Using duplex ultrasonography lower-limb blood flow measurements were obtained in 20 patients with intermittent claudication. Assessments of flow were made in the common femoral artery, profunda femoris artery (PFA) and superficial femoral artery (SFA) before and after angioplasty for stenoses of short segments of the SFA. Blood flow was measured ...

The objective of this study was to establish a probe system for intraoperative quantitative leakage measurement during selective limb perfusion for adjuvant high-dose chemotherapy in patients with malignant melanomas. We used a portable gamma probe with digital display and investigated the physical properties in a phantom study simulating blood pool ...

Defects in insulin stimulation of blood flow have been used suggested to contribute to insulin resistance. To directly test whether glucose uptake can be altered by changing blood flow, we infused bradykinin (27 microgram over 100 min), an endothelium-dependent vasodilator, into the femoral artery of 12 normal subjects (age 25+/-1 ...

PURPOSE: To compare, using Duplex ultrasonography, different intermittent pneumatic compression (IPC) systems to augment venous blood flow for deep venous thrombosis (DVT) prevention during and after surgery and during periods of immobility. METHODS: This cross-over study randomly assigned 26 young, healthy, adult subjects, without history of DVT, hypertension, diabetes, stroke. ...

We evaluated the use of coloured dye-extraction microspheres for measuring blood flow in the skeletal muscle of anaesthetized rabbits. Spheres were injected into the left atrium after sternotomy or lateral thoracotomy, or into the left ventricle via the left carotid artery. Both routes of administration produced adequate mixing of microspheres ...

To compare skeletal muscle microvascular blood flow at rest and during reactive hyperemia in septic patients, a prospective, controlled trial was conducted on 16 patients with severe sepsis and a control group of 10 patients free of infection in the intensive care unit of a university hospital. Systemic hemodynamics, whole-body ...

Tissue blood flow has been measured in Zucker lean and obese rats during treadmill exercise and later recovery, by using a fluorescent-dyed latex microsphere method. The procedure used allowed up to six different timed blood flow measurements in the same animal. Exercise resulted in grossly increased muscle blood flow, compensated ...

Regional hemodynamic responses to the vasodilators, hydralazine (1 mg/kg, i.v.) and verapamil (0.1 mg/kg/min, i.v.), were examined in conscious Wistar Kyoto rats (WKY) and spontaneously hypertensive rats (SHR), 15 and 50 weeks of age, using the radioactive microsphere method. The flow rates of heart and skeletal muscle in SHR were ...

A finite element description of blood perfusion has been developed, and is applied to skeletal muscles. Three-dimensional distributions of blood pressures and flows in deforming muscles are calculated. The muscle tissue is considered as a fluid-saturated porous solid. The blood is modeled as a series of five intercommunicating compartmental fluids, ...

The aim of this experimental study was to investigate whether lightguide spectrophotometry in the visible wavelength range in skin could be used to predict stump healing viability in patients with critical lower limb ischaemia. Remission spectra recorded at two sites (medial and lateral) on the line of a proposed trans-tibial ...

This study was designed to analyse the relationship between arterial hypertension and changes in arterial blood flow and vascular wall damage of the lower limbs in hypertensive patients with various degrees of hypertension. Six hundred and fifty-four hypertensive patients (421 males and 233 females) aged 35 to 70 years and ...

Blood flow to skeletal muscle is a potentially important factor in the reduction of muscle function associated with aging (sarcopenia). The main influence of reduced blood flow capacity on muscle function is in limiting oxidative metabolism. Direct measures of blood flow include: intravital-microscopy, plethysmography, radioactive microspheres, 133Xenon washout, thermodilution, and ...

BACKGROUND: Seal reproductive systems are surrounded by thermogenic muscle and insulating blubber, suggesting elevated temperatures at the gonads and uterus. In the limbs of terrestrial mammals, cooled blood returning from superficial veins is mixed proximally with warm blood returning from deep veins. Thus, mixed cool-superficial and warm-deep venous blood from ...

BACKGROUND: The cutaneous microcirculation vasodilates during acute 6 degrees head-down tilt (HDT, simulated microgravity) relative to upright conditions, more in the lower body than in the upper body. HYPOTHESIS: We expected that relative magnitudes of and differences between upper and lower body cutaneous blood flow elevation would be sustained during ...

The efficacy of propionyl-L-carnitine in increasing walking capacity in patients with peripheral arterial disease is primarily due to the metabolic effect of the drug, but a direct vasoactive action is also hypothesized. Muscular and subcutaneous blood flow of lower limbs were separately evaluated using the 133-Xenon washout technique in 10 ...

Temperature and microcirculatory blood flow studies have been measured before and after chemical sympathectomy in a patient with reflex sympathetic dystrophy of the left leg present for at least three years following surgery for glomus tumour. Normalisation of temperature and blood flow was associated with the relief of pain, present ...

A fetal lamb model of amniotic band syndrome (ABS) was developed to study the pathophysiology of banded extremities and evaluate the possibility of in utero treatment with the potential for functional recovery. Eight fetal lambs underwent banding of their extremities with umbilical tape at 100 days' gestation. Two lambs aborted ...

The indications for prolonged cardiopulmonary support or extracorporeal membrane oxygenation are expanding. A potential serious complication of these techniques is distal limb ischemia. Techniques have been developed to provide the distal limb with blood flow. Unfortunately, specialized skills and materials are required. We describe a simple method of providing distal ...

Multichannel laser Doppler flowmeters allow continuous, simultaneous measurement of perfusion in several organs. We measured microcirculatory blood flow in the kidney, liver, skin and skeletal muscle in 10 anaesthetized rats subjected to abdominal surgery and graded haemorrhage (withdrawal of 5% total blood volume every 10 min). Mean arterial blood pressure, ...

PURPOSE: Patterns of flow in superficial and deep veins and outward flow in medial calf perforators were studied by duplex ultrasonography scanning in 1653 lower limbs in 1114 consecutive patients. This study compares results in 776 limbs with primary uncomplicated varicose veins with those in 166 limbs with the complications ...

Ischemia of active skeletal muscle induces a reflex increase in sympathetic activity, heart rate, cardiac output, and arterial pressure, termed the muscle metaboreflex. Whether this pressor response contributes importantly in the regulation of blood flow to the ischemic active skeletal muscle is not well understood. If the pressor response is ...

A mathematical model of reactive hyperaemia has been developed, in which the limb vascular system is represented by an elastic porous tube, with flow in the tube equivalent to blood flow in the arteries and large arterioles. Flow through the porous walls represents flow into the small arterioles, which respond ...

Recent animal studies have demonstrated that selective blockade of ATP-sensitive K+ (KATP) channels of vascular smooth muscle results in a significant increase in peripheral vascular tone. The main aim of this study was to assess whether glyburide, a selective blocker of KATP channels and commonly used antidiabetic agent, influences resting ...

This study examined the peripheral endothelium-dependent vasodilatory response to acetylcholine and the endothelium-independent vasodilatory response to nitroprusside in 19 patients with chronic heart failure and eight controls. These peripheral blood flow responses were compared with hyperemic calf blood flow changes after maximum leg exercise and 5-min femoral occlusion. The peripheral ...

Intraoperative methods to assess skeletal muscle blood flow or muscle-flap perfusion during vascular reconstructive surgery are limited. At present, techniques enable only anatomic identification of the degree of patency of large vessels. We report here the first use of ultrasonography to assess dynamic changes in skeletal muscle perfusion. Baseline blood ...

Mental stress was induced by the Stroop colour word task (CW task) and the effects on the microcirculation and electromyography (EMG) in the upper portion of the trapezius muscle were studied during a series of fatiguing, standardized static contractions. A lowered blood flow of the skin recorded continuously by laser-Doppler ...

During repetitive contractions, the VO2 of the dog gastrocnemius-plantaris muscle rose with the contraction frequency up to a maximal value and then decreased as contraction frequency was increased further. PVO2 was constant over most of the contraction frequency range. Reducing perfusion pressure/blood flow reduced VO2max with a constant PVO2. During ...

Previous studies have shown that the muscle chemoreflex causes an augmented blood pressure response to exercise and partially restores blood flow to ischemic muscle. The purpose of this study was to investigate the effects of the muscle chemoreflex on blood flow to nonischemic exercising skeletal muscle. During each experiment, dogs ...

We examined the hypothesis that the initial decline (first 1-2 min) in force development that occurs in working muscle when blood flow is halted is caused by O2 availability and not another factor related to blood flow. This was tested by reducing O2 delivery (muscle blood flow X arterial O2 ...

Both legs of 29 patients with venous disease and those of 15 controls without venous disease were assessed by duplex ultrasonography. The duration of reverse flow after release of manual calf compression was measured in the common femoral, long saphenous, popliteal and short saphenous veins. Before undertaking the study, the ...

PURPOSE: The purpose of this study was to describe the combination of physiologic and anatomic changes present in limbs with venous ulceration. METHODS: Limbs with venous ulceration (chronic venous insufficiency [CVI] class 3) were assessed prospectively by air plethysmography and color-flow duplex scanning. Findings were compared with clinically normal contralateral ...

The present study compared the skeletal muscle and visceral blood flow patterns elicited by electrical stimulation of the hypothalamic defense area (HDA) and the hypothalamic vigilance area (HVA) of the rabbit. Electrical stimulation of the HDA evoked a pressor response, tachycardia, hyperventilation, an increase in blood flow to the skeletal ...

1. Two complimentary techniques were used to study cortical function in six human upper limb amputees: positron emission tomographic (PET) measurements of regional cerebral blood flow (rCBF) were made in subjects during limb movements to study activation of the primary motor (M1), primary somatosensory (S1), and association cortices; and electromyographic ...

The time courses of leg blood flow, systolic peak velocity, heart rate and blood pressure have been studied in nine health volunteers during dynamic exercise in upright sitting and in a tilted sitting body position. In both positions the subjects performed single and repeated foot plantarflexions against light and moderate ...

Pulse oximetry was used to detect return of pulsatile flow in 27 subjects during reactive hyperaemia following 3 min of total limb ischaemia induced by above knee tourniquet occlusion. Fourteen patients with exercise induced leg pain had 18 symptomatic limbs tested. Thirteen controls had 25 limbs tested. Return of pulsatile ...

The aim was to test within a randomized double-blind trial whether the platelet inhibitor ticlopidine might improve peripheral blood flow and distal pressures in patients with aortofemoral arteriosclerosis. One hundred and one patients with intermittent claudication were studied after one year, after two to three years, and after five years ...

In order to determine the effect of altering the method of delivery of lytic therapy, both hind limbs of 55 adult mongrel dogs were embolized to occlusion and divided into six different treatment groups. Each right limb received 100,000 units of urokinase (UK) intraarterially by one of six different treatment ...

An isotope limb blood flow technique was used to assess the outcome of technically successful balloon angioplasty. Measurements were made on a total of 120 limbs, before angioplasty and at least once after angioplasty at 3 weeks, 3 months, 6 months, 12 months and 2-5 years. 67% of treated limbs ...

A fibre-optic microbending sensor for clinical use in venous occlusion plethysmography (VOP) has been developed. The sensor utilizes the microbending principle to detect the volume expansion of a limb following venous occlusion. This principle is based on the loss of energy in an optical fibre that undergoes mechanical perturbations. A ...

We report a prospective, blinded comparison of compression ultrasound (US) and Tc-99m erythrocyte-labelled venous blood pool scintigraphy (BPS) in patients presenting with symptoms of deep venous thrombosis (DVT). Contrast venography (CV) was used as the gold standard. Ninety-eight lower limbs of 76 patients were examined. DVT was present at CV ...

The control of tissue blood flow is a dynamic process exemplified by the interaction among physical, chemical, and electrical events occurring within the vessel wall and between the vasculature and tissue parenchyma. The range of blood flow control achieved in vivo is illustrated by functional hyperemia in exercising skeletal muscle: ...

We have tested the hypothesis that isoflurane potentiates non-depolarizing neuromuscular block via an increase in muscle blood flow. Anaesthesia was induced with thiopentone 4-5 mg kg-1 in 30 adult male patients of ASA physical status I or II and was maintained with 70% nitrous oxide in oxygen supplemented with either ...

It has been generally accepted that pooling of the blood in the legs is one reason for the orthostatic intolerance experienced after space flights. This is also the reasoning behind the application of anti-G suits during reentry after space flights. Fighter pilots also use the anti-G suit, the hypothesis being ...

Earlier studies have proposed that the time to reach peak hyperaemic flux recorded with laser Doppler (tp) is a simple and accurate method of evaluating ischaemic limbs and possibly a method of estimating the peripheral vascular resistance (PR). The aim of this study was to investigate the relationship between the ...

The maintenance of adequate oxygen delivery (DO2) and tissue uptake (VO2) has become central dogma in the management of the critically ill. However, these parameters are derived using gas tensions measured in mixed venous blood and may not reflect changes in regional blood flow. Therefore, it has become necessary to ...

The hemodynamic effects of combined venoarterial injury and stasis were studied in the hindlimbs of 10 dogs. Femoral arterial blood flow and pressure, peripheral venous pressure, and peripheral resistance were measured after the restoration of blood flow following venoarterial injury and a 4-hour period of occlusion for up to 72 ...

This study evaluated microvascular perfusion in the human Achilles tendon by laser Doppler flowmetry (LDF) at rest, during vascular occlusion, and during passive stretch and isometric contraction of the triceps surae. In 40 healthy volunteers, an intratendinous needle probe was introduced 5 mm above the distal insertion, at the midportion, ...

In an animal model of hind limb ischemia we documented the levels of endogenous basic fibroblast growth factor (bFGF) in control and ischaemic hind limbs, and evaluated the response to the administration of exogenous recombinant bFGF and heparin. Variations in this model were tested for their ability to alter the ...

A computer aided set of equipment for impedance plethysmographic research has been presented. A simple linear model of blood circulation in a limb has been used. A comparative analysis of blood circulation parameters in lower extremities has been carried out manually as well as calculated automatically. Parameters such as the ...

This paper describes the application of radionuclide limb blood flow measurements in 60 patients presenting to the vascular surgeons with exercise-induced leg pain. All patients were considered to be diagnostic problems since either their symptoms were atypical for peripheral vascular disease, or they had normal peripheral pulses and/or a normal ...