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Query: UMLS:C0020538 (hypertension)
 170,190 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The cause of venous ulceration remains unclear but recent evidence suggests that white cell trapping may play a significant role. In this study venous blood taken from the dependent leg of 15 normal subjects was compared to samples taken from a similar number of patients with deep venous insufficiency. About 25 p. cent fewer white cells and platelets left the dependent foot of the patients with venous hypertension. When the foot was elevated there was a significant washout of white cells but not platelets suggesting platelet consumption within the microcirculation of the dependent foot. In 8 of the patients these changes were reversed by external compression.
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PMID:White cell and platelet trapping in patients with chronic venous insufficiency. 324 94

Graded high-compression support hosiery have long been recognized as a physiologically significant mode of therapy for chronic venous disease because of their effects on the hemodynamics of venous return. Photoplethysmography (PPG) in the noninvasive vascular laboratory is now recognized as a quick, simple, and noninvasive measurement technique, which correlates well with ambulatory venous pressure in the postphlebitic limb with chronic venous insufficiency. The purpose of this study was to evaluate the hemodynamic effects, as measured by PPG, of 40 mm Hg graded compression support hosiery in the treatment of patients with a documented history of hospital-treated thrombophlebitis. Fifty lower extremities among 38 patients with a documented history of deep vein thrombosis and chronic venous insufficiency were matched against 50 control extremities among patients without disease. All 50 lower extremities in the study group had abnormal noninvasive venous studies, including Doppler ultrasound examination, phleborheography, and PPG (mean, 5.9. seconds). Thus these patients were ascertained to have incompetent deep venous systems, but with normal arterial flow as documented by ankle:brachial ratios. After application of 40 mm Hg gradient compression stockings to the study group, PPG measurements in all 50 limbs initially converted to normal (20.6 seconds). Abnormal PPG measurements were converted to normal in postphlebitic limbs with the application of graded compression stockings in the 29 patients who wore the prescribed hosiery; 21 patients did not wear the gradient stockings after the initial evaluation(s) and were not found to have improved PPG measurements. It can be concluded that such gradient stockings should be associated with a reduction in ambulatory venous pressure, which may, in turn, lead to clinical prevention or improvement of the various sequelae associated with chronic venous hypertension.
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PMID:Hemodynamic assessment of high-compression hosiery in chronic venous disease. 331 77

Increased interest in venous insufficiency has generated investigators to look for new insights to the pathophysiology of this disease. Previous clinical experience has revealed a relationship between venous hypertension and muscle atrophy in this group of patients. Phosphorous nuclear magnetic resonance studies has been done on a group of venous insufficiency patients to discover the biochemical changes.
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PMID:P31-NMR studies of muscle in patients with venous insufficiency. 362 54

Venous valve reconstruction in 31 limbs (28 patients) with chronic deep venous insufficiency is analyzed. The indications for operation were primary or secondary deep valvular incompetence with severe reflux and venous hypertension. Valvuloplasty was performed on a proximal valve of the superficial femoral vein (SFV) in 17 limbs and on a common femoral vein valve in two limbs; transplantation of a valve-bearing segment of the axillary vein was made to the common femoral vein in two limbs, to the SFV in seven limbs, and to the popliteal vein in three limbs. The results of valvuloplasty were satisfactory, with six failures observed during a follow-up period extending to 84 months (mean, 44 months). Eight of 12 valve transplant reconstructions failed within 2 years. Patency and competence of the reconstruction were obtained in 27 limbs at the 6-month postoperative control period. The effects on venous pressure were analyzed regarding the presence or absence of reflux into the profunda femoral vein (PFV) with preoperative retrograde phlebography. The results showed significant reduction of the ambulatory venous pressure (p less than 0.05) and increase in venous recovery time (p less than 0.01) in limbs with PFV competence. In limbs in which the PFV was incompetent the pressure values remained unchanged. These findings suggest that the functional state of the PFV is of great importance to the venous hemodynamics of the limb. This study also indicates that the principle of one-level repair in the SFV seems appropriate in limbs with a competent PFV.
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PMID:Influence of the profunda femoris vein on venous hemodynamics of the limb. Experience from thirty-one deep vein valve reconstructions. 376 84

Serious complications of local venous hypertension occur rarely in the upper extremity. These are most frequently the result of a dysfunctional arteriovenous fistula and may produce changes indistinguishable from those of chronic lower-extremity venous insufficiency. A combination of arterial and venous contrast imaging is essential for identifying major venous outflow obstruction and for planning appropriate surgical therapy.
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PMID:Varicose ulcer of the upper extremity. 403 80

The diagnosis of venous insufficiency and hypertension was established in 53 patients using standard diagnostic methods including ascending and descending venography, venous pressure measurements, and photoplethysmography. Autogenous vein valve transplant, which is gaining acceptance as a treatment for this condition, was employed in this group of patients to relieve venous valvular insufficiency. Biopsy specimens of the gastrocnemius muscle were obtained before surgery in all 53 patients and studied pathologically. Three types of morphologic injury were encountered, suggesting that disuse, denervation, and ischemia may each be partially responsible for damage in skeletal muscle subjected to venous insufficiency and hypertension. Skeletal muscle injury probably explains the preoperative elevations of serum creatine kinase levels in many of our patients and may account for the failure of venous pressures to return to normal levels following surgery.
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PMID:Muscle changes in venous insufficiency. 674 10

The skin pigmentation of chronic venous insufficiency is associated both with increased melanin production and also with deposition of haemosiderin. Following treatment by compression sclerotherapy this pigmentation usually decreases. Seven patients with varicose pigmentation were assessed prior to treatment by colour photographs and skin biopsies. About one year after sclerotherapy further photographs and biopsies were taken. Six of the patients showed a definite decrease of pigmentation on the photographs. In all seven the amount of melanin had decreased. The results for haemosiderin were less uniform and showed a variable rise or fall. It therefore seems likely that the discoloured legs of chronic venous insufficiency result from stimulation of melanocytes perhaps similar to a sunburn response or to the mechanism in haemosiderosis. In the same way this may be reversible when the stimulus of venous hypertension or ultraviolet radiation is removed. The haemosiderin discolouration may also result from extravasation of red cells through capillaries if blood leaks out of the tissues during injections without adequate pressure bandaging.
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PMID:The aetiology and treatment of varicose pigmentation. 707 Nov 86

A patient is reported with successful clinical recanalization of a thrombosed saphenous vein interposition graft in the superficial femoral vein after civilian injury. Primary repair of venous injuries may prevent both initial acute venous hypertension as well as the development of chronic venous insufficiency.
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PMID:Recanalization of a saphenous vein interposition venous graft. 723 Feb 89

A variable model of venous hypertension was used to examine the immediate effect on skin oxygenation and blood flow. Measurements were carried out using laser Doppler flowmetry, transcutaneous oximetry and both macro- and micro-lightguide spectrophotometry to measure haemoglobin saturation (SO2). Assessments were performed on 20 normal subjects and in ten patients with deep venous insufficiency lying supine with a pressure cuff left uninflated (P0), then inflated to 40 mmHg (P40), 60 mmHg (P60) and 80 mmHg (P80). All measurements were performed at the gaiter area of the leg. In normal subjects median Doppler values fell significantly at P40 (P < 0.001) but further pressure increases had no more effect. Mean values of transcutaneous partial pressure of oxygen (PtcO2) fell steadily (P < 0.001), although the initial fall at P40 was small. Median SO2 fell with increasing occlusion pressure with both macro- and micro-lightguide spectrophotometry (P < 0.001), although the main reduction occurred predominantly at lower occlusion pressures. Higher levels of SO2 were obtained with local heating up to 44 degrees C, with a pattern similar to that of PtcO2. In patients, the same pattern of response to increased venous pressure occurred in areas of clinically normal skin. These data suggest that small increases in venous hypertension have an immediate and profound influence on skin blood flow and oxygen availability in normal skin.
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PMID:Use of lightguide spectrophotometry to quantify skin oxygenation in a variable model of venous hypertension. 748 62

The consequences of chronic deep venous insufficiency are a major medical concern and result in significant loss of human productivity in addition to a significant compromise of lifestyles. The postphlebitic syndrome of chronic venous stasis and ulceration is a result of chronic venous hypertension and reflects a sequela of events occurring secondary to venous valvular insufficiency and reflux. Diagnostic techniques have advanced considerably; however, the prevention and management of this entity continue to be inadequate. Many new areas are being explored, both from a medical and a surgical perspective, and it is hoped that as clinical investigation proceeds, new conceptual approaches and techniques will arise to combat this difficult medical problem. The literature reviewed in this article reflects a spectrum of research attempting to understand the basic underlying hemodynamic as well as cellular and tissue changes that contribute to the development of postphlebitic signs and symptoms. More investigation is needed to enable us to proceed from the descriptive understanding of this entity to the mechanisms that result in this disease state. Preventive and curative management needs to succeed the current palliative approach to therapy.
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PMID:Chronic venous insufficiency. 749 65


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