strongly related to atherosclerosis and acute myocardial infarction. Because conventional intravascular imaging devices exhibit several limitations with regard to vulnerable plaque detection, the need for an effective lipid imaging modality has been continuously suggested. Photoacoustic (PA) imaging is a medical imaging technique with a high level of ultrasound (US) resolution and strong optical contrast. In this study, we successfully developed an integrated intravascular photoacoustic/ultrasound (IV-PAUS) imaging system with a catheter diameter of 1.2 mm for lipid-rich atherosclerosis imaging. An Nd:YAG pulsed laser with an excitation wavelength of 1064 nm was utilized. IV-PAUS offers 5-mm depth penetration and axial and lateral PA imaging resolutions of 94 μm and 203 μm, respectively, as determined by imaging a 6-μm carbon fiber. We initially obtained 3-dimensional (3D) co-registered PA/US images of metal stents. Subsequently, we successfully obtained 3D coregistered PA/US ex vivo images using an iliac artery from a rabbit atherosclerosis model. Accordingly, lipid-rich plaques were sufficiently differentiated from normal tissue in the ex vivo experiment. We validated these findings histologically to confirm the lipid content.

21 CFR 882.5150 - Intravascular occluding catheter.

Code of Federal Regulations, 2011 CFR

2011-04-01

... 21 Food and Drugs 8 2011-04-01 2011-04-01 false Intravascular occluding catheter. 882.5150 Section 882.5150 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES NEUROLOGICAL DEVICES Neurological Therapeutic Devices § 882.5150 Intravascular...

21 CFR 882.5150 - Intravascular occluding catheter.

Code of Federal Regulations, 2010 CFR

2010-04-01

... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Intravascular occluding catheter. 882.5150 Section 882.5150 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES NEUROLOGICAL DEVICES Neurological Therapeutic Devices § 882.5150 Intravascular...

Tuning and amplification strategies for intravascular imaging coils.

PubMed

Yak, Nicolas; Anderson, Kevan J T; Wright, Graham A

2012-11-01

The manufacturing of intravascular imaging coils poses several challenges. Due to their size, it can be difficult to incorporate local matching networks and signal amplifiers. The goal of this study is to investigate tuning and amplification strategies for intravascular coils and to assess the signal-to-noise benefits of incorporating a matching network and/or miniature amplifier into catheter-based intravascular imaging devices at various locations in the signal chain. The results suggest that the use of a low-noise amplifier close to the receiving coil enables the use of miniature coaxial cables to be used despite being noisy. Moreover, an improvement in the signal-to-noise ratio of over 75% is presented over conventional intravascular coil configurations where the matching circuit and low-noise amplifier are placed at the proximal end. Therefore, designing devices for intravascular applications capable of generating high signal-to-noise ratio images becomes more feasible, also allowing for significant reductions in scan time. Copyright © 2011 Wiley Periodicals, Inc.

21 CFR 880.5200 - Intravascular catheter.

Code of Federal Regulations, 2010 CFR

2010-04-01

... Devices § 880.5200 Intravascular catheter. (a) Identification. An intravascular catheter is a device that consists of a slender tube and any necessary connecting fittings and that is inserted into the patient's vascular system for short term use (less than 30 days) to sample blood, monitor blood pressure, or...

78 FR 53773 - Select Updates for Non-Clinical Engineering Tests and Recommended Labeling for Intravascular...

Federal Register 2010, 2011, 2012, 2013, 2014

2013-08-30

...] Select Updates for Non-Clinical Engineering Tests and Recommended Labeling for Intravascular Stents and... Engineering Tests and Recommended Labeling for Intravascular Stents and Associated Delivery Systems.'' FDA has developed this guidance to inform the coronary and peripheral stent industry about selected updates to FDA's...

Intravascular OCT

NASA Astrophysics Data System (ADS)

Schmitt, Joseph M.; Adler, Desmond; Xu, Chenyang

Since the first coronary angioplasty was performed in the late 1970s, imaging has played a central role in percutaneous coronary intervention (PCI). Today more than three million PCI procedures are performed worldwide to expand narrowed arteries and to clear blood clots that can cause debilitating symptoms of myocardial ischemia or fatal heart attacks. Although X-ray angiography is still the workhorse imaging modality in the field of interventional cardiology, intravascular imaging has become an indispensable tool for guiding complex PCI procedures. Intravascular ultrasound (IVUS) and optical coherence tomography (OCT) are the two most commonly used catheter-based imaging technologies in coronary procedures. Since the first commercial intravascular OCT systems were introduced in Japan and the European Union in 2004 and in the United States in 2009, the application of intravascular OCT has grown rapidly [3, 15, 16].

A comparison of Quincke and Whitacre needles with respect to risk of intravascular uptake in S1 transforaminal epidural steroid injections: a randomized trial of 1376 cases.

PubMed

Shin, Jaehyuck; Kim, Yong Chul; Lee, Sang Chul; Kim, Jae Hun

2013-11-01

Transforaminal epidural steroid injection (TFESI) is a useful treatment modality for pain management. Most complications of TFESI are minor and transient. However, there is a risk of serious complications such as nerve injury, spinal cord infarct, or paraplegia. Some of the risks are related to direct injury to the vessel or intravascular injection of the particulate steroid. We prospectively tested the hypothesis that the intravascular injection rate of the Whitacre needle is lower than that of the Quincke needle during TFESI. This study was a randomized trial of 1376 TFESIs at the S1 level. We collected data of age, gender, height, weight, laterality (right/left), history of lumbosacral spine operation, history of appropriate interval discontinuation of anticoagulation medicines, and underlying disease. During the S1 TFESI, intrasacral bone contact, a blood aspiration test, and real-time fluoroscopy of the intravascular injection using contrast media were investigated. There were no significant differences in the intravascular injection rate with respect to age, gender, height, weight, hypertension, diabetes mellitus, laterality, history of lumbosacral spine operation, or history of appropriate interval discontinuation of anticoagulation medicines. Intravascular injection was significantly associated with a blood aspiration test (P < 0.001), needle tip type (P = 0.002), intrasacral bone contact (P < 0.001), and physicians (some P < 0.05). The use of Quincke needles and intrasacral bone contact increased the rate of intravascular injection. To reduce the risk of intravascular injection, the use of Whitacre needles without intrasacral bone contact may be a safer and more effective approach.

Intravascular lymphoma with a gastric submucosal tumor.

PubMed

Sawahara, Hiroaki; Iwamuro, Masaya; Ito, Mamoru; Nose, Soichiro; Nishimura, Mamoru; Okada, Hiroyuki

A 75-year-old man was admitted to our hospital for further examination of swollen lymph nodes and a possible gastric submucosal tumor. He had persistent fever and anorexia. Blood examination showed anemia, thrombocytopenia, and elevated lactate dehydrogenase and soluble interleukin 2 receptor levels. Swollen lymph nodes and splenomegaly were evident on computed tomography, and the submucosal tumor was revealed by esophagogastric endoscopy. Cervical lymph node biopsy and endoscopic biopsy were performed, which revealed a diagnosis of intravascular lymphoma. In Asian countries, patients with intravascular lymphoma often have hemophagocytic syndrome without lesions of the central nervous system or skin, which is called the Asian variant of intravascular lymphoma. In this case, the patient had no indicative lesions and had no evidence of the hemophagocytic syndrome. He also had lymph node swelling and a gastric submucosal tumor, which are rare in intravascular lymphoma. The patient was treated with chemotherapy (R-CHOP;rituximab-cyclophosphamide, doxorubicin, vincristine, and prednisolone), and complete response was demonstrated (based on the Response Evaluation Criteria for Solid Tumours [RECIST] guideline). In cases of possible intravascular lymphoma, gastrointestinal endoscopy and biopsy should be considered because they are a useful diagnostic strategy.

Estimation of blood flow heterogeneity in human skeletal muscle using intravascular tracer data: importance for modeling transcapillary exchange.

PubMed

Vicini, P; Bonadonna, R C; Lehtovirta, M; Groop, L C; Cobelli, C

1998-01-01

Distributed models of blood-tissue exchange are widely used to measure kinetic events of various solutes from multiple tracer dilution experiments. Their use requires, however, a careful description of blood flow heterogeneity along the capillary bed. Since they have mostly been applied in animal studies, direct measurement of the heterogeneity distribution was possible, e.g., with the invasive microsphere method. Here we apply distributed modeling to a dual tracer experiment in humans, performed using an intravascular (indocyanine green dye, subject to distribution along the vascular tree and confined to the capillary bed) and an extracellular ([3H]-D-mannitol, tracing passive transcapillary transfer across the capillary membrane in the interstitial fluid) tracer. The goal is to measure relevant parameters of transcapillary exchange in human skeletal muscle. We show that assuming an accurate description of blood flow heterogeneity is crucial for modeling, and in particular that assuming for skeletal muscle the well-studied cardiac muscle blood flow heterogeneity is inappropriate. The same reason prevents the use of the common method of estimating the input function of the distributed model via deconvolution, which assumes a known blood flow heterogeneity, either defined from literature or measured, when possible. We present a novel approach for the estimation of blood flow heterogeneity in each individual from the intravascular tracer data. When this newly estimated blood flow heterogeneity is used, a more satisfactory model fit is obtained and it is possible to reliably measure parameters of capillary membrane permeability-surface product and interstitial fluid volume describing transcapillary transfer in vivo.

The intravascular volume effect of Ringer's lactate is below 20%: a prospective study in humans.

PubMed

Jacob, Matthias; Chappell, Daniel; Hofmann-Kiefer, Klaus; Helfen, Tobias; Schuelke, Anna; Jacob, Barbara; Burges, Alexander; Conzen, Peter; Rehm, Markus

2012-05-16

Isotonic crystalloids play a central role in perioperative fluid management. Isooncotic preparations of colloids (for example, human albumin or hydroxyethyl starch) remain nearly completely intravascular when infused to compensate for acute blood losses. Recent data were interpreted to indicate a comparable intravascular volume effect for crystalloids, challenging the occasionally suggested advantage of using colloids to treat hypovolemia. General physiological knowledge and clinical experience, however, suggest otherwise. In a prospective study, double-tracer blood volume measurements were performed before and after intended normovolemic hemodilution in ten female adults, simultaneously substituting the three-fold amount of withdrawn blood with Ringer's lactate. Any originated deficits were substituted with half the volume of 20% human albumin, followed by a further assessment of blood volume. To assess significance between the measurements, repeated measures analysis of variance (ANOVA) according to Fisher were performed. If significant results were shown, paired t tests (according to Student) for the singular measurements were taken. P < 0.05 was considered to be significant. A total of 1,097 ± 285 ml of whole blood were withdrawn (641 ± 155 ml/m(2) body surface area) and simultaneously replaced by 3,430 ± 806 ml of Ringer's lactate. All patients showed a significant decrease in blood volume after hemodilution (-459 ± 185 ml; P < 0.05) that did not involve relevant hemodynamical changes, and a significant increase in interstitial water content (+2,157 ± 606 ml; P < 0.05). The volume effect of Ringer's lactate was 17 ± 10%. The infusion of 245 ± 64 ml of 20% human albumin in this situation restored blood volume back to baseline values, the volume effect being 184 ± 63%. Substitution of isolated intravascular deficits in cardiopulmonary healthy adults with the three-fold amount of Ringer's lactate impedes maintenance of intravascular normovolemia. The main side effect was an impressive interstitial fluid accumulation, which was partly restored by the intravenous infusion of 20% human albumin. We recommend to substitute the five-fold amount of crystalloids or to use an isooncotic preparation in the face of acute bleeding in patients where edema prevention might be advantageous.

Targeted Near-Infrared Fluorescence Imaging of Atherosclerosis: Clinical and Intracoronary Evaluation of Indocyanine Green.

PubMed

Verjans, Johan W; Osborn, Eric A; Ughi, Giovanni J; Calfon Press, Marcella A; Hamidi, Ehsan; Antoniadis, Antonios P; Papafaklis, Michail I; Conrad, Mark F; Libby, Peter; Stone, Peter H; Cambria, Richard P; Tearney, Guillermo J; Jaffer, Farouc A

2016-09-01

This study sought to determine whether indocyanine green (ICG)-enhanced near-infrared fluorescence (NIRF) imaging can illuminate high-risk histologic plaque features of human carotid atherosclerosis, and in coronary atheroma of living swine, using intravascular NIRF-optical coherence tomography (OCT) imaging. New translatable imaging approaches are needed to identify high-risk biological signatures of atheroma. ICG is a U.S. Food and Drug Administration-approved NIRF imaging agent that experimentally targets plaque macrophages and lipid in areas of enhanced endothelial permeability. However, it is unknown whether ICG can target atheroma in patients. Eight patients were enrolled in the BRIGHT-CEA (Indocyanine Green Fluorescence Uptake in Human Carotid Artery Plaque) trial. Five patients were injected intravenously with ICG 99 ± 25 min before clinically indicated carotid endarterectomy. Three saline-injected endarterectomy patients served as control subjects. Excised plaques underwent analysis by intravascular NIRF-OCT, reflectance imaging, microscopy, and histopathology. Next, following ICG intravenous injection, in vivo intracoronary NIRF-OCT and intravascular ultrasound imaged 3 atheroma-bearing coronary arteries of a diabetic, cholesterol-fed swine. ICG was well tolerated; no adverse clinical events occurred up to 30 days post-injection. Multimodal NIRF imaging including intravascular NIRF-OCT revealed that ICG accumulated in all endarterectomy specimens. Plaques from saline-injected control patients exhibited minimal NIRF signal. In the swine experiment, intracoronary NIRF-OCT identified ICG uptake in all intravascular ultrasound-identified plaques in vivo. On detailed microscopic evaluation, ICG localized to plaque areas exhibiting impaired endothelial integrity, including disrupted fibrous caps, and within areas of neovascularization. Within human plaque areas of endothelial abnormality, ICG was spatially related to localized zones of plaque macrophages and lipid, and, notably, intraplaque hemorrhage. This study demonstrates that ICG targets human plaques exhibiting endothelial abnormalities and provides new insights into its targeting mechanisms in clinical and experimental atheroma. Intracoronary NIRF-OCT of ICG may offer a novel, clinically translatable approach to image pathobiological aspects of coronary atherosclerosis. (Indocyanine Green Fluorescence Uptake in Human Carotid Artery Plaque [BRIGHT-CEA]; NCT01873716). Copyright © 2016 American College of Cardiology Foundation. Published by Elsevier Inc. All rights reserved.

Intravascular Neural Interface with Nanowire Electrode

PubMed Central

Watanabe, Hirobumi; Takahashi, Hirokazu; Nakao, Masayuki; Walton, Kerry; Llinás, Rodolfo R.

2010-01-01

Summary A minimally invasive electrical recording and stimulating technique capable of simultaneously monitoring the activity of a significant number (e.g., 103 to 104) of neurons is an absolute prerequisite in developing an effective brain–machine interface. Although there are many excellent methodologies for recording single or multiple neurons, there has been no methodology for accessing large numbers of cells in a behaving experimental animal or human individual. Brain vascular parenchyma is a promising candidate for addressing this problem. It has been proposed [1, 2] that a multitude of nanowire electrodes introduced into the central nervous system through the vascular system to address any brain area may be a possible solution. In this study we implement a design for such microcatheter for ex vivo experiments. Using Wollaston platinum wire, we design a submicron-scale electrode and develop a fabrication method. We then evaluate the mechanical properties of the electrode in a flow when passing through the intricacies of the capillary bed in ex vivo Xenopus laevis experiments. Furthermore, we demonstrate the feasibility of intravascular recording in the spinal cord of Xenopus laevis. PMID:21572940

Application of Near Infrared Spectroscopy, Intravascular Ultrasound and the Coronary Calcium Score to Predict Adverse Coronary Events

DTIC Science & Technology

2015-10-01

planned. 15. SUBJECT TERMS coronary artery disease , near infrared spectroscopy, calcium scoring, intravascular ultrasound 16. SECURIY CLASSIFICATION OF...Award Number: W81XWH-11-1-0831 TITLE: Application of Near Infrared Spectroscopy, Intravascular Ultrasound and the Coronary Calcium Score to...Predict Adverse Coronary Events PRINCIPAL INVESTIGATOR: Dr. Charles Lambert CONTRACTING ORGANIZATION: University Community Hospital Tampa, FL 33613

Intraoperative intravascular volume optimisation and length of hospital stay after repair of proximal femoral fracture: randomised controlled trial.

PubMed Central

Sinclair, S.; James, S.; Singer, M.

1997-01-01

OBJECTIVES: To assess whether intraoperative intravascular volume optimisation improves outcome and shortens hospital stay after repair of proximal femoral fracture. DESIGN: Prospective, randomised controlled trial comparing conventional intraoperative fluid management with repeated colloid fluid challenges monitored by oesophageal Doppler ultrasonography to maintain maximal stroke volume throughout the operative period. SETTING: Teaching hospital, London. SUBJECTS: 40 patients undergoing repair of proximal femoral fracture under general anaesthesia. INTERVENTIONS: Patients were randomly assigned to receive either conventional intraoperative fluid management (control patients) or additional repeated colloid fluid challenges with oesophageal Doppler ultrasonography used to maintain maximal stroke volume throughout the operative period (protocol patients). MAIN OUTCOME MEASURES: Time declared medically fit for hospital discharge, duration of hospital stay (in acute bed; in acute plus long stay bed), mortality, perioperative haemodynamic changes. RESULTS: Intraoperative intravascular fluid loading produced significantly greater changes in stroke volume (median 15 ml (95% confidence interval 10 to 21 ml)) and cardiac output (1.2 l/min (0.1 to 2.3 l/min)) than in the conventionally managed group (-5 ml (-10 to 1 ml) and -0.4 l/min (-1.0 to 0.2 l/min)) (P < 0.001 and P < 0.05, respectively). One protocol patient and two control patients died in hospital. In the survivors, postoperative recovery was significantly faster in the protocol patients, with shorter times to being declared medically fit for discharge (median 10 (9 to 15) days v 15 (11 to 40) days, P < 0.05) and a 39% reduction in hospital stay (12 (8 to 13) days v 20 (10 to 61) days, P < 0.05). CONCLUSIONS: Proximal femoral fracture repair constitutes surgery in a high risk population. Intraoperative intravascular volume loading to optimal stroke volume resulted in a more rapid postoperative recovery and a significantly reduced hospital stay. PMID:9361539

Small-Interfering RNA–Eluting Surfaces as a Novel Concept for Intravascular Local Gene Silencing

PubMed Central

Nolte, Andrea; Walker, Tobias; Schneider, Martina; Kray, Oya; Avci-Adali, Meltem; Ziemer, Gerhard; Wendel, Hans Peter

2011-01-01

New drug-eluting stent (DES) methods have recently been demonstrated to improve outcomes of intravascular interventions. A novel technique is the design of gene-silencing stents that elute specific small-interfering RNAs (siRNAs) for better vascular wall regeneration. Although siRNAs used to alter gene expression have surpassed expectations in in vitro experiments, the functional and local delivery of siRNAs is still the major obstacle for the in vivo application of RNA interference. In this preliminary in vitro study we investigated a surface-immobilized siRNA delivery technique that would be readily adaptable for local intravascular applications in vivo. The transfection potency of gelatin coatings consisting of a specific siRNA complexed with polyethylenimine (PEI) was examined in primary human endothelial cells by flow cytometry and quantitative real-time polymerase chain reaction. Several media conditions, such as the presence or absence of serum during cultivation, were investigated. Furthermore, different siRNA and PEI amounts, as well as nitrogen/phosphate ratios, were tested for their transfection efficiency. Gelatin coatings consisting of PEI and siRNA against an exemplary endothelial adhesion molecule receptor achieved a significant knockdown of around 70%. The transfection efficiency of the coatings was not influenced by the presence of serum. The results of this preliminary study support the expectation that this novel coating may be favorable for local in vivo gene silencing (for example, when immobilized on stents or balloons for percutanous transluminal coronary angioplasty). However, further animal experiments are needed to confirm the translation into clinical practice. This intriguing technology leads the way to more sophisticated and individualized coatings for the post-DES era, toward silencing of genes involved in the pathway of intimal hyperplasia. PMID:21792480

Virtual angioscopic visualization and analysis of coronary aneurysms using intravascular ultrasound images

NASA Astrophysics Data System (ADS)

Ayeni, Tina A.; Holmes, David R., III; Robb, Richard A.

2001-05-01

Kawasaki Disease is an inflammatory illness of young children that can seriously affect the cardiovascular system. The disease may cause coronary artery aneurysms, a thinning and dilation of the arterial wall when the wall is weakened by disease. Such aneurysms significantly increase the risk of rupture of the arterial wall, an event from which few patients survive. Due to the largely asymptotic nature of coronary aneurysms, diagnosis must be timely and accurate in order for treatment to be effective. Currently, aneurysms are detected primarily using X-ray angiography, MRI, and CT images. Increased insight into the disease and its effects on the arterial wall can be gained by multi-dimensional computerized visualization and quantitative analysis of diagnostic images made possible by the techniques of intravascular imaging and virtual endoscopy. Intravascular ultrasound images (IVUS) of a coronary artery exhibiting aneurysms were acquired from a patient with Kawasaki Disease. The disease is characterized by low luminescent in the IVUS images. Image segmentation of the abnormal, prominent anechoic regions branching from the lumen and originating within other layers of the arterial wall was performed and each region defined as a separate object. An object segmentation map was generated and used in perspective rendering of the original image volume set at successive locations along the length of the arterial segment, producing a 'fly-through' of the interior of the artery. The diseased region (aneurysm) of the wall was well defined by the differences in luminal size and by differences in appearance of the arterial wall shape observed during virtual angioscopic fly-throughs. Erosions of the endovascular surface caused pronounced horizontal and vertical ballooning of the lumen. Minute cracks within the unaffected luminal areas revealed possible early development of an aneurysm on the contralateral wall, originating in the medial section of the artery and spreading outward toward the lumen.

A NEW STRAIN OF TRANSMISSIBLE LEUCEMIA IN FOWLS (STRAIN H).

PubMed

Ellermann, V

1921-03-31

1. A new strain of fowl leucosis has been transmitted through twelve generations of fowls. 2. An increase in virulence was observed during its passage. This was shown in a shortening of the interval between inoculation and death. The increase in virulence does not affect the number of successful inoculations, which remains approximately constant in from 20 to 40 per cent of the birds employed. 3. As with former strains, the disease manifests itself in various forms; i.e., myeloid and intravascular lymphoid types. A single lymphatic case was observed. 4. In several intravascular cases a diminution in the hemolytic power of the serum was established. This phenomenon was absent in a number of myeloid cases. 5. Active immunization cannot be produced by means of the subcutaneous injection of virulent material. 6. The finding of previous experiments that the virus is filterable has been confirmed. 7. The inoculation of human leucemic material into fowls gave negative results.

Wound shock: a history of its study and treatment by military surgeons.

PubMed

Hardaway, Robert M

2004-04-01

The treatment of wounds has received considerable attention from the time of the Trojan War. However, it was not until the American Civil War that shock was described as an entity distinct from the wounds themselves and that efforts were directed at more than just treatment of the wound. The need for fluid resuscitation in the treatment of hemorrhagic shock was first recognized in the Spanish American War, as was the association of sepsis with shock. World War I showed the need for blood in the treatment of "wound shock," a lesson that had to be relearned in World War II through bitter experience. Studies in the Korean War described the concept of disseminated intravascular coagulation and multiple organ failure, and the existence of disseminated intravascular coagulation was confirmed by studies in Vietnam. The treatment of hemorrhagic shock is now very effective, but the treatment of traumatic and septic shock remains unsatisfactory.

Intravascular lymphoma involving the central and peripheral nervous systems in a dog.

PubMed

Bush, William W; Throop, Juliene L; McManus, Patricia M; Kapatkin, Amy S; Vite, Charles H; Van Winkle, Tom J

2003-01-01

A 5-year-old, castrated male mixed-breed dog was presented for paraparesis, ataxia, hyperesthesia, and thrombocytopenia of 5 months' duration and recurrent seizures during the preceding 2 weeks. Multifocal neurological, ophthalmological, pulmonary, and cardiac diseases were identified. Magnetic resonance imaging and cerebrospinal fluid analysis supported a tentative diagnosis of neoplastic or inflammatory disease. A computed tomography-guided biopsy provided both cytopathological and histopathological evidence of intravascular lymphoma. The disease progressed despite chemotherapy with prednisone, L-asparginase, and vincristine. Postmortem histopathological examinations suggested intravascular lymphoma in the central and peripheral nervous systems as well as in multiple other organ systems. This is the first description of an antemortem diagnosis and treatment of intravascular lymphoma involving the central nervous system of a dog.

Currently available methodologies for the processing of intravascular ultrasound and optical coherence tomography images.

PubMed

Athanasiou, Lambros; Sakellarios, Antonis I; Bourantas, Christos V; Tsirka, Georgia; Siogkas, Panagiotis; Exarchos, Themis P; Naka, Katerina K; Michalis, Lampros K; Fotiadis, Dimitrios I

2014-07-01

Optical coherence tomography and intravascular ultrasound are the most widely used methodologies in clinical practice as they provide high resolution cross-sectional images that allow comprehensive visualization of the lumen and plaque morphology. Several methods have been developed in recent years to process the output of these imaging modalities, which allow fast, reliable and reproducible detection of the luminal borders and characterization of plaque composition. These methods have proven useful in the study of the atherosclerotic process as they have facilitated analysis of a vast amount of data. This review presents currently available intravascular ultrasound and optical coherence tomography processing methodologies for segmenting and characterizing the plaque area, highlighting their advantages and disadvantages, and discusses the future trends in intravascular imaging.

A Close Cut: A Technical Report of Endovascular Removal of a Penetrating Intravascular Foreign Body after a Lawn Mowing Injury

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

Tapping, C. R.; Gallo, A.; Silva, R. J. De

2012-12-15

We present a case of endovascular retrieval of a penetrating foreign body that was originally lodged in the mediastinum and then migrated to the hepatic vein. The steel nail entered the thorax and traversed the left lung causing a pneumothorax. The patient underwent a thoracotomy, but the foreign body had migrated from its original mediastinal position. A postsurgical CT showed that the object was below the right hemidiaphragm. Diagnostic venogram demonstrated that the object was in the main hepatic vein. Using a double-snare technique, the object was safely and successfully removed from the hepatic vein via the right common femoralmore » vein.« less

An intravascular loopless monopole antenna for vessel wall MR imaging at 3.0 T.

PubMed

Yuan, Hongyang; Lv, Xing; Ma, Xiaohai; Zhang, Rui; Fu, Youyi; Yang, Xuedong; Wang, Xiaoying; Zhang, Zhaoqi; Zhang, Jue; Fang, Jing

2013-01-01

The purpose of this study was to develop a novel intravascular loopless monopole antenna (ILMA) design specifically for imaging of small vessel walls. The ILMA consisted of an unshielded, low-friction guide wire and a tuning/matching box. The material of the guide wire was nitinol and it was coated with polyurethane. Because the guide wire was unshielded, it could be made thinner than the coaxial cable-based loopless intravascular antenna design. The material of the box was aluminum. In this study, the diameter of the guide wire was 0.5 mm and the length was 58.7 mm. The ILMA was used as a receiving antenna and body coil for transmission. To verify the feasibility of the ILMA, in vitro and in vivo experiments were performed on a 3.0-T magnetic resonance (MR) scanner. In vitro tests using the ILMA indicated that the proposed design could be used to image target vessel walls with a spatial resolution of 313 μm at the frequency coding direction and more than 100 mm of longitudinal coverage. In vivo tests demonstrated that the images showed the vessel walls clearly by using the ILMA and also indicated that the ILMA could be used for small vessels. The proposed antenna may therefore be utilized to promote MR-based diagnoses and therapeutic solutions for cardiovascular atherosclerotic diseases. Copyright © 2013 Elsevier Inc. All rights reserved.

Acute lipophilicity-dependent effect of intravascular simvastatin in the early phase of focal cerebral ischemia.

PubMed

Beretta, S; Pastori, C; Sala, G; Piazza, F; Ferrarese, C; Cattalini, A; de Curtis, M; Librizzi, L

2011-05-01

The acute effects of simvastatin lactone (lipophilic) and simvastatin acid (hydrophilic) on transient focal ischemia were assessed using the isolated guinea pig brain maintained in vitro by arterial perfusion. This new model of cerebral ischemia allows the assessment of the very early phase of the ischemic process, with the functional preservation of the vascular and neuronal compartments and the blood-brain barrier (bbb). The middle cerebral artery was transiently tied for 30 min followed by reperfusion for 60 min. Statins (nanomolar doses) were administered by intravascular continuous infusion starting 60 min before ischemia induction. Brain cortical activity and arterial vascular tone were continuously recorded. At the end of the experiment immunoreactivity for microtubule-associated protein 2 (MAP-2), expression of survival kinases (ERK and Akt) and total anti-oxidant capacity were assayed. Brains treated with simvastatin lactone showed i) reduced amplitude and delayed onset of ischemic depressions, ii) preservation of MAP-2 immunoreactivity, iii) activation of ERK signaling in the ischemic hemisphere and iv) increase in whole-brain anti-oxidant capacity. Treatment with the bbb-impermeable simvastatin acid was ineffective on the above-mentioned parameters. Vascular resistance recordings and Akt signaling were unchanged by any statin treatment. Our findings suggest that intravascular-delivered simvastatin exerts an acute lipophilicity-dependent protective effect in the early phase of cerebral ischemia. Copyright © 2011 Elsevier Ltd. All rights reserved.

Plasmodium falciparum cerebral malaria complicated by disseminated intravascular coagulation and symmetrical peripheral gangrene: case report and review.

PubMed

Liechti, M E; Zumsteg, V; Hatz, C F R; Herren, T

2003-09-01

The case of a 56-year-old female tourist who survived cerebral Plasmodium falciparum malaria with disseminated intravascular coagulation and symmetrical peripheral gangrene, ultimately requiring amputation of her left-sided fingertips and toes, is reported. While symmetrical peripheral gangrene has been described rarely in Asian, African, and American patients with Plasmodium falciparum malaria and disseminated intravascular coagulation, no such case has been reported in travelers returning from endemic areas.

Intravascular NK/T-cell lymphoma: a report of five cases with cutaneous manifestation from China.

PubMed

Wang, Lei; Chen, Siyuan; Ma, Han; Shi, Dongmei; Huang, Changzheng; Lu, Chun; Gao, Tianwen; Wang, Gang

2015-09-01

Intravascular lymphoma is a rare type of lymphoma that frequently affects the skin and is usually of B-cell origin. This lymphoma type is very rare and not recognized as a separate entity in the 2008 World Health Organization classification of hematopoietic and lymphoid tissue tumors. We reported five cases of intravascular NK/T cell lymphoma with cutaneous manifestation and reviewed 12 published cases involving Chinese patients with similar characteristics. All five patients were adults who exhibited red or brown patches or plaques on the lower extremities or trunk; four cases were associated with B symptoms; one case developed subsequent to a lymphoma on the face (possibly extranodal NK/T cell lymphoma, nasal type). Histopathologically, all patients exhibited abnormal, medium-sized intravascular lymphocytes in the dermis and subcutaneous tissues. All patients were positive for CD2, CD3ϵ, CD56 and cytotoxic proteins. All cases were Epstein-Barr virus (EBV) positive. Four of FIVE patients died of lymphoma within a few months of diagnosis. Intravascular NK/T-cell lymphoma is a rare highly aggressive and EBV-associated lymphoma that is prone to develop in Chinese patients. The relationship between intravascular NK/T-cell lymphoma and extranodal NK/T-cell lymphoma, nasal type, requires clarification. © 2015 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Acute intravascular hemolysis and methemoglobinemia following naphthalene ball poisoning.

PubMed

Kapoor, Rajan; Suresh, P; Barki, Satish; Mishra, Mayank; Garg, M K

2014-09-01

Naphthalene (C10H8) is a natural component of fossil fuels such as petroleum, diesel and coal. The common consumer products made from naphthalene are moth repellents, in the form of mothballs or crystals, and toilet deodorant blocks. Major toxic effects of naphthalene are due to precipitation of acute intravascular hemolysis. Very few cases of naphthalene poisoning and its effects have been reported from India. We report a case of accidental naphthalene poisoning, who presented with intravascular hemolysis and methemoglobinemia.

Fibrinopeptide A blood test

MedlinePlus

... problems with blood clotting such as disseminated intravascular coagulation ( DIC ). Certain types of leukemia are associated with ... be a sign of: Cellulitis DIC (disseminated intravascular coagulation) Leukemia at the time of diagnosis, during early ...

What Is Disseminated Intravascular Coagulation?

MedlinePlus

... leading to DIC. These diseases and conditions include: Sepsis (an infection in the bloodstream) Surgery and trauma ... intravascular coagulation (DIC). These diseases and conditions include: Sepsis (an infection in the bloodstream) Surgery and trauma ...

Intravascular laser therapy in different forms of lung diseases

NASA Astrophysics Data System (ADS)

Kirillov, M. N.; Reshetnikov, V. A.; Kazhekin, O. A.; Shepelenko, A. F.

1993-06-01

The potentions of laser intravascular therapy in elimination of pyogenic and inflammatory intoxication in cases of acute pneumonia, pyo-destructive diseases (including posttraumatic diseases) of the lungs are studied clinically.

Life-threatening urethral hemorrhage after placement of a Foley catheter in a patient with uroseptic disseminated intravascular coagulation due to chronic urinary retention induced by untreated benign prostatic hyperplasia.

PubMed

Ikegami, Yukihiro; Yoshida, Keisuke; Imaizumi, Tsuyoshi; Isosu, Tsuyoshi; Kurosawa, Shin; Murakawa, Masahiro

2016-10-01

A 77-year-old man with severe septic disseminated intravascular coagulation following urinary infection was transported to our hospital. He had developed urinary retention induced by untreated prostatic hyperplasia. Immediate drainage with a Foley catheter was successfully carried out, but the hematuria progressed to life-threatening hemorrhage. Complete hemostasis was impossible by surgical treatment because the tissue around the prostatic urethra was very fragile and hemorrhagic. Organized treatments (continuous hemodiafiltration combined with polymyxin-B immobilized fiber column hemoperfusion and systemic treatment with antibiotics and coagulation factors) were commenced soon after the operation. The patient eventually recovered from the septic disseminated intravascular coagulation. This case report illustrates the risk of placement of Foley catheters in patients with severe septic disseminated intravascular coagulation.

Evaluation of Intravascular Hemolysis With Erythrocyte Creatine in Patients With Aortic Stenosis.

PubMed

Sugiura, Tetsuro; Okumiya, Toshika; Kubo, Toru; Takeuchi, Hiroaki; Matsumura, Yoshihisa

2016-07-27

Chronic intravascular hemolysis has been identified in patients with cardiac valve prostheses, but only a few case reports have evaluated intravascular hemolysis in patients with native valvular heart disease. To detect intravascular hemolysis in patients with aortic stenosis, erythrocyte creatine was evaluated with hemodynamic indices obtained by echocardiography.Erythrocyte creatine, a marker of erythrocyte age, was assayed in 30 patients with aortic stenosis and 10 aged matched healthy volunteers. Peak flow velocity of the aortic valve was determined by continuous-wave Doppler echocardiography. Twenty of 30 patients with aortic stenosis had high erythrocyte creatine levels (> 1.8 µmol/g Hb) and erythrocyte creatine was significantly higher as compared with control subjects (1.98 ± 0.49 versus 1.52 ± 0.19 µmol/g Hb, P = 0.007). Peak transvalvular pressure gradient ranged from 46 to 142 mmHg and peak flow velocity ranged from 3.40 to 5.95 m/second. Patients with aortic stenosis had a significantly lower erythrocyte count (387 ± 40 versus 436 ± 42 × 10(4) µL, P = 0.002) and hemoglobin (119 ± 11 versus 135 ± 11 g/L, P < 0.001) as compared with control subjects. Erythrocyte creatine had a fair correlation with peak flow velocity (r = 0.55, P = 0.002).In conclusion, intravascular hemolysis due to destruction of erythrocytes was detected in patients with moderate to severe aortic stenosis and the severity of intravascular hemolysis was related to valvular flow velocity of the aortic valve.

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

Bookstein, J.J.; Alazraki, N.P.; Jassy, L.N.

An experiment was designed to determine whether or not acute pneumococcal pneumonia in dogs is associated with intravascular thrombosis, or with angiographic features distinguishable from pulmonary embolism. In dogs with normal baseline chest radiographs and perfusion scans, pneumonia was produced by transbronchial instillation of type III pneumococcus. After 2 days, perfusion scans demonstrated discrete appropriate defects. In vivo magnification pulmonary arteriography, postmortem pulmonary arteriography, and histologic examination disclosed no evidence of thrombi.

Bullous pyoderma gangrenosum complicated by disseminated intravascular coagulation with subsequent myelodysplastic syndrome (chronic myelomonocytic leukemia).

PubMed

Rogalski, Christina; Paasch, Uwe; Glander, Hans-Jürgen; Haustein, Uwe-Frithjof

2003-01-01

A 33-year-old woman developed a bullous PG precursing a chronic myelomonocytic leukemia (CMML) complicated by life-threatening, disseminated, intravascular coagulation after administration of systemic corticosteroids in combination with immunosuppressant and antibiotic agents. Although the association between PG and leukemia, as well as the coincidence of disseminated intravascular coagulation (DIC) and leukemia, is well known, a premonitoring effect of PG in combination with DIC preceding the diagnosis of chronic myelomonocytic leukemia in the same patient has not been reported recently.

Intravascular ultrasound evaluation of a pseudolesion created by stent placement in the right artery.

PubMed

Zientek, D M; Rodgers, G P

1999-10-01

The creation of a pseudolesion after guidewire placement in tortuous arterial segments is a well recognized phenomenon. Intravascular ultrasound has been useful in assessing deployment of intracoronary stents and equivocal angiographic findings. We present a case in which a pseudolesion was not observed until after placement of an intracoronary stent. Intravascular ultrasound demonstrated no dissection or significant lesion; however, there was focal calcification just distal to the stent providing a substrate for the distorted vessel architecture. The lesion resolved with removal of the guidewire.

In Vitro Capture of Small Ferrous Particles with a Magnetic Filtration Device Designed for Intravascular Use with Intraarterial Chemotherapy: Proof-of-Concept Study.

PubMed

Mabray, Marc C; Lillaney, Prasheel; Sze, Chia-Hung; Losey, Aaron D; Yang, Jeffrey; Kondapavulur, Sravani; Liu, Derek; Saeed, Maythem; Patel, Anand; Cooke, Daniel; Jun, Young-Wook; El-Sayed, Ivan; Wilson, Mark; Hetts, Steven W

2016-03-01

To establish that a magnetic device designed for intravascular use can bind small iron particles in physiologic flow models. Uncoated iron oxide particles 50-100 nm and 1-5 µm in size were tested in a water flow chamber over a period of 10 minutes without a magnet (ie, control) and with large and small prototype magnets. These same particles and 1-µm carboxylic acid-coated iron oxide beads were likewise tested in a serum flow chamber model without a magnet (ie, control) and with the small prototype magnet. Particles were successfully captured from solution. Particle concentrations in solution decreased in all experiments (P < .05 vs matched control runs). At 10 minutes, concentrations were 98% (50-100-nm particles in water with a large magnet), 97% (50-100-nm particles in water with a small magnet), 99% (1-5-µm particles in water with a large magnet), 99% (1-5-µm particles in water with a small magnet), 95% (50-100-nm particles in serum with a small magnet), 92% (1-5-µm particles in serum with a small magnet), and 75% (1-µm coated beads in serum with a small magnet) lower compared with matched control runs. This study demonstrates the concept of magnetic capture of small iron oxide particles in physiologic flow models by using a small wire-mounted magnetic filter designed for intravascular use. Copyright © 2016 SIR. Published by Elsevier Inc. All rights reserved.

Postinfusion Phlebitis: Incidence and Risk Factors

PubMed Central

Webster, Joan; McGrail, Matthew; Marsh, Nicole; Wallis, Marianne C.; Ray-Barruel, Gillian; Rickard, Claire M.

2015-01-01

Objective. To document the incidence of postinfusion phlebitis and to investigate associated risk factors. Design. Analysis of existing data set from a large randomized controlled trial, the primary purpose of which was to compare routine peripheral intravascular catheter changes with changing catheters only on clinical indication. Participants and Setting. Patients admitted to a large, acute general hospital in Queensland, Australia, and who required a peripheral intravenous catheter. Results. 5,907 PIVCs from 3,283 patients were studied. Postinfusion phlebitis at 48 hours was diagnosed in 59 (1.8%) patients. Fifteen (25.4%) of these patients had phlebitis at removal and also at 48 hours after removal. When data were analyzed per catheter, the rate was lower, 62/5907 (1.1%). The only variable associated with postinfusion phlebitis was placement of the catheter in the emergency room (P = 0.03). Conclusion. Although not a common occurrence, postinfusion phlebitis may be problematic so it is important for health care staff to provide patients with information about what to look for after an intravascular device has been removed. This trial is registered with ACTRN12608000445370. PMID:26075092

Factors influencing nurses' decision-making process on leaving in the peripheral intravascular catheter after 96 hours: a longitudinal study.

PubMed

Palese, Alvisa; Cassone, Andrea; Kulla, Annamaria; Dorigo, Sabrina; Magee, Jesse; Artico, Marco; Camero, Francesco; Cassin, Catia; Cialdella, Sandra; Floridia, Giuseppe; Nadlišek, Boris; Palcic, Annamaria; Valle, Giulia; Sclauzero, Paola

2011-01-01

The clinical and research debate on the peripheral intravascular (PIV) catheter length of stay in situ is ongoing. The principal aim of this study was to explore the factors behind a nurse's decision to leave a PIV in place for more than 96 hours. The study focused on 7 northern Italian hospitals in 2009. A consequent sample of 269 PIV catheters was included. Direct observation and interviews were adopted. The time of the expected PIV replacement was fixed at 96 hours after its positioning, in accordance with the international guideline. Several factors were taken into account in regard to replacement of the PIV catheters by nurses, ranging from analysis based on their own clinical experience with PIV complications and analysis of the patient's clinical situation to the critical analysis of their own work situation. This clinical decision-making process is valuable: leaving the PIV in place for more than 96 hours is a complex decision and not simply a guideline violation.

The fibrinogen/CRP ratio as a new parameter for the diagnosis of disseminated intravascular coagulation in patients with HELLP syndrome and as a predictive factor for neonatal outcome.

PubMed

Windsperger, Karin; Lehner, Rainer

2013-02-01

The aim of this study was to determine if the fibrinogen/C-reactive protein (CRP) ratio could be used in obstetrics as a predictor for a disseminated intravascular coagulation. One hundred eleven patients with hemolysis, elevated liver enzymes, and low platelet count syndrome at the Department of Obstetrics and Fetomaternal Medicine (General Hospital, Vienna, Austria) were selected and divided into 2 groups (overt disseminated intravascular coagulation, no overt disseminated intravascular coagulation). The classical parameters and the fibrinogen/CRP ratio were compared. The analysis was carried out using IBM SPSS statistical package (SPSS, Inc, Cary, NC). The fibrinogen/CRP ratio showed significant differences. The receiver-operating characteristic analysis showed for the ratio (area under the curve, 0.74) significantly better discriminative power than for fibrinogen (area under curve, 0.59). The odds ratio for the fibrinogen/CRP ratio was 7.04. Finally, significant correlations between the ratio and the neonatal outcome were found. We suggest the implementation of the fibrinogen/CRP ratio within patients with hemolysis, elevated liver enzymes, and low platelet count syndrome as a diagnostic and prognostic factor for the occurrence of disseminated intravascular coagulation. Copyright © 2013 Mosby, Inc. All rights reserved.

Radiofrequency-enhanced vascular gene transduction and expression for intravascular MR imaging-guided therapy: feasibility study in pigs.

PubMed

Du, Xiangying; Qiu, Bensheng; Zhan, Xiangcan; Kolmakova, Antonina; Gao, Fabao; Hofmann, Lawrence V; Cheng, Linzhao; Chatterjee, Subroto; Yang, Xiaoming

2005-09-01

To evaluate the feasibility of radiofrequency (RF)-enhanced vascular gene transduction and expression by using a magnetic resonance (MR) imaging-heating guidewire as an intravascular heating vehicle during MR imaging-guided therapy. The institutional committee for animal care and use approved the experimental protocol. The study included in vitro evaluation of the use of RF energy to enhance gene transduction and expression in vascular cells, as well as in vivo validation of the feasibility of intravascular MR imaging-guided RF-enhanced vascular gene transduction and expression in pig arteries. For in vitro experiments, approximately 10(4) vascular smooth muscle cells were seeded in each of four chambers of a cell culture plate. Next, 1 mL of a green fluorescent protein gene (gfp)-bearing lentivirus was added to each chamber. Chamber 4 was heated at approximately 41 degrees C for 15 minutes by using an MR imaging-heating guidewire connected to a custom RF generator. At day 6 after transduction, the four chambers were examined and compared at confocal microscopy to determine the efficiency of gfp transduction and expression. For the in vivo experiments, a lentivirus vector bearing a therapeutic gene, vascular endothelial growth factor 165 (VEGF-165), was transferred by using a gene delivery balloon catheter in 18 femoral-iliac arteries (nine artery pairs) in domestic pigs and Yucatan pigs with atherosclerosis. During gene infusion, one femoral-iliac artery in each pig was heated to approximately 41 degrees C with RF energy transferred via the intravascular MR imaging-heating guidewire, while the contralateral artery was not heated (control condition). At day 6, the 18 arteries were harvested for quantitative Western blot analysis to compare VEGF-165 transduction and expression efficiency between RF-heated and nonheated arterial groups. Confocal microscopy showed gfp expression in chamber 4 that was 293% the level of expression in chamber 1 (49.6% +/- 25.8 vs 16.8% +/- 8.0). Results of Western blot analysis showed VEGF-165 expression for normal arteries in the RF-heated group that was 300% the level of expression in the nonheated group (70.4 arbitrary units [au] +/- 107.1 vs 23.5 au +/- 29.8), and, for atherosclerotic arteries in the RF-heated group, 986% the level in the nonheated group (129.2 au +/- 100.3 vs 13.1 au +/- 4.9). Simultaneous monitoring and enhancement of vascular gene delivery and expression is feasible with the MR imaging-heating guidewire.

Intravascular papillary endothelial hyperplasia of the foot.

PubMed

Cisco, R W; McCormac, R M

1994-01-01

Intravascular papillary endothelial hyperplasia is a rare benign reactive lesion usually found in thrombosed subcutaneous blood vessels. The lesion resembles malignant angiosarcoma clinically and histopathologically, and must be diagnosed correctly to avoid inappropriate treatment. The following is a case presentation involving the foot.

Effects of Aged Stored Autologous Red Blood Cells on Human Endothelial Function

PubMed Central

Kanias, Tamir; Triulzi, Darrel; Donadee, Chenell; Barge, Suchitra; Badlam, Jessica; Jain, Shilpa; Belanger, Andrea M.; Kim-Shapiro, Daniel B.

2015-01-01

Rationale: A major abnormality that characterizes the red cell “storage lesion” is increased hemolysis and reduced red cell lifespan after infusion. Low levels of intravascular hemolysis after transfusion of aged stored red cells disrupt nitric oxide (NO) bioavailabity, via accelerated NO scavenging reaction with cell-free plasma hemoglobin. The degree of intravascular hemolysis post-transfusion and effects on endothelial-dependent vasodilation responses to acetylcholine have not been fully characterized in humans. Objectives: To evaluate the effects of blood aged to the limits of Food and Drug Administration–approved storage time on the human microcirculation and endothelial function. Methods: Eighteen healthy individuals donated 1 U of leukopheresed red cells, divided and autologously transfused into the forearm brachial artery 5 and 42 days after blood donation. Blood samples were obtained from stored blood bag supernatants and the antecubital vein of the infusion arm. Forearm blood flow measurements were performed using strain-gauge plethysmography during transfusion, followed by testing of endothelium-dependent blood flow with increasing doses of intraarterial acetylcholine. Measurements and Main Results: We demonstrate that aged stored blood has higher levels of arginase-1 and cell-free plasma hemoglobin. Compared with 5-day blood, the transfusion of 42-day packed red cells decreases acetylcholine-dependent forearm blood flows. Intravascular venous levels of arginase-1 and cell-free plasma hemoglobin increase immediately after red cell transfusion, with more significant increases observed after infusion of 42-day-old blood. Conclusions: We demonstrate that the transfusion of blood at the limits of Food and Drug Administration–approved storage has a significant effect on the forearm circulation and impairs endothelial function. Clinical trial registered with www.clinicaltrials.gov (NCT 01137656) PMID:26222884

76 FR 77834 - Scientific Information Request on Intravascular Diagnostic and Imaging Medical Devices

Federal Register 2010, 2011, 2012, 2013, 2014

2011-12-14

... solicited to inform our Comparative Effectiveness Review of Intravascular Diagnostic Procedures and Imaging... scientific information on this device will improve the quality of this comparative effectiveness review. AHRQ is requesting this scientific information and conducting this comparative effectiveness review...

21 CFR 880.5200 - Intravascular catheter.

Code of Federal Regulations, 2011 CFR

2011-04-01

... 21 Food and Drugs 8 2011-04-01 2011-04-01 false Intravascular catheter. 880.5200 Section 880.5200 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES GENERAL HOSPITAL AND PERSONAL USE DEVICES General Hospital and Personal Use Therapeutic...

21 CFR 880.5200 - Intravascular catheter.

Code of Federal Regulations, 2012 CFR

2012-04-01

... 21 Food and Drugs 8 2012-04-01 2012-04-01 false Intravascular catheter. 880.5200 Section 880.5200 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES GENERAL HOSPITAL AND PERSONAL USE DEVICES General Hospital and Personal Use Therapeutic...

21 CFR 880.5200 - Intravascular catheter.

Code of Federal Regulations, 2014 CFR

2014-04-01

... 21 Food and Drugs 8 2014-04-01 2014-04-01 false Intravascular catheter. 880.5200 Section 880.5200 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES GENERAL HOSPITAL AND PERSONAL USE DEVICES General Hospital and Personal Use Therapeutic...

21 CFR 880.5200 - Intravascular catheter.

Code of Federal Regulations, 2013 CFR

2013-04-01

... 21 Food and Drugs 8 2013-04-01 2013-04-01 false Intravascular catheter. 880.5200 Section 880.5200 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES GENERAL HOSPITAL AND PERSONAL USE DEVICES General Hospital and Personal Use Therapeutic...

Assessment and Management of Volume Overload and Congestion in Chronic Heart Failure: Can Measuring Blood Volume Provide New Insights?

PubMed

Miller, Wayne L

2017-01-01

Volume overload and fluid congestion remain primary clinical challenges in the assessment and management of patients with chronic heart failure (HF). The pathophysiology of volume regulation is complex, and the simple concept of passive intravascular fluid accumulation is not adequate. The dynamics of interstitial and intravascular fluid compartment interactions and fluid redistribution from venous splanchnic beds to the central pulmonary circulation need to be taken into account in strategies of volume management. Clinical bedside evaluations and right heart hemodynamic assessments can alert of changes in volume status, but only the quantitative measurement of total blood volume can help identify the heterogeneity in plasma volume and red blood cell mass that are features of volume overload in chronic HF. The quantitative assessment of intravascular volume is an effective tool to help guide individualized, appropriate therapy. Not all volume overload is the same, and the measurement of intravascular volume identifies heterogeneity to guide tailored therapy.

In Vitro Capture of Small Ferrous Particles with a Magnetic Filtration Device Designed for Intravascular Use with Intraarterial Chemotherapy: Proof-of-Concept Study

PubMed Central

Mabray, Marc C.; Lillaney, Prasheel; Sze, Chia-Hung; Losey, Aaron D.; Yang, Jeffrey; Kondapavulur, Sravani; Liu, Derek; Saeed, Maythem; Patel, Anand; Cooke, Daniel; Jun, Young-Wook; El-Sayed, Ivan; Wilson, Mark; Hetts, Steven W.

2015-01-01

Purpose To establish that a magnetic device designed for intravascular use can bind small iron particles in physiologic flow models. Materials and Methods Uncoated iron oxide particles 50–100 nm and 1–5 μm in size were tested in a water flow chamber over a period of 10 minutes without a magnet (ie, control) and with large and small prototype magnets. These same particles and 1-μm carboxylic acid–coated iron oxide beads were likewise tested in a serum flow chamber model without a magnet (ie, control) and with the small prototype magnet. Results Particles were successfully captured from solution. Particle concentrations in solution decreased in all experiments (P < .05 vs matched control runs). At 10 minutes, concentrations were 98% (50–100-nm particles in water with a large magnet), 97% (50–100-nm particles in water with a small magnet), 99% (1–5-μm particles in water with a large magnet), 99% (1–5-μm particles in water with a small magnet), 95% (50–100-nm particles in serum with a small magnet), 92% (1–5-μm particles in serum with a small magnet), and 75% (1-μm coated beads in serum with a small magnet) lower compared with matched control runs. Conclusions This study demonstrates the concept of magnetic capture of small iron oxide particles in physiologic flow models by using a small wire-mounted magnetic filter designed for intravascular use. PMID:26706187

Fully integrated optical coherence tomography, ultrasound, and indocyanine green based fluorescence tri-modality system for intravascular imaging (Conference Presentation)

NASA Astrophysics Data System (ADS)

Li, Yan; Jing, Joseph C.; Qu, Yueqiao; Miao, Yusi; Ma, Teng; Yu, Mingyue; Zhou, Qifa; Chen, Zhongping

2017-02-01

The rupture of atherosclerotic plaques is the leading cause of acute coronary events, so accurate assessment of plaque is critical. A large lipid pool, thin fibrous cap, and inflammatory reaction are the crucial characteristics for identifying vulnerable plaques. In our study, a tri-modality imaging system for intravascular imaging was designed and implemented. The tri-modality imaging system with a 1-mm probe diameter is able to simultaneously acquire optical coherence tomography (OCT), intravascular ultrasound (IVUS), and fluorescence imaging. Moreover, for fluorescence imaging, we used the FDA-approved indocyanine green (ICG) dye as the contrast agent to target lipid-loaded macrophages. Firstly, IVUS is used as the first step for identifying plaque since IVUS enables the visualization of the layered structures of the artery wall. Due to low soft-tissue contrast, IVUS only provides initial identification of the lipid plaque. Then OCT is used for differentiating fibrosis and lipid pool based on its relatively higher soft tissue contrast and high sensitivity/specificity. Last, fluorescence imaging is used for identifying inflammatory reaction to further confirm whether the plaque is vulnerable or not. Ex vivo experiment of a male New Zealand white rabbit aorta was performed to validate the performance of our tri-modality system. H and E histology results of the rabbit aorta were also presented to check assessment accuracy. The miniature tri-modality probe, together with the use of ICG dye suggest that the system is of great potential for providing a more accurate assessment of vulnerable plaques in clinical applications.

Robust intravascular optical coherence elastography driven by acoustic radiation pressure

NASA Astrophysics Data System (ADS)

van Soest, Gijs; Bouchard, Richard R.; Mastik, Frits; de Jong, Nico; van der Steen, Anton F. W.

2007-07-01

High strain spots in the vessel wall indicate the presence of vulnerable plaques. The majority of acute cardiovascular events are preceded by rupture of such a plaque in a coronary artery. Intracoronary optical coherence tomography (OCT) can be extended, in principle, to an elastography technique, mapping the strain in the vascular wall. However, the susceptibility of OCT to frame-to-frame decorrelation, caused by tissue and catheter motion, inhibits reliable tissue displacement tracking and has to date obstructed the development of OCT-based intravascular elastography. We introduce a new technique for intravascular optical coherence elastography, which is robust against motion artifacts. Using acoustic radiation force, we apply a pressure to deform the tissue synchronously with the line scan rate of the OCT instrument. Radial tissue displacement can be tracked based on the correlation between adjacent lines, instead of subsequent frames in conventional elastography. The viability of the method is demonstrated with a simulation study. The root mean square (rms) error of the displacement estimate is 0.55 μm, and the rms error of the strain is 0.6%. It is shown that high-strain spots in the vessel wall, such as observed at the sites of vulnerable atherosclerotic lesions, can be detected with the technique. Experiments to realize this new elastographic method are presented. Simultaneous optical and ultrasonic pulse-echo tracking demonstrate that the material can be put in a high-frequency oscillatory motion with an amplitude of several micrometers, more than sufficient for accurate tracking with OCT. The resulting data are used to optimize the acoustic pushing sequence and geometry.

Temporary prophylactic intravascular balloon occlusion of the common iliac arteries before cesarean hysterectomy for controlling operative blood loss in abnormal placentation.

PubMed

Chou, Min Min; Kung, Hsiao Fan; Hwang, Jen I; Chen, Wei Chi; Tseng, Jenn Jhy

2015-10-01

The purpose of this study was to investigate the efficacy and safety of temporary prophylactic intravascular balloon occlusion of the common iliac arteries (CIA) before planned cesarean hysterectomy for controlling operative blood loss in abnormal placentation. A retrospective study of 13 pregnant women at risk for placenta accreta identified using sequential obstetric ultrasonography and magnetic resonance imaging from January 2007 to December 2009 was performed. Temporary prophylactic intravascular balloon catheterization of the bilateral CIA before cesarean hysterectomy was performed by interventional radiologists. The maximum duration of occlusion time of CIA must not exceed 60 minutes. The primary outcome for this study included estimated blood loss and secondary outcomes included the development of thromboembolism, disseminated intravascular coagulation and surgical complications. Among these 13 patients, the mean age of the patients was 32.8 ± 0.7 years (range 29-37 years). The mean gestational age at cesarean hysterectomy was 32.2 ± 0.9 weeks (range 28-36 weeks), and the mean intraoperative blood loss was 1902.3 ± 578.8 mL (range 500-8000 mL). Operative bleeding was controlled by conservative treatment without additional surgery in two cases. Importantly, two patients (15.8%) had severe complications possibly related to the interventional procedure. One patient was noted to have a popliteal artery thrombosis. A second patient had an external iliac artery thrombosis with 80-90% occlusion. Both patients required antithrombotic treatment without sequelae. With limited experience in this small series, we observed a statistically significant reduction in operative blood loss after the use of temporary prophylactic balloon occlusion of the CIA technique compared with historical controls of similar demographic characteristics previously published (1902.3 ± 578.8 mL, range 500-8000 mL vs. 4445.7 ± 996.48 mL, range 1040-15,000 mL, p = 0.0402). Additionally, two patients had arterial thrombosis. These preliminary findings are based on a small number of patients, and therefore further investigation is needed to determine the effectiveness and safety of this new technique. Copyright © 2015. Published by Elsevier B.V.

Quinine-induced disseminated intravascular coagulation.

PubMed

Spearing, R L; Hickton, C M; Sizeland, P; Hannah, A; Bailey, R R

Recurrent disseminated intravascular coagulation occurred in 3 women after ingestion of quinine tablets for cramp. All had circulating quinine-dependent antibodies to platelets and in 2 there was initial evidence of antibody consumption, with low titres that rose steeply over the next few days and remained high for many months.

21 CFR 880.5440 - Intravascular administration set.

Code of Federal Regulations, 2010 CFR

2010-04-01

... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Intravascular administration set. 880.5440 Section 880.5440 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES... Compounding Systems; Final Guidance for Industry and FDA Reviewers.” Pharmacy compounding systems classified...

Hybrid intravascular imaging: recent advances, technical considerations, and current applications in the study of plaque pathophysiology.

PubMed

Bourantas, Christos V; Jaffer, Farouc A; Gijsen, Frank J; van Soest, Gijs; Madden, Sean P; Courtney, Brian K; Fard, Ali M; Tenekecioglu, Erhan; Zeng, Yaping; van der Steen, Antonius F W; Emelianov, Stanislav; Muller, James; Stone, Peter H; Marcu, Laura; Tearney, Guillermo J; Serruys, Patrick W

2017-02-07

Cumulative evidence from histology-based studies demonstrate that the currently available intravascular imaging techniques have fundamental limitations that do not allow complete and detailed evaluation of plaque morphology and pathobiology, limiting the ability to accurately identify high-risk plaques. To overcome these drawbacks, new efforts are developing for data fusion methodologies and the design of hybrid, dual-probe catheters to enable accurate assessment of plaque characteristics, and reliable identification of high-risk lesions. Today several dual-probe catheters have been introduced including combined near infrared spectroscopy-intravascular ultrasound (NIRS-IVUS), that is already commercially available, IVUS-optical coherence tomography (OCT), the OCT-NIRS, the OCT-near infrared fluorescence (NIRF) molecular imaging, IVUS-NIRF, IVUS intravascular photoacoustic imaging and combined fluorescence lifetime-IVUS imaging. These multimodal approaches appear able to overcome limitations of standalone imaging and provide comprehensive visualization of plaque composition and plaque biology. The aim of this review article is to summarize the advances in hybrid intravascular imaging, discuss the technical challenges that should be addressed in order to have a use in the clinical arena, and present the evidence from their first applications aiming to highlight their potential value in the study of atherosclerosis. Published on behalf of the European Society of Cardiology. All rights reserved. © The Author 2016. For permissions please email: journals.permissions@oup.com.

Relation between lung perfusion defects and intravascular clots in acute pulmonary thromboembolism: assessment with breath-hold SPECT-CT pulmonary angiography fusion images.

PubMed

Suga, Kazuyoshi; Yasuhiko, Kawakami; Iwanaga, Hideyuki; Tokuda, Osamu; Matsunaga, Naofumi

2008-09-01

The relation between lung perfusion defects and intravascular clots in acute pulmonary thromboembolism (PTE) was comprehensively assessed on deep-inspiratory breath-hold (DIBrH) perfusion SPECT-computed tomographic pulmonary angiography (CTPA) fusion images. Subjects were 34 acute PTE patients, who had successfully performed DIBrH perfusion SPECT using a dual-headed SPECT and a respiratory tracking system. Automated DIBrH SPECT-CTPA fusion images were used to assess the relation between lung perfusion defects and intravascular clots detected by CTPA. DIBrH SPECT visualized 175 lobar/segmental or subsegmental defects in 34 patients, and CTPA visualized 61 intravascular clots at variable locations in 30 (88%) patients, but no clots in four (12%) patients. In 30 patients with clots, the fusion images confirmed that 69 (41%) perfusion defects (20 segmental, 45 subsegmental and 4 lobar defects) of total 166 defects were located in lung territories without clots, although the remaining 97 (58%) defects were located in lung territories with clots. Perfusion defect was absent in lung territories with clots (one lobar branch and three segmental branches) in four (12%) of these patients. In four patients without clots, nine perfusion defects including four segmental ones were present. Because of unexpected dissociation between intravascular clots and lung perfusion defects, the present fusion images will be a useful adjunct to CTPA in the diagnosis of acute PTE.

Low-level He-Ne laser in intravascular irradiation treatment of schizophrenia

NASA Astrophysics Data System (ADS)

Zhou, Yu-Xue; Fu, Zheng-Hua

1998-11-01

Intravascular low level He-Ne laser irradiation is a new therapy developed in recent years. In our hospital it was applied in the treatment and observation of 220 cases of schizophrenia, among which certain effect was achieved and about which the detail was collated and elaborated.

21 CFR 880.5970 - Percutaneous, implanted, long-term intravascular catheter.

Code of Federal Regulations, 2012 CFR

2012-04-01

... 21 Food and Drugs 8 2012-04-01 2012-04-01 false Percutaneous, implanted, long-term intravascular catheter. 880.5970 Section 880.5970 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES GENERAL HOSPITAL AND PERSONAL USE DEVICES General Hospital...

21 CFR 880.5970 - Percutaneous, implanted, long-term intravascular catheter.

Code of Federal Regulations, 2011 CFR

2011-04-01

... 21 Food and Drugs 8 2011-04-01 2011-04-01 false Percutaneous, implanted, long-term intravascular catheter. 880.5970 Section 880.5970 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES GENERAL HOSPITAL AND PERSONAL USE DEVICES General Hospital...

21 CFR 880.5970 - Percutaneous, implanted, long-term intravascular catheter.

Code of Federal Regulations, 2013 CFR

2013-04-01

... 21 Food and Drugs 8 2013-04-01 2013-04-01 false Percutaneous, implanted, long-term intravascular catheter. 880.5970 Section 880.5970 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES GENERAL HOSPITAL AND PERSONAL USE DEVICES General Hospital...

21 CFR 880.5970 - Percutaneous, implanted, long-term intravascular catheter.

Code of Federal Regulations, 2010 CFR

2010-04-01

... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Percutaneous, implanted, long-term intravascular catheter. 880.5970 Section 880.5970 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES GENERAL HOSPITAL AND PERSONAL USE DEVICES General Hospital...

21 CFR 880.5970 - Percutaneous, implanted, long-term intravascular catheter.

Code of Federal Regulations, 2014 CFR

2014-04-01

... 21 Food and Drugs 8 2014-04-01 2014-04-01 false Percutaneous, implanted, long-term intravascular catheter. 880.5970 Section 880.5970 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES GENERAL HOSPITAL AND PERSONAL USE DEVICES General Hospital...

Efficacy and complications associated with a modified inferior alveolar nerve block technique. A randomized, triple-blind clinical trial

PubMed Central

Montserrat-Bosch, Marta; Nogueira-Magalhães, Pedro; Arnabat-Dominguez, Josep; Valmaseda-Castellón, Eduard; Gay-Escoda, Cosme

2014-01-01

Objectives: To compare the efficacy and complication rates of two different techniques for inferior alveolar nerve blocks (IANB). Study Design: A randomized, triple-blind clinical trial comprising 109 patients who required lower third molar removal was performed. In the control group, all patients received an IANB using the conventional Halsted technique, whereas in the experimental group, a modified technique using a more inferior injection point was performed. Results: A total of 100 patients were randomized. The modified technique group showed a significantly higher onset time in the lower lip and chin area, and was frequently associated to a lingual electric discharge sensation. Three failures were recorded, 2 of them in the experimental group. No relevant local or systemic complications were registered. Conclusions: Both IANB techniques used in this trial are suitable for lower third molar removal. However, performing an inferior alveolar nerve block in a more inferior position (modified technique) extends the onset time, does not seem to reduce the risk of intravascular injections and might increase the risk of lingual nerve injuries. Key words:Dental anesthesia, inferior alveolar nerve block, lidocaine, third molar, intravascular injection. PMID:24608204

In vitro three-dimensional aortic vasculature modeling based on sensor fusion between intravascular ultrasound and magnetic tracker.

PubMed

Shi, Chaoyang; Tercero, Carlos; Ikeda, Seiichi; Ooe, Katsutoshi; Fukuda, Toshio; Komori, Kimihiro; Yamamoto, Kiyohito

2012-09-01

It is desirable to reduce aortic stent graft installation time and the amount of contrast media used for this process. Guidance with augmented reality can achieve this by facilitating alignment of the stent graft with the renal and mesenteric arteries. For this purpose, a sensor fusion is proposed between intravascular ultrasound (IVUS) and magnetic trackers to construct three-dimensional virtual reality models of the blood vessels, as well as improvements to the gradient vector flow snake for boundary detection in ultrasound images. In vitro vasculature imaging experiments were done with hybrid probe and silicone models of the vasculature. The dispersion of samples for the magnetic tracker in the hybrid probe increased less than 1 mm when the IVUS was activated. Three-dimensional models of the descending thoracic aorta, with cross-section radius average error of 0.94 mm, were built from the data fusion. The development of this technology will enable reduction in the amount of contrast media required for in vivo and real-time three-dimensional blood vessel imaging. Copyright © 2012 John Wiley & Sons, Ltd.

21 CFR 880.5210 - Intravascular catheter securement device.

Code of Federal Regulations, 2010 CFR

2010-04-01

... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Intravascular catheter securement device. 880.5210 Section 880.5210 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES... and is used to keep the hub of the needle or the catheter flat and securely anchored to the skin. (b...

21 CFR 880.5210 - Intravascular catheter securement device.

Code of Federal Regulations, 2011 CFR

2011-04-01

... 21 Food and Drugs 8 2011-04-01 2011-04-01 false Intravascular catheter securement device. 880.5210 Section 880.5210 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES... and is used to keep the hub of the needle or the catheter flat and securely anchored to the skin. (b...

[Pulmonary intravascular talcosis: A case report].

PubMed

Reverso-Meinietti, J; Vandenbos, F; Risso, K; Coyne, J; Leroy, S; Padovani, B; Burel-Vandenbos, F

2018-04-09

Pulmonary intravascular talcosis is a rare condition occurring in intravenous drug users injecting oral medications. Talc results in a foreign-body granulomatous reaction giving a radiological haematogenic miliary appearance mimicking miliary tuberculosis. Drug users represent a population at risk for both these conditions and their distinction may be challenging. We reported the case of a man, 33 year-old, intravenous drug addict, detected by the health services because he was the partner of a person who died of contagious and multi-resistant tuberculosis. Chest X-ray and CT scan showed a typical miliary appearance. Despite negative microbiology, clinical diagnosis of miliary tuberculosis was retained. Due to the lack of radiological improvement despite appropriate antibiotic treatment, re-evaluation and trans-bronchial biopsy were undertaken. The presence of granulomas centered by birefringent foreign bodies in polarized light led to a diagnosis of pulmonary intravascular talcosis. In the presence of pulmonary miliary in an intravenous drug addict, intravascular talcosis should be suspected. Copyright © 2018 Société Nationale Française de Médecine Interne (SNFMI). Published by Elsevier SAS. All rights reserved.

Simultaneous radiofrequency (RF) heating and magnetic resonance (MR) thermal mapping using an intravascular MR imaging/RF heating system.

PubMed

Qiu, Bensheng; El-Sharkawy, Abdel-Monem; Paliwal, Vaishali; Karmarkar, Parag; Gao, Fabao; Atalar, Ergin; Yang, Xiaoming

2005-07-01

Previous studies have confirmed the possibility of using an intravascular MR imaging guidewire (MRIG) as a heating source to enhance vascular gene transfection/expression. This motivated us to develop a new intravascular system that can perform MR imaging, radiofrequncy (RF) heating, and MR temperature monitoring simultaneously in an MR scanner. To validate this concept, a series of mathematical simulations of RF power loss along a 0.032-inch MRIG and RF energy spatial distribution were performed to determine the optimum RF heating frequency. Then, an RF generator/amplifier and a filter box were built. The possibility for simultaneous RF heating and MR thermal mapping of the system was confirmed in vitro using a phantom, and the obtained thermal mapping profile was compared with the simulated RF power distribution. Subsequently, the feasibility of simultaneous RF heating and temperature monitoring was successfully validated in vivo in the aorta of living rabbits. This MR imaging/RF heating system offers a potential tool for intravascular MR-mediated, RF-enhanced vascular gene therapy.

The neuroprotective effects of intravascular low level laser irradiation on cerebral ischemia rats

NASA Astrophysics Data System (ADS)

Qiu, Yongming; Lu, Zhaofeng; Wang, Zhongguang; Jiang, Jiyao

2005-07-01

The effects of intravascular low level laser irradiation of He-Ne on rat MCAo-induced cerebral injury were studied. The results showed that control rats (subjected to MCAo injury without laser treatment) at 7d exhibited striatal and cortical brain infarction in the right hemisphere from approximately 3 to 11mm from the front pole. the total infarct volume in this group was 34.5+/-8.1mm3. For experimental rats (with laser management), the total infarct volume was 29.0+/-9.0mm3. P was gained less than 0.05. The neurological score of control group was 4.7+/-0.6 and it was 5.2+/-1.0 in experimental group, comparison by statistical analysis showed P less than 0.05. The cerebral pathological damages in the control group were more severe than in experimental group. We concluded that the intravascular low level laser irradiation has no remarked complication and is helpful to reduce ischemic damage. There is clinically potential for the application of intravascular He-Ne low level laser irradiation in ischemia stroke.

Neurological Limitations of Aircraft Operations: Human Performance Implications (les Limitations neurologiques des operations aeriennes: les Consequences pour les performances des equipages).

DTIC Science & Technology

1996-04-01

Amniotic fluid Debris?* Young women Long bone fracture Fat * Any age Chronic intravenous drug users Talc* Any age Disseminated intravascular coagulapathy...maximal stress at which bone fracture occurs. This study demonstrated the usefulness of finite Results from centrifuge experiments element analysis for...Vine Street M/S 455 Philadelphia, PA 19102-1192, USA SUMMARY Exposure to Impact Acceleration (15). In these reports, fracture of the bones, dislocation

Intravascular US-Guided Portal Vein Access: Improved Procedural Metrics during TIPS Creation.

PubMed

Gipson, Matthew G; Smith, Mitchell T; Durham, Janette D; Brown, Anthony; Johnson, Thor; Ray, Charles E; Gupta, Rajan K; Kondo, Kimi L; Rochon, Paul J; Ryu, Robert K

2016-08-01

To evaluate transjugular intrahepatic portosystemic shunt (TIPS) outcomes and procedure metrics with the use of three different image guidance techniques for portal vein (PV) access during TIPS creation. A retrospective review of consecutive patients who underwent TIPS procedures for a range of indications during a 28-month study period identified a population of 68 patients. This was stratified by PV access techniques: fluoroscopic guidance with or without portography (n = 26), PV marker wire guidance (n = 18), or intravascular ultrasound (US) guidance (n = 24). Procedural outcomes and procedural metrics, including radiation exposure, contrast agent volume used, procedure duration, and PV access time, were analyzed. No differences in demographic or procedural characteristics were found among the three groups. Technical success, technical success of the primary planned approach, hemodynamic success, portosystemic gradient, and procedure-related complications were not significantly different among groups. Fluoroscopy time (P = .003), air kerma (P = .01), contrast agent volume (P = .003), and total procedural time (P = .02) were reduced with intravascular US guidance compared with fluoroscopic guidance. Fluoroscopy time (P = .01) and contrast agent volume (P = .02) were reduced with intravascular US guidance compared with marker wire guidance. Intravascular US guidance of PV access during TIPS creation not only facilitates successful TIPS creation in patients with challenging anatomy, as suggested by previous investigations, but also reduces important procedure metrics including radiation exposure, contrast agent volume, and overall procedure duration compared with fluoroscopically guided TIPS creation. Copyright © 2016 SIR. Published by Elsevier Inc. All rights reserved.

Intravascular administration of mannitol for acute kidney injury prevention: a systematic review and meta-analysis.

PubMed

Yang, Bo; Xu, Jing; Xu, Fengying; Zou, Zui; Ye, Chaoyang; Mei, Changlin; Mao, Zhiguo

2014-01-01

The effects of mannitol administration on acute kidney injury (AKI) prevention remain uncertain, as the results from clinical studies were conflicting. Due to the lack of strong evidence, the KDIGO Guideline for AKI did not propose completely evidence-based recommendations on this issue. We searched PubMed, EMBASE, clinicaltrials.gov and Cochrane Controlled Trials Register. Randomized controlled trials on adult patients at increased risk of AKI were considered on the condition that they compared the effects of intravascular administration of mannitol plus expansion of intravascular volume with expansion of intravascular volume alone. We calculated pooled risk ratios, numbers needed to treat and mean differences with 95% confidence intervals for dichotomous data and continuous data, respectively. Nine trials involving 626 patients were identified. Compared with expansion of intravascular volume alone, mannitol infusion for AKI prevention in high-risk patients can not reduce the serum creatinine level (MD 1.63, 95% CI -6.02 to 9.28). Subgroup analyses demonstrated that serum creatinine level is negatively affected by the use of mannitol in patients undergoing an injection of radiocontrast agents (MD 17.90, 95% CI 8.56 to 27.24). Mannitol administration may reduce the incidence of acute renal failure or the need of dialysis in recipients of renal transplantation (RR 0.34, 95% CI 0.21 to 0.57, NNT 3.03, 95% CI 2.17 to 5.00). But similar effects were not found in patients at high AKI risk, without receiving renal transplantation (RR 0.29, 95% CI 0.01 to 6.60). Intravascular administration of mannitol does not convey additional beneficial effects beyond adequate hydration in the patients at increased risk of AKI. For contrast-induced nephropathy, the use of mannitol is even detrimental. Further research evaluating the efficiency of mannitol infusions in the recipients of renal allograft should be undertaken.

Intravascular Administration of Mannitol for Acute Kidney Injury Prevention: A Systematic Review and Meta-Analysis

PubMed Central

Xu, Fengying; Zou, Zui; Ye, Chaoyang; Mei, Changlin; Mao, Zhiguo

2014-01-01

Background The effects of mannitol administration on acute kidney injury (AKI) prevention remain uncertain, as the results from clinical studies were conflicting. Due to the lack of strong evidence, the KDIGO Guideline for AKI did not propose completely evidence-based recommendations on this issue. Methods We searched PubMed, EMBASE, clinicaltrials.gov and Cochrane Controlled Trials Register. Randomized controlled trials on adult patients at increased risk of AKI were considered on the condition that they compared the effects of intravascular administration of mannitol plus expansion of intravascular volume with expansion of intravascular volume alone. We calculated pooled risk ratios, numbers needed to treat and mean differences with 95% confidence intervals for dichotomous data and continuous data, respectively. Results Nine trials involving 626 patients were identified. Compared with expansion of intravascular volume alone, mannitol infusion for AKI prevention in high-risk patients can not reduce the serum creatinine level (MD 1.63, 95% CI −6.02 to 9.28). Subgroup analyses demonstrated that serum creatinine level is negatively affected by the use of mannitol in patients undergoing an injection of radiocontrast agents (MD 17.90, 95% CI 8.56 to 27.24). Mannitol administration may reduce the incidence of acute renal failure or the need of dialysis in recipients of renal transplantation (RR 0.34, 95% CI 0.21 to 0.57, NNT 3.03, 95% CI 2.17 to 5.00). But similar effects were not found in patients at high AKI risk, without receiving renal transplantation (RR 0.29, 95% CI 0.01 to 6.60). Conclusions Intravascular administration of mannitol does not convey additional beneficial effects beyond adequate hydration in the patients at increased risk of AKI. For contrast-induced nephropathy, the use of mannitol is even detrimental. Further research evaluating the efficiency of mannitol infusions in the recipients of renal allograft should be undertaken. PMID:24454783

The dynamic of FUS-induced BBB Opening in Mouse Brain assessed by contrast enhanced MRI

NASA Astrophysics Data System (ADS)

Jenne, Jürgen W.; Krafft, Axel J.; Maier, Florian; Krause, Marie N.; Kleber, Susanne; Huber, Peter E.; Martin-Villalba, Ana; Bock, Michael

2010-03-01

Focused ultrasound (FUS) in combination with the administration of gas-filled microbubbles, can induce a localized and reversible opening of the blood brain barrier (BBB). Contrast enhanced magnetic resonance imaging (MRI) has been demonstrated as a precise tool to monitor such a local BBB disruption. However, the opening/closing mechanisms of the BBB with FUS are still largely unknown. In this ongoing project, we study the BBB opening dynamics in mouse brain comparing an interstitial and an intravascular MR contrast agent (CA). FUS in mouse brain was performed with an MRI compatible treatment setup (1.7 MHz fix-focus US transducer, f' = 68 mm, NA = 0.44; focus: 8.1 mm length; O/ = 1.1 mm) in a 1.5 T whole body MRI system. For BBB opening, forty 10 ms-long FUS-pulses were applied at a repetition rate of 1 Hz at 1 MPa. The i.v. administration of the micro bubbles (50 μl SonoVue®) was started simultaneously with FUS exposure. To analyze the BBB opening process, short-term and long-term MRI signal dynamics of the interstitial MR contrast agent Magnevist® and the intravascular CA Vasovist® (Bayer-Schering) were studied. To assess short-term signal dynamics, T1-weighted inversion recovery turbo FLASH images (1s) were repeatedly acquired. Repeated 3D FLASH acquisitions (90 s) were used to assess long-term MRI signal dynamics. The short-term MRI signal enhancements showed comparable time constants for both types of MR contrast agents: 1.1 s (interstitial) vs. 0.8 s (intravascular). This time constant may serve as a time constant of the BBB opening process with the given FUS exposure parameters. For the long-term signal dynamics the intravascular CA (62±10 min) showed a fife times greater time constant as the interstitial contrast agent (12±10 min). This might be explained by the high molecular weight (˜60 kDa) of the intravascular Vasovist due to its reversible binding to blood serum albumin resulting in a prolonged half-life in the blood stream compared to the interstitial CA. As the intravascular CA offers a much longer time window for therapy assessment, FUS-BBB therapy control with an intravascular CA might be favorable.

Intravascular versus surface cooling for targeted temperature management after out-of-hospital cardiac arrest - an analysis of the TTM trial data.

PubMed

Glover, Guy W; Thomas, Richard M; Vamvakas, George; Al-Subaie, Nawaf; Cranshaw, Jules; Walden, Andrew; Wise, Matthew P; Ostermann, Marlies; Thomas-Jones, Emma; Cronberg, Tobias; Erlinge, David; Gasche, Yvan; Hassager, Christian; Horn, Janneke; Kjaergaard, Jesper; Kuiper, Michael; Pellis, Tommaso; Stammet, Pascal; Wanscher, Michael; Wetterslev, Jørn; Friberg, Hans; Nielsen, Niklas

2016-11-26

Targeted temperature management is recommended after out-of-hospital cardiac arrest and may be achieved using a variety of cooling devices. This study was conducted to explore the performance and outcomes for intravascular versus surface devices for targeted temperature management after out-of-hospital cardiac arrest. A retrospective analysis of data from the Targeted Temperature Management trial. N = 934. A total of 240 patients (26%) managed with intravascular versus 694 (74%) with surface devices. Devices were assessed for speed and precision during the induction, maintenance and rewarming phases in addition to adverse events. All-cause mortality, as well as a composite of poor neurological function or death, as evaluated by the Cerebral Performance Category and modified Rankin scale were analysed. For patients managed at 33 °C there was no difference between intravascular and surface groups in the median time taken to achieve target temperature (210 [interquartile range (IQR) 180] minutes vs. 240 [IQR 180] minutes, p = 0.58), maximum rate of cooling (1.0 [0.7] vs. 1.0 [0.9] °C/hr, p = 0.44), the number of patients who reached target temperature (within 4 hours (65% vs. 60%, p = 0.30); or ever (100% vs. 97%, p = 0.47), or episodes of overcooling (8% vs. 34%, p = 0.15). In the maintenance phase, cumulative temperature deviation (median 3.2 [IQR 5.0] °C hr vs. 9.3 [IQR 8.0] °C hr, p = <0.001), number of patients ever out of range (57.0% vs. 91.5%, p = 0.006) and median time out of range (1 [IQR 4.0] hours vs. 8.0 [IQR 9.0] hours, p = <0.001) were all significantly greater in the surface group although there was no difference in the occurrence of pyrexia. Adverse events were not different between intravascular and surface groups. There was no statistically significant difference in mortality (intravascular 46.3% vs. surface 50.0%; p = 0.32), Cerebral Performance Category scale 3-5 (49.0% vs. 54.3%; p = 0.18) or modified Rankin scale 4-6 (49.0% vs. 53.0%; p = 0.48). Intravascular and surface cooling was equally effective during induction of mild hypothermia. However, surface cooling was associated with less precision during the maintenance phase. There was no difference in adverse events, mortality or poor neurological outcomes between patients treated with intravascular and surface cooling devices. TTM trial ClinicalTrials.gov number https://clinicaltrials.gov/ct2/show/NCT01020916 NCT01020916; 25 November 2009.

Gordonia bronchialis bacteremia and pleural infection: case report and review of the literature.

PubMed

Johnson, Jennifer A; Onderdonk, Andrew B; Cosimi, Lisa A; Yawetz, Sigal; Lasker, Brent A; Bolcen, Shanna J; Brown, June M; Marty, Francisco M

2011-04-01

Gordonia species are aerobic actinomycetes recently recognized as causing human disease, often in the setting of intravascular catheter-related infections. We describe a case of Gordonia bronchialis bacteremia and pleural space infection in the absence of an indwelling intravascular catheter and review the breadth of reported infections with this emerging pathogen.

Simultaneous fluorometry and phosphorometry of Langendorff perfused rat heart: ex vivo animal studies

NASA Astrophysics Data System (ADS)

Ranji, Mahsa; Jaggard, Dwight L.; Apreleva, Sofia V.; Vinogradov, Sergei A.; Chance, Britton

2006-10-01

Fluorescence imaging of intrinsic fluorophores of tissue is a powerful method to assess metabolic changes at the cellular and intracellular levels. At the same time, exogenous phosphorescent probes can be used to accurately measure intravascular tissue oxygenation. Heart failure is the leading cause of death in America. A rat heart can potentially model the human heart to study failures or other abnormalities optically. We report simultaneous fluorescence and phosphorescence measurements performed on a rat heart. We have used two different optical systems to acquire fluorescence signals of flavoprotein and nicotinamide adenine dinucleotide—the two intrinsic fluorophores of mitochondria—and the phosphorescence signal of an intravascular oxygen probe to extract intracellular and intravascular metabolism loads, respectively.

Metabolism and Distribution of 131 I-labelled Albumin in the Pig *

PubMed Central

Dich, John; Nielsen, Knud

1963-01-01

The biological behaviour of porcine 131I-albumin has been investigated in 11 normal pigs, weight appr. 20 kg. Mean values obtained from the experiments are: Albumin degradation: 15.1 ± 2.1 per cent/day (0.18 ± 0.01 g/kg/day), extravascular: intravascular albumin ratio: 1.71 ± 0.29. Fecal excretion of radio-activity ranged from 0.77—1.87 per cent of the dose (mean: 1.11 per cent) during the first 4 days of the experiment. The results are discussed with special reference to the rôle of the gastrointestinal tract in health and in various digestive disorders. PMID:17649473

Inhibition of Acid-induced Lung Injury by Hyperosmolar Sucrose in Rats

PubMed Central

Safdar, Zeenat; Yiming, Maimiti; Grunig, Gabriele; Bhattacharya, Jahar

2005-01-01

Rationale: Acid aspiration causes acute lung injury (ALI). Recently, we showed that a brief intravascular infusion of hyperosmolar sucrose, given concurrently with airway acid instillation, effectively blocks the ensuing ALI. Objectives: The objective of the present study was to determine the extent to which intravascular infusion of hyperosmolar sucrose might protect against acid-induced ALI when given either before or after acid instillation. Methods: Our studies were conducted in anesthetized rats and in isolated, blood-perfused rat lungs. We instilled HCl through the airway, and we quantified lung injury in terms of the extravascular lung water (EVLW) content, filtration coefficient (Kfc), and cell counts and protein concentration in the bronchoalveolar lavage. We infused hyperosmolar sucrose via the femoral vein. Results: In anesthetized rats, airway HCl instillation induced ALI as indicated by a 52% increase of EVLW and a threefold increase in Kfc. However, a 15-min intravenous infusion of hyperosmolar sucrose given up to 1 h before or 30 min after acid instillation markedly blunted the increases in EVLW, as well as the increases in cell count, and in protein concentration in the bronchoalveolar lavage. Hyperosmolar pretreatment also blocked the acid-induced increase of Kfc. Studies in isolated perfused lungs indicated that the protective effect of hyperosmolar sucrose was leukocyte independent. Conclusions: We conclude that a brief period of vascular hyperosmolarity protects against acid-induced ALI when the infusion is administered shortly before, or shortly after, acid instillation in the airway. The potential applicability of hyperosmolar sucrose in therapy for ALI requires consideration. PMID:16109982

[EXPERIMENTAL MODEL AND CURRENCY OF EXPERIMENT OF DISTANT RESULTS OF LEAD EXPOSITION].

PubMed

Pataraia, G; Bagashvili, T; Andronikashvili, G; Gurashvili, T; Gogeshvili, K; Avalishvili, M

2017-02-01

In order to explore the distant results of exposition of little doses of lead, for the objective of the experiment model we have selected 32 mongral rats, of different age, but aged of both sex. Experimental animals were divided in two groups. During first two month from the beginning of the experiment, together with permissible food, animals were given the water, in which was open Pb(NO3)2 - to first group 1.5 mg on kg/weight and to II group 15 mg on kg/weight during the day and night. Before the beginning of the experiment, in the time of process and after it, observation was conducted, description and collection of photo-video materials about the behavior of animals, physiological parameters, possible change of weight, clear-sighted changes in appearance. During the autopsy of the animal, died during the experiment, it turned out that the reason of the death was acute heart failure caused by septicopyemia, the bilateral abscess pneumonia and right sided purulent pleurisy. The reason of the death of second animal was DIC (disseminated intravascular coagulation) Syndrome and the polyorganic pathology caused by it. We made the Nembutal injection to third animal because there was detected the 50×40×20 sized subcutaneous formation on the right surface of the chest, that turned out to be the breast adenoma with cystic fibrosis. After the completion of the experiment of distant results of lead exposition, surviving rats before autopsy will be dropped to sleep with high dose of drugs in compliance with the "Guidelines of animal care and ethical behavior", taken material will be processed for histopathological (in case of necessity histochemical and imunomorphological) and electronic microscopic researches.

An intravascular lymphoma with extravascular tendencies.

PubMed

Thomas, Cody A; Guileyardo, Joseph M; Krause, John R

2014-10-01

Intravascular large B-cell lymphoma (IVL) is rare and characterized by selective growth of neoplastic cells within the lumina of small blood vessels. We present the case of a 69-year-old woman who died of a widespread IVL with extravascular involvement of the lymph nodes, liver, bladder, and adrenal gland. This report discusses the unique features of IVL with concurrent extravascular components.

Rotational multispectral fluorescence lifetime imaging and intravascular ultrasound: bimodal system for intravascular applications

PubMed Central

Ma, Dinglong; Bec, Julien; Yankelevich, Diego R.; Gorpas, Dimitris; Fatakdawala, Hussain; Marcu, Laura

2014-01-01

Abstract. We report the development and validation of a hybrid intravascular diagnostic system combining multispectral fluorescence lifetime imaging (FLIm) and intravascular ultrasound (IVUS) for cardiovascular imaging applications. A prototype FLIm system based on fluorescence pulse sampling technique providing information on artery biochemical composition was integrated with a commercial IVUS system providing information on artery morphology. A customized 3-Fr bimodal catheter combining a rotational side-view fiberoptic and a 40-MHz IVUS transducer was constructed for sequential helical scanning (rotation and pullback) of tubular structures. Validation of this bimodal approach was conducted in pig heart coronary arteries. Spatial resolution, fluorescence detection efficiency, pulse broadening effect, and lifetime measurement variability of the FLIm system were systematically evaluated. Current results show that this system is capable of temporarily resolving the fluorescence emission simultaneously in multiple spectral channels in a single pullback sequence. Accurate measurements of fluorescence decay characteristics from arterial segments can be obtained rapidly (e.g., 20 mm in 5 s), and accurate co-registration of fluorescence and ultrasound features can be achieved. The current finding demonstrates the compatibility of FLIm instrumentation with in vivo clinical investigations and its potential to complement conventional IVUS during catheterization procedures. PMID:24898604

A novel dual-frequency imaging method for intravascular ultrasound applications.

PubMed

Qiu, Weibao; Chen, Yan; Wong, Chi-Man; Liu, Baoqiang; Dai, Jiyan; Zheng, Hairong

2015-03-01

Intravascular ultrasound (IVUS), which is able to delineate internal structures of vessel wall with fine spatial resolution, has greatly enriched the knowledge of coronary atherosclerosis. A novel dual-frequency imaging method is proposed in this paper for intravascular imaging applications. A probe combined two ultrasonic transducer elements with different center frequencies (36 MHz and 78 MHz) is designed and fabricated with PMN-PT single crystal material. It has the ability to balance both imaging depth and resolution, which are important imaging parameters for clinical test. A dual-channel imaging platform is also proposed for real-time imaging, and this platform has been proven to support programmable processing algorithms, flexible imaging control, and raw RF data acquisition for IVUS applications. Testing results show that the -6 dB axial and lateral imaging resolutions of low-frequency ultrasound are 78 and 132 μm, respectively. In terms of high-frequency ultrasound, axial and lateral resolutions are determined to be as high as 34 and 106 μm. In vitro intravascular imaging on healthy swine aorta is conducted to demonstrate the performance of the dual-frequency imaging method for IVUS applications. Copyright © 2014 Elsevier B.V. All rights reserved.

Refractory Hypertension Is not Attributable to Intravascular Fluid Retention as Determined by Intracardiac Volumes.

PubMed

Velasco, Alejandro; Siddiqui, Mohammed; Kreps, Eric; Kolakalapudi, Pavani; Dudenbostel, Tanja; Arora, Garima; Judd, Eric K; Prabhu, Sumanth D; Lloyd, Steven G; Oparil, Suzanne; Calhoun, David A

2018-06-04

Refractory hypertension (RfHTN) is an extreme phenotype of antihypertensive treatment failure defined as lack of blood pressure control with ≥5 medications, including a long-acting thiazide and a mineralocorticoid receptor antagonist. RfHTN is a subgroup of resistant hypertension (RHTN), which is defined as blood pressure >135/85 mm Hg with ≥3 antihypertensive medications, including a diuretic. RHTN is generally attributed to persistent intravascular fluid retention. It is unknown whether alternative mechanisms are operative in RfHTN. Our objective was to determine whether RfHTN is characterized by persistent fluid retention, indexed by greater intracardiac volumes determined by cardiac magnetic resonance when compared with controlled RHTN patients. Consecutive patients evaluated in our institution with RfHTN and controlled RHTN were prospectively enrolled. Exclusion criteria included advanced chronic kidney disease and masked or white coat hypertension. All enrolled patients underwent biochemical testing and cardiac magnetic resonance. The RfHTN group (n=24) was younger (mean age, 51.7±8.9 versus 60.6±11.5 years; P =0.003) and had a greater proportion of women (75.0% versus 43%; P =0.02) compared with the controlled RHTN group (n=30). RfHTN patients had a greater left ventricular mass index (88.3±35.0 versus 54.6±12.5 g/m 2 ; P <0.001), posterior wall thickness (10.1±3.1 versus 7.7±1.5 mm; P =0.001), and septal wall thickness (14.5±3.8 versus 10.0±2.2 mm; P <0.001). There was no difference in B-type natriuretic peptide levels and left atrial or ventricular volumes. Diastolic dysfunction was noted in RfHTN. Our findings demonstrate greater left ventricular hypertrophy without chamber enlargement in RfHTN, suggesting that antihypertensive treatment failure is not attributable to intravascular volume retention. © 2018 American Heart Association, Inc.

Efficacy of alfaxalone for intravascular anesthesia and euthanasia in blue crabs (Callinectes sapidus).

PubMed

Minter, Larry J; Harms, Craig A; Archibald, Kate E; Broadhurst, Heather; Bailey, Kate M; Christiansen, Emily F; Lewbart, Gregory A; Posner, Lysa P

2013-09-01

The objective of this study was to characterize the behavioral effects and changes in heart rate of four doses of alfaxalone delivered by intravascular injection to blue crabs (Callinectes sapidus). Thirty (male, n = 27; female, n = 3) blue crabs were randomly assigned to one of four treatment groups of alfaxalone: eight animals were assigned to each of the 5-, 10-, and 15-mg/kg treatment groups, and the remaining six animals were assigned to the 100-mg/kg group. Times for anesthetic induction and recovery periods were recorded. Righting reflex, defensive posturing, and heart rate were evaluated before, during, and after the anesthetic trial. Anesthesia was induced in all 14 animals consolidated into the high-dosage group (15 mg/kg [n = 8] and 100 mg/kg [n = 6]), which was significantly greater than 8 of 16 animals in the low-dosage group (5 mg/kg [n = 2] and 10 mg/kg [n = 6]). Median anesthesia induction time for all crabs was 0.4 min, with no significant difference in induction time between groups observed. Median recovery time was 9.4 min (n = 2), 6.1 min (n = 5), 11.3 min (n = 8), and 66.1 min (n = 5) for the 5-, 10-, 15-, and 100-mg/kg groups, respectively. Recovery times were significantly longer for crabs exposed to an induction dose of 100 mg/kg compared with the 10- and 15-mg/kg induction doses. A significant decrease in the median heart rate was observed between the baseline value and that observed at both induction and 5 min postinjection in the 100-mg/kg dose trial. Two mortalities were observed during the anesthesia trials (n = 1, 10 mg/kg; n = 1, 100 mg/kg), both associated with the autotomization of limbs. In summary, the intravascular administration of alfaxalone at 15 mg/kg provided rapid and reliable sedation, whereas alfaxalone administered at 100 mg/kg produced rapid and long lasting anesthesia.

The effects of ILLLI on peripheral blood T lymphocytes subpopulation & NK cells in psoriasis treatment

NASA Astrophysics Data System (ADS)

Zhu, Jing; Nie, Fan

2005-07-01

Objective: To research the effects of Intravascular low level laser irradiation (ILLLI) on the immulogic function of cells in treatment of psoriasis. Method: 49 patients suffered from psoriasis were treated by Intravascular low level laser irradiation (laser output power: 4-5mw, 1 hour per day, a course of treatment is 10 days). We checked the function of T lymphocyte subgroup and NK cell in peripheral blood between pre and post treatment. Results: 1.The mean value of CD3+ in post treatment is higher. P<0.05. Significant difference is showed between pre and post treatment 2. The mean value of CD4+ in post treatment dropped slightly while the mean value of CD4/CD8, NK cell in post treatment increased little, nearly approach the mean value of natural person. 3.The mean value of CD4+,CD8+,NK cell which is under 30% increased the percent obviously after the treatment; The mean value of CD4+,CD8+ u higher than 30% obviously drop the percent, P#0.05 and <0.01. Related statistical analysis showed significant and much significant difference between pre and post treatment. Conclusions: The low level laser irradiation (ILLLI) in treatment of psoriasis has bidirectional ajustive effect which can balance the immulogic function of cell.

The effect of ILLLI on peripheral blood SOD, MDA in psoriasis treatment

NASA Astrophysics Data System (ADS)

Zhu, Jing; Nie, Fan

2005-07-01

Objective: To research the effect of Intravascular low level laser irradiation (ILLLI) on the SOD,MDA in the treatment of psoriasis. Method :47 patients suffering from psoriasis from five groups were treated by Intravascular low level laser irradiation (power:4-5mw,1h per day, period of treatment: 10 days) .We checked the change of SOD,MDA peripheral blood in 10 normal people between pre and post treatment. Group A were treated by He-Ne laser combined with drug, group B were treated by semi-conductor laser combined with drug, group C were treated only by He-Ne laser, group D were treated only by semiconductor laser, group E were treated only by drug . Results: The levels of SOD in red cell of psoriatic patients from five groups after treatment were significantly lower than that of controlled group. The levels of SOD of them were significantly increased and nearly closed to that of controlled group; the levels of MDA in red cell of psoriatic patients from five groups after treatment were significantly higher than that of controlled group; the levels of MDA of them are decreased ,however, they were still not recovered to normal levels. Conclusions: ILLLI, both He-Ne laser and semiconductor laser, can activate SOD in psoriasis patients and enhance their ability of anti-oxidation.

Calpastatin Controls Polymicrobial Sepsis by Limiting Procoagulant Microparticle Release

PubMed Central

Gerotziafas, Grigoris; Byrnes, Colleen; Hu, Xuzhen; Perez, Joelle; Lévi, Charlène; Placier, Sandrine; Letavernier, Emmanuel; Leelahavanichkul, Asada; Haymann, Jean-philippe; Elalamy, Ismail; Miller, Jeffrey L.; Star, Robert A.; Yuen, Peter S. T.; Baud, Laurent

2012-01-01

Rationale: Sepsis, a leading cause of death worldwide, involves widespread activation of inflammation, massive activation of coagulation, and lymphocyte apoptosis. Calpains, calcium-activated cysteine proteases, have been shown to increase inflammatory reactions and lymphocyte apoptosis. Moreover, calpain plays an essential role in microparticle release. Objectives: We investigated the contribution of calpain in eliciting tissue damage during sepsis. Methods: To test our hypothesis, we induced polymicrobial sepsis by cecal ligation and puncture in wild-type (WT) mice and transgenic mice expressing high levels of calpastatin, a calpain-specific inhibitor. Measurements and Main Results: In WT mice, calpain activity increased transiently peaking at 6 hours after cecal ligation and puncture surgery. Calpastatin overexpression improved survival, organ dysfunction (including lung, kidney, and liver damage), and lymphocyte apoptosis. It decreased the sepsis-induced systemic proinflammatory response and disseminated intravascular coagulation, by reducing the number of procoagulant circulating microparticles and therefore delaying thrombin generation. The deleterious effect of microparticles in this model was confirmed by transferring microparticles from septic WT to septic transgenic mice, worsening their survival and coagulopathy. Conclusions: These results demonstrate an important role of the calpain/calpastatin system in coagulation/inflammation pathways during sepsis, because calpain inhibition is associated with less severe disseminated intravascular coagulation and better overall outcomes in sepsis. PMID:22268136

PROPOSAL AND APPLICATION OF A NOVEL DISSEMINATED INTRAVASCULAR COAGULATION SCORING SYSTEM IN THE FLORIDA MANATEE (TRICHECHUS MANATUS LATIROSTRIS).

PubMed

Barratclough, Ashley; Ball, Ray L; Floyd, Ruth Francis; Reep, Roger L; Conner, Bobbi J

2017-03-01

  Disseminated intravascular coagulopathy (DIC) is an acquired disorder of hemostasis resulting in activation of the coagulation and fibrinolytic pathways. It is reported secondarily to multiple disease processes and can be associated with increased mortality. Previous research at Tampa's Lowry Park Zoo (LPZ) demonstrated that Florida manatees ( Trichechus manatus latirostris) with cold stress syndrome (CSS) demonstrated thromboembolic disease. The object of this retrospective study was to establish the presence and clinical relevance of DIC in Florida manatees admitted to LPZ for rehabilitation from 07 March 2010 to 15 August 2015. A coagulation panel, including prothrombin time, partial thromboplastin time, platelet count, fibrinogen level, and D-dimer level was used to diagnose DIC. There were 100 cases identified in the study period: 35 trauma, 43 CSS, 17 secondary to harmful algae blooms (HAB), and five miscellaneous. Manatees with CSS had the highest incidence of DIC with 24 of 43 cases (56%) affected, followed by trauma with 18 of 35 cases (52%) affected. None of the manatees with HAB were found to have DIC. Manatees that developed DIC during rehabilitation or when DIC progressed did not survive. Due to the clinical implications of DIC, identifying its presence and recognizing its severity could improve clinical outcomes by enabling more intensive treatment protocols.

Differentiation of early from advanced coronary atherosclerotic lesions: systematic comparison of CT, intravascular US, and optical frequency domain imaging with histopathologic examination in ex vivo human hearts.

PubMed

Maurovich-Horvat, Pál; Schlett, Christopher L; Alkadhi, Hatem; Nakano, Masataka; Stolzmann, Paul; Vorpahl, Marc; Scheffel, Hans; Tanaka, Atsushi; Warger, William C; Maehara, Akiko; Ma, Shixin; Kriegel, Matthias F; Kaple, Ryan K; Seifarth, Harald; Bamberg, Fabian; Mintz, Gary S; Tearney, Guillermo J; Virmani, Renu; Hoffmann, Udo

2012-11-01

To establish an ex vivo experimental setup for imaging coronary atherosclerosis with coronary computed tomographic (CT) angiography, intravascular ultrasonography (US), and optical frequency domain imaging (OFDI) and to investigate their ability to help differentiate early from advanced coronary plaques. All procedures were performed in accordance with local and federal regulations and the Declaration of Helsinki. Approval of the local Ethics Committee was obtained. Overall, 379 histologic cuts from nine coronary arteries from three donor hearts were acquired, coregistered among modalities, and assessed for the presence and composition of atherosclerotic plaque. To assess the discriminatory capacity of the different modalities in the detection of advanced lesions, c statistic analysis was used. Interobserver agreement was assessed with the Cohen κ statistic. Cross sections without plaque at coronary CT angiography and with fibrous plaque at OFDI almost never showed advanced lesions at histopathologic examination (odds ratio [OR]: 0.02 and 0.06, respectively; both P<.0001), while mixed plaque at coronary CT angiography, calcified plaque at intravascular US, and lipid-rich plaque at OFDI were associated with advanced lesions (OR: 2.49, P=.0003; OR: 2.60, P=.002; and OR: 31.2, P<.0001, respectively). OFDI had higher accuracy for discriminating early from advanced lesions than intravascular US and coronary CT angiography (area under the receiver operating characteristic curve: 0.858 [95% confidence interval {CI}: 0.802, 0.913], 0.631 [95% CI: 0.554, 0.709], and 0.679 [95% CI: 0.618, 0.740]; respectively, P<.0001). Interobserver agreement was excellent for OFDI and coronary CT angiography (κ=0.87 and 0.85, respectively) and was good for intravascular US (κ=0.66). Systematic and standardized comparison between invasive and noninvasive modalities for coronary plaque characterization in ex vivo specimens demonstrated that coronary CT angiography and intravascular US are reasonably associated with plaque composition and lesion grading according to histopathologic findings, while OFDI was strongly associated. These data may help to develop initial concepts of sequential imaging strategies to identify patients with advanced coronary plaques. © RSNA, 2012

Monolithic CMUT on CMOS Integration for Intravascular Ultrasound Applications

PubMed Central

Zahorian, Jaime; Hochman, Michael; Xu, Toby; Satir, Sarp; Gurun, Gokce; Karaman, Mustafa; Degertekin, F. Levent

2012-01-01

One of the most important promises of capacitive micromachined ultrasonic transducer (CMUT) technology is integration with electronics. This approach is required to minimize the parasitic capacitances in the receive mode, especially in catheter based volumetric imaging arrays where the elements need to be small. Furthermore, optimization of the available silicon area and minimized number of connections occurs when the CMUTs are fabricated directly above the associated electronics. Here, we describe successful fabrication and performance evaluation of CMUT arrays for intravascular imaging on custom designed CMOS receiver electronics from a commercial IC foundry. The CMUT on CMOS process starts with surface isolation and mechanical planarization of the CMOS electronics to reduce topography. The rest of the CMUT fabrication is achieved by modifying a low temperature micromachining process through the addition of a single mask and developing a dry etching step to produce sloped sidewalls for simple and reliable CMUT to CMOS interconnection. This CMUT to CMOS interconnect method reduced the parasitic capacitance by a factor of 200 when compared with a standard wire bonding method. Characterization experiments indicate that the CMUT on CMOS elements are uniform in frequency response and are similar to CMUTs simultaneously fabricated on standard silicon wafers without electronics integration. Experiments on a 1.6 mm diameter dual-ring CMUT array with a 15 MHz center frequency show that both the CMUTs and the integrated CMOS electronics are fully functional. The SNR measurements indicate that the performance is adequate for imaging CTOs located 1 cm away from the CMUT array. PMID:23443701

Protein Z efficiently depletes thrombin generation in disseminated intravascular coagulation with poor prognosis.

PubMed

Lee, Nuri; Kim, Ji-Eun; Gu, Ja-Yoon; Yoo, Hyun Ju; Kim, Inho; Yoon, Sung-Soo; Park, Seonyang; Han, Kyou-Sup; Kim, Hyun Kyung

2016-01-01

Disseminated intravascular coagulation (DIC) is characterized by consumption of coagulation factors and anticoagulants. Thrombin generation assay (TGA) gives useful information about global hemostatic status. We developed a new TGA system that anticoagulant addition can deplete thrombin generation in plasma, which may reflect defective anticoagulant system in DIC. TGAs were measured on the calibrated automated thrombogram with and without thrombomodulin or protein Z in 152 patients who were suspected of having DIC, yielding four parameters including lag time, endogenous thrombin potential, peak thrombin and time-to-peak in each experiment. Nonsurvivors showed significantly prolonged lag time and time-to-peak in TGA-protein Z system, which was performed with added protein Z. In multivariate Cox regression analysis, lag time and time-to-peak in TGA system were significant independent prognostic factors. In TGA-protein Z system, lag time and time-to-peak were revealed as independent prognostic factors of DIC. Protein Z addition could potentiate its anticoagulant effect in DIC with poor prognosis, suggesting the presence of defective protein Z system. The prolonged lag time and time-to-peak in both TGA and TGA-protein Z systems are expected to be used as independent prognostic factors of DIC.

Experimental examination of a targeted hyperthermia system using inductively heated ferromagnetic microspheres in rabbit kidney

NASA Astrophysics Data System (ADS)

Jones, S. K.; Winter, J. G.

2001-02-01

It is known that significant heating can be generated by magnetic hysteresis effects in small ferromagnetic particles exposed to a rapidly alternating magnetic field. If such particles can be made to infiltrate the vascular bed surrounding a tumour by intravascular infusion then it may be possible to generate sufficient heating to destroy the tumour by hyperthermia. One of the constraints on such a technique is the limited amount of magnetic material that can be delivered to a tumour via the intravascular route and the consequent heating that can be induced by this material. Here, we report on a series of experiments in which doses of microspheres containing different amounts of ferromagnetic material were infused into rabbit kidneys via the renal artery with the aim of testing whether adequate tissue heating could be achieved using realistic concentrations of the embolised material. Heating rates were measured for each infused quantity under similar conditions with the animal alive and dead to examine the role of blood flow in the heating process. The results show that tissue temperatures above the therapeutic threshold of 42 °C can be readily achieved using this method with clinically relevant concentrations of microspheres in living tissue.

Analysis and compensation for the effect of the catheter position on image intensities in intravascular optical coherence tomography

NASA Astrophysics Data System (ADS)

Liu, Shengnan; Eggermont, Jeroen; Wolterbeek, Ron; Broersen, Alexander; Busk, Carol A. G. R.; Precht, Helle; Lelieveldt, Boudewijn P. F.; Dijkstra, Jouke

2016-12-01

Intravascular optical coherence tomography (IVOCT) is an imaging technique that is used to analyze the underlying cause of cardiovascular disease. Because a catheter is used during imaging, the intensities can be affected by the catheter position. This work aims to analyze the effect of the catheter position on IVOCT image intensities and to propose a compensation method to minimize this effect in order to improve the visualization and the automatic analysis of IVOCT images. The effect of catheter position is modeled with respect to the distance between the catheter and the arterial wall (distance-dependent factor) and the incident angle onto the arterial wall (angle-dependent factor). A light transmission model incorporating both factors is introduced. On the basis of this model, the interaction effect of both factors is estimated with a hierarchical multivariant linear regression model. Statistical analysis shows that IVOCT intensities are significantly affected by both factors with p<0.001, as either aspect increases the intensity decreases. This effect differs for different pullbacks. The regression results were used to compensate for this effect. Experiments show that the proposed compensation method can improve the performance of the automatic bioresorbable vascular scaffold strut detection.

Preintervention lesion remodelling affects operative mechanisms of balloon optimised directional coronary atherectomy procedures: a volumetric study with three dimensional intravascular ultrasound

PubMed Central

von Birgelen, C; Mintz, G; de Vrey, E A; Serruys, P; Kimura, T; Nobuyoshi, M; Popma, J; Leon, M; Erbel, R; de Feyter, P J

2000-01-01

AIMS—To classify atherosclerotic coronary lesions on the basis of adequate or inadequate compensatory vascular enlargement, and to examine changes in lumen, plaque, and vessel volumes during balloon optimised directional coronary atherectomy procedures in relation to the state of adaptive remodelling before the intervention.
DESIGN—29 lesion segments in 29 patients were examined with intravascular ultrasound before and after successful balloon optimised directional coronary atherectomy procedures, and a validated volumetric intravascular ultrasound analysis was performed off-line to assess the atherosclerotic lesion remodelling and changes in plaque and vessel volumes that occurred during the intervention. Based on the intravascular ultrasound data, lesions were classified according to whether there was inadequate (group I) or adequate (group II) compensatory enlargement.
RESULTS—There was no significant difference in patient and lesion characteristics between groups I and II (n = 10 and 19), including lesion length and details of the intervention. Quantitative coronary angiographic data were similar for both groups. However, plaque and vessel volumes were significantly smaller in group I than in II. In group I, 9 (4)% (mean (SD)) of the plaque volume was ablated, while in group II 16 (11)% was ablated (p = 0.01). This difference was reflected in a lower lumen volume gain in group I than in group II (46 (18) mm3 v 80 (49) mm3 (p < 0.02)).
CONCLUSIONS—Preintervention lesion remodelling has an impact on the operative mechanisms of balloon optimised directional coronary atherectomy procedures. Plaque ablation was found to be particularly low in lesions with inadequate compensatory vascular enlargement.


Keywords: intravascular ultrasound; ultrasonics; remodelling; coronary artery disease; atherectomy PMID:10648496

Descriptive Cadaveric Study Comparing the Accuracy of Ultrasound Versus Fluoroscopic Guidance for First Sacral Transforaminal Injections: A Comparison Study.

PubMed

Thompson, Bradley F; Pingree, Matthew J; Qu, Wenchun; Murthy, Naveen S; Lachman, Nirusha; Hurdle, Mark Friedrich

2018-04-01

Ultrasound is rarely used for guiding lumbosacral epidural steroid injections due to its technical limitations. For example, sonographic imaging lacks the ability to confirm epidural spread and identify vascular uptake. The perceived risk that these limitations pose to human subjects has precluded any large scale clinical trials to date. To compare the accuracy of ultrasound versus fluoroscopic guidance for first sacral transforaminal epidural injections. Cadaveric comparative study using dichotomous outcomes. A fluoroscopy suite and anatomic laboratory at an academic medical center. Four unembalmed adult human cadavers with no history of spinal surgery. Eight sites were injected twice by one interventionalist, using fluoroscopic and ultrasound guidance. In the fluoroscopy arm, contrast spread was assessed using computed tomography. In the ultrasound arm, latex spread was assessed using gross anatomic dissection. Any visible evidence of epidural spread constituted a positive result. Comparison of the success of obtaining epidural contrast flow was the primary outcome measure. Secondary outcome measures included average duration, rate of intravascular uptake, and quantity of intravascular uptake. All injections performed in both the ultrasound arm and the fluoroscopy arm had positive epidural spread. The average duration was 3.03 minutes with fluoroscopy and 4.76 minutes with ultrasound. The rate of intravascular uptake was 37.5% with fluoroscopy and 50% with ultrasound. Within the ultrasound arm, greater intravascular spread and duration variability were recorded. Although ultrasonography can provide reliable image guidance for cannulating the first sacral foramen in cadavers, it would have limited clinical utility due to its inability to visualize relevant neurovascular structures deep to the osseus roof and exclude intravascular uptake. IV. Copyright © 2018 American Academy of Physical Medicine and Rehabilitation. Published by Elsevier Inc. All rights reserved.

Intravascular hemolysis induced by the venom of the Eastern coral snake, Micrurus fulvius, in a mouse model: identification of directly hemolytic phospholipases A2.

PubMed

Arce-Bejarano, Ruth; Lomonte, Bruno; Gutiérrez, José María

2014-11-01

Intravascular hemolysis has been described in envenomings by the Eastern coral snake, Micrurus fulvius, in dogs. An experimental model of intravascular hemolysis was developed in mice after intravenous (i.v.) injection of M. fulvius venom. Within one hr, there was prominent hemolysis, associated with a drastic drop in hematocrit, morphological alterations of erythrocytes, hemoglobinemia, and hemoglobinuria. Hemoglobin was identified in urine by mass spectrometry. Histological sections of kidney revealed abundant hyaline casts, probably corresponding to hemoglobin. This effect was abrogated by p-bromophenacyl bromide, indicating that it is caused by phospholipases A2 (PLA2). A monospecific anti-Micrurus nigrocinctus antivenom neutralized hemolytic activity in vivo. When tested in vitro with erythrocytes of various species, a clear difference in susceptibility was observed. Mouse and dog erythrocytes showed the highest susceptibility, whereas human and rabbit erythrocytes were not affected at the experimental conditions tested. The higher susceptibility of dog and mouse erythrocytes correlates with a high ratio of phosphatidylcholine/sphingomyelin in erythrocyte plasma membrane. When mouse erythrocytes were subjected to mechanical stress, after incubation with venom, hemolysis increased significantly, suggesting that both phospholipid hydrolysis by PLA2s and mechanical stress associated with rheological factors are likely to contribute to cell lysis in vivo. Several PLA2s isolated from this venom reproduced the hemolytic effect, and the complete amino acid sequence of one of them (fraction 17), which also induces myotoxicity, is reported. Since very few PLA2s inducing intravascular hemolysis have been described from snake venoms, this enzyme is a valuable tool to identify the structural determinants of hemolytic activity. The mouse model described in this study may be useful to explore the pathophysiology of intravascular hemolysis. Copyright © 2014 Elsevier Ltd. All rights reserved.

Blood pressure regulation V: in vivo mechanical properties of precapillary vessels as affected by long-term pressure loading and unloading.

PubMed

Eiken, Ola; Mekjavic, Igor B; Kölegård, Roger

2014-03-01

Recent studies are reviewed, concerning the in vivo wall stiffness of arteries and arterioles in healthy humans, and how these properties adapt to iterative increments or sustained reductions in local intravascular pressure. A novel technique was used, by which arterial and arteriolar stiffness was determined as changes in arterial diameter and flow, respectively, during graded increments in distending pressure in the blood vessels of an arm or a leg. Pressure-induced increases in diameter and flow were smaller in the lower leg than in the arm, indicating greater stiffness in the arteries/arterioles of the leg. A 5-week period of intermittent intravascular pressure elevations in one arm reduced pressure distension and pressure-induced flow in the brachial artery by about 50%. Conversely, prolonged reduction of arterial/arteriolar pressure in the lower body by 5 weeks of sustained horizontal bedrest, induced threefold increases of the pressure-distension and pressure-flow responses in a tibial artery. Thus, the wall stiffness of arteries and arterioles are plastic properties that readily adapt to changes in the prevailing local intravascular pressure. The discussion concerns mechanisms underlying changes in local arterial/arteriolar stiffness as well as whether stiffness is altered by changes in myogenic tone and/or wall structure. As regards implications, regulation of local arterial/arteriolar stiffness may facilitate control of arterial pressure in erect posture and conditions of exaggerated intravascular pressure gradients. That increased intravascular pressure leads to increased arteriolar wall stiffness also supports the notion that local pressure loading may constitute a prime mover in the development of vascular changes in hypertension.

Look away: arterial and venous intravascular embolisation following shotgun injury.

PubMed

Vedelago, John; Dick, Elizabeth; Thomas, Robert; Jones, Brynmor; Kirmi, Olga; Becker, Jennifer; Alavi, Afshin; Gedroyc, Wladyslaw

2014-01-01

We describe two cases of intravascular embolization of shotgun pellets found distant to the entry site of penetrating firearm injury. The cases demonstrate antegrade embolization of a shotgun pellet from neck to right middle cerebral artery, and antegrade followed by retrograde venous embolization through the left lower limb to pelvis. Radiologists and Trauma Physicians should be aware that post shotgun injury, the likelihood of an embolised shot pellet is increased compared to other types of firearm missile injury, and should therefore search away from the site of injury to find such missiles. Shotgun pellets may travel in an antegrade or a retrograde intravascular direction - both were seen in these cases - and may not be clinically obvious. This underscores the importance of a meticuluous search through all images, including CT scout images, for evidence of their presence.

Intravascular ATP and the regulation of blood flow and oxygen delivery in humans.

PubMed

Crecelius, Anne R; Kirby, Brett S; Dinenno, Frank A

2015-01-01

Regulation of vascular tone is a complex response that integrates multiple signals that allow for blood flow and oxygen supply to match oxygen demand appropriately. Here, we discuss the potential role of intravascular adenosine triphosphate (ATP) as a primary factor in these responses and put forth the hypothesis that deficient ATP release contributes to impairments in vascular control exhibited in aged and diseased populations.

Blood coagulation status of small-for-dates and postmature infants.

PubMed Central

Perlman, M; Dvilansky, A

1975-01-01

In a prospective study of blood coagulation status in small-for-dates and postmature infants there was often evidence of intravascular coagulation. Abnormal coagulation findings correlated with the degree of growth retardation and with the degree of postmaturity. Macroscopical placental infarction and neonatal polycythaemia were associated with coagulation abnormalities; asphyxia, however, was not. Intravascular coagulation may be an additional hazard to small-for-dates and postmature infants. PMID:1170815

Intravascular haemolysis during prolonged running on asphalt and natural grass in long and middle distance runners.

PubMed

Janakiraman, Kamal; Shenoy, Shweta; Sandhu, Jaspal Singh

2011-09-01

Surface features such as uneven playing surfaces, low impact absorption capacity and inappropriate friction/traction characteristics are connected with injury prevalence whereas force impact during foot strike has been suggested to be an important mechanism of intravascular haemolysis during running. We aimed to evaluate intravascular haemolysis during running and compare the effect of running on two different types of surfaces on haemolysis. We selected two surfaces (asphalt and grass) on which these athletes usually run. Participants were randomly assigned to group A (asphalt) or group B (grass) with 10 athletes in each group. Each athlete completed one hour of running at the calculated target heart rate (60-70%). Venous blood samples were collected before and immediately after running. We measured unconjugated bilirubin (UBR) (mg · dl(-1)), lactate dehydrogenase (LDH) (μ · ml(-1)), haemoglobin (g · l(-1)) and serum ferritin (ng · ml(-1)) as indicators of haemolysis. Athletes who ran on grass demonstrated an increase in the haematological parameters (UBR: P < 0.01, LDH: P < 0.05) when compared to athletes who ran on asphalt (UBR: P < 0.05, LDH: P = 0.241). Our findings indicate that intravascular haemolysis occurs significantly after prolonged running. Furthermore, we conclude that uneven grass surface results in greater haemolysis compared to asphalt road.

The lateral neostriatum is necessary for compensatory ingestive behaviour after intravascular dehydration in female rats.

PubMed

Lelos, M J; Harrison, D J; Rosser, A E; Dunnett, S B

2013-12-01

Aberrant striatal function results in an array of physiological symptoms, including impaired consummatory and regulatory behaviours, which can lead to weight loss and dehydration. It was hypothesised, therefore, that cell loss in the neostriatum may contribute to altered fluid intake by regulating physiological signals related to dehydration status. To test this theory, rats with lesions of the lateral neostriatum and sham controls underwent a series of physiological challenges, including the experimental induction of intracellular and intravascular dehydration. No baseline differences in prandial or non-prandial drinking were observed, nor were differences in locomotor activity evident between groups. Furthermore, intracellular dehydration increased water intake in lesion rats in a manner comparable to sham rats. Interestingly, a specific impairment was evident in lesion rats after subcutaneous injection of poly-ethylene glycol was used to induce intravascular dehydration, such that lesion rats failed to adapt their water intake to this physiological change. The results suggest that the striatal lesions resulted in regulatory dysfunction by impairing motivational control over compensatory ingestive behaviour after intravascular hydration, while the physiological signals related to dehydration remain intact. Loss of these cells in neurodegenerative disorders, such Huntington's disease, may contribute to regulatory changes evident in the course of the disease. Copyright © 2013 Elsevier Ltd. All rights reserved.

Hydrophilic Polymer Embolism: Implications for Manufacturing, Regulation, and Postmarket Surveillance of Coated Intravascular Medical Devices.

PubMed

Mehta, Rashi I; Mehta, Rupal I

2018-03-19

Hydrophilic polymers are ubiquitously applied as surface coatings on catheters and intravascular medical technologies. Recent clinical literature has heightened awareness on the complication of hydrophilic polymer embolism, the phenomenon wherein polymer coating layers separate from catheter and device surfaces, and may be affiliated with a range of unanticipated adverse reactions. Significant system barriers have limited and delayed reporting on this iatrogenic complication, the full effects of which remain underrecognized by healthcare providers and manufacturers of various branded devices. In 2015, the United States Food and Drug Administration acknowledged rising clinical concerns and stated that the agency would work with stakeholders to further evaluate gaps that exist in current national and international device standards for coated intravascular medical technologies. The present article reviews current knowledge on this complication as well as factors that played a role in delaying detection and dissemination of information and new knowledge once hazards and clinical risks were identified. Furthermore, organ-specific effects and adverse reaction patterns are summarized, along with implications for device manufacturing, safety assurance, and regulation. Qualitative and quantitative particulate testing are needed to optimize coated intravascular device technologies. Moreover, general enhanced processes for medical device surveillance are required for timely adverse event management and to ensure patient safety.

Characterization of coronary plaques with combined use of intravascular ultrasound, virtual histology and optical coherence tomography

PubMed Central

Sánchez-Elvira, Guillermo; Coma-Canella, Isabel; Artaiz, Miguel; Páramo, José Antonio; Barba, Joaquín; Calabuig, José

2010-01-01

According to post-mortem studies, luminal thrombosis occurs from plaque rupture, erosion and calcified nodules. In vivo studies have found thin cap fibroatheroma (TCFA) as the main vulnerable lesion, prone to rupture. Few data about other post-mortem lesions have been reported in vivo. Our main objective is to characterize in vivo the coronary plaques with intravascular ultrasound-virtual histology (IVUS-VH) and optical coherence tomography (OCT), in order to detect not only thin cap fibroatheroma (TCFA), but also other possible vulnerable lesions. The secondary objective is to correlate these findings with clinical and analytical data. Twenty-five patients (18 stable) submitted to coronary angiography were included in this pilot study. After angiography, the three vessels were studied (when possible) with IVUS-VH and OCT. Plaque characteristics were correlated with clinical and analytical data. Forty-six lesions were analyzed. IVUS-VH detected significant necrotic core in 15 (3 were definite TCFA). OCT detected TCFA in 10 lesions, erosion in 6, thrombus in 5 and calcified nodule in 8. Possible vulnerable lesion was found in 61% of stable and 57% of unstable patients. Erosions and calcified nodules were only found in stable patients. Those with significant necrotic core had higher body mass index (P=0.016), higher levels of hs-CRP (P=0.019) and triglycerides (P=0.040). The higher the levels of hs-CRP, the larger the size of the necrotic core (r=0.69, P=0.003). Lesions with characteristics of vulnerability were detected by IVUS-VH and OCT in more than 50% of stable and unstable coronary patients. A significant necrotic core was mainly correlated with higher hs-CRP. PMID:21977297

Effects of buprenorphine in the adrenal, thyroid, and cytokine intra-operative responses in a rat model (Rattus norvegicus): a preliminary study

PubMed Central

Félix, Nuno M; Leal, Rodolfo O; Goy-Thollot, I; Walton, Ronald S; Gil, Solange A; Mateus, Luísa M; Matos, Ana S; Niza, Maria M R E

2017-01-01

Objective(s): Buprenorphine is a common analgesic in experimental research, due to effectiveness and having few side-effects, including a limited influence in the immune and endocrine systems. However, how buprenorphine affects cytokine levels and the adrenal and thyroid response during general anesthesia and surgery is incompletely understood. This study aimed to assess whether buprenorphine modulated significantly those responses in rats submitted to general anesthesia, mechanical ventilation, and surgical insertion of intravascular catheters. Materials and Methods: Animals were anesthetized with isoflurane, mechanically ventilated, and surgically instrumented for carotid artery and the femoral vein catheter placement. The test group (n=16), received buprenorphine subcutaneously before surgery, whereas the control group (n=16) received normal saline. Blood sampling to determine plasma levels of adrenocorticotropic hormone (ACTH), corticosterone (CS), total thyroxine (TT4), total triiodothyronine (TT3), thyroid-stimulating hormone (TSH), TNF-α, IL6, IL10, TNF-α, IL6, and IL10 mRNA was performed at 10 min after completion of all surgical procedures and at 90, 150, 240, and 300 min thereafter, with the animals still anesthetized and with mechanical ventilation. Results: Buprenorphine-treated animals had higher levels of ACTH, CS, and TT4 at several time points (P<0.05) and TSH and TT3 at all-time points (P<0.05). They also had increased IL10, TNF-α, and IL10 mRNA levels. Conclusion: In this model, buprenorphine significantly modulated the intra-operative cytokine and endocrine response to anesthesia, mechanical ventilation, and surgical placement of intravascular catheters. The mechanism and significance of these findings remain undetermined. Researchers should be aware of these effects when considering the use of buprenorphine for analgesic purposes. PMID:28804607

Experiments on the genesis of bubbles as a result of rapid decompression

PubMed Central

Lever, M. J.; Miller, K. W.; Paton, W. D. M.; Smith, E. B.

1966-01-01

1. The time course of intravascular bubble formation in mice after rapid decompression from 150 Lb/sq. in. has been followed in vivo in a flap preparation of thoracic and abdominal skin. 2. Gas appeared first in the arteries, moving distally after a latent period of 3 min or more. Then bubbles appeared, moving centrally, in the venous system. 3. The arterial bubbles could not be attributed to air forced into the circulation from the lungs or lumen of the gut. ImagesFig. 1 PMID:5912215

High grade primary adrenal intravascular large B-cell lymphoma manifesting as Addison disease.

PubMed

Venizelos, I; Venizelos, J; Tamiolakis, D; Lambropoulou, M; Alexiadis, G; Petrakis, G; Papadopoulos, N

2007-08-01

We report a rare case of a 68 aged male who presented with adrenal failure and was diagnosed of high grade large B-cell lymphoma primarily arising in the adrenal glands. The patient was administrated with additional chemotherapy but he passed away 7 months later due to infection in the lungs. Intravascular lymphoma should be suspected in patients with bilateral adrenal masses who present with rapidly progressive adrenal insufficiency.

Biocompatibility study of plasma-coated nitinol (NiTi alloy) stents.

PubMed

Wang, G; Shen, Y; Cao, Y; Yu, Q; Guidoin, R

2007-12-01

The authors aimed to assess the surface modification effects of plasma coatings on biocompatibility of nitinol intravascular stent in terms of anticoagulation, haemocytolysis rate, hydrophilicity, cytotoxicity and so on. In order to improve their surface adhesive properties to endothelial cells, NiTi alloy intravascular stents were treated and coated using a low-temperature plasma deposition technique. It was found that plasma coating changed the surface morphology of the stents to a micron-level surface roughness in the range of 1-5 microm. In comparison with the untreated control, the plasma-treated NiTi alloy intravascular stents showed increased surface hydrophilicity and enhanced anticoagulation property. Testing results on plasma-coated NiTi stents indicated that they complied with the standard of national biologic safety evaluation of medical apparatus and instrument (GB/T16886-1997, People's Republic of China) in terms of haemocytolysis rate, cytotoxicity and pyretogen.

Molecular intravascular imaging approaches for atherosclerosis.

PubMed

Press, Marcella Calfon; Jaffer, Farouc A

2014-10-01

Coronary artery disease (CAD) is an inflammatory process that results in buildup of atherosclerosis, typically lipid-rich plaque in the arterial wall. Progressive narrowing of the vessel wall and subsequent plaque rupture can lead to myocardial infarction and death. Recent advances in intravascular fluorescence imaging techniques have provided exciting coronary artery-targeted platforms to further characterize the molecular changes that occur within the vascular wall as a result of atherosclerosis and following coronary stent-induced vascular injury. This review will summarize exciting recent developments in catheter-based imaging of coronary arterial-sized vessels; focusing on two-dimensional near-infrared fluorescence imaging (NIRF) molecular imaging technology as an approach to specifically identify inflammation and fibrin directly within coronary artery-sized vessels. Intravascular NIRF is anticipated to provide new insights into the in vivo biology underlying high-risk plaques, as well as high-risks stents prone to stent restenosis or stent thrombosis.

SIADH and partial hypopituitarism in a patient with intravascular large B-cell lymphoma: a rare cause of a common presentation

PubMed Central

Akhtar, Simeen; Cheesman, Edmund; Jude, Edward B

2013-01-01

Hyponatraemia is a very common electrolyte abnormality with varied presenting features depending on the underlying cause. The authors report the case of a 75-year-old, previously fit, gentleman who presented with weight loss, lethargy and blackouts. He required four admissions to the hospital over an 8-month period. Investigations revealed persistent hyponatraemia consistent with a diagnosis of syndrome of inappropriate antidiuretic hormone secretion, macrocytic anaemia and partial hypopituitarism. Unfortunately, all other investigations that were performed failed to identify the underlying cause and a diagnosis of intravascular large B-cell lymphoma was only confirmed following postmortem studies. The authors recommend that endocrinologists should be involved at the outset in the management of patients with persistent hyponatraemia and that intravascular large B-cell lymphoma should be considered in the differential diagnosis of hyponatraemia. PMID:23362070

Intravascular photoacoustic imaging at 35 and 80 MHz

PubMed Central

Li, Xiang; Wei, Wei; Shung, K. Kirk

2012-01-01

Abstract. The catheter-based intravascular photoacoustic (IVPA) imaging for diagnosing atherosclerosis, which can provide optical absorption contrast of the arterial wall besides acoustic scattering contrast from the conventional intravascular ultrasound (IVUS) imaging, has been intensively researched recently. The resolution of IVPA is determined by the frequency bandwidth of an ultrasonic transducer. Higher resolution can be achieved by increasing the transducer’s working frequency and bandwidth. We introduce IVPA imaging at 35 and 80 MHz by using newly designed integrated IVUS/IVPA probes. This is the first time IVPA has been achieved as high as 80 MHz. Six-micrometer tungsten wires were imaged to evaluate the probes’ spatial resolutions and beam patterns. Healthy rabbit aorta was imaged in vitro. Imaging results show that IVPA has superior contrast over IVUS in identifying the arterial wall, and IVPA at 80 MHz demonstrates extraordinary resolution (35 μm) compared to 35 MHz. PMID:23224004

Intravascular photoacoustic imaging of exogenously labeled atherosclerotic plaque through luminal blood

NASA Astrophysics Data System (ADS)

Yeager, Doug; Karpiouk, Andrei; Wang, Bo; Amirian, James; Sokolov, Konstantin; Smalling, Richard; Emelianov, Stanislav

2012-10-01

Combined intravascular ultrasound and intravascular photoacoustic (IVUS/IVPA) imaging has been previously established as a viable means for assessing atherosclerotic plaque morphological and compositional characteristics using both endogenous and exogenous contrast. In this study, IVUS/IVPA imaging of atherosclerotic rabbit aortas following systemic injection of gold nanorods (AUNRs) with peak absorbance within the tissue optical window is performed. Ex vivo imaging results reveal a high photoacoustic signal from localized AUNRs in regions with atherosclerotic plaques. Corresponding histological staining further confirms the preferential extravasation of AUNRs in atherosclerotic regions with compromised luminal endothelium and acute inflammation. The ability to detect AUNRs using combined IVUS and photoacoustic imaging in the presence of luminal saline and luminal blood is evaluated using both spectroscopic and single wavelength IVPA imaging techniques. Results demonstrate that AUNR detection within the arterial wall can be achieved using both methods, even in the case of imaging through luminal blood.

Pulmonary microvascular cytology can detect tumor cells of intravascular lymphoma.

PubMed

Ishiguro, Takashi; Takayanagi, Noboru; Yanagisawa, Tsutomu; Kagiyama, Naho; Saito, Hiroo; Sugita, Yutaka; Kojima, Masaru

2009-01-01

A 68-year-old man was admitted to our hospital for indistinct consciousness, progressive dyspnea, night sweats and fever of 2 weeks duration. Hypoxemia, thrombocytopenia, and elevated serum lactate dehydrogenase were found. Computed tomography was negative except for a small bilateral pleural effusion. Chest perfusion scintigraphy showed inhomogeneous perfusion thought unlikely to be pulmonary artery thromboembolism. Intravascular large B-cell lymphoma was suspected, and a pulmonary microvascular cytology specimen was obtained that contained numerous large lymphoma cells. Because the patient's condition was rapidly deteriorating, we started chemotherapy on the basis of the pulmonary microvascular cytology findings, and he improved. Later, atypical lymphocytes similar to those in the pulmonary microvascular cytology specimen were found in a bone marrow specimen. He was diagnosed as having diffuse large B-cell lymphoma. Because lymphoma cells were found in the pulmonary microvasculature, intravascular lymphoma was also diagnosed. Pulmonary microvascular cytology was helpful to detect lymphoma cells in the pulmonary microvasculature.

Skin-like biosensor system via electrochemical channels for noninvasive blood glucose monitoring.

PubMed

Chen, Yihao; Lu, Siyuan; Zhang, Shasha; Li, Yan; Qu, Zhe; Chen, Ying; Lu, Bingwei; Wang, Xinyan; Feng, Xue

2017-12-01

Currently, noninvasive glucose monitoring is not widely appreciated because of its uncertain measurement accuracy, weak blood glucose correlation, and inability to detect hyperglycemia/hypoglycemia during sleep. We present a strategy to design and fabricate a skin-like biosensor system for noninvasive, in situ, and highly accurate intravascular blood glucose monitoring. The system integrates an ultrathin skin-like biosensor with paper battery-powered electrochemical twin channels (ETCs). The designed subcutaneous ETCs drive intravascular blood glucose out of the vessel and transport it to the skin surface. The ultrathin (~3 μm) nanostructured biosensor, with high sensitivity (130.4 μA/mM), fully absorbs and measures the glucose, owing to its extreme conformability. We conducted in vivo human clinical trials. The noninvasive measurement results for intravascular blood glucose showed a high correlation (>0.9) with clinically measured blood glucose levels. The system opens up new prospects for clinical-grade noninvasive continuous glucose monitoring.

Skin-like biosensor system via electrochemical channels for noninvasive blood glucose monitoring

PubMed Central

Chen, Yihao; Lu, Siyuan; Zhang, Shasha; Li, Yan; Qu, Zhe; Chen, Ying; Lu, Bingwei; Wang, Xinyan; Feng, Xue

2017-01-01

Currently, noninvasive glucose monitoring is not widely appreciated because of its uncertain measurement accuracy, weak blood glucose correlation, and inability to detect hyperglycemia/hypoglycemia during sleep. We present a strategy to design and fabricate a skin-like biosensor system for noninvasive, in situ, and highly accurate intravascular blood glucose monitoring. The system integrates an ultrathin skin-like biosensor with paper battery–powered electrochemical twin channels (ETCs). The designed subcutaneous ETCs drive intravascular blood glucose out of the vessel and transport it to the skin surface. The ultrathin (~3 μm) nanostructured biosensor, with high sensitivity (130.4 μA/mM), fully absorbs and measures the glucose, owing to its extreme conformability. We conducted in vivo human clinical trials. The noninvasive measurement results for intravascular blood glucose showed a high correlation (>0.9) with clinically measured blood glucose levels. The system opens up new prospects for clinical-grade noninvasive continuous glucose monitoring. PMID:29279864

Techniques for Intravascular Foreign Body Retrieval

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

Woodhouse, Joe B.; Uberoi, Raman, E-mail: raman.uberoi@orh.nhs.uk

2013-08-01

As endovascular therapies increase in frequency, the incidence of lost or embolized foreign bodies is increasing. The presence of an intravascular foreign body (IFB) is well recognized to have the potential to cause serious complications. IFB can embolize and impact critical sites such as the heart, with subsequent significant morbidity or mortality. Intravascular foreign bodies most commonly result from embolized central line fragments, but they can originate from many sources, both iatrogenic and noniatrogenic. The percutaneous approach in removing an IFB is widely perceived as the best way to retrieve endovascular foreign bodies. This minimally invasive approach has a highmore » success rate with a low associated morbidity, and it avoids the complications related to open surgical approaches. We examined the characteristics, causes, and incidence of endovascular embolizations and reviewed the various described techniques that have been used to facilitate subsequent explantation of such materials.« less

Risk factors associated with short-term outcome and development of perioperative complications in dogs undergoing surgery because of gastric dilatation-volvulus: 166 cases (1992-2003).

PubMed

Beck, Jennifer J; Staatz, Andrew J; Pelsue, Davyd H; Kudnig, Simon T; MacPhail, Catriona M; Seim, Howard B; Monnet, Eric

2006-12-15

To evaluate risk factors associated with death and development of perioperative complications in dogs undergoing surgery for treatment of gastric dilatation-volvulus (GDV). Retrospective case series. 166 dogs. Records of dogs with confirmed GDV that underwent surgery were reviewed. Logistic regression was performed to identify factors associated with development of complications (ie, hypotension, arrhythmias, gastric necrosis necessitating gastrectomy, disseminated intravascular coagulation, peritonitis, sepsis, postoperative dilatation, postoperative vomiting, and incisional problems) and with short-term outcome (ie, died vs survived to the time of suture removal). Short-term mortality rate was 16.2% (27/166). Risk factors significantly associated with death prior to suture removal were clinical signs for > 6 hours prior to examination, combined splenectomy and partial gastrectomy, hypotension at any time during hospitalization, peritonitis, sepsis, and disseminated intravascular coagulation. Partial gastrectomy was not a significant risk factor for death but was for peritonitis, disseminated intravascular coagulation, sepsis, and arrhythmias. Age, gastrectomy, and disseminated intravascular coagulation were risk factors for development of hypotension. Use of a synthetic colloid or hypertonic saline solution was associated with a significantly decreased risk of hypotension. Results suggest that the prognosis for dogs undergoing surgery because of GDV is good but that certain factors are associated with an increased risk that dogs will develop perioperative complications or die.

Orbital Atherectomy Plaque Modification Assessment of the Femoropopliteal Artery Via Intravascular Ultrasound (TRUTH Study)

PubMed Central

Zavlunova, Susanna; Attubato, Michael J.; Martinsen, Brad J.; Mintz, Gary S.; Maehara, Akiko

2015-01-01

Objective: The Tissue Removal Assessment with Ultrasound of the SFA and Popliteal (TRUTH) study assessed the performance of the orbital atherectomy system (OAS) to treat femoropopliteal arteries, including determining its effect on plaque removal. Methods: Patients with symptomatic femoropopliteal peripheral arterial disease were treated with the OAS followed by adjunctive balloon angioplasty (BA). Intravascular ultrasound (IVUS) images were collected pre- and post-OAS and post-OAS BA. Patients were followed through 12 months post-procedure. Results: Twenty-nine lesions were treated with OAS-BA in 25 patients. The mean maximum balloon inflation pressure was 5.2 ± 1.2 atm. Virtual histology IVUS (VH-IVUS) analysis revealed at the maximum calcium ablation site that calcium reduction was responsible for 86% of the lumen area increase. The minimum lumen area increased from 4.0 mm2 to 9.1 mm2 (<.0001), and the percentage of area stenosis decreased from 76.9% to 43.0% (<.0001) after OAS-BA. At 12 months, the target lesion revascularization rate was 8.2%, and ankle–brachial index and Rutherford classification improved significantly from baseline through follow-up. Conclusion: The VH-IVUS analysis reveals that OAS modifies the calcified component of the plaque burden. It is hypothesized that calcium modification by OAS changes the lesion compliance, allowing for low pressure adjunctive BA. The clinical outcomes were favorable through 12-month follow-up. PMID:26490645

Predictors and Long-Term Clinical Impact of Acute Stent Malapposition: An Assessment of Dual Antiplatelet Therapy With Drug-Eluting Stents (ADAPT-DES) Intravascular Ultrasound Substudy.

PubMed

Wang, Bin; Mintz, Gary S; Witzenbichler, Bernhard; Souza, Cristiano F; Metzger, D Christopher; Rinaldi, Michael J; Duffy, Peter L; Weisz, Giora; Stuckey, Thomas D; Brodie, Bruce R; Matsumura, Mitsuaki; Yamamoto, Myong-Hwa; Parvataneni, Rupa; Kirtane, Ajay J; Stone, Gregg W; Maehara, Akiko

2016-12-22

The impact of acute stent malapposition (ASM) on long-term clinical outcomes in patients undergoing percutaneous coronary intervention is still controversial. We sought to evaluate predictors and long-term clinical outcomes of ASM. ADAPT-DES (Assessment of Dual Antiplatelet Therapy With Drug-Eluting Stents) was a prospective multicenter study of 8663 patients undergoing percutaneous coronary intervention using drug-eluting stents. In a prespecified intravascular ultrasound-guided substudy, 2072 patients with 2446 culprit lesions had post-percutaneous coronary intervention intravascular ultrasound and were classified according to the presence or absence of ASM. After intravascular ultrasound-guided percutaneous coronary intervention, the overall prevalence of ASM after successful drug-eluting stents implantation was 14.4% per patient and 12.6% per lesion. Compared to lesions without ASM, lesions with ASM had larger in-stent lumen areas, larger stent areas, and larger in-stent vessel areas. A larger mean plaque area along with more attenuated plaque was observed in lesions with ASM versus lesions without ASM. Lesions with ASM had greater proximal and distal reference lumen areas and more distal, but not proximal, reference calcium compared to lesions without ASM. At 2-year follow-up, there was no significant difference in the incidence of cardiac death; myocardial infarction; early, late, or very late stent thrombosis; or clinically driven target lesion revascularization in patients with ASM versus those without ASM. Furthermore, ASM was not an independent predictor of 2-year major adverse cardiac events or target lesion revascularization even when forced into the multivariate model. In patients treated with intravascular ultrasound-guided drug-eluting stents implantation, ASM was not associated with adverse clinical events during long-term follow-up including, but not limited to, stent thrombosis. URL: https://www.clinicaltrials.gov. Unique identifier: NCT00638794. © 2016 The Authors. Published on behalf of the American Heart Association, Inc., by Wiley Blackwell.

Double-cladding-fiber-based detection system for intravascular mapping of fluorescent molecular probes

NASA Astrophysics Data System (ADS)

Razansky, R. Nika; Rozental, Amir; Mueller, Mathias S.; Deliolanis, Nikolaos; Jaffer, Farouc A.; Koch, Alexander W.; Ntziachristos, Vasilis

2011-03-01

Early detection of high-risk coronary atherosclerosis remains an unmet clinical challenge. We have previously demonstrated a near-infrared fluorescence catheter system for two-dimensional intravascular detection of fluorescence molecular probes [1]. In this work we improve the system performance by introducing a novel high resolution sensor. The main challenge of the intravascular sensor is to provide a highly focused spot at an application relevant distance on one hand and a highly efficient collection of emitted light on the other. We suggest employing a double cladding optical fiber (DCF) in combination with focusing optics to provide a sensor with both highly focused excitation light and highly efficient fluorescent light collection. The excitation laser is coupled into the single mode core of DCF and guided through a focusing element and a right angle prism. The resulting side-fired beam exhibits a small spot diameter (50 μm) throughout a distance of up to 2 mm from the sensor. This is the distance of interest for intravascular coronary imaging application, determined by an average human coronary artery diameter. At the blood vessel wall, an activatable fluorescence molecular probe is excited in the diseased lesions. Next light of slightly shifted wavelength emits only in the places of the inflammations, associated with dangerous plaques [2]. The emitted light is collected by the cladding of the DCF, with a large collection angle (NA=0.4). The doublecladding acts as multimodal fiber and guides the collected light to the photo detection elements. The sensor automatically rotates and pulled-back, while each scanned point is mapped according to the amount of detected fluorescent emission. The resulting map of fluorescence activity helps to associate the atherosclerotic plaques with the inflammation process. The presented detection system is a valuable tool in the intravascular plaque detection and can help to differentiate the atherosclerotic plaques based on their biological activity, identify the ones that prone to rupture and therefore require more medical attention.

Mechanical effects of muscle contraction increase intravascular ATP draining quiescent and active skeletal muscle in humans

PubMed Central

Crecelius, Anne R.; Kirby, Brett S.; Richards, Jennifer C.

2013-01-01

Intravascular adenosine triphosphate (ATP) evokes vasodilation and is implicated in the regulation of skeletal muscle blood flow during exercise. Mechanical stresses to erythrocytes and endothelial cells stimulate ATP release in vitro. How mechanical effects of muscle contractions contribute to increased plasma ATP during exercise is largely unexplored. We tested the hypothesis that simulated mechanical effects of muscle contractions increase [ATP]venous and ATP effluent in vivo, independent of changes in tissue metabolic demand, and further increase plasma ATP when superimposed with mild-intensity exercise. In young healthy adults, we measured forearm blood flow (FBF) (Doppler ultrasound) and plasma [ATP]v (luciferin-luciferase assay), then calculated forearm ATP effluent (FBF×[ATP]v) during rhythmic forearm compressions (RFC) via a blood pressure cuff at three graded pressures (50, 100, and 200 mmHg; Protocol 1; n = 10) and during RFC at 100 mmHg, 5% maximal voluntary contraction rhythmic handgrip exercise (RHG), and combined RFC + RHG (Protocol 2; n = 10). [ATP]v increased from rest with each cuff pressure (range 144–161 vs. 64 ± 13 nmol/l), and ATP effluent was graded with pressure. In Protocol 2, [ATP]v increased in each condition compared with rest (RFC: 123 ± 33; RHG: 51 ± 9; RFC + RHG: 96 ± 23 vs. Mean Rest: 42 ± 4 nmol/l; P < 0.05), and ATP effluent was greatest with RFC + RHG (RFC: 5.3 ± 1.4; RHG: 5.3 ± 1.1; RFC + RHG: 11.6 ± 2.7 vs. Mean Rest: 1.2 ± 0.1 nmol/min; P < 0.05). We conclude that the mechanical effects of muscle contraction can 1) independently elevate intravascular ATP draining quiescent skeletal muscle without changes in local metabolism and 2) further augment intravascular ATP during mild exercise associated with increases in metabolism and local deoxygenation; therefore, it is likely one stimulus for increasing intravascular ATP during exercise in humans. PMID:23429876

Understanding the heterogeneity in volume overload and fluid distribution in decompensated heart failure is key to optimal volume management: role for blood volume quantitation.

PubMed

Miller, Wayne L; Mullan, Brian P

2014-06-01

This study sought to quantitate total blood volume (TBV) in patients hospitalized for decompensated chronic heart failure (DCHF) and to determine the extent of volume overload, and the magnitude and distribution of blood volume and body water changes following diuretic therapy. The accurate assessment and management of volume overload in patients with DCHF remains problematic. TBV was measured by a radiolabeled-albumin dilution technique with intravascular volume, pre-to-post-diuretic therapy, evaluated at hospital admission and at discharge. Change in body weight in relation to quantitated TBV was used to determine interstitial volume contribution to total fluid loss. Twenty-six patients were prospectively evaluated. Two patients had normal TBV at admission. Twenty-four patients were hypervolemic with TBV (7.4 ± 1.6 liters) increased by +39 ± 22% (range, +9.5% to +107%) above the expected normal volume. With diuresis, TBV decreased marginally (+30 ± 16%). Body weight declined by 6.9 ± 5.2 kg, and fluid intake/fluid output was a net negative 8.4 ± 5.2 liters. Interstitial compartment fluid loss was calculated at 6.2 ± 4.0 liters, accounting for 85 ± 15% of the total fluid reduction. TBV analysis demonstrated a wide range in the extent of intravascular overload. Dismissal measurements revealed marginally reduced intravascular volume post-diuretic therapy despite large reductions in body weight. Mobilization of interstitial fluid to the intravascular compartment with diuresis accounted for this disparity. Intravascular volume, however, remained increased at dismissal. The extent, composition, and distribution of volume overload are highly variable in DCHF, and this variability needs to be taken into account in the approach to individualized therapy. TBV quantitation, particularly serial measurements, can facilitate informed volume management with respect to a goal of treating to euvolemia. Copyright © 2014 American College of Cardiology Foundation. Published by Elsevier Inc. All rights reserved.

Critical role of non-muscle myosin light chain kinase in thrombin-induced endothelial cell inflammation and lung PMN infiltration.

PubMed

Fazal, Fabeha; Bijli, Kaiser M; Murrill, Matthew; Leonard, Antony; Minhajuddin, Mohammad; Anwar, Khandaker N; Finkelstein, Jacob N; Watterson, D Martin; Rahman, Arshad

2013-01-01

The pathogenesis of acute lung injury (ALI) involves bidirectional cooperation and close interaction between inflammatory and coagulation pathways. A key molecule linking coagulation and inflammation is the procoagulant thrombin, a serine protease whose concentration is elevated in plasma and lavage fluids of patients with ALI and acute respiratory distress syndrome (ARDS). However, little is known about the mechanism by which thrombin contributes to lung inflammatory response. In this study, we developed a new mouse model that permits investigation of lung inflammation associated with intravascular coagulation. Using this mouse model and in vitro approaches, we addressed the role of non-muscle myosin light chain kinase (nmMLCK) in thrombin-induced endothelial cell (EC) inflammation and lung neutrophil (PMN) infiltration. Our in vitro experiments revealed a key role of nmMLCK in ICAM-1 expression by its ability to control nuclear translocation and transcriptional capacity of RelA/p65 in EC. When subjected to intraperitoneal thrombin challenge, wild type mice showed a marked increase in lung PMN infiltration via expression of ICAM-1. However, these responses were markedly attenuated in mice deficient in nmMLCK. These results provide mechanistic insight into lung inflammatory response associated with intravascular coagulation and identify nmMLCK as a critical target for modulation of lung inflammation.

Tools for experimental characterization of the non-uniform rotational distortion in intravascular OCT probes

NASA Astrophysics Data System (ADS)

Dufour, Marc L.; Bisaillon, Charles-Etienne; Lamouche, Guy; Vergnole, Sebastien; Hewko, Mark; D'Amours, Frédéric; Padioleau, Christian; Sowa, Michael

2011-03-01

The Industrial Material Institute (IMI) together with the Institute for Biodiagnostic (IBD) has developed its own optical catheters for cardiovascular imaging applications. Those catheters have been used experimentally in the in vitro coronary artery model of the Langendorff beating heart and in a percutaneous coronary intervention procedure in a porcine model. For some catheter designs, non-uniform rotational distortion (NURD) can be observed as expected from past experience with intra-vascular ultrasound (IVUS) catheters. A two-dimensional (2D) coronary artery test bench that simulates the path into the coronary arteries has been developed. The presence or absence of NURD can be assessed with the test bench using a custom-built cardiovascular Optical Coherence Tomography (OCT) imaging system. A square geometry instead of the circular shape of an artery is used to simulate the coronary arteries. Thereby, it is easier to visualize NURD when it is present. The accumulated torsion induced by the friction on the catheter is measured along the artery path. NURD is induced by the varying friction force that is balanced by the accumulated torsion force. The pullback force is measured and correlated with NURD observed in the 2D test bench. Finally, a model is presented to help understanding the mechanical constraint that leads to the friction force variations.

Plasmin Inhibitors Prevent Leukocyte Accumulation and Remodeling Events in the Postischemic Microvasculature

PubMed Central

Reichel, Christoph A.; Lerchenberger, Max; Uhl, Bernd; Rehberg, Markus; Berberich, Nina; Zahler, Stefan; Wymann, Matthias P.; Krombach, Fritz

2011-01-01

Clinical trials revealed beneficial effects of the broad-spectrum serine protease inhibitor aprotinin on the prevention of ischemia-reperfusion (I/R) injury. The underlying mechanisms remained largely unclear. Using in vivo microscopy on the cremaster muscle of male C57BL/6 mice, aprotinin as well as inhibitors of the serine protease plasmin including tranexamic acid and ε-aminocaproic acid were found to significantly diminish I/R-elicited intravascular firm adherence and (subsequent) transmigration of neutrophils. Remodeling of collagen IV within the postischemic perivenular basement membrane was almost completely abrogated in animals treated with plasmin inhibitors or aprotinin. In separate experiments, incubation with plasmin did not directly activate neutrophils. Extravascular, but not intravascular administration of plasmin caused a dose-dependent increase in numbers of firmly adherent and transmigrated neutrophils. Blockade of mast cell activation as well as inhibition of leukotriene synthesis or antagonism of the platelet-activating-factor receptor significantly reduced plasmin-dependent neutrophil responses. In conclusion, our data suggest that extravasated plasmin(ogen) mediates neutrophil recruitment in vivo via activation of perivascular mast cells and secondary generation of lipid mediators. Aprotinin as well as the plasmin inhibitors tranexamic acid and ε-aminocaproic acid interfere with this inflammatory cascade and effectively prevent postischemic neutrophil responses as well as remodeling events within the vessel wall. PMID:21364954

Critical Role of Non-Muscle Myosin Light Chain Kinase in Thrombin-Induced Endothelial Cell Inflammation and Lung PMN Infiltration

PubMed Central

Fazal, Fabeha; Bijli, Kaiser M.; Murrill, Matthew; Leonard, Antony; Minhajuddin, Mohammad; Anwar, Khandaker N.; Finkelstein, Jacob N.; Watterson, D. Martin; Rahman, Arshad

2013-01-01

The pathogenesis of acute lung injury (ALI) involves bidirectional cooperation and close interaction between inflammatory and coagulation pathways. A key molecule linking coagulation and inflammation is the procoagulant thrombin, a serine protease whose concentration is elevated in plasma and lavage fluids of patients with ALI and acute respiratory distress syndrome (ARDS). However, little is known about the mechanism by which thrombin contributes to lung inflammatory response. In this study, we developed a new mouse model that permits investigation of lung inflammation associated with intravascular coagulation. Using this mouse model and in vitro approaches, we addressed the role of non-muscle myosin light chain kinase (nmMLCK) in thrombin-induced endothelial cell (EC) inflammation and lung neutrophil (PMN) infiltration. Our in vitro experiments revealed a key role of nmMLCK in ICAM-1 expression by its ability to control nuclear translocation and transcriptional capacity of RelA/p65 in EC. When subjected to intraperitoneal thrombin challenge, wild type mice showed a marked increase in lung PMN infiltration via expression of ICAM-1. However, these responses were markedly attenuated in mice deficient in nmMLCK. These results provide mechanistic insight into lung inflammatory response associated with intravascular coagulation and identify nmMLCK as a critical target for modulation of lung inflammation. PMID:23555849

[Study on surface modification and biocompatibility of NiTi alloy intravascular stents].

PubMed

Shen, Yang; Wang, Gui-xue; Quan, Xue-jun; Yu, Qing-song

2006-01-01

This paper introduces the surface modification of NiTi alloy intravascular stents for roughness by chemical erosion and plasma deposition technology. The stent which had been granulated with chemical erosion was treated with TiO2 film prepared with Gel-sol. The study on the biocompatibility of the modified stent by the above two ways shows that the modified stent is rougher, and its anticoagulation and hydrophilicity are improved. However, the capability of erosion resistance is not enhanced significantly.

The Diagnosis of Spontaneous Coronary Artery Dissection by Optical Coherence Tomography.

PubMed

Kanda, Takahiro; Tawarahara, Kei; Matsukura, Gaku; Matsunari, Masayoshi; Takabayashi, Rumi; Tamura, Jun; Ozeki, Mariko; Ukigai, Hiroshi

2018-02-15

Spontaneous coronary artery dissection (SCAD) is rare, but it frequently presents as acute myocardial infarction. It is frequently fatal and most cases are diagnosed at autopsy. We herein present the case of a 65-year-old woman with ST-elevation and myocardial infarction due to SCAD. Optical coherence tomography (OCT) helped us to confirm the diagnosis. The information on the intravascular morphology provided by OCT imaging is much more detailed in comparison to that provided by coronary angiography (CAG) and intravascular ultrasound (IVUS).

Successful removal of embolized chemoport catheter within the heart and pericardium: 3 case reports

PubMed Central

Yoon, Shin-Eui

2017-01-01

Central venous access devices are routinely used in patients with cancer. Although rare, catheter transaction with subsequent embolization is one of the major complications of intra-vascular devices. We describe two patients with embolized chemoport catheters within the heart that were successfully removed percutaneously using a goose-neck snare technique. We also describe a third patient with a fractured intra-vascular catheter in the pericardium removed by pericardiotomy, which can be the first case of the kind. PMID:28932593

Display Considerations For Intravascular Ultrasonic Imaging

NASA Astrophysics Data System (ADS)

Gessert, James M.; Krinke, Charlie; Mallery, John A.; Zalesky, Paul J.

1989-08-01

A display has been developed for intravascular ultrasonic imaging. Design of this display has a primary goal of providing guidance information for therapeutic interventions such as balloons, lasers, and atherectomy devices. Design considerations include catheter configuration, anatomy, acoustic properties of normal and diseased tissue, catheterization laboratory and operating room environment, acoustic and electrical safety, acoustic data sampling issues, and logistical support such as image measurement, storage and retrieval. Intravascular imaging is in an early stage of development so design flexibility and expandability are very important. The display which has been developed is capable of acquisition and display of grey scale images at rates varying from static B-scans to 30 frames per second. It stores images in a 640 X 480 X 8 bit format and is capable of black and white as well as color display in multiplevideo formats. The design is based on the industry standard PC-AT architecture and consists of two AT style circuit cards, one for high speed sampling and the other for scan conversion, graphics and video generation.

Systemic reactive angioendotheliomatosis-like syndrome in a steer presumed to be persistently infected with bovine viral diarrhea virus.

PubMed

Breshears, M A; Johnson, B J

2008-09-01

Unusual proliferative intravascular lesions were seen in multiple organs of a 2-year-old Corriente steer presumed to be persistently infected with bovine viral diarrhea virus (BVDV), based on widespread immunohistochemical detection of BVDV antigen. Proliferations of spindle cells, which were immunohistochemically positive for von Willebrand factor-related antigen, partially-to-completely occluded vessel lumens and were supported by cells that were immunohistochemically positive for smooth muscle actin. Distribution and character of the intraluminal proliferations are strikingly similar to those described in feline systemic reactive angioendotheliomatosis, a rare entity of unknown cause. The presence of occasional intravascular thrombi suggests that the proliferative vasculopathy was associated with an underlying thrombotic process with immunohistochemical similarities to thrombotic thrombocytopenic purpura of humans. Death of the steer was due to hemorrhage from a castration wound, which may indicate thrombocytopenia or platelet dysfunction. The role of persistent BVDV infection in the formation of the intravascular lesions is unknown.

Intravascular ultrasound in coronary atherosclerosis: a new approach to clinical assessment.

PubMed

Liebson, P R; Klein, L W

1992-06-01

Intravascular ultrasound evaluation of the coronary arteries by means of a selective coronary catheter attached to an ultrasound unit has afforded precise depiction of coronary lumen diameter and area at the level of the catheter tip. The arterial wall at this level can be evaluated for lipid, fibrous tissue, calcification, wall dissections, and intraluminal thrombi. The technique has the advantage over coronary angioscopy and angiography in that it does not require infusions or injections to allow visualization, and it has the ability to depict the inside of the arterial wall. The current disadvantages include the inability to visualize the vessel segments distal to the catheter tip. Three-dimensional reconstruction techniques allow depiction of the segment of the artery traversed by the catheter tip. The use of Doppler ultrasound imaging provides information on coronary flow velocities through coronary obstructions. Intravascular ultrasound images may provide information that complements the coronary arteriogram and may have an impact on patient care and clinical investigation strategies.

Evaluation of two different epidural catheters in clinical practice. narrowing down the incidence of paresthesia!

PubMed

Bouman, E A C; Gramke, H F; Wetzel, N; Vanderbroeck, T H T; Bruinsma, R; Theunissen, M; Kerkkamp, H E M; Marcus, M A E

2007-01-01

Although epidural anesthesia is considered safe, several complications may occur during puncture and insertion of a catheter. Incidences of paresthesia vary between 0.2 and 56%. A prospective, open, cohort-controlled pilot study was conducted in 188 patients, ASA I-III, age 19-87 years, scheduled for elective surgery and epidural anesthesia. We evaluated a 20 G polyamide (standard) catheter and a 20 G combined polyurethane-polyamide (new) catheter. Spontaneous reactions upon catheter-insertion, paresthesia on questioning, inadvertent dural or intravascular puncture, and reasons for early catheter removal were recorded. The incidence of paresthesia reported spontaneously was 21.3% with the standard catheter and 16.7% with the new catheter. Systematically asking for paresthesia almost doubled the paraesthesia rate. Intravascular cannulation occurred in 5%. No accidental dural punctures occurred. An overall incidence of 13.3% of technical problems led to early catheter removal. The new catheter was at least equivalent to the standard regarding epidural success rate and safety : rate of paresthesia, intravascular and dural cannulation.

Contrast-enhanced intravascular ultrasound pulse sequences for bandwidth-limited transducers.

PubMed

Maresca, David; Renaud, Guillaume; van Soest, Gijs; Li, Xiang; Zhou, Qifa; Shung, K Kirk; de Jong, Nico; van der Steen, Antonius F W

2013-04-01

We demonstrate two methods for vasa vasorum imaging using contrast-enhanced intravascular ultrasound, which can be performed using commercial catheters. Plaque neovascularization was recognized as an independent marker of coronary artery plaque vulnerability. IVUS-based methods to image the microvessels available to date require high bandwidth (-6 dB relative frequency bandwidth >70%), which are not routinely available commercially. We explored the potential of ultraharmonic imaging and chirp reversal imaging for vasa vasorum imaging. In vitro recordings were performed on a tissue-mimicking phantom using a commercial ultrasound contrast agent and a transducer with a center frequency of 34 MHz and a -6 dB relative bandwidth of 56%. Acoustic peak pressures <500 kPa were used. A tissue-mimicking phantom with channels down to 200 μm in diameter was successfully imaged by the two contrast detection sequences while the smallest channel stayed invisible in conventional intravascular ultrasound images. Ultraharmonic imaging provided the best contrast agent detection. Copyright © 2013 World Federation for Ultrasound in Medicine & Biology. All rights reserved.

Clinical Neuropathology practice guide 3-2014: combined nerve and muscle biopsy in the diagnostic workup of neuropathy - the Bordeaux experience.

PubMed

Vital, Anne; Vital, Claude

2014-01-01

Simultaneous combined superficial peroneal nerve and peroneous brevis muscle biopsy, via the same cutaneous incision, allows examination of several tissue specimens and significantly improves the diagnosis of systemic diseases with peripheral nerve involvement. Vasculitides are certainly the most frequently diagnosed on neuro-muscular biopsies, but this procedure is also well advised to asses a diagnosis of sarcoidosis or amyloidosis. More occasionally, combined nerve and muscle biopsy may reveal an unpredicted diagnosis of cholesterol embolism, intra-vascular lymphoma, or enables complementary diagnosis investigations on mitochondrial cytopathy or storage disease.

Intrapartum anti-disseminated intravascular coagulation therapy leading to successful vaginal delivery following intrauterine fetal death caused by placental abruption: a case report.

PubMed

Honda, Michiko; Matsunaga, Shigetaka; Era, Sumiko; Takai, Yasushi; Baba, Kazunori; Seki, Hiroyuki

2014-12-23

Disseminated intravascular coagulation due to placental abruption with intrauterine fetal death is not uncommon. It can result in increased maternal mortality rates and the need for hysterectomy or greater transfusion volumes if the delivery is not completed within six to eight hours. However, consensus is lacking regarding the delivery approach for cases in which delivery is prolonged. A 37-year-old Japanese woman was transported to our tertiary center two and a half hours after the onset of labor because of a diagnosis of placental abruption with intrauterine fetal death at 40 weeks and three days' gestation. On arrival, although severe hypofibrinogenemia was observed, there was no external hemorrhage. Because her cervical canal dilation was good (Bishop score, 7), labor was induced using oxytocin. Anti-disseminated intravascular coagulation therapy was simultaneously started via transfusion. After her hypofibrinogenemia resolved, delivery progressed rapidly, and the fetus was delivered approximately 10 hours after the onset. To reduce postpartum hemorrhage, 6g of fibrinogen concentrate and tranexamic acid, an antifibrinolytic agent, were administered immediately before extraction of the dead fetus and placenta. Although the amount of intrapartum hemorrhage was 1824g, there was no abnormal bleeding after delivery, and our patient was discharged three days later. In cases of placental abruption complicated with disseminated intravascular coagulation, intrapartum administration of coagulation factors can simultaneously promote effective labor and correct hypofibrinogenemia, enabling minimally invasive vaginal delivery.

Cardiovascular Optical Coherence Tomography

NASA Astrophysics Data System (ADS)

Yonetsu, Taishi; Villiger, Martin; Bouma, Brett E.; Jang, Ik-Kyung

The potential of optical coherence tomography (OCT) for intravascular imaging and assessing the microstructure of atherosclerosis was suggested already by Huang et al. at the very beginning of OCT [1]. For ophthalmology, the eye provides a natural window for OCT to image the retinal microstructure, and OCT has rapidly become the standard imaging modality to diagnose retinal disease and assess disease progression and response to therapy [1, 2]. Intravascular imaging is more invasive by nature and requires imaging through a catheter probe. This has triggered the development of advanced fiber-optic OCT systems with compact, rotating fiber probes, to image the vessel by circumferentially scanning the luminal wall [3, 4]. In 1998, we established the first cardiac OCT research group at the Massachusetts General Hospital to explore the clinical applications of OCT. The first imaging of rabbit aorta was reported by Fujimoto et al. [5], followed by the first swine measurements in vivo by Tearney et al. [6], and finally the first assessment of coronary arteries in patients by Jang et al. [7]. The scope of this chapter is to highlight the steps taken to bring intravascular OCT from bench to bedside over the last 15 years. We will give a general description of atherosclerosis and its pathophysiology and the specific technical implementation of OCT for intravascular imaging through a fiber-optic probe. The motivation is to provide sufficient medical details to provide a basic introduction to the terminology, principles, and challenges of intracoronary imaging.

THE EFFECT OF PULMONARY CONGESTION ON THE ON THE VENTILATION OF THE LUNGS

PubMed Central

Drinker, Cecil K.; Peabody, Francis W.; Blumgart, Herrmann L.

1922-01-01

1. A method is described for producing pulmonary congestion, together with what may be termed a differential spirometer method for studying lung ventilation. 2. The method utilized permits an approximately accurate prediction of degrees of pulmonary edema in the living animal, and suggests avenues of approach for the very difficult problems of pulmonary capillary pressure. 3. It is shown that intravascular blood can encroach markedly upon the pulmonary air space. Although the methods used in these animal experiments do not resemble vital capacity measurements in man, their result is so definite that their applicability to clinical conditions may be considered. 4. The similarity between the experiments described and certain conditions of cardiac decompensation, of which mitral stenosis is the best example, is pointed out. PMID:19868589

Daptomycin in the Clinical Setting: 8-Year Experience with Gram-positive Bacterial Infections from the EU-CORE(SM) Registry.

PubMed

Gonzalez-Ruiz, Armando; Gargalianos-Kakolyris, Panayiotis; Timerman, Artur; Sarma, Jayanta; José González Ramallo, Víctor; Bouylout, Kamel; Trostmann, Uwe; Pathan, Rashidkhan; Hamed, Kamal

2015-06-01

The aim of this study was to evaluate the clinical outcomes and safety of daptomycin therapy in patients with serious Gram-positive infections. Patients were enrolled in the European Cubicin(®) Outcomes Registry and Experience (EU-CORE(SM)), a non-interventional, multicenter, observational registry. The real-world data were collected across 18 countries (Europe, Latin America, and Asia) for patients who had received at least one dose of daptomycin between January 2006 and April 2012. Two-year follow-up data were collected until 2014 for patients with endocarditis, intracardiac/intravascular device infection, osteomyelitis, or orthopedic device infection. A total of 6075 patients were enrolled. The most common primary infections were complicated skin and soft tissue infection (31.7%) and bacteremia (20.7%). Staphylococcus aureus was the most frequently reported pathogen (42.9%; methicillin-resistant S. aureus [MRSA], 23.2%), followed by Staphylococcus epidermidis and other coagulase-negative staphylococci (CoNS, 28.5%). The most commonly prescribed dose of daptomycin was 6 mg/kg/day (43.6%), and the median duration of therapy was 11 (range 1-300) days. Overall clinical success rate was 80.5%, and was similar whether daptomycin was used as first-line (82.9%) or second-line (79.2%) therapy. Clinical success rates were high in patients with S. aureus (83.9%; MRSA 83.0%) and CoNS (including S. epidermidis, 82.5%) infections. The majority of patients with endocarditis or intracardiac/intravascular device infection (86.7%) or osteomyelitis/orthopedic device infection (85.9%) had a sustained response during the 2-year follow-up period. There were no new or unexpected safety findings. Results from real-world clinical experience showed that daptomycin is a valuable therapeutic option in the management of various difficult-to-treat Gram-positive infections. This study was funded by Novartis Pharma AG.

Intravascular Raman spectroscopic catheter for molecular diagnosis of atherosclerotic coronary disease

NASA Astrophysics Data System (ADS)

Komachi, Yuichi; Sato, Hidetoshi; Tashiro, Hideo

2006-10-01

An intravascular catheter for Raman spectroscopic detection and analysis of coronary atherosclerotic disease has been developed. The catheter, having an outer diameter of 2 mm, consisted of a side-view-type micro-Raman probe, an imaging fiber bundle, a working channel (injection drain), and a balloon. By inflating the balloon, the probe was brought close to the inner wall of a modeled blood flow system and detected a phantom target buried in the wall. Results obtained demonstrate the possibility of using the spectroscopic catheter for molecular diagnosis of coronary lesions.

[Intravascular Hemolysis Caused by Stenosis of an Elephant Trunk;Report of a Case].

PubMed

Takamaru, Rikako; Kawahito, Koji; Aizawa, Kei; Misawa, Yoshio

2017-07-01

Symptomatic intravascular hemolysis after prosthetic aortic graft replacement is rare. It is primarily attributed to mechanical injury of red blood cells caused by stenosis of the vascular graft. A 50-year-old man presented with hemolytic anemia, 5 years after total arch replacement with an elephant trunk for type A aortic dissection. The hemolysis was caused by graft stenosis of the elephant trunk. Endovascular treatment for the stenotic elephant trunk was successfully performed. The postoperative course was uneventful, and the hemolysis was resolved immediately after operation.

Removal of Chronic Intravascular Blood Clots using Liquid Plasma

NASA Astrophysics Data System (ADS)

Jung, Jae-Chul; Choi, Myeong; Koo, Il; Yu, Zengqi; Collins, George

2011-10-01

An electrical embolectomy device for removing chronic intravascular blood clots using liquid plasma under saline environment was demonstrated. We employed a proxy experimental blood clot model of deep vein thrombosis (DVT) and actual equine blood clot. Thermal damage to contiguous tissue and the collagen denaturing via the plasma irradiation were investigated by histological analysis using birefringence of the tissue and verified by FT-IR spectroscopic study, respectively, which showed the high removal rate up to 2 mm per minute at room temperature and small thermal damage less than 200 μm.

Novel intravascular ultrasound-guided method to create transintimal arterial communications: initial experience in peripheral occlusive disease and aortic dissection.

PubMed

Saket, Ramin R; Razavi, Mahmood K; Padidar, Arash; Kee, Stephen T; Sze, Daniel Y; Dake, Michael D

2004-06-01

To report our experience using a commercially available catheter-based system equipped with an intravascular ultrasound (IVUS) transducer to achieve controlled true lumen re-entry in patients undergoing subintimal angioplasty for chronic total occlusions (CTO) or aortic dissections. During an 8-month period, 10 patients (6 men; mean age 73.4 years) with lower extremity (LE) ischemia from CTOs (n=7) or true lumen collapse from aortic dissections (n=3) were treated. Subintimal access and controlled re-entry of the CTOs were performed with a commercially available 6.2-F dual-lumen catheter, which contained an integrated 64-element phased-array IVUS transducer and a deployable 24-G needle through which a guidewire was passed once the target lumen was reached. The occluded segments were balloon dilated; self-expanding nitinol stents were deployed. In the aortic dissections, fenestrations were performed using the same device, with the IVUS unit acting as the guide. The fenestrations were balloon dilated and stented to support the true lumen. Time to effective re-entry ranged from 6 to 10 minutes (mean 7) in the CTOs; antegrade flow was restored in all 7 CTOs, and the patients were free of ischemic symptoms at up to 8-month follow-up. In the aortic dissection cases, the fenestrations equalized pressures between the lumens and restored flow into the compromised vessels. There were no complications related to the use of this device in any of the 10 patients. Our preliminary results demonstrate the feasibility of using this catheter-based system for subintimal recanalization with controlled re-entry in CTOs and for aortic flap fenestrations in aortic dissections. This approach can improve the technical success rate, reduce the time of the procedure, and minimize potential complications.

[Endovascular surgery in the war].

PubMed

Reva, V A; Samokhvalov, I M

2015-01-01

Rapid growth of medical technologies has led to implementation of endovascular methods of diagnosis and treatment into rapidly developing battlefield surgery. This work based on analysing all available current publications generalizes the data on using endovascular surgery in combat vascular injury. During the Korean war (1950-1953) American surgeons for the first time performed endovascular balloon occlusion of the aorta - the first intravascular intervention carried out in a zone of combat operations. Half a century thereafter, with the beginning of the war in Afghanistan (2001) and in Iraq (2003) surgeons of central hospitals of the USA Armed Forces began performing delayed endovascular operations to the wounded. The development of technologies, advent of mobile angiographs made it possible to later on implement high-tech endovascular interventions in a zone of combat operations. At first, more often they performed implantation of cava filters, somewhat afterward - angioembolization of damaged accessory vessels, stenting and endovascular repair of major arteries. The first in the theatre of war endovascular prosthetic repair of the thoracic aorta for severe closed injury was performed in 2008. Russian experience of using endovascular surgery in combat injuries is limited to diagnostic angiography and regional intraarterial perfusion. Despite the advent of stationary angiographs in large hospitals of the RF Ministry of Defence in the early 1990s, endovascular operations for combat vascular injury are casuistic. Foreign experience in active implementation of endovascular technologies to treatment of war-time injuries has substantiated feasibility of using intravascular interventions in tertiary care military hospitals. Carrying out basic training courses on endovascular surgery should become an organic part of preparing multimodality general battlefield surgeons rendering care on the theatre of combat operations.

Whole plant based treatment of hypercholesterolemia with Crataegus laevigata in a zebrafish model.

PubMed

Littleton, Robert M; Miller, Matthew; Hove, Jay R

2012-07-23

Consumers are increasingly turning to plant-based complementary and alternative medicines to treat hypercholesterolemia. Many of these treatments are untested and their efficacy is unknown. This multitude of potential remedies necessitates a model system amenable to testing large numbers of organisms that maintains similarity to humans in both mode of drug administration and overall physiology. Here we develop the larval zebrafish (4-30 days post fertilization) as a vertebrate model of dietary plant-based treatment of hypercholesterolemia and test the effects of Crataegus laevigata in this model. Larval zebrafish were fed high cholesterol diets infused with fluorescent sterols and phytomedicines. Plants were ground with mortar and pestle into a fine powder before addition to food. Fluorescent sterols were utilized to optically quantify relative difference in intravascular cholesterol levels between groups of fish. We utilized the Zeiss 7-Live Duo high-speed confocal platform in order to both quantify intravascular sterol fluorescence and to capture video of the heart beat for determination of cardiac output. In this investigation we developed and utilized a larval zebrafish model to investigate dietary plant-based intervention of the pathophysiology of hypercholesterolemia. We found BODIPY-cholesterol effectively labels diet-introduced intravascular cholesterol levels (P < 0.05, Student's t-test). We also established that zebrafish cardiac output declines as cholesterol dose increases (difference between 0.1% and 8% (w/w) high cholesterol diet-treated cardiac output significant at P < 0.05, 1-way ANOVA). Using this model, we found hawthorn leaves and flowers significantly reduce intravascular cholesterol levels (P < 0.05, 1-way ANOVA) and interact with cholesterol to impact cardiac output in hypercholesterolemic fish (2-way ANOVA, P < 0.05 for interaction effect). The results of this study demonstrate that the larval zebrafish has the potential to become a powerful model to test plant based dietary intervention of hypercholesterolemia. Using this model we have shown that hawthorn leaves and flowers have the potential to affect cardiac output as well as intravascular cholesterol levels. Further, our observation that hawthorn leaves and flowers interact with cholesterol to impact cardiac output indicates that the physiological effects of hawthorn may depend on diet.

Inhibition of acid-induced lung injury by hyperosmolar sucrose in rats.

PubMed

Safdar, Zeenat; Yiming, Maimiti; Grunig, Gabriele; Bhattacharya, Jahar

2005-10-15

Acid aspiration causes acute lung injury (ALI). Recently, we showed that a brief intravascular infusion of hyperosmolar sucrose, given concurrently with airway acid instillation, effectively blocks the ensuing ALI. The objective of the present study was to determine the extent to which intravascular infusion of hyperosmolar sucrose might protect against acid-induced ALI when given either before or after acid instillation. Our studies were conducted in anesthetized rats and in isolated, blood-perfused rat lungs. We instilled HCl through the airway, and we quantified lung injury in terms of the extravascular lung water (EVLW) content, filtration coefficient (Kfc), and cell counts and protein concentration in the bronchoalveolar lavage. We infused hyperosmolar sucrose via the femoral vein. In anesthetized rats, airway HCl instillation induced ALI as indicated by a 52% increase of EVLW and a threefold increase in Kfc. However, a 15-min intravenous infusion of hyperosmolar sucrose given up to 1 h before or 30 min after acid instillation markedly blunted the increases in EVLW, as well as the increases in cell count, and in protein concentration in the bronchoalveolar lavage. Hyperosmolar pretreatment also blocked the acid-induced increase of Kfc. Studies in isolated perfused lungs indicated that the protective effect of hyperosmolar sucrose was leukocyte independent. We conclude that a brief period of vascular hyperosmolarity protects against acid-induced ALI when the infusion is administered shortly before, or shortly after, acid instillation in the airway. The potential applicability of hyperosmolar sucrose in therapy for ALI requires consideration.

On the suppression of plasma nonesterified fatty acids by insulin during enhanced intravascular lipolysis in humans.

PubMed

Carpentier, André C; Frisch, Frédérique; Cyr, Denis; Généreux, Philippe; Patterson, Bruce W; Giguère, Robert; Baillargeon, Jean-Patrice

2005-11-01

During the fasting state, insulin reduces nonesterified fatty acid (NEFA) appearance in the systemic circulation mostly by suppressing intracellular lipolysis in the adipose tissue. In the postprandial state, insulin may also control NEFA appearance through enhanced trapping into the adipose tissue of NEFA derived from intravascular triglyceride lipolysis. To determine the contribution of suppression of intracellular lipolysis in the modulation of plasma NEFA metabolism by insulin during enhanced intravascular triglyceride lipolysis, 10 healthy nonobese subjects underwent pancreatic clamps at fasting vs. high physiological insulin level with intravenous infusion of heparin plus Intralipid. Nicotinic acid was administered orally during the last 2 h of each 4-h clamp to inhibit intracellular lipolysis and assess insulin's effect on plasma NEFA metabolism independently of its effect on intracellular lipolysis. Stable isotope tracers of palmitate, acetate, and glycerol were used to assess plasma NEFA metabolism and total triglyceride lipolysis in each participant. The glycerol appearance rate was similar during fasting vs. high insulin level, but plasma NEFA levels were significantly lowered by insulin. Nicotinic acid significantly blunted the insulin-mediated suppression of plasma palmitate appearance and oxidation rates by approximately 60 and approximately 70%, respectively. In contrast, nicotinic acid did not affect the marked stimulation of palmitate clearance by insulin. Thus most of the insulin-mediated reduction of plasma NEFA appearance and oxidation can be explained by suppression of intracellular lipolysis during enhanced intravascular triglyceride lipolysis in healthy humans. Our results also suggest that insulin may affect plasma NEFA clearance independently of the suppression of intracellular lipolysis.

Implantable intravascular defibrillator: defibrillation thresholds of an intravascular cardioverter-defibrillator compared with those of a conventional ICD in humans.

PubMed

Neuzil, Petr; Reddy, Vivek Y; Merkely, Bela; Geller, Laszlo; Molnar, Levente; Bednarek, Jacek; Bartus, Krzysztof; Richey, Mark; Bsee, T J Ransbury; Sanders, William E

2014-02-01

A percutaneous intravascular cardioverter-defibrillator (PICD) has been developed with a right ventricular (RV) single-coil lead and titanium electrodes in the superior vena cava (SVC)-brachiocephalic vein (BCV) region and the inferior vena cava (IVC). To compare defibrillation thresholds (DFTs) of the PICD with those of a conventional ICD in humans. Ten patients with ischemic cardiomyopathy and ejection fraction ≤35% were randomized to initial testing with either PICD or conventional ICD. A standard dual-coil lead was positioned in the RV apex. If randomized to PICD, the device was placed into the vasculature such that 1 titanium electrode was positioned in the SVC-BCV region and the second in the IVC. For PICD DFTs, the RV coil of the conventional ICD lead was connected to the PICD mandrel [shock vector: RV (+) to SVC-BCV (-) + IVC (-)]. When testing the conventional ICD, a subcutaneous pocket was formed in the left pectoralis region and the ICD was connected to the lead system and positioned in the pocket [shock vector: RV (+) to SVC (-) + active can (-)]. Each device was removed before testing with the other. A step-down binary search protocol determined the DFT, with the initial shock being 9 J. The mean PICD DFT was 7.6 ± 3.3 J, and the conventional ICD system demonstrated a mean DFT of 9.5 ± 4.7 J (N = 10; paired t test, P = .28). The intravascular defibrillator has DFTs similar to those of commercially available ICDs. Published by Heart Rhythm Society on behalf of Heart Rhythm Society.

An Integrated System for Superharmonic Contrast-Enhanced Ultrasound Imaging: Design and Intravascular Phantom Imaging Study.

PubMed

Li, Yang; Ma, Jianguo; Martin, K Heath; Yu, Mingyue; Ma, Teng; Dayton, Paul A; Jiang, Xiaoning; Shung, K Kirk; Zhou, Qifa

2016-09-01

Superharmonic contrast-enhanced ultrasound imaging, also called acoustic angiography, has previously been used for the imaging of microvasculature. This approach excites microbubble contrast agents near their resonance frequency and receives echoes at nonoverlapping superharmonic bandwidths. No integrated system currently exists could fully support this application. To fulfill this need, an integrated dual-channel transmit/receive system for superharmonic imaging was designed, built, and characterized experimentally. The system was uniquely designed for superharmonic imaging and high-resolution B-mode imaging. A complete ultrasound system including a pulse generator, a data acquisition unit, and a signal processing unit were integrated into a single package. The system was controlled by a field-programmable gate array, on which multiple user-defined modes were implemented. A 6-, 35-MHz dual-frequency dual-element intravascular ultrasound transducer was designed and used for imaging. The system successfully obtained high-resolution B-mode images of coronary artery ex vivo with 45-dB dynamic range. The system was capable of acquiring in vitro superharmonic images of a vasa vasorum mimicking phantom with 30-dB contrast. It could detect a contrast agent filled tissue mimicking tube of 200 μm diameter. For the first time, high-resolution B-mode images and superharmonic images were obtained in an intravascular phantom, made possible by the dedicated integrated system proposed. The system greatly reduced the cost and complexity of the superharmonic imaging intended for preclinical study. Significant: The system showed promise for high-contrast intravascular microvascular imaging, which may have significant importance in assessment of the vasa vasorum associated with atherosclerotic plaques.

Polymer coating embolism from intravascular medical devices - a clinical literature review.

PubMed

Chopra, Amitabh M; Mehta, Monik; Bismuth, Jean; Shapiro, Maksim; Fishbein, Michael C; Bridges, Alina G; Vinters, Harry V

Over the past three decades, lubricious (hydrophobic and/or hydrophilic) polymer-coated devices have been increasingly adopted by interventional physicians and vascular surgeons to access and treat a wider range of clinical presentations. Recent clinical literature highlights the presence of polymer coating emboli within the anatomy - a result of coating separation from an intravascular device - and associates it with a range of adverse clinical sequelae. The 2015 U.S. Food and Drug Administration safety communication titled "Lubricious Coating Separation from Intravascular Medical Devices" acknowledges these concerns and concludes that it will work with stakeholders to develop nonclinical test methodologies, establish performance criteria, and identify gaps in current national and international device standards for coating integrity performance. Despite this communication and multiple case reports from interventional physicians, pathologists, dermatologists and other involved physician specialties, polymer coating embolism remains clinically underrecognized. This article consolidates the available literature on polymer coating embolism (1986-2016) and highlights the following relevant information for the physician: (a) the history and elusive nature of polymer coating embolism; (b) potential incidence rates of this phenomenon; (c) reported histologic findings and clinical effects of polymer emboli in the anatomy; (d) the importance of the collaborative clinician-pathologist partnership to report polymer embolism findings; and (e) the importance to study particulate release from intravascular devices so as to further understand and potentially evolve coated interventional technologies. Preliminary research on coatings highlights the potential of using iterations of coatings on medical devices that attain the desired therapeutic result and mitigate or eliminate particulates altogether. Copyright © 2017 The Authors. Published by Elsevier Inc. All rights reserved.

Multi-Frequency Intravascular Ultrasound (IVUS) Imaging

PubMed Central

Ma, Teng; Yu, Mingyue; Chen, Zeyu; Fei, Chunlong; Shung, K. Kirk; Zhou, Qifa

2015-01-01

Acute coronary syndrome (ACS) is frequently associated with the sudden rupture of a vulnerable atherosclerotic plaque within the coronary artery. Several unique physiological features, including a thin fibrous cap accompanied by a necrotic lipid core, are the targeted indicators for identifying the vulnerable plaques. Intravascular ultrasound (IVUS), a catheter-based imaging technology, has been routinely performed in clinics for more than 20 years to describe the morphology of the coronary artery and guide percutaneous coronary interventions. However, conventional IVUS cannot facilitate the risk assessment of ACS because of its intrinsic limitations, such as insufficient resolution. Renovation of the IVUS technology is essentially needed to overcome the limitations and enhance the coronary artery characterization. In this paper, a multi-frequency intravascular ultrasound (IVUS) imaging system was developed by incorporating a higher frequency IVUS transducer (80 to 150 MHz) with the conventional IVUS (30–50 MHz) system. The newly developed system maintains the advantage of deeply penetrating imaging with the conventional IVUS, while offering an improved higher resolution image with IVUS at a higher frequency. The prototyped multi-frequency catheter has a clinically compatible size of 0.95 mm and a favorable capability of automated image co-registration. In vitro human coronary artery imaging has demonstrated the feasibility and superiority of the multi-frequency IVUS imaging system to deliver a more comprehensive visualization of the coronary artery. This ultrasonic-only intravascular imaging technique, based on a moderate refinement of the conventional IVUS system, is not only cost-effective from the perspective of manufacturing and clinical practice, but also holds the promise of future translation into clinical benefits. PMID:25585394

All-optical pulse-echo ultrasound probe for intravascular imaging (Conference Presentation)

NASA Astrophysics Data System (ADS)

Colchester, Richard J.; Noimark, Sacha; Mosse, Charles A.; Zhang, Edward Z.; Beard, Paul C.; Parkin, Ivan P.; Papakonstantinou, Ioannis; Desjardins, Adrien E.

2016-02-01

High frequency ultrasound probes such as intravascular ultrasound (IVUS) and intracardiac echocardiography (ICE) catheters can be invaluable for guiding minimally invasive medical procedures in cardiology such as coronary stent placement and ablation. With current-generation ultrasound probes, ultrasound is generated and received electrically. The complexities involved with fabricating these electrical probes can result in high costs that limit their clinical applicability. Additionally, it can be challenging to achieve wide transmission bandwidths and adequate wideband reception sensitivity with small piezoelectric elements. Optical methods for transmitting and receiving ultrasound are emerging as alternatives to their electrical counterparts. They offer several distinguishing advantages, including the potential to generate and detect the broadband ultrasound fields (tens of MHz) required for high resolution imaging. In this study, we developed a miniature, side-looking, pulse-echo ultrasound probe for intravascular imaging, with fibre-optic transmission and reception. The axial resolution was better than 70 microns, and the imaging depth in tissue was greater than 1 cm. Ultrasound transmission was performed by photoacoustic excitation of a carbon nanotube/polydimethylsiloxane composite material; ultrasound reception, with a fibre-optic Fabry-Perot cavity. Ex vivo tissue studies, which included healthy swine tissue and diseased human tissue, demonstrated the strong potential of this technique. To our knowledge, this is the first study to achieve an all-optical pulse-echo ultrasound probe for intravascular imaging. The potential for performing all-optical B-mode imaging (2D and 3D) with virtual arrays of transmit/receive elements, and hybrid imaging with pulse-echo ultrasound and photoacoustic sensing are discussed.

The extracranial venous system in the heads of beaked whales, with implications on diving physiology and pathogenesis.

PubMed

Costidis, Alexander M; Rommel, Sentiel A

2016-01-01

Beaked whales are a poorly known but diverse group of whales that have received considerable attention due to strandings that have been temporally and spatially associated with naval sonar deployment. Postmortem studies on stranded carcasses have revealed lesions consistent with decompression sickness, including intravascular gas and fat emboli. These findings have been supported by analyses of intravascular gas emboli showing composition dominated by nitrogen gas. To increase our understanding of the pathophysiology of nitrogen bubble formation and intravascular embolization, we examined the gross and microscopic anatomy of the venous system in the head of beaked whales. Since the potential sources of intravascular fat and gas emboli were of greatest interest, focus was placed on the acoustic fat bodies and pneumatic accessory sinus system. Herein, we describe intimate arteriovenous associations with specialized adipose depots and air sinuses in beaked whales. These vascular structures comprise an extensive network of thin-walled vessels with a large surface area, which is likely to facilitate exchange of nitrogen gas and may, therefore, form anatomic regions that may be important in physiological management of diving gases. These structures may also be vulnerable to pathologic introduction of emboli into the vascular system. Expansive, thin-walled venous lakes are found within the pterygoid region, which suggest the potential for nitrogen exchange as well as for compensation of middle-ear pressures during descent on a dive. These findings warrant further research into the structure and function of this morphology as it relates to normal and pathologic physiology. © 2015 Wiley Periodicals, Inc.

Pseudo-extravasation rate constant of dynamic susceptibility contrast-MRI determined from pharmacokinetic first principles.

PubMed

Li, Xin; Varallyay, Csanad G; Gahramanov, Seymur; Fu, Rongwei; Rooney, William D; Neuwelt, Edward A

2017-11-01

Dynamic susceptibility contrast-magnetic resonance imaging (DSC-MRI) is widely used to obtain informative perfusion imaging biomarkers, such as the relative cerebral blood volume (rCBV). The related post-processing software packages for DSC-MRI are available from major MRI instrument manufacturers and third-party vendors. One unique aspect of DSC-MRI with low-molecular-weight gadolinium (Gd)-based contrast reagent (CR) is that CR molecules leak into the interstitium space and therefore confound the DSC signal detected. Several approaches to correct this leakage effect have been proposed throughout the years. Amongst the most popular is the Boxerman-Schmainda-Weisskoff (BSW) K 2 leakage correction approach, in which the K 2 pseudo-first-order rate constant quantifies the leakage. In this work, we propose a new method for the BSW leakage correction approach. Based on the pharmacokinetic interpretation of the data, the commonly adopted R 2 * expression accounting for contributions from both intravascular and extravasating CR components is transformed using a method mathematically similar to Gjedde-Patlak linearization. Then, the leakage rate constant (K L ) can be determined as the slope of the linear portion of a plot of the transformed data. Using the DSC data of high-molecular-weight (~750 kDa), iron-based, intravascular Ferumoxytol (FeO), the pharmacokinetic interpretation of the new paradigm is empirically validated. The primary objective of this work is to empirically demonstrate that a linear portion often exists in the graph of the transformed data. This linear portion provides a clear definition of the Gd CR pseudo-leakage rate constant, which equals the slope derived from the linear segment. A secondary objective is to demonstrate that transformed points from the initial transient period during the CR wash-in often deviate from the linear trend of the linearized graph. The inclusion of these points will have a negative impact on the accuracy of the leakage rate constant, and even make it time dependent. Copyright © 2017 John Wiley & Sons, Ltd.

Detection and characterization of early plaque formations by Raman probe spectroscopy and optical coherence tomography: an in vivo study on a rabbit model

NASA Astrophysics Data System (ADS)

Matthäus, Christian; Dochow, Sebastian; Egodage, Kokila D.; Romeike, Bernd F.; Brehm, Bernhard R.; Popp, Jürgen

2018-01-01

Intravascular imaging techniques provide detailed specification about plaque appearance and morphology, but cannot deliver information about the biochemical composition of atherosclerotic plaques. As the biochemical composition is related to the plaque type, important aspects such as the risk of a plaque rupture and treatment are still difficult to assess. Currently, various spectroscopic techniques are tested for potential applications for the chemical analysis of plaque depositions. Here, we employ Raman spectroscopy in combination with optical coherence tomography (OCT) for the characterization of plaques on rabbits in vivo. Experiments were carried out on New Zealand white rabbits treated with a fat- and cholesterol-enriched diet, using a Raman probe setup with a 785-nm multimode laser as an excitation source. Subsequently, OCT images were acquired with a swept source at 1305±55 nm at 22.6 mW. Raman spectra were recorded from normal regions and regions with early plaque formations. The probe positioning was monitored by x-ray angiography. The spectral information identified plaque depositions consisting of lipids, with triglycerides as the major component. Afterward, OCT images of the spectroscopically investigated areas were obtained. The spectral information correlates well with the observed intravascular morphology and is in good agreement with histology. Raman spectroscopy can provide detailed biochemical specification of atherosclerotic plaques.

Reduction of resonant RF heating in intravascular catheters using coaxial chokes.

PubMed

Ladd, M E; Quick, H H

2000-04-01

The incorporation of RF coils into the tips of intravascular devices has been shown to enable the localization of catheters and guidewires under MR guidance. Furthermore, such coils can be used for endoluminal imaging. The long cable required to connect the coil with the scanner input inadvertently acts as a dipole antenna which picks up RF energy from the body coil during transmit. Currents are induced on the cable which can lead to localized heating of surrounding tissue. Cables of various lengths were measured to determine if a resonance in the heating as a function of cable length could be found. Coaxial chokes with a length of lambda/4 were added to coaxial cables to reduce the amplitude of the currents induced on the cable shield. A 0.7-mm diameter triaxial cable, small enough to fit into a standard intravascular device, was developed and measured both with and without a coaxial choke. It is demonstrated that resonant heating does occur and that it can be significantly reduced by avoiding a resonant length of cable and by including coaxial chokes on the cable.

NIR fluorescence lifetime sensing through a multimode fiber for intravascular molecular probing

NASA Astrophysics Data System (ADS)

Ingelberts, H.; Hernot, S.; Debie, P.; Lahoutte, T.; Kuijk, M.

2016-04-01

Coronary artery disease (CAD) contributes to millions of deaths each year. The identification of vulnerable plaques is essential to the diagnosis of CAD but is challenging. Molecular probes can improve the detection of these plaques using intravascular imaging methods. Fluorescence lifetime sensing is a safe and robust method to image these molecular probes. We present two variations of an optical system for intravascular near-infrared (NIR) fluorescence lifetime sensing through a multimode fiber. Both systems are built around a recently developed fast and efficient CMOS detector, the current-assisted photonic sampler (CAPS) that is optimized for sub-nanosecond NIR fluorescence lifetime sensing. One system mimics the optical setup of an epifluorescence microscope while the other uses a practical fiber optic coupler to separate fluorescence excitation and emission. We test both systems by measuring the lifetime of several NIR dyes in DMSO solutions and we show that these systems are capable of detecting lifetimes of solutions with concentrations down to 370 nM and this with short acquisition times. These results are compared with time-correlated single photon counting (TCSPC) measurements for reference.

New intravascular flow sensor using fiber optics

NASA Astrophysics Data System (ADS)

Stenow, Erik N. D.

1994-12-01

A new sensor using fiber optics is suggested for blood flow measurements in small vessels. The sensor principle and a first evaluation on a flow model are presented. The new sensor uses small CO2 gas bubbles as flow markers for optical detection. When the bubbles pass an optical window, light emitted from one fiber is reflected and scattered into another fiber. The sensor has been proven to work in a 3 mm flow model using two 110 micrometers optical fibers and a 100 micrometers steel capillary inserted into a 1 mm guide wire. The evaluation of a sensor archetype shows that the new sensor provides a promising method for intravascular blood flow measurement in small vessels. The linearity for steady state flow is studied in the flow interval 30 - 130 ml/min. comparison with ultrasound Doppler flowmetry was performed for pulsatile flow in the interval 25 - 125 ml/min. with a pulse length between 0.5 and 2 s. The use of intravascular administered CO2 in small volumes is harmless because the gas is rapidly dissolved in whole blood.

Thyroid storm complicated by bicytopenia and disseminated intravascular coagulation.

PubMed

Tokushima, Yoshinori; Sakanishi, Yuta; Nagae, Kou; Tokushima, Midori; Tago, Masaki; Tomonaga, Motosuke; Yoshioka, Tsuneaki; Hyakutake, Masaki; Sugioka, Takashi; Yamashita, Shu-ichi

2014-07-24

Male, 23. Thyroid storm. Delirium • diarrhea • fever • hypertension • hyperventilation • tachycardia • weight loss. -. -. Endocrinology and Metabolic. Unusual clinical course. The clinical presentation of thyroid storm includes fever, tachycardia, hypertension, and neurological abnormalities. It is a serious condition with a high mortality rate. Furthermore, some other complications affect the clinical course of thyroid storm. Although it is reported that prognosis is poor when thyroid storm is complicated by disseminated intravascular coagulation syndrome (DIC) and leukopenia, reports of such cases are rare. A 23-year-old man presented with delirium, high pyrexia, diarrhea, and weight loss of 18 kg over 2 months. According to the criteria of Burch and Wartofsky, he was diagnosed with thyroid storm on the basis of his symptom-complex and laboratory data that confirmed the presence of hyperthyroidism. Investigations also found leukopenia, thrombocytopenia, and disseminated intravascular coagulation, all of which are very rare complications of thyroid storm. We successfully treated him with combined therapy including anti-thyroid medication, despite leukopenia. Early diagnosis and treatment are essential in ensuring a good outcome for patients with this rare combination of medical problems.

Primary Intra-aortic Epstein-Barr Virus-Positive Large B-Cell Lymphoma Presenting as Aortic Mural Thrombosis: An Entity Distinct From Intravascular Large B-Cell Lymphoma.

PubMed

Nakao, Ryuta; Sakashita, Aki; Omoto, Atsushi; Sato, Osamu; Hino, Yoko; Yanagisawa, Akio; Urata, Yoji

2017-12-01

Intravascular selective growth of neoplastic B lymphocytes is a characteristic finding of intravascular large B-cell lymphoma (IVLBCL). However, because neoplastic B cells of IVLBCL grow merely in the lumina of capillaries or small vessels, primary IVLBCL of the great vessels is considered exceptional. To our knowledge, only 2 primary B-cell lymphomas in the lumina of the vena cava have been reported. However, there has been no report of primary B-cell lymphoma with intra-aortic growth. We describe a novel manifestation of primary Epstein-Barr virus-positive large B-cell lymphoma mainly affecting the lumina of the aorta and its major branches in a 76-year-old man. He had a long-term fever that was refractory to antibiotics and aortic mural thrombosis with visceral embolization. Because he had no detectable mass suggesting a malignancy, it was difficult to diagnose while he was alive. He died without anticancer treatment, and the confirmed diagnosis was made at autopsy.

Sinusoidal Obstruction Syndrome During Chemotherapy of Pediatric Cancers and its Successful Management With Defibrotide.

PubMed

Kizilocak, Hande; Dikme, Gürcan; Özdemir, Nihal; Kuruğoğlu, Sebuh; Adaletli, İbrahim; Erkan, Tülay; Celkan, Tiraje

2017-10-01

Sinusoidal obstruction syndrome (SOS) is a life-threatening complication generally occurring after hematopoietic stem cell transplantation. SOS after standard dose chemotherapy in malignancies is rare. Between the year 1995 and 2016, 414 patients were diagnosed with acute lymphoblastic leukemia and 113 patients were diagnosed with Wilms tumor in our institution. Among these patients, 4 patients with acute lymphoblastic leukemia (0.96%) and 2 patients with Wilms tumor (1.7%) developed SOS during treatment. SOS behaves like a local disseminated intravascular coagulation. Defibrotide has proved to be effective in SOS. In this article, we report our experience with defibrotide in SOS.

The off-label use of the Amplatzer muscular VSD occluder for large patent ductus arteriosus: a case report and review.

PubMed

Cubeddu, Roberto J; Babin, Ivan; Inglessis, Ignacio

2014-07-01

A percutaneous approach to the closure of patent ductus arteriosus (PDA) is the preferred procedure in the majority of cases. However, there is little experience with percutaneous closure of unusually large PDA. We report the case of a 28-year-old female with moderate left ventricular dilation and pulmonary hypertension resulting from a large 16 mm PDA. Percutaneous closure was successfully performed using an off-label Amplatzer muscular ventricular septal defect occluder after intravascular ultrasound assessment. Technical challenges, including accurate assessment of defect size and device selection are exemplified along with a comprehensive overview of the available literature.

Clinical Neuropathology practice guide 3-2014: Combined nerve and muscle biopsy in the diagnostic work-up of neuropathy – the Bordeaux experience

PubMed Central

Vital, Anne; Vital, Claude

2014-01-01

Simultaneous combined superficial peroneal nerve and peroneous brevis muscle biopsy, via the same cutaneous incision, allows examination of several tissue specimens and significantly improves the diagnosis of systemic diseases with peripheral nerve involvement. Vasculitides are certainly the most frequently diagnosed on neuro-muscular biopsies, but this procedure is also well advised to asses a diagnosis of sarcoidosis or amyloidosis. More occasionally, combined nerve and muscle biopsy may reveal an unpredicted diagnosis of cholesterol embolism, intra-vascular lymphoma, or enables complementary diagnosis investigations on mitochondrial cytopathy or storage disease. PMID:24618073

Simultaneous determination of the intravenous and oral pharmacokinetic parameters of D,L-verapamil using stable isotope-labelled verapamil.

PubMed

Eichelbaum, M; Somogyi, A; von Unruh, G E; Dengler, H J

1981-01-01

Following i.v. administration, the plasma concentration-time curve of verapamil could best be described by either a mono- or biexponential equation. Total plasma clearance (1.26 1/min) approached liver blood flow (1.51/min), so it can be concluded that its clearance is liver blood flow-dependent. Although absorption was almost complete after oral administration, absolute bioavailability (20%) was low, due to extensive hepatic first-pass metabolism. The approach using stable isotope-labelled and unlabelled drug permits simultaneous administration by the intravascular and extravascular routes, thus allowing determination of absolute bioavailability in a single experiment.

The angiotensin II type 1 receptor blocker losartan attenuates bioprosthetic valve leaflet calcification in a rabbit intravascular implant model.

PubMed

Shin, Hong Ju; Kim, Dae-Hyun; Park, Han Ki; Park, Young Hwan

2016-12-01

There is evidence that angiotensin II type I receptor blocker (ARB) could reduce structural valve deterioration. However, the anticalcification effect on the bioprosthetic heart valve (BHV) has not been investigated. Thus, we investigated the effects of losartan (an ARB) on calcification of implanted bovine pericardial tissue in a rabbit intravascular implant model. A total of 16 male New Zealand White rabbits (20 weeks old, 2.98-3.34 kg) were used in this study. Commercially available BHV leaflet of bovine pericardium was trimmed to the shape of a 3-mm triangle and implanted to both external jugular veins of the rabbit. The ARB group (n = 8) was given 25 mg/kg of powdered losartan daily until 6 weeks after surgery by direct administration in the buccal pouch of the animals. The control group (n = 8) was given 5 ml of normal saline by the same method. After 6 weeks, quantitative calcium determination, histological evaluation and western blot analysis of interleukin-6 (IL-6), osteopontin and bone morphogenetic protein 2 (BMP-2) were performed to investigate the mechanisms of the anticalcification effect of losartan. No deaths or complications such as infection or haematoma were recorded during the experiment. All animals were euthanized on the planned date. The calcium measurement level in the ARB group (2.28 ± 0.65 mg/g) was significantly lower than that in the control group (3.68 ± 1.00 mg/g) (P = 0.0092). Immunohistochemistry analyses revealed that BMP-2-positive reactions were significantly attenuated in the ARB group. Western blot analysis showed that losartan suppressed the expression of IL-6, osteopontin and BMP-2. Our results indicate that losartan significantly attenuates postimplant degenerative calcification of a bovine pericardial bioprosthesis in a rabbit intravascular implant model. Further studies are required to assess the effects of ARBs on BHV tissue in orthotopic implantations using a large animal model. © The Author 2016. Published by Oxford University Press on behalf of the European Association for Cardio-Thoracic Surgery. All rights reserved.

Correction for intravascular activity in the oxygen-15 steady-state technique is independent of the regional hematocrit

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

Lammertsma, A.A.; Baron, J.C.; Jones, T.

1987-06-01

The oxygen-15 steady-state technique to measure the regional cerebral metabolic rate for oxygen requires a correction for the nonextracted intravascular molecular oxygen-15. To perform this correction, an additional procedure is carried out using RBCs labeled with /sup 11/CO or C/sup 15/O. The previously reported correction method, however, required knowledge of the regional cerebral to large vessel hematocrit ratio. A closer examination of the underlying model eliminated this ratio. Both molecular oxygen and carbon monoxide are carried by RBCs and are therefore similarly affected by a change in hematocrit.

Acute viral hepatitis E presenting with haemolytic anaemia and acute renal failure in a patient with glucose-6-phosphate dehydrogenase deficiency.

PubMed

Tomar, Laxmikant Ramkumarsingh; Aggarwal, Amitesh; Jain, Piyush; Rajpal, Surender; Agarwal, Mukul P

2015-10-01

The association of acute hepatitis E viral (HEV) infection with glucose-6-phosphate dehydrogenase (G6PD) deficiency leading to extensive intravascular haemolysis is a very rare clinical entity. Here we discuss such a patient, who presented with acute HEV illness, developed severe intravascular haemolysis and unusually high levels of bilirubin, complicated by acute renal failure (ARF), and was later on found to have a deficiency of G6PD. The patient recovered completely with haemodialysis and supportive management. © The Author(s) 2014.

Intravascular lymphomatosis presenting as acute hemispheric dysfunction.

PubMed

Hwang, Woo Sub; Jung, Chul Won; Ko, Young Hye; Seo, Sang Won; Na, Duk L

2012-11-01

Intravascular lymphomatosis (IVL) is known to affect both hemispheres of the brain and manifests clinically as seizures or dementia. To our knowledge, there have been no cases in which acute hemispheric dysfunction is manifested in IVL. We present a 54-year-old man who showed steroid responsive acute hemispheric dysfunction. A technetium 99m-ethyl cysteinate dimer single-photon emission computed tomographic scan of the brain revealed hypoperfusion in the right hemisphere. The bone marrow biopsy specimen confirmed malignant lymphoid cells in vessels, which suggested IVL. Our case signifies the diversity of clinical manifestations in IVL. Copyright © 2012. Published by Elsevier Inc.

Bothrops jararaca envenomation: Pathogenesis of hemostatic disturbances and intravascular hemolysis.

PubMed

Senise, Luana V; Yamashita, Karine M; Santoro, Marcelo L

2015-11-01

To attain fully functional biological activity, vitamin-K dependent coagulation factors (VKDCF) are γ-carboxylated prior to secretion from liver. Warfarin impairs the γ-carboxylation, and consequently their physiological function. Bothrops jararaca snake venom (BjV) contains several activators of blood coagulation, especially procoagulant enzymes (prothrombin and factor X activators) and thrombin-like enzymes. In order to clarify the relative contribution of prothrombin and factor X activators to the hemostatic disturbances occurring during experimental B. jararaca envenomation, warfarin was used to deplete VKDCF, prior to BjV administration. Male Wistar rats were pretreated with saline (Sal) or warfarin (War) and inoculated subsequently with BjV or saline, thus forming four groups: Sal + Sal (negative control), Sal + BjV (positive control), War + Sal (warfarinization control), and War + BjV. Three hours after inoculation, prothrombin and factor X levels fell 40% and 50%, respectively; levels of both factors decreased more than 97% in the War + Sal and War + BjV groups. Platelet counts dropped 93% and 76% in Sal + BjV and War + BjV, respectively, and plasma fibrinogen levels decreased 86% exclusively in Sal + BjV. After 6 and 24 h, platelet counts and fibrinogen levels increased progressively. A dramatic augmentation in plasma hemoglobin levels and the presence of schizocytes and microcytes in the Sal + BjV group indicated the development of intravascular hemolysis, which was prevented by warfarin pretreatment. Our findings show that intravascular thrombin generation has the foremost role in the pathogenesis of coagulopathy and intravascular hemolysis, but not in the development of thrombocytopenia, in B. jararaca envenomation in rats; in addition, fibrinogenases (metalloproteinases) may contribute to coagulopathy more than thrombin-like enzymes. © 2015 by the Society for Experimental Biology and Medicine.

IVUS Findings in Late and Very Late Stent Thrombosis. A Comparison Between Bare-metal and Drug-eluting Stents.

PubMed

Fuentes, Lara; Gómez-Lara, Josep; Salvatella, Neus; Gonzalo, Nieves; Hernández-Hernández, Felipe; Fernández-Nofrerias, Eduard; Sánchez-Recalde, Ángel; Alfonso, Fernando; Romaguera, Rafael; Ferreiro, José Luis; Roura, Gerard; Teruel, Luis; Gracida, Montserrat; Marcano, Ana Lucrecia; Gómez-Hospital, Joan-Antoni; Cequier, Ángel

2018-05-01

Stent thrombosis (ST) is a life-threatening complication after stent implantation. Intravascular ultrasound is able to discern most causes of ST. The aim of this study was to compare intravascular ultrasound findings between bare-metal stents (BMS) and drug-eluting stents (DES) in patients with late (31 days to 1 year) or very late ST (> 1 year). Of 250 consecutive patients with late or very late ST in 7 Spanish institutions, 114 patients (45.5% BMS and 54.5% DES) were imaged with intravascular ultrasound. Off-line intravascular ultrasound analysis was performed to assess malapposition, underexpansion, and neoatherosclerosis. The median time from stent implantation to ST was 4.0 years with BMS and 3.4 years with DES (P = .04). Isolated malapposition was similarly observed in both groups (36.5% vs 46.8%; P = .18) but was numerically lower with BMS (26.6% vs 48.0%; P = .07) in patients with very late ST. Isolated underexpansion was similarly observed in both groups (13.5% vs 11.3%; P = .47). Isolated neoatherosclerosis occurred only in patients with very late ST and was more prevalent with BMS (22.9%) than with DES (6.0%); P = .02. At 2.9 years' follow-up, there were 0% and 6.9% cardiac deaths, respectively (P = .06) and recurrent ST occurred in 4.0% and 5.2% of patients, respectively (P = .60). Malapposition was the most common finding in patients with late and very late ST and is more prevalent with DES in very late ST. In contrast, neoatherosclerosis was exclusively observed in patients with very late ST and mainly with BMS. Copyright © 2017 Sociedad Española de Cardiología. Published by Elsevier España, S.L.U. All rights reserved.

SU-E-P-10: Imaging in the Cardiac Catheterization Lab - Technologies and Clinical Applications

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

Fetterly, K

2014-06-01

Purpose: Diagnosis and treatment of cardiovascular disease in the cardiac catheterization laboratory is often aided by a multitude of imaging technologies. The purpose of this work is to highlight the contributions to patient care offered by the various imaging systems used during cardiovascular interventional procedures. Methods: Imaging technologies used in the cardiac catheterization lab were characterized by their fundamental technology and by the clinical applications for which they are used. Whether the modality is external to the patient, intravascular, or intracavity was specified. Specific clinical procedures for which multiple modalities are routinely used will be highlighted. Results: X-ray imaging modalitiesmore » include fluoroscopy/angiography and angiography CT. Ultrasound imaging is performed with external, trans-esophageal echocardiography (TEE), and intravascular (IVUS) transducers. Intravascular infrared optical coherence tomography (IVOCT) is used to assess vessel endothelium. Relatively large (>0.5 mm) anatomical structures are imaged with x-ray and ultrasound. IVUS and IVOCT provide high resolution images of vessel walls. Cardiac CT and MRI images are used to plan complex cardiovascular interventions. Advanced applications are used to spatially and temporally merge images from different technologies. Diagnosis and treatment of coronary artery disease frequently utilizes angiography and intra-vascular imaging, and treatment of complex structural heart conditions routinely includes use of multiple imaging modalities. Conclusion: There are several imaging modalities which are routinely used in the cardiac catheterization laboratory to diagnose and treat both coronary artery and structural heart disease. Multiple modalities are frequently used to enhance the quality and safety of procedures. The cardiac catheterization laboratory includes many opportunities for medical physicists to contribute substantially toward advancing patient care.« less

Keep the brain cool--endovascular cooling in patients with severe traumatic brain injury: a case series study.

PubMed

Fischer, Marlene; Lackner, Peter; Beer, Ronny; Helbok, Raimund; Klien, Stephanie; Ulmer, Hanno; Pfausler, Bettina; Schmutzhard, Erich; Broessner, Gregor

2011-04-01

As brain temperature is reported to be extensively higher than core body temperature in traumatic brain injury (TBI) patients, posttraumatic hyperthermia is of particular relevance in the injured brain. To study the influence of prophylactic normothermia on brain temperature and the temperature gradient between brain and core body in patients with severe TBI using an intravascular cooling system and to assess the relationship between brain temperature and intracranial pressure (ICP) under endovascular temperature control. Prospective case series study conducted in the neurologic intensive care unit of a tertiary care university hospital. Seven patients with severe TBI with a Glasgow Coma Scale score of 8 or less were consecutively enrolled. Prophylactic normothermia, defined as a target temperature of 36.5°C, was maintained using an intravascular cooling system. Simultaneous measurements of brain and urinary bladder temperature and ICP were taken over a 72-hour period. The mean bladder temperature in normothermic patients was 36.3 ± 0.4°C, and the mean brain temperature was determined as 36.4 ± 0.5°C. The mean temperature difference between brain and bladder was 0.1°C. We found a significant direct correlation between brain and bladder temperature (r = 0.95). In 52.4% of all measurements, brain temperature was higher than core body temperature. The mean ICP was 18 ± 8 mm Hg. Intravascular temperature management stabilizes both brain and body core temperature; prophylactic normothermia reduces the otherwise extreme increase of intracerebral temperature in patients with severe TBI. The intravascular cooling management proved to be an efficacious and feasible method to control brain temperature and to avoid hyperthermia in the injured brain. We could not find a statistically significant correlation between brain temperature and ICP.

Results of the Intravascular Cooling in the Treatment of Acute Stroke 2 Trial (ICTuS-2)

PubMed Central

Lyden, Patrick; Hemmen, Thomas; Grotta, James; Rapp, Karen; Ernstrom, Karin; Rzesiewicz, Teresa; Parker, Stephanie; Concha, Mauricio; Syed, Hussain; Agarwal, Sachin; Meyer, Brett; Jurf, Julie; Altafullah, Irfan; Raman, Rema

2016-01-01

Background and Purpose Therapeutic hypothermia (TH) is a potent neuroprotectant approved for cerebral protection after neonatal hypoxia-ischemia and cardiac arrest. TH for acute ischemic stroke is safe and feasible in pilot trials. We designed a study protocol to provide safer, faster TH in stroke patients. Methods Safety procedures and 4°C saline infusions for faster cooling were added to the Intravascular Cooling Treatment in Acute Stroke (ICTuS) trial protocol. A femoral venous intravascular cooling catheter following intravenous rt-PA in eligible patients provided 24 hours cooling followed by a 12 hour re-warm. Serial safety assessments and imaging were performed. The primary endpoint was 3-month modified Rankin score 0,1. Results Of the intended 1600 subjects, 120 were enrolled before the study was stopped. Randomly, 63 were to receive hypothermia (HY) plus anti-shivering treatment and 57 normothermia (NT). Compared to prior studies, cooling rates were improved with a cold saline bolus, without fluid overload. The intention-to-treat primary outcome of 90-day mRS 0,1 occurred in 33% HY and 38% NT subjects, OR (95% CL) of 0.81 (0.36, 1.85). Serious adverse events occurred equally. Mortality was 15.9% HY and 8.8% NT subjects, OR (95% CL) of 1.95 (0.56, 7.79). Pneumonia occurred in 19% HY vs. 10.5% in NT subjects, OR (95% CL) of 1.99 (0.63, 6.98). Conclusion Intravascular TH was confirmed to be safe and feasible in rt-PA treated acute ischemic stroke patients. Protocol changes designed to reduce pneumonia risk appeared to fail, although the sample is small. Clinical trial registration clinicaltrials.gov NCT 01123161. PMID:27834742

Multimodality Intracoronary Imaging With Near-Infrared Spectroscopy and Intravascular Ultrasound in Asymptomatic Individuals With High Calcium Scores.

PubMed

Madder, Ryan D; VanOosterhout, Stacie; Klungle, David; Mulder, Abbey; Elmore, Matthew; Decker, Jeffrey M; Langholz, David; Boyden, Thomas F; Parker, Jessica; Muller, James E

2017-10-01

This study sought to determine the frequency of large lipid-rich plaques (LRP) in the coronary arteries of individuals with high coronary artery calcium scores (CACS) and to determine whether the CACS correlates with coronary lipid burden. Combined near-infrared spectroscopy and intravascular ultrasound was performed in 57 vessels in 20 asymptomatic individuals (90% on statins) with no prior history of coronary artery disease who had a screening CACS ≥300 Agatston units. Among 268 10-mm coronary segments, near-infrared spectroscopy images were analyzed for LRP, defined as a bright yellow block on the near-infrared spectroscopy block chemogram. Lipid burden was assessed as the lipid core burden index (LCBI), and large LRP were defined as a maximum LCBI in 4 mm ≥400. Vessel plaque volume was measured by quantitative intravascular ultrasound. Vessel-level CACS significantly correlated with plaque volume by intravascular ultrasound ( r =0.69; P <0.0001) but not with LCBI by near-infrared spectroscopy ( r =0.24; P =0.07). Despite a high CACS, no LRP was detected in 8 (40.0%) subjects. Large LRP having a maximum LCBI in 4 mm ≥400 were infrequent, found in only 5 (25.0%) of 20 subjects and in only 5 (1.9%) of 268 10-mm coronary segments analyzed. Among individuals with a CACS ≥300 Agatston units mostly on statins, CACS correlated with total plaque volume but not LCBI. This observation may have implications on coronary risk among individuals with a high CACS considering that it is coronary LRP, rather than calcification, that underlies the majority of acute coronary events. © 2017 American Heart Association, Inc.

Characterising health care-associated bloodstream infections in public hospitals in Queensland, 2008-2012.

PubMed

Si, Damin; Runnegar, Naomi; Marquess, John; Rajmokan, Mohana; Playford, Elliott G

2016-04-18

To describe the epidemiology and rates of all health care-associated bloodstream infections (HA-BSIs) and of specific HA-BSI subsets in public hospitals in Queensland. Standardised HA-BSI surveillance data were collected in 23 Queensland public hospitals, 2008-2012. HA-BSIs were prospectively classified in terms of place of acquisition (inpatient, non-inpatient); focus of infection (intravascular catheter-associated, organ site focus, neutropenic sepsis, or unknown focus); and causative organisms. Inpatient HA-BSI rates (per 10,000 patient-days) were calculated. There were 8092 HA-BSIs and 9418 causative organisms reported. Inpatient HA-BSIs accounted for 79% of all cases. The focus of infection in 2792 cases (35%) was an organ site, intravascular catheters in 2755 (34%; including 2240 central line catheters), neutropenic sepsis in 1063 (13%), and unknown in 1482 (18%). Five per cent (117 of 2240) of central line-associated BSIs (CLABSIs) were attributable to intensive care units (ICUs). Eight groups of organisms provided 79% of causative agents: coagulase-negative staphylococci (18%), Staphylococcus aureus (15%), Escherichia coli (11%), Pseudomonas species (9%), Klebsiella pneumoniae/oxytoca (8%), Enterococcus species (7%), Enterobacter species (6%), and Candida species (5%). The overall inpatient HA-BSI rate was 6.0 per 10,000 patient-days. The rates for important BSI subsets included: intravascular catheter-associated BSIs, 1.9 per 10,000 patient-days; S. aureus BSIs, 1.0 per 10,000 patient-days; and methicillin-resistant S. aureus BSIs, 0.3 per 10,000 patient-days. The rate of HA-BSIs in Queensland public hospitals is lower than reported by similar studies elsewhere. About one-third of HA-BSIs are attributable to intravascular catheters, predominantly central venous lines, but the vast majority of CLABSIs are contracted outside ICUs. Different sources of HA-BSIs require different prevention strategies.

Pharmacology of colloids and crystalloids.

PubMed

Griffel, M I; Kaufman, B S

1992-04-01

We have attempted to review body fluid distribution by compartments so that the reader understands the physiology of ICF and ECF, and the relationship between interstitial and intravascular fluids. Crystalloids such as NS and RL are distributed to the ECF, whereas colloids primarily remain intravascular for longer periods. Although effective, crystalloids tend to require larger volumes for infusion, and edema remains a problem. Colloids as a group are extremely effective volume expanders, but none is ideal. Albumin, hetastarch, dextran, and the less commonly used colloids each have significant toxicities that must be considered when using them. Intelligent choices can be made to optimize use of these fluids.

Venous gas embolism - Time course of residual pulmonary intravascular bubbles

NASA Technical Reports Server (NTRS)

Butler, B. D.; Luehr, S.; Katz, J.

1989-01-01

A study was carried out to determine the time course of residual pulmonary intravascular bubbles after embolization with known amounts of venous air, using an N2O challenge technique. Attention was also given to the length of time that the venous gas emboli remained as discrete bubbles in the lungs with 100 percent oxygen ventilation. The data indicate that venous gas emboli can remain in the pulmonary vasculature as discrete bubbles for periods lasting up to 43 + or - 10.8 min in dogs ventilated with oxygen and nitrogen. With 100 percent oxygen ventilation, these values are reduced significantly to 19 + or - 2.5 min.

Intravascular low-level laser irradiation in the treatment of psoriasis

NASA Astrophysics Data System (ADS)

Zhu, Jing; Shi, Hong-Min; Zhang, Hui-Guo; Zhang, Mei-Jue; Xu, Jian; Zhou, Min; Hu, Guo-Qiang

1998-11-01

Liu TCY et al have put forward the biological information model on low intensity laser irradiation (BIML): low intensity laser irradiation couples with intracellular messenger through the chromophore absorption in the cell membrane: hot-color laser irradiation activates cAMP phosphodiestererase through Gi protein, or activates phosphoinositide phospholipase C through G protein, or activates one of receptor-associated kinases: cAMP; cold- color laser irradiation activates adenylate cyclase through Gs protein: cAMP$ARUP. In this paper, under the guidance of BIML, we applied the intravascular low intensity He-He laser irradiation on blood to a patient of idiopathic edema, and succeeded.

Th1 differentiation drives the accumulation of intravascular, non-protective CD4 T cells during tuberculosis

PubMed Central

Sallin, Michelle A.; Sakai, Shunsuke; Kauffman, Keith D.; Young, Howard A.; Zhu, Jinfang; Barber, Daniel L.

2017-01-01

SUMMARY Recent data indicate that the differentiation state of Th1 cells determines their protective capacity against tuberculosis. Therefore, we examined the role of Th1 polarizing factors in the generation of protective and non-protective subsets of Mtb-specific Th1 cells. We find IL-12/23p40 promotes Th1 cell expansion and maturation beyond the CD73+CXCR3+T-betdim stage, and T-bet prevents deviation of Th1 cells into Th17 cells. Nevertheless, IL-12/23p40 and T-bet are also essential for the production of a prominent subset of intravascular CX3CR1+KLRG1+ Th1 cells that persists poorly and can neither migrate into the lung parenchyma nor control Mtb growth. Furthermore, T-bet suppresses development of CD69+CD103+ tissue resident phenotype effectors in lung. In contrast, Th1 cell-derived IFNγ inhibits the accumulation of intravascular CX3CR1+KLRG1+ Th1 cells. Thus, although IL-12 and T-bet are essential host survival factors, they simultaneously oppose lung CD4 T cell responses at several levels, demonstrating the dual nature of Th1 polarization in tuberculosis. PMID:28355562

A Broadband Polyvinylidene Difluoride-Based Hydrophone with Integrated Readout Circuit for Intravascular Photoacoustic Imaging.

PubMed

Daeichin, Verya; Chen, Chao; Ding, Qing; Wu, Min; Beurskens, Robert; Springeling, Geert; Noothout, Emile; Verweij, Martin D; van Dongen, Koen W A; Bosch, Johan G; van der Steen, Antonius F W; de Jong, Nico; Pertijs, Michiel; van Soest, Gijs

2016-05-01

Intravascular photoacoustic (IVPA) imaging can visualize the coronary atherosclerotic plaque composition on the basis of the optical absorption contrast. Most of the photoacoustic (PA) energy of human coronary plaque lipids was found to lie in the frequency band between 2 and 15 MHz requiring a very broadband transducer, especially if a combination with intravascular ultrasound is desired. We have developed a broadband polyvinylidene difluoride (PVDF) transducer (0.6 × 0.6 mm, 52 μm thick) with integrated electronics to match the low capacitance of such a small polyvinylidene difluoride element (<5 pF/mm(2)) with the high capacitive load of the long cable (∼100 pF/m). The new readout circuit provides an output voltage with a sensitivity of about 3.8 μV/Pa at 2.25 MHz. Its response is flat within 10 dB in the range 2 to 15 MHz. The root mean square (rms) output noise level is 259 μV over the entire bandwidth (1-20 MHz), resulting in a minimum detectable pressure of 30 Pa at 2.25 MHz. Copyright © 2016 World Federation for Ultrasound in Medicine & Biology. Published by Elsevier Inc. All rights reserved.

Pharmacokinetics, tissue distribution, and metabolism of nitrofurantoin in the channel catfish (Ictalurus punctatus)

USGS Publications Warehouse

Stehly, G.R.; Plakas, S.M.

1993-01-01

The pharmacokinetics, tissue distribution, and metabolism of the drug nitrofurantoin were examined in the channel catfish (Ictalurus punctatus) after intravascular or oral dosing. Mean plasma concentrations of nitrofurantoin after intravascular administration at 1 and 10 mg/kg of body weight were best fit to two- and three-compartment pharmacokinetic models, respectively. Nitrofurantoin was rapidly eliminated from the plasma after intravascular dosing; at 1 and 10 mg/kg, the terminal half-lives were 23 and 46 min, respectively. After oral dosing at 1 mg/kg, peak plasma concentrations (0.06 mu g/ml) occurred at 2 h; the bioavailability was 17%. Residues of nitrofurantoin and its metabolites in the tissues were initially eliminated rapidly but persisted at the later sampling times. Residue concentrations were highest in the plasma and excretory tissues. Approximately 21% and 4% of the oral dose were eliminated in the urine and bile, respectively. Parent nitrofurantoin was the major radiolabelled compound found in the urine; however, the percentage of total residues composed of metabolites increased with time. Biliary residues consisted mostly of nitrofurantoin metabolites. High-performance liquid chromatography revealed the presence of at least five metabolites in the urine and bile.

Intravascular hemolysis and the pathophysiology of sickle cell disease

PubMed Central

Kato, Gregory J.; Steinberg, Martin H.; Gladwin, Mark T.

2017-01-01

Hemolysis is a fundamental feature of sickle cell anemia that contributes to its pathophysiology and phenotypic variability. Decompartmentalized hemoglobin, arginase 1, asymmetric dimethylarginine, and adenine nucleotides are all products of hemolysis that promote vasomotor dysfunction, proliferative vasculopathy, and a multitude of clinical complications of pulmonary and systemic vasculopathy, including pulmonary hypertension, leg ulcers, priapism, chronic kidney disease, and large-artery ischemic stroke. Nitric oxide (NO) is inactivated by cell-free hemoglobin in a dioxygenation reaction that also oxidizes hemoglobin to methemoglobin, a non–oxygen-binding form of hemoglobin that readily loses heme. Circulating hemoglobin and heme represent erythrocytic danger-associated molecular pattern (eDAMP) molecules, which activate the innate immune system and endothelium to an inflammatory, proadhesive state that promotes sickle vaso-occlusion and acute lung injury in murine models of sickle cell disease. Intravascular hemolysis can impair NO bioavailability and cause oxidative stress, altering redox balance and amplifying physiological processes that govern blood flow, hemostasis, inflammation, and angiogenesis. These pathological responses promote regional vasoconstriction and subsequent blood vessel remodeling. Thus, intravascular hemolysis represents an intrinsic mechanism for human vascular disease that manifests clinical complications in sickle cell disease and other chronic hereditary or acquired hemolytic anemias. PMID:28248201

Evaluation of lumbar transforaminal epidural injections with needle placement and contrast flow patterns: a prospective, descriptive report.

PubMed

Manchikanti, Laxmaiah; Cash, Kim A; Pampati, Vidyasagar; Damron, Kim S; McManus, Carla D

2004-04-01

Transforaminal epidural steroid injection is one of the commonly employed modalities of treatment in managing nerve root pain. However, there have been no controlled prospective evaluations of epidural and nerve root contrast distribution patterns and other aspects of fluoroscopically directed lumbosacral transforaminal epidural steroid injections. To evaluate contrast flow patterns and intravascular needle placement of fluoroscopically guided lumbosacral transforaminal epidural injections. A prospective, observational study. A total of 100 consecutive patients undergoing fluoroscopically guided transforaminal epidural steroid injections were evaluated. The contrast flow patterns, ventral or dorsal epidural filling, nerve root filling, C-arm time, and intravascular needle placement were evaluated. Ventral epidural filling was seen in 88% of the procedures, in contrast to dorsal filling noted in 9% of the procedures. Nerve root filling was seen in 97% of the procedures. Total intravenous placement of the needle was noted in 22% of the procedures, whereas negative flashback and aspiration was noted in 5% of the procedures. Lumbosacral transforaminal epidural injections, performed under fluoroscopic visualization, provide excellent nerve root filling and ventral epidural filling patterns. However, unrecognized intravascular needle placement with negative flashback or aspiration was noted in 5% of the procedures.

Computational analysis of the effectiveness of blood flushing with saline injection from an intravascular diagnostic catheter

PubMed Central

Ghata, Narugopal; Aldredge, Ralph C.; Bec, Julien; Marcu, Laura

2015-01-01

SUMMARY Optical techniques including fluorescence lifetime spectroscopy have demonstrated potential as a tool for study and diagnosis of arterial vessel pathologies. However, their application in the intravascular diagnostic procedures has been hampered by the presence of blood hemoglobin that affects the light delivery to and the collection from the vessel wall. We report a computational fluid dynamics model that allows for the optimization of blood flushing parameters in a manner that minimizes the amount of saline needed to clear the optical field of view and reduces any adverse effects caused by the external saline jet. A 3D turbulence (k−ω) model was employed for Eulerian–Eulerian two-phase flow to simulate the flow inside and around a side-viewing fiber-optic catheter. Current analysis demonstrates the effects of various parameters including infusion and blood flow rates, vessel diameters, and pulsatile nature of blood flow on the flow structure around the catheter tip. The results from this study can be utilized in determining the optimal flushing rate for given vessel diameter, blood flow rate, and maximum wall shear stress that the vessel wall can sustain and subsequently in optimizing the design parameters of optical-based intravascular catheters. PMID:24953876

Transcapillary protein flux following blood volume modification in dog.

PubMed

Miki, K; Nose, H; Tanaka, Y; Morimoto, T

1984-01-01

The net fluid and protein movements between intravascular and interstitial space following blood withdrawal and retransfusion of 15% of circulating blood volume were measured in dogs using a continuous monitoring method of circulating blood volume. A significant (p less than 0.01) increase in transvascular fluid shift was observed after the start of blood withdrawal and a new equilibrium state was reached within 15 to 20 min. Associated with the fluid shift, a significant increase in plasma protein of about 1 g was observed. On the other hand, blood retransfusion caused significant (p less than 0.01) increases in the shift of fluid and protein from intravascular space to interstitial space. The magnitudes of the shift of fluid and protein were almost identical in both blood withdrawal and retransfusion. The Kedem-Katchalsky transport equation was applied to the results obtained in the present study in order to analyze the relative role of diffusion and convection and to estimate the reflection coefficient for protein. A significant (p less than 0.01) linear relationship was observed between fluid and protein movement. These results suggest that the convective process is involved in the shift of protein between intravascular and interstitial space observed after blood volume modification.

Whole plant based treatment of hypercholesterolemia with Crataegus laevigata in a zebrafish model

PubMed Central

2012-01-01

Background Consumers are increasingly turning to plant-based complementary and alternative medicines to treat hypercholesterolemia. Many of these treatments are untested and their efficacy is unknown. This multitude of potential remedies necessitates a model system amenable to testing large numbers of organisms that maintains similarity to humans in both mode of drug administration and overall physiology. Here we develop the larval zebrafish (4–30 days post fertilization) as a vertebrate model of dietary plant-based treatment of hypercholesterolemia and test the effects of Crataegus laevigata in this model. Methods Larval zebrafish were fed high cholesterol diets infused with fluorescent sterols and phytomedicines. Plants were ground with mortar and pestle into a fine powder before addition to food. Fluorescent sterols were utilized to optically quantify relative difference in intravascular cholesterol levels between groups of fish. We utilized the Zeiss 7-Live Duo high-speed confocal platform in order to both quantify intravascular sterol fluorescence and to capture video of the heart beat for determination of cardiac output. Results In this investigation we developed and utilized a larval zebrafish model to investigate dietary plant-based intervention of the pathophysiology of hypercholesterolemia. We found BODIPY-cholesterol effectively labels diet-introduced intravascular cholesterol levels (P < 0.05, Student’s t-test). We also established that zebrafish cardiac output declines as cholesterol dose increases (difference between 0.1% and 8% (w/w) high cholesterol diet-treated cardiac output significant at P < 0.05, 1-way ANOVA). Using this model, we found hawthorn leaves and flowers significantly reduce intravascular cholesterol levels (P < 0.05, 1-way ANOVA) and interact with cholesterol to impact cardiac output in hypercholesterolemic fish (2-way ANOVA, P < 0.05 for interaction effect). Conclusions The results of this study demonstrate that the larval zebrafish has the potential to become a powerful model to test plant based dietary intervention of hypercholesterolemia. Using this model we have shown that hawthorn leaves and flowers have the potential to affect cardiac output as well as intravascular cholesterol levels. Further, our observation that hawthorn leaves and flowers interact with cholesterol to impact cardiac output indicates that the physiological effects of hawthorn may depend on diet. PMID:22824306

Real-Time Imaging Reveals the Dynamics of Leukocyte Behaviour during Experimental Cerebral Malaria Pathogenesis

PubMed Central

Pai, Saparna; Qin, Jim; Cavanagh, Lois; Mitchell, Andrew; El-Assaad, Fatima; Jain, Rohit; Combes, Valery; Hunt, Nicholas H.; Grau, Georges E. R.; Weninger, Wolfgang

2014-01-01

During experimental cerebral malaria (ECM) mice develop a lethal neuropathological syndrome associated with microcirculatory dysfunction and intravascular leukocyte sequestration. The precise spatio-temporal context in which the intravascular immune response unfolds is incompletely understood. We developed a 2-photon intravital microscopy (2P-IVM)-based brain-imaging model to monitor the real-time behaviour of leukocytes directly within the brain vasculature during ECM. Ly6Chi monocytes, but not neutrophils, started to accumulate in the blood vessels of Plasmodium berghei ANKA (PbA)-infected MacGreen mice, in which myeloid cells express GFP, one to two days prior to the onset of the neurological signs (NS). A decrease in the rolling speed of monocytes, a measure of endothelial cell activation, was associated with progressive worsening of clinical symptoms. Adoptive transfer experiments with defined immune cell subsets in recombinase activating gene (RAG)-1-deficient mice showed that these changes were mediated by Plasmodium-specific CD8+ T lymphocytes. A critical number of CD8+ T effectors was required to induce disease and monocyte adherence to the vasculature. Depletion of monocytes at the onset of disease symptoms resulted in decreased lymphocyte accumulation, suggesting reciprocal effects of monocytes and T cells on their recruitment within the brain. Together, our studies define the real-time kinetics of leukocyte behaviour in the central nervous system during ECM, and reveal a significant role for Plasmodium-specific CD8+ T lymphocytes in regulating vascular pathology in this disease. PMID:25033406

Joint learning of ultrasonic backscattering statistical physics and signal confidence primal for characterizing atherosclerotic plaques using intravascular ultrasound.

PubMed

Sheet, Debdoot; Karamalis, Athanasios; Eslami, Abouzar; Noël, Peter; Chatterjee, Jyotirmoy; Ray, Ajoy K; Laine, Andrew F; Carlier, Stephane G; Navab, Nassir; Katouzian, Amin

2014-01-01

Intravascular Ultrasound (IVUS) is a predominant imaging modality in interventional cardiology. It provides real-time cross-sectional images of arteries and assists clinicians to infer about atherosclerotic plaques composition. These plaques are heterogeneous in nature and constitute fibrous tissue, lipid deposits and calcifications. Each of these tissues backscatter ultrasonic pulses and are associated with a characteristic intensity in B-mode IVUS image. However, clinicians are challenged when colocated heterogeneous tissue backscatter mixed signals appearing as non-unique intensity patterns in B-mode IVUS image. Tissue characterization algorithms have been developed to assist clinicians to identify such heterogeneous tissues and assess plaque vulnerability. In this paper, we propose a novel technique coined as Stochastic Driven Histology (SDH) that is able to provide information about co-located heterogeneous tissues. It employs learning of tissue specific ultrasonic backscattering statistical physics and signal confidence primal from labeled data for predicting heterogeneous tissue composition in plaques. We employ a random forest for the purpose of learning such a primal using sparsely labeled and noisy samples. In clinical deployment, the posterior prediction of different lesions constituting the plaque is estimated. Folded cross-validation experiments have been performed with 53 plaques indicating high concurrence with traditional tissue histology. On the wider horizon, this framework enables learning of tissue-energy interaction statistical physics and can be leveraged for promising clinical applications requiring tissue characterization beyond the application demonstrated in this paper. Copyright © 2013 Elsevier B.V. All rights reserved.

A Concurrent Flow Model for Extraction during Transcapillary Passage

PubMed Central

Bassingthwaighte, James B.

2010-01-01

A model for capillary-tissue exchange in a uniformly perfused organ with uniform capillary transit times and no diffusional capillary interactions was designed to permit the exploration of the influences of various parameters on the interpretation of indicator-dilution curves obtained at the venous outflow following the simultaneous injection of tracers into the arterial inflow. These parameters include tissue geometric factors, longitudinal diffusion and volumes of distribution of tracers in blood and tissue, hematocrit, volumes of nonexchanging vessels and the sampling system, capillary permeability, P. capillary surface area, S, and flow of blood- or solute-containing fluid, Fs′. An assumption of instantaneous radial diffusion in the extravascular region is appropriate when intercapillary distances are small, as they are in the heart, or permeabilities are low, as they are for lipophobic solutes. Numerical solutions were obtained for dispersed input functions similar to normal intravascular dye-dilution curves. Axial extravascular diffusion showed a negligible influence at low permeabilities. The “instantaneous extraction” of a permeating solute can provide an estimate of PS/Fs′, the ratio of the capillary permeability–surface area product to the flow, when PS/Fs′ lies between approximately 0.05 and 3.0; the limits of the range depend on the extravascular volume of distribution and the influences of intravascular dispersion. The most accurate estimates were obtained when experiments were designed so that PS/Fs′ was between 0.2 and 1.0 or peak extractions were between 0.1 and 0.6. PMID:4608628

[Current state and development of artificial lungs].

PubMed

Mei, Zaoxian; Sun, Xin; Wu, Qi

2010-12-01

The artificial lung is a technical device for providing life support; it will be put in use when the natural lungs are failing and are not able to maintain sufficient oxygenation of the body's organ systems. From the viewpoint of long-term development, the artificial lung should be permanently implanted in the body, so that it will substitute for the human pulmonary function partially or completely. In this paper, four artificial lung technologies were expounded with reference to the development and research process of artificial lung. They were extracorporeal membrane oxygenation, intravascular artificial lung, implantable artificial lung, and pumpless extracorporeal lung assist. In this paper were described the structure of the four kinds of artificial lung, the working principle, and their advantages, disadvantages and indications. The prospect of artificial lung was evaluated in the light of the data from the existing animal experiments and from the clinical experience of the centers.

Bedside inferior vena cava filter placement by intravascular ultrasound in critically ill patients is safe and effective for an extended time.

PubMed

Glocker, Roan J; Awonuga, Oluwafunmi; Novak, Zdenek; Pearce, Benjamin J; Patterson, Mark; Matthews, Thomas C; Jordan, William D; Passman, Marc A

2014-10-01

Bedside inferior vena cava filter (IVCF) placement by intravascular ultrasound (IVUS) guidance has previously been shown to be a safe and effective technique, especially for critically ill patients, with initial experience of a prospectively implemented algorithm. The purpose of this study was to evaluate the effectiveness of IVUS-guided filter placement in critically ill patients with experience now extending out 5 years from implementation. All patients undergoing bedside IVUS-guided IVCF placement from 2008 to 2012 were identified. Records were reviewed on the basis of IVCF reporting standards. Outcomes data including technical success, complications, and mortality were analyzed at 30 days. During the 5-year period, 398 patients underwent attempted bedside IVCF placement by IVUS. Technical feasibility was possible in 396 cases (99.5%); two bedside procedures were aborted because of inadequate IVUS visualization. Overall technical success was achieved in 393 of 396 (99.2%), with malpositioned IVCF in three cases. An optional IVCF was used in 372 (93.9%) and a permanent IVCF in 24 (6.1%). Single-puncture technique was performed in 388 (97.4%); additional dual access was required in 10 (2.6%). Periprocedural complications were rare (3.0%) and included malpositioning that required retrieval and repositioning or an additional IVCF (3), filter tilt ≥20 degrees (4), arteriovenous fistulas (2), insertion site thrombosis (2), and hematoma (1). Comparison of the first 100 procedures performed within the sample population with the last 100 procedures revealed an overall success rate of 96% in the first 100 compared with 100% in the last 100 (P = .043). There were no deaths related to pulmonary embolism or IVCF-related problems. On the basis of 5 years of experience with bedside IVCF placement in critically ill patients, the IVUS-guided IVCF technique continues to be a safe and effective option in this high-risk population, with a time-dependent improvement in outcome measures. Copyright © 2014 Society for Vascular Surgery. Published by Elsevier Inc. All rights reserved.

Laser radar: historical prospective-from the East to the West

NASA Astrophysics Data System (ADS)

Molebny, Vasyl; McManamon, Paul; Steinvall, Ove; Kobayashi, Takao; Chen, Weibiao

2017-03-01

This article discusses the history of laser radar development in America, Europe, and Asia. Direct detection laser radar is discussed for range finding, designation, and topographic mapping of Earth and of extraterrestrial objects. Coherent laser radar is discussed for environmental applications, such as wind sensing and for synthetic aperture laser radar development. Gated imaging is discussed through scattering layers for military, medical, and security applications. Laser microradars have found applications in intravascular studies and in ophthalmology for vision correction. Ghost laser radar has emerged as a new technology in theoretical and simulation applications. Laser radar is now emerging as an important technology for applications such as self-driving cars and unmanned aerial vehicles. It is also used by police to measure speed, and in gaming, such as the Microsoft Kinect.

Pathophysiology of fat embolism: a rabbit model.

PubMed

Blankstein, Michael; Byrick, Robert J; Richards, Robin R; Mullen, J Brendan; Zdero, Rad; Schemitsch, Emil H

2011-11-01

The objective of this study was to assess the effects of fat embolism on rabbit physiology. After anesthetic administration, both femoral condyles of the right knee only of 23 New Zealand white rabbits were exposed through a medial parapatellar approach to the knee. In the pulmonary fat embolism group (n = 15), the femoral canal was drilled in a retrograde fashion and then reamed and pressurized with a 1- to 1.5-mL cement injection. In the no-pressurization group (n = 4), after reaming, no cement was injected. In the control group (n = 4), the knee incision was immediately closed. Animals were then observed for 5 hours. Hemodynamics and blood gases were recorded at standard intervals. Postmortem, the lungs were removed en bloc and fixed for histologic assessment and quantitative histomorphometry. Four intraoperative deaths occurred in the pulmonary fat embolism group immediately after pressurization and may have been associated with hypotension and cardiac arrest. In the pulmonary fat embolism group, pulmonary artery pressure increased, and both mean arterial pressure and PaO2 decreased after pressurization. Approximately 2% of lung volume was occupied by intravascular fat and there were no signs of perivascular inflammation. Control and no-pressurization animals remained stable throughout the experiment. This model simulates pulmonary fat embolism after long-bone fractures. Despite cardiorespiratory dysfunction, there was no evidence of fat initiating pulmonary inflammation based on histologic data within the timeframe of the investigation.

Penile necrosis secondary to purpura fulminans: a case report and review of literature.

PubMed

Hogarth, David B; Cheon, Paul M; Kassam, Javeed; Seal, Alexander E; Kavanagh, Alexander G

2017-02-01

We report the case of a 60-year-old Hispanic male with widespread necrotic purpuric lesions involving the penile, suprapubic, inguinal and hip dermis due to purpura fulminans. Purpura fulminans describes a rare syndrome involving intravascular thrombosis and hemorrhagic infarction of the skin; this rapidly progressing syndrome features vascular collapse and disseminated intravascular coagulation. This patient's penile necrosis involved the majority of the penile shaft and glans penis, and ultimately required partial glansectomy and repeated debridement for treatment. Subsequently, full thickness skin grafting was completed for reconstruction with good effect. While reports of penile necrosis secondary to various causes are documented in the literature, no prior reports describe penile necrosis secondary to purpura fulminans.

Ultrastructural blood-brain barrier alterations and edema formation in acute spinal cord trauma.

PubMed

Goodman, J H; Bingham, W G; Hunt, W E

1976-04-01

Endothelial changes leading to edema formation are examined in the primate spinal cord (Macaca mulatta) following a lesion created by a 20-gm weight falling 15 cm onto the exposed dura. Intravascular perfusion of a paraformaldehydeglutaraldehyde solution followed by carbon black provides adequate fixation of vascular structures and glial elements. Myelin is poorly preserved. Ultrastructural alterations of the blood-brain barrier consist of loss of integrity of the endothelial tight junctions. Edema caused by vascular disruption and parenchymatous extravasation of intravascular contents is observed along with glial swelling. Interglial gap junctions persist in areas of marked cellular seperation and do not impede the migration of edema fluid.

Hypoglycemic depression of RES function.

PubMed

Buchanan, B J; Filkins, J P

1976-07-01

The intravascular removal rates of colloidal carbon and of biologically active endotoxin by the reticuloendothelial system (RES) were evaluated as a function of blood-glucose levels. There was a significant negative correlation of carbon clearance half time on blood glucose in both saline-treated and insulin-treated rats. Insulin hypoglycemia depressed RES carbon clearance with the maximal effect occurring at blood glucose values below 30 mg/dl. Insulin hypoglycemia also severely impaired the intravascular removal of endotoxin as evaluated by lethality bioassay in lead-sensitized rats. It is concluded that blood glucose may modulate RES phagocytic function and that the hypoglycemia of endotoxin shock may augment the shock state due to impairment of RES host defense clearance functions.

Intravascular ultrasound guided directional atherectomy versus directional atherectomy guided by angiography for the treatment of femoropopliteal in-stent restenosis.

PubMed

Krishnan, Prakash; Tarricone, Arthur; K-Raman, Purushothaman; Majeed, Farhan; Kapur, Vishal; Gujja, Karthik; Wiley, Jose; Vasquez, Miguel; Lascano, Rheoneil A; Quiles, Katherine G; Distin, Tashanne; Fontenelle, Ran; Atallah-Lajam, Farah; Kini, Annapoorna; Sharma, Samin

2018-01-01

The aim of this study was to compare 1-year outcomes for patients with femoropopliteal in-stent restenosis using directional atherectomy guided by intravascular ultrasound (IVUS) versus directional atherectomy guided by angiography. This was a retrospective analysis for patients with femoropopliteal in-stent restenosis treated with IVUS-guided directional atherectomy versus directional atherectomy guided by angiography from a single center between March 2012 and February 2016. Clinically driven target lesion revascularization was the primary endpoint and was evaluated through medical chart review as well as phone call follow up. Directional atherectomy guided by IVUS reduces clinically driven target lesion revascularization for patients with femoropopliteal in-stent restenosis.

Catheter design optimization for practical intravascular photoacoustic imaging (IVPA) of vulnerable plaques

NASA Astrophysics Data System (ADS)

Iskander-Rizk, Sophinese; Wu, Min; Springeling, Geert; Mastik, Frits; Beurskens, Robert H. S. H.; van der Steen, Antonius F. W.; van Soest, Gijs

2018-02-01

Intravascular photoacoustic/ultrasound imaging (IVPA/US) can image the structure and composition of atherosclerotic lesions identifying lipid-rich plaques ex vivo and in vivo. In the literature, multiple IVPA/US catheter designs were presented and validated both in ex-vivo models and preclinical in-vivo situations. Since the catheter is a critical component of the imaging system, we discuss here a catheter design oriented to imaging plaque in a realistic and translatable setting. We present a catheter optimized for light delivery, manageable flush parameters and robustness with reduced mechanical damage risks at the laser/catheter joint interface. We also show capability of imaging within sheath and in water medium.

Plasmapheresis in severe septic shock with disseminated intravascular coagulation.

PubMed

Zilow, E P; Selle, B; Zilow, G

1994-01-01

An 18-year-old female with CNS relapse of acute lymphoblastic leukemia after previous complete remission of the disease underwent chemotherapy. Due to the therapy she suffered from profound suppression of bone marrow with consecutive thrombocytopenia and leukopenia. Despite prophylactic treatment, severe septicemia occurred with septic shock, hemolysis and disseminated intravascular coagulation (DIC). As the clinical course became uncontrollable by means of conventional therapy, including broad-spectrum antibiotics, substitution of fresh frozen plasma, antithrombin III and heparin therapy, plasma exchange was used as a rescue therapy. This method succeeded in effective replacement of clotting factors and normalization of coagulation, in removal of fibrinogen degradation products and probably of toxins and shock mediators. The patient recovered from shock.

[Usefulness of FDG-PET/CT for the diagnosis of intravascular large B-cell lymphoma presenting with fever of unknown origin and renal dysfunction].

PubMed

Yago, Kazuhiro; Yanagita, Soshi; Aono, Maki; Matsuo, Ken; Shimada, Hideto

2009-06-01

A 76-year-old man presented with fever of unknown origin and renal dysfunction. Laboratory examination revealed anemia, thrombocytopenia, hypoalbuminemia, proteinuria, and elevations of C-reactive protein, lactic dehydrogenase, creatinine and ferritin. (18)F-fluorodeoxyglucose positron emission tomography/computed tomography (FDG-PET/CT) imaging showed FDG accumulation in the renal cortex and spleen. Based on the imaging study, renal biopsy was performed and histological diagnosis of intravascular large B-cell lymphoma (IVLBCL) was made. Renal impairment due to IVLBCL is uncommon and is often difficult to diagnose early. FDG-PET/CT may be a useful tool for the early diagnosis of IVLBCL.

Case for diagnosis*

PubMed Central

Fabre, Andréa Buosi; Passos, Paola C. Vieira da Rosa; de Lima, Brunno Zeni; Fabricio, Lincoln; Fillus, José; Bonalumi, Aguinaldo

2014-01-01

Intravascular papillary endothelial hyperplasia is a benign vascular lesion caused by proliferation of endothelium. It is reactive to thrombotic or inflammatory stimuli in the vessel wall.We report the case of a 14-yearold male patient with a violet-colored erythematous tumoral lesion of progressive growth in the occipital region. The diagnosis of intravascular papillary endothelial hyperplasia (IPEH) was confirmed by clinical and histopathological findings. Total lesion exeresis was performed with no recurrence up to date. IPEH presents clinical importance due to its clinical and histological resemblance to angiosarcoma. In order to differentiate it from angiosarcoma, distinguishing features of the benign disease should be considered, such as lack of cellular atypia and rare mitotic activity.Prognosis is good. PMID:25054765

Emerging Technology Update Intravascular Photoacoustic Imaging of Vulnerable Atherosclerotic Plaque.

PubMed

Wu, Min; Fw van der Steen, Antonius; Regar, Evelyn; van Soest, Gijs

2016-10-01

The identification of vulnerable atherosclerotic plaques in the coronary arteries is emerging as an important tool for guiding atherosclerosis diagnosis and interventions. Assessment of plaque vulnerability requires knowledge of both the structure and composition of the plaque. Intravascular photoacoustic (IVPA) imaging is able to show the morphology and composition of atherosclerotic plaque. With imminent improvements in IVPA imaging, it is becoming possible to assess human coronary artery disease in vivo . Although some challenges remain, IVPA imaging is on its way to being a powerful tool for visualising coronary atherosclerotic features that have been specifically associated with plaque vulnerability and clinical syndromes, and thus such imaging might become valuable for clinical risk assessment in the catheterisation laboratory.

Thyroid storm with multiple organ failure, disseminated intravascular coagulation, and stroke with a normal serum FT3 level.

PubMed

Harada, Yuko; Akiyama, Hisanao; Yoshimoto, Tatsuji; Urao, Yasuko; Ryuzaki, Munekazu; Handa, Michiko

2012-01-01

Thyroid storm is a rare disorder with a sudden onset, rapid progression and high mortality. We experienced a case of thyroid storm which had a devastating course, including multiple organ failure (MOF), severe hypoglycemia, disseminated intravascular coagulation (DIC), and stroke. It was difficult to make a diagnosis of thyroid storm in the present patient, because she did not have a history of thyroid disease and her serum FT3 level was normal. Clinicians should be aware that thyroid storm can occur even when there is an almost normal level of thyroid hormones, and that intensive anticoagulation is required for patients with atrial fibrillation to prevent stroke after thyroid storm.

Three-dimensional segmentation of luminal and adventitial borders in serial intravascular ultrasound images

NASA Technical Reports Server (NTRS)

Shekhar, R.; Cothren, R. M.; Vince, D. G.; Chandra, S.; Thomas, J. D.; Cornhill, J. F.

1999-01-01

Intravascular ultrasound (IVUS) provides exact anatomy of arteries, allowing accurate quantitative analysis. Automated segmentation of IVUS images is a prerequisite for routine quantitative analyses. We present a new three-dimensional (3D) segmentation technique, called active surface segmentation, which detects luminal and adventitial borders in IVUS pullback examinations of coronary arteries. The technique was validated against expert tracings by computing correlation coefficients (range 0.83-0.97) and William's index values (range 0.37-0.66). The technique was statistically accurate, robust to image artifacts, and capable of segmenting a large number of images rapidly. Active surface segmentation enabled geometrically accurate 3D reconstruction and visualization of coronary arteries and volumetric measurements.

Endovascular retrieval of dental needle retained in the internal carotid artery.

PubMed

Moore, Kenneth; Khan, Nickalus R; Michael, L Madison; Arthur, Adam S; Hoit, Daniel

2017-03-08

Intravascular foreign bodies are a known complication of medical and dental procedures. Dental anesthetic needles may be broken off and retained in the oropharynx. These needles have occasionally been reported to migrate through the oral mucosa in to deeper structures. Here we present the case of a 57-year-old man who had a retained dental needle that had migrated into his internal carotid artery. The needle was removed using endovascular techniques. To our knowledge, this is the first report of a retained dental needle being retrieved using this method. We review the literature on intravascular foreign bodies, retained dental needles, and endovascular techniques for retrieval of such foreign bodies. 2017 BMJ Publishing Group Ltd.

A rare case of suspected intravascular large B-cell lymphoma forming nodular masses in the brain and around the prostate and seminal vesicle.

PubMed

Ogasawara, Takuto; Ikehata, Yoshinori; Kato, Ryuichi; Miyao, Noriomi; Konishi, Yasuhiro; Kon, Shinichiro

2018-05-01

Intravascular large B-cell lymphoma (IVLBCL) is a rare subtype of diffuse large B-cell lymphoma (DLBCL). Furthermore, tumorigenesis is extremely rare. An 80-year-old man was admitted to our hospital with nervous symptoms. Imaging tests showed a brain tumor and mass lesions in the seminal vesicle and retroperitoneum. Transrectal biopsy of the seminal vesicle helped diagnose the patient with DLBCL. The patient's general status deteriorated rapidly, and he died on the 23rd day after admission. An autopsy was performed and the pathological diagnosis was DLBCL, specifically suspected as IVLBCL, with nodular masses in the brain and seminal vesicle.

Registration of Intravascular Pressure Curves: Magneto-Mechanical Evaluation

NASA Astrophysics Data System (ADS)

Maldonado-Moreles, Martín A.; Córdova-Fraga, T.; Cano, M. E.; Solorio-Meza, Sergio E.; Sosa, M. A.

2008-08-01

In this work, graphs of the intravascular blood pressures at both the left primitive carotid artery and the left jugular vein are presented, by using a "magneto-mechanical" technique with pulse-pressure gauge, a device designed especially to register the magnetic flux variability of a magnetic marker placed superficially on the skin over a blood vessel. It is presented the implementation of a device used for registration of the magnetic induction generated by the periodical movements of a magnetic marker (MM) by using a magnetoresistive transductor, which is placed superficially on the skin (non-invasive) over a blood vessel, at the cervical level in the path of the left carotid, identified by the amplitude of the arterial pulse.

Intravascular low-intensity He-Ne laser irradiation therapy on idiopathic edema

NASA Astrophysics Data System (ADS)

Gao, Yunqing; Liu, T. C.; Tang, Xiang-Jun

1998-11-01

194 patients with psoriasis were treated by intravascular low level laser irradiation combined with Vit C 2.0g iv and O2 inhale to the nose. An hour once a day, for 5-40 times, and 13.06 times in average, ten times with 4-7 days intervals. The results: cured 23 cases, good effected 61 cases, improved 110 cases, relapsed 10 cases. Curative effect was related to treatment times, cured and good effected 5 times 12.5 percent, 10 times 31 percent, 15 times 94 percent. A matched control group in 17 patients was treated by drug. The results: good effected 1 case, improved 13 cases, not effected 3 cases.

Scary gas: intravascular, intracranial, and intraspinal ectopic gas (part III).

PubMed

Sandstrom, Claire K; Osman, Sherif F; Linnau, Ken F

2017-08-01

While ectopic gas can be a sign of dangerous disease requiring immediate medical or surgical intervention, it can also be an incidental and benign finding. Intravenous gas and spinal vacuum gas are common and almost always benign. Intravascular gas is most often related to instrumentation and, if intraarticular, can cause end-organ ischemia; however, treatment is usually supportive. Pneumocephalus arises from a communication with paranasal sinuses or mastoids more often than from meningeal infection and can usually be managed nonoperatively. In part 3 of this series, the different causes of ectopic gas in the vessels, skull, and spine are reviewed, as are the imaging features that can help to narrow the differential diagnosis.

Donath-Landsteiner test

MedlinePlus

... and intravascular hemolytic anemias. In: Goldman L, Schafer AI, eds. Goldman's Cecil Medicine . 25th ed. ... Florida Cancer Specialists & Research Institute, Wellington, FL. Review provided by ...

Adenosine receptor agonist NECA increases cerebral extravasation of fluorescein and low molecular weight dextran independent of blood-brain barrier modulation

PubMed Central

Cheng, Chih-Chung; Yang, Ya Lan; Liao, Kate Hsiurong; Lai, Ted Weita

2016-01-01

Conventional methods for therapeutic blood-brain barrier (BBB) disruption facilitate drug delivery but are cumbersome to perform. A previous study demonstrated that adenosine receptor (AR) stimulation by 5′-N-ethylcarboxamide adenosine (NECA) increased the extravasation of intravascular tracers into the brain and proposed that AR agonism may be an effective method for therapeutic BBB disruption. We attempted to confirm the extravasation of tracers into the brain and also investigated tracer extravasation into peripheral organs and tracer retention in the blood. We found that NECA not only increased the extravasation of intravascular fluorescein and low molecular weight dextran into the brain of mice but also increased the concentrations of these tracers in the blood. In fact, the brain:blood ratio-normalized BBB permeability for either tracer is actually decreased by NECA administration. Elevated blood urea nitrogen levels in mice following NECA treatment suggested that renal function impairment was a probable cause of tracer retention. Therefore, NECA has almost no effect on the extravasation of intravascular Evans blue dye (EBD), an albumin-binding tracer with little renal clearance. Rather than inducing BBB disruption, our study demonstrated that NECA increased tracer extravasation into the brain by increasing the concentration gradient of the tracer across the BBB. PMID:27025761

Intravascular ultrasound catheter to enhance microbubble-based drug delivery via acoustic radiation force.

PubMed

Kilroy, Joseph P; Klibanov, Alexander L; Wamhoff, Brian R; Hossack, John A

2012-10-01

Previous research has demonstrated that acoustic radiation force enhances intravascular microbubble adhesion to blood vessels in the presence of flow for moleculartargeted ultrasound imaging and drug delivery. A prototype acoustic radiation force intravascular ultrasound (ARFIVUS) catheter was designed and fabricated to displace a microbubble contrast agent in flow representative of conditions encountered in the human carotid artery. The prototype ARFIVUS transducer was designed to match the resonance frequency of 1.4- to 2.6-μm-diameter microbubbles modeled by an experimentally verified 1-D microbubble acoustic radiation force translation model. The transducer element was an elongated Navy Type I (hard) lead zirconate titanate (PZT) ceramic designed to operate at 3 MHz. Fabricated devices operated with center frequencies of 3.3 and 3.6 MHz with -6-dB fractional bandwidths of 55% and 50%, respectively. Microbubble translation velocities as high as 0.86 m/s were measured using a high-speed streak camera when insonating with the ARFIVUS transducer. Finally, the prototype was used to displace microbubbles in a flow phantom while imaging with a commercial 45-MHz imaging IVUS transducer. A sustained increase of 31 dB in average video intensity was measured following insonation with the ARFIVUS, indicating microbubble accumulation resulting from the application of acoustic radiation force.

One-stage surgery for removal of intravascular leiomyomatosis extending to right ventricle.

PubMed

Chiang, Ching-Shu; Chen, Po-Lin; Kuo, Tzu-Ting; Chen, I-Ming; Wu, Nai-Yuan; Chang, Hsiao-Huang

2018-03-01

Intravascular leiomyomatosis (IVL) is a rare nonmalignant tumor that can be fatal if untreated. A 49-year-old nulliparous Asian woman who underwent hysterectomy and left salpingo-oophorectomy for multiple uterine leiomyomas 18 months prior presented complaining of intermittent palpitation and chest tightness for approximately 1 month. Echocardiography revealed a large mobile tumor mass extending from the inferior vena cava (IVC) to the right atrium that partially obstructed IVC flow and tricuspid inflow. Thoracicabdominopelvic computed tomography revealed a left adnexal tumor (4.8 × 2.5 cm) causing intravascular obstruction extending from the left internal iliac vein to the IVC, right atrium, and right ventricle. IVL with right heart involvement INTERVENTIONS:: Under cardiopulmonary bypass, a one-stage surgery combining sternotomy and laparotomy was performed. The tumor was approached and extracted via sternotomy, and tumor detachment and removal of residual tumors was accomplished via laparotomy. A firm, smooth, and regularly shape tumor 15.5 × 5.5 × 2.5 in size was completely removed and histopathologically confirmed as IVL. The patient tolerated the surgical procedure well and no postoperative complication was noted. We describe a one-stage surgical approach to completely remove an IVL extending to the right ventricle.

Adenosine receptor agonist NECA increases cerebral extravasation of fluorescein and low molecular weight dextran independent of blood-brain barrier modulation.

PubMed

Cheng, Chih-Chung; Yang, Ya Lan; Liao, Kate Hsiurong; Lai, Ted Weita

2016-03-30

Conventional methods for therapeutic blood-brain barrier (BBB) disruption facilitate drug delivery but are cumbersome to perform. A previous study demonstrated that adenosine receptor (AR) stimulation by 5'-N-ethylcarboxamide adenosine (NECA) increased the extravasation of intravascular tracers into the brain and proposed that AR agonism may be an effective method for therapeutic BBB disruption. We attempted to confirm the extravasation of tracers into the brain and also investigated tracer extravasation into peripheral organs and tracer retention in the blood. We found that NECA not only increased the extravasation of intravascular fluorescein and low molecular weight dextran into the brain of mice but also increased the concentrations of these tracers in the blood. In fact, the brain:blood ratio-normalized BBB permeability for either tracer is actually decreased by NECA administration. Elevated blood urea nitrogen levels in mice following NECA treatment suggested that renal function impairment was a probable cause of tracer retention. Therefore, NECA has almost no effect on the extravasation of intravascular Evans blue dye (EBD), an albumin-binding tracer with little renal clearance. Rather than inducing BBB disruption, our study demonstrated that NECA increased tracer extravasation into the brain by increasing the concentration gradient of the tracer across the BBB.

Erythrocytes are the major intravascular storage sites of nitrite in human blood

PubMed Central

Dejam, André; Hunter, Christian J.; Pelletier, Mildred M.; Hsu, Lewis L.; Machado, Roberto F.; Shiva, Sruti; Power, Gordon G.; Kelm, Malte; Gladwin, Mark T.; Schechter, Alan N.

2005-01-01

Plasma levels of nitrite ions have been used as an index of nitric oxide synthase (NOS) activity in vivo. Recent data suggest that nitrite is a potential intravascular repository for nitric oxide (NO), bioactivated by a nitrite reductase activity of deoxyhemoglobin. The precise levels and compartmentalization of nitrite within blood and erythrocytes have not been determined. Nitrite levels in whole blood and erythrocytes were determined using reductive chemiluminescence in conjunction with a ferricyanide-based hemoglobin oxidation assay to prevent nitrite destruction. This method yields sensitive and linear measurements of whole blood nitrite over 24 hours at room temperature. Nitrite levels measured in plasma, erythrocytes, and whole blood from 15 healthy volunteers were 121 plus or minus 9, 288 plus or minus 47, and 176 plus or minus 17 nM, indicating a surprisingly high concentration of nitrite within erythrocytes. The majority of nitrite in erythrocytes is located in the cytosol unbound to proteins. In humans, we found a significant artery-to-vein gradient of nitrite in whole blood and erythrocytes. Shear stress and acetylcholine-mediated stimulation of endothelial NOS significantly increased venous nitrite levels. These studies suggest a dynamic intravascular NO metabolism in which endothelial NOS-derived NO is stabilized as nitrite, transported by erythrocytes, and consumed during arterial-to-venous transit. (Blood. 2005;106:734-739) PMID:15774613

Passively Driven Probe Based on Miniaturized Propeller for Intravascular Optical Coherence Tomography.

PubMed

Lu, Yu; Li, Zhongliang; Nan, Nan; Bu, Yang; Liu, Xuebo; Xu, Xiangdong; Wang, Xuan; Sasaki, Osami; Wang, Xiangzhao

2018-03-26

Optical coherent tomography (OCT) has enabled clinical applications ranging from ophthalmology to cardiology that revolutionized in vivo medical diagnostics in the last few decades, and a variety of endoscopic probes have been developed in order to meet the needs of various endoscopic OCT imaging. We propose a passive driven intravascular optical coherent tomography (IV-OCT) probe in this paper. Instead of using any electrically driven scanning device, the probe makes use of the kinetic energy of the fluid that flushes away the blood during the intravascular optical coherence tomography imaging. The probe converts it into the rotational kinetic energy of the propeller, and the rotation of the rectangular prism mounted on the propeller shaft enables the scanning of the beam. The probe is low cost, and enables unobstructed stable circumferential scanning over 360 deg. The experimental results show that the probe scanning speed can exceed 100 rotations per second (rps). Spectral-domain OCT imaging of a phantom and porcine cardiac artery are demonstrated with axial resolution of 13.6 μm, lateral resolution of 22 μm, and sensitivity of 101.7 dB. We present technically the passively driven IV-OCT probe in full detail and discuss how to optimize the probe in further.

Pulsed liquid microjet for intravascular injection

NASA Astrophysics Data System (ADS)

Palanker, Daniel V.; Fletcher, Daniel A.; Miller, Jason; Huie, Philip; Marmor, Michael; Blumenkranz, Mark S.

2002-06-01

Occlusions of the retinal veins and arteries are associated with common diseases such as hypertension and arteriosclerosis and usually cause severe and irreversible loss of vision. Treatments for these vascular diseases have been unsatisfactory to date in part because of the difficulty of delivering thrombolytic drugs locally within the eye. In this article we describe a pulsed liquid microjet for minimally invasive intra-vascular drug delivery. The microjet is driven by a vapor bubble following an explosive evaporation of saline, produced by a microsecond-long electric discharge in front of the 25 micrometers electrode inside the micronozzle. Expansion of the transient vapor bubble produces a water jet with a diameter equal to the diameter of the nozzle, and with a velocity and duration that are controlled by the pulse energy. We found that fluid could be injected through the wall of a 60-micrometers -diameter artery in choriallantoic membrane using a 15-micrometers diameter liquid jet traveling at more than 60 m/s. Histological analysis of these arteries showed that the width of the perforation is limited to the diameter of the micronozzle, and the penetration depth of the jet is controlled by the discharge energy. The pulsed liquid microjet offers a promising technique for precise and needle-free intravascular delivery of thrombolytic drugs for localized treatment of retinal vascular occlusions.

Adaptive windowing in contrast-enhanced intravascular ultrasound imaging

PubMed Central

Lindsey, Brooks D.; Martin, K. Heath; Jiang, Xiaoning; Dayton, Paul A.

2016-01-01

Intravascular ultrasound (IVUS) is one of the most commonly-used interventional imaging techniques and has seen recent innovations which attempt to characterize the risk posed by atherosclerotic plaques. One such development is the use of microbubble contrast agents to image vasa vasorum, fine vessels which supply oxygen and nutrients to the walls of coronary arteries and typically have diameters less than 200 µm. The degree of vasa vasorum neovascularization within plaques is positively correlated with plaque vulnerability. Having recently presented a prototype dual-frequency transducer for contrast agent-specific intravascular imaging, here we describe signal processing approaches based on minimum variance (MV) beamforming and the phase coherence factor (PCF) for improving the spatial resolution and contrast-to-tissue ratio (CTR) in IVUS imaging. These approaches are examined through simulations, phantom studies, ex vivo studies in porcine arteries, and in vivo studies in chicken embryos. In phantom studies, PCF processing improved CTR by a mean of 4.2 dB, while combined MV and PCF processing improved spatial resolution by 41.7%. Improvements of 2.2 dB in CTR and 37.2% in resolution were observed in vivo. Applying these processing strategies can enhance image quality in conventional B-mode IVUS or in contrast-enhanced IVUS, where signal-to-noise ratio is relatively low and resolution is at a premium. PMID:27161022

Three-dimensional registration of intravascular optical coherence tomography and cryo-image volumes for microscopic-resolution validation.

PubMed

Prabhu, David; Mehanna, Emile; Gargesha, Madhusudhana; Brandt, Eric; Wen, Di; van Ditzhuijzen, Nienke S; Chamie, Daniel; Yamamoto, Hirosada; Fujino, Yusuke; Alian, Ali; Patel, Jaymin; Costa, Marco; Bezerra, Hiram G; Wilson, David L

2016-04-01

Evidence suggests high-resolution, high-contrast, [Formula: see text] intravascular optical coherence tomography (IVOCT) can distinguish plaque types, but further validation is needed, especially for automated plaque characterization. We developed experimental and three-dimensional (3-D) registration methods to provide validation of IVOCT pullback volumes using microscopic, color, and fluorescent cryo-image volumes with optional registered cryo-histology. A specialized registration method matched IVOCT pullback images acquired in the catheter reference frame to a true 3-D cryo-image volume. Briefly, an 11-parameter registration model including a polynomial virtual catheter was initialized within the cryo-image volume, and perpendicular images were extracted, mimicking IVOCT image acquisition. Virtual catheter parameters were optimized to maximize cryo and IVOCT lumen overlap. Multiple assessments suggested that the registration error was better than the [Formula: see text] spacing between IVOCT image frames. Tests on a digital synthetic phantom gave a registration error of only [Formula: see text] (signed distance). Visual assessment of randomly presented nearby frames suggested registration accuracy within 1 IVOCT frame interval ([Formula: see text]). This would eliminate potential misinterpretations confronted by the typical histological approaches to validation, with estimated 1-mm errors. The method can be used to create annotated datasets and automated plaque classification methods and can be extended to other intravascular imaging modalities.

Podoplanin-Fc reduces lymphatic vessel formation in vitro and in vivo and causes disseminated intravascular coagulation when transgenically expressed in the skin

PubMed Central

Cueni, Leah N.; Chen, Lu; Zhang, Hui; Marino, Daniela; Huggenberger, Reto; Alitalo, Annamari; Bianchi, Roberta

2010-01-01

Podoplanin is a small transmembrane protein required for development and function of the lymphatic vascular system. To investigate the effects of interfering with its function, we produced an Fc fusion protein of its ectodomain. We found that podoplanin-Fc inhibited several functions of cultured lymphatic endothelial cells and also specifically suppressed lymphatic vessel growth, but not blood vessel growth, in mouse embryoid bodies in vitro and in mouse corneas in vivo. Using a keratin 14 expression cassette, we created transgenic mice that overexpressed podoplanin-Fc in the skin. No obvious outward phenotype was identified in these mice, but surprisingly, podoplanin-Fc—although produced specifically in the skin—entered the blood circulation and induced disseminated intravascular coagulation, characterized by microthrombi in most organs and by thrombocytopenia, occasionally leading to fatal hemorrhage. These findings reveal an important role of podoplanin in lymphatic vessel formation and indicate the potential of podoplanin-Fc as an inhibitor of lymphangiogenesis. These results also demonstrate the ability of podoplanin to induce platelet aggregation in vivo, which likely represents a major function of lymphatic endothelium. Finally, keratin 14 podoplanin-Fc mice represent a novel genetic animal model of disseminated intravascular coagulation. PMID:20716773

Subhuman Primate Pregnancy Complicated by Streptozotocin-Induced Diabetes Mellitus

PubMed Central

Mintz, Daniel H.; Chez, Ronald A.; Hutchinson, Donald L.

1972-01-01

Polydipsia, polyuria, polyphagia, and glucosuria followed the administration of streptozotocin to 6 nonpregnant and 15 pregnant monkeys (Macaca mulatta) in the first trimester of pregnancy. The diabetogenic action of the drug was also reflected in an induced but variable deterioration in maternal intravenous glucose tolerance and a marked attenuation of maternal plasma insulin responsiveness to intravenous glycemic stimuli. The products of conception were examined in 29 pregnancies. The neonates and the placentas of the streptozotocin-treated pregnant animals were significantly heavier than average for the period of gestation, polyhydramnios was consistently present, and there was an increase in the incidence of third trimester stillbirths. The fetal and maternal plasma glucose, insulin, and growth hormone concentrations were examined after the intravascular administration of glucose or a solution of mixed amino acids to the fetus in the third trimester. The neonatal plasma responses to similar insulinogenic stimuli were also examined. Fetal and neonatal base line plasma insulin concentrations were significantly elevated compared to those of the controls. The administration of intravascular glucose to the fetus, mother, or neonate was associated with a prompt 2-to 5-fold increase in fetal or neonatal plasma insulin concentrations. These findings contrast to the unresponsiveness of the pancreatic islet tissue we reported in normal subhuman primate pregnancy. The intravascular infusion of a relatively low concentration of mixed amino acids (2 mg/min) to the conceptii from the streptozotocin-treated pregnancies was associated with an elevation in fetal and neonatal plasma insulin levels, whereas normal monkey fetuses and neonates required a 10-fold greater concentration of amino acids in the infusate for similar responses. The induced hyperaminoacidemia or hyperglycemia did not consistently alter plasma growth hormone concentrations in the conceptii from normal or streptozotocin-treated pregnancies. These data provide evidence that maternal glucose intolerance during pregnancy is associated with enhanced fetal and neonatal pancreatic islet cell responsiveness to glucose and mixed amino acids. Although the specific mechanism(s) that alters both the sensitivity and responsiveness of the normal pancreatic fetal islet to insulinogenic stimuli remains unclear, the data do indicate that insulin-dependent maternal hyperglycemia and hyperaminoacidemia, separately or in combination could contribute to the fetal hyperinsulinemia of pregnancies complicated by diabetes mellitus. Moreover, the overall experiences with these streptozotocin-treated animals suggest that a subhuman primate model may be available to examine directly the antenatal pathophysiology of abnormal carbohydrate metabolism. PMID:4259254

Plaque Structural Stress Estimations Improve Prediction of Future Major Adverse Cardiovascular Events After Intracoronary Imaging.

PubMed

Brown, Adam J; Teng, Zhongzhao; Calvert, Patrick A; Rajani, Nikil K; Hennessy, Orla; Nerlekar, Nitesh; Obaid, Daniel R; Costopoulos, Charis; Huang, Yuan; Hoole, Stephen P; Goddard, Martin; West, Nick E J; Gillard, Jonathan H; Bennett, Martin R

2016-06-01

Although plaque rupture is responsible for most myocardial infarctions, few high-risk plaques identified by intracoronary imaging actually result in future major adverse cardiovascular events (MACE). Nonimaging markers of individual plaque behavior are therefore required. Rupture occurs when plaque structural stress (PSS) exceeds material strength. We therefore assessed whether PSS could predict future MACE in high-risk nonculprit lesions identified on virtual-histology intravascular ultrasound. Baseline nonculprit lesion features associated with MACE during long-term follow-up (median: 1115 days) were determined in 170 patients undergoing 3-vessel virtual-histology intravascular ultrasound. MACE was associated with plaque burden ≥70% (hazard ratio: 8.6; 95% confidence interval, 2.5-30.6; P<0.001) and minimal luminal area ≤4 mm(2) (hazard ratio: 6.6; 95% confidence interval, 2.1-20.1; P=0.036), although absolute event rates for high-risk lesions remained <10%. PSS derived from virtual-histology intravascular ultrasound was subsequently estimated in nonculprit lesions responsible for MACE (n=22) versus matched control lesions (n=22). PSS showed marked heterogeneity across and between similar lesions but was significantly increased in MACE lesions at high-risk regions, including plaque burden ≥70% (13.9±11.5 versus 10.2±4.7; P<0.001) and thin-cap fibroatheroma (14.0±8.9 versus 11.6±4.5; P=0.02). Furthermore, PSS improved the ability of virtual-histology intravascular ultrasound to predict MACE in plaques with plaque burden ≥70% (adjusted log-rank, P=0.003) and minimal luminal area ≤4 mm(2) (P=0.002). Plaques responsible for MACE had larger superficial calcium inclusions, which acted to increase PSS (P<0.05). Baseline PSS is increased in plaques responsible for MACE and improves the ability of intracoronary imaging to predict events. Biomechanical modeling may complement plaque imaging for risk stratification of coronary nonculprit lesions. © 2016 American Heart Association, Inc.

Compensation of spectral artifacts in dual-modality intravascular optical coherence tomography and near-infrared spectroscopy (Conference Presentation)

NASA Astrophysics Data System (ADS)

Fard, Ali M.; Gardecki, Joseph A.; Ughi, Giovanni J.; Hyun, Chulho; Tearney, Guillermo J.

2016-02-01

Intravascular optical coherence tomography (OCT) is a high-resolution catheter-based imaging method that provides three-dimensional microscopic images of coronary artery in vivo, facilitating coronary artery disease treatment decisions based on detailed morphology. Near-infrared spectroscopy (NIRS) has proven to be a powerful tool for identification of lipid-rich plaques inside the coronary walls. We have recently demonstrated a dual-modality intravascular imaging technology that integrates OCT and NIRS into one imaging catheter using a two-fiber arrangement and a custom-made dual-channel fiber rotary junction. It therefore enables simultaneous acquisition of microstructural and composition information at 100 frames/second for improved diagnosis of coronary lesions. The dual-modality OCT-NIRS system employs a single wavelength-swept light source for both OCT and NIRS modalities. It subsequently uses a high-speed photoreceiver to detect the NIRS spectrum in the time domain. Although use of one light source greatly simplifies the system configuration, such light source exhibits pulse-to-pulse wavelength and intensity variation due to mechanical scanning of the wavelength. This can be in particular problematic for NIRS modality and sacrifices the reliability of the acquired spectra. In order to address this challenge, here we developed a robust data acquisition and processing method that compensates for the spectral variations of the wavelength-swept light source. The proposed method extracts the properties of the light source, i.e., variation period and amplitude from a reference spectrum and subsequently calibrates the NIRS datasets. We have applied this method on datasets obtained from cadaver human coronary arteries using a polygon-scanning (1230-1350nm) OCT system, operating at 100,000 sweeps per second. The results suggest that our algorithm accurately and robustly compensates the spectral variations and visualizes the dual-modality OCT-NIRS images. These findings are therefore crucial for the practical application and clinical translation of dual-modality intravascular OCT-NIRS imaging when the same swept sources are used for both OCT and spectroscopy.

Resistant Hypertension On Treatment (ResHypOT): sequential nephron blockade compared to dual blockade of the renin-angiotensin-aldosterone system plus bisoprolol in the treatment of resistant arterial hypertension - study protocol for a randomized controlled trial.

PubMed

Cestário, Elizabeth do Espirito Santo; Fernandes, Letícia Aparecida Barufi; Giollo-Júnior, Luiz Tadeu; Uyemura, Jéssica Rodrigues Roma; Matarucco, Camila Suemi Sato; Landim, Manoel Idelfonso Paz; Cosenso-Martin, Luciana Neves; Tácito, Lúcia Helena Bonalume; Moreno, Heitor; Vilela-Martin, José Fernando; Yugar-Toledo, Juan Carlos

2018-02-12

Resistant hypertension is characterized when the blood pressure (BP) remains above the recommended goal after taking three antihypertensive drugs with synergistic actions at their maximum recommended tolerated doses, preferably including a diuretic. Identifying the contribution of intravascular volume and serum renin in maintaining BP levels could help tailor more effective hypertension treatment, whether acting on the control of intravascular volume or sodium balance, or acting on the effects of the renin-angiotensin-aldosterone system (RAAS) on the kidney. This is a randomized, open-label, clinical trial is designed to compare sequential nephron blockade and its contribution to the intravascular volume component with dual blockade of the RAAS plus bisoprolol and the importance of serum renin in maintaining BP levels. The trial has two arms: sequential nephron blockade versus dual blockade of the RAAS (with an angiotensin converting enzyme (ACE) inhibitor plus a beta-blocker) both added-on to a thiazide diuretic, a calcium-channel blocker and an angiotensin receptor-1 blocker (ARB). Sequential nephron blockade consists in a progressive increase in sodium depletion using a thiazide diuretic, an aldosterone-receptor blocker, furosemide and, finally, amiloride. On the other hand, the dual blockade of the RAAS consists of the progressive addition of an ACE inhibitor until the maximum dose and then the administration of a beta-blocker until the maximum dose. The primary outcomes will be reductions in the systolic BP, diastolic BP, mean BP and pulse pressure (PP) after 20 weeks of treatment. The secondary outcomes will evaluate treatment safety and tolerability, biochemical changes, evaluation of renal function and recognition of hypotension (ambulatory BP monitoring (ABPM)). The sample size was calculated assuming an alpha error of 5% to reject the null hypothesis with a statistical power of 80% giving a total of 40 individuals per group. In recent years, the cost of resistant hypertension (RH) treatment has increased. Thus, identifying the contribution of intravascular volume and serum renin in maintaining BP levels could help tailor more effective hypertension treatment, whether by acting on the control of intravascular volume or sodium balance, or by acting on the effects of the RAAS on the kidney. Sequential Nephron Blockade vs. Dual Blockade Renin-angiotensin System + Bisoprolol in Resistant Arterial Hypertension (ResHypOT). ClinicalTrials.gov, ID: NCT02832973 . Registered on 14 July 2016. First received: 12 June 2016. Last updated: 18 July 2016.

[Vasopressin intravenous infusion causes dose dependent adverse cardiovascular effects in anesthetized dogs.

PubMed

Martins, Luiz Cláudio; Sabha, Maricene; Paganelli, Maria Ondina; Coelho, Otávio Rizzi; Ferreira-Melo, Silvia Elaine; Moreira, Marcos Mello; Cavalho, Adriana Camargo de; Araujo, Sebastião; Moreno Junior, Heitor

2010-01-15

BACKGROUND: Arginine vasopressin (AVP) has been broadly used in the management of vasodilatory shock. However, there are many concerns regarding its clinical use, especially in high doses, as it can be associated with adverse cardiovascular events. OBJECTIVE: To investigate the cardiovascular effects of AVP in continuous IV infusion on hemodynamic parameters in dogs. METHODS: Sixteen healthy mongrel dogs, anesthetized with pentobarbital were intravascularly catheterized, and randomly assigned to: control (saline-placebo; n=8) and AVP (n=8) groups. The study group was infused with AVP for three consecutive 10-minute periods at logarithmically increasing doses (0.01; 0.1 and 1.0U/kg/min), at them 20-min intervals. Heart rate (HR) and intravascular pressures were continuously recorded. Cardiac output was measured by the thermodilution method. RESULTS: No significant hemodynamic effects were observed during 0.01U/kg/min of AVP infusion, but at higher doses (0.1 and 1.0U/kg/min) a progressive increase in mean arterial pressure (MAP) and systemic vascular resistance index (SVRI) were observed, with a significant decrease in HR and the cardiac index (CI). A significant increase in the pulmonary vascular resistance index (PVRI) was also observed with the 1.0U/kg/min dose, mainly due to the decrease in the CI. CONCLUSION: AVP, when administered at doses between 0.1 and 1.0U/kg/min, induced significant increases in MAP and SVRI, with negative inotropic and chronotropic effects in healthy animals. Although these doses are ten to thousand times greater than those routinely used for the management of vasodilatory shock, our data confirm that AVP might be used carefully and under strict hemodynamic monitoring in clinical practice, especially if doses higher than 0.01 U/kg/min are needed. Martins, LC et al.

The Use of Convection-Enhanced Delivery with Liposomal Toxins in Neurooncology

PubMed Central

Fiandaca, Massimo S.; Berger, Mitchel S.; Bankiewicz, Krystof S.

2011-01-01

Liposomes have long been effective delivery vehicles for transport of toxins to peripheral cancers. The combination of convection-enhanced delivery (CED) with liposomal toxins was originally proposed to circumvent the limited delivery of intravascular liposomes to the central nervous system (CNS) due to the blood-brain-barrier (BBB). CED offers markedly improved distribution of infused therapeutics within the CNS compared to direct injection or via drug eluting polymers, both of which depend on diffusion for parenchymal distribution. This review examines the basis for improved delivery of liposomal toxins via CED within the CNS, and discusses preclinical and clinical experience with these therapeutic techniques. How CED and liposomal technologies may influence future neurooncologic treatments are also considered. PMID:22069714

Intravascular Ultrasound

MedlinePlus

... Daily Conferences Fellowships and Residencies School of Perfusion Technology Education Resources Library & Learning Resource Center CME Resources THI Journal THI Cardiac Society Save the Date: International Symposium on Cardiovascular Regenerative ...

Intravascular ultrasound guided directional atherectomy versus directional atherectomy guided by angiography for the treatment of femoropopliteal in-stent restenosis

PubMed Central

Krishnan, Prakash; Tarricone, Arthur; K-Raman, Purushothaman; Majeed, Farhan; Kapur, Vishal; Gujja, Karthik; Wiley, Jose; Vasquez, Miguel; Lascano, Rheoneil A.; Quiles, Katherine G.; Distin, Tashanne; Fontenelle, Ran; Atallah-Lajam, Farah; Kini, Annapoorna; Sharma, Samin

2017-01-01

Background: The aim of this study was to compare 1-year outcomes for patients with femoropopliteal in-stent restenosis using directional atherectomy guided by intravascular ultrasound (IVUS) versus directional atherectomy guided by angiography. Methods and results: This was a retrospective analysis for patients with femoropopliteal in-stent restenosis treated with IVUS-guided directional atherectomy versus directional atherectomy guided by angiography from a single center between March 2012 and February 2016. Clinically driven target lesion revascularization was the primary endpoint and was evaluated through medical chart review as well as phone call follow up. Conclusions: Directional atherectomy guided by IVUS reduces clinically driven target lesion revascularization for patients with femoropopliteal in-stent restenosis. PMID:29265002

Penile necrosis secondary to purpura fulminans: a case report and review of literature

PubMed Central

Cheon, Paul M.; Kassam, Javeed; Seal, Alexander E.; Kavanagh, Alexander G.

2017-01-01

Abstract We report the case of a 60-year-old Hispanic male with widespread necrotic purpuric lesions involving the penile, suprapubic, inguinal and hip dermis due to purpura fulminans. Purpura fulminans describes a rare syndrome involving intravascular thrombosis and hemorrhagic infarction of the skin; this rapidly progressing syndrome features vascular collapse and disseminated intravascular coagulation. This patient’s penile necrosis involved the majority of the penile shaft and glans penis, and ultimately required partial glansectomy and repeated debridement for treatment. Subsequently, full thickness skin grafting was completed for reconstruction with good effect. While reports of penile necrosis secondary to various causes are documented in the literature, no prior reports describe penile necrosis secondary to purpura fulminans. PMID:28479975

Spectrum of purpura fulminans: report of three classical prototypes and review of management strategies.

PubMed

Talwar, Ankur; Kumar, Sharath; Gopal, M G; Nandini, A S

2012-01-01

Purpura fulminans is a rare syndrome of intravascular thrombosis and hemorrhagic infarction of the skin that is rapidly progressive and is accompanied by vascular collapse and disseminated intravascular coagulation. It usually occurs in children, but this syndrome has also been noted in adults. The three forms of this disease are classified by the triggering mechanisms. We describe three classical cases of purpura fulminans of the three classical prototypes treated at our center and their varied clinical outcomes. We also describe a case of acute infectious purpura fulminans secondary to systemic leptospirosis which to our best knowledge is the first reported case in world literature. The various treatment options for purpura fulminans have also been reviewed.

A new method for real-time co-registration of 3D coronary angiography and intravascular ultrasound or optical coherence tomography.

PubMed

Carlier, Stéphane; Didday, Rich; Slots, Tristan; Kayaert, Peter; Sonck, Jeroen; El-Mourad, Mike; Preumont, Nicolas; Schoors, Dany; Van Camp, Guy

2014-06-01

We present a new clinically practical method for online co-registration of 3D quantitative coronary angiography (QCA) and intravascular ultrasound (IVUS) or optical coherence tomography (OCT). The workflow is based on two modified commercially available software packages. Reconstruction steps are explained and compared to previously available methods. The feasibility for different clinical scenarios is illustrated. The co-registration appears accurate, robust and induced a minimal delay on the normal cath lab activities. This new method is based on the 3D angiographic reconstruction of the catheter path and does not require operator's identification of landmarks to establish the image synchronization. Copyright © 2014 Elsevier Inc. All rights reserved.

Coronary artery aneurysm after stent implantation: acute and long-term results after percutaneous treatment with a stent graft.

PubMed

Rubartelli, Paolo; Terzi, Giacomo; Borgo, Lorenzo; Giachero, Corinna

2002-03-01

A patient with unstable angina was treated with elective Palmaz-Schatz stent implantation on a focal stenosis of the left circumflex artery. One year later, a large (13 mm in diameter) coronary artery aneurysm was diagnosed at angiography in the stented site. Intravascular ultrasound examination confirmed the presence of a true aneurysm located at the proximal end of the stent. The aneurysm was successfully treated with a Jostent Graft (Jomed Implantate) consisting of two slotted tube stainless steel stents supporting a polytetrafluoroethylene tube. The stent graft was implanted under intravascular ultrasound guidance. The 18-month angiographic follow-up showed good patency of the stent graft and complete exclusion of the aneurysm.

Extravasation injuries in adults.

PubMed

Al-Benna, S; O'Boyle, C; Holley, J

2013-01-01

Insertion of an intravascular catheter is one of the most common invasive procedures in hospitals worldwide. These intravascular lines are crucial in resuscitation, allow vital medication to be administered, and can be used to monitor the patients' real-time vital parameters. There is, however, growing recognition of potential risks to life and limb associated with their use. Medical literature is now replete with isolated case reports of complications succinctly described by Garden and Laussen (2004) as "An unending supply of "unusual" complications from central venous catheters." This paper reviews complications of venous and arterial catheters and discusses treatment approaches and methods to prevent complications, based on current evidence and endeavours to provide information and guidance that will enable practitioners to prevent, recognise, and successfully treat extravasation injuries in adults.

Disseminated intravascular coagulation in paediatrics.

PubMed

Rajagopal, Revathi; Thachil, Jecko; Monagle, Paul

2017-02-01

Disseminated intravascular coagulation (DIC) in paediatrics is associated with significant morbidity and mortality. Although there have been several recent advances in the pathophysiology of DIC, most of these studies were done in adults. Since the haemostatic system is very different in early life and changes dramatically with age, creating a variety of challenges for the clinician, delay in the diagnosis of DIC can happen until overt DIC is evident. In this review article, we report the aetiology, pathophysiology, clinical manifestations, diagnostic tests and a management algorithm to guide paediatricians when treating patients with DIC. 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/.

[Pulmonary thromboendarterectomy].

PubMed

Lausberg, H F; Tscholl, D; Schäfers, H-J

2004-08-01

Chronic thromboembolic pulmonary hypertension with concomitant right heart failure may develop as a sequela of acute pulmonary embolism with organization instead of thrombolysis of intravascular clots. Medical therapy aims at prevention of recurrent embolism by anticoagulation and vascular remodelling using vasodilator therapy. Lung transplantation or combined heart-lung transplantation is associated with unsatisfactory long-term results and comorbidity and therefore remains justified only in selected patients. Pulmonary thromboendarterectomy allows specific treatment of intravascular obstruction. This closed endarterectomy of the pulmonary arteries requires deep hypothermic circulatory arrest and can be performed with a perioperative mortality of less than 10%. The procedure significantly decreases pulmonary vascular resistance and often normalizes pulmonary hemodynamics and gas exchange. Postoperatively the patients' clinical condition improves and the majority have normal exercise capacity and activity.

Bilateral shotgun pellet pulmonary emboli

PubMed Central

Huebner, Stephen; Ali, Sayed

2012-01-01

Intravascular migration of bullets and other foreign bodies is a rare but known complication of penetrating trauma. Missile embolization can represent a diagnostic challenge because it may present in various and unexpected ways. We present the case of a 54-year-old female who sustained shotgun pellet emboli to the pulmonary arteries following a left upper extremity gunshot wound and related vascular surgery. The case illustrates bilateral embolization, and the embolic events occurred following surgery. Embolization should be considered in evaluating patients with gunshot wounds, particularly if there are anomalous symptoms or the projectile is not found in the original, or expected, location. Close attention to the location of the foreign bodies on serial radiographs may reveal the diagnosis of intravascular embolization. PMID:22690290

Single Center Experience with the AngioVac Aspiration System

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

Salsamendi, Jason, E-mail: jsalsamendi@med.miami.edu; Doshi, Mehul, E-mail: mdoshi@med.miami.edu; Bhatia, Shivank, E-mail: sbhatia1@med.miami.edu

2015-08-15

PurposeThe AngioVac catheter system is a mechanical suction device designed for removal of intravascular material using extracorporeal veno-venous bypass circuit. The purpose of this study is to present the outcomes in patients treated with the AngioVac aspiration system and to discuss its efficacy in different vascular beds.Materials and MethodsA retrospectively review was performed of seven patients treated with AngioVac between October 2013 and December 2014. In 6/7 cases, the AngioVac cannula was inserted percutaneously and the patient was placed on veno-venous bypass. In one of the cases, the cannula was inserted directly into the Fontan circuit after sternotomy and themore » patient was maintained on cardiopulmonary bypass. Thrombus location included iliocaval (2), SVC (1), pulmonary arteries (1), Fontan circuit and Glenn shunt with pulmonary artery extension (1), right atrium (1), and IVC with renal vein extension (1).ResultsThe majority of thrombus (50–95 %) was removed in 5/7 cases, and partial thrombus removal (<50 %) was confirmed in 2/7 cases. Mean follow-up was 205 days (range 64–403 days). All patients were alive at latest follow-up. Minor complications included three neck hematomas in two total patients. No major complications occurred.ConclusionAngioVac is a useful tool for acute thrombus removal in the large vessels. The setup and substantial cost may limit its application in straightforward cases. More studies are needed to establish the utility of AngioVac in treatment of intravascular and intracardiac material.« less

Role of particle size, shape, and stiffness in design of intravascular drug delivery systems: insights from computations, experiments, and nature.

PubMed

Sen Gupta, Anirban

2016-01-01

Packaging of drug molecules within microparticles and nanoparticles has become an important strategy in intravascular drug delivery, where the particles are designed to protect the drugs from plasma effects, increase drug residence time in circulation, and often facilitate drug delivery specifically at disease sites. To this end, over the past few decades, interdisciplinary research has focused on developing biocompatible materials for particle fabrication, technologies for particle manufacture, drug formulation within the particles for efficient loading, and controlled release and refinement of particle surface chemistries to render selectivity toward disease site for site-selective action. Majority of the particle systems developed for such purposes are spherical nano and microparticles and they have had low-to-moderate success in clinical translation. To refine the design of delivery systems for enhanced performance, in recent years, researchers have started focusing on the physicomechanical aspects of carrier particles, especially their shape, size, and stiffness, as new design parameters. Recent computational modeling studies, as well as, experimental studies using microfluidic devices are indicating that these design parameters greatly influence the particles' behavior in hemodynamic circulation, as well as cell-particle interactions for targeted payload delivery. Certain cellular components of circulation are also providing interesting natural cues for refining the design of drug carrier systems. Based on such findings, new benefits and challenges are being realized for the next generation of drug carriers. The current article will provide a comprehensive review of these findings and discuss the emerging design paradigm of incorporating physicomechanical components in fabrication of particulate drug delivery systems. © 2015 Wiley Periodicals, Inc.

Performance analysis of a miniature turbine generator for intracorporeal energy harvesting.

PubMed

Pfenniger, Alois; Vogel, Rolf; Koch, Volker M; Jonsson, Magnus

2014-05-01

Replacement intervals of implantable medical devices are commonly dictated by battery life. Therefore, intracorporeal energy harvesting has the potential to reduce the number of surgical interventions by extending the life cycle of active devices. Given the accumulated experience with intravascular devices such as stents, heart valves, and cardiac assist devices, the idea to harvest a small fraction of the hydraulic energy available in the cardiovascular circulation is revisited. The aim of this article is to explore the technical feasibility of harvesting 1 mW electric power using a miniature hydrodynamic turbine powered by about 1% of the cardiac output flow in a peripheral artery. To this end, numerical modelling of the fluid mechanics and experimental verification of the overall performance of a 1:1 scale friction turbine are performed in vitro. The numerical flow model is validated for a range of turbine configurations and flow conditions (up to 250 mL/min) in terms of hydromechanic efficiency; up to 15% could be achieved with the nonoptimized configurations of the study. Although this article does not entail the clinical feasibility of intravascular turbines in terms of hemocompatibility and impact on the circulatory system, the numerical model does provide first estimates of the mechanical shear forces relevant to blood trauma and platelet activation. It is concluded that the time-integrated shear stress exposure is significantly lower than in cardiac assist devices due to lower flow velocities and predominantly laminar flow. Copyright © 2014 International Center for Artificial Organs and Transplantation and Wiley Periodicals, Inc.

Ocular Pain and Impending Blindness During Facial Cosmetic Injections: Is Your Office Prepared?

PubMed

Prado, Giselle; Rodríguez-Feliz, Jose

2017-02-01

Soft tissue filler injections are the second most common non-surgical procedure performed by the plastic surgeon. Embolization of intravascular material after facial injection is a rare but terrifying outcome due to the high likelihood of long-term sequela such as blindness and cerebrovascular accident. The literature is replete with examples of permanent blindness caused by injection with autologous fat, soft tissue fillers such as hyaluronic acid, PLLA, calcium hydroxyl-apatite, and even corticosteroid suspensions. However, missing from the discussion is an effective treatment algorithm that can be quickly and safely followed by injecting physicians in the case of an intravascular injection with impending blindness. In this report, we present the case of a 64-year-old woman who suffered from blindness and hemiparesis after facial cosmetic injections performed by a family physician. We use this case to create awareness that this complication has become more common as the number of injectors and patients seeking these treatments have increased exponentially over the past few years. We share in this study our experience with the incorporation of a "blindness safety kit" in each of our offices to promptly initiate treatment in someone with embolization and impending blindness. The kit contains a step-by-step protocol to follow in the event of arterial embolization of filler material associated with ocular pain and impending loss of vision. This journal requires that authors assign a level of evidence to each article. For a full description of these Evidence-Based Medicine ratings, please refer to the Table of Contents or the online Instructions to Authors www.springer.com/00266 .

Monolithic CMUT-on-CMOS integration for intravascular ultrasound applications.

PubMed

Zahorian, Jaime; Hochman, Michael; Xu, Toby; Satir, Sarp; Gurun, Gokce; Karaman, Mustafa; Degertekin, F Levent

2011-12-01

One of the most important promises of capacitive micromachined ultrasonic transducer (CMUT) technology is integration with electronics. This approach is required to minimize the parasitic capacitances in the receive mode, especially in catheter-based volumetric imaging arrays, for which the elements must be small. Furthermore, optimization of the available silicon area and minimized number of connections occurs when the CMUTs are fabricated directly above the associated electronics. Here, we describe successful fabrication and performance evaluation of CMUT arrays for intravascular imaging on custom-designed CMOS receiver electronics from a commercial IC foundry. The CMUT-on-CMOS process starts with surface isolation and mechanical planarization of the CMOS electronics to reduce topography. The rest of the CMUT fabrication is achieved by modifying a low-temperature micromachining process through the addition of a single mask and developing a dry etching step to produce sloped sidewalls for simple and reliable CMUT-to-CMOS interconnection. This CMUT-to-CMOS interconnect method reduced the parasitic capacitance by a factor of 200 when compared with a standard wire-bonding method. Characterization experiments indicate that the CMUT-on-CMOS elements are uniform in frequency response and are similar to CMUTs simultaneously fabricated on standard silicon wafers without electronics integration. Ex- periments on a 1.6-mm-diameter dual-ring CMUT array with a center frequency of 15 MHz show that both the CMUTs and the integrated CMOS electronics are fully functional. The SNR measurements indicate that the performance is adequate for imaging chronic total occlusions located 1 cm from the CMUT array.

Microminiaturized minimally invasive intravascular micro-mechanical systems powered and controlled via fiber-optic cable

DOEpatents

Fitch, Joseph P.; Hagans, Karla; Clough, Robert; Matthews, Dennis L.; Lee, Abraham P.; Krulevitch, Peter A.; Benett, William J.; Da Silva, Luiz; Celliers, Peter M.

1998-01-01

A micro-mechanical system for medical procedures is constructed in the basic form of a catheter having a distal end for insertion into and manipulation within a body and a near end providing for a user to control the manipulation of the distal end within the body. A fiberoptic cable is disposed within the catheter and having a distal end proximate to the distal end of the catheter and a near end for external coupling of laser light energy. A microgripper is attached to the distal end of the catheter and providing for the gripping or releasing of an object within the body. A laser-light-to-mechanical-power converter is connected to receive laser light from the distal end of the fiberoptic cable and connected to mechanically actuate the microgripper.

[Facial mucormycosis: observations from three cases].

PubMed

Sellami-Boudawara, T; Gouiaa, N; Charfeddine, I; Abdelmoula, M; Drira, M; Jlidi, R

2002-12-01

The mucormycosis is a rare opportunistic invasive infection caused by fungi of the order Mucorales and characterized by vascular invasion and tissue necrosis. It affects generally the subjects with altered natural resistances, particularly the diabetics patients. The cerebro-rhino-orbital region is the most common site. The clinical signs depend on the intra-tissular and intra-vascular evolution of the fungi. The diagnosis of this disease is asserted by the mycological and anatomo-pathological exams. The treatment is based on the antifungic and the surgical excision of necrotic tissues. We report three observations: one man (42 years) and two women (59 and 60 years). Diabetes was found in two cases. The diagnosis was in every case anatomo-pathologic. Our objective was to study the epidemiological and clinico-pathologic aspects of this serious affection and to discuss its prognosis.

Microminiaturized minimally invasive intravascular micro-mechanical systems powered and controlled via fiber-optic cable

DOEpatents

Fitch, J.P.; Hagans, K.; Clough, R.; Matthews, D.L.; Lee, A.P.; Krulevitch, P.A.; Benett, W.J.; Silva, L. Da; Celliers, P.M.

1998-03-03

A micro-mechanical system for medical procedures is constructed in the basic form of a catheter having a distal end for insertion into and manipulation within a body and a near end providing for a user to control the manipulation of the distal end within the body. A fiber-optic cable is disposed within the catheter and having a distal end proximate to the distal end of the catheter and a near end for external coupling of laser light energy. A microgripper is attached to the distal end of the catheter and providing for the gripping or releasing of an object within the body. A laser-light-to-mechanical-power converter is connected to receive laser light from the distal end of the fiber-optic cable and connected to mechanically actuate the microgripper. 22 figs.

21 CFR 864.7340 - Fibrinogen determination system.

Code of Federal Regulations, 2010 CFR

2010-04-01

... disseminated intravascular coagulation (nonlocalized clotting within the blood vessels) and primary fibrinolysis (the dissolution of fibrin in a blood clot). (b) Classification. Class II (performance standards...

21 CFR 864.7340 - Fibrinogen determination system.

Code of Federal Regulations, 2012 CFR

2012-04-01

... disseminated intravascular coagulation (nonlocalized clotting within the blood vessels) and primary fibrinolysis (the dissolution of fibrin in a blood clot). (b) Classification. Class II (performance standards...

21 CFR 864.7340 - Fibrinogen determination system.

Code of Federal Regulations, 2011 CFR

2011-04-01

... disseminated intravascular coagulation (nonlocalized clotting within the blood vessels) and primary fibrinolysis (the dissolution of fibrin in a blood clot). (b) Classification. Class II (performance standards...

21 CFR 864.7340 - Fibrinogen determination system.

Code of Federal Regulations, 2014 CFR

2014-04-01

... disseminated intravascular coagulation (nonlocalized clotting within the blood vessels) and primary fibrinolysis (the dissolution of fibrin in a blood clot). (b) Classification. Class II (performance standards...

21 CFR 864.7340 - Fibrinogen determination system.

Code of Federal Regulations, 2013 CFR

2013-04-01

... disseminated intravascular coagulation (nonlocalized clotting within the blood vessels) and primary fibrinolysis (the dissolution of fibrin in a blood clot). (b) Classification. Class II (performance standards...

Safety and efficacy of stenting nonthrombotic iliac vein lesions in octogenarians and nonagenarians in an office setting.

PubMed

Kibrik, Pavel; Eisenberg, Justin; Alsheekh, Ahmad; Rizvi, Syed Ali; Aurshina, Afsha; Marks, Natalie; Hingorani, Anil; Ascher, Enrico

2018-02-01

Objectives Treatment options for venous insufficiency are rapidly evolving in the office setting and include venography, intravascular ultrasound, and venous stenting. Non-thrombotic iliac vein lesions assessment and treatment in an office setting is currently an area of interest. The purpose of this study is to demonstrate the safety and efficacy of evaluating non-thrombotic iliac vein lesion with this office-based procedure in octogenarians and nonagenarians. Methods From January 2012 through December 2013, 300 non-thrombotic iliac vein lesion limbs in 192 patients with venous insufficiency ≥80 years old were evaluated for non-thrombotic iliac vein lesion. Patients were evaluated and treated with venography, intravascular ultrasound, and stent placement for significant lesions demonstrated by greater than 50% diameter or cross-sectional area reduction. Group 1: 168 of these patients were octogenarians; female/male ratio was 1.75:1, bilateral in 89/168 patients (53%), left sided in 131/259 limbs (51%), right sided in 128 limbs (49%), average age 83.5 ± 2.6 years (range 80-89) compared to Group 2: 24 nonagenarians; female/male was 3:1, bilateral in 17/24 patients (70%), left sided in 20/41 limbs (49%), right sided in 21/41 limbs (51%), average age 92.9 ± 2.2 years (range 90-99). Stent related outcomes were evaluated with communication to the patient within 24 h to assess post-procedure pain followed by serial iliocaval ultrasonography. Results Out of the 300 limbs evaluated, in Group 1, 86% of limbs had stents placed compared to 90% in Group 2 and 11% of both groups had two stents placed. Overall improvement in pain, edema, and ulcers was reported in 147 (59%) of octogenarians and 24 (65%) of nonagenarians. There were no surgical site infections, pseudo-aneurysms, arteriovenous fistulas, or femoral artery injuries. No patients required transfusion within three days post-operatively and there were no 30-day mortalities in both sets of patients. Conclusions Our results demonstrate that there is no statistical difference in the outcome of performing venography, intravascular ultrasound, and stent placement in an office-based setting in octogenarians and nonagenarians. Both groups maintained a similar safety profile with low morbidity and mortality. In conclusion, we believe that the treatment of non-thrombotic iliac vein lesion in an office-based setting is safe and efficacious in both groups.

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

Weishaupt, Dominik; Hilfiker, Paul R.; Schmidt, Michaela

Purpose: To describe the three-dimensional magnetic resonance angiography (3D MRA) imaging appearance of the pulmonary arteries following administration of a superparamagnetic iron oxide blood pool agent to human volunteers, and to demonstrate in an animal model (pigs) how this technique can be used to detect pulmonary parenchymal hemorrhage. Methods: Two volunteers were examined following the intravenous administration of a superparamagnetic iron oxide blood pool agent (NC100150 Injection, Nycomed Amersham Imaging, Wayne, PA, USA). T1-weighted 3D gradient recalled echo (GRE) image sets (TR/TE 5.1/1.4 msec, flip angle 30 deg.) were acquired breathheld over 24 sec. To assess the detectability of pulmonarymore » bleeding with intravascular MR contrast, pulmonary parenchymal injuries were created in two animals under general anesthesia, and fast T1-weighted 3D GRE image sets collected before and after the injury. Results: Administration of the intravascular contrast in the two volunteers resulted in selective enhancement of the pulmonary vasculature permitting complete visualization and excellent delineation of central, segmental, and subsegmental arteries. Following iatrogenic injury in the two animals, pulmonary hemorrhage was readily detected on the 3D image sets. Conclusion: The data presented illustrate that ultrafast 3D GRE MR imaging in conjunction with an intravenously administered intravascular blood pool agent can be used to perform high-quality pulmonary MRA as well as to detect pulmonary hemorrhage.« less

Subsequent development of fibroatheromas with inflamed fibrous caps can be predicted by intracoronary near infrared spectroscopy.

PubMed

Patel, Dhavalkumar; Hamamdzic, Damir; Llano, Raul; Patel, Daivesh; Cheng, Lan; Fenning, Robert S; Bannan, Khalid; Wilensky, Robert L

2013-02-01

To prospectively evaluate whether the development of fibroatheromas exhibiting features of potential instability can be detected and predicted by serial invasive imaging. Multivessel intravascular ultrasound and near infrared spectroscopy (NIRS) were performed in diabetic/hypercholesterolemic pigs 3, 6, and 9 months after induction. Animals were euthanized at 9 months and histological/immunohistochemical evaluation of the arteries was performed (n=304 arterial segments). Intravascular ultrasound demonstrated, over time, a progressive increase in plaque + media and necrotic core areas and positive vascular remodeling. By histology, NIRS+ lesions were significantly more likely to be a high-risk fibroatheroma (P=0.0001) containing larger plaque (P<0.0001) and necrotic core areas (P<0.0019) and thinner fibrous caps (P=0.04). NIRS + fibroatheromas possessed a greater concentration of inflammatory cells demonstrating protease activity (P=0.006), and proliferating (P=0.016), and apoptotic cells (P=0.04) within the fibrous cap. Eighty-eight percent of NIRS+ lesions at 3 and 6 months subsequently developed into a fibroatheroma at 9 months (P<0.01). By multivariate analysis NIRS positivity at 6 months predicted the subsequent presence of a fibroatheroma at 9 months (P=0.005; odds ratio, 2.71). The future development of inflamed fibroatheromas with thinner fibrous caps, greater plaque, and necrotic core areas, and posessing characteristics of increased plaque instability were detected by intravascular ultrasound/NIRS imaging.

Development of a 0.014-in., anti-solenoid loop MR imaging guidewire for intravascular 3.0-T MR imaging.

PubMed

Gu, Huidong; Zhang, Feng; Meng, Yanfeng; Qiu, Bensheng; Yang, Xiaoming

2011-09-01

This study aimed to develop a 0.014-in., anti-solenoid loop (ASL) magnetic resonance imaging guidewire (MRIG) for intravascular 3.0-T MR imaging. We first designed the ASL MRIG, which was made of a coaxial cable with its extended inner conductor and outer conductor connected to two micro-anti-solenoids. We then evaluated in vitro the functionality of the ASL MRIG by imaging a "vessel" in a phantom and achieving signal-to-noise ratio (SNR) and SNR contour map of the new 0.014-in. ASL MRIG. Subsequently, we validated in vivo the feasibility of using the ASL MRIG to generate intravenous 3.0-T MR images of parallel iliofemoral arteries of near-human-sized living pigs. In vitro evaluation showed that the 0.014-in. ASL MRIG functioned well as a receiver coil with the 3.0-T MR scanner, clearly displaying the vessel wall with even distribution of MR signals and SNR contours from the ASL MRIG. Of the in vivo studies, the new ASL MRIG enabled us to successfully generate intravenous 3.0-T MR imaging of the iliofemoral arteries. This study confirms that it is possible to build such small-looped MRIG at 0.014 in. for intravascular 3.0-T MR imaging. Copyright © 2011 Elsevier Inc. All rights reserved.

Propagation of thrombosis by neutrophils and extracellular nucleosome networks

PubMed Central

Pfeiler, Susanne; Stark, Konstantin; Massberg, Steffen; Engelmann, Bernd

2017-01-01

Neutrophils, early mediators of the innate immune defense, are recruited to developing thrombi in different types of thrombosis. They amplify intravascular coagulation by stimulating the tissue factor-dependent extrinsic pathway via inactivation of endogenous anticoagulants, enhancing factor XII activation or decreasing plasmin generation. Neutrophil-dependent prothrombotic mechanisms are supported by the externalization of decondensed nucleosomes and granule proteins that together form neutrophil extracellular traps. These traps, either in intact or fragmented form, are causally involved in various forms of experimental thrombosis as first indicated by their role in the enhancement of both microvascular thrombosis during bacterial infection and carotid artery thrombosis. Neutrophil extracellular traps can be induced by interactions of neutrophils with activated platelets; vice versa, these traps enhance adhesion of platelets via von Willebrand factor. Neutrophil-induced microvascular thrombus formation can restrict the dissemination and survival of blood-borne bacteria and thereby sustain intravascular immunity. Dysregulation of this innate immune pathway may support sepsis-associated coagulopathies. Notably, neutrophils and extracellular nucleosomes, together with platelets, critically promote fibrin formation during flow restriction-induced deep vein thrombosis. Neutrophil extracellular traps/extracellular nucleosomes are increased in thrombi and in the blood of patients with different vaso-occlusive pathologies and could be therapeutically targeted for the prevention of thrombosis. Thus, during infections and in response to blood vessel damage, neutrophils and externalized nucleosomes are major promoters of intravascular blood coagulation and thrombosis. PMID:27927771

Enriched Air Nitrox Breathing Reduces Venous Gas Bubbles after Simulated SCUBA Diving: A Double-Blind Cross-Over Randomized Trial.

PubMed

Souday, Vincent; Koning, Nick J; Perez, Bruno; Grelon, Fabien; Mercat, Alain; Boer, Christa; Seegers, Valérie; Radermacher, Peter; Asfar, Pierre

2016-01-01

To test the hypothesis whether enriched air nitrox (EAN) breathing during simulated diving reduces decompression stress when compared to compressed air breathing as assessed by intravascular bubble formation after decompression. Human volunteers underwent a first simulated dive breathing compressed air to include subjects prone to post-decompression venous gas bubbling. Twelve subjects prone to bubbling underwent a double-blind, randomized, cross-over trial including one simulated dive breathing compressed air, and one dive breathing EAN (36% O2) in a hyperbaric chamber, with identical diving profiles (28 msw for 55 minutes). Intravascular bubble formation was assessed after decompression using pulmonary artery pulsed Doppler. Twelve subjects showing high bubble production were included for the cross-over trial, and all completed the experimental protocol. In the randomized protocol, EAN significantly reduced the bubble score at all time points (cumulative bubble scores: 1 [0-3.5] vs. 8 [4.5-10]; P < 0.001). Three decompression incidents, all presenting as cutaneous itching, occurred in the air versus zero in the EAN group (P = 0.217). Weak correlations were observed between bubble scores and age or body mass index, respectively. EAN breathing markedly reduces venous gas bubble emboli after decompression in volunteers selected for susceptibility for intravascular bubble formation. When using similar diving profiles and avoiding oxygen toxicity limits, EAN increases safety of diving as compared to compressed air breathing. ISRCTN 31681480.

Development of an intravascular heating source using an MR imaging guidewire.

PubMed

Qiu, Bensheng; Yeung, Christopher J; Du, Xiangying; Atalar, Ergin; Yang, Xiaoming

2002-12-01

To develop a novel endovascular heating source using a magnetic resonance (MR) imaging guidewire (MRIG) to deliver controlled microwave energy into the target vessel for thermal enhancement of vascular gene transfection. A 0.032-inch MRIG was connected to a 2.45-GHz microwave generator. We 1) calculated the microwave power loss along the MRIG, 2) simulated the power distribution around the MRIG, 3) measured the temperature increase vs. input power with the MRIG, and 4) evaluated the thermal effect on the balloon-compressed/microwave-heated aorta of six living rabbits. In addition, during balloon inflation, we also simultaneously generated high-resolution MR images of the aortic wall. The power loss was calculated to be 3.9 dB along the MRIG. The simulation-predicted power distribution pattern was cylindrically symmetric, analogous to the geometry of vessels. Under balloon compression, the vessel wall could be locally heated at 41 degrees C with no thermal damage apparent on histology. This study demonstrates the possibility of using the MRIG as a multifunctional device, not only as a receiver antenna to generate intravascular high-resolution MR images of atherosclerotic plaques and as a conventional guidewire to guide endovascular interventions during MR imaging, but also as a potential intravascular heating source to produce local heat for thermal enhancement of vascular gene transfection. Copyright 2002 Wiley-Liss, Inc.

Intravascular photoacoustic imaging: a new tool for vulnerable plaque identification.

PubMed

Jansen, Krista; van Soest, Gijs; van der Steen, Antonius F W

2014-06-01

The vulnerable atherosclerotic plaque is believed to be at the root of the majority of acute coronary events. Even though the exact origins of plaque vulnerability remain elusive, the thin-cap fibroatheroma, characterized by a lipid-rich necrotic core covered by a thin fibrous cap, is considered to be the most prominent type of vulnerable plaque. No clinically available imaging technique can characterize atherosclerotic lesions to the extent needed to determine plaque vulnerability prognostically. Intravascular photoacoustic imaging (IVPA) has the potential to take a significant step in that direction by imaging both plaque structure and composition. IVPA is a natural extension of intravascular ultrasound that adds tissue type specificity to the images. IVPA utilizes the optical contrast provided by the differences in the absorption spectra of plaque components to image composition. Its capability to image lipids in human coronary atherosclerosis has been shown extensively ex vivo and has recently been translated to an in vivo animal model. Other disease markers that have been successfully targeted are calcium and inflammatory markers, such as macrophages and matrix metalloproteinase; the latter two through application of exogenous contrast agents. By simultaneously displaying plaque morphology and composition, IVPA can provide a powerful prognostic marker for disease progression, and as such has the potential to transform the current practice in percutaneous coronary intervention. Copyright © 2014 World Federation for Ultrasound in Medicine & Biology. Published by Elsevier Inc. All rights reserved.

Contribution of intravascular versus interstitial purines and nitric oxide in the regulation of exercise hyperaemia in humans

PubMed Central

Hellsten, Y; Nyberg, M; Mortensen, S P

2012-01-01

The regulation of blood flow to skeletal muscle involves a complex interaction between several locally formed vasodilators that are produced both in the skeletal muscle interstitium and intravascularly. The gas nitric oxide (NO) and the purines ATP and adenosine, are potent vasodilators that are formed by multiple cell types and released into the skeletal muscle interstitium and in plasma in response to muscle contraction. Cellular sources of ATP and NO in plasma are erythrocytes and endothelial cells, whereas interstitial sources are skeletal muscle cells and endothelial cells. Adenosine originates primarily from extracellular degradation of ATP. During exercise the concentrations of ATP and adenosine increase markedly in the interstitium with smaller increases occurring in plasma, and thus the interstitial concentration during exercise is severalfold higher than in plasma. The concentration of NO metabolites (NOx) in interstitium and plasma does not change during exercise and is similar in the two compartments. Adenosine and NO have been shown to contribute to exercise hyperaemia whereas the role of ATP remains unclear due to lack of specific purinergic receptor blockers. The relative role of intravascular versus interstitial vasodilators is not known but evidence suggests that both compartments are important. In cardiovascular disease, a reduced capacity to form adenosine in the muscle interstitium may be a contributing factor in increased peripheral vascular resistance. PMID:22733661

Adaptive windowing in contrast-enhanced intravascular ultrasound imaging.

PubMed

Lindsey, Brooks D; Martin, K Heath; Jiang, Xiaoning; Dayton, Paul A

2016-08-01

Intravascular ultrasound (IVUS) is one of the most commonly-used interventional imaging techniques and has seen recent innovations which attempt to characterize the risk posed by atherosclerotic plaques. One such development is the use of microbubble contrast agents to image vasa vasorum, fine vessels which supply oxygen and nutrients to the walls of coronary arteries and typically have diameters less than 200μm. The degree of vasa vasorum neovascularization within plaques is positively correlated with plaque vulnerability. Having recently presented a prototype dual-frequency transducer for contrast agent-specific intravascular imaging, here we describe signal processing approaches based on minimum variance (MV) beamforming and the phase coherence factor (PCF) for improving the spatial resolution and contrast-to-tissue ratio (CTR) in IVUS imaging. These approaches are examined through simulations, phantom studies, ex vivo studies in porcine arteries, and in vivo studies in chicken embryos. In phantom studies, PCF processing improved CTR by a mean of 4.2dB, while combined MV and PCF processing improved spatial resolution by 41.7%. Improvements of 2.2dB in CTR and 37.2% in resolution were observed in vivo. Applying these processing strategies can enhance image quality in conventional B-mode IVUS or in contrast-enhanced IVUS, where signal-to-noise ratio is relatively low and resolution is at a premium. Copyright © 2016 Elsevier B.V. All rights reserved.

High speed intravascular photoacoustic imaging of atherosclerotic arteries (Conference Presentation)

NASA Astrophysics Data System (ADS)

Piao, Zhonglie; Ma, Teng; Qu, Yueqiao; Li, Jiawen; Yu, Mingyue; He, Youmin; Shung, K. Kirk; Zhou, Qifa; Kim, Chang-Seok; Chen, Zhongping

2016-02-01

Cardiovascular disease is the leading cause of death in the industrialized nations. Accurate quantification of both the morphology and composition of lipid-rich vulnerable atherosclerotic plaque are essential for early detection and optimal treatment in clinics. In previous works, intravascular photoacoustic (IVPA) imaging for detection of lipid-rich plaque within coronary artery walls has been demonstrated in ex vivo, but the imaging speed is still limited. In order to increase the imaging speed, a high repetition rate laser is needed. In this work, we present a high speed integrated IVPA/US imaging system with a 500 Hz optical parametric oscillator laser at 1725 nm. A miniature catheter with 1.0 mm outer diameter was designed with a 200 μm multimode fiber and an ultrasound transducer with 45 MHz center frequency. The fiber was polished at 38 degree and enclosed in a glass capillary for total internal reflection. An optical/electrical rotary junction and pull-back mechanism was applied for rotating and linearly scanning the catheter to obtain three-dimensional imaging. Atherosclerotic rabbit abdominal aorta was imaged as two frame/second at 1725 nm. Furthermore, by wide tuning range of the laser wavelength from 1680 nm to 1770 nm, spectroscopic photoacoustic analysis of lipid-mimicking phantom and an human atherosclerotic artery was performed ex vivo. The results demonstrated that the developed IVPA/US imaging system is capable for high speed intravascular imaging for plaque detection.

Canine blood volume and cardiovascular function during hyperthermia.

PubMed

Miki, K; Morimoto, T; Nose, H; Itoh, T; Yamada, S

1983-08-01

The effect of acute hyperthermia on hemodynamic functions and blood volume regulation was examined on eight splenectomized dogs. Elevation of core body temperature by 2 degrees C over 90 min caused significant increase in cardiac output (11.2 +/- 12.5 ml X min-1 X kg-1 or about 10%) and significant decrease in total peripheral resistance (TPR; -1.3 +/- 1.0 mmHg X s X ml-1 or about 20%), whereas blood volume (BV), plasma oncotic pressure, and intravascular protein mass remained unchanged. Thus the raised core temperature caused peripheral vasodilation with decreased TPR and compensatory increase in cardiac output. Because BV remained unchanged during warming, mobilization of extravascular fluid did not occur; only the redistribution of blood to the vasodilated cutaneous circulation took place. To assess the effects of heat stress on transvascular fluid equilibrium, Ringer solution (10.7 ml X kg-1 X 10 min-1) was infused under normothermic and hyperthermic conditions. The volume of fluid retained within the intravascular space under equilibrium state was 33.5% in hyperthermia and 9.4% in normothermia. In hyperthermia, the transvascular fluid shift and urinary output were decreased both during and after infusion. The role of preferential fluid retention within the intravascular space observed during hyperthermia was discussed in relation to the mechanism to maintain cardiovascular function and BV under heat stress.

Intravascular ultrasound

MedlinePlus

... heart attack. IVUS has helped providers understand how stents become clogged. This is called stent restenosis. ... IVUS is commonly done to make sure a stent is correctly placed during angioplasty. It may also ...

Extravasation Injuries in Adults

PubMed Central

Al-Benna, S.; O'Boyle, C.; Holley, J.

2013-01-01

Insertion of an intravascular catheter is one of the most common invasive procedures in hospitals worldwide. These intravascular lines are crucial in resuscitation, allow vital medication to be administered, and can be used to monitor the patients' real-time vital parameters. There is, however, growing recognition of potential risks to life and limb associated with their use. Medical literature is now replete with isolated case reports of complications succinctly described by Garden and Laussen (2004) as “An unending supply of “unusual” complications from central venous catheters.” This paper reviews complications of venous and arterial catheters and discusses treatment approaches and methods to prevent complications, based on current evidence and endeavours to provide information and guidance that will enable practitioners to prevent, recognise, and successfully treat extravasation injuries in adults. PMID:23738141

Acute Kidney Injury due to Menstruation-related Disseminated Intravascular Coagulation in an Adenomyosis Patient: A Case Report

PubMed Central

Son, Jungmin; Seong, Eun Young; Song, Sang Heon; Lee, Soo Bong; Kang, Jin; Yang, Byeong Yun; Lee, Su Jin; Choi, Jong-Ryeol; Lee, Kyu-Sup; Kwak, Ihm Soo

2010-01-01

The authors report a case of acute kidney injury (AKI) resulting from menstruation-related disseminated intravascular coagulation (DIC) in an adenomyosis patient. A 40-yr-old woman who had received gonadotropin for ovulation induction therapy presented with anuria and an elevated serum creatinine level. Her medical history showed primary infertility with diffuse adenomyosis. On admission, her pregnancy test was negative and her menstrual cycle had started 1 day previously. Laboratory data were consistent with DIC, and it was believed to be related to myometrial injury resulting from heavy intramyometrial menstrual flow. Gonadotropin is considered to play an important role in the development of fulminant DIC. This rare case suggests that physicians should be aware that gonadotropin may provoke fulminant DIC in women with adenomyosis. PMID:20808684

High-speed Intravascular Photoacoustic Imaging of Lipid-laden Atherosclerotic Plaque Enabled by a 2-kHz Barium Nitrite Raman Laser

PubMed Central

Wang, Pu; Ma, Teng; Slipchenko, Mikhail N.; Liang, Shanshan; Hui, Jie; Shung, K. Kirk; Roy, Sukesh; Sturek, Michael; Zhou, Qifa; Chen, Zhongping; Cheng, Ji-Xin

2014-01-01

Lipid deposition inside the arterial wall is a key indicator of plaque vulnerability. An intravascular photoacoustic (IVPA) catheter is considered a promising device for quantifying the amount of lipid inside the arterial wall. Thus far, IVPA systems suffered from slow imaging speed (~50 s per frame) due to the lack of a suitable laser source for high-speed excitation of molecular overtone vibrations. Here, we report an improvement in IVPA imaging speed by two orders of magnitude, to 1.0 s per frame, enabled by a custom-built, 2-kHz master oscillator power amplifier (MOPA)-pumped, barium nitrite [Ba(NO3)2] Raman laser. This advancement narrows the gap in translating the IVPA technology to the clinical setting. PMID:25366991

Massive haematuria successfully managed by intravesical ankaferd in a haemodialysis patient complicated with disseminated intravascular coagulation

PubMed Central

Solak, Yalcin; Gaipov, Abduzhappar; Ozbek, Orhan; Hassan, Mustafa Aziz; Yeksan, Mehdi

2012-01-01

Massive haematuria is a life-threatening condition, demanding immediate management of bleeding. The mortality is very high in the case of delayed management of bleeding, especially in elderly patients with concomitant comorbidity. The treatment options of haematuria are wide, and depend on underlying conditions. However, therapeutic choices are limited in the presence of massive and intractable haematuria caused by disseminated intravascular coagulation (DIC). Ankaferd blood stopper (ABS) is a novel, commercially available, haemostatic agent, which has been approved by the Ministry of Health for local use in Turkey. Here, for the first time in the literature, we report a case of diffuse intravesical bleeding stopped by intravesical use of ABS in a 72-year-old man, haemodialysis patient complicated with sepsis and DIC. PMID:23266773

Intravascular Papillary Endothelial Hyperplasia (Masson’s Tumor) of the Radial Artery: A Case Report

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

Stark, Christopher, E-mail: Christopher.stark@uvmhealth.org; Olsen, Daniel; Morris, Christopher

Intravascular papillary endothelial hyperplasia (IPEH), often referred to as Masson’s tumor, is a benign non-neoplastic vascular lesion of the skin and subcutaneous tissues. Although it is rare, knowledge of the existence of IPEH is important as it can mimic other benign and malignant tumors, most notably angiosarcoma. IPEH remains an incompletely understood entity; however, most consider it to be the result of reactive endothelial proliferation following thrombus formation within a vessel, vascular malformation, or adjacent to a vessel. In this article, we report a case of IPEH arising within an arteriovenous malformation of the radial artery and present accompanying multimodalitymore » imaging and pathology figures. We will also describe the clinical presentation, pathophysiology, histology, imaging features, and management of IPEH.« less

Intravascular forward-looking ultrasound transducers for microbubble-mediated sonothrombolysis.

PubMed

Kim, Jinwook; Lindsey, Brooks D; Chang, Wei-Yi; Dai, Xuming; Stavas, Joseph M; Dayton, Paul A; Jiang, Xiaoning

2017-06-14

Effective removal or dissolution of large blood clots remains a challenge in clinical treatment of acute thrombo-occlusive diseases. Here we report the development of an intravascular microbubble-mediated sonothrombolysis device for improving thrombolytic rate and thus minimizing the required dose of thrombolytic drugs. We hypothesize that a sub-megahertz, forward-looking ultrasound transducer with an integrated microbubble injection tube is more advantageous for efficient thrombolysis by enhancing cavitation-induced microstreaming than the conventional high-frequency, side-looking, catheter-mounted transducers. We developed custom miniaturized transducers and demonstrated that these transducers are able to generate sufficient pressure to induce cavitation of lipid-shelled microbubble contrast agents. Our technology demonstrates a thrombolysis rate of 0.7 ± 0.15 percent mass loss/min in vitro without any use of thrombolytic drugs.

Back-to-back optical coherence tomography-ultrasound probe for co-registered three-dimensional intravascular imaging with real-time display

NASA Astrophysics Data System (ADS)

Li, Jiawen; Ma, Teng; Jing, Joseph; Zhang, Jun; Patel, Pranav M.; Shung, K. Kirk; Zhou, Qifa; Chen, Zhongping

2014-03-01

We have developed a novel integrated optical coherence tomography (OCT)-intravascular ultrasound (IVUS) probe, with a 1.5 mm-long rigid-part and 0.9 mm outer diameter, for real-time intracoronary imaging of atherosclerotic plaques and guiding interventional procedures. By placing the OCT ball lens and IVUS 45MHz single element transducer back-to-back at the same axial position, this probe can provide automatically co-registered, co-axial OCT-IVUS imaging. To demonstrate its capability, 3D OCT-IVUS imaging of a pig's coronary artery in real-time displayed in polar coordinates, as well as images of two major types of advanced plaques in human cadaver coronary segments, was obtained using this probe and our upgraded system. Histology validation is also presented.

21 CFR 870.1200 - Diagnostic intravascular catheter.

Code of Federal Regulations, 2010 CFR

2010-04-01

... intracardiac pressures, to sample blood, and to introduce substances into the heart and vessels. Included in this generic device are right-heart catheters, left-heart catheters, and angiographic catheters, among...

21 CFR 864.7300 - Fibrin monomer paracoagulation test.

Code of Federal Regulations, 2011 CFR

2011-04-01

... clotting within a blood vessel) or in the differential diagnosis between disseminated intravascular coagulation and primary fibrinolysis (dissolution of the fibrin in a blood clot). (b) Classification. Class II...

21 CFR 864.7300 - Fibrin monomer paracoagulation test.

Code of Federal Regulations, 2012 CFR

2012-04-01

... clotting within a blood vessel) or in the differential diagnosis between disseminated intravascular coagulation and primary fibrinolysis (dissolution of the fibrin in a blood clot). (b) Classification. Class II...

21 CFR 864.7320 - Fibrinogen/fibrin degradation products assay.

Code of Federal Regulations, 2014 CFR

2014-04-01

... dissolution of the fibrin in a blood clot) and in monitoring therapy for disseminated intravascular coagulation (nonlocalized clotting in the blood vessels). (b) Classification. Class II (performance standards...

21 CFR 864.7300 - Fibrin monomer paracoagulation test.

Code of Federal Regulations, 2010 CFR

2010-04-01

... clotting within a blood vessel) or in the differential diagnosis between disseminated intravascular coagulation and primary fibrinolysis (dissolution of the fibrin in a blood clot). (b) Classification. Class II...

21 CFR 864.7320 - Fibrinogen/fibrin degradation products assay.

Code of Federal Regulations, 2013 CFR

2013-04-01

... dissolution of the fibrin in a blood clot) and in monitoring therapy for disseminated intravascular coagulation (nonlocalized clotting in the blood vessels). (b) Classification. Class II (performance standards...

21 CFR 864.7320 - Fibrinogen/fibrin degradation products assay.

Code of Federal Regulations, 2012 CFR

2012-04-01

... dissolution of the fibrin in a blood clot) and in monitoring therapy for disseminated intravascular coagulation (nonlocalized clotting in the blood vessels). (b) Classification. Class II (performance standards...

21 CFR 864.7300 - Fibrin monomer paracoagulation test.

Code of Federal Regulations, 2014 CFR

2014-04-01

... clotting within a blood vessel) or in the differential diagnosis between disseminated intravascular coagulation and primary fibrinolysis (dissolution of the fibrin in a blood clot). (b) Classification. Class II...

21 CFR 864.7320 - Fibrinogen/fibrin degradation products assay.

Code of Federal Regulations, 2011 CFR

2011-04-01

... dissolution of the fibrin in a blood clot) and in monitoring therapy for disseminated intravascular coagulation (nonlocalized clotting in the blood vessels). (b) Classification. Class II (performance standards...

21 CFR 864.7300 - Fibrin monomer paracoagulation test.

Code of Federal Regulations, 2013 CFR

2013-04-01

... clotting within a blood vessel) or in the differential diagnosis between disseminated intravascular coagulation and primary fibrinolysis (dissolution of the fibrin in a blood clot). (b) Classification. Class II...

Hemolysis

MedlinePlus

... eds. Goldman's Cecil Medicine . 25th ed. Philadelphia, PA: Elsevier Saunders; 2016:chap 161. Gallagher PG. Red blood ... Basic Principles and Practice . 6th ed. Philadelphia, PA: Elsevier; 2013:chap 43. Michel M. Autoimmune and intravascular ...

21 CFR 870.1200 - Diagnostic intravascular catheter.

Code of Federal Regulations, 2012 CFR

2012-04-01

... intracardiac pressures, to sample blood, and to introduce substances into the heart and vessels. Included in this generic device are right-heart catheters, left-heart catheters, and angiographic catheters, among...

21 CFR 870.1200 - Diagnostic intravascular catheter.

Code of Federal Regulations, 2011 CFR

2011-04-01

... intracardiac pressures, to sample blood, and to introduce substances into the heart and vessels. Included in this generic device are right-heart catheters, left-heart catheters, and angiographic catheters, among...

21 CFR 870.1200 - Diagnostic intravascular catheter.

Code of Federal Regulations, 2013 CFR

2013-04-01

... intracardiac pressures, to sample blood, and to introduce substances into the heart and vessels. Included in this generic device are right-heart catheters, left-heart catheters, and angiographic catheters, among...

21 CFR 870.1200 - Diagnostic intravascular catheter.

Code of Federal Regulations, 2014 CFR

2014-04-01

... intracardiac pressures, to sample blood, and to introduce substances into the heart and vessels. Included in this generic device are right-heart catheters, left-heart catheters, and angiographic catheters, among...

Vascular Shunts in Civilian Trauma

PubMed Central

Abou Ali, Adham N.; Salem, Karim M.; Alarcon, Louis H.; Bauza, Graciela; Pikoulis, Emmanuel; Chaer, Rabih A.; Avgerinos, Efthymios D.

2017-01-01

Experience with temporary intravascular shunts (TIVS) for vessel injury comes from the military sector and while the indications might be clear in geographically isolated and under resourced war zones, this may be an uncommon scenario in civilian trauma. Data supporting TIVS use in civilian trauma have been extrapolated from the military literature where it demonstrated improved life and limb salvage. Few non-comparative studies from the civilian literature have also revealed similar favorable outcomes. Still, TIVS placement in civilian vascular injuries is uncommon and by some debatable given the absence of clear indications for placement, the potential for TIVS-related complications, the widespread resources for immediate and definitive vascular repair, and the need for curtailing costs and optimizing resources. This article reviews the current evidence and the role of TIVS in contemporary civilian trauma management. PMID:28775985

Compatible Transfusion Therapy for Paroxysmal Cold Hemoglobinuria

ERIC Educational Resources Information Center

Rausen, Aaron R.; And Others

1975-01-01

Presented are case histories of two children, ages 2 and 4 years, with paroxysmal cold hemoglobinuria (PCH, a syndrome characterized by acute intravascular hemoglobin dissolution and hemoglobin in the urine). (Author/CL)

Pharmacological characterization of a novel phosphodiesterase type 5 (PDE5) inhibitor lodenafil carbonate on human and rabbit corpus cavernosum.

PubMed

Toque, Haroldo A; Teixeira, Cleber E; Lorenzetti, Raquel; Okuyama, Cristina E; Antunes, Edson; De Nucci, Gilberto

2008-09-04

Nitrergic nerves and endothelial cells release nitric oxide (NO) in the corpus cavernosum, a key mediator that stimulates soluble guanylyl cyclase to increase cGMP levels causing penile erection. Phosphodiesterase 5 (PDE5) inhibitors, such as sildenafil, prolong the NO effects by inhibiting cGMP breakdown. Here, we report a novel PDE5 inhibitor, lodenafil carbonate, (Bis-(2-{4-[4-ethoxy-3-(1-methyl-7-oxo-3-propyl-6,7-dihydro-1H-pyrazolo[4,3-d]pyrimidin-5-yl)-benzenesulfonyl]piperazin-1-yl}-ethyl)carbonate) that is a dimer of lodenafil. We therefore aimed to compare the effects of sildenafil, lodenafil and lodenafil carbonate on in vitro human and rabbit cavernosal relaxations, activity of crude PDE extracts from human platelets, as well as stability and metabolic studies in rat, dog and human plasma. Pharmacokinetic evaluations after intravenous and oral administration were performed in male beagles. Functional experiments were conducted using organ bath techniques. Pharmacokinetics was studied in beagles by liquid chromatography coupled to tandem mass spectrometry (LC-MS/MS), following oral or intravascular administration. All PDE5 inhibitors tested concentration-dependently relaxed (0.001-100 microM) phenylephrine-precontracted rabbit and human corpus cavernosum. The cavernosal relaxations evoked by either acetylcholine (0.01-100 microM) or electrical field stimulation (EFS, 1-20 Hz) were markedly potentiated by sildenafil, lodenafil and lodenafil carbonate. Lodenafil carbonate was more potent to inhibit the cGMP hydrolysis in PDE extracts compared with lodenafil and sildenafil. Following intravascular and single oral administration of lodenafil carbonate, only lodenafil and norlodenafil were detected in vivo. These results indicate that lodenafil carbonate works as a prodrug, being lodenafil the active moiety of lodenafil carbonate.

Colloid osmotic pressure and extravasation of plasma proteins following infusion of Ringer's acetate and hydroxyethyl starch 130/0.4.

PubMed

Zdolsek, J H; Bergek, C; Lindahl, T L; Hahn, R G

2015-11-01

During fluid infusion therapy, plasma proteins are diluted and leak from the intravascular space, which alters the colloid osmotic pressure (COP) and potentially affects coagulation. We hypothesised that acetated Ringer's and starch solution, alone or in combination, influence these mechanisms differently. On different occasions, 10 male volunteers were infused with 20 ml/kg acetated Ringer's and 10 ml/kg 6% hyroxyethyl starch 130/0.4 (Voluven(®) ) alone or in combination (first with starch solution followed by Ringer's solution). Blood samples were collected every 30-min for measurements of COP, blood haemoglobin, platelets, and plasma concentrations of albumin, immunoglobulins (IgG and IgM), coagulation factor VII (FVII), fibrinogen, cystatin C, activated partial thromboplastin time (APTT) and prothrombin international normalised ratio (PT-INR). Changes were compared with the haemoglobin-derived plasma dilution. The COP increased by 8.4% (SD 3) with starch and decreased by 26.2% (7.9) with Ringer's. These infusions diluted the plasma by 23.4% (5.3) and 18.7% (4.9) respectively. The COP changes in the combined experiment followed the same pattern as the individual infusions. Albumin and IgG changes in excess of the plasma dilution were very subtle. The intravascular contents of the IgM and platelets decreased, whereas FVII, fibrinogen and cystatin C increased. PT-INR increased by 1/3 of the plasma dilution, whereas changes in APTT did not correlate with the plasma dilution. The starch increased COP and only minor capillary leak occurred in healthy volunteers. The fluid-induced plasma dilution correlated with mild impairment of the extrinsic coagulation pathway but not of the intrinsic pathway. © 2015 The Acta Anaesthesiologica Scandinavica Foundation. Published by John Wiley & Sons Ltd.

Comparison of vascular distensibility in the upper and lower extremity.

PubMed

Eiken, O; Kölegård, R

2004-07-01

Because of the great differences in hydrostatic pressure acting along the blood vessels in the erect posture, leg vessels are exposed to greater transmural pressures than arm vessels. The in vivo pressure-distension relationship of arteries, arterioles and veins in the arm were compared with those of the leg. Experiments were performed with the subject (n = 11) positioned in a pressure chamber with an arm or lower leg (test limb) extended at heart level through a hole in the chamber door. Intravascular pressure in the arm/lower leg was increased by stepwise increasing chamber pressure to +180 and +210 mmHg, respectively. Diameters of blood vessels and arterial flow were measured using ultrasonographic/Doppler techniques. Changes in forearm and lower leg volumes were assessed using an impedance technique. The subject rated perceived pain in the test limb. The brachial and radial arteries were found to be more distensible than the posterior tibial artery (P < 0.001). Likewise, the distension was more pronounced in the cephalic than in the great saphenous vein (P < 0.001). In the brachial artery, but not in the posterior tibial artery, flow increased markedly at the highest levels of distending pressure (P < 0.001). At the highest intravascular pressures, the rate of change in tissue impedance was greater in the forearm than the lower leg (P < 0.01). At any given level of markedly increased pressure, pain was rated higher in the arm than in the leg (P < 0.001). It seems that the wall stiffness of arteries, pre-capillary resistance vessels and veins adapts to meet the long-term demands imposed by the hydrostatic pressure acting locally on the vessel walls.

Oblong-Shaped-Focused Transducers for Intravascular Ultrasound Imaging.

PubMed

Lee, Junsu; Jang, Jihun; Chang, Jin Ho

2017-03-01

In intravascular ultrasound (IVUS) imaging, a transducer is inserted into a blood vessel and rotated to obtain image data. For this purpose, the transducer aperture is typically less than 0.5 mm in diameter, which causes natural focusing to occur in the imaging depth ranging from 1 to 5 mm. Due to the small aperture, however, it is not viable to conduct geometric focusing in order to enhance the spatial resolution of IVUS images. Furthermore, this hampers narrowing the slice thickness of a cross-sectional scan plane in the imaging depth, which leads to lowering spatial and contrast resolutions of IVUS images. To solve this problem, we propose an oblong-shaped-focused transducer for IVUS imaging. Unlike the conventional IVUS transducers with either a circular or a square flat aperture, the proposed transducer has an oblong aperture of which long side is positioned along a blood vessel. This unique configuration makes it possible to conduct geometric focusing at a desired depth in the elevation direction. In this study, furthermore, it is demonstrated that a spherically shaped aperture in both lateral and elevation directions also improves lateral resolution, compared to the conventional flat aperture. To ascertain this, the conventional and the proposed IVUS transducers were designed and fabricated to evaluate and to compare their imaging performances through wire phantom and tissue-mimicking phantom experiments. For the proposed 50-MHz IVUS transducer, a PZT piece of 0.5 × 1.0 mm 2 was spherically shaped for elevation focus at 3 mm by using the conventional press-focusing technique whereas the conventional one has a flat aperture of 0.5 × 0.5 mm 2 . The experimental results demonstrated that the proposed IVUS transducer is capable of improving spatial and contrast resolutions of IVUS images.

Mathematical Modeling of Intravascular Blood Coagulation under Wall Shear Stress

PubMed Central

Rukhlenko, Oleksii S.; Dudchenko, Olga A.; Zlobina, Ksenia E.; Guria, Georgy Th.

2015-01-01

Increased shear stress such as observed at local stenosis may cause drastic changes in the permeability of the vessel wall to procoagulants and thus initiate intravascular blood coagulation. In this paper we suggest a mathematical model to investigate how shear stress-induced permeability influences the thrombogenic potential of atherosclerotic plaques. Numerical analysis of the model reveals the existence of two hydrodynamic thresholds for activation of blood coagulation in the system and unveils typical scenarios of thrombus formation. The dependence of blood coagulation development on the intensity of blood flow, as well as on geometrical parameters of atherosclerotic plaque is described. Relevant parametric diagrams are drawn. The results suggest a previously unrecognized role of relatively small plaques (resulting in less than 50% of the lumen area reduction) in atherothrombosis and have important implications for the existing stenting guidelines. PMID:26222505

(100)-Textured KNN-based thick film with enhanced piezoelectric property for intravascular ultrasound imaging

PubMed Central

Zhu, Benpeng; Zhang, Zhiqiang; Ma, Teng; Yang, Xiaofei; Li, Yongxiang; Shung, K. Kirk; Zhou, Qifa

2015-01-01

Using tape-casting technology, 35 μm free-standing (100)-textured Li doped KNN (KNLN) thick film was prepared by employing NaNbO3 (NN) as template. It exhibited similar piezoelectric behavior to lead containing materials: a longitudinal piezoelectric coefficient (d33) of ∼150 pm/V and an electromechanical coupling coefficient (kt) of 0.44. Based on this thick film, a 52 MHz side-looking miniature transducer with a bandwidth of 61.5% at −6 dB was built for Intravascular ultrasound (IVUS) imaging. In comparison with 40 MHz PMN-PT single crystal transducer, the rabbit aorta image had better resolution and higher noise-to-signal ratio, indicating that lead-free (100)-textured KNLN thick film may be suitable for IVUS (>50 MHz) imaging. PMID:25991874

Intravascular large B-cell lymphoma presenting with anasarca-type edema and acute renal failure.

PubMed

Bilgili, Serap Gunes; Yılmaz, Deniz; Soyoral, Yasemin Usul; Karadag, Ayse Serap; Bayram, Irfan

2013-09-01

Intravascular lymphoma (IVL) is a rare extra nodal subtype (usually of B-cell origin) presenting with infiltration of large neoplastic lymphocytes into lumina of blood vessels, leading to vascular occlusion. The early diagnosis is very crucial, however it is usually diagnosed postmortem investigation in most of the cases. A 56-year-old female presented with elevated creatinine level, and anasarca-type edema that superimposed with hard, indurated, erythematous plaques extending to inguinal region, abdomen, anterior aspect of chest, and face. B-cell IVL was confirmed with skin biopsy. The patient had some degree of clinical improvement following chemotherapy. B-cell IVL presenting with anasarca edema was not previously reported in the literature. Even if its rarity, IVL should be considered in the differential diagnosis of renal failure with anasarca edema.

Gross and microscopic characteristics of stomach cancer with microangiopathic hemolytic anemia and/or disseminated intravascular coagulopathy.

PubMed

Morimatsu, M; Shirouzu, K; Irie, K; Tokunaga, O; Sasaguri, Y

1985-07-01

We described gross and microscopic characteristics of 11 autopsied cases of stomach cancer with microangiopathic hemolytic anemia and/or disseminated intravascular coagulopathy. They were divided into two groups grossly. One was superficial carcinoma and the other diffuse infiltrating and fungating carcinoma. Superficial carcinoma arose multicentrically and showed figures of signet ring cell carcinoma. This condition was accompanied by marked pulmonary tumor emboli and bone marrow dissemination in the initial stage of cancer evolution. Diffuse infiltrating and fungating carcinoma arose in the corpus and showed variable histological features. Dissemination of tumor cells to the bone marrow was seen in the terminal stage. Stomach cancer in this series consisted of two different groups on gross, microscopic and metastatic features. Signet ring cell of superficial carcinoma showed characteristic biological features with respect to local extension and metastasis.

Functional assessment of coronary artery disease by intravascular ultrasound and computational fluid dynamics simulation.

PubMed

Carrizo, Sebastián; Xie, Xinzhou; Peinado-Peinado, Rafael; Sánchez-Recalde, Angel; Jiménez-Valero, Santiago; Galeote-Garcia, Guillermo; Moreno, Raúl

2014-10-01

Clinical trials have shown that functional assessment of coronary stenosis by fractional flow reserve (FFR) improves clinical outcomes. Intravascular ultrasound (IVUS) complements conventional angiography, and is a powerful tool to assess atherosclerotic plaques and to guide percutaneous coronary intervention (PCI). Computational fluid dynamics (CFD) simulation represents a novel method for the functional assessment of coronary flow. A CFD simulation can be calculated from the data normally acquired by IVUS images. A case of coronary heart disease studied with FFR and IVUS, before and after PCI, is presented. A three-dimensional model was constructed based on IVUS images, to which CFD was applied. A discussion of the literature concerning the clinical utility of CFD simulation is provided. Copyright © 2014 Sociedade Portuguesa de Cardiologia. Published by Elsevier España. All rights reserved.

Use of an intravascular fluorescent continuous glucose sensor in subjects with type 1 diabetes mellitus.

PubMed

Romey, Matthew; Jovanovič, Lois; Bevier, Wendy; Markova, Kateryna; Strasma, Paul; Zisser, Howard

2012-11-01

Stress hyperglycemia in the critically ill is associated with increased morbidity and mortality. Continuous glucose monitoring offers a solution to the difficulties of dosing intravenous insulin properly to maintain glycemic control. The purpose of this study was to evaluate an intravascular continuous glucose monitoring (IV-CGM) system with a sensing element based on the concept of quenched fluorescence. A second-generation intravascular continuous glucose sensor was evaluated in 13 volunteer subjects with type 1 diabetes mellitus. There were 21 study sessions of up to 24 h in duration. Sensors were inserted into peripheral veins of the upper extremity, up to two sensors per subject per study session. Sensor output was compared with temporally correlated reference measurements obtained from venous samples on a laboratory glucose analyzer. Data were obtained from 23 sensors in 13 study sessions with 942 paired reference values. Fourteen out of 23 sensors (60.9%) had a mean absolute relative difference ≤ 10%. Eighty-nine percent of paired points were in the clinically accurate A zone of the Clarke error grid and met ISO 15197 performance criteria. Adequate venous blood flow was identified as a necessary condition for accuracy when local sensor readings are compared with venous blood glucose. The IV-CGM system was capable of achieving a high level of glucose measurement accuracy. However, superficial peripheral veins may not provide adequate blood flow for reliable indwelling blood glucose monitoring. © 2012 Diabetes Technology Society.

Use of an Intravascular Fluorescent Continuous Glucose Sensor in Subjects with Type 1 Diabetes Mellitus

PubMed Central

Romey, Matthew; Jovanovič, Lois; Bevier, Wendy; Markova, Kateryna; Strasma, Paul; Zisser, Howard

2012-01-01

Background Stress hyperglycemia in the critically ill is associated with increased morbidity and mortality. Continuous glucose monitoring offers a solution to the difficulties of dosing intravenous insulin properly to maintain glycemic control. The purpose of this study was to evaluate an intravascular continuous glucose monitoring (IV-CGM) system with a sensing element based on the concept of quenched fluorescence. Method A second-generation intravascular continuous glucose sensor was evaluated in 13 volunteer subjects with type 1 diabetes mellitus. There were 21 study sessions of up to 24 h in duration. Sensors were inserted into peripheral veins of the upper extremity, up to two sensors per subject per study session. Sensor output was compared with temporally correlated reference measurements obtained from venous samples on a laboratory glucose analyzer. Results Data were obtained from 23 sensors in 13 study sessions with 942 paired reference values. Fourteen out of 23 sensors (60.9%) had a mean absolute relative difference ≤ 10%. Eighty-nine percent of paired points were in the clinically accurate A zone of the Clarke error grid and met ISO 15197 performance criteria. Adequate venous blood flow was identified as a necessary condition for accuracy when local sensor readings are compared with venous blood glucose. Conclusions The IV-CGM system was capable of achieving a high level of glucose measurement accuracy. However, superficial peripheral veins may not provide adequate blood flow for reliable indwelling blood glucose monitoring. PMID:23294770

Lipid detection by intravascular photoacoustic imaging with flexible catheter at 20 fps (Conference Presentation)

NASA Astrophysics Data System (ADS)

Wu, Min; Daeichin, Verya; Springeling, Geert; van der Steen, Antonius F. W.; van Soest, Gijs

2016-02-01

Intravascular Photoacoustic (IVPA) imaging is a promising new technology to assess lipid content of coronary atherosclerotic plaque, an important determinant of the risk associated with the plaque triggering a heart attack. Clinical translation of IVPA imaging requires real-time image acquisition, which has been a technological challenge. In this work, we demonstrate a high-speed, dual-wavelength IVPA imaging system at 1.7 µm wavelength, operating with a flexible catheter of 1.2 mm outer diameter (including outer sheath). The catheter was custom designed and fabricated, and used a 40 MHz transducer for intravascular ultrasound (IVUS) and IVPA imaging. The optical excitation is provided by a dual OPO system, pumped by CW diode-pumped Q-switched Nd:YAG lasers, with a repetition rate of 5 kHz. Each OPO can be tuned to a custom wavelength between 1690 and 1750 nm; two wavelengths only are needed to discriminate between plaque lipids and adipose tissue. The pulse energy is about 80 µJ. We tested the imaging performance of the presented system in a polyvinyl-alcohol (PVA) vessel mimicking phantom and human coronary arteries ex vivo. IVPA identified lipid deposits inside atherosclerotic plaque, while IVUS showed tissue structure. We demonstrated IVPA imaging at a speed of 20 frames per second, with 250 A-scans per frame. This is significantly faster than previous IVPA imaging systems, and will enable the translation of IVPA imaging into clinical practice.

Acute Increase in Hepatic Arterial Flow During TIPS Identified by Intravascular Flow Measurements

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

Radeleff, Boris, E-mail: Boris_Radeleff@med.uni-heidelberg.de; Sommer, Christof-Matthias; Heye, Tobias

2009-01-15

The purpose of this study was to investigate alterations of hepatic arterial flow during transjugular intrahepatic portosystemic stent shunt (TIPS) applying intravascular Doppler sonography. This prospective monocenter study included 25 patients with liver cirrhosis (alcohol induced [n = 19], chronic hepatitis associated [n = 3], primary biliary cirrhosis associated [n = 1], and cryptogenic [n = 2]) successfully treated with TIPS. All patients underwent intravascular hepatic arterial flow measurements during TIPS using an endoluminal flow sensor. The average arterial peak velocity (APV) and the maximum arterial peak velocity (MPV) were registered. Twenty-two patients (88%) showed increased APV, one patient (4%)more » showed unaffected APV, and two patients (8%) showed decreased APV after TIPS. The average portosystemic pressure gradient decreased significantly, from 22.0 {+-} 5.1 mmHg before TIPS to 11.0 {+-} 4.1 mmHg after TIPS (-50.0%; p < 0.0001). The average APV increased significantly, from 41.9 {+-} 17.8 cm/s before TIPS to 60.7 {+-} 19.0 cm/s after TIPS (+44.9%; p < 0.0001). The average MPV increased significantly, from 90.8 {+-} 31.7 cm/s before TIPS to 112.6 {+-} 34.9 cm/s after TIPS (+24.0%; p = 0.0002). These changes in perfusion set in within seconds after TIPS tract formation in all the patients with increased APV. We conclude that TIPS-induced portosystemic decompression leads to a significant increase in hepatic arterial flow. The changes occurred within seconds, suggesting a reflex-like mechanism.« less

An algorithm to correct 2D near-infrared fluorescence signals using 3D intravascular ultrasound architectural information

NASA Astrophysics Data System (ADS)

Mallas, Georgios; Brooks, Dana H.; Rosenthal, Amir; Vinegoni, Claudio; Calfon, Marcella A.; Razansky, R. Nika; Jaffer, Farouc A.; Ntziachristos, Vasilis

2011-03-01

Intravascular Near-Infrared Fluorescence (NIRF) imaging is a promising imaging modality to image vessel biology and high-risk plaques in vivo. We have developed a NIRF fiber optic catheter and have presented the ability to image atherosclerotic plaques in vivo, using appropriate NIR fluorescent probes. Our catheter consists of a 100/140 μm core/clad diameter housed in polyethylene tubing, emitting NIR laser light at a 90 degree angle compared to the fiber's axis. The system utilizes a rotational and a translational motor for true 2D imaging and operates in conjunction with a coaxial intravascular ultrasound (IVUS) device. IVUS datasets provide 3D images of the internal structure of arteries and are used in our system for anatomical mapping. Using the IVUS images, we are building an accurate hybrid fluorescence-IVUS data inversion scheme that takes into account photon propagation through the blood filled lumen. This hybrid imaging approach can then correct for the non-linear dependence of light intensity on the distance of the fluorescence region from the fiber tip, leading to quantitative imaging. The experimental and algorithmic developments will be presented and the effectiveness of the algorithm showcased with experimental results in both saline and blood-like preparations. The combined structural and molecular information obtained from these two imaging modalities are positioned to enable the accurate diagnosis of biologically high-risk atherosclerotic plaques in the coronary arteries that are responsible for heart attacks.

Cardiac variation of inferior vena cava: new concept in the evaluation of intravascular blood volume.

PubMed

Nakamura, Kensuke; Tomida, Makoto; Ando, Takehiro; Sen, Kon; Inokuchi, Ryota; Kobayashi, Etsuko; Nakajima, Susumu; Sakuma, Ichiro; Yahagi, Naoki

2013-07-01

Evaluation of the intravascular blood volume is an important assessment in emergency and critical care medicine. Measurement of the inferior vena cava (IVC) respiratory variation by ultrasound echography is useful, but it entails subjective problems. We have hypothesized that IVC cardiac variation is also correlated with intravascular blood volume and analyzed it automatically using computer software of two kinds, later comparing the results. Snakes, software to track boundaries by curve line continuity, and template matching software were incorporated into a computer with an ultrasound machine to track the short-axis view of IVC automatically and analyze it with approximation by ellipse. Eight healthy volunteers with temporary mild hypovolemia underwent echography before and after passive leg raising and while wearing medical anti-shock trousers. IVC cardiac variation was visually decreased by both leg raising and medical anti-shock trousers. The collapse index (maximum - minimum/maximum) of area during three cardiac beats was decreased showing a good relationship to fluid load simulations; 0.24 ± 0.03 at baseline versus 0.11 ± 0.01 with leg raising and 0.12 ± 0.01 with medical anti-shock trousers. In conclusion, IVC cardiac variation has the potential to provide an evaluation of water volume. It presents some advantages in mechanical analysis over respiratory variation. At the very least, we need to exercise some caution with cardiac variation when evaluating respiratory variation.

Identification of Mucosa-Invading and Intravascular Bacteria in Feline Small Intestinal Lymphoma.

PubMed

Hoehne, S N; McDonough, S P; Rishniw, M; Simpson, K W

2017-03-01

Persistent bacterial infections of the gastrointestinal mucosa are causally linked to gastric carcinoma and mucosa-associated lymphoid tissue (MALT) lymphoma in people and laboratory animals. We examined the relationship of mucosa-associated bacteria to alimentary lymphoma in cats. Intestinal biopsies from 50 cats with alimentary lymphoma (small cell, n = 33; large cell, n = 17) and 38 controls without lymphoma (normal to minimal change on histopathology, n = 18; lymphocytic-plasmacytic enteritis, n = 20) were evaluated. The number and spatial distribution of bacteria (ie, in luminal cellular debris, villus-associated mucus, adherent to epithelium, mucosal invasion, intravascular, or serosal) were determined by fluorescence in situ hybridization with the eubacterial probe EUB-338. Mucosa-invasive bacteria were more frequently observed in cats with large cell lymphoma (82%, P ≤ .001) than in cats with small cell lymphoma (18%), normal to minimal change on histopathology, and lymphocytic-plasmacytic enteritis (3%). Intravascular bacteria were observed solely in large cell lymphoma (29%), and serosal colonization was more common in cats with large cell lymphoma (57%) than with small cell lymphoma (11%, P ≤ .01), normal to minimal change (8%, P ≤ .01), and lymphocytic-plasmacytic enteritis (6%, P ≤ .001). The high frequency of invasive bacteria within blood vessels and serosa of cats with large cell lymphoma may account for the sepsis-related complications associated with large cell lymphoma and inform clinical management. Further studies are required to determine the role of intramucosal bacteria in the etiopathogenesis of feline alimentary lymphoma.

[Early onset pneumonia after successful resuscitation : Incidence after mild invasive hypothermia therapy].

PubMed

Erath, J W; Hodrius, J; Bushoven, P; Fichtlscherer, S; Zeiher, A M; Seeger, F H; Honold, J

2017-09-01

Targeted temperature management (TTM) represents an effective therapy to improve neurologic outcome in patients who survive an out-of-hospital cardiac arrest (OHCA). First publications about this therapy reported a higher incidence of infections in patients who underwent TTM induced by external cooling devices. Whether intravascular cooling devices are also associated with an increased infection rate has not been investigated so far. In a single center retrospective study, the incidence of early onset pneumonia (EOP) in OHCA patients with or without intravascular TTM at 33 °C target temperature for 24 h who survived at least 24 h after admission was analyzed. A total of 68 OHCA survivors (mean age 65 ± 15 years) were included in this analysis. The most common causes of OHCA were myocardial infarction (35 %), primary ventricular fibrillation (24 %), asystole (15 %), and pulmonary embolism (7 %). Of those, 32 patients (48 %) received TTM. The overall incidence of EOP was 38 %. Incidence of EOP did not differ significantly between groups, was more frequent in the group without TTM (42 % vs. 34 %, p = 0.57) and had no impact on mortality (hazard ratio = 1.02; 95 % confidence interval 0.25-4.16; p = 0.97). Intravascular TTM at 33 °C with a cooling catheter is not associated with more infective complications in OHCA patients. This finding underscores the safety of TTM.

Coagulation activation by MC28 fibrosarcoma cells facilitates lung tumor formation.

PubMed

Amirkhosravi, M; Francis, J L

1995-01-01

Tumor cells interact with the hemostatic system in various ways and may thus influence malignant growth and spread. MC28 fibrosarcoma cells possess a potent procoagulant activity (PCA) and form lung tumors following intravenous injection. The aim of this work was to study the relationship between PCA, intravascular coagulation and lung seeding in the MC28 model. MC28 cells were injected into control, warfarinized and heparinized hooded Lister rats. Coagulation changes were monitored by thromboelastography (TEG) and Sonoclot analysis (SA), lung fibrin formation by light and electron microscopy, tumor seeding by macroscopic counting and tumor cell and platelet deposition in the lungs by radiolabelling. PCA was measured by chromogenic assay. MC28 PCA was characterized as a tissue factor-factor VIIa complex that probably arose during cell culture or disaggregation of solid tumors. Injection of tumor cells caused marked coagulopathy and was rapidly (within 30 min) followed by fibrin deposition in the lungs and accumulation of radiolabelled platelets. Heparin and warfarin significantly reduced lung seeding (p < 0.001) and reduced retention of radiolabelled tumor cells in the pulmonary circulation (p < 0.01). Inhibition of cellular PCA by prior treatment with concanavalin A markedly reduced intravascular coagulation and lung seeding. We conclude that MC28 cells cause intravascular coagulation as a direct result of their procoagulant activity. The data suggest that tumor cells form complexes with platelets and fibrin which are retained in the lungs long enough for extravasation and seeding to occur.(ABSTRACT TRUNCATED AT 250 WORDS)

Equine Piroplasmosis

USDA-ARS?s Scientific Manuscript database

Equine piroplasmosis is an infectious, tick-borne disease caused by the hemoprotozoan parasites Theileria (previously Babesia) equi and Babesia caballi. Piroplasmosis affects all wild and domestic equid species and causes signs related to intravascular hemolysis and associated systemic illness. Infe...

[Candida sp endocarditis. Experience in a third-level hospital and review of the literature].

PubMed

Hernández-Torres, Alicia; García-Vázquez, Elisa; Laso-Ortiz, Alicia; Herrero-Martínez, José Antonio; Gómez-Gómez, Joaquín

2013-03-01

Despite the relative high frequency of Candida bloodstream infection, Candida endocarditis is a rare entity. We report five cases of Candida endocarditis admitted to our hospital in the period between 2005 and 2011. Two cases were caused by C. albicans, two cases were caused by C. parapsilosis and in the last one, we didn't identify the species of Candida. All but one had clear risk factors for candidemia. Treatment consisted of amphotericin B with / without flucytosine in four patients, and they all underwent surgery for valve replacement and / or removal of intravascular devices. Overall mortality was 60% (40% of mortality was directly related to endocarditis). All patients who survived were given suppressive therapy with fluconazole for a minimum of two years.After stopping fluconazole there was a case of recurrence.

A new gas lesion syndrome in man, induced by 'isobaric gas counterdiffusion'

NASA Technical Reports Server (NTRS)

Lambertsen, C. J.; Idicula, J.

1975-01-01

Normal men have been found to develop pruritis and gas bubble lesions in the skin, and disruption of vestibular function, when breathing nitrogen or neon with oxygen while surrounded by helium at increased ambient pressure. This phenomenon, which occurs at stable ambient pressures, at 1 or many ATA, has been designated the isobaric gas counterdiffusion syndrome. In a series of analyses and experiments in vivo and in vitro the cause of the syndrome has been established as due to gas accumulation and development of gas bubbles in tissues as a result of differences in selective diffusivities, for various respired and ambient gases, in the tissue substances between capillary blood and the surrounding atmosphere. The phenomenon described in man is an initial stage of a process shown later in animals to progress to continuous, massive, lethal, intravascular gas embolization.

Integrated intravascular ultrasound and optical coherence tomography technology: a promising tool to identify vulnerable plaques [INVITED PAPER

PubMed Central

Li, Jiawen; Chen, Zhongping

2017-01-01

Heart attack is mainly caused by the rupture of a vulnerable plaque. IVUS-OCT is a novel medical imaging modality that provides opportunities for accurate assessment of vulnerable plaques in vivo in patients. IVUS provides deep penetration to image the whole necrotic core while OCT enables accurate measurement of the fibrous cap of a plaque owing to its high resolution. In this paper, the authors describe the fundamentals, the technical designs and the applications of IVUS-OCT technology. Results from cadaver specimens are summarized, which indicated the complementary nature of OCT and IVUS for assessment of vulnerable plaques, plaque composition, and stent-tissue interactions. Furthermore, previously reported in vivo animal experiments are reviewed to assess the clinical adaptability of IVUS-OCT. Future directions for this technology are also discussed in this review. PMID:28966987

Coronary Artery Dissection: Not Just a Heart Attack

MedlinePlus

... using an angiogram , but an intravascular ultrasound or optical coherence tomography screening, which allows doctors to see ... Changes Recovery FAQs • Heart Attack Tools & Resources • Support Network Watch, Learn and Live Our Interactive Cardiovascular Library ...

A state-of-the-art review on segmentation algorithms in intravascular ultrasound (IVUS) images.

PubMed

Katouzian, Amin; Angelini, Elsa D; Carlier, Stéphane G; Suri, Jasjit S; Navab, Nassir; Laine, Andrew F

2012-09-01

Over the past two decades, intravascular ultrasound (IVUS) image segmentation has remained a challenge for researchers while the use of this imaging modality is rapidly growing in catheterization procedures and in research studies. IVUS provides cross-sectional grayscale images of the arterial wall and the extent of atherosclerotic plaques with high spatial resolution in real time. In this paper, we review recently developed image processing methods for the detection of media-adventitia and luminal borders in IVUS images acquired with different transducers operating at frequencies ranging from 20 to 45 MHz. We discuss methodological challenges, lack of diversity in reported datasets, and weaknesses of quantification metrics that make IVUS segmentation still an open problem despite all efforts. In conclusion, we call for a common reference database, validation metrics, and ground-truth definition with which new and existing algorithms could be benchmarked.

Intravascular Optical Imaging Technology for Investigating the Coronary Artery

PubMed Central

Suter, Melissa J.; Nadkarni, Seemantini K.; Weisz, Giora; Tanaka, Atsushi; Jaffer, Farouc A.; Bouma, Brett E.; Tearney, Guillermo J.

2012-01-01

There is an ever-increasing demand for new imaging methods that can provide additional information about the coronary wall to better characterize and stratify high-risk plaques, and to guide interventional and pharmacologic management of patients with coronary artery disease. While there are a number of imaging modalities that facilitate the assessment of coronary artery pathology, this review paper focuses on intravascular optical imaging modalities that provide information on the microstructural, compositional, biochemical, biomechanical, and molecular features of coronary lesions and stents. The optical imaging modalities discussed include angioscopy, optical coherence tomography, polarization sensitive-optical coherence tomography, laser speckle imaging, near-infrared spectroscopy, time-resolved laser induced fluorescence spectroscopy, Raman spectroscopy, and near-infrared fluorescence molecular imaging. Given the wealth of information that these techniques can provide, optical imaging modalities are poised to play an increasingly significant role in the evaluation of the coronary artery in the future. PMID:21920342

Neonatal Plasma Transfusion: An Evidence-Based Review.

PubMed

Keir, Amy K; Stanworth, Simon J

2016-10-01

Several clinical scenarios for plasma transfusion are repeatedly identified in audits, including treatment of bleeding in association with laboratory evidence of coagulopathy, correction of disseminated intravascular coagulation, prevention of intraventricular hemorrhage, management of critically ill neonates (eg, during sepsis or as a volume expander), or correction of markers of prolonged coagulation in the absence of bleeding. The findings of at least one national audit of transfusion practice indicated that almost half of plasma transfusions are given to neonates with abnormal coagulation values with no evidence of active bleeding, despite the limited evidence base to support the effectiveness of this practice. Plasma transfusions to neonates should be considered in the clinical context of bleeding (eg, vitamin K dependent), disseminated intravascular coagulation, and very rare inherited deficiencies of coagulation factors. There seems to be no role for prophylactic plasma to prevent intraventricular hemorrhage or for use as a volume expander. Copyright © 2016 Elsevier Inc. All rights reserved.

Cardiovascular Adjustments to Gravitational Stress

NASA Technical Reports Server (NTRS)

Blomqvist, C. Gunnar; Stone, H. Lowell

1991-01-01

The effects of gravity on the cardiovascular system must be taken into account whenever a hemodynamic assessment is made. All intravascular pressure have a gravity-dependent hydrostatic component. The interaction between the gravitational field, the position of the body, and the functional characteristics of the blood vessels determines the distribution of intravascular volume. In turn this distribution largely determines cardiac pump function. Multiple control mechanisms are activated to preserve optimal tissue perfusion when the magnitude of the gravitational field or its direction relative to the body changes. Humans are particularly sensitive to such changes because of the combination of their normally erect posture and the large body mass and blood volume below the level of the heart. Current aerospace technology also exposes human subjects to extreme variations in the gravitational forces that range from zero during space travel to as much an nine-times normal during operation of high-performance military aircraft. This chapter therefore emphasizes human physiology.

A new device for intraoperative renal blood flow measurement during open-heart surgery: an experimental study and the clinical pilot study.

PubMed

Tirilomis, Theodor; Popov, Aron F; Hanekop, Gunnar G; Braeuer, Anselm; Quintel, Michael; Schoendube, Friedrich A; Friedrich, Martin G

2013-10-01

Renal blood flow (RBF) may vary during cardiopulmonary bypass and low flow may cause insufficient blood supply of the kidney triggering renal failure postoperatively. Still, a valid intraoperative method of continuous RBF measurement is not available. A new catheter combining thermodilution and intravascular Doppler was developed, first calibrated in an in vitro model, and the catheter specific constant was determined. Then, application of the device was evaluated in a pilot study in an adult cardiovascular population. The data of the clinical pilot study revealed high correlation between the flow velocities detected by intravascular Doppler and the RBF measured by thermodilution (Pearson's correlation range: 0.78 to 0.97). In conclusion, the RBF can be measured excellently in real time using the new catheter, even under cardiopulmonary bypass. © 2013 Wiley Periodicals, Inc. and International Center for Artificial Organs and Transplantation.

Monte Carol-Based Dosimetry of Beta-Emitters for Intravascular Brachytherapy

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

Choi, C.K.

2002-06-25

Monte Carlo simulations for radiation dosimetry and the experimental verifications of the simulations have been developed for the treatment geometry of intravascular brachytherapy, a form of radionuclide therapy for occluded coronary disease (restenosis). Monte Carlo code, MCNP4C, has been used to calculate the radiation dose from the encapsulated array of B-emitting seeds (Sr/Y-source train). Solid water phantoms have been fabricated to measure the dose on the radiochromic films that were exposed to the beta source train for both linear and curved coronary vessel geometries. While the dose difference for the 5-degree curved vessel at the prescription point of f+2.0 mmmore » is within the 10% guideline set by the AAPM, however, the difference increased dramatically to 16.85% for the 10-degree case which requires additional adjustment for the acceptable dosimetry planning. The experimental dose measurements agree well with the simulation results« less

Utility of Functional Hemodynamics and Echocardiography to Aid Diagnosis and Management of Shock.

PubMed

McGee, William T; Raghunathan, Karthik; Adler, Adam C

2015-12-01

The utility of functional hemodynamics and bedside ultrasonography is increasingly recognized as advantageous for both improved diagnosis and management of shock states. In contrast to conventional "static" measures, "dynamic" hemodynamic measures and bedside imaging modalities enhance pathophysiology-based comprehensive understanding of shock states and the response to therapy. The current editions of major textbooks in the primary specialties--in which clinicians routinely encounter patients in shock--including surgery, anesthesia, emergency medicine, and internal medicine continue to incorporate traditional (conventional) descriptions of shock that use well-described (but potentially misleading) intravascular pressures to classify shock states. Reliance on such intravascular pressure measurements is not as helpful as newer "dynamic" functional measures including ultrasonography to both better assess volume responsiveness and biventricular cardiac function. This review thus emphasizes the application of current functional hemodynamics and ultrasonography to the diagnosis and management of shock as a contrast to conventional "static" pressure-based measures.

Foot-strike haemolysis in an ultramarathon runner.

PubMed

Fazal, Abid A; Whittemore, Mary S; DeGeorge, Katharine C

2017-12-13

This case report describes mild anaemia and intravascular haemolysis in an otherwise healthy 41-year-old ultramarathon runner. In long-distance endurance athletes, trace gastrointestinal bleeding and plasma volume expansion are recognised sources of mild anaemia, often found incidentally. However, repetitive forceful foot striking can lead to blood cell lysis in the feet, resulting in a mild macrocytic anaemia and intravascular haemolysis, as was demonstrated in the patient described herein. Mild anaemia in runners, often called 'runner's pseudoanaemia', is typically clinically insignificant and does not require intervention. However, an unexplained anaemia can cause undue worry for otherwise healthy patients and lead to costly further testing, providing an argument against routine testing with complete blood counts in healthy, asymptomatic patients. © BMJ Publishing Group Ltd (unless otherwise stated in the text of the article) 2017. All rights reserved. No commercial use is permitted unless otherwise expressly granted.

Hemodynamic and intravascular ultrasound assessment of myocardial bridging: fractional flow reserve paradox with dobutamine versus adenosine.

PubMed

Hakeem, Abdul; Cilingiroglu, Mehmet; Leesar, Massoud A

2010-02-01

Compared to coronary angiography, both intravascular ultrasound (IVUS) and CT-angiography provide important information with respect to the morphological aspects of myocardial bridging (MB). However, these modalities are limited in defining the hemodynamic and clinical significance of MB. Intracoronary Doppler studies demonstrate a peculiar abnormal Doppler flow profile associated with MB. Fractional flow reserve (FFR) after adenosine infusion has been used to assess the hemodynamic significance of MB, but FFR after adenosine induced hyperemia underestimates the significance of MB. On the other hand, high-dose dobutamine by increasing the contractility of the bridging segment unmasks ischemia induced by MB. This review outlines the role of flow velocity measurement by intracoronary Doppler, FFR, and IVUS for assessment of patients with MB. In addition, we compared FFR measurements after adenosine versus dobutamine infusions for the hemodynamic assessment of MB in two patients.

D-dimer: An Overview of Hemostasis and Fibrinolysis, Assays, and Clinical Applications.

PubMed

Olson, John D

2015-01-01

D-dimer is the smallest fibrinolysis-specific degradation product found in the circulation. The origins, assays, and clinical use of D-dimer will be addressed. Hemostasis (platelet and vascular function, coagulation, fibrinolysis, hemostasis) is briefly reviewed. D-dimer assays are reviewed. The D-dimer is very sensitive to intravascular thrombus and may be markedly elevated in disseminated intravascular coagulation, acute aortic dissection, and pulmonary embolus. Because of its exquisite sensitivity, negative tests are useful in the exclusion venous thromboembolism. Elevations occur in normal pregnancy, rising two- to fourfold by delivery. D-dimer also rises with age, limiting its use in those >80 years old. There is a variable rise in D-dimer in active malignancy and indicates increased thrombosis risk in active disease. Elevated D-dimer following anticoagulation for a thrombotic event indicates increased risk of recurrent thrombosis. These and other issues are addressed. © 2015 Elsevier Inc. All rights reserved.

Endovascular retrieval of dental needle retained in the internal carotid artery.

PubMed

Moore, Kenneth; Khan, Nickalus R; Michael, L Madison; Arthur, Adam S; Hoit, Daniel

2017-07-01

Intravascular foreign bodies are a known complication of medical and dental procedures. Dental anesthetic needles may be broken off and retained in the oropharynx. These needles have occasionally been reported to migrate through the oral mucosa in to deeper structures. Here we present the case of a 57-year-old man who had a retained dental needle that had migrated into his internal carotid artery. The needle was removed using endovascular techniques. To our knowledge, this is the first report of a retained dental needle being retrieved using this method. We review the literature on intravascular foreign bodies, retained dental needles, and endovascular techniques for retrieval of such foreign bodies. 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/.

Linear-regression convolutional neural network for fully automated coronary lumen segmentation in intravascular optical coherence tomography

NASA Astrophysics Data System (ADS)

Yong, Yan Ling; Tan, Li Kuo; McLaughlin, Robert A.; Chee, Kok Han; Liew, Yih Miin

2017-12-01

Intravascular optical coherence tomography (OCT) is an optical imaging modality commonly used in the assessment of coronary artery diseases during percutaneous coronary intervention. Manual segmentation to assess luminal stenosis from OCT pullback scans is challenging and time consuming. We propose a linear-regression convolutional neural network to automatically perform vessel lumen segmentation, parameterized in terms of radial distances from the catheter centroid in polar space. Benchmarked against gold-standard manual segmentation, our proposed algorithm achieves average locational accuracy of the vessel wall of 22 microns, and 0.985 and 0.970 in Dice coefficient and Jaccard similarity index, respectively. The average absolute error of luminal area estimation is 1.38%. The processing rate is 40.6 ms per image, suggesting the potential to be incorporated into a clinical workflow and to provide quantitative assessment of vessel lumen in an intraoperative time frame.

Dual-frequency ultrasound for detecting and sizing bubbles.

PubMed

Buckey, Jay C; Knaus, Darin A; Alvarenga, Donna L; Kenton, Marc A; Magari, Patrick J

2005-01-01

ISS construction and Mars exploration require extensive extravehicular activity (EVA), exposing crewmembers to increased decompression sickness risk. Improved bubble detection technologies could help increase EVA efficiency and safety. Creare Inc. has developed a bubble detection and sizing instrument using dual-frequency ultrasound. The device emits "pump" and "image" signals at two frequencies. The low-frequency pump signal causes an appropriately-sized bubble to resonate. When the image frequency hits a resonating bubble, mixing signals are returned at the sum and difference of the two frequencies. To test the feasibility of transcutaneous intravascular detection, intravascular bubbles in anesthetized swine were produced using agitated saline and decompression stress. Ultrasonic transducers on the chest provided the two frequencies. Mixing signals were detected transthoracically in the right atrium using both methods. A histogram of estimated bubble sizes could be constructed. Bubbles can be detected and sized transthoracically in the right atrium using dual-frequency ultrasound. c2005 Elsevier Ltd. All rights reserved.

Effective Immunotherapy in Bone Marrow Metastatic Melanoma Presenting with Disseminated Intravascular Coagulopathy.

PubMed

Gbadamosi, Bolanle; Ezekwudo, Daniel; Nayak, Bhadresh; Yu, Zhou; Gjorgova-Gjeorgjievski, Sandra; Xie, Ming; Robert, Colvin; Jaiyesimi, Ishmael; Huben, Marianne

2018-01-01

Malignant melanoma is responsible for the majority of skin cancer deaths and is increasing in prevalence. Bone marrow (BM) involvement by melanoma is rare in the absence of widespread visceral disease. Here, we report the case of a 30-year-old female who presented to the hospital with back pain, low-grade fever, and easy bruising. She was found to be bicytopenic and in disseminated intravascular coagulopathy (DIC). Surprisingly, BM biopsy showed extensive involvement by metastatic malignant melanoma in the absence of visceral or brain metastasis. The unique presentation of this case and the challenge of management of a potentially treatable cancer in a critically ill patient are discussed, alongside a review of published cases of metastatic melanoma in the BM and an exploration of currently available treatment options. The excellent response of our patient to combined immune checkpoint inhibitors has yet to be paralleled in the available literature.

Intravascular ultrasound and angiographic demonstration of left main stem thrombus-high-risk presentation in a young adult with anabolic steroid abuse.

PubMed

Garg, Pankaj; Davis, Gershan; Wilson, John Ian; Sivananthan, Mohan

2010-01-01

We present a case of acute myocardial infarction in a young adult with a history of anabolic steroid abuse. On diagnostic coronary angiography and intravascular ultrasound, he was found to have a distal left main stem thrombus extending into the proximal left anterior descending artery and a large intermediate vessel. As he was hemodynamically stable and pain-free, he was managed conservatively with triple antiplatelet therapy (aspirin, clopidogrel, and abciximab). This was also to avoid the risk of 'wiring the vessel,' especially if there was underlying dissection. Repeat angiography a few weeks later showed complete thrombus resolution. This is the first reported case of extensive left main stem thrombus in a young patient with anabolic steroid abuse. Management of such cases is not straightforward and our case highlights one approach to both diagnosis and treatment.

Risk of disseminated intravascular coagulation in patients with type 2 diabetes mellitus: retrospective cohort study

PubMed Central

Nogami, Kenichiro; Muraki, Isao; Imano, Hironori; Iso, Hiroyasu

2017-01-01

Objectives To determine quantitatively the association between type 2 diabetes mellitus (T2DM) and disseminated intravascular coagulation (DIC). Design Retrospective cohort study using a claims database. Setting Medical care institutions representing 9% of all secondary hospitals (acute care hospitals) in Japan. Participants In total, 797 324 admissions, comprising 435 354 patients aged 18–79 years at the time of admission, were enrolled between January 2010 and September 2014. All patients were diagnosed with diabetes or admitted to hospitals that provided laboratory data. Main outcome measures Incidence of DIC reported by physicians in claims data. Results Logistic regression analysis found that the risk of DIC was significantly higher in T2DM patients than in non-DM patients (fully adjusted OR: 1.39 (95% CI 1.32 to 1.45)), independent of age, sex, admission year and potential underlying diseases. The higher risk of DIC in T2DM patients was apparent in those who were treated with insulin within the 30-day period prior to admission (1.53 (1.37 to 1.72)). When stratified by the potential underlying diseases, the risk of DIC was higher in T2DM patients with non-septic severe infection (1.67 (1.41 to 1.97)) and with solid tumour (1.59 (1.47 to 1.72)) than in non-DM patients with those underlying diseases. The risk was similar between T2DM and non-DM patients with sepsis (0.98 (0.90 to 1.08)) and lower in T2DM patients with acute leukaemia (0.70 (0.59 to 0.84)). Conclusions T2DM was associated with a higher risk of DIC, particularly when recently treated with insulin, as well as among admissions with solid tumour or non-septic severe infection. PMID:28122835

Effects of long-term head-down-tilt bed rest and different training regimes on the coagulation system of healthy men

PubMed Central

Haider, Thomas; Gunga, Hanns-Christian; Matteucci-Gothe, Raffaella; Sottara, Elke; Griesmacher, Andrea; Belavý, Daniel L; Felsenberg, Dieter; Werner, Andreas; Schobersberger, Wolfgang

2013-01-01

Immobility plus preexisting chronic disease or acute trauma can activate the coagulation system, thus increasing the risk for thromboembolic events. The effects of long-term bed-rest immobility and microgravity on the coagulation system of healthy persons (e.g., during crewed Mars missions) have not yet been studied. The main objective of the second Berlin BedRest Study (BBR2-2) “Coagulation Part” was to investigate adaptations of the hemostatic system during long-term bed rest (60 days) under simulated microgravity (6° head-down-tilt [6°HDT]) and after mobilization in three different volunteer groups (randomly assigned to CTR= inactive control group; RE= resistive exercise only group; and RVE= resistive exercise with whole-body vibration group). In 24 males (aged 21–45 years), before, during, and after long-term bed rest, key parameters of coagulation were measured from venous blood samples: D-dimer (DD), thrombin–antithrombin III complex (TAT), and prothrombin fragment F1 + 2 (PT-F1 + 2). Additionally, modified rotational thrombelastometry (ROTEM®) analysis was performed. Times of exploratory analyses were as follows: baseline data collection 2 days before bed rest (BDC-2); eight different days of 6°HDT bed rest (HDT1–HDT60), and two different days after reambulation (R + 3 and R + 6). We found significant changes in DD, TAT, and PT-F1 + 2 over the total time course, but no consistent effect of physical interventions (RE, RVE) on these parameters. Notably, no parameter reached levels indicative of intravascular thrombin formation. All ROTEM® parameters remained within the normal range and no pathological traces were found. Sixty days of 6°HDT bed rest are not associated with pronounced activation of the coagulation system indicative of intravascular thrombus formation in healthy volunteers independent of the training type during the bed rest. PMID:24400137

Cyanoacrylate tissue adhesives - effective securement technique for intravascular catheters: in vitro testing of safety and feasibility.

PubMed

Simonova, G; Rickard, C M; Dunster, K R; Smyth, D J; McMillan, D; Fraser, J F

2012-05-01

Partial or complete dislodgement of intravascular catheters remains a significant problem in hospitals despite current securement methods. Cyanoacrylate tissue adhesives (TA) are used to close skin wounds as an alternative to sutures. These adhesives have high mechanical strength and can remain in situ for several days. This study investigated in vitro use of TAs in securing intravascular catheters (IVC). We compared two adhesives for interaction with IVC material, comparing skin glues with current securement methods in terms of their ability to prevent IVC dislodgement and inhibit microbial growth. Two TAs (Dermabond, Ethicon Inc. and Histoacryl, B. Braun) and three removal agents (Remove™, paraffin and acetone) were tested for interaction with IVC material by use of tensile testing. TAs were also compared against two polyurethane (standard and bordered) dressings (Tegaderm™ 1624 and 1633, 3M Australia Pty Ltd) and an external stabilisation device (Statlock, Bard Medical, Covington) against control (unsecured IVCs) for ability to prevent pull-out of 16 G peripheral IVCs from newborn fresh porcine skin. Agar media containing pH-sensitive dye was used to assess antimicrobial properties of TAs and polyurethane dressings to inhibit growth of Staphylococcus aureus and Staphylococcus epidermidis. Neither TA weakened the IVCs (P >0.05). Of removal agents, only acetone was associated with a significant decrease in IVC strength (P <0.05). Both TAs and Statlock significantly increased the pull-out force (P <0.01). TA was quick and easy to apply to IVCs, with no irritation or skin damage noted on removal and no bacterial colony growth under either TA.

Catastrophic antiphospholipid syndrome: a clinical review.

PubMed

Nayer, Ali; Ortega, Luis M

2014-01-01

Catastrophic antiphospholipid syndrome (CAPS) is a rare life-threatening autoimmune disease characterized by disseminated intravascular thrombosis resulting in multiorgan failure. Directory of Open Access Journals (DOAJ), Google Scholar, PubMed (NLM), LISTA (EBSCO) and Web of Science have been searched. CAPS is due to antiphospholipid antibodies directed against a heterogeneous group of proteins that are associated with phospholipids. These autoantibodies activate endothelial cells, platelets, and immune cells, thereby promoting a proinflammatory and prothrombotic phenotype. Furthermore, antiphospholipid antibodies inhibit anticoagulants, impair fibrinolysis, and activate complements. Although CAPS can affect a variety of organs and tissues, the kidneys, lungs, central nervous system, heart, skin, liver, and gastrointestinal tract are most commonly affected. The systemic inflammatory response syndrome, likely to extensive tissue damage, accompanies CAPS. The most frequent renal manifestations are hypertension, proteinuria, hematuria, and acute renal failure.In the majority of patients with CAPS, a precipitating factor such as infection, surgery, or medication can be identified. Antiphospholipid antibodies such as lupus anticoagulant and antibodies against cardiolipin, β2-glycoprotein I, and prothrombin are serological hallmark of CAPS. Laboratory tests often reveal antinuclear antibodies, thrombocytopenia, and anemia. Despite widespread intravascular coagulation, blood films reveal only a small number of schistocytes. In addition, severe thrombocytopenia is uncommon. Histologically, CAPS is characterized by acute thrombotic microangiopathy. CAPS must be distinguished from other forms of thrombotic microangiopathies such as hemolytic-uremic syndrome, thrombotic thrombocytopenic purpura, disseminated intravascular coagulation, and heparin-induced thrombocyt openia. CAPS is associated with high morbidity and mortality. Therefore, an aggressive multidisciplinary treatment strategy is indicated. Anticoagulation, immunosuppression, plasma exchange, intravenous immunoglobulins, and anti-platelet agents, used in various combinations, have resulted in improved patient outcome.

Use of an Intravascular Fluorescent Continuous Glucose Sensor in ICU Patients.

PubMed

Strasma, Paul J; Finfer, Simon; Flower, Oliver; Hipszer, Brian; Kosiborod, Mikhail; Macken, Lewis; Sechterberger, Marjolein; van der Voort, Peter H J; DeVries, J Hans; Joseph, Jeffrey I

2015-07-01

Hyperglycemia and hypoglycemia are associated with adverse clinical outcomes in intensive care patients. In product development studies at 4 ICUs, the safety and performance of an intravascular continuous glucose monitoring (IV-CGM) system was evaluated in 70 postsurgical patients. The GluCath System (GluMetrics, Inc) used a quenched chemical fluorescence mechanism to optically measure blood glucose when deployed via a radial artery catheter or directly into a peripheral vein. Periodic ultrasound assessed blood flow and thrombus formation. Patient glucose levels were managed according to the standard of care and existing protocols at each site. Reference blood samples were acquired hourly and compared against prospectively calibrated sensor results. In all, 63 arterial sensors and 9 venous sensors were deployed in 70 patients. Arterial sensors did not interfere with invasive blood pressure monitoring, sampling or other aspects of patient care. A majority of venous sensors (66%) exhibited thrombus on ultrasound. In all, 89.4% (1383/1547) of arterial and 72.2% (182/252) of venous measurements met ISO15197:2003 criteria (within 20%), and 72.7% (1124/1547) of arterial and 56.3% (142/252) of venous measurements met CLSI POCT 12-A3 criteria (within 12.5%). The aggregate mean absolute relative difference (MARD) between the sensors and the reference was 9.6% for arterial and 14.2% for venous sensors. The GluCath System exhibited acceptable accuracy when deployed in a radial artery for up to 48 hours in ICU patients after elective cardiac surgery. Accuracy of venous deployment was substantially lower with significant rates of intravascular thrombus observed using ultrasound. © 2015 Diabetes Technology Society.

Detection and characterization of atherosclerotic plaques by Raman probe spectroscopy and optical coherence tomography (Conference Presentation)

NASA Astrophysics Data System (ADS)

Matthäus, Christian; Dochow, Sebastian; Egodage, Kokila D.; Schie, Iwan; Romeike, Bernd F.; Brehm, Bernhard R.; Popp, Jürgen

2017-02-01

Visualization and characterization of inner arterial plaque depositions is of vital diagnostic interest. Established intravascular imaging techniques provide valuable morphological information, but cannot deliver information about the chemical composition of individual plaques. Probe based Raman spectroscopy offers the possibility for a biochemical characterization of atherosclerotic plaque formations during an intravascular intervention. From post mortem studies it is well known that the severity of a plaque and its stability are strongly correlated with its biochemical composition. Especially the identification of vulnerable plaques remains one of the most important and challenging aspects in cardiology. Thus, specific information about the composition of a plaque would greatly improve the risk assessment and management. Furthermore, knowledge about the composition can offer new therapeutic and medication strategies. Plaque calcifications as well as major lipid components such as cholesterol, cholesterol esters and triglycerides can be spectroscopically easily differentiated. Intravascular optical coherence tomography (OCT) is currently a prominent catheter based imaging technique for the localization and visualization of atherosclerotic plaque depositions. The high resolution of OCT with 10 to 15 µm allows for very detailed characterization of morphological features such as different plaque formations, thin fibrous caps and accurate measurements of lesion lengths. In combination with OCT imaging the obtained spectral information can provide substantial information supporting on on-site diagnosis of various plaque types and therefor an improved risk assessment. The potential and feasibility of combining OCT with Raman spectroscopy is demonstrated on excised plaque samples, as well as under in vivo conditions. Acknowledgements: Financial support from the Carl Zeiss Foundation is greatly acknowledged.

Toward intravascular morphological and biochemical imaging of atherosclerosis with optical coherence tomography (OCT) and fluorescence lifetime imaging (FLIM) (Conference Presentation)

NASA Astrophysics Data System (ADS)

Chen, Xi; Kim, Wihan; Serafino, Michael; Walton, Brian; Jo, Javier A.; Applegate, Brian E.

2017-02-01

We have shown in an ex vivo human coronary artery study that the biochemical information derived from FLIM interpreted in the context of the morphological information from OCT enables a detailed classification of human coronary plaques associated with atherosclerosis. The identification of lipid-rich plaques prone to erosion or rupture and associated with sudden coronary events can impact current clinical practice as well as future development of targeted therapies for "vulnerable" plaques. In order to realize clinical translation of intravascular OCT/FLIM we have had to develop several key technologies. A multimodal catheter endoscope capable of delivering near UV excitation for FLIM and shortwave IR for OCT has been fabricated using a ball lens design with a double clad fiber. The OCT illumination and the FLIM excitation propogate down the inner core while the large outer multimode core captures the fluorescence emission. To enable intravascular pullback imaging with this endoscope we have developed an ultra-wideband fiber optic rotary joint using the same double clad fiber. The rotary joint is based on a lensless design where two cleaved fibers, one fixed and one rotating, are brought into close proximity but not touching. Using water as the lubricant enabled operation over the near UV-shortwave IR range. Transmission over this bandwidth has been measured to be near 100% at rotational frequencies up to 147 Hz. The entire system has been assembled and placed on a mobile cart suitable for cath lab based imaging. System development, performance, and early ex vivo imaging results will be discussed.

Inhaled nitrite reverses hemolysis-induced pulmonary vasoconstriction in newborn lambs without blood participation

PubMed Central

Blood, Arlin B.; Schroeder, Hobe J.; Terry, Michael H.; Merrill-Henry, Jeanette; Bragg, Shannon L.; Vrancken, Kurt; Liu, Taiming; Herring, Jason L.; Sowers, Lawrence C.; Wilson, Sean M.; Power, Gordon G.

2011-01-01

Background Nitrite can be converted to nitric oxide (NO) by a number of different biochemical pathways. In newborn lambs an aerosol of inhaled nitrite has been found to reduce pulmonary blood pressure, possibly acting via conversion to NO by reaction with intraerythrocytic deoxyhemoglobin. If so, the vasodilating effects of nitrite would be attenuated by free hemoglobin in plasma that would rapidly scavenge NO. Methods and Results Pulmonary vascular pressures and resistances to flow were measured in anesthetized newborn lambs. Plasma hemoglobin concentrations were then elevated, resulting in marked pulmonary hypertension. This effect was attenuated if infused hemoglobin was first oxidized to methemoglobin which does not scavenge NO. These results further implicate NO as a tonic pulmonary vasodilator. Next, while free hemoglobin continued to be infused, the lambs were given inhaled NO gas (20 ppm), inhaled sodium nitrite aerosol (0.87 M), or an intravascular nitrite infusion (3 mg·hr−1 bolus, 5 mg·kg−1·hr−1 infusion). Inhaled NO and inhaled nitrite aerosol both resulted in pulmonary vasodilation. Intravascular infusion of nitrite, however, did not. Increases in exhaled NO gas were observed while breathing the nitrite aerosol (~20 ppb NO) but not during intravascular infusion of nitrite. Conclusions We conclude that the pulmonary vasodilating effect of inhaled nitrite results from its conversion to NO in airway and parenchymal lung tissue and is not dependent on reactions with deoxyhemoglobin in the pulmonary circulation. Inhaled nitrite aerosol remains a promising candidate to reduce pulmonary hypertension in clinical application. PMID:21282501

Splinter haemorrhages, Osler's nodes, Janeway lesions and Roth spots: the peripheral stigmata of endocarditis.

PubMed

Sethi, Karishma; Buckley, Jim; de Wolff, Jacob

2013-09-01

Infective endocarditis is a serious endo-vascular infection, potentially affecting not only native heart valves, but also intra-vascularly implanted foreign materials such as valvular prostheses and pacemaker electrodes (Westphal et al, 2009).

Intravascular flow detection during transforaminal epidural injections: a prospective assessment.

PubMed

El Abd, Omar Hamman; Amadera, Joao Eduardo Daud; Pimentel, Daniel Camargo; Pimentel, Thais Spacov Camargo

2014-01-01

Transforaminal epidural steroid injections (TFESI) are a mainstay in the treatment of spine pain. Though this commonly performed procedure is generally felt to be safe, devastating complications following inadvertent intra-arterial injections of particulate steroid have been reported. The use of digital subtraction angiography (DSA) has been suggested as a means of detecting intra-arterial needle placements prior to medication injection. To examine the efficacy of DSA in detecting intra-arterial needle placements during TFESI. Prospective cohort study evaluating the impact of DSA on detecting intra-arterial needle placements during TFESI. We enrolled 150 consecutive patients presenting to a university-affiliated spine center with discogenic and/or radicular symptoms affecting the cervical, lumbar, and sacral regions. For each injection, prior to imaging with DSA, traditional methods for vascular penetration detection were employed, including the identification of blood in the needle hub (flash), negative aspiration of blood prior to injection, and live fluoroscopic injection of contrast. Once these tests were performed and negative for signs of intra-arterial needle placement, DSA imaging was utilized prior to medication administration for identification of vascular flow. A total number of 222 TFESI were performed, 41 injections at the cervical levels (18.47%), 113 at the lumbar levels (50.9%), and 68 at the sacral levels (30.36%). Flash was observed in 13 injections performed (5.85% of the total number of injections): one (0.45%) in the cervical, 2 (0.9%) in the lumbar, and 10 (4.5%) in the sacral levels. In 11 TFESI blood aspiration was obtained (4.95% of all injections): 3 (1.3%) in cervical, 4 (1.8%) in lumbar, and 4 (1.8%) in sacral injections. Live fluoroscopy during contrast injection detected 46 (20.72%) intravascular flow patterns: 7 (3.1%) cervical, 17 (7.6%) lumbar, and 22 (9.9%) sacral. DSA identified an additional 5 intravascular injections after all previous steps had resulted in negative vascular penetration signs, which accounted for 2.25% of all injections. This is a prospective, single-center study with a relatively small number of patients and no control group. DSA detected additional 5.26% intravascular needle placements following traditional methods. Our findings also support other studies that conclude TFESI are generally a safe procedure. We recommend that special attention should be paid to the sacral injections as vascular penetration was statistically higher than at other levels.

Spacelab 1 hematology experiment (INS103): Influence of space flight on erythrokinetics in man

NASA Technical Reports Server (NTRS)

Leach, C. S.; Chen, J. P.; Crosby, W.; Dunn, C. D. R.; Johnson, P. C.; Lange, R. D.; Larkin, E.; Tavassoli, M.

1985-01-01

An experiment conducted on the 10-day Spacelab 1 mission aboard the ninth Space Shuttle flight in November to December 1983 was designed to measure factors involved in the control of erythrocyte turnover that might be altered during weightlessness. Blood samples were collected before, during, and after the flight. Immediately after landing, red cell mass showed a mean decrease of 9.3 percent in the four astronauts. Neither hyperoxia nor an increase in blood phosphate was a cause of the decrease. Red cell survival time and iron incorporation postflight were not significantly different from their preflight levels. Serum haptoglobin did not decrease, indicating that intravascular hemolysis was not a major cause of red cell mass change. An increase in serum ferritin after the second day of flight may have been caused by red cell breakdown early in flight. Erythropoietin levels decreased during and after flight, but preflight levels were high and the decrease was not significant. The space flight-induced decrease in red cell mass may result from a failure of erythropoiesis to replace cells destroyed by the spleen soon after weightlessness is attained.

Disseminated intravascular coagulation (DIC)

MedlinePlus

... and vitamin K deficiency. In: Goldman L, Schafer AI, eds. Goldman-Cecil Medicine . 25th ed. Philadelphia, PA: Elsevier Saunders; 2016:chap 175. Review Date 10/21/2017 Updated by: Todd Gersten, MD, Hematology/Oncology, Florida Cancer Specialists & Research Institute, Wellington, FL. Review provided by ...

Localized gene delivery using antibody tethered adenovirus from polyurethane heart valve cusps and intra-aortic implants.

PubMed

Stachelek, S J; Song, C; Alferiev, I; Defelice, S; Cui, X; Connolly, J M; Bianco, R W; Levy, R J

2004-01-01

The present study investigated a novel approach for gene therapy of heart valve disease and vascular disorders. We formulated and characterized implantable polyurethane films that could also function as gene delivery systems through the surface attachment of replication defective adenoviruses using an anti-adenovirus antibody tethering mechanism. Our hypothesis was that we could achieve site-specific gene delivery to cells interacting with these polyurethane implants, and thereby demonstrate the potential for intravascular devices that could also function as gene delivery platforms for therapeutic vectors. Previous research by our group has demonstrated that polyurethane elastomers can be derivatized post-polymerization through a series of chemical reactions activating the hard segment amide groups with alkyl bromine residues, which can enable a wide variety of subsequent chemical modifications. Furthermore, prior research by our group investigating gene delivery intravascular stents has shown that collagen-coated balloon expandable stents can be configured with anti-adenovirus antibodies via thiol-based chemistry, and can then tether adenoviral vectors at doses that lead to high levels of localized arterial neointima expression, but with virtually no distal spread of vector. Thus, we sought to create two-device configurations for our investigations building on this previous research. (1) Polyurethane films coated with Type I collagen were thiol activated to permit covalent attachment of anti-adenovirus antibodies to enable gene delivery via vector tethering. (2) We also formulated polyurethane films with direct covalent attachment of anti-adenovirus antibodies to polyurethane hard segments derivatized with alkyl-thiol groups, thereby also enabling tethering of replication-defective adenoviruses. Both formulations demonstrated highly localized and efficient transduction in cell culture studies with rat arterial smooth muscle cells. In vivo experiments with collagen-coated polyurethane films investigated an abdominal aorta implant model in pigs using a button configuration that simulated the blood contacting environment of a vascular graft. One week explants of the collagen-coated polyurethane films demonstrated 14.3+/-2.5% of neointimal cells on the surface of the implant transduced with green fluorescent protein - adenovirus (AdGFP) vector loadings of 1 x 10(8) PFU. PCR studies demonstrated no detectable vector DNA in blood or distal organs. Similarly, polyurethane films with direct attachment of antivector antibodies to the surface were used in sheep pulmonary valve leaflet replacement studies, simulating the blood contacting environment of a prosthetic heart valve cusp. Polyurethane films with antibody tethered AdGFP vector (10(8) PFU) demonstrated 25.1+/-5.7% of attached cells transduced in these 1 week studies, with no detectable vector DNA in blood or distal organs. In vivo GFP expression was confirmed with immunohistochemistry. It is concluded that site-specific intravascular delivery of adenoviral vectors for gene therapy can be achieved with polyurethane implants utilizing the antivector antibody tethering mechanism.

21 CFR 880.5440 - Intravascular administration set.

Code of Federal Regulations, 2012 CFR

2012-04-01

...) Classification. Class II (special controls). The special control for pharmacy compounding systems within this classification is the FDA guidance document entitled “Class II Special Controls Guidance Document: Pharmacy Compounding Systems; Final Guidance for Industry and FDA Reviewers.” Pharmacy compounding systems classified...

21 CFR 880.5440 - Intravascular administration set.

Code of Federal Regulations, 2011 CFR

2011-04-01

...) Classification. Class II (special controls). The special control for pharmacy compounding systems within this classification is the FDA guidance document entitled “Class II Special Controls Guidance Document: Pharmacy Compounding Systems; Final Guidance for Industry and FDA Reviewers.” Pharmacy compounding systems classified...

21 CFR 880.5440 - Intravascular administration set.

Code of Federal Regulations, 2013 CFR

2013-04-01

...) Classification. Class II (special controls). The special control for pharmacy compounding systems within this classification is the FDA guidance document entitled “Class II Special Controls Guidance Document: Pharmacy Compounding Systems; Final Guidance for Industry and FDA Reviewers.” Pharmacy compounding systems classified...

21 CFR 880.5440 - Intravascular administration set.

Code of Federal Regulations, 2014 CFR

2014-04-01

...) Classification. Class II (special controls). The special control for pharmacy compounding systems within this classification is the FDA guidance document entitled “Class II Special Controls Guidance Document: Pharmacy Compounding Systems; Final Guidance for Industry and FDA Reviewers.” Pharmacy compounding systems classified...

Antithrombotic and thrombolytic effects of a new proteolytic preparation Trombovazim (Russia).

PubMed

Plotnikov, M B; Dygai, A M; Aliev, O I; Chernyshova, G A; Smol'yakova, V I; Vasil'ev, A S; Markov, V A; Vyshlov, E V; Vereschagin, E I; Kinsht, D N; Madonov, P G

2009-04-01

We studied the antithrombotic and thrombolytic effects of Trombovazim, a highly-purified proteolytic enzyme preparation obtained by immobilization of bacterial proteinases (Bacillus) on polyethylene oxide with a molecular weight of 1.5 kDa. Blood absorption of the preparation was evaluated after intragastric administration. In vitro experiments showed that Trombovazim produces anticoagulant and thrombolytic effects, which manifested in inhibition of fibrin clot formation and acceleration of its lysis. Drug concentration in the blood was elevated from the 4th to the 7th hour after intragastric administration of Trombovazim in a dose of 2250 U/kg, being maximum by the 5th hour (0.044+/-0.011 U/ml). Course treatment with Trombovazim (1000 U intragastrically, twice daily for 3 days) had a thrombolytic effect on rats with experimental intravascular thrombosis. This effect was manifested in a decrease in thrombus weight and increase in the percent of rats with recanalization of the occluded carotid artery.

The effect of cigarette smoke extract on thrombomodulin-thrombin binding: an atomic force microscopy study.

PubMed

Wei, Yujie; Zhang, Xuejie; Xu, Li; Yi, Shaoqiong; Li, Yi; Fang, Xiaohong; Liu, Huiliang

2012-10-01

Cigarette smoking is a well-known risk factor for cardiovascular disease. Smoking can cause vascular endothelial dysfunction and consequently trigger haemostatic activation and thrombosis. However, the mechanism of how smoking promotes thrombosis is not fully understood. Thrombosis is associated with the imbalance of the coagulant system due to endothelial dysfunction. As a vital anticoagulation cofactor, thrombomodulin (TM) located on the endothelial cell surface is able to regulate intravascular coagulation by binding to thrombin, and the binding results in thrombosis inhibition. This work focused on the effects of cigarette smoke extract (CSE) on TM-thrombin binding by atomic force microscopy (AFM) based single-molecule force spectroscopy. The results from both in vitro and live-cell experiments indicated that CSE could notably reduce the binding probability of TM and thrombin. This study provided a new approach and new evidence for studying the mechanism of thrombosis triggered by cigarette smoking.

Laser ablation of human atherosclerotic plaque without adjacent tissue injury

NASA Technical Reports Server (NTRS)

Grundfest, W. S.; Litvack, F.; Forrester, J. S.; Goldenberg, T.; Swan, H. J. C.

1985-01-01

Seventy samples of human cadaver atherosclerotic aorta were irradiated in vitro using a 308 nm xenon chloride excimer laser. Energy per pulse, pulse duration and frequency were varied. For comparison, 60 segments were also irradiated with an argon ion and an Nd:YAG laser operated in the continuous mode. Tissue was fixed in formalin, sectioned and examined microscopically. The Nd:YAG and argon ion-irradiated tissue exhibited a central crater with irregular edges and concentric zones of thermal and blast injury. In contrast, the excimer laser-irradiated tissue had narrow deep incisions with minimal or no thermal injury. These preliminary experiments indicate that the excimer laser vaporizes tissue in a manner different from that of the continuous wave Nd:YAG or argon ion laser. The sharp incision margins and minimal damage to adjacent normal tissue suggest that the excimer laser is more desirable for general surgical and intravascular uses than are the conventionally used medical lasers.

An implantable blood pressure and flow transmitter.

NASA Technical Reports Server (NTRS)

Rader, R. D.; Meehan, J. P.; Henriksen, J. K. C.

1973-01-01

A miniature totally implantable FM/FM telemetry system has been developed to simultaneously measure blood pressure and blood flow, thus providing an appreciation of the hemodynamics of the circulation to the entire body or to a particular organ. Developed for work with animal subjects, the telemetry system's transmission time is controlled by an RF signal that permits an operating life of several months. Pressure is detected by a miniature intravascular transducer and flow is detected by an extravascular interferometric ultrasonic technique. Both pressure and flow are calibrated prior to implanting. The pressure calibration can be checked after the implanting by cannulation; flow calibration can be verified only at the end of the experiment by determining the voltage output from the implanted sensing system as a function of several measured flow rates. The utility of this device has been established by its use in investigating canine renal circulation during exercise, emotional encounters, administration of drugs, and application of accelerative forces.

Enzymatic lipid oxidation by eosinophils propagates coagulation, hemostasis, and thrombotic disease

PubMed Central

Uderhardt, Stefan; Ackermann, Jochen A.; Fillep, Tobias; Hammond, Victoria J.; Willeit, Johann; Stark, Konstantin; Rossaint, Jan; Schubert, Irene; Mielenz, Dirk; Dietel, Barbara; Raaz-Schrauder, Dorette; Ay, Cihan; Thaler, Johannes; Heim, Christian; Collins, Peter W.; Schabbauer, Gernot; Mackman, Nigel; Voehringer, David; Nadler, Jerry L.; Lee, James J.; Massberg, Steffen; Rauh, Manfred; O’Donnell, Valerie B.

2017-01-01

Blood coagulation is essential for physiological hemostasis but simultaneously contributes to thrombotic disease. However, molecular and cellular events controlling initiation and propagation of coagulation are still incompletely understood. In this study, we demonstrate an unexpected role of eosinophils during plasmatic coagulation, hemostasis, and thrombosis. Using a large-scale epidemiological approach, we identified eosinophil cationic protein as an independent and predictive risk factor for thrombotic events in humans. Concurrent experiments showed that eosinophils contributed to intravascular thrombosis by exhibiting a strong endogenous thrombin-generation capacity that relied on the enzymatic generation and active provision of a procoagulant phospholipid surface enriched in 12/15-lipoxygenase–derived hydroxyeicosatetraenoic acid–phosphatidylethanolamines. Our findings reveal a previously unrecognized role of eosinophils and enzymatic lipid oxidation as regulatory elements that facilitate both hemostasis and thrombosis in response to vascular injury, thus identifying promising new targets for the treatment of thrombotic disease. PMID:28566277

Monte Carlo Simulations of Arterial Imaging with Optical Coherence Tomography

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

Amendt, P.; Estabrook, K.; Everett, M.

2000-02-01

The laser-tissue interaction code LATIS [London et al., Appl. Optics 36, 9068 ( 1998)] is used to analyze photon scattering histories representative of optical coherence tomography (OCT) experiment performed at Lawrence Livermore National Laboratory. Monte Carlo photonics with Henyey-Greenstein anisotropic scattering is implemented and used to simulate signal discrimination of intravascular structure. An analytic model is developed and used to obtain a scaling law relation for optimization of the OCT signal and to validate Monte Carlo photonics. The appropriateness of the Henyey-Greenstein phase function is studied by direct comparison with more detailed Mie scattering theory using an ensemble of sphericalmore » dielectric scatterers. Modest differences are found between the two prescriptions for describing photon angular scattering in tissue. In particular, the Mie scattering phase functions provide less overall reflectance signal but more signal contrast compared to the Henyey-Greenstein formulation.« less

Nosocomial infections in HIV-positive patients: an overview.

PubMed

Petrosillo, N; Pagani, L; Ippolito, G

2003-12-01

Nosocomial infections (NIs) constitute a significant public health problem and contribute to prolonged hospitalization, additional healthcare costs and excess morbidity and mortality. NIs appear to be more common in patients with acquired immunodeficiency syndrome (AIDS) as a result of some degree of immunosuppression, prior antiobiotics treatment and greater exposure to invasive devices such as indwelling intravenous catheters. The objective of this article is to give an insight into the main NIs occurring in HIV-infected patients. Literature pertaining to NIs in HIV-infected patients was reviewed. According to the leading studies in the literature, the incidence of NI ranges from 7.9 to 15 per 100 admissions. Bloodstream infections are the most frequent infections, mainly due to intravascular catheters, followed by urinary and respiratory tract infections. Colonization seems to have an important role in the development of NIs among this immunocompromised population. CLinicians need to be aware of the risk of NIs in HIV-infected patients, and must always take these infections into account in their overall management.

Erythrocyte creatine as a marker of intravascular hemolysis due to left ventricular outflow tract obstruction in hypertrophic cardiomyopathy.

PubMed

Kubo, Toru; Okumiya, Toshika; Baba, Yuichi; Hirota, Takayoshi; Tanioka, Katsutoshi; Yamasaki, Naohito; Sugiura, Tetsuro; Doi, Yoshinori L; Kitaoka, Hiroaki

2016-03-01

Erythrocyte creatine, a marker of erythrocyte age that increases with shortening of erythrocyte survival, has been reported to be a quantitative and reliable marker for intravascular hemolysis. We hypothesized that hemolysis could also occur due to intraventricular obstruction in patients with hypertrophic cardiomyopathy (HCM). The purpose of this study was to examine the presence of subclinical hemolysis and the relation between intravascular hemolysis and intraventricular pressure gradient (IVPG). We measured erythrocyte creatine in 92 HCM patients. Twelve patients had left ventricular outflow tract obstruction (LVOTO), 4 had midventricular obstruction (MVO), and the remaining 76 were non-obstructive. Erythrocyte creatine levels ranged from 0.92 to 4.36μmol/g hemoglobin. Higher levels of erythrocyte creatine were associated with higher IVPG (r=0.437, p<0.001). If erythrocyte creatine levels are high (≥1.8μmol/g hemoglobin), subclinical hemolysis is considered to be present. Half of LVOTO patients and no MVO patients showed high erythrocyte creatine levels. Although non-obstructive patients did not show significant intraventricular obstruction at rest, some showed high erythrocyte creatine levels. When LVOT-PG was measured during the strain phase of the Valsalva maneuver in 20 non-obstructive patients, 7 of those 20 patients showed LVOTO. In the 20 patients, there was no relation between erythrocyte creatine levels and LVOT-PG before the Valsalva maneuver (r=0.125, p=0.600), whereas there was a significant correlation between erythrocyte creatine and LVOT-PG provoked by the Valsalva maneuver (r=0.695, p=0.001). There is biochemical evidence of subclinical hemolysis in patients with HCM, and this hemolysis seems to be associated with LVOTO provoked by daily physical activities. Copyright © 2015 Japanese College of Cardiology. Published by Elsevier Ltd. All rights reserved.

Histological analysis on adhesive molecules of renal intravascular large B cell lymphoma treated with CHOP chemotherapy and rituximab.

PubMed

Kusaba, T; Hatta, T; Tanda, S; Kameyama, H; Tamagaki, K; Okigaki, M; Inaba, T; Shimazaki, C; Sasaki, S

2006-03-01

A 48-year-old man was admitted to our hospital for investigation of mild renal dysfunction. A blood examination revealed mild elevation of creatinine level (1.77 mg/dl). Urinary examination revealed mild protein excretion (0.54 g/day) and microhematuria; renal biopsy revealed the focal proliferation of large mononuclear cells with mitosis in glomerular capillaries. According to immunohistochemical analysis, the intravascular lymphomatous cells stained positively with anti-leukocyte common antigen (LCA: CD45) and CD20, indicating a B lymphocyte lineage. In electron microscopy, the glomerular capillary was filled with lymphoma cells and epithelial foot process fusion was noted. Immunohistochemical analysis on adhesive molecules revealed a lack of CD11a expression on lymphoma cells, but positive CD54 expression on endothelial cells. Systemic 18F-fluorodeoxyglucose positron emission tomography (FDG-PET) revealed no abnormal uptake of isotopes. On the basis of these findings, we diagnosed intravascular diffuse large B cell lymphoma localized in the kidney. Despite treatment with rituximab and CHOP (prednisolone, doxorubicin, vincristine, cyclophosphamide) for 3 cycles at 1-month intervals, the renal dysfunction did not change. In histopathological analysis of the second biopsy, lymphoma cells disappeared, but focal segmental glomerulosclerosis and moderate interstitial fibrosis were noted. Electron microscopic findings revealed severe subendothelial edema with mesangial interposition, indicating severe endothelial damage. Epithelial foot process fusion was improved. These pathological analyses let us conclude that a lack of CD11a could be a candidate factor for prevention of the extravasation of lymphoma cells from blood vessels in our patient. We also presumed that the intraglomerular endothelial damage occurred due to chemotherapy-associated cell injury.

Direct sGC Activation Bypasses NO Scavenging Reactions of Intravascular Free Oxy-Hemoglobin and Limits Vasoconstriction

PubMed Central

Tabima, D. Marcela; Specht, Patricia A.C.; Tejero, Jesús; Champion, Hunter C.; Kim-Shapiro, Daniel B.; Baust, Jeff; Mik, Egbert G.; Hildesheim, Mariana; Stasch, Johannes-Peter; Becker, Eva-Maria; Truebel, Hubert

2013-01-01

Abstract Aims: Hemoglobin-based oxygen carriers (HBOC) provide a potential alternative to red blood cell (RBC) transfusion. Their clinical application has been limited by adverse effects, in large part thought to be mediated by the intravascular scavenging of the vasodilator nitric oxide (NO) by cell-free plasma oxy-hemoglobin. Free hemoglobin may also cause endothelial dysfunction and platelet activation in hemolytic diseases and after transfusion of aged stored RBCs. The new soluble guanylate cyclase (sGC) stimulator Bay 41-8543 and sGC activator Bay 60-2770 directly modulate sGC, independent of NO bioavailability, providing a potential therapeutic mechanism to bypass hemoglobin-mediated NO inactivation. Results: Infusions of human hemoglobin solutions and the HBOC Oxyglobin into rats produced a severe hypertensive response, even at low plasma heme concentrations approaching 10 μM. These reactions were only observed for ferrous oxy-hemoglobin and not analogs that do not rapidly scavenge NO. Infusions of L-NG-Nitroarginine methyl ester (L-NAME), a competitive NO synthase inhibitor, after hemoglobin infusion did not produce additive vasoconstriction, suggesting that vasoconstriction is related to scavenging of vascular NO. Open-chest hemodynamic studies confirmed that hypertension occurred secondary to direct effects on increasing vascular resistance, with limited negative cardiac inotropic effects. Intravascular hemoglobin reduced the vasodilatory potency of sodium nitroprusside (SNP) and sildenafil, but had no effect on vasodilatation by direct NO-independent activation of sGC by BAY 41-8543 and BAY 60-2770. Innovation and Conclusion: These data suggest that both sGC stimulators and sGC activators could be used to restore cyclic guanosine monophosphate-dependent vasodilation in conditions where cell-free plasma hemoglobin is sufficient to inhibit endogenous NO signaling. Antioxid. Redox Signal. 19, 2232–2243. PMID:23697678

Impact of Type of Needle on Incidence of Intravascular Injection During Diagnostic Lumbar Medial Branch Block.

PubMed

Joo, Young; Kim, Yong Chul; Lee, Sang Chul; Kim, Hye Young; Park, Keun Suk; Choi, Eun Joo; Moon, Jee Youn

2016-01-01

Intravascular (IV) injection of local anesthetics is a potential cause of false-negative results after lumbar medial branch nerve blockade (L-MBB) performed to diagnose facetogenic back pain. The aim of the present study was to identify the relationship between the needle type and the incidence of IV injection in patients undergoing L-MBB using fluoroscopy with digital subtraction imaging (DSI). In this prospective randomized study, we compared the incidence of IV uptake of contrast medium using the Quincke needle and Whitacre needle under real-time DSI during L-MBB. Clinical and demographic factors associated with the occurrence of IV uptake were also investigated. In total, 126 patients were randomized into the Quincke needle group (n = 62) and Whitacre needle group (n = 64). Intravascular uptake of contrast medium was observed in 66 (9.8%) of 671 L-MBB procedures under DSI. The incidence of IV uptake was 13.9% (47/338) using the Quincke needle and 5.7% (19/333) using the Whitacre needle. In the multivariate generalized estimating equations analysis, use of a Quincke needle was related to positive IV injection at a 1.898-fold higher rate than was use of a Whitacre needle (95% confidence interval, 1.025-3.516) and a positive aspiration test predicted IV injection at a 21.735-fold higher rate (95% confidence interval, 11.996-52.258). Lumbar medial branch nerve blockade using the Quincke needle was associated with a 1.9-fold higher rate of IV injection than was L-MBB using the Whitacre needle under DSI. Although further study is needed to confirm the clinical efficacy, Whitacre needles can be considered to reduce the risk of IV injection during L-MBB.

Acetylcysteine for prevention of contrast-induced nephropathy after intravascular angiography: A systematic review and meta-analysis

PubMed Central

Bagshaw, Sean M; Ghali, William A

2004-01-01

Background Contrast-induced nephropathy is an important cause of acute renal failure. We assess the efficacy of acetylcysteine for prevention of contrast-induced nephropathy among patients undergoing intravascular angiography. Methods We conducted a systematic review and meta-analysis of randomized controlled trials comparing prophylactic acetylcysteine plus hydration versus hydration alone in patients undergoing intravascular angiography. Studies were identified by searching MEDLINE, EMBASE, and CENTRAL databases. Our main outcome measures were the risk of contrast-induced nephropathy and the difference in serum creatinine between acetylcysteine and control groups at 48 h. Results Fourteen studies involving 1261 patients were identified and included for analysis, and findings were heterogeneous across studies. Acetylcysteine was associated with a significantly reduced incidence of contrast-induced nephropathy in five studies, and no difference in the other nine (with a trend toward a higher incidence in six of the latter studies). The pooled odds ratio for contrast-induced nephropathy with acetylcysteine relative to control was 0.54 (95% CI, 0.32–0.91, p = 0.02) and the pooled estimate of difference in 48-h serum creatinine for acetylcysteine relative to control was -7.2 μmol/L (95% CI -19.7 to 5.3, p = 0.26). These pooled values need to be interpreted cautiously because of the heterogeneity across studies, and due to evidence of publication bias. Meta-regression suggested that the heterogeneity might be partially explained by whether the angiography was performed electively or as emergency. Conclusion These findings indicate that published studies of acetylcysteine for prevention of contrast-induced nephropathy yield inconsistent results. The efficacy of acetylcysteine will remain uncertain unless a large well-designed multi-center trial is performed. PMID:15500690

Noninvasive in vivo plasma volume and hematocrit in humans: observing long-term baseline behavior to establish homeostasis for intravascular volume and composition

NASA Astrophysics Data System (ADS)

Dent, Paul; Deng, Bin; Goodisman, Jerry; Peterson, Charles M.; Narsipur, Sriram; Chaiken, J.

2016-04-01

A new device incorporating a new algorithm and measurement process allows simultaneous noninvasive in vivo monitoring of intravascular plasma volume and red blood cell volume. The purely optical technique involves probing fingertip skin with near infrared laser light and collecting the wavelength shifted light, that is, the inelastic emission (IE) which includes the unresolved Raman and fluorescence, and the un-shifted emission, that is, the elastic emission (EE) which includes both the Rayleigh and Mie scattered light. Our excitation and detection geometry is designed so that from these two simultaneous measurements we can calculate two parameters within the single scattering regime using radiation transfer theory, the intravascular plasma volume fraction and the red blood cell volume fraction. Previously calibrated against a gold standard FDA approved device, 2 hour monitoring sessions on three separate occasions over a three week span for a specific, motionless, and mostly sleeping individual produced 3 records containing a total of 5706 paired measurements of hematocrit and plasma volume. The average over the three runs, relative to the initial plasma volume taken as 100%, of the plasma volume±1σ was 97.56+/-0.55 or 0.56%.For the same three runs, the average relative hematocrit (Hct), referenced to an assumed initial value of 28.35 was 29.37+/-0.12 or stable to +/-0.4%.We observe local deterministic circulation effects apparently associated with the pressure applied by the finger probe as well as longer timescale behavior due to normal ebb and flow of internal fluids due to posture changes and tilt table induced gravity gradients.

A comparison of Espocan and Tuohy needles for the combined spinal-epidural technique for labor analgesia.

PubMed

Browne, Ingrid M; Birnbach, David J; Stein, Deborah J; O'Gorman, David A; Kuroda, Maxine

2005-08-01

When using the needle-through-needle combined spinal-epidural (CSE) technique for labor analgesia, failure to obtain cerebrospinal fluid (CSF), paresthesias, and intrathecal or intravascular migration of the catheter are of concern. Epidural needles with spinal needle apertures, such as the back-hole Espocan (ES) needles, are available and may reduce these risks. We describe the efficacy and adverse events associated with a modified epidural needle (ES) versus a conventional Tuohy needle for CSE. One-hundred parturients requesting labor analgesia (CSE) were randomized into 2 groups: 50-ES 18-gauge modified epidural needle with 27-gauge Pencan atraumatic spinal needle, 50-conventional 18-gauge Tuohy needle with 27-gauge Gertie Marx atraumatic spinal needle. Information on intrathecal or intravascular catheter placement, paresthesia on introduction of spinal needle, failure to obtain CSF through the spinal needle after placement of epidural needle, unintentional dural puncture, and epidural catheter function was obtained. No intrathecal catheter placement occurred in either group. Rates of intravascular catheter placement and unintentional dural puncture were similar between the groups. Significant differences were noted regarding spinal needle-induced paresthesia (14% ES versus 42% Tuohy needles, P = 0.009) and failure to obtain CSF on first attempt (8% ES versus 28% Tuohy needles, P < 0.02). Use of ES needles for CSE significantly reduces paresthesia associated with the insertion of the spinal needle and is associated with more frequent successful spinal needle placement on the first attempt. The use of modified epidural needles with a back hole for combined spinal-epidural technique significantly reduces paresthesia associated with the insertion of the spinal needle and is associated with more frequent successful spinal needle placement on the first attempt.

Intravascular application of electrocautery in a rabbit model of abdominal aortic endarterectomy

PubMed Central

Wang, Chuan; Xin, Yi; Li, Na; Li, Diankun; Li, Jingxing; Gu, Chengxiong

2017-01-01

Effective therapies for preventing perioperative complications such as thrombosis and inflammation after coronary endarterectomy (CE) are lacking. Electrocoagulation electrotomes have been routinely used in surgery for their cutting, clotting, and hemostatic properties. As strong flattening tools, their electrocautery function may prevent mechanical intimal-adventitial injury to arterial circulation and attenuate stenosis. The present study investigated the effects of intravascular application of electrocautery on ameliorating inflammation and thrombosis in a rabbit model of abdominal aortic endarterectomy. New Zealand rabbits were randomly divided into the sham, control (endarterectomy), and study (endarterectomy + electrocautery) groups with 10 in each group. Abdominal aortas were partially blocked and intima was removed. Electrocautery was performed with an electrocoagulation electrotome through the entire blocked vessel lumen. Vascular ultrasound parameters, molecular biological and histological characteristics of the abdominal aorta including vascular diameter, blood flow velocity, serum interleukin-6 (IL-6) and tumor necrosis factor-α (TNF-α) levels, and apoptosis rate of vascular endothelial cells (ECs) were evaluated postoperatively by vascular Doppler ultrasound, ELISA, real-time RT-PCR, flow cytometry, and immunofluorescence at various time points. Compared with the endarterectomy + electrocautery group, the isolated endarterectomy group had significantly increased levels and gene expression of TNF-α and IL-6 (P<0.05), and rates of apoptosis of vascular ECs (P<0.05), with gradual vascular stenosis and decreased blood flow velocity. In conclusion, intravascular application of electrocautery has favorable short-term effects on the abdominal aorta and can reduce inflammation in a rabbit model of abdominal aorta endarterectomy. Long-term anti-inflammatory and anti-thrombotic effects on arterial remodeling and the clinical value of electrocautery in CE remain to be determined. PMID:28672932

Intravascular application of electrocautery in a rabbit model of abdominal aortic endarterectomy.

PubMed

Wang, Chuan; Xin, Yi; Li, Na; Li, Diankun; Li, Jingxing; Gu, Chengxiong

2017-07-01

Effective therapies for preventing perioperative complications such as thrombosis and inflammation after coronary endarterectomy (CE) are lacking. Electrocoagulation electrotomes have been routinely used in surgery for their cutting, clotting, and hemostatic properties. As strong flattening tools, their electrocautery function may prevent mechanical intimal-adventitial injury to arterial circulation and attenuate stenosis. The present study investigated the effects of intravascular application of electrocautery on ameliorating inflammation and thrombosis in a rabbit model of abdominal aortic endarterectomy. New Zealand rabbits were randomly divided into the sham, control (endarterectomy), and study (endarterectomy + electrocautery) groups with 10 in each group. Abdominal aortas were partially blocked and intima was removed. Electrocautery was performed with an electrocoagulation electrotome through the entire blocked vessel lumen. Vascular ultrasound parameters, molecular biological and histological characteristics of the abdominal aorta including vascular diameter, blood flow velocity, serum interleukin-6 (IL-6) and tumor necrosis factor-α (TNF-α) levels, and apoptosis rate of vascular endothelial cells (ECs) were evaluated postoperatively by vascular Doppler ultrasound, ELISA, real-time RT-PCR, flow cytometry, and immunofluorescence at various time points. Compared with the endarterectomy + electrocautery group, the isolated endarterectomy group had significantly increased levels and gene expression of TNF-α and IL-6 (P<0.05), and rates of apoptosis of vascular ECs (P<0.05), with gradual vascular stenosis and decreased blood flow velocity. In conclusion, intravascular application of electrocautery has favorable short-term effects on the abdominal aorta and can reduce inflammation in a rabbit model of abdominal aorta endarterectomy. Long-term anti-inflammatory and anti-thrombotic effects on arterial remodeling and the clinical value of electrocautery in CE remain to be determined.

Atrial Fibrillation Pacing Decreases Intravascular Shear Stress in a New Zealand White Rabbit Model: Implications in Endothelial Function

PubMed Central

Jen, Nelson; Yu, Fei; Lee, Juhyun; Wasmund, Steve; Dai, Xiaohu; Chen, Christina; Chawareeyawong, Pai; Yang, Yongmo; Li, Rongsong; Hamdan, Mohamed H.; Hsiai, Tzung

2012-01-01

Atrial fibrillation (AF) is characterized by multiple rapid and irregular atrial depolarization leading to rapid ventricular responses exceeding 100 beats per minute (bpm). We hypothesized that rapid and irregular pacing reduced intravascular shear stress (ISS) with implication to modulating endothelial responses. To simulate AF, we paced the left atrial appendage of New Zealand White (NZW) rabbits (n=4) at rapid and irregular intervals. Surface electrical cardiograms (ECG) were recorded for atrial and ventricular rhythm, and intravascular convective heat transfer was measured by micro thermal sensors, from which ISS was inferred. Rapid and irregular pacing decreased arterial systolic and diastolic pressures (baseline: 99/75 mmHg; rapid regular pacing: 92/73; rapid irregular pacing: 90/68; P < 0.001, n=4), temporal gradients (∂τ/∂t from 1275 ± 80 to 1056 ± 180 dyne/cm2·s), and reduced ISS (from baseline at 32.0 ± 2.4 to 22.7 ± 3.5 dyne/cm2). Computational fluid dynamics (CFD) code demonstrated that experimentally inferred ISS provided a close approximation to the computed wall shear stress (WSS) at a given catheter to vessel diameter ratio, shear stress range, and catheter position. In an in vitro flow system in which time-averaged shear stress was maintained at τavg=23 ±4 dyn·cm−2·s−1, we further demonstrated that rapid pulse rates at 150 bpm down-regulated endothelial nitric oxide (NO), promoted superoxide (O2·−) production, and increased monocyte binding to endothelial cells. These findings suggest that rapid pacing reduces ISS and ∂τ/∂t, and rapid pulse rates modulate endothelial responses. PMID:22983703

Minimally Invasive Monitoring of Chronic Central Venous Catheter Patency in Mice Using Digital Subtraction Angiography (DSA)

PubMed Central

Figueiredo, Giovanna; Fiebig, Teresa; Kirschner, Stefanie; Nikoubashman, Omid; Kabelitz, Lisa; Othman, Ahmed; Nonn, Andrea; Kramer, Martin; Brockmann, Marc A.

2015-01-01

Background Repetitive administration of medication or contrast agents is frequently performed in mice. The introduction of vascular access mini-ports (VAMP) for mice allows long-term vascular catheterization, hereby eliminating the need for repeated vessel puncture. With catheter occlusion being the most commonly reported complication of chronic jugular vein catheterization, we tested whether digital subtraction angiography (DSA) can be utilized to evaluate VAMP patency in mice. Methods Twenty-three mice underwent catheterization of the jugular vein and subcutaneous implantation of a VAMP. The VAMP was flushed every second day with 50 μL of heparinized saline solution (25 IU/ml). DSA was performed during injection of 100 μL of an iodine based contrast agent using an industrial X-ray inspection system intraoperatively, as well as 7±2 and 14±2 days post implantation. Results DSA allowed localization of catheter tip position, to rule out dislocation, kinking or occlusion of a microcatheter, and to evaluate parent vessel patency. In addition, we observed different ante- and retrograde collateral flow patterns in case of jugular vein occlusion. More exactly, 30% of animals showed parent vessel occlusion after 7±2 days in our setting. At this time point, nevertheless, all VAMPs verified intravascular contrast administration. After 14±2 days, intravascular contrast injection was verified in 70% of the implanted VAMPs, whereas at this point of time 5 animals had died or were sacrificed and in 2 mice parent vessel occlusion hampered intravascular contrast injection. Notably, no occlusion of the catheter itself was observed. Conclusion From our observations we conclude DSA to be a fast and valuable minimally invasive tool for investigation of catheter and parent vessel patency and for anatomical studies of collateral blood flow in animals as small as mice. PMID:26098622

Double Knockout of the Na+-Driven Cl−/HCO3− Exchanger and Na+/Cl− Cotransporter Induces Hypokalemia and Volume Depletion

PubMed Central

Sinning, Anne; Radionov, Nikita; Trepiccione, Francesco; López-Cayuqueo, Karen I.; Jayat, Maximilien; Baron, Stéphanie; Cornière, Nicolas; Alexander, R. Todd; Hadchouel, Juliette; Eladari, Dominique; Hübner, Christian A.

2017-01-01

We recently described a novel thiazide–sensitive electroneutral NaCl transport mechanism resulting from the parallel operation of the Cl−/HCO3− exchanger pendrin and the Na+–driven Cl−/2HCO3− exchanger (NDCBE) in β-intercalated cells of the collecting duct. Although a role for pendrin in maintaining Na+ balance, intravascular volume, and BP is well supported, there is no in vivo evidence for the role of NDCBE in maintaining Na+ balance. Here, we show that deletion of NDCBE in mice caused only subtle perturbations of Na+ homeostasis and provide evidence that the Na+/Cl− cotransporter (NCC) compensated for the inactivation of NDCBE. To unmask the role of NDCBE, we generated Ndcbe/Ncc double–knockout (dKO) mice. On a normal salt diet, dKO and single-knockout mice exhibited similar activation of the renin-angiotensin-aldosterone system, whereas only dKO mice displayed a lower blood K+ concentration. Furthermore, dKO mice displayed upregulation of the epithelial sodium channel (ENaC) and the Ca2+–activated K+ channel BKCa. During NaCl depletion, only dKO mice developed marked intravascular volume contraction, despite dramatically increased renin activity. Notably, the increase in aldosterone levels expected on NaCl depletion was attenuated in dKO mice, and single-knockout and dKO mice had similar blood K+ concentrations under this condition. In conclusion, NDCBE is necessary for maintaining sodium balance and intravascular volume during salt depletion or NCC inactivation in mice. Furthermore, NDCBE has an important role in the prevention of hypokalemia. Because NCC and NDCBE are both thiazide targets, the combined inhibition of NCC and the NDCBE/pendrin system may explain thiazide-induced hypokalemia in some patients. PMID:27151921

Double Knockout of the Na+-Driven Cl-/HCO3- Exchanger and Na+/Cl- Cotransporter Induces Hypokalemia and Volume Depletion.

PubMed

Sinning, Anne; Radionov, Nikita; Trepiccione, Francesco; López-Cayuqueo, Karen I; Jayat, Maximilien; Baron, Stéphanie; Cornière, Nicolas; Alexander, R Todd; Hadchouel, Juliette; Eladari, Dominique; Hübner, Christian A; Chambrey, Régine

2017-01-01

We recently described a novel thiazide-sensitive electroneutral NaCl transport mechanism resulting from the parallel operation of the Cl - /HCO 3 - exchanger pendrin and the Na + -driven Cl - /2HCO 3 - exchanger (NDCBE) in β-intercalated cells of the collecting duct. Although a role for pendrin in maintaining Na + balance, intravascular volume, and BP is well supported, there is no in vivo evidence for the role of NDCBE in maintaining Na + balance. Here, we show that deletion of NDCBE in mice caused only subtle perturbations of Na + homeostasis and provide evidence that the Na + /Cl - cotransporter (NCC) compensated for the inactivation of NDCBE. To unmask the role of NDCBE, we generated Ndcbe/Ncc double-knockout (dKO) mice. On a normal salt diet, dKO and single-knockout mice exhibited similar activation of the renin-angiotensin-aldosterone system, whereas only dKO mice displayed a lower blood K + concentration. Furthermore, dKO mice displayed upregulation of the epithelial sodium channel (ENaC) and the Ca 2+ -activated K + channel BKCa. During NaCl depletion, only dKO mice developed marked intravascular volume contraction, despite dramatically increased renin activity. Notably, the increase in aldosterone levels expected on NaCl depletion was attenuated in dKO mice, and single-knockout and dKO mice had similar blood K + concentrations under this condition. In conclusion, NDCBE is necessary for maintaining sodium balance and intravascular volume during salt depletion or NCC inactivation in mice. Furthermore, NDCBE has an important role in the prevention of hypokalemia. Because NCC and NDCBE are both thiazide targets, the combined inhibition of NCC and the NDCBE/pendrin system may explain thiazide-induced hypokalemia in some patients. Copyright © 2016 by the American Society of Nephrology.

Multimodality Intra-Arterial Imaging Assessment of the Vascular Trauma Induced by Balloon-Based and Nonballoon-Based Renal Denervation Systems.

PubMed

Karanasos, Antonios; Van Mieghem, Nicolas; Bergmann, Martin W; Hartman, Eline; Ligthart, Jurgen; van der Heide, Elco; Heeger, Christian-H; Ouhlous, Mohamed; Zijlstra, Felix; Regar, Evelyn; Daemen, Joost

2015-07-01

Renal denervation is a new treatment considered for several possible indications. As new systems are introduced, the incidence of acute renal artery wall injury with relation to the denervation method is unknown. We investigated the acute repercussion of renal denervation on the renal arteries of patients treated with balloon-based and nonballoon-based denervation systems by quantitative angiography, intravascular ultrasound, and optical coherence tomography (OCT). Twenty-five patients (50 renal arteries) underwent bilateral renal denervation with 5 different systems, 3 of which balloon-based (Paradise [n=5], Oneshot [n=6], and Vessix V2 [n=5)]) and 2 nonballoon-based (Symplicity [n=6] and EnligHTN [n=3]). Analysis included quantitative angiography and morphometric intravascular ultrasound measurements pre and post procedure and assessment of vascular trauma (dissection, edema, or thrombus) by OCT after denervation. A significant reduction in lumen size by quantitative angiography and intravascular ultrasound was observed in nonballoon denervation but not in balloon denervation. By postdenervation OCT, dissection was seen in 14 arteries (32.6%). The percentage of frames with dissection was higher in balloon-based denervation catheters. Thrombus and edema were detected in 35 (81.4%) and 32 (74.4%) arteries, respectively. In arteries treated with balloon-based denervation that had dissection by OCT, the balloon/artery ratio was higher (1.24 [1.17-1.32] versus 1.10 [1.04-1.18]; P<0.01). A varying extent of vascular injury was observed after renal denervation in all systems; however, different patterns were identified in balloon-based and in nonballoon-based denervation systems. In balloon denervation, the presence of dissections by OCT was associated with a higher balloon/artery ratio. © 2015 American Heart Association, Inc.

Different Impact of Essential Hypertension on Structural and Functional Age-Related Vascular Changes.

PubMed

Bruno, Rosa Maria; Duranti, Emiliano; Ippolito, Chiara; Segnani, Cristina; Bernardini, Nunzia; Di Candio, Giulio; Chiarugi, Massimo; Taddei, Stefano; Virdis, Agostino

2017-01-01

We evaluated whether vascular remodeling is present in physiological aging and whether hypertension accelerates the aging process for vascular function and structure. Small arteries from 42 essential hypertensive patients (HT) and 41 normotensive individuals (NT) were dissected after subcutaneous biopsy. Endothelium-dependent vasodilation (pressurized myograph) was assessed by acetylcholine, repeated under the nitric oxide synthase inhibitor N-nitro-l-arginine methylester or the antioxidant tempol. Structure was evaluated by media-lumen ratio (M/L). Intravascular oxidative generation and collagen deposition were assessed. Inhibition by N-nitro-l-arginine methylester on ACh was inversely related to age in both groups (P<0.0001) and blunted in HT versus NT for each age range. In NT, tempol enhanced endothelial function in the oldest subgroup; in HT, the potentiating effect started earlier. HT showed an increased M/L (P<0.001) versus control. In both groups, M/L was directly related to age (P<0.0001). M/L was greater in HT, starting from 31 to 45 years range. A significant age-hypertension interaction occurred (P=0.0009). In NT, intravascular superoxide emerged in the oldest subgroup, whereas it appeared earlier among HT. Among NT, aged group displayed an increment of collagen fibers versus young group. In HT, collagen deposition was already evident in youngest, with a further enhancement in the aged group. In small arteries, ageing shows a eutrophic vascular remodeling and a reduced nitric oxide availability. Oxidative stress and fibrosis emerge in advanced age. In HT, nitric oxide availability is early reduced, but the progression rate with age is similar. Structural alterations include wide collagen deposition and intravascular reactive oxygen species, and the progression rate with age is steeper. © 2016 American Heart Association, Inc.

LumenRECON Guidewire: Pilot Study of a Novel, Nonimaging Technology for Accurate Vessel Sizing and Delivery of Therapy in Femoropopliteal Disease.

PubMed

Nair, Pradeep K; Carr, Jeffrey G; Bigelow, Brian; Bhatt, Deepak L; Berwick, Zachary C; Adams, George

2018-01-01

Proper vessel sizing during endovascular interventions is crucial to avoid adverse procedural and clinical outcomes. LumenRECON (LR) is a novel, nonimaging, 0.035-inch wire-based technology that uses the physics-based principle of Ohm's law to provide a simple, real-time luminal size while also providing a platform for therapy delivery. This study evaluated the accuracy, reliability, and safety of the LR system in patients presenting for a femoropopliteal artery intervention. This multicenter, prospective pilot study of 24 patients presenting for peripheral intervention compared LR measurements of femoropopliteal artery size to angiographic visual estimation, duplex ultrasound, quantitative angiography, and intravascular ultrasound. The primary effectiveness and safety end point was comparison against core laboratory adjudicated intravascular ultrasound values and major adverse events, respectively. Additional preclinical studies were also performed in vitro and in vivo in swine to determine the accuracy of the LR guidewire system. No intra- or postprocedure device-related adverse events occurred. A balloon or stent was successfully delivered in 12 patients (50%) over the LR wire. Differences in repeatability between successive LR measurements was 2.5±0.40% ( R 2 =0.96) with no significant bias. Differences in measurements of LR to other modalities were 0.5±1.7%, 5.0±1.8%, -1.5±2.0%, and 6.8±3.4% for intravascular ultrasound core laboratory, quantitative angiography, angiographic, and duplex ultrasound, respectively. This study demonstrates that through a physics-based principle, LR provides a real-time, safe, reproducible, and accurate vessel size of the femoropopliteal artery during intervention and can additionally serve as a conduit for therapy delivery over its wire-based platform. © 2018 American Heart Association, Inc.

Numerical Modeling of Interstitial Fluid Flow Coupled with Blood Flow through a Remodeled Solid Tumor Microvascular Network

PubMed Central

Soltani, M.; Chen, P.

2013-01-01

Modeling of interstitial fluid flow involves processes such as fluid diffusion, convective transport in extracellular matrix, and extravasation from blood vessels. To date, majority of microvascular flow modeling has been done at different levels and scales mostly on simple tumor shapes with their capillaries. However, with our proposed numerical model, more complex and realistic tumor shapes and capillary networks can be studied. Both blood flow through a capillary network, which is induced by a solid tumor, and fluid flow in tumor’s surrounding tissue are formulated. First, governing equations of angiogenesis are implemented to specify the different domains for the network and interstitium. Then, governing equations for flow modeling are introduced for different domains. The conservation laws for mass and momentum (including continuity equation, Darcy’s law for tissue, and simplified Navier–Stokes equation for blood flow through capillaries) are used for simulating interstitial and intravascular flows and Starling’s law is used for closing this system of equations and coupling the intravascular and extravascular flows. This is the first study of flow modeling in solid tumors to naturalistically couple intravascular and extravascular flow through a network. This network is generated by sprouting angiogenesis and consisting of one parent vessel connected to the network while taking into account the non-continuous behavior of blood, adaptability of capillary diameter to hemodynamics and metabolic stimuli, non-Newtonian blood flow, and phase separation of blood flow in capillary bifurcation. The incorporation of the outlined components beyond the previous models provides a more realistic prediction of interstitial fluid flow pattern in solid tumors and surrounding tissues. Results predict higher interstitial pressure, almost two times, for realistic model compared to the simplified model. PMID:23840579

3D registration of intravascular optical coherence tomography and cryo-image volumes for microscopic-resolution validation

NASA Astrophysics Data System (ADS)

Prabhu, David; Mehanna, Emile; Gargesha, Madhusudhana; Wen, Di; Brandt, Eric; van Ditzhuijzen, Nienke S.; Chamie, Daniel; Yamamoto, Hirosada; Fujino, Yusuke; Farmazilian, Ali; Patel, Jaymin; Costa, Marco; Bezerra, Hiram G.; Wilson, David L.

2016-03-01

High resolution, 100 frames/sec intravascular optical coherence tomography (IVOCT) can distinguish plaque types, but further validation is needed, especially for automated plaque characterization. We developed experimental and 3D registration methods, to provide validation of IVOCT pullback volumes using microscopic, brightfield and fluorescent cryoimage volumes, with optional, exactly registered cryo-histology. The innovation was a method to match an IVOCT pullback images, acquired in the catheter reference frame, to a true 3D cryo-image volume. Briefly, an 11-parameter, polynomial virtual catheter was initialized within the cryo-image volume, and perpendicular images were extracted, mimicking IVOCT image acquisition. Virtual catheter parameters were optimized to maximize cryo and IVOCT lumen overlap. Local minima were possible, but when we started within reasonable ranges, every one of 24 digital phantom cases converged to a good solution with a registration error of only +1.34+/-2.65μm (signed distance). Registration was applied to 10 ex-vivo cadaver coronary arteries (LADs), resulting in 10 registered cryo and IVOCT volumes yielding a total of 421 registered 2D-image pairs. Image overlays demonstrated high continuity between vascular and plaque features. Bland- Altman analysis comparing cryo and IVOCT lumen area, showed mean and standard deviation of differences as 0.01+/-0.43 mm2. DICE coefficients were 0.91+/-0.04. Finally, visual assessment on 20 representative cases with easily identifiable features suggested registration accuracy within one frame of IVOCT (+/-200μm), eliminating significant misinterpretations introduced by 1mm errors in the literature. The method will provide 3D data for training of IVOCT plaque algorithms and can be used for validation of other intravascular imaging modalities.

Severe Postpartum Hemorrhage from Uterine Atony: A Multicentric Study

PubMed Central

Montufar-Rueda, Carlos; Rodriguez, Laritza; Jarquin, José Douglas; Barboza, Alejandra; Bustillo, Maura Carolina; Marin, Flor; Ortiz, Guillermo; Estrada, Francisco

2013-01-01

Objective. Postpartum hemorrhage (PPH) is an important cause of maternal mortality (MM) around the world. Seventy percent of the PPH corresponds to uterine atony. The objective of our study was to evaluate multicenter PPH cases during a 10-month period, and evaluate severe postpartum hemorrhage management. Study Design. The study population is a cohort of vaginal delivery and cesarean section patients with severe postpartum hemorrhage secondary to uterine atony. The study was designed as a descriptive, prospective, longitudinal, and multicenter study, during 10 months in 13 teaching hospitals. Results. Total live births during the study period were 124,019 with 218 patients (0.17%) with severe postpartum hemorrhage (SPHH). Total maternal deaths were 8, for mortality rate of 3.6% and a MM rate of 6.45/100,000 live births (LB). Maternal deaths were associated with inadequate transfusion therapy. Conclusions. In all patients with severe hemorrhage and subsequent hypovolemic shock, the most important therapy is intravascular volume resuscitation, to reduce the possibility of target organ damage and death. Similarly, the current proposals of transfusion therapy in severe or massive hemorrhage point to early transfusion of blood products and use of fresh frozen plasma, in addition to packed red blood cells, to prevent maternal deaths. PMID:24363935

RF Ablation of Giant Hemangiomas Inducing Acute Renal Failure: A Report of Two Cases

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

Tilborg, Aukje A. J. M. van, E-mail: a.vantilborg@vumc.nl; Dresselaars, Helena F.; Scheffer, Hester J.

ObjectiveIn patients that require treatment for hepatic giant cavernous hemangiomas (GCH), radiofrequency ablation (RFA) has been suggested to represent a safe and effective alternative to invasive surgery. In a recent report of bipolar RFA, using two expandable needle electrodes, was uneventfully performed in patients with large GCH (>10 cm). The objective of this report is to present two cases in which bipolar RFA of symptomatic GCH was complicated by acute kidney injury.Materials and methodsIn 2015 we treated two patients for very large symptomatic GCH (15.7 and 25.0 cm) with bipolar RFA during open laparotomy.ResultsIn both patients the urine showed a red–brown discolorationmore » directly after the ablation. They became anuric and presented with progressive dyspnea, tachypnea, and tachycardia, requiring hemodialysis for a period of 1 month in one case. Lab results revealed hemepigment-induced acute kidney. Both patients fully recovered and both showed a complete relief of symptoms at 3 months following the procedure.ConclusionRFA for large GCHs can cause hemepigment-induced acute kidney injury due to massive intravascular hemolysis. The presented cases suggest that caution is warranted and advocate an upper limit regarding the volume of GCHs that can be safely ablated.« less

Artificial Red Cells with Polyhemoglobin Membranes.

DTIC Science & Technology

1981-09-01

4,4’-diaminobiphenyl-2,2’-disulfonic acid to improve the dispersability of his nylon cells, but their intravascular persistence was short. (24) Kondo...Group, decaglycerol decaoleate, HLB 2.0 * Cholesterol, Aldrich Chemical Co., HLB 2.0 " Alcolec PG, American Lecithin Co., purified soy phosphatides

in silico Vascular Modeling for Personalized Nanoparticle Delivery

DTIC Science & Technology

2012-02-01

stent implantation . Annals of Biomedical Engineering 2003;31(8): 972-80. 21. Decuzzi P, Pasqualini R, Arap W, Ferrari M. Intravascular Delivery of...transport and adhesion dynamics under controlled flow conditions (Supplementary Figure 1A). The flow chamber system comprises a PMMA flow deck, a

Validating Intravascular Imaging with Serial Optical Coherence Tomography and Confocal Fluorescence Microscopy.

PubMed

Tardif, Pier-Luc; Bertrand, Marie-Jeanne; Abran, Maxime; Castonguay, Alexandre; Lefebvre, Joël; Stähli, Barbara E; Merlet, Nolwenn; Mihalache-Avram, Teodora; Geoffroy, Pascale; Mecteau, Mélanie; Busseuil, David; Ni, Feng; Abulrob, Abedelnasser; Rhéaume, Éric; L'Allier, Philippe; Tardif, Jean-Claude; Lesage, Frédéric

2016-12-15

Atherosclerotic cardiovascular diseases are characterized by the formation of a plaque in the arterial wall. Intravascular ultrasound (IVUS) provides high-resolution images allowing delineation of atherosclerotic plaques. When combined with near infrared fluorescence (NIRF), the plaque can also be studied at a molecular level with a large variety of biomarkers. In this work, we present a system enabling automated volumetric histology imaging of excised aortas that can spatially correlate results with combined IVUS/NIRF imaging of lipid-rich atheroma in cholesterol-fed rabbits. Pullbacks in the rabbit aortas were performed with a dual modality IVUS/NIRF catheter developed by our group. Ex vivo three-dimensional (3D) histology was performed combining optical coherence tomography (OCT) and confocal fluorescence microscopy, providing high-resolution anatomical and molecular information, respectively, to validate in vivo findings. The microscope was combined with a serial slicer allowing for the imaging of the whole vessel automatically. Colocalization of in vivo and ex vivo results is demonstrated. Slices can then be recovered to be tested in conventional histology.

In vivo evaluation of a fluorine-acryl-stylene-urethane-silicone antithrombogenic coating material copolymer for intravascular stents.

PubMed

Matsuhashi, T; Miyachi, H; Ishibashi, T; Sakamoto, K; Yamadera, A

1996-07-01

We evaluated the effectiveness of a fluorine-acryl-styrene-urethane-silicone (FASUS) copolymer as an antithrombogenic coating material for intravascular stents in dogs. FASUS copolymer-coated stents were placed in the right iliac veins, and uncoated 304 stainless steel stents were placed in the left iliac veins. We examined platelet deposition, microthrombus formation, and neointimal hyperplasia 4 weeks after stent placement by measuring the activity of 111In-labeled platelets, by using scanning electron microscopy, and by measuring neointimal thickness. Platelet deposition was significantly decreased on coated than on uncoated stents (p < .05). A less pronounced increase in red blood cell deposition was observed at the sites of the coated than uncoated stents (p < .05). Neointimal thickness 4 weeks after stent placement also was significantly less at the sites of the coated stents (0.27 +/- 0.08 mm versus 0.48 +/- 0.23 mm, p < .05). FASUS copolymer coating over the vascular stent is effective for preventing thrombus formation and neointimal hyperplasia.

Albumin extravasation rates in tissues of anesthetized and unanesthetized rats

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

Renkin, E.M.; Joyner, W.L.; Gustafson-Sgro, M.

Bovine serum albumin (BSA) labeled with /sup 131/I was injected intravenously in chronically prepared, unanesthetized rats and into pentobarbital-anesthetized rats that had received 2 ml 5% BSA to help sustain plasma volume. Initial uptake rates (clearances) in skin, skeletal muscles, diaphragm, and heart (left ventricle) were measured over 1 h. BSA labeled with /sup 125/I was injected terminally to correct for intravascular /sup 131/I-BSA. Observed clearances were in the following order in both groups of animals: heart much greater than diaphragm approximately equal to skin greater than resting skeletal muscles. Differences between unanesthetized and anesthetized animals were small and inconsistentlymore » directed. Our results suggest that the lower albumin clearances reported in the literature for anesthetized rats are not the result of their immobility or any direct effect of anesthesia on albumin transport in these tissues. The lower transport rates appear to result indirectly from changes produced by anesthesia and/or surgery in controllable parameters such as plasma volume and intravascular protein mass.« less

Heartbeat OCT: in vivo intravascular megahertz-optical coherence tomography

PubMed Central

Wang, Tianshi; Pfeiffer, Tom; Regar, Evelyn; Wieser, Wolfgang; van Beusekom, Heleen; Lancee, Charles T.; Springeling, Geert; Krabbendam, Ilona; van der Steen, Antonius F.W.; Huber, Robert; van Soest, Gijs

2015-01-01

Cardiac motion artifacts, non-uniform rotational distortion and undersampling affect the image quality and the diagnostic impact of intravascular optical coherence tomography (IV-OCT). In this study we demonstrate how these limitations of IV-OCT can be addressed by using an imaging system that we called “Heartbeat OCT”, combining a fast Fourier Domain Mode Locked laser, fast pullback, and a micromotor actuated catheter, designed to examine a coronary vessel in less than one cardiac cycle. We acquired in vivo data sets of two coronary arteries in a porcine heart with both Heartbeat OCT, working at 2.88 MHz A-line rate, 4000 frames/s and 100 mm/s pullback speed, and with a commercial system. The in vivo results show that Heartbeat OCT provides faithfully rendered, motion-artifact free, fully sampled vessel wall architecture, unlike the conventional IV-OCT data. We present the Heartbeat OCT system in full technical detail and discuss the steps needed for clinical translation of the technology. PMID:26713214

PMN-PT Single-Crystal High-Frequency Kerfless Phased Array

PubMed Central

Chen, Ruimin; Cabrera-Munoz, Nestor E.; Lam, Kwok Ho; Hsu, Hsiu-sheng; Zheng, Fan; Zhou, Qifa; Shung, K. Kirk

2015-01-01

This paper reports the design, fabrication, and characterization of a miniature high-frequency kerfless phased array prepared from a PMN-PT single crystal for forward-looking intravascular or endoscopic imaging applications. After lapping down to around 40 μm, the PMN-PT material was utilized to fabricate 32-element kerfless phased arrays using micromachining techniques. The aperture size of the active area was only 1.0 × 1.0 mm. The measured results showed that the array had a center frequency of 40 MHz, a bandwidth of 34% at −6 dB with a polymer matching layer, and an insertion loss of 20 dB at the center frequency. Phantom images were acquired and compared with simulated images. The results suggest that the feasibility of developing a phased array mounted at the tip of a forward-looking intravascular catheter or endoscope. The fabricated array exhibits much higher sensitivity than PZT ceramic-based arrays and demonstrates that PMN-PT is well suited for this application. PMID:24859667

Linear-regression convolutional neural network for fully automated coronary lumen segmentation in intravascular optical coherence tomography.

PubMed

Yong, Yan Ling; Tan, Li Kuo; McLaughlin, Robert A; Chee, Kok Han; Liew, Yih Miin

2017-12-01

Intravascular optical coherence tomography (OCT) is an optical imaging modality commonly used in the assessment of coronary artery diseases during percutaneous coronary intervention. Manual segmentation to assess luminal stenosis from OCT pullback scans is challenging and time consuming. We propose a linear-regression convolutional neural network to automatically perform vessel lumen segmentation, parameterized in terms of radial distances from the catheter centroid in polar space. Benchmarked against gold-standard manual segmentation, our proposed algorithm achieves average locational accuracy of the vessel wall of 22 microns, and 0.985 and 0.970 in Dice coefficient and Jaccard similarity index, respectively. The average absolute error of luminal area estimation is 1.38%. The processing rate is 40.6 ms per image, suggesting the potential to be incorporated into a clinical workflow and to provide quantitative assessment of vessel lumen in an intraoperative time frame. (2017) COPYRIGHT Society of Photo-Optical Instrumentation Engineers (SPIE).

The significance of variations in immunoreactive and clottable fibrinogen in health and following thrombosis

PubMed Central

Wolf, P.; Farrell, G. W.; Walton, K. W.

1972-01-01

In individuals in a steady state of fibrinogen metabolism, immunoreactive and clottable fibrinogen estimates of plasma fibrinogen show close agreement. These estimates also detect any increase of plasma fibrinogen (due to increased synthesis) following metabolic stresses but in certain circumstances discrepancies between immunoreactive and clottable fibrinogen values occur which are of diagnostic assistance. During extensive thrombosis, circulating `cryoprofibrin' (fibrin intermediates) may be formed. These fail to give full quantitative immunodiffusion reactions with antifibrinogen. Values for immunoreactive are therefore lower than for clottable fibrinogen. When intravascular catabolism (due to plasmin action) accompanies increased synthesis, since some of the molecular breakdown products of fibrin or fibrinogen react with antifibrinogen but are not clottable, immunoreactive values exceed those for clottable fibrinogen. This discrepancy is therefore an indicator of thrombolysis. Each discrepancy in turn may be encountered during the alternating predominance of thrombosis or thrombolysis in vivo: (a) physiologically, in association with the menstrual cycle; (b) pathologically, following surgical operations or extensive intravascular thrombosis. Images PMID:4259368

The sliding rail system (monorail): description of a new technique for intravascular instrumentation and its application to coronary angioplasty.

PubMed

Bonzel, T; Wollschläger, H; Kasper, W; Meinertz, T; Just, H

1987-01-01

The sliding rail technique is a new technique for intravascular instrumentation, especially coronary stenosis dilatation. The so-called monorail balloon catheter is the first device which can be used according to this technique. The monorail catheter has a single lumen shaft and only a short central tube within the distal balloon part. With the guidewire inserted into the tube, the balloon can be advanced or retracted on the guidewire as on a sliding rail. The most relevant improvements for coronary dilatation are steerability, contrast flow and rapid and easy exchangeability of balloon catheters and other intracoronary devices. These characteristics are felt to result in a more simple and time- and fluoroscopy-saving dilatation procedure. A special transfusion catheter may also improve procedural safety. The first clinical results in 69 patients with a success rate of 96%, an emergency bypass rate of two patients (one infarction) and a stenosis improvement of 58% confirm the theoretically conceived advantages.

Pathology in rabbits treated with leukocyte-degraded meningococci in combination with meningococcal endotoxin.

PubMed Central

DeVoe, I W; Gilka, F; Gilchrist, J E; Yu, E

1977-01-01

The effects of a preparative dose of the leukocyte egesta containing degraded meningococci and a provocative dose of the meningococcal lipopolysaccharide on development of pathological lesions associated with disseminated intravascular coagulation were studied in tissues of 32 rabbits. These effects were compared with effects of a single dose of meningococcal lipopolysaccharide as well as leukocyte egesta containing degraded Staphylococcus epidermidis. Rabbits injected subcutaneously with egesta containing degraded meningococci followed after 12 h with meningococcal endotoxin (intravenously) exhibited heterophilic leukocytosis and disseminated intravascular coagulation mainly in the pulmonary capillaries and venules; focal necroses occurred in myocardium, lungs, and liver, whereas, cortical renal necrosis developed in lethal cases. Similar lesions, however, but less severe and with less frequency, developed even after a single dose of meningococcal endotoxin or after endotoxin that followed a dose of supernatant fluid from normal leukocytes. Our findings suggest that meningococcal material from polymorphonuclear degradation plays a role in the pathology characteristic of meningococcal septicemia. Images PMID:406202

Successful renal transplantation from a brain-dead deceased donor with head injury, disseminated intravascular coagulation and deranged renal functions.

PubMed

Ghuge, P P; Kute, V B; Vanikar, A V; Gumber, M R; Gera, D N; Patel, H V; Shah, P R; Modi, P R; Shah, V R; Trivedi, H L

2013-11-01

Deceased donors (DDs) with the brain death due to head injury are the major source of organs for transplantation. The incidence of post-head injury disseminated intravascular coagulation (DIC) ranges from 24% to 50%. Many centers do not accept organs from donors with DIC due to increased risk of primary graft non-function and/or high chances of morbidity/mortality. We performed two successful renal transplants from a DD with head injury with DIC and deranged renal function. One of the recipients developed transient thrombocytopenia, but there was no evidence of DIC or delayed graft functions in either of the recipients. Over a follow-up of 1 month, both are doing well with stable graft function and hematological profile. Thus, a carefully selected DD with severe DIC even with deranged renal function is not a contraindication for organ donation if other risk factors for primary non-function are excluded. This approach will also help in overcoming organ shortage.

Fluid therapy and the hypovolemic microcirculation.

PubMed

Gruartmoner, G; Mesquida, J; Ince, Can

2015-08-01

In shock states, optimizing intravascular volume is crucial to promote an adequate oxygen delivery to the tissues. Our current practice in fluid management pivots on the Frank-Starling law of the heart, and the effects of fluids are measured according to the induced changes on stroke volume. The purpose of this review is to evaluate the boundaries of current macrohemodynamic approach to fluid administration, and to introduce the microcirculatory integration as a fundamental part of tissue perfusion monitoring. Macrocirculatory changes induced by volume expansion are not always coupled to proportional changes in microcirculatory perfusion. Loss of hemodynamic coherence limits the value of guiding fluid therapy according to macrohemodynamics, and highlights the importance of evaluating the ultimate target of volume administration, the microcirculation. Current approach to intravascular volume optimization is made from a macrohemodynamic perspective. However, several situations wherein macrocirculatory and microcirculatory coherence is lost have been described. Future clinical trials should explore the usefulness of integrating the microcirculatory evaluation in fluid optimization.

Pharmacokinetics and acetylation of sulfamethoxazole in turbot Scophthalmus maximus after intravascular administration

NASA Astrophysics Data System (ADS)

Chang, Zhiqiang; Liu, Fei; Lian, Chun'ang; Zhai, Qianqian; Li, Jian

2016-07-01

The pharmacokinetic profiles and sulfamethoxazole (SMX) acetylation process in turbot reared at 18°C were investigated. Either SMX (parent drug) or its acetylized metabolite, N4-acetylsulfamethoxazole (AcSMX), was administered intravascularly to turbot at a dosage of 50 mg/kg BW. Serum concentrations of the parent drug and its metabolite were both measured by HPLC, and the changes in concentration over time were analyzed in two- and non-compartment models because SMX treatment produced multiple peaks. The results demonstrated that the elimination half-life of the parent drugs, SMX and AcSMX, were 159.2 and 5.9 h, respectively. The apparent volume of distribution was 0.2 and 0.8 L/kg, and the clearance was 0.038 and 0.222 L/(h·kg), for SMX and AcSMX, respectively. SMX acetylation in turbot was 2.8%, and the deacetylation of AcSMX was 0.2%. These findings may be useful in optimizing SMX dosage regimens in turbot aquaculture.

The effects of electric current on bacteria colonising intravenous catheters.

PubMed

Liu, W K; Tebbs, S E; Byrne, P O; Elliott, T S

1993-11-01

The effect of a direct electric current (10 microA) on the growth of Staphylococcus aureus, Staphylococcus epidermidis, Escherichia coli, Klebsiella pneumoniae and Proteus mirabilis was investigated. When the ends of negatively-charged intravascular catheters were placed in nutrient agar seeded with bacteria, circular zones of inhibition of bacterial growth were observed around the catheters. The zones ranged from 6 to 16 mm in diameter according to the organism under test. Zones of inhibition were not produced around positively-charged catheters. Bacteria colonising the surfaces of catheters were similarly affected by the application of a 10 microA electric current. A negative electric current applied to colonised catheters for 4 to 24 h significantly reduced the number of adherent viable organisms as compared to controls. The results demonstrated that a constant electric current of low amperage might be used to reduce bacterial colonisation of intravascular catheters. This may offer a novel means of protecting catheters and other prosthetic devices from associated sepsis in vivo.

Intravascular optical imaging of high-risk plaques in vivo by targeting macrophage mannose receptors

NASA Astrophysics Data System (ADS)

Kim, Ji Bak; Park, Kyeongsoon; Ryu, Jiheun; Lee, Jae Joong; Lee, Min Woo; Cho, Han Saem; Nam, Hyeong Soo; Park, Ok Kyu; Song, Joon Woo; Kim, Tae Shik; Oh, Dong Joo; Gweon, Daegab; Oh, Wang-Yuhl; Yoo, Hongki; Kim, Jin Won

2016-03-01

Macrophages mediate atheroma expansion and disruption, and denote high-risk arterial plaques. Therefore, they are substantially gaining importance as a diagnostic imaging target for the detection of rupture-prone plaques. Here, we developed an injectable near-infrared fluorescence (NIRF) probe by chemically conjugating thiolated glycol chitosan with cholesteryl chloroformate, NIRF dye (cyanine 5.5 or 7), and maleimide-polyethylene glycol-mannose as mannose receptor binding ligands to specifically target a subset of macrophages abundant in high-risk plaques. This probe showed high affinity to mannose receptors, low toxicity, and allowed the direct visualization of plaque macrophages in murine carotid atheroma. After the scale-up of the MMR-NIRF probe, the administration of the probe facilitated in vivo intravascular imaging of plaque inflammation in coronary-sized vessels of atheromatous rabbits using a custom-built dual-modal optical coherence tomography (OCT)-NIRF catheter-based imaging system. This novel imaging approach represents a potential imaging strategy enabling the identification of high-risk plaques in vivo and holds promise for future clinical implications.

On the validity of the dispersion model of hepatic drug elimination when intravascular transit time densities are long-tailed.

PubMed

Weiss, M; Stedtler, C; Roberts, M S

1997-09-01

The dispersion model with mixed boundary conditions uses a single parameter, the dispersion number, to describe the hepatic elimination of xenobiotics and endogenous substances. An implicit a priori assumption of the model is that the transit time density of intravascular indicators is approximately by an inverse Gaussian distribution. This approximation is limited in that the model poorly describes the tail part of the hepatic outflow curves of vascular indicators. A sum of two inverse Gaussian functions is proposed as an alternative, more flexible empirical model for transit time densities of vascular references. This model suggests that a more accurate description of the tail portion of vascular reference curves yields an elimination rate constant (or intrinsic clearance) which is 40% less than predicted by the dispersion model with mixed boundary conditions. The results emphasize the need to accurately describe outflow curves in using them as a basis for determining pharmacokinetic parameters using hepatic elimination models.

Novel PMN-PT free standing film for high frequency (80MHz) intravascular ultrasonic imaging

PubMed Central

Li, Xiang; Zhou, Qifa; Shung, K. Kirk; Shih, Wei-Heng; Shih, Wan Y.

2011-01-01

[Pb(Mg1/3Nb2/3)O3]0.63[PbTiO3]0.37 (PMN-PT) free standing film of comparable piezoelectric property to bulk PMN-PT with a thickness of 33 μm has been fabricated using a modified precursor coating approach. At 1 KHz, the dielectric constant and loss were 4,160 and 0.0291, respectively. The remnant polarization and coercive field were 28 μC/cm2 and 18.43 kV/cm. The electromechanical coupling coefficient kt was measured to be 0.55, which was close to that of bulk PMN-PT single crystal material. A high frequency (80 MHz) miniature ultrasonic transducer with high sensitivity was fabricated from this film. In vitro imaging of a rabbit aorta was performed to demonstrate the application of this material to intravascular ultrasound imaging at 80 MHz. Compared to a 35 MHz ultrasonic image, the 80 MHz image showed superior resolution and contrast. PMID:22083761

Photothermal strain imaging

NASA Astrophysics Data System (ADS)

Choi, Changhoon; Ahn, Joongho; Jeon, Seungwan; Kim, Chulhong

2017-07-01

Vulnerable plaques are the major cause of cardiovascular disease, but they are difficult to detect with conventional intravascular imaging techniques. Techniques are needed to identify plaque vulnerability based on the presence of lipids in plaque. Thermal strain imaging (TSI) is an imaging technique based on ultrasound (US) wave propagation speed, which varies with the medium temperature. In TSI, the strain that occurs during tissue temperature change can be used for lipid detection because it has a different tendency depending on the type of tissue. Here, we demonstrate photothermal strain imaging (pTSI) using an intravascular ultrasound catheter. pTSI is performed by slightly and selectively heating lipid using a relatively inexpensive continuous laser source. We applied a speckle-tracking algorithm to US B-mode images for strain calculations. As a result, the strain produced in porcine fat was different from the strain produced in water-bearing gelatin phantom, which made it possible to distinguish the two. This suggests that pTSI could potentially be a way of differentiating lipids in coronary artery.

Chronic intravascular coagulation associated with chronic myelocytic leukemia. Use of heparin in connection with a surgical procedure.

PubMed

German, H J; Smith, J A; Lindenbaum, J

1976-10-01

A women with Philadelphia chromosome-positive chronic myelocytic leukemia lived nearly 12 years from the time of diagnosis. During most of this period she received no therapy, and marked cyclic oscillations in the white blood cell count were documented. The last two years of her illness were marked by a hemorrhagic disorder associated with hypofibrinogenemia, thrombocytopenia, increased plasma fibrinopeptide A concentration and markedly elevated serum levels of fibrin degradation products. The coagulation disorder was rapidly reversible on several occasions with heparin therapy. After treatment with heparin and platelet transfusions, the patient underwent successful resection of a large ovarian cyst with excellent hemostasis during the procedure. Postoperatively, the administration of heparin and platelets was discontinued and a large wound hematoma developed. After resumption of therapy with heparin and platelets, the remainder of her postoperative course was uneventful. The literature on the subject is reviewed and tentative guidelines are offered concerning the management of patients with intravascular coagulation who require diagnostic or therapeutic surgical procedures.

Three Cases of Intravascular Large B-Cell Lymphoma Detected in a Biopsy of Skin Lesions.

PubMed

Arai, Takashi; Kato, Yukihiko; Funaki, Maki; Shimamura, Sanae; Yokogawa, Naoto; Sugii, Syoji; Tsuboi, Ryoji

2016-01-01

Intravascular large B-cell lymphoma (IVL) is a rare subtype of extranodal malignant lymphoma. The proliferation of neoplastic B cells within small blood vessels causes eruptions and other symptoms in a variety of organs. The random skin biopsy is useful for diagnosing this condition in its early stages. In order to assess the diagnostic utility of this method, we examined 3 cases with the aim of comparing the occurrence of tumor cells in lesional and healthy-looking skin by performing a random skin biopsy of 32 separate sites. Our findings from the total of 32 biopsy specimens collected from the 3 cases indicated that 16 of the 17 sites on the lesional skin and 1 of the 15 sites on the healthy-looking skin were positive for neoplastic cells. This finding suggested that IVL cells occurred more frequently in the lesional skin than in the healthy-looking skin. © 2016 S. Karger AG, Basel.

Human pharmacokinetics of iohexol. A new nonionic contrast medium

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

Olsson, B.; Aulie, A.; Sveen, K.

1983-03-01

The pharmacokinetics of iohexol, a new nonionic, water-soluble contrast medium, have been determined after intravenous injection in 20 healthy volunteers, at four different dose levels (125-500 mg I/kg). The apparent volume of distribution was 0.27 1/kg, indicating distribution in the extracellular water. The biologic half-life was 121 minutes, comparable with that of other intravascular contrast media. Iohexol was excreted completely unmetabolized in the urine, with a 100% recovery 24 hours after injection. A comparison of iohexol and chromium-51 (/sup 51/Cr)-EDTA clearances indicates that iohexol is mainly excreted by glomerular filtration. The /sup 51/Cr-EDTA clearance was the same when injected separatelymore » and concomitantly with iohexol, indicating that glomerular filtration rate is not affected by iohexol. No dose dependency was observed in the investigated parameters t1/2 alpha, t1/2 beta, Vd, ClT or ClR. Iohexol pharmacokinetics are in correspondence with previously reported data on intravascular contrast media.« less

Oxygen-induced frequency shifts in hyperoxia: a significant component of BOLD signal.

PubMed

Song, Youngkyu; Cho, Gyunggoo; Chun, Song-I; Baek, Jin Hee; Cho, HyungJoon; Kim, Young Ro; Park, Sung Bin; Kim, Jeong Kon

2014-07-01

In comparison to the well-documented significance of intravascular deoxyhemoglobin (deoxyHgb), the effects of dissolved oxygen on the blood-oxygen-level-dependent (BOLD) signal have not been widely reported. Based on the fact that the prolonged inspiration of high oxygen fraction gas can result in up to a sixfold increase of the baseline tissue oxygenation, the current study focused on the influence of dissolved oxygen on the BOLD signal during hyperoxia. As results, our in vitro study revealed that the r1 and r2 (relaxivities) of the oxygen-treated serum were 0.22 mM(-1) · s(-1) and 0.19 mM(-1) · s(-1) , respectively. In an in vivo experiment, hyperoxic respiration induced negative BOLD contrast (i.e. signal decrease) in 18-42% of measured brain regions, voxels with accompanying significant decreases in both the T(*)2 (-12.1% to -19.4%) and T1 (-5.8% to -3.3%) relaxation times. In contrast, the T(*)2 relaxation time significantly increased (11.2% to 14.0%) for the voxels displaying positive BOLD contrast (in 41-50% of the measured brain), which reflected a hyperoxygenation-induced reduction in tissue deoxyHgb concentration. These data imply that hyperoxia-driven BOLD signal changes are primarily determined by the counteracting effects of extravascular oxygen and intravascular deoxyHgb. Oxygen-induced magnetic susceptibility was further demonstrated by the study of 1 min hypoxia, which induced BOLD signal changes opposite to those under hyperoxia. Vasoconstriction was more common in voxels with negative BOLD contrast than in voxels with positive contrast (% change of blood volume, -9.8% to -12.8% versus 2.0% to 2.2%), which further suggests that negative BOLD contrast is mainly evoked by an increase in extravascular oxygen concentration. Conclusively, frequency shifts, which are induced by the accumulation of oxygen molecules and associated magnetic field inhomogeneity, are a significant source of the negative BOLD contrast during hyperoxia. Copyright © 2014 John Wiley & Sons, Ltd.

Approach for chronic total occlusion with intravascular ultrasound-guided reverse controlled antegrade and retrograde tracking technique: single center experience.

PubMed

Dai, Jian; Katoh, Osamu; Kyo, Eisho; Tsuji, Takafumi; Watanabe, Satoshi; Ohya, Hidefumi

2013-10-01

Controlled antegrade and retrograde subintimal tracking (CART) or reverse CART techniques is the final step for percutaneous revascularization of coronary chronic total occlusion (CTO), but it still represents technical challenges and risk in interventional procedures. Our purpose was to utilize intravascular ultrasound (IVUS)-guided reverse CART approach for percutaneous revascularization of CTO in our heart center, focusing on its safety, efficacy, and latest technical developments. From November 2006 to November 2012, 49 patients with CTO failed to antegrade and/or retrograde percutaneous revascularization of CTO from true lumen to true lumen were enrolled in and underwent IVUS guided reverse CART approach. The mean J-CTO score of cases was 2.5. IVUS guidance was successfully implemented in 95.9%; IVUS identified that 61.7% of retrograde wires were located at intimal space, and 59.5% of antegrade wires were located at subintimal space. A Corsair channel dilator was used in 77.6% of cases. The success rates of technique and procedure were 95.9% and 93.9%, respectively; the technical minor complications were observed in 10.2% of cases, without significant clinic outcomes; 2.0% of cases occurred with a major adverse cardiac event of non-ST-elevation myocardial infarction; and no case occurred with target vessel revascularization or death. The mean length of stent implanted in a single CTO vessel was 51.3 mm. No patient appeared with radiation dermatitis and contrast-induced rise of creatinine. IVUS guided reverse CART approach is effective and safe for percutaneous revascularization of complex CTO, with a high success and a low complication rate. It is feasible to develop this approach for percutaneous revascularization of complex CTO. However, suitable case selection and lately device handling by experienced operators are the crucial points of success. © 2013, Wiley Periodicals, Inc.

Inhalation of Whole Diesel Exhaust but not Gas-Phase Components Affects In Vitro Platelet Aggregation in Hypertensive Rats

EPA Science Inventory

Rationale: Intravascular thrombosis and platelet aggregation are enhanced following exposure to diesel exhaust (DE) and other respirable particulate matter; however, the roles of endothelial and circulating mediators on platelet aggregation remain unclear. We hypothesized that ad...

The vascular supply of the thymus in the guinea-pig and pig

PubMed Central

Olson, I. A.; Poste, Mary E.

1973-01-01

A study of the blood supply of the thymus using intravascular carbon or silver shows that the pig and guinea-pig possess a more extensive vascular system than the current model taken from work on the mouse. ImagesFIG. 1FIG. 2FIG. 3 PMID:4120933

A Novel Swine Model for Evaluation of Potential Intravascular Hemostatic Agents

DTIC Science & Technology

2007-06-01

bovine polymerized hemoglobin on coagulation in controlled hemorrhagic shock in swine. Shock 24:145–152. 2. Bellamy RF. 1984. The causes of death in...WZ, Pusateri AE, Uscilowicz JM, Delgado AV, Holcomb JB. 2005. Independent contributions of hypothermia and acidosis to coagulopathy in swine. J

Quantitative assessment of reflux in commercially available needle-free IV connectors.

PubMed

Hull, Garret J; Moureau, Nancy L; Sengupta, Shramik

2018-01-01

Blood reflux is caused by changes in pressure within intravascular catheters upon connection or disconnection of a syringe or intravenous tubing from a needle-free connector (NFC). Changes in pressure, differing with each brand of NFC, may result in fluid movement and blood reflux that can contribute to intraluminal catheter occlusions and increase the potential for central-line associated bloodstream infections (CLABSI). In this study, 14 NFC brands representing each of the four market-categories of NFCs were selected for evaluation of fluid movement occurring during connection and disconnection of a syringe. Study objectives were to 1) theoretically estimate amount of blood reflux volume in microliters (μL) permitted by each NFC based on exact component measurements, and 2) experimentally measure NFC volume of fluid movement for disconnection reflux of negative, neutral and anti-reflux NFC and fluid movement for connection reflux of positive displacement NFC. The results demonstrated fluid movement/reflux volumes of 9.73 μL to 50.34 μL for negative displacement, 3.60 μL to 10.80 μL for neutral displacement, and 0.02 μL to 1.73 μL for pressure-activated anti-reflux NFC. Separate experiment was performed measuring connection reflux of 18.23 μL to 38.83 μL for positive displacement NFC connectors. This study revealed significant differences in reflux volumes for fluid displacement based on NFC design. While more research is needed on effects of blood reflux in catheters and NFCs, results highlight the need to consider NFCs based on performance of individual connector designs, rather than manufacturer designation of positive, negative and neutral marketing categories for NFCs without anti-reflux mechanisms.

Ancillary procedures necessary for translational research in experimental craniomaxillofacial surgery

PubMed Central

Al Rakan, Mohammed; Shores, Jaimie T.; Bonawitz, Steve; Santiago, Gabriel; Christensen, Joani M.; Grant, Gerald; Murphy, Ryan J.; Basafa, Ehsan; Armand, Mehran; Otovic, Pete; Eller, Sue; Brandacher, Gerald; Gordon, Chad R.

2014-01-01

Introduction Swine are often regarded as having analogous facial skeletons to humans and therefore serve as an ideal animal model for translational investigation. However, there's a dearth of literature describing the pertinent ancillary procedures required for craniomaxillofacial research. With this in mind, our objective was to evaluate all necessary procedures required for peri-operative management and animal safety related to experimental craniomaxillofacial surgical procedures such as orthotopic, maxillofacial transplantation. Methods Miniature swine (n=9) were used to investigate peri-operative airway management, methods for providing nutrition, and long-dwelling intravenous access. Flap perfusion using near-infrared laser angiography and facial nerve assessment with EMG were explored. Results Bivona(R) tracheostomy was deemed appropriate versus Shiley since soft, wire-reinforced tubing reduced the incidence of tracheal necrosis. PEG tube, as opposed to esophagostomy, provided a reliable route for post-operative feeding. Femoral venous access with dorsal tunneling proved to be an ideal option being far from pertinent neck vessels. Laser angiography was beneficial for real-time evaluation of graft perfusion. Facial EMG techniques for tracing capture were found most optimal using percutaneous leads near the oral commissure. Experience shows that ancillary procedures are critical and malpositioning of devices may lead to irreversible sequelae with premature animal death. Conclusion Face-jaw-teeth transplantation in swine is a complicated procedure which demands special attention to airway, feeding, and intravascular access. It is critical that each ancillary procedure be performed by a dedicated team familiar with relevant anatomy and protocol. Emphasis should be placed on secure skin-level fixation for all tube/lines to minimize risk of dislodgement. A reliable veterinarian team is invaluable and critical for long-term success. PMID:25377964

Increased CD39 Nucleotidase Activity on Microparticles from Patients with Idiopathic Pulmonary Arterial Hypertension

PubMed Central

Visovatti, Scott H.; Hyman, Matthew C.; Bouis, Diane; Neubig, Richard; McLaughlin, Vallerie V.; Pinsky, David J.

2012-01-01

Background Idiopathic pulmonary arterial hypertension (IPAH) is a devastating disease characterized by increased pulmonary vascular resistance, smooth muscle and endothelial cell proliferation, perivascular inflammatory infiltrates, and in situ thrombosis. Circulating intravascular ATP, ADP, AMP and adenosine activate purinergic cell signaling pathways and appear to induce many of the same pathologic processes that underlie IPAH. Extracellular dephosphorylation of ATP to ADP and AMP occurs primarily via CD39 (ENTPD1), an ectonucleotidase found on the surface of leukocytes, platelets, and endothelial cells [1]. Microparticles are micron-sized phospholipid vesicles formed from the membranes of platelets and endothelial cells. Objectives: Studies here examine whether CD39 is an important microparticle surface nucleotidase, and whether patients with IPAH have altered microparticle-bound CD39 activity that may contribute to the pathophysiology of the disease. Methodology/ Principal Findings Kinetic parameters, inhibitor blocking experiments, and immunogold labeling with electron microscopy support the role of CD39 as a major nucleotidase on the surface of microparticles. Comparison of microparticle surface CD39 expression and nucleotidase activity in 10 patients with advanced IPAH and 10 healthy controls using flow cytometry and thin layer chromatograph demonstrate the following: 1) circulating platelet (CD39+CD31+CD42b+) and endothelial (CD39+CD31+CD42b−) microparticle subpopulations in patients with IPAH show increased CD39 expression; 2) microparticle ATPase and ADPase activity in patients with IPAH is increased. Conclusions/ Significance We demonstrate for the first time increased CD39 expression and function on circulating microparticles in patients with IPAH. Further research is needed to elucidate whether these findings identify an important trigger for the development of the disease, or reflect a physiologic response to IPAH. PMID:22792409

Assessment of incomplete clipping of aneurysms intraoperatively by a near-infrared indocyanine green-video angiography (Niicg-Va) integrated microscope.

PubMed

Imizu, S; Kato, Y; Sangli, A; Oguri, D; Sano, H

2008-08-01

The objective of this article was to assess the clinical use and the completeness of clipping with total occlusion of the aneurysmal lumen, real-time assessment of vascular patency in the parent, branching and perforating vessels, intraoperative assessment of blood flow, image quality, spatial resolution and clinical value in difficult aneurysms using near infrared indocyanine green video angiography integrated on to an operative Pentero neurosurgical microscope (Carl Zeiss, Oberkochen Germany). Thirteen patients with aneurysms were operated upon. An infrared camera with near infrared technology was adapted on to the OPMI Pentero microscope with a special filter and infrared excitation light to illuminate the operating field which was designed to allow passage of the near infrared light required for excitation of indocyanine green (ICG) which was used as the intravascular marker. The intravascular fluorescence was imaged with a video camera attached to the microscope. ICG fluorescence (700-850 nm) from a modified microscope light source on to the surgical field and passage of ICG fluorescence (780-950 nm) from the surgical field, back into the optical path of the microscope was used to detect the completeness of aneurysmal clipping Incomplete clipping in three patients (1 female and 2 males) with unruptured complicated aneurysms was detected using indocyanine green video angiography. There were no adverse effects after injection of indocyanine green. The completeness of clipping was inadequately detected by Doppler ultrasound miniprobe and rigid endoscopy and was thus complemented by indocyanine green video angiography. The operative microscope-integrated ICG video angiography as a new intraoperative method for detecting vascular flow, was found to be quick, reliable, cost-effective and possibly a substitute or adjunct for Doppler ultrasonography or intraoperative DSA, which is presently the gold standard. The simplicity of the method, the speed with which the investigation can be performed, the quality of the images, and the outcome of surgical procedures have all reduced the need for angiography. This technique may be useful during routine aneurysm surgery as an independent form of angiography and/or as an adjunct to intraoperative or postoperative DSA.

Limits of intravascular contrast extravasation on computed tomography scan to define the need for pelvic angioembolization in pelvic blunt trauma: a specific assessment on the risk of false-positives.

PubMed

Ramin, Séverin; Hermida, Margaux; Millet, Ingrid; Murez, Thibault; Monnin, Valérie; Hamoui, Mazen; Capdevila, Xavier; Charbit, Jonathan

2018-06-12

The objective was to assess the predictive performance of different intravascular contrast extravasation (ICE) characteristics for need for pelvic transarterial embolization (TAE) to determine the risk factors of false-positives. A retrospective study was performed in our trauma center between 2010 and 2015. All severe trauma patients with pelvic fracture were included. Pelvic ICE characteristics on computed tomography (CT) scan were studied: arterial (aSICE), portal surface (pSICE), and extension (exSICE) anatomic relationships. The overall predictive performance of ICE surfaces for pelvic TAE was analyzed using receiver operating characteristic curves. The analysis focused on risk factors for false-positives. Among 311 severe trauma patients with pelvic ring fracture (mean age, 42 ± 19 years, mean Injury Severity Score, 27 ± 19), 94 (30%) had at least one pelvic ICE on the initial CT scan. Patients requiring pelvic TAE had significantly larger aSICE and pSICE than others (P=0.001 and P=0.035, respectively). The overall ability of ICE surfaces to predict pelvic TAE was modest (aSICE AUC, 0.76 [95% CI, 0.64-0.90]; P=0.011) or non-significant (pSICE and exSICE). The high-sensitivity threshold was defined as aSICE ≥20 mm. Using this threshold, 76% of patients were false-positives. Risk factors for false-positives were: admission systolic blood pressure ≥90 mmHg (63% versus 20%; P=0.03) and low transfusion needs (63% versus 10%; P=0.009), extravasation in contact with complex bone fracture (78% versus 30%; P=0.008) or the absence of a direct relationship between extravasation and a large retroperitoneal hematoma (100% versus 38%; P<0.001). A significant pelvic ICE during the arterial phase does not guarantee the need for pelvic TAE. Three-quarter of patients with aSICE ≥20 mm did not need pelvic TAE. Several complementary CT scan criteria will help to identify this risk of false-positives to determine adequate hemostatic pelvic procedures.This work is an original article, retrospective study Level II of evidence, Therapeutic/Critical Care management.

Nosocomial endocarditis caused by Corynebacterium amycolatum and other nondiphtheriae corynebacteria.

PubMed

Knox, Karen L; Holmes, Alison H

2002-01-01

The nondiphtheriae corynebacteria are uncommon but increasingly recognized as agents of endocarditis in patients with underlying structural heart disease or prosthetic-valves. We describe three cases of nosocomial endocarditis caused by nondiphtheriae corynebacteria, including the first reported case of Corynebacterium amycolatum, endocarditis. These all occurred in association with indwelling intravascular devices.

21 CFR 880.5965 - Subcutaneous, implanted, intravascular infusion port and catheter.

Code of Federal Regulations, 2014 CFR

2014-04-01

... HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES GENERAL HOSPITAL AND PERSONAL USE DEVICES General... and medications and the sampling of blood. The device consists of a portal body with a resealable... device is available in various profiles and sizes and can be of a single or multiple lumen design. (b...

21 CFR 880.5965 - Subcutaneous, implanted, intravascular infusion port and catheter.

Code of Federal Regulations, 2013 CFR

2013-04-01

... HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES GENERAL HOSPITAL AND PERSONAL USE DEVICES General... and medications and the sampling of blood. The device consists of a portal body with a resealable... device is available in various profiles and sizes and can be of a single or multiple lumen design. (b...

21 CFR 880.5965 - Subcutaneous, implanted, intravascular infusion port and catheter.

Code of Federal Regulations, 2012 CFR

2012-04-01

... HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES GENERAL HOSPITAL AND PERSONAL USE DEVICES General... and medications and the sampling of blood. The device consists of a portal body with a resealable... device is available in various profiles and sizes and can be of a single or multiple lumen design. (b...

Toxicologic and Analytical Studies with T-2 and Related Trichothecene Mycotoxins

DTIC Science & Technology

1983-03-01

study is to assess the nature of T-2 induced shock using intravascular and inhalation routes of administration. To accomplish this goal, we investi...this data. In addition, a bone marrow response is absent as evidenced by the lack of significant increase in irm- nature neutrophils (band cells). The

Hypercalcemia and parathyroid hormone-related protein in a dog with undifferentiated nasal carcinoma.

PubMed Central

Anderson, G M; Lane, I; Fischer, J; Lopez, A

1999-01-01

Hypercalcemia was discovered in a 7-year-old, castrated male basset hound with a suspected nasal tumor. The dog died the day after admission and nasal carcinoma and disseminated intravascular coagulation were diagnosed on postmortem. Detectable levels of serum PTHrP support a diagnosis of hypercalcemia of malignancy. PMID:10340096

Intravascular large B-cell lymphoma diagnosed by FDG-PET/CT and endometrial biopsy.

PubMed

Takeoka, Yasunobu; Inaba, Akiko; Fujitani, Yotaro; Kosaka, Saori; Yamamura, Ryosuke; Senzaki, Hideto; Okamura, Terue; Ohta, Kensuke

2011-11-01

Intravascular large B-cell lymphoma (IVLBCL) is a rare form of non-Hodgkin's lymphoma characterized by a proliferation of tumor cells within the lumina of small to medium-sized vessels. Because there are few or no concomitant solid lesions, a diagnosis of IVLBCL usually cannot be established by CT or MR imaging. Herein, we describe a case of IVLBCL involving the uterus, in which (18)F-fluorodeoxyglucose positron emission tomography/computed tomography (FDG-PET/CT) was useful for diagnosis. A 47-year-old woman was referred to our hospital because of fever and anemia. Laboratory examination demonstrated anemia and thrombocytopenia. Bone marrow aspiration and biopsy showed hemophagocytosis without involvement of lymphoma cells. Random skin biopsy did not demonstrate lymphoma involvement. FDG-PET/CT imaging showed FDG accumulation in the uterus. MR imaging demonstrated uterine leiomyoma only. Based on these findings, uterine endometrial biopsy was performed and histological diagnosis of IVLBCL involving the uterus was established. She received 6 courses of R-CHOP therapy and high-dose chemotherapy followed by autologous peripheral blood stem cell transplantation. At present, she remains in complete remission after 33 months.

Cutting edge: control of Mycobacterium tuberculosis infection by a subset of lung parenchyma-homing CD4 T cells.

PubMed

Sakai, Shunsuke; Kauffman, Keith D; Schenkel, Jason M; McBerry, Cortez C; Mayer-Barber, Katrin D; Masopust, David; Barber, Daniel L

2014-04-01

Th1 cells are critical for containment of Mycobacterium tuberculosis infection, but little else is known about the properties of protective CD4 T cell responses. In this study, we show that the pulmonary Th1 response against M. tuberculosis is composed of two populations that are either CXCR3(hi) and localize to lung parenchyma or are CX3CR1(hi)KLRG1(hi) and are retained within lung blood vasculature. M. tuberculosis-specific parenchymal CD4 T cells migrate rapidly back into the lung parenchyma upon adoptive transfer, whereas the intravascular effectors produce the highest levels of IFN-γ in vivo. Importantly, parenchymal T cells displayed greater control of infection compared with the intravascular counterparts upon transfer into susceptible T cell-deficient hosts. Thus, we identified a subset of naturally generated M. tuberculosis-specific CD4 T cells with enhanced protective capacity and showed that control of M. tuberculosis correlates with the ability of CD4 T cells to efficiently enter the lung parenchyma rather than produce high levels of IFN-γ.

Surfactant effects on the dynamics of an intravascular bubble

NASA Astrophysics Data System (ADS)

Zhang, Jie; Eckmann, David; Ayyaswamy, P. S.

2004-11-01

The effects of a surfactant on the dynamics of gas bubble behavior in the arteriolar vasculature are numerically investigated. The equations for momentum in the bulk fluid (blood) and the bubble, and the convection-diffusion equations for mass transport both in the bulk fluid and on the gas-liquid interface are numerically solved using a front tracking method. Both soluble and insoluble surfactants are considered. The adsorption/desorption dynamics of the soluble surfactant is accurately resolved. For a nearly occluded bubble, a faster rate of depletion of the surfactant from the region adjacent to the wall of the vessel is observed. In several cases studied here, the bulk medium is treated as non-Newtonian (power law, Casson), although the majority of cases treat blood as Newtonian. Results show that the adsorbed surfactant serves to prevent blood proteins and other macromolecules from occupying the interface. This prevents clotting or adhesion of the bubble to the vessel wall. The results obtained have significance in the study of intravascular gas embolism. Supported by NIH R01 HL67986

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

Lee, H.B.; Wexler, J.P.; Scharf, S.C.

The effect of two antihypertensive agents (captopril and prazosin) and of digoxin on the efficiency of Tc-99m binding to RBCs was evaluated in the rat. RBCs were labeled with Tc-99m in vivo in six groups of rats: I-normotensive controls Wistar rat (WR), II-prazosin treated WR, III-spontaneously hypertensive rat (SHR), IV-prazosin-treated SHR, V-digoxin-treated WR, and VI-captopril-treated WR. The percentage of intravascular Tc-99m bound to RBC (%T) and the percentage of injected dose remaining intravascular 5 min after injection (%i.v.) were determined. Mean %T was 94.2, 83.8, 94.9, 86.1, 79.7, and 93.3 for groups I-VI respectively. Mean %I.V. was 96.4, 74.6, 94.9,more » 79.0, 74.4, and 87.4 for groups I-VI respectively. The findings demonstrate a significant reduction of RBC tagging with Tc-99m in rats treated with prazosin and digoxin but not with captopril. The data suggest a potential interference by patient medication with the performance of blood-pool studies.« less

Atrial natriuretic factor increases vascular permeability

NASA Technical Reports Server (NTRS)

Lockette, Warren; Brennaman, Bruce

1990-01-01

An increase in central blood volume in microgravity may result in increased plasma levels of atrial natriuretic factor (ANF). In this study, it was determined whether ANF increases capillary permeability to plasma protein. Conscious, bilaterally nephrectomized male rats were infused with either saline, ANF + saline, or hexamethonium + saline over 2 h following bolus injections of (I-125)-albumin and (C-14)-dextran of similar molecular size. Blood pressure was monitored, and serial determinations of hematocrits were made. Animals infused with 1.0 microg/kg per min ANF had significantly higher hematocrits than animals infused with saline vehicle. Infusion of ANF increased the extravasation of (I-125)-albumin, but not (C-14)-dextran from the intravascular compartment. ANF also induced a depressor response in rats, but the change in blood pressure did not account for changes in capillary permeability to albumin; similar depressor responses induced by hexamethonium were not accompanied by increased extravasation of albumin from the intravascular compartment. ANF may decrease plasma volume by increasing permeability to albumin, and this effect of ANF may account for some of the signs and symptoms of space motion sickness.

Optimizing the beam pattern of a forward-viewing ring-annular ultrasound array for intravascular imaging.

PubMed

Wang, Yao; Stephens, Douglas N; O'Donnell, Matthew

2002-12-01

Intravascular ultrasound (IVUS) imaging systems using circumferential arrays mounted on cardiac catheter tips fire beams orthogonal to the principal axis of the catheter. The system produces high resolution cross-sectional images but must be guided by conventional angioscopy. A real-time forward-viewing array, integrated into the same catheter, could greatly reduce radiation exposure by decreasing angiographic guidance. Unfortunately, the mounting requirement of a catheter guide wire prohibits a full-disk imaging aperture. Given only an annulus of array elements, prior theoretical investigations have only considered a circular ring of point transceivers and focusing strategies using all elements in the highly dense array, both impractical assumptions. In this paper, we consider a practical array geometry and signal processing architecture for a forward-viewing IVUS system. Our specific design uses a total of 210 transceiver firings with synthetic reconstruction for a given 3-D image frame. Simulation results demonstrate this design can achieve side-lobes under -40 dB for on-axis situations and under -30 dB for steering to the edge of a 80 degrees cone.

The Imaging Modulography Technique Revisited for High-Definition Intravascular Ultrasound: Theoretical Framework.

PubMed

Tacheau, Antoine; Le Floc'h, Simon; Finet, Gérard; Doyley, Marvin M; Pettigrew, Roderic I; Cloutier, Guy; Ohayon, Jacques

2016-03-01

Mechanical characterization of atherosclerotic lesions remains an essential step for the detection of vulnerable plaques (VPs). Recently, an intravascular ultrasound (IVUS) elasticity reconstruction method (iMOD) has been tested in vivo by our group. The major limitation of iMOD is the need to estimate the strain field in the entire VP despite attenuated depth penetration signals when using high-definition (HD) IVUS systems. Therefore, an extended iMOD approach (E-iMOD) was designed and applied to coronary lesions of patients imaged in vivo with IVUS. The E-iMOD method (i) quantified necrotic core areas with a mean absolute relative error of 3.5 ± 3.5% and (ii) identified Young's moduli of the necrotic cores and fibrous regions with mean values of 5.7 ± 0.8 kPa and 794.5 ± 22.0 kPa instead of 5 kPa and 800 kPa, respectively. This study demonstrates the potential of the improved HD-IVUS modulography technique E-iMOD to characterize coronary VPs. Copyright © 2016 World Federation for Ultrasound in Medicine & Biology. All rights reserved.

Intravascular optical imaging of high-risk plaques in vivo by targeting macrophage mannose receptors

PubMed Central

Kim, Ji Bak; Park, Kyeongsoon; Ryu, Jiheun; Lee, Jae Joong; Lee, Min Woo; Cho, Han Saem; Nam, Hyeong Soo; Park, Ok Kyu; Song, Joon Woo; Kim, Tae Shik; Oh, Dong Joo; Gweon, DaeGab; Oh, Wang-Yuhl; Yoo, Hongki; Kim, Jin Won

2016-01-01

Macrophages mediate atheroma expansion and disruption, and denote high-risk arterial plaques. Therefore, they are substantially gaining importance as a diagnostic imaging target for the detection of rupture-prone plaques. Here, we developed an injectable near-infrared fluorescence (NIRF) probe by chemically conjugating thiolated glycol chitosan with cholesteryl chloroformate, NIRF dye (cyanine 5.5 or 7), and maleimide-polyethylene glycol-mannose as mannose receptor binding ligands to specifically target a subset of macrophages abundant in high-risk plaques. This probe showed high affinity to mannose receptors, low toxicity, and allowed the direct visualization of plaque macrophages in murine carotid atheroma. After the scale-up of the MMR-NIRF probe, the administration of the probe facilitated in vivo intravascular imaging of plaque inflammation in coronary-sized vessels of atheromatous rabbits using a custom-built dual-modal optical coherence tomography (OCT)-NIRF catheter-based imaging system. This novel imaging approach represents a potential imaging strategy enabling the identification of high-risk plaques in vivo and holds promise for future clinical implications. PMID:26948523

Pulmonary artery sarcoma with angiosarcoma phenotype mimicking pleomorphic malignant fibrous histiocytoma: a case report

PubMed Central

2012-01-01

Abstract Primary sarcomas of the major blood vessels can be classified based on location in relationship to the wall or by histologic type. Angiosarcomas are malignant neoplasms that arise from the endothelial lining of the blood vessels; those arising in the intimal compartment of pulmonary artery are rare. We report a case of pulmonary artery angiosarcoma in a 36-year old female with pulmonary masses. The patient had no other primary malignant neoplasm, thus excluding a metastatic lesion. Gross examination revealed a thickened right pulmonary artery and a necrotic and hemorrhagic tumor, filling and occluding the vascular lumen. The mass extended distally, within the pulmonary vasculature of the right lung. Microscopically, an intravascular undifferentiated tumor was identified. The tumor cells showed expression for vascular markers VEGFR, VEGFR3, PDGFRa, FGF, Ulex europaeus, FVIII, FLI-1, CD31 and CD34; p53 was overexpressed and Ki67 proliferative rate was increased. Intravascular angiosarcomas are aggressive neoplasms, often associated with poor outcome. Virtual slide The virtual slide(s) for this article can be found here: http://www.diagnosticpathology.diagnomx.eu/vs/2315906377648045. PMID:23134683

Hyperkalemia after irradiation of packed red blood cells: Possible effects with intravascular fetal transfusion

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

Thorp, J.A.; Plapp, F.V.; Cohen, G.R.

1990-08-01

Plasma potassium, calcium, and albumin concentrations in irradiated blood, and in fetal blood before and after transfusion, were measured. Dangerously high plasma potassium levels were observed in some units of irradiated packed red blood cells (range, 13.9 to 66.5 mEq/L; mean, 44.7 mEq/L) and could be one possible explanation for the high incidence of fetal arrhythmia associated with fetal intravascular transfusion. There are many factors operative in the preparation of irradiated packed red blood cells that may predispose to high potassium levels: the age of the red blood cells, the number of procedures used to concentrate the blood, the durationmore » of time elapsed from concentration, the duration of time elapsed from irradiation, and the hematocrit. Use of fresh blood, avoidance of multiple packing procedures, limiting the hematocrit in the donor unit to less than or equal to 80%, and minimizing the time between concentration, irradiation and transfusion may minimize the potassium levels, and therefore making an additional washing procedure unnecessary.« less

Fluid Volume Overload and Congestion in Heart Failure: Time to Reconsider Pathophysiology and How Volume Is Assessed.

PubMed

Miller, Wayne L

2016-08-01

Volume regulation, assessment, and management remain basic issues in patients with heart failure. The discussion presented here is directed at opening a reassessment of the pathophysiology of congestion in congestive heart failure and the methods by which we determine volume overload status. Peer-reviewed historical and contemporary literatures are reviewed. Volume overload and fluid congestion remain primary issues for patients with chronic heart failure. The pathophysiology is complex, and the simple concept of intravascular fluid accumulation is not adequate. The dynamics of interstitial and intravascular fluid compartment interactions and fluid redistribution from venous splanchnic beds to central pulmonary circulation need to be taken into account in strategies of volume management. Clinical bedside evaluations and right heart hemodynamic assessments can alert clinicians of changes in volume status, but only the quantitative measurement of total blood volume can help identify the heterogeneity in plasma volume and red blood cell mass that are features of volume overload in patients with chronic heart failure and help guide individualized, appropriate therapy-not all volume overload is the same. © 2016 American Heart Association, Inc.

Combined targeting of lentiviral vectors and positioning of transduced cells by magnetic nanoparticles.

PubMed

Hofmann, Andreas; Wenzel, Daniela; Becher, Ulrich M; Freitag, Daniel F; Klein, Alexandra M; Eberbeck, Dietmar; Schulte, Maike; Zimmermann, Katrin; Bergemann, Christian; Gleich, Bernhard; Roell, Wilhelm; Weyh, Thomas; Trahms, Lutz; Nickenig, Georg; Fleischmann, Bernd K; Pfeifer, Alexander

2009-01-06

Targeting of viral vectors is a major challenge for in vivo gene delivery, especially after intravascular application. In addition, targeting of the endothelium itself would be of importance for gene-based therapies of vascular disease. Here, we used magnetic nanoparticles (MNPs) to combine cell transduction and positioning in the vascular system under clinically relevant, nonpermissive conditions, including hydrodynamic forces and hypothermia. The use of MNPs enhanced transduction efficiency of endothelial cells and enabled direct endothelial targeting of lentiviral vectors (LVs) by magnetic force, even in perfused vessels. In addition, application of external magnetic fields to mice significantly changed LV/MNP biodistribution in vivo. LV/MNP-transduced cells exhibited superparamagnetic behavior as measured by magnetorelaxometry, and they were efficiently retained by magnetic fields. The magnetic interactions were strong enough to position MNP-containing endothelial cells at the intima of vessels under physiological flow conditions. Importantly, magnetic positioning of MNP-labeled cells was also achieved in vivo in an injury model of the mouse carotid artery. Intravascular gene targeting can be combined with positioning of the transduced cells via nanomagnetic particles, thereby combining gene- and cell-based therapies.

Immunological characterization of pulmonary intravascular macrophages

NASA Technical Reports Server (NTRS)

Chitko-McKown, C. G.; Reddy, D. N.; Chapes, S. K.; McKown, R. D.; Blecha, F.; Spooner, B. S. (Principal Investigator)

1992-01-01

Pulmonary intravascular macrophages (PIMs) are lung macrophages found apposed to the endothelium of pulmonary capillaries. In many species, they are responsible for the clearance of blood-borne particulates and pathogens; however, little else is known about their roles as immunologic effector cells. We compared PIMs with pulmonary alveolar macrophages (PAMs) to determine the relative immunological activities of these two cell populations. Our results suggested that both populations possess similar phagocytic and bactericidal activities. In assays measuring cytotoxicity, PIMs were more cytotoxic than PAMs against virally infected target cells; however, differences between these macrophage populations were not as marked when noninfected targets were used. LPS-stimulated PIMs produced more T-cell proliferative cytokines than PAMs, and both populations of nonstimulated macrophages produced similar amounts of the cytokines. In contrast, PAMs produced more TNF alpha and NO2- than PIMs when both populations were stimulated with LPS; however, nonstimulated PAMs and PIMs produced similar amounts of TNF alpha and NO2. These data suggest that bovine PIMs are immunologically active. Differences between the degrees of activity of PIMs and PAMs indicate that these macrophage populations may have different roles in lung surveillance.

Release of enzymes from cells: transport and distribution within the extracellular space.

PubMed

Mattenheimer, H; Friedel, R

1977-01-01

The distribution in the extracellular space of enzymes released from organ cells was investigated using three models: (1) comparison of enzyme activities in blood plasma and lymph of the ductus thoracicus (dog) and plasma and intestinal lymph (rat); (2) i.v. injection of heterologous, homologous and autologous enzymes in order to increase acutely the activities and to measure the rate constants for the distribution and elimination of the enzymes (rat); or (3) plasmapheresis in order to create an enzyme activity gradient from the interstitial space and to determine the rate constants for the reestablishment of the equilibrium between the extra and intravascular compartments (rat). The results suggest that the enzymes are mainly released into the interstitial fluid and transported via the lymph into the intravascular compartment. From there the enzymes diffuse back into the interstitial compartment and are eliminated by a yet unknown mechanism. Transport of enzymes across the capillary membranes in both directions depends on (1) the permeability of the capillary membranes, which varies from region to region and (2) the molecular seizes of the enzymes.

Micromachined PIN-PMN-PT crystal composite transducer for high-frequency intravascular ultrasound (IVUS) imaging.

PubMed

Li, Xiang; Ma, Teng; Tian, Jian; Han, Pengdi; Zhou, Qifa; Shung, K Kirk

2014-07-01

In this paper, we report the use of micromachined PbIn1/2Nb1/2O3-PbMg1/3Nb2/3O3-PbTiO 3 (PIN-PMNPT) single crystal 1-3 composite material for intravascular ultrasound (IVUS) imaging application. The effective electromechanical coupling coefficient kt(eff) of the composite was measured to be 0.75 to 0.78. Acoustic impedance was estimated to be 20 MRayl. Based on the composite, needle-type and flexible-type IVUS transducers were fabricated. The composite transducer achieved an 86% bandwidth at the center frequency of 41 MHz, which resulted in a 43 μm axial resolution. Ex vivo IVUS imaging was conducted to demonstrate the improvement of axial resolution. The composite transducer was capable of identifying the three layers of a cadaver coronary artery specimen with high resolution. The PIN-PMN-PT-based composite has superior piezoelectric properties comparable to PMN-PT-based composite and its thermal stability is higher than PMN-PT. PIN-PMN-PT crystal can be an alternative approach for fabricating high-frequency composite, instead of using PMN-PT.

Bronchial circulation in the marsupial opossum, Didelphis marsupialis.

PubMed

Bernard, S L; Luchtel, D L; Glenny, R W; Lakshminarayan, S

1996-08-01

This study characterizes the existence of a bronchial circulation in a marsupial, an animal which does not undergo placental development and does not have a ductus arteriosus. Direct perfusion of the lung by the pulmonary vasculature during the fetal development of opossums may occur, potentially eliminating the need for a bronchial circulation. We used radio- and fluorescent-labeled microspheres in conjunction with postmortem intravascular casting to determine if opossums have a systemic (bronchial) blood supply to the lung (n = 9). Gross postmortem examination of the intravascular casts showed a well-developed common bronchial artery. The histological distribution pattern of fluorescent microspheres was primarily to the airways. A few fluorescent microspheres were observed in the alveolar capillaries, indicating that a precapillary bronchial-to-pulmonary anastomosis exists in the opossum. Using the reference flow technique, total bronchial blood flow to the left lung averaged 0.95 +/- 0.58 SE ml/min. The presence of a bronchial circulation in the opossum suggests that it is more than a vestigial structure from embryonic development, potentially supporting its functional importance for carrying nutrients to the airway.

Investigation of cyano-bridged coordination nanoparticles Gd3+/[Fe(CN)6]3-/d-mannitol as T1-weighted MRI contrast agents

NASA Astrophysics Data System (ADS)

Perrier, M.; Gallud, A.; Ayadi, A.; Kennouche, S.; Porredon, C.; Gary-Bobo, M.; Larionova, J.; Goze-Bac, Ch.; Zanca, M.; Garcia, M.; Basile, I.; Long, J.; de Lapuente, J.; Borras, M.; Guari, Y.

2015-07-01

Cyano-bridged Gd3+/[Fe(CN)6]3- coordination polymer nanoparticles of 3-4 nm stabilized with d-mannitol presenting a high r1 relaxivity value of 11.4 mM-1 s-1 were investigated in vivo as contrast agents (CA) for Magnetic Resonance Imaging (MRI). They allow an increase of the MR image contrast and can act as an efficient intravascular T1 CA with a relatively long blood-circulation lifetime (60 min) without specific toxicity.Cyano-bridged Gd3+/[Fe(CN)6]3- coordination polymer nanoparticles of 3-4 nm stabilized with d-mannitol presenting a high r1 relaxivity value of 11.4 mM-1 s-1 were investigated in vivo as contrast agents (CA) for Magnetic Resonance Imaging (MRI). They allow an increase of the MR image contrast and can act as an efficient intravascular T1 CA with a relatively long blood-circulation lifetime (60 min) without specific toxicity. Electronic supplementary information (ESI) available: Experimental details and procedures, toxicological data, physical characterization. See DOI: 10.1039/c5nr01557j

Left main coronary artery stenosis: severity evaluation and implications for management.

PubMed

Habibi, Susan E; Shah, Rahman; Berzingi, Chalak O; Melchior, Ryan; Sumption, Kevin F; Jovin, Ion S

2017-03-01

The significant stenosis of the left main coronary artery is associated with poor outcomes and is considered a strong indication for revascularization. However, deciding whether the stenosis is significant can sometimes be challenging, especially when the degree of stenosis is intermediate, and can necessitate additional tests and imaging modalities. Areas covered: We did a literature search using keywords like 'left main', 'imaging', 'intravascular ultrasound', 'fractional flow reserve', 'computed tomographic angiography' and 'magnetic resonance imaging'. The most commonly used methods for better characterizing intermediate left main coronary stenoses are intravascular ultrasound and fractional flow reserve, while optical coherence tomography is the newer technique that provides better images, but for which not as much data is available. The noninvasive techniques are coronary computed tomographic angiography and, to a lesser degree, coronary magnetic resonance imaging. Expert commentary: Accurately determining the severity of left main coronary stenosis can mean the difference between a major intervention and conservative therapy. The reviewed newer imaging modalities give us greater confidence that patients with left main stenosis are assigned to the right treatment modality.

Distribution of anti-CD68 (EBM11) immunoreactivity in formalin-fixed, paraffin-embedded bovine tissues.

PubMed

Ackermann, M R; DeBey, B M; Stabel, T J; Gold, J H; Register, K B; Meehan, J T

1994-05-01

A commercially acquired anti-human macrophage antibody (anti-CD68; EBM11) was used in an immunocytochemical technique to detect macrophages in formalin-fixed, paraffin-embedded tissues from cattle, pigs, humans, rats, turkeys, dogs, and cats. In healthy cattle, the antibody labeled alveolar macrophages, pulmonary intravascular cells (presumably intravascular macrophages), and macrophage-like cells in other tissues. In bovine lungs infected with Pasteurella haemolytica, EBM11 antibody labeled 95% of alveolar macrophages and macrophages within alveolar septa but only 0-2% of streaming or "oat" leukocytes. Alveolar macrophages were also stained by EBM11 in pigs but not in rats, turkeys, dogs, and cats. The antibody also stained macrophage aggregates in the mesenteric lymph nodes and intestinal lamina propria of Mycobacterium paratuberculosis-infected cattle. This study shows that the anti-CD68 (EBM11) antibody is a useful marker of macrophages in normal bovine tissues or tissues from areas of acute or chronic inflammation that have been routinely processed. The study also adds strength to the growing evidence suggesting that streaming leukocytes seen in pneumonic pasteurellosis are neutrophils.

Does bipolar electrocoagulation time affect vessel weld strength?

PubMed Central

Harrison, J D; Morris, D L

1991-01-01

The value of the bipolar electrocoagulator in the haemostasis of bleeding ulcers is controversial. We have therefore investigated the effect of different coagulation times on vessel weld strength achieved by the bipolar device. Welds were then made in vessels of known diameter using a standard 10F endoscopic haemostatic probe at coagulation times of two and 20 seconds. The intravascular temperature achieved at each time was measured. Vessel weld strength achieved by bipolar electrocoagulation was much greater at 20 seconds (approximately twice that at two seconds) and was highly significantly greater at all vessel diameters. There was a gradual reduction in weld strength with increasing vessel diameter, an effect that was seen for both two and 20 seconds of electrocoagulation. Intravascular temperature was significantly higher at 20 seconds than at two seconds. We conclude that vessel weld strength is related to coagulation time and that any future studies comparing the bipolar electrocoagulator with other haemostatic devices should use longer periods of bipolar electrocoagulation and record the coagulation time in order to optimise the clinical value of the device. PMID:1864540

Mannose-binding lectin and its associated proteases (MASPs) mediate coagulation and its deficiency is a risk factor in developing complications from infection, including disseminated intravascular coagulation

PubMed Central

Takahashi, Kazue; Chang, Wei-Chuan; Takahashi, Minoru; Pavlov, Vasile; Ishida, Yumi; La Bonte, Laura; Shi, Lei; Fujita, Teizo; Stahl, Gregory L.; Van Cott, Elizabeth M.

2010-01-01

The first line of host defense is the innate immune system that includes coagulation factors and pattern recognition molecules, one of which is mannose-binding lectin (MBL). Previous studies have demonstrated that MBL deficiency increases susceptibility to infection. Several mechanisms are associated with increased susceptibility to infection, including reduced opsonophagocytic killing and reduced lectin complement pathway activation. In this study, we demonstrate that MBL and MBL-associated serine protease (MASP)-1/3 together mediate coagulation factor-like activities, including thrombin-like activity. MBL and/or MASP-1/3 deficient hosts demonstrate in vivo evidence that MBL and MASP-1/3 are involved with hemostasis following injury. Staphylococcus aureus infected MBL null mice developed disseminated intravascular coagulation (DIC), which was associated with elevated blood IL-6 levels (but not TNF-α and multi-organ inflammatory responses). Infected MBL null mice also develop liver injury. These findings suggest that MBL deficiency may manifest into DIC and organ failure during infectious diseases. PMID:20399528

Visible light optical coherence microscopy imaging of the mouse cortex with femtoliter volume resolution

NASA Astrophysics Data System (ADS)

Merkle, Conrad W.; Chong, Shau Poh; Kho, Aaron M.; Zhu, Jun; Kholiqov, Oybek; Dubra, Alfredo; Srinivasan, Vivek J.

2018-02-01

Most flying-spot Optical Coherence Tomography (OCT) and Optical Coherence Microscopy (OCM) systems use a symmetric confocal geometry, where the detection path retraces the illumination path starting from and ending with the spatial mode of a single mode optical fiber. Here, we describe a visible light OCM instrument that breaks this symmetry to improve transverse resolution without sacrificing collection efficiency in scattering tissue. This was achieved by overfilling a 0.3 numerical aperture (NA) water immersion objective on the illumination path, while maintaining a conventional Gaussian mode detection path (1/e2 intensity diameter 0.82 Airy disks), enabling 1.1 μm full-width at half-maximum (FWHM) transverse resolution. At the same time, a 0.9 μm FWHM axial resolution in tissue, achieved by a broadband visible light source, enabled femtoliter volume resolution. We characterized this instrument according to paraxial coherent microscopy theory, and then used it to image the meningeal layers, intravascular red blood cell-free layer, and myelinated axons in the mouse neocortex in vivo through the thinned skull. Finally, by introducing a 0.8 NA water immersion objective, we improved the lateral resolution to 0.44 μm FWHM, which provided a volumetric resolution of 0.2 fL, revealing cell bodies in cortical layer I of the mouse brain with OCM for the first time.

Bacteremic complications of intravascular catheter tip colonization with Gram-negative micro-organisms in patients without preceding bacteremia.

PubMed

van Eck van der Sluijs, A; Oosterheert, J J; Ekkelenkamp, M B; Hoepelman, I M; Peters, Edgar J G

2012-06-01

Although Gram-negative micro-organisms are frequently associated with catheter-related bloodstream infections, the prognostic value and clinical implication of a positive catheter tip culture with Gram-negative micro-organisms without preceding bacteremia remains unclear. We determined the outcomes of patients with intravascular catheters colonized with these micro-organisms, without preceding positive blood cultures, and identified risk factors for the development of subsequent Gram-negative bacteremia. All patients with positive intravascular catheter tip cultures with Gram-negative micro-organisms at the University Medical Center, Utrecht, The Netherlands, between 2005 and 2009, were retrospectively studied. Patients with Gram-negative bacteremia within 48 h before catheter removal were excluded. The main outcome measure was bacteremia with Gram-negative micro-organisms. Other endpoints were length of the hospital stay, in-hospital mortality, secondary complications of Gram-negative bacteremia, and duration of intensive care admission. A total of 280 catheters from 248 patients were colonized with Gram-negative micro-organisms. Sixty-seven cases were excluded because of preceding positive blood cultures, leaving 213 catheter tips from 181 patients for analysis. In 40 (19%) cases, subsequent Gram-negative bacteremia developed. In multivariate analysis, arterial catheters were independently associated with subsequent Gram-negative bacteremia (odds ratio [OR] = 5.00, 95% confidence interval [CI]: 1.20-20.92), as was selective decontamination of the digestive tract (SDD) (OR = 2.47, 95% CI: 1.07-5.69). Gram-negative bacteremia in patients who received SDD was predominantly caused by cefotaxime (part of the SDD)-resistant organisms. Mortality was significantly higher in the group with subsequent Gram-negative bacteremia (35% versus 20%, OR = 2.12, 95% CI: 1.00-4.49). Patients with a catheter tip colonized with Gram-negative micro-organisms had a high chance of subsequent Gram-negative bacteremia from any cause. This may be clinically relevant, as starting antibiotic treatment pre-emptively in high-risk patients with Gram-negative micro-organisms cultured from arterial intravenous catheters may be beneficial.

Video networking of cardiac catheterization laboratories.

PubMed

Tobis, J; Aharonian, V; Mansukhani, P; Kasaoka, S; Jhandyala, R; Son, R; Browning, R; Youngblood, L; Thompson, M

1999-02-01

The purpose of this study was to assess the feasibility and accuracy of a video telecommunication network to transmit coronary images to provide on-line interaction between personnel in a cardiac catheterization laboratory and a remote core laboratory. A telecommunication system was installed in the cardiac catheterization laboratory at Kaiser Hospital, Los Angeles, and the core laboratory at the University of California, Irvine, approximately 40 miles away. Cineangiograms, live fluoroscopy, intravascular ultrasound studies and images of the catheterization laboratory were transmitted in real time over a dedicated T1 line at 768 kilobytes/second at 15 frames/second. These cases were performed during a clinical study of angiographic guidance versus intravascular ultrasound (IVUS) guidance of stent deployment. During the cases the core laboratory performed quantitative analysis of the angiograms and ultrasound images. Selected images were then annotated and transmitted back to the catheterization laboratory to facilitate discussion during the procedure. A successful communication hookup was obtained in 39 (98%) of 40 cases. Measurements of angiographic parameters were very close between the original cinefilm and the transmitted images. Quantitative analysis of the ultrasound images showed no significant difference in any of the diameter or cross-sectional area measurements between the original ultrasound tape and the transmitted images. The telecommunication link during the interventional procedures had a significant impact in 23 (58%) of 40 cases affecting the area to be treated, the size of the inflation balloon, recognition of stent underdeployment, or the existence of disease in other areas that was not noted on the original studies. Current video telecommunication systems provide high-quality images on-line with accurate representation of cineangiograms and intravascular ultrasound images. This system had a significant impact on 58% of the cases in this small clinical trial. Telecommunication networks between hospitals and a central core laboratory may facilitate physician training and improve technical skills and judgement during interventional procedures. This project has implications for how multicenter clinical trials could be operated through telecommunication networks to ensure conformity with the protocol.

Hypoglycemic depression of hepatic phagocytosis in vivo and in the in situ perfused rat liver.

PubMed

Kober, P M; Filkins, J P

1981-01-01

Depression of the phagocytic function of the reticuloendothelial system (RES) during endotoxic hypoglycemia has been implicated in the pathogenesis of endotoxin shock. The present study evaluated the in vivo effects of hypoglycemia on RES function and assessed the effects of an vivo bout of hypoglycemia on phagocytosis in the in situ perfused rat liver. Hypoglycemia was produced in male Holtzman rats using either 1 U of regular insulin (RI) (ILETIN, Lilly) or 0.75 U of long-acting insulin (LAI) (85% LENTE/15% ULTRALENTE, Lilly). RES function was quantitated by intravascular clearance of 8 mg/100 gm body weight colloidal carbon (CC). Two hr after RI and 2.5 hr after LAI, the intravascular halftimes of CC clearance were 19 +/- 2 min (N = 22) and 18 +/- 1 min (N = 19), respectively, as compared to control, 11.3 +/- 0.4 min (N = 53, P less than 0.001). The corresponding plasma glucose (PG) levels were 95 +/- 2 mg/dl in control, 14.4 +/- 0.9 for the RI group, and 17 +/- 1 for LAI. Two hr after RI, livers were perfused for 10 min in situ with 50 mg/liter CC in saline 5% rat serum. PG for control liver donors were 90 +/- 3 mg/dl, while those for hypoglycemic liver donors were 15 +/- 2. CC uptake was decreased from 22 micrograms/min/gm liver in the control (+ serum, n = 19) to 11 +/- 2 in hypoglycemia livers (N = 6); no effect of serum on hypoglycemic depression of the RES was seen. There were no differences in flow rates in the 2 groups. These results indicate that hypoglycemia directly impairs RES function and that the in vivo depression of intravascular clearance is not related to either the presence or absence of serum factors or total hepatic blood flow. Thus, the characteristic hypoglycemia of endotoxin shock may contribute to RES depression and the lethal shock syndrome.

Temperature Profiles of Different Cooling Methods in Porcine Pancreas Procurement

PubMed Central

Weegman, Brad P.; Suszynski, Thomas M.; Scott, William E.; Ferrer, Joana; Avgoustiniatos, Efstathios S.; Anazawa, Takayuki; O’Brien, Timothy D.; Rizzari, Michael D.; Karatzas, Theodore; Jie, Tun; Sutherland, David ER.; Hering, Bernhard J.; Papas, Klearchos K.

2014-01-01

Background Porcine islet xenotransplantation is a promising alternative to human islet allotransplantation. Porcine pancreas cooling needs to be optimized to reduce the warm ischemia time (WIT) following donation after cardiac death, which is associated with poorer islet isolation outcomes. Methods This study examines the effect of 4 different cooling Methods on core porcine pancreas temperature (n=24) and histopathology (n=16). All Methods involved surface cooling with crushed ice and chilled irrigation. Method A, which is the standard for porcine pancreas procurement, used only surface cooling. Method B involved an intravascular flush with cold solution through the pancreas arterial system. Method C involved an intraductal infusion with cold solution through the major pancreatic duct, and Method D combined all 3 cooling Methods. Results Surface cooling alone (Method A) gradually decreased core pancreas temperature to < 10 °C after 30 minutes. Using an intravascular flush (Method B) improved cooling during the entire duration of procurement, but incorporating an intraductal infusion (Method C) rapidly reduced core temperature 15–20 °C within the first 2 minutes of cooling. Combining all methods (Method D) was the most effective at rapidly reducing temperature and providing sustained cooling throughout the duration of procurement, although the recorded WIT was not different between Methods (p=0.36). Histological scores were different between the cooling Methods (p=0.02) and the worst with Method A. There were differences in histological scores between Methods A and C (p=0.02) and Methods A and D (p=0.02), but not between Methods C and D (p=0.95), which may highlight the importance of early cooling using an intraductal infusion. Conclusions In conclusion, surface cooling alone cannot rapidly cool large (porcine or human) pancreata. Additional cooling with an intravascular flush and intraductal infusion results in improved core porcine pancreas temperature profiles during procurement and histopathology scores. These data may also have implications on human pancreas procurement since use of an intraductal infusion is not common practice. PMID:25040217

Nitric Oxide-Dependent Endothelial Dysfunction and Reduced Arginine Bioavailability in Plasmodium vivax Malaria but No Greater Increase in Intravascular Hemolysis in Severe Disease.

PubMed

Barber, Bridget E; William, Timothy; Grigg, Matthew J; Piera, Kim A; Chen, Youwei; Wang, Hao; Weinberg, J Brice; Yeo, Tsin W; Anstey, Nicholas M

2016-11-15

 Pathogenesis of severe Plasmodium vivax malaria is poorly understood. Endothelial dysfunction and reduced nitric oxide (NO) bioavailability characterize severe falciparum malaria, but have not been assessed in severe vivax malaria.  In patients with severe vivax malaria (n = 9), patients with nonsevere vivax malaria (n = 58), and healthy controls (n = 79), we measured NO-dependent endothelial function by using reactive hyperemia-peripheral arterial tonometry (RH-PAT) and assessed associations with arginine, asymmetric dimethylarginine (ADMA), and hemolysis.  The L-arginine level and the L-arginine to ADMA ratio (a measure of L-arginine bioavailability) were reduced in patients with severe vivax malaria and those with nonsevere vivax malaria, compared with healthy controls (median L-arginine level, 65, 66, and 98 µmol/mL, respectively [P = .0001]; median L-arginine to ADMA ratio, 115, 125, and 187, respectively [P = .0001]). Endothelial function was impaired in proportion to disease severity (median RH-PAT index, 1.49, 1.73, and 1.97 in patients with severe vivax malaria, those with nonsevere vivax malaria, and healthy controls, respectively; P = .018) and was associated with the L-arginine to ADMA ratio. While the posttreatment fall in hemoglobin level was greater in severe vivax malaria as compared to nonsevere vivax malaria (2.5 vs 1 g/dL; P = .0001), markers of intravascular hemolysis were not higher in severe disease.  Endothelial function is impaired in nonsevere and severe vivax malaria, is associated with reduced L-arginine bioavailability, and may contribute to microvascular pathogenesis. Severe disease appears to be more associated with extravascular hemolysis than with intravascular hemolysis. © The Author 2016. Published by Oxford University Press for the Infectious Diseases Society of America. All rights reserved. For permissions, e-mail journals.permissions@oup.com.

Intravascular hemolysis induced by phospholipases A2 from the venom of the Eastern coral snake, Micrurus fulvius: Functional profiles of hemolytic and non-hemolytic isoforms.

PubMed

Fernández, María Laura; Quartino, Pablo Yunes; Arce-Bejarano, Ruth; Fernández, Julián; Camacho, Luis F; Gutiérrez, José María; Kuemmel, Daniel; Fidelio, Gerardo; Lomonte, Bruno

2018-04-01

A unique feature of the venom of Micrurus fulvius (Eastern coral snake) is its ability to induce severe intravascular hemolysis in particular species, such as dogs or mice. This effect was previously shown to be induced by distinct phospholipase A 2 (PLA 2 ) isoforms which cause direct hemolysis in vitro, an uncommon finding for such enzymes. The functional profiles of PLA 2 -17, a direct hemolytic enzyme, and PLA 2 -12, a co-existing venom isoform lacking such effect, were compared. The enzymes differed not only in their ability to cause intravascular hemolysis: PLA 2 -17 additionally displayed lethal, myotoxic, and anticoagulant actions, whereas PLA 2 -12 lacked these effects. PLA 2 -12 was much more active in hydrolyzing a monodisperse synthetic substrate than PLA 2 -17, but the catalytic activity of latter was notably higher on a micellar substrate, or towards pure phospholipid artificial monolayers under controlled lateral pressures. Interestingly, PLA 2 -17 could hydrolyze substrate at a pressure of 20 mN m -1 , in contrast to PLA 2 -12 or the non-toxic pancreatic PLA 2 . This suggests important differences in the monolayer penetrating power, which could be related to differences in toxicity. Comparative examination of primary structures and predicted three-dimensional folding of PLA 2 -12 and PLA 2 -17, revealed that differences concentrate in their N-terminal and central regions, leading to variations of the surface properties at the membrane interacting interface. PLA 2 -17 presents a less basic interfacial surface than PLA 2 -12, but more bulky aromatic residues, which could be associated to its higher membrane-penetrating strength. Altogether, these structural and functional comparative observations suggest that the ability of PLA 2 s to penetrate substrate interfaces could be a major determinant of toxicity, perhaps more important than protein surface charge. Copyright © 2017 Elsevier B.V. All rights reserved.

Absence of accelerated atherosclerotic disease progression after intracoronary infusion of bone marrow derived mononuclear cells in patients with acute myocardial infarction--angiographic and intravascular ultrasound--results from the TErapia Celular Aplicada al Miocardio Pilot study.

PubMed

Arnold, Roman; Villa, Adolfo; Gutiérrez, Hipólito; Sánchez, Pedro L; Gimeno, Federico; Fernández, Maria E; Gutiérrez, Oliver; Mota, Pedro; Sánchez, Ana; García-Frade, Javier; Fernández-Avilés, Francisco; San Román, Jose A

2010-06-01

We tried to evaluate a putative negative effect on coronary atherosclerosis in patients receiving intracoronary infusion of unfractionated bone marrow mononuclear cells (BMMC) following an acute ST-elevation myocardial infarction. Peripheral blood mononuclear cells or enriched CD133(+) BMMC have been associated with accelerated atherosclerosis of the distal segment of the infarct related artery (IRA). Thirty-seven patients with ST-elevation myocardial infarction from the TECAM pilot study underwent intracoronary infusion of autologous BMMC 9 +/- 3.1 days after onset of symptoms. We compared angiographic changes from baseline to 9 months of follow-up in the distal non-stented segment of the IRA, as well as in the contralateral coronary artery, with a matched control group. A subgroup of 15 treated patients underwent additional IVUS within the distal segment of the IRA. No difference between stem cell and control group were found regarding changes in minimum lumen diameter (0.006 +/- 0.42 vs 0.06 +/- 0.41 mm, P = ns) and the percentage of stenosis (-2.68 +/- 12.33% vs -1.78 +/- 8.75%, P = ns) at follow-up. Likewise, no differences were seen regarding changes in the contralateral artery (minimum lumen diameter -0.004 +/- 0.54 mm vs -0.06 +/- 0.35 mm, P = ns). In the intravascular ultrasound substudy, no changes were demonstrated comparing baseline versus follow-up in maximum area stenosis and plaque volume. In this pilot study, analysis of a subgroup of patients found that intracoronary injection of unfractionated BMMC in patients with acute ST-elevation myocardial infarction was not associated with accelerated atherosclerosis progression at mid term. Prospective, randomised studies in large cohorts with long-term angiographic and intravascular ultrasound follow-up are necessary to determine the safety of this therapy. Copyright 2010 Mosby, Inc. All rights reserved.

Multislice spiral computed tomography for the evaluation of stent patency after left main coronary artery stenting: a comparison with conventional coronary angiography and intravascular ultrasound.

PubMed

Van Mieghem, Carlos A G; Cademartiri, Filippo; Mollet, Nico R; Malagutti, Patrizia; Valgimigli, Marco; Meijboom, Willem B; Pugliese, Francesca; McFadden, Eugene P; Ligthart, Jurgen; Runza, Giuseppe; Bruining, Nico; Smits, Pieter C; Regar, Evelyn; van der Giessen, Willem J; Sianos, Georgios; van Domburg, Ron; de Jaegere, Peter; Krestin, Gabriel P; Serruys, Patrick W; de Feyter, Pim J

2006-08-15

Surveillance conventional coronary angiography (CCA) is recommended 2 to 6 months after stent-supported left main coronary artery (LMCA) percutaneous coronary intervention due to the unpredictable occurrence of in-stent restenosis (ISR), with its attendant risks. Multislice computed tomography (MSCT) is a promising technique for noninvasive coronary evaluation. We evaluated the diagnostic performance of high-resolution MSCT to detect ISR after stenting of the LMCA. Seventy-four patients were prospectively identified from a consecutive patient population scheduled for follow-up CCA after LMCA stenting and underwent MSCT before CCA. Until August 2004, a 16-slice scanner was used (n = 27), but we switched to the 64-slice scanner after that period (n = 43). Patients with initial heart rates > 65 bpm received beta-blockers, which resulted in a mean periscan heart rate of 57 +/- 7 bpm. Among patients with technically adequate scans (n = 70), MSCT correctly identified all patients with ISR (10 of 70) but misclassified 5 patients without ISR (false-positives). Overall, the accuracy of MSCT for detection of angiographic ISR was 93%. The sensitivity, specificity, and positive and negative predictive values were 100%, 91%, 67%, and 100%, respectively. When analysis was restricted to patients with stenting of the LMCA with or without extension into a single major side branch, accuracy was 98%. When both branches of the LMCA bifurcation were stented, accuracy was 83%. For the assessment of stent diameter and area, MSCT showed good correlation with intravascular ultrasound (r = 0.78 and 0.73, respectively). An intravascular ultrasound threshold value > or = 1 mm was identified to reliably detect in-stent neointima hyperplasia with MSCT. Current MSCT technology, in combination with optimal heart rate control, allows reliable noninvasive evaluation of selected patients after LMCA stenting. MSCT is safe to exclude left main ISR and may therefore be an acceptable first-line alternative to CCA.

Relation between intravascular electrolyte level and course of parturition in dairy cows.

PubMed

Seyrek-Intas, K; Seyrek-Intas, D; Failing, K; Yilmazbas Mecitoglu, G; Bostedt, H

2013-01-01

To determine the intravascular electrolyte status in dairy cows with respect to age and different courses of parturition to clarify etiological factors influencing peri- or intrapartal imbalances of electrolyte homeostasis. A total of 64 cows at birth were evaluated (primiparous n = 34, pluriparous n = 30). Thirty-three cows showed normal delivery, while 31 cows had a complicated birth. Blood samples were collected intra partum (i. p.) and 2, 4, 6, 8, 12, 16, 24 h post partum (p. p.) as well as [2, 3, 4, 5, 7, 10 days p. p. and levels of total calcium (Catotal), ionized calcium (Caion), inorganic phosphate (Pa), Mg, Na, K, Cl were determined. The results revealed that electrolytes show great fluctuation during and immediately p. p. in relation to age. Already during parturition pluriparous cows had a lower Catotal and Pa concentration compared to primiparous animals. Cows with dystocia exhibited a more intensive and longer lasting decrease of Ca compared to cows with normal birth. In relation to age and severity of birth Pa concentration showed a differing but basically typical course for this electrolyte. Mg, Na, K and Cl concentrations were higher during and immediately after birth compared to p. p. values. Until day 10 p. p. these electrolyte concentrations declined more in older cows with dystocia compared to younger animals. However, the influence of dystocia on concentration of these electrolytes was milder in contrast to Ca and Pa. In summary, primarily older cows are predisposed to imbalances of electrolyte homeostasis intra partum and at the beginning of the lactation. These changes are potentiated in case of complications during parturition. Intravascular Catotal, Caion as well as Pa are most severely affected. These results may constitute the basis for a comprehensive metaphylaxis during the peripartal period, especially in cows after dystocia, to positively influence the early convalescence phase.

Intravascular probe for detection of vulnerable plaque

NASA Astrophysics Data System (ADS)

Patt, Bradley E.; Iwanczyk, Jan S.; MacDonald, Lawrence R.; Yamaguchi, Yuko; Tull, Carolyn R.; Janecek, Martin; Hoffman, Edward J.; Strauss, H. William; Tsugita, Ross; Ghazarossian, Vartan

2001-12-01

Coronary angiography is unable to define the status of the atheroma, and only measures the luminal dimensions of the blood vessel, without providing information about plaque content. Up to 70% of heart attacks are caused by minimally obstructive vulnerable plaques, which are too small to be detected adequately by angiography. We have developed an intravascular imaging detector to identify vulnerable coronary artery plaques. The detector works by sensing beta or conversion electron radiotracer emissions from plaque-binding radiotracers. The device overcomes the technical constraints of size, sensitivity and conformance to the intravascular environment. The detector at the distal end of the catheter uses six 7mm long by 0.5mm diameter scintillation fibers coupled to 1.5m long plastic fibers. The fibers are offset from each other longitudinally by 6mm and arranged spirally around a guide wire in the catheter. At the proximal end of the catheter the optical fibers are coupled to an interface box with a snap on connector. The interface box contains a position sensitive photomultiplier tube (PSPMT) to decode the individual fibers. The whole detector assembly fits into an 8-French (2.7 mm in diameter) catheter. The PSPMT image is further decoded with software to give a linear image, the total instantaneous count rate and an audio output whose tone corresponds to the count rate. The device was tested with F-18 and Tl-204 sources. Spectrometric response, spatial resolution, sensitivity and beta to background ratio were measured. System resolution is 6 mm and the sensitivity is >500 cps / micrometers Ci when the source is 1 mm from the detector. The beta to background ratio was 11.2 for F-18 measured on a single fiber. The current device will lead to a system allowing imaging of labeled vulnerable plaque in coronary arteries. This type of signature is expected to enable targeted and cost effective therapies to prevent acute coronary artery diseases such as: unstable angina, acute myocardial infarction, and sudden cardiac death.

Prevalence, Features, and Prognostic Importance of Edge Dissection After Drug-Eluting Stent Implantation: An ADAPT-DES Intravascular Ultrasound Substudy.

PubMed

Kobayashi, Nobuaki; Mintz, Gary S; Witzenbichler, Bernhard; Metzger, D Christopher; Rinaldi, Michael J; Duffy, Peter L; Weisz, Giora; Stuckey, Thomas D; Brodie, Bruce R; Parvataneni, Rupa; Kirtane, Ajay J; Stone, Gregg W; Maehara, Akiko

2016-07-01

Intravascular ultrasound detects stent edge dissections after percutaneous coronary intervention that are not seen angiographically. This study investigated the association between stent edge dissections and clinical outcomes. ADAPT-DES (Assessment of Dual Antiplatelet Therapy With Drug-Eluting Stents) was a large-scale, prospective, multicenter study of patients undergoing drug-eluting stent implantation. In this prospective substudy, 2062 patients (2433 lesions) were evaluated with intravascular ultrasound to characterize the morphological features and clinical outcomes of stent edge dissection after percutaneous coronary intervention. The prevalence of post-percutaneous coronary intervention stent edge dissection was 6.6% per lesion (161 of 2433). Calcified plaque at the proximal stent edge (relative risk [RR]=1.72; P=0.04) and proximal stent edge expansion (RR=1.18; P=0.004) were predictors for proximal dissection; attenuated plaque at the distal stent edge (RR=3.52; P=0.004), distal reference plaque burden (RR=1.56; P<0.0001), and distal edge stent expansion (RR=1.11; P=0.02) were predictors for distal dissection. At 1-year follow-up, target lesion revascularization was more common in lesions with versus without dissection (5.2% versus 2.7%; P=0.04). Multivariable analysis indicated that residual dissection was associated with target lesion revascularization at 1-year follow-up (RR=2.67; P=0.02). Among lesions with dissection, smaller effective lumen area increased the risk of target lesion revascularization at 1-year follow-up (cutoff value of 5.1 mm(2); P=0.05). Greater stent expansion and the presence of large, calcified, and/or attenuated plaques were independent predictors of stent edge dissection. Residual stent edge dissection, especially with a smaller effective lumen area, was associated with target lesion revascularization during 1-year follow-up after drug-eluting stent implantation. URL: http://www.clinicaltrials.gov. Unique identifier: NCT00638794. © 2016 American Heart Association, Inc.

Pathologic Intimal Thickening Plaque Phenotype: Not as Innocent as Previously Thought. A Serial 3D Intravascular Ultrasound Virtual Histology Study.

PubMed

Kovarnik, Tomas; Chen, Zhi; Wahle, Andreas; Zhang, Ling; Skalicka, Hana; Kral, Ales; Lopez, John J; Horak, Jan; Sonka, Milan; Linhart, Ales

2017-01-01

Pathologic intimal thickening (PIT) has been considered a benign plaque phenotype. We report plaque phenotypic changes in a baseline/follow-up intravascular ultrasound-based virtual histology study. A total of 61 patients with stable coronary artery disease were analyzed from the HEAVEN trial (89 patients randomized between routine statin therapy vs atorvastatin 80mg and ezetimibe 10mg) with serial intravascular ultrasound imaging of nonculprit vessels. We compared changes in 693 baseline and follow-up 5-mm long segments in a novel risk score, Liverpool Active Plaque Score (LAPS), plaque parameters, and plaque composition. The PIT showed the highest increase of risk score and, with fibrous plaque, also the LAPS. Necrotic core (NC) abutting to the lumen increased in PIT (22 ± 51.7; P = .0001) and in fibrous plaque (17.9 ± 42.6; P = .004) but decreased in thin cap fibroatheroma (TCFA) (⿿15.14 ± 52.2; P = .001). The PIT was the most likely of all nonthin cap fibroatheroma plaque types to transform into TCFA at follow-up (11% of all TCFA found during follow-up and 35.9% of newly-developed TCFA), but showed (together with fibrous plaque) the lowest stability during lipid-lowering therapy (24.7% of PIT remained PIT and 24.5% of fibrous plaque remained fibrous plaque). Over the 1-year follow-up, PIT was the most dynamic of the plaque phenotypes and was associated with an increase of risk score and LAPS (together with fibrous plaque), NC percentage (together with fibrous plaque) and NC abutting to the lumen, despite a small reduction of plaque volume during lipid-lowering therapy. The PIT was the main source for new TCFA segments. Copyright © 2016 Sociedad Española de Cardiología. Published by Elsevier España, S.L.U. All rights reserved.

True identity of endocapillary proliferation: a case of intravascular large B cell lymphoma diagnosed with immunohistochemical study of kidney biopsy and literature review.

PubMed

Iwagami, Masao; Furuya, Rei; Tsutsumi, Daimu; Mochida, Yasuhiro; Ishioka, Kunihiro; Oka, Machiko; Maesato, Kyoko; Moriya, Hidekazu; Ohtake, Takayasu; Hidaka, Sumi; Kobayashi, Shuzo

2012-11-01

A 78-year-old Japanese female presented with low-grade fever, malaise, and appetite loss lasting for 1 month. Upper and lower gastrointestinal endoscopy and contrast-enhanced whole-body computed tomography (CT) revealed no abnormal findings at a referring hospital. She was referred to our hospital because of bilateral leg edema and 2.5 g/day proteinuria. Serum creatinine was 0.73 mg/dl and the kidneys were not enlarged. Kidney biopsy showed marked endocapillary proliferation with mesangiolysis. Soon after the kidney biopsy, her symptoms improved spontaneously, along with decreases in lactate dehydrogenase (LDH) from 503 to 197 IU/l, C-reactive protein (CRP) from 4.47 to 0.66 mg/dl, and soluble interleukin-2 receptor (sIL-2R) from 1789 to 1001 U/ml. Thus, she was followed carefully as an outpatient. One month later, however, she presented with dysarthria and right-sided hemiparesis, and diffusion-weighted brain magnetic resonance imaging (MRI) showed multiple high-intensity areas. She also had respiratory failure, and lung perfusion scintigraphy showed multiple low blood stream areas. Suspecting some endovascular abnormality, we performed immunohistochemical staining of the kidney biopsy specimen taken previously to find that endocapillary infiltrating cells were CD20-positive B lymphocytes. The infiltrating cells were confined to the endocapillary compartment in glomeruli and peritubular capillaries. Both clinical and pathological findings led us to diagnose intravascular large B cell lymphoma (IVLBCL). Two bone marrow biopsies and random skin biopsies were performed, but no abnormality was found. The present case demonstrates that clinical course and renal biopsy findings of intravascular large B cell lymphoma may mimic other renal conditions and that the identification of cell types with immunohistochemical staining may help establish an accurate diagnosis.

Combined chirp coded tissue harmonic and fundamental ultrasound imaging for intravascular ultrasound: 20–60 MHz phantom and ex vivo results

PubMed Central

Park, Jinhyoung; Li, Xiang; Zhou, Qifa; Shung, K. Kirk

2013-01-01

The application of chirp coded excitation to pulse inversion tissue harmonic imaging can increase signal to noise ratio. On the other hand, the elevation of range side lobe level, caused by leakages of the fundamental signal, has been problematic in mechanical scanners which are still the most prevalent in high frequency intravascular ultrasound imaging. Fundamental chirp coded excitation imaging can achieve range side lobe levels lower than –60 dB with Hanning window, but it yields higher side lobes level than pulse inversion chirp coded tissue harmonic imaging (PI-CTHI). Therefore, in this paper a combined pulse inversion chirp coded tissue harmonic and fundamental imaging mode (CPI-CTHI) is proposed to retain the advantages of both chirp coded harmonic and fundamental imaging modes by demonstrating 20–60 MHz phantom and ex vivo results. A simulation study shows that the range side lobe level of CPI-CTHI is 16 dB lower than PI-CTHI, assuming that the transducer translates incident positions by 50 μm when two beamlines of pulse inversion pair are acquired. CPI-CTHI is implemented for a proto-typed intravascular ultrasound scanner capable of combined data acquisition in real-time. A wire phantom study shows that CPI-CTHI has a 12 dB lower range side lobe level and a 7 dB higher echo signal to noise ratio than PI-CTHI, while the lateral resolution and side lobe level are 50 μm finer and –3 dB less than fundamental chirp coded excitation imaging respectively. Ex vivo scanning of a rabbit trachea demonstrates that CPI-CTHI is capable of visualizing blood vessels as small as 200 μm in diameter with 6 dB better tissue contrast than either PI-CTHI or fundamental chirp coded excitation imaging. These results clearly indicate that CPI-CTHI may enhance tissue contrast with less range side lobe level than PI-CTHI. PMID:22871273

Observation of Intravascular Changes of Superabsorbent Polymer Microsphere (SAP-MS) with Monochromatic X-Ray Imaging

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

Tanimoto, Daigo, E-mail: daigoro@med.kawasaki-m.ac.jp; Ito, Katsuyoshi; Yamamoto, Akira

2010-10-15

This study was designed to evaluate the intravascular transformation behavior of superabsorbent polymer microsphere (SAP-MS) in vivo macroscopically by using monochromatic X-ray imaging and to quantitatively compare the expansion rate of SAP-MS among different kinds of mixtures. Fifteen rabbits were used for our study and transcatheter arterial embolization (TAE) was performed for their auricular arteries using monochromatic X-ray imaging. We used three kinds of SAP-MS (particle diameter 100-150 {mu}m) mixture as embolic spherical particles: SAP-MS(H) absorbed with sodium meglumine ioxaglate (Hexabrix 320), SAP-MS(V) absorbed with isosmolar contrast medium (Visipaque 270), and SAP-MS(S) absorbed with 0.9% sodium saline. The initial volumemore » of SAP-MS particles just after TAE and its final volume 10 minutes after TAE in the vessel were measured to calculate the expansion rate (ER) (n = 30). Intravascular behavior of SAP-MS particles was clearly observed in real time at monochromatic X-ray imaging. Averaged initial volumes of SAP-MS (H) (1.24 x 10{sup 7} {mu}m{sup 3}) were significantly smaller (p < 0.001) than those of SAP-MS (V) (5.99 x 10{sup 7} {mu}m{sup 3}) and SAP-MS (S) (5.85 x 10{sup 7} {mu}m{sup 3}). Averaged final volumes of SAP-MS (H) were significantly larger than averaged initial volumes (4.41 x 10{sup 7} {mu}m{sup 3} vs. 1.24 x 10{sup 7} {mu}m{sup 3}; p < 0.0001, ER = 3.55). There were no significant difference between averaged final volumes and averaged initial volumes of SAP-MS (V) and SAP-MS (S). SAP-MS (H), which first travels distally, reaches to small arteries, and then expands to adapt to the vessel lumen, is an effective particle as an embolic agent, causing effective embolization.« less

More Efficient Sodium Removal by Ultrafiltration Compared to Diuretics in Acute Heart Failure; Underexplored and Overstated.

PubMed

Kazory, Amir

2016-01-01

Enhanced removal of sodium has often been cited as an advantage of ultrafiltration (UF) therapy over diuretic-based medical treatment in the management of acute decompensated heart failure. However, so far clinical studies have rarely evaluated the precise magnitude of sodium removal, and this assumption is largely based on the physiologic mechanisms and anecdotal observations that predate the contemporary management of heart failure. Recent data suggest that patients treated with UF experience substantial reduction in urinary sodium excretion possibly due to prolonged intravascular volume contraction. Consequently, the efficient sodium extraction through production of isotonic ultrafiltrate can be offset by urine hypotonicity. Based on the limited currently available data, it seems unlikely that the persistent benefits of UF could be solely explained by its greater efficiency in sodium removal. The design of the future studies should include frequent measurements of urine sodium to precisely compare the impact of UF and diuretics on sodium balance. © 2016 S. Karger AG, Basel.

RhoA-stimulated intra-capillary morphology switch facilitates the arrest of individual circulating tumor cells.

PubMed

Huang, Xi; Yang, Yu; Zhao, Yuwei; Cao, Dan; Ai, Xiaolin; Zeng, Anqi; Gou, Maling; Cai, Lulu; Yang, Hanshuo; Zhao, Chengjian

2018-05-15

Metastasis is the primary cause of death for most cancer patients. Hematogenous arrest of circulating tumor cells (CTCs) is an essential prerequisite for metastases formation. Using transparent transgenic zebrafish (kdrl:eGFP; Casper), together with resonant laser scanning confocal microscopy, we tracked the fate of CTCs in vivo in the blood circulation for days. We found the intra-capillary morphology-switch (ICMS) of individual CTCs from strip to sphere was necessary for their intravascular arrests. Further genetic and pharmacological inhibition experiments indicated that the RhoA signaling was necessary for ICMS and the arrest of CTCs. At last, we demonstrated that early treatment by a clinically approved RhoA/ROCK inhibitor, Fasudil, could efficiently inhibit the initial arrest of individual CTCs and reduce the incidence of tumor metastasis in both zebrafish and mouse models. These results together indicate that RhoA-stimulated ICMS represents a mechanism for the arrest of individual CTCs, providing a potential target for future treatments of hematogenous metastatic disease. © 2017 UICC.

[Three-dimensional endoscopic endonasal study of skull base anatomy].

PubMed

Abarca-Olivas, Javier; Monjas-Cánovas, Irene; López-Álvarez, Beatriz; Lloret-García, Jaime; Sanchez-del Campo, Jose; Gras-Albert, Juan Ramon; Moreno-López, Pedro

2014-01-01

Training in dissection of the paranasal sinuses and the skull base is essential for anatomical understanding and correct surgical techniques. Three-dimensional (3D) visualisation of endoscopic skull base anatomy increases spatial orientation and allows depth perception. To show endoscopic skull base anatomy based on the 3D technique. We performed endoscopic dissection in cadaveric specimens fixed with formalin and with the Thiel technique, both prepared using intravascular injection of coloured material. Endonasal approaches were performed with conventional 2D endoscopes. Then we applied the 3D anaglyph technique to illustrate the pictures in 3D. The most important anatomical structures and landmarks of the sellar region under endonasal endoscopic vision are illustrated in 3D images. The skull base consists of complex bony and neurovascular structures. Experience with cadaver dissection is essential to understand complex anatomy and develop surgical skills. A 3D view constitutes a useful tool for understanding skull base anatomy. Copyright © 2012 Sociedad Española de Neurocirugía. Published by Elsevier España. All rights reserved.

Split-mode ultrasonic transducer.

PubMed

Ostrovskii, Igor; Cremaldi, Lucien

2013-08-01

A split-mode ultrasonic transducer is investigated in both theory and experiment. This transducer is a two-dimensional structure of periodically poled domains in a ferroelectric wafer with free surfaces. The acoustic vibrations are excited by a radio frequency electric current applied along the length of the wafer, which allows the basal-plane surfaces to be free of metal coatings and thus ready for further biomedical applications. A specific physical property of this transducer consists of the multiple acousto-electric resonances, which occur due to an acoustic mode split when the acoustic half-wavelength is equal to the domain length. Possible applications include ultrasonic generation and detection at the micro-scale, intravascular sonification and visualization, ultrasound therapy of localized small areas such as the eye, biomedical applications for cell cultures, and traditional nondestructive testing including bones and tissues. A potential use of a non-metallized wafer is a therapeutic application with double action that is both ultrasound itself and an electric field over the wafer. The experimental measurements and theoretical calculations are in good agreement.

Novel Percutaneous Radiofrequency Ablation of Portal Vein Tumor Thrombus: Safety and Feasibility

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

Mizandari, Malkhaz; Ao, Guokun; Zhang Yaojun

2013-02-15

We report our experience of the safety of partial recanalization of the portal vein using a novel endovascular radiofrequency (RF) catheter for portal vein tumor thrombosis. Six patients with liver cancer and tumor thrombus in the portal vein underwent percutaneous intravascular radiofrequency ablation (RFA) using an endovascular bipolar RF device. A 0.035-inch guidewire was introduced into a tributary of the portal vein and through which a 5G guide catheter was introduced into the main portal vein. After manipulation of the guide catheter over the thrombus under digital subtraction angiography, the endovascular RF device was inserted and activated around the thrombus.more » There were no observed technique specific complications, such as hemorrhage, vessel perforation, or infection. Post-RFA portography showed partial recanalization of portal vein. RFA of portal vein tumor thrombus in patients with hepatocellular carcinoma is technically feasible and warrants further investigation to assess efficacy compared with current recanalization techniques.« less

The clinical value of tissue factor assays.

PubMed

Francis, J L; Carvalho, M; Francis, D A

1995-06-01

Tissue factor (TF) is now considered to be the primary physiologic activator of the blood coagulation system. Coupled with recent advances in our understanding of the biochemistry of TF this has heightened interest in measuring aspects of TF activity in disease states. Expression of TF by blood monocytes in various diseases is an established trigger for intravascular coagulation and there is now a considerable body of experience with its measurement. This has considerable clinical potential although more widespread application awaits a consensus on the most appropriate methodologic approach to its measurement. TF can be detected in urine and may reflect the activation state of renal macrophages. Urinary TF is increased in cancer and could have diagnostic and prognostic value in a variety of malignant diseases. Finally, it is now possible to measure soluble TF in plasma. One such assay is commercially available and is technically simple to perform. The clinical value of such assays, however, must await better understanding of the source and function of soluble TF in plasma.

Face, content, and construct validity of human placenta as a haptic training tool in neurointerventional surgery.

PubMed

Ribeiro de Oliveira, Marcelo Magaldi; Nicolato, Arthur; Santos, Marcilea; Godinho, Joao Victor; Brito, Rafael; Alvarenga, Alexandre; Martins, Ana Luiza Valle; Prosdocimi, André; Trivelato, Felipe Padovani; Sabbagh, Abdulrahman J; Reis, Augusto Barbosa; Maestro, Rolando Del

2016-05-01

OBJECT The development of neurointerventional treatments of central nervous system disorders has resulted in the need for adequate training environments for novice interventionalists. Virtual simulators offer anatomical definition but lack adequate tactile feedback. Animal models, which provide more lifelike training, require an appropriate infrastructure base. The authors describe a training model for neurointerventional procedures using the human placenta (HP), which affords haptic training with significantly fewer resource requirements, and discuss its validation. METHODS Twelve HPs were prepared for simulated endovascular procedures. Training exercises performed by interventional neuroradiologists and novice fellows were placental angiography, stent placement, aneurysm coiling, and intravascular liquid embolic agent injection. RESULTS The endovascular training exercises proposed can be easily reproduced in the HP. Face, content, and construct validity were assessed by 6 neurointerventional radiologists and 6 novice fellows in interventional radiology. CONCLUSIONS The use of HP provides an inexpensive training model for the training of neurointerventionalists. Preliminary validation results show that this simulation model has face and content validity and has demonstrated construct validity for the interventions assessed in this study.

Potential roles of cell-derived microparticles in ischemic brain disease.

PubMed

Horstman, Lawrence L; Jy, Wenche; Bidot, Carlos J; Nordberg, Mary L; Minagar, Alireza; Alexander, J Steven; Kelley, Roger E; Ahn, Yeon S

2009-10-01

The objective of this study is to review the role of cell-derived microparticles in ischemic cerebrovascular diseases. An extensive PubMed search of literature pertaining to this study was performed in April 2009 using specific keyword search terms related to cell-derived microparticles and ischemic stroke. Some references are not cited here as it is not possible to be all inclusive or due to space limitation. Cell-derived microparticles are small membranous vesicles released from the plasma membranes of platelets, leukocytes, red cells and endothelial cells in response to diverse biochemical agents or mechanical stresses. They are the main carriers of circulating tissue factor, the principal initiator of intravascular thrombosis, and are implicated in a variety of thrombotic and inflammatory disorders. This review outlines evidence suggesting that cell-derived microparticles are involved predominantly with microvascular, as opposed to macrovascular, thrombosis. More specifically, cell-derived microparticles may substantially contribute to ischemic brain disease in several settings, as well as to neuroinflammatory conditions. If further work confirms this hypothesis, novel therapeutic strategies for minimizing cell-derived microparticles-mediated ischemia are available or can be developed, as discussed.

Dural venous sinuses distortion and compression with supratentorial mass lesions: a mechanism for refractory intracranial hypertension?

PubMed Central

Qureshi, Adnan I.; Qureshi, Mushtaq H.; Majidi, Shahram; Gilani, Waqas I.; Siddiq, Farhan

2014-01-01

Objective To determine the effect of supratentorial intraparenchymal mass lesions of various volumes on dural venous sinuses structure and transluminal pressures. Methods Three set of preparations were made using adult isolated head derived from fresh human cadaver. A supratentorial intraparenchymal balloon was introduced and inflated at various volumes and effect on dural venous sinuses was assessed by serial intravascular ultrasound, computed tomographic (CT), and magnetic resonance (MR) venograms. Contrast was injected through a catheter placed in sigmoid sinus for both CT and MR venograms. Serial trasluminal pressures were measured from middle part of superior sagittal sinus in another set of experiments. Results At intraparenchymal balloon inflation of 90 cm3, there was attenuation of contrast enhancement of superior sagittal sinus with compression visualized in posterior part of the sinus without any evidence of compression in the remaining sinus. At intraparenchymal balloon inflation of 180 and 210 cm3, there was compression and obliteration of superior sagittal sinus throughout the length of the sinus. In the coronal sections, at intraparenchymal balloon inflations of 90 and 120 cm3, compression and obliteration of the posterior part of superior sagittal sinus were visualized. In the axial images, basal veins were not visualized with intraparenchymal balloon inflation of 90 cm3 or greater although straight sinus was visualized at all levels of inflation. Trasluminal pressure in the middle part of superior sagittal sinus demonstrated a mild increase from 0 cm H2O to 0.4 cm H2O and 0.5 cm H2O with inflation of balloon to volume of 150 and 180 cm3, respectively. There was a rapid increase in transluminal pressure from 6.8 cm H2O to 25.6 cm H2O as the supratentorial mass lesion increased from 180 to 200 cm3. Conclusions Our experiments identified distortion and segmental and global obliteration of dural venous sinuses secondary to supratentorial mass lesion and increase in transluminal pressure with large volume lesions. The secondary involvement of dural venous sinuses may represent a mechanism for refractory intracranial hypertension. PMID:24920987

Application of Near Infrared Spectroscopy, Intravascular Ultrasound and the Coronary Calcium Score to Predict Adverse Coronary Events

DTIC Science & Technology

2012-10-01

hospitalization 9. Emergence of rhythm disturbances requiring treatment 10. Development of acute coronary syndrome 11. Cerebrovascular accident Adverse...catheterization. These will include coronary injury including dissection, perforation or occlusion, death, cerebrovascular accident , myocardial... cerebrovascular accident , bleeding, infection, arrhythmia, access site damage, coronary dissection, coronary thrombosis and myocardial infarction, among

Extravasation injuries.

PubMed

Chiu, Kenneth; Tindholdt, Tyge Tind; Tønseth, Kim Alexander

2016-02-09

It is common for an intravascular catheter to be inserted to administer various types of therapy. Extravasation occurs frequently, and in the most severe cases plastic surgeons are often summoned to assess the extent of the injury and the possibility for reconstruction. The Department of Plastic and Reconstructive Surgery at Oslo University Hospital assesses approximately 15 severe cases of this type each year.

B1 field-insensitive transformers for RF-safe transmission lines.

PubMed

Krafft, Axel; Müller, Sven; Umathum, Reiner; Semmler, Wolfhard; Bock, Michael

2006-11-01

Integration of transformers into transmission lines suppresses radiofrequency (RF)-induced heating. New figure-of-eight-shaped transformer coils are compared to conventional loop transformer coils to assess their signal transmission properties and safety profile. The transmission properties of figure-of-eight-shaped transformers were measured and compared to transformers with loop coils. Experiments to quantify the effect of decoupling from the B1 field of the MR system were conducted. Temperature measurements were performed to demonstrate the effective reduction of RF-induced heating. The transformers were investigated during active tracking experiments. Coupling to the B1 field was reduced by 18 dB over conventional loop-shaped transformer coils. MR images showed a significantly reduced artifact for the figure-of-eight- shaped coils generated by local flip-angle amplification. Comparable transmission properties were seen for both transformer types. Temperature measurements showed a maximal temperature increase of 30 K/3.5 K for an unsegmented/segmented cable. With a segmented transmission line a robotic assistance system could be successfully localized using active tracking. The figure-of-eight-shaped transformer design reduces both RF field coupling with the MR system and artifact sizes. Anatomical structure close to the figure-of-eight-shaped transformer may be less obscured as with loop-shaped transformers if these transformers are integrated into e.g. intravascular catheters.

Pacific Pediatric Advanced Care Initiative

DTIC Science & Technology

2009-10-01

Prepare IV ports:  Identify IV ports (UVC, Femoral venous line, other central venous lines, or PIV) for easy access to push meds or administer volume...Supply Department CVL central venous line CXR chest xray DC discontinue DI Diagnostic Imaging DIC disseminated intravascular coagulation diff...programs at KMCWC. These include the blood bank, blood utilization committee, clinical laboratories, operating room, central supply, pharmacy