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Ihler Fritz - - 2012
Abstract Objective: Impairment of microcirculation is a possible cause of sudden sensorineural hearing loss (SSNHL). Fibrinogen is known as a risk factor for both microvascular dysfunction and SSNHL. Therefore, the aim of this study was to investigate the effect of elevated serum levels of fibrinogen on cochlear blood flow and ...
Kumazaki Setsuo - - 2010
Left internal mammary artery (LIMA) bypass conduits undergo gradual longitudinal flow transition from the proximal to distal segments, and the diastolic/systolic (D/S) ratios of the flow indices can diagnose graft patency. However, the influence of graft adaptation on this has not been studied. We examined 46 patients with LIMA graft ...
Laustsen Jesper - - 2010
The objective was to study the intraoperative hemodynamic effects of closure of residual arteriovenous fistulae during in situ saphenous vein graft procedures. Data on 60 residual arteriovenous fistulae in nine patients (five men) with a median age of 74 years (range 64-83 years) with critical lower limb ischemia were obtained. ...
Webb Carolyn M - - 2010
Radial artery (RA) aortocoronary bypass grafts anastomosed to a branch of the circumflex coronary artery have significantly better patency rates than saphenous vein (SV) grafts at 5 years, but the physiological characteristics and mechanisms involved are not clearly defined. We compared RA and SV graft vasomotor and flow responses to ...
Heise Michael - - 2010
The long-term prognosis of arteriovenous polytetrafluoroethylene (PTFE) hemodialysis grafts remains poor, causing significant morbidity and costs. The high failure rate is due to a stenosis development of the graft-vein anastomosis, consisting of two pathophysiologically separate and characteristic lesions emerging from two main mechanisms: development of intimal hyperplasia in the vein ...
Nordgaard Håvard - - 2010
Competitive flow from native coronary vessels is considered a major factor in the failure of coronary bypass grafts. However, the pathophysiological effects are not fully understood. Low and oscillatory wall shear stress (WSS) is known to induce endothelial dysfunction and vascular disease, like atherosclerosis and intimal hyperplasia. The aim was ...
Malik Jan - - 2010
Background: Vascular accesses (especially polytetrafluoroethylene grafts) with a permanently low flow (Qa <600 ml/min) are prone to thrombosis and thus have short patency. The reason for a permanently low flow is usually medial calcinosis of the inflow artery in diabetics. We retrospectively studied the long-term patency of low-flow grafts with ...
Tsagakis Konstantinos - - 2010
PURPOSE: To evaluate the impermeability to blood of the modified E-vita open plus hybrid stent-graft in animal experiments and initial clinical applications in the replacement of the ascending aorta and aortic arch combined with antegrade stent-grafting of the descending aorta. METHODS: In 3 acute pig experiments, a tightly woven hybrid ...
Amin-Hanjani Sepideh - - 2010
PURPOSE: There is much debate regarding the optimal strategy for extracranial-intracranial (EC-IC) bypass for complex aneurysms. We introduce the concept of a flow replacement bypass which aims to compensate for loss of flow in the efferent vessels of the aneurysm. The strategy to achieve this utilizes direct intraoperative flow measurements ...
Bourquelot P - - 2010
OBJECTIVE: Juxta-anastomosis proximal radial artery ligation (PRAL) is a new surgical technique for reduction of excessive blood flow of radial cephalic fistulas (RCFs). PATIENTS AND METHODS: This prospective study included 37 consecutive patients (eight children and 29 adults) who underwent PRAL of high-flow RCFs causing ischaemia (n = 2), aneurysmal ...
Marx Roger - - 2010
OBJECTIVES: Arterial revascularization with the internal thoracic artery (ITA) has shown exceptional long-term results, even though early hypoperfusion can occur and can cause ischemia and contractile dysfunction. Therefore, it is still controversial as to whether the bypass vessel can guarantee the required demand for blood flow during the early postoperative ...
Neville Richard F - - 2011
Hemodynamic factors at the distal anastomosis play an important role in prosthetic graft performance. A new magnetic resonance imaging (MRI) technique was used to determine the effect of anastomotic geometry on hemodynamic flow patterns. Four dimensional (4D) magnetic resonance velocimetry (4D-MRV) is a noninvasive method of analyzing pulsatile flow in ...
Nordgaard Håvard B - - 2010
Transit-time flow measurement is widely accepted as an intra-operative assessment in coronary artery bypass grafting (CABG). However, the two most commonly applied flowmeters, manufactured by MediStim ASA and Transonic Inc., have different default filter settings of 20 and 10 Hz, respectively. This may cause different flow measurements, which will influence ...
Zhou Juan - - 2009
Effects of electrospinning parameters (including voltage, collection distance, solution concentration and flow rate) on the morphology and diameter distribution of regenerated SF (silk fibroin) fiber were investigated. Afterward, SF tubular scaffold composed of homogenous fibers was fabricated at voltage of 18kV, collection distance of 18cm, concentration of 37%, and flow ...
Kretschmer W B - - 2010
Autologous blood donation is not currently recommended by most authors for routine bimaxillary osteotomies. There are few data about bimaxillary procedures with multisegmental maxillary osteotomies. Our aim was to investigate the effect of additional osteotomies and iliac crest grafts on operative blood loss. A total of 225 consecutive patients having ...
Agarwal Pawan - - 2009
Traditional wisdom is that wound healing is directly related to haemoglobin level in the blood; therefore blood transfusion is given in anaemic patients to raise the haemoglobin level for better wound healing. Evaluation of wound healing in the form of split thickness skin graft take was done in 35 normovolaemic ...
Kenagy Richard D - - 2009
High blood flow through baboon polytetrafluorethylene aorto-iliac grafts increases neointimal vascular smooth muscle cell (SMC) death, neointimal atrophy, and cleavage of versican to generate the DPEAAE neoepitope, a marker of ADAMTS-mediated proteolysis. In this study, we have determined the effect of high blood flow on transcript abundance in the neointima ...
Zheng Tinghui - - 2009
The use of helix geometry for arterial grafts has been proposed on the hypothesis that by intentionally inducing swirling or spiral flow in the grafts, hemodynamic performance of the grafts might be improved. To investigate their hemodynamic performance, the present study numerically simulated the flows in the helical grafts, not ...
Madershahian Navid - - 2009
OBJECTIVE: Numerous reports have been performed to investigate the hemodynamic effects of intraaortic balloon pumping (IABP) and nonpulsatile circulatory extracorporeal membrane oxygenation (ECMO), but studies on its impact on coronary artery bypass graft flow during concomitant use of IABP and ECMO are lacking. The aim of this study was to ...
Frydrychowicz Alex - - 2009
We present preliminary data of the vascular hemodynamics in a novel, anatomically shaped ascending aortic graft in comparison to non-operated individuals by use of 3D magnetic resonance (MR) flow measurements. We examined a 72-year-old male patient after Tiron David I valve sparing aortic root reconstruction and replacement of the ascending ...
Nordgaard Håvard - - 2009
OBJECTIVE: To assess whether coronary graft flow patterns are affected differently by native coronary competitive flow or by stenosis of the coronary anastomosis. METHODS: Nine pigs (65-70 kg) underwent off-pump grafting of the left internal mammary artery to the left anterior descending artery (LAD). Transit-time flow patterns in the mammary ...
Kolonko Aureliusz - - 2009
BACKGROUND: Doppler flow spectrum, quantified in the segmental arteries of the graft early after kidney transplantation (KTx), reflects the exacerbation of interstitial oedema. In some patients, the spectrum is characterized by the absence of blood flow during part or during the whole diastole of the cardiac cycle. We have previously ...
Eichstaedt Harald C - - 2010
BACKGROUND: In autologous saphenous vein grafts, prostacyclin (PGI(1)), a vasoprotective molecule produced by normal endothelial cells, is down-regulated compared with ungrafted saphenous veins and normal carotid arteries. Reduced PGI(2) synthesis may contribute to local platelet deposition, vascular smooth muscle cell (VSMC) accumulation, atherosclerosis, and ultimately failure of venous bypass grafts. ...
Maoz D - - 2009
BACKGROUND: Hemodialysis arteriovenous graft (AVG) patency is dependent on favorable flow characteristics. We examined hemodynamic, humoral risk factors, and the effects of stringent flow surveillance coupled with prompt corrective intervention on long-term graft patency. METHODS: Over a 29-month period 92 chronic hemodialysis patients with AVG were evaluated monthly by flow ...
Greenwood John - - 2009
During the first 48 hours after placement, an autograft "drinks" nutrients and dissolved oxygen from fluid exuding from the underlying recipient bed ("plasmatic imbibition"). The theory of inosculation (that skin grafts subsequently obtain nourishment via blood vessel "anastomosis" between new vessels invading from the wound bed and existing graft vessels) ...
Weiss Dominik R - - 2009
The objective of this study was to gain deeper insight into the early reasons for saphenous vein graft disease and to find a practical approach to obviate it. Intraoperative storage of freshly explanted venous grafts (45 min, 20 degrees C; n=25 in each case) in saline, saline + 5% albumin, ...
Xiong F L - - 2009
Enhanced hemodynamics via geometric alteration is believed to play a role in the favorable redistribution of intimal hyperplasia (IH) in infragenicular supplementary vein cuffs. We aimed to elucidate the consequence of altering geometric configuration in anastomotic hemodynamics in cuff models. A well-validated numerical scheme was used to simulate pulsatile flows ...
Lindenblatt Nicole N Division of Plastic and Reconstructive Surgery, University Hospital Zurich, Zurich, Switzerland. - - 2008
Models of skin graft revascularization are based mostly on histologic evaluations but lack the possibility of analyzing the vascular biology in vivo. The aim of the present study was therefore to develop an animal model that allows continuous monitoring of the microcirculation during skin graft healing. Skin and subcutaneous tissue ...
Negaard A - - 2008
BACKGROUND: Magnetic resonance enteroclysis (MRE) is suggested to become the preferred radiological method in small-bowel Crohn's disease (CD). However, the performance of inexperienced readers may influence the diagnostic value of the method and has not been previously investigated. PURPOSE: To compare readings of MRE in small-bowel CD performed by experienced ...
Malikov S - - 2009
BACKGROUND: The haemodynamic effects of revascularisation with combined bypass and free-muscle flap remain controversial. In a porcine experimental model, we investigated the transplantation-induced changes in the haemodynamics of a Y-shaped combined arterial autograft bypass-muscle flap (AABF). METHODS: Anatomy of AABF was identified in eight dissections in four porcine cadavers. In ...
Ram Sunanda J - - 2008
During clinical application of flow surveillance of hemodialysis grafts, the risk of thrombosis is assessed month after month, rather than after one or several measurements, as has been done in published studies. Adequate assessment of risk should consider the many measurements obtained over time. Prospective cohort diagnostic test study. 176 ...
Zhang ZhiGuo - - 2008
Small-diameter vascular grafts are in large demand for coronary and peripheral bypass procedures, but present products still fail in long-term clinical application. In the present communication, a new type of small-diameter graft with a swirl flow guider was proposed to improve graft patency rate. Flow pattern in the graft was ...
Takami Yoshiyuki - - 2008
BACKGROUND: We investigated hemodynamic effects of intra-aortic balloon pumping (IABP) in in-situ and aorta-coronary (A-C) grafts during coronary artery bypass grafting (CABG). METHODS: One hundred seventy-two grafts, including 84 in-situ left internal thoracic arteries (LITAs), were examined intraoperatively with a transit-time flowmeter in 84 patients who had prophylactic IABP. The ...
Tokuda Yoshiyuki - - 2008
BACKGROUND: Transit time flow measurement has been accepted as a valuable tool to predict early coronary artery bypass graft failure immediately after surgery. However, if the graft is patent in the early postoperative period, the ability of transit time flow measurement to predict midterm graft failure is unknown. METHODS: Midterm ...
Aygün Hayati - - 2008
The objective of this study was to introduce the vertical mattress (VM) suture technique and compare its patency and postoperative healing with other commonly used suture techniques. Thirty-two Sprague-Dawley rats were randomly assigned to one of four suture techniques to be applied to both femoral arteries: continuous (C), interrupted (I), ...
Miyamoto Shimpei S Department of Plastic and Reconstructive Surgery, Kyorin University School of Medicine, Tokyo, Japan. - - 2008
This study aimed to compare several microvascular anastomotic techniques by patency rate using a free flap model in rats. A microsurgical transfer model of a pectoral skin flap to the cervical region was used. In experiment 1, 120 rats were divided into four groups (n = 30 in each group) ...
Ding Rongjing - - 2008
OBJECTIVE: As an important prognostic factor of coronary artery bypass grafting (CABG), graft vasospasm can be observed in all currently used graft conduits. Radial artery (RA) vasospasm is more prone to occur in comparisons with internal mammary artery (IMA) and great saphenous vein (GSV). There is still controversy about which ...
Dwyre D M - - 2008
Transfusion-associated graft-versus-host disease (TA-GvHD) is a rare complication of transfusion of cellular blood components producing a graft-versus-host clinical picture with concomitant bone marrow aplasia. The disease is fulminant and rapidly fatal in the majority of patients. TA-GvHD is caused by transfused blood-derived, alloreactive T lymphocytes that attack host tissue, including ...
Herman Christine - - 2008
Transit-time flowmetry enables immediate intraoperative assessment of blood flow parameters in coronary artery bypass grafts (CABG). The present study assesses the predictive value of measured graft flows on early and medium-term outcomes. All cardiac surgery patients with measured graft flows were included. The last intraoperative flow measurements recorded using the ...
Milburn J A - - 2008
PURPOSE: Our primary aims were (1) to examine the patency of transposed brachiobasilic (TBB) fistulae compared to arm arteriovenous graft (AVG) without prior transposition, and (2) to examine the patency of AVG with and without prior transposition. METHODS: Single institution; analysis of prospectively collected data between January 2001 and January ...
Min Seung-Kee - - 2008
Increased blood flow causes neointimal atrophy, whereas relief of wall tension with an external wrap causes arterial medial atrophy. To study the effects of blood flow and wall tension separately and together, we applied tight or loose wraps on high-flow or normal-flow iliac arteries in baboons. Baboon external iliac arteries ...
Fung George S K - - 2008
In treating thoracic aortic diseases, endovascular repair involves the placement of a self-expanding stent-graft system across the diseased thoracic aorta. Computational fluid dynamic techniques are applied to model the blood flow by numerically solving the three-dimensional continuity equation and the time-dependent Navier-Stokes equations for an incompressible fluid. From our results, ...
Misra Sanjay S Department of Radiology, Mayo Clinic College of Medicine, 200 First Street SW, Rochester, MN 55905, USA. - - 2008
Venous injury and subsequent venous stenosis formation are responsible for hemodialysis graft failure. Our hypothesis is that these pathological changes are in part related to changes in wall shear stress (WSS) that results in the activation of matrix regulatory proteins causing subsequent venous stenosis formation. In the present study, we ...
Bregy Amadé - - 2008
OBJECT: The treatment of complex cerebrovascular or skull base pathological conditions necessitates a microsurgical blood flow preservation or augmentative revascularization procedure as either an adjunctive safety measure or a definitive treatment. The brain is susceptible to ischemia, and procedure-related risks can be minimized by the reduction of occlusion time or ...
Zhang Jun-Mei - - 2008
As hemodynamics is widely believed to correlate with anastomotic stenosis in coronary bypass surgery, this paper investigates the flow characteristics and distributions of the hemodynamic parameters (HPs) in a coronary bypass model (which includes both proximal and distal anastomoses), under physiological flow conditions. Disturbed flows (flow separation/reattachment, vertical and secondary ...
Goettsch Winfried - - 2008
Endothelial cells are constantly exposed to high or low shear stress in arteries and veins by the flowing blood. Angiopoietin-2 (Ang-2) is acting as a critical regulator of vessel maturation and endothelial cell quiescence. In this study, flow-dependent regulation of Ang-2 was analyzed in vitro and in vivo. Ang-2 mRNA, ...
Bashar Abul Hasan Muhammad - - 2008
OBJECTIVES: Obstruction of blood flow through the arteria radicularis magna (ARM) has been linked with ischemic spinal cord injury after conventional thoracic aortic repair. Whether or not endoluminal stent-grafts, deliberately positioned against this artery can cause similar damage to the spinal cord has not been comprehensively investigated. The purpose of ...
Steyger Peter S PS Oregon Hearing Research Center; Oregon Health and Science University; Portland, Oregon - - 2008
Cochlear sensory hair cells are pharmacologically sensitive to aminoglycoside antibiotics that are used for treating life-threatening bacterial sepsis. Cochlear tissues are compartmentalized behind an impermeable paracellular barrier called the blood-labyrinth barrier (BLB). Most macromolecules cannot cross the blood-labyrinth barrier; however, aminoglycosides can cross this barrier into the cochlear fluids and ...
MaƂota Z - - 2007
OBJECTIVES: One of the most popular palliative procedures performed to increase pulmonary blood flow in children with congenital heart defects is a shunt operation (Blalock-Taussig graft or Glenn procedure), which creates the new blood channel to the pulmonary artery. The main problem with this kind of surgery is poor shunt ...
Qiao Aike - - 2008
In order to show the application of computational fluid dynamics in biomedical engineering, some numerical simulations of blood flow in arteries, such as hemodynamics of bypass graft for stenosed arteries, hemodynamics of stented aneurysm at the aortic arch, hemodynamics of bypass treatment for DeBakey III aortic dissection, and influence of ...
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