The objective of this study was to investigate the effects of isovolemic hemodilution with dextran-70 on thrombus formation and blood flow in synthetic venous vessel grafts. Polytetrafluoroethylene grafts (length, 11 mm; inner diameter, 3 mm) were inserted into the vena cava of rabbits. Six groups were studied: (1) the control ...

BACKGROUND: A low-flow situation in arterial and venous grafts has been associated with high rates of perioperative infarction and mortality. This study was designed to look at intraoperative graft flow and resistance in patients with coronary artery disease. METHODS: Coronary artery bypass graft flow was measured in 46 patients. Transit-time ...

The change in blood flow after anastomosis and the effects on the anastomosed artery of different classes of vasodilators such as lidocaine and chlorpromazine given topically (n = 10 in each group), and prostaglandin E1 (PGE1)(n = 12) and diltiazem hydrochloride (n = 10) given systemically, were investigated in the ...

BACKGROUND: Anastomotic quality is currently the critical issue in minimally invasive coronary surgery. Although little is known about its effectiveness, surgeons routinely assess grafts intraoperatively using flow probes. This study was designed to determine whether mean flow and the pattern of flow tracing in internal mammary artery grafts obtained with ...

OBJECTIVE: To measure non-invasively the impedance index of a range of geometries of PTFE end-to-side anastomoses (ESA). DESIGN: In vitro experiments using a custom-built flow rig. SUBJECTS: Anastomoses constructed at each angle. (15 degrees, 30 degrees, 45 degrees, 60 degrees, 90 degrees, 120 degrees) for both standard and cuffed ESA. ...

The stabilities of two types of polymerically stabilized liposomes consisting of PEG-grafted (DSPC:CHOL:DSPE-PEG1900, 5:4:1) and physically adsorbed carboxymethylchitin (CMC) and carboxymethyl/glycolchitin (CO) are compared. The polyelectrolyte is adsorbed on positive (DSPC:CHOL:DMTAP, 5:4:1) and neutral (DSPC:CHOL, 1:1) liposomes at different molecular weights (Mw). In PBS buffer (c(s) = 154 mM, pH ...

PURPOSE: Our laboratory has developed methods required to covalently bind recombinant hirudin (rHir) to the surface of polyester vascular grafts. Using alkaline hydrolysis of the polyester surface, carboxyl-binding sites are created on the outer periphery of each fiber. A series of static, in vitro experiments have demonstrated that surface-bound rHir ...

When vascularized fibula grafts are used in mandibular reconstruction, it is often necessary to divide the graft into segments so as to follow the mandibular curvature. The periosteal blood supply to the segments is usually sufficient. It is unclear, however, how short the segments can be without compromising the blood ...

We report the case of a 70-year-old female who experienced a graft enteric erosion (GEE) three years after a right aorto-femoral bypass. She was treated by right axillo-femoral bypass, removal of the aortic prosthesis and direct aortic suture. The duodenum was stitched up and separated from the aorta by omentoplasty. ...

OBJECTIVES: This study sought to assess the flow dynamics of internal mammary artery grafts (IMAGs) in no-flow situations by use of a Doppler guide wire. BACKGROUND: Functionally no-flow and anatomically patent IMAGs have been reported by angiography in patients with a patent recipient coronary artery. METHODS: The study included 12 ...

Perioperative spasm of the internal mammary artery (IMA) may result in early restriction of bypass flow. Therefore, pharmacological pretreatment is usually suggested. We present a technique of temporary distal occlusion of the transsected IMA using a metal clip. After 1 hour of storage in normal saline (SAL) there were significantly ...

Plasticized polyvinyl chloride (PVC), although not a blood-compatible polymer, is the material of choice for the manufacture of blood bags and hemodialysis tubing throughout the world. PVC is usually plasticized with di-(2-ethylhexyl phthalate) (DEHP) to impart flexibility and low temperature properties to the final product. DEHP belongs to a class ...

Adverse physiological effects can often interfere with the use of nitric oxide (NO) as a therapeutic agent, especially when it is systemically generated from prodrugs. NO which is generated and delivered site-specifically by transdermal donors may be useful in the treatment of parasitic, bacterial or viral skin infections without causing ...

Thermal coronary angiography is a noninvasive but not yet quantitative method to intraoperatively assess graft patency in CABG surgery. Aim of this study was to quantify graft flow by measuring perfusion-induced myocardial temperature changes over time. Saphenous vein grafts to the left anterior descending artery were perfused at flow rates ...

A series of dapsone-related 4-aminopheynl and 2-aminothiazolyl derivatives was prepared, and their antinephritic activity and blood toxicity were evaluated. 5-(2-Pyridylsulfonyl)-2-thiazolamine (FR115092, 26) was effective against two nephritis models, namely graft-versus-host disease (GVHD) and autoimmune W/BF1 mice, and showed none of the blood toxicity observed with dapsone.

INTRODUCTION: Under certain conditions (small internal mammary artery (IMA) or large runoff), double grafting of the left anterior descending (LAD) artery system is necessary to avoid the ominous consequences of myocardial hypoperfusion. Previous studies have shown that a saphenous vein (SVG) adjacent to an IMA graft leads to failure of ...

Color flow doppler ultrasound examination of the hemodialysis access was conducted in 2,792 hemodialysis patients to evaluate its value in predicting hemodialysis access failure. After baseline assessment of vascular access function with clinical and laboratory tests including color flow doppler evaluation these patients were followed for a minimal of 6 ...

The pharmacologic response of coronary artery bypass conduits is of great importance. This study was designed to clarify the response of blood flow between the internal thoracic artery (ITA) and the ileocecal artery (ICA) to inotropic agents. The responses of the ITA and ICA to epinephrine, dopamine, isoproterenol, and dobutamine ...

BACKGROUND: Dobutamine (a beta-receptor agonist), enoximone (a type III selective phosphodiesterase inhibitor), and epinephrine (an alpha- and beta-mimetic) frequently are used in the perioperative management of patients undergoing coronary artery bypass grafting. METHODS: We performed a double-blind clinical study to compare the effects on internal mammary artery free flow of ...

We retrospectively reviewed 290 cases in which an albumin-impregnated polyester prosthetic graft was used for surgical management of aortic bifurcation disease between November 1987 and December 1990. The purpose of this review was to determine the incidence and volume of blood transfusion and to evaluate the rate of patency and ...

The authors sought to create a saphenous vein interposition graft to be used in cerebral bypass procedures that would be more physiologically appropriate than standard vein grafts and would provide a better match between the graft and recipient vessels at the anastomotic sites. The saphenous vein graft was prepared by ...

We have previously shown that high shear stress inhibits growth of developing neointima in a primate model of polytetrafluoroethylene (PTFE) graft healing. We used this model to test the hypothesis that increased shear stress can cause atrophy of an established neointima. High porosity PTFE grafts were inserted into the aorto-iliac ...

Venous pressures (VP) measured by the dialysis machine are widely used for access surveillance and have significantly improved outcomes. VP reflect the resistance in the venous outflow tract, which will rise in the presence of stenosis. Low graft flow caused by high graft resistance predicts thrombosis. In this study we ...

The authors attempted to develop a reliable and reproducible new animal model in which the blood-flow velocity to a flap could be varied. This model was utilized to study the effects of different blood-flow velocities on the patency rate of small 1- to 2-mm vessels after common microsurgical procedures. Male ...

PURPOSE: Nitric oxide (NO) not only relaxes vascular smooth muscles, but it also reduces platelet adhesion and is itself a potent antiaggregatory substance. Experimental studies have shown that the release of NO is modulated by the blood flow. However, little clinical information is available about the effects of hemodynamic changes ...

Fibrin glue is hemostatic in skin grafting and other therapeutic situations. This prospective, open-labeled comparative study involved thermally injured patients: 34 patients received fibrin sealant (FS) and 61 did not, at Loyola University Medical Center, Maywood, Illinois, and Shriners Burn Institute, Cincinnati, Ohio. FS-treated patients were 23.6 +/- 16.8 years ...

Porous poly(glycidyl methacrylate-co-ethylene dimethacrylate) monoliths with different porous properties grafted with poly(2-acrylamido-2-methyl-1-propanesulfonic acid) chains using cerium(IV) initiated free-radical polymerization have been prepared and used for the separation of proteins in ion-exchange HPLC mode. Because of the presence of the large pores that are typical of monolithic separation media which allow ...

Surgeons have traditionally relied on ring preparations to predict how arterial bypass conduits will behave in the postoperative circulation. OBJECTIVE: This study compared pharmacologic [norepinephrine (NE) challenge] and physiologic [arterial preload] responses of gastroepiploic (GEA) and internal thoracic (ITA) arteries in a standard static ring preparation and a dynamic perfusion ...

The purpose of this study was to determine the blood supply to lyophilized amniotic membranes when used as graft material in vestibuloplasties. 133Xe clearance technique was used to measure the blood flow to the grafts. A total of 20 patients had either Clark (10) or Kazanjian (10) vestibuloplasties. The blood ...

Recent studies have suggested that competitive flow is an important factor in early internal mammary artery (IMA) graft failure. Flow competition from minimally diseased native coronary vessels has been implicated in the failure of IMA grafts, but does not seem to affect saphenous vein grafts (SVG). The objective of this ...

Coronary artery bypass surgery is used widely for treating myocardial ischemia. However, blood flow and flow reserve of normally perfused myocardium subtended by bypass grafts have not been evaluated late after surgery. Also, it is unknown whether pharmacologic vasodilation evokes comparable myocardial flow responses in arterial and venous conduits. Myocardial ...

BACKGROUND: A simple, rapid, inexpensive method for measuring the flow in a patient's vascular access would permit routine monitoring during haemodialysis, and hence provide information of access graft deterioration sufficiently early to increase the success of minimally invasive remedial procedures. This paper reports the validation of such a method in ...

BACKGROUND: By current convention, the liver graft is revascularized, first with portal blood flow, and thereafter with arterial blood flow. Although experimental studies showed no detrimental effects of primary arterialization, this order of revascularization has not been investigated in clinical transplants. STUDY DESIGN: Twenty-nine patients were included in our controlled ...

Management of deep dermal hand burns represents a difficult clinical problem for the burn team because bedside estimation of burn depth is unreliable. Early identification of full-thickness injury and prolonged healing times might result in the decision to perform surgical excision of eschar and skin grafting of the wounds. Such ...

PURPOSE: Clinical studies have revealed that the most important predictor of successful bypass grafting is the origin and quality of the bypass conduit. Attempts at intraoperative evaluation of the hemodynamic properties of the conduit, including assessment of blood flow (Q), pressure gradients (delta P), and resistance (R), have not been ...

OBJECTIVE: Competitive flow from patent native coronary vessels is implicated in the failure of internal thoracic artery (ITA) grafts, but it is not thought to affect saphenous vein graft (SVG) patency. This study examines instantaneous pressure and flow dynamics in left ITA and SVG grafts in competition with a patent ...

BACKGROUND: This study examines whether the measurement of internal thoracic artery (ITA) graft flow can determine the adequacy of the ITA-left anterior descending coronary artery (LAD) anastomosis. METHODS: To study a wide range of clinical problems, we used a computer simulation of the cardiovascular system. The model included a time-varying ...

BACKGROUND: In the past, routine coronary graft flow measurement at the end of coronary artery bypass grafting (CABG) was not universally adopted by cardiac surgeons due to the lack of reliable flow measurement techniques. The purpose of this study was to investigate the efficacy of ultrasonic and electromagnetic techniques in ...

Primary dysfunction (PDF) and eventual primary nonfunction (PNF) of liver allografts have been characterized by various clinical and laboratory parameters reflecting graft function, cellular integrity and extrahepatic influence following orthotopic liver transplantation (OLT). During the past 6 yr we have been able to demonstrate that this potentially devastating condition is ...

Vascular prostheses of small diameter perform poorly in vivo, in part because of the high thrombogenicity of available biomaterials. This study examined the thrombogenicity of expanded polytetrafluoroethylene (ePTFE) vascular graft segments (10 mm long x 4 mm i.d.) in vitro before and after impregnation with saline, alginate, or alginate containing ...

Intra-graft injection of the prostacyclin analogue, iloprost, was performed at the end of femorodistal bypass procedures in 12 patients with severe peripheral arterial occlusive disease. Iloprost plasma levels were measured and compared with changes in haemodynamics. There was a high initial iloprost plasma level (mean 625 pg/ml) which dropped to ...

PURPOSE: We evaluated fibrin glue, laser welding, and a mechanical suturing device (Endo-Stitch) as alternatives to standard laparoscopic suturing with a free needle. METHODS: In 14 pigs, 22 linear proximal ureterotomies were closed laparoscopically with one of 4 different methods: fibrin glue, laser welding, Endo-Stitch suture placement (4-0 polyglactin), and ...

Transinterstitial blood loss at implantation and the degree of graft incorporation and inner capsule thickening was compared in serial explants of albumin-coated Dacron versus blood preclotted Dacron grafts in the canine thoracoabdominal aortic position (8 mm internal diameter x 30 cm length). The coated grafts were Bard DeBakey Vasculour II ...

In-vivo velocity profiles were recorded with a 20 MHz 80-channel pulsed Doppler ultrasound velocimeter in canine end-to-side ilio-femoral anastomotic grafts. The geometries were obtained from casts of the anastomotic region, and flow rates were measured with electromagnetic flow probes. Three cases reported here include a "standard" geometry, which was similar ...

An anatomic study was undertaken to establish whether positioning of the leg and surgical approaches for total hip replacement (THR) cause changes in the femoral v. which may contribute to the development of deep vein thrombosis (DVT). The patency of 32 femoral vv. of 18 cadavers was inspected at different ...

The aim of this study is to evaluate the thrombogenic behaviour of the low density polyethylene and poly(vinyl chloride) modified by radiation-grafting technique. After copolymerization with acrylic acid by gamma-rays from a 60Co source, BSA was immobilized onto functionalized graft copolymers. The biological interaction between these materials and blood was ...

The cartilage-flow phenomenon has been frequently described but not in connection with transplantation procedures for treatment of cartilage lesions. Consequently, we examined this particular phenomenon in an experimental sheep model originally set up to study the use of perichondrial grafts for repair of full-thickness cartilage lesions. Osteochondral lesions were made ...

In many cases of long-gap congenital esophageal atresia, direct anastomosis is difficult. In these cases, the esophagus is first lengthened by myotomy before anastomosis. We determined the degree of submucosal blood flow and/or approximation force at the site of anastomosis in rabbits after (1) separation of the esophagus from the ...

To evaluate the direct effect of nitric oxide (NO) on vascular smooth muscle cell (SMC) proliferation in vivo, we used an expanded polytetrafluoroethylene (ePTFE)-based local infusion device to deliver an NO donor, proline/NO (PROLI/NO), to the luminal boundary layer of endarterectomized artery and the distal anastomosis of the graft in ...

A case of cranial defect in the anterior fontanelle region is reported. The patient suffered a deep contact burn on the right parietofrontal region in the neonatal period. At age 3 years, a bone defect of 30 x 20 mm was observed in the right parietofrontal region, including the anterior ...