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

The most common causes of leg ulcers in elderly patients are arteriosclerosis obliterans, venous insufficiency, hypertension, and prolonged pressure over relatively small body areas. The goal of treatment is to clear infection and stimulate good granulation tissue that can accept either a skin graft or epithelial regrowth from the borders of the ulcer.
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PMID:Leg ulcers in the elderly. 37 6

Thirteen patients with chronic venous insufficiency of the legs, mostly with ulcerations, were treated during four weeks by pressure wave therapy following the method of Strehler. Some parameters of circulation, blood, and immunology were controlled at the beginning, at the third, tenth, twentieth and fourtieth day. There was a tendency to normalization of hypo- and hypertension, of the blood calcium and kalium, and especially, there was a significant increase of IgG and C'4 during the treatment with decrease of the IgM. Other parameters did not show specific alterations. The mobilisation of edema by pressure wave therapy seems to arise an immunologic reaction, probably by activating antigens or antigen-antibody complexes.
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PMID:[Triggering of immunologic reactions by Strehler's pressure wave therapy in patients with chronic venous insufficiency]. 68 81

The division of the venous circulation in to two sectors, one constituted by the superficial and deep venous trunks (macrocirculation) and the other by the capillaries and precapillary venules (microcirculation), is surely schematical but aids the comprehension of many hemodynamic effects connected to hampered venous return and to the incompetence of the valvular devices. In fact many of the effects of stasis and venous hypertension (oedema, red cell diapedesis, skin dystrophies) cannot be explained merely by hydraulic mechanisms but require a primary alteration of the microvascular wall associated with structural changes of the perivascular connective tissue. The alterations that occur in microcirculation are of the utmost importance in the formation of the venules ulcerations. The passage of fibrinogen through large pores in the venules of the patients affected by venous hypertension derived from venous insufficiency creates a pericapillary fibrin deposition that cannot be removed because of inadequate blood and tissue fibrinolysis. This accumulation acts as a barrier to the diffusion of oxygen and other nutrients, determining a stasis dermatitis that may lead to tissue necrosis and ulceration. The more precise knowledge of the phenomena connected with the venous stasis at the level of microcirculation (pericapillary fibrin deposition, endothelial ischemia, blocked lymphatic drainage) will not only allow a deeper comprehension of the clinical signs but hopefully will lead to a more effective treatment of the postphlebitic syndrome.
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PMID:[Physiopathology of venous stasis at the microcirculation level]. 129 20

Venous ulceration is the result of progressive chronic venous insufficiency, the pathophysiology of which is complex and incompletely understood. Ambulatory venous hypertension in this disease has been well-documented; however, relatively little attention has been directed toward other parameters of venous function. This study evaluates a spectrum of hemodynamic variables and the degree to which they are altered in patients with venous ulceration, and correlates ambulatory venous pressure (AVP) with the noninvasive estimate of this parameter. Air-plethysmography was used to evaluate 36 ulcerated extremities from 30 patients with chronic venous disease and 80 asymptomatic extremities from 54 patients. This technique measures the functional venous volume (VV), assesses valvular function [Venous Filling Index (VFI)], evaluates the efficiency of the calf muscle-pump [Ejection Fraction (EF)], and provides an estimation of ambulatory venous pressure [Residual Volume Fraction (RVF)]. In addition, AVP's were recorded in 13 asymptomatic extremities from 10 patients and 16 ulcerated extremities from 14 patients with chronic venous disease. Significant differences existed between the two groups for all of the hemodynamic parameters. Ulcerated extremities had greater venous volumes, displayed marked deterioration in valvular competence and calf muscle-pump function, and showed significant ambulatory venous hypertension compared to the asymptomatic group. Additionally, the relationship between RVF and AVP appeared linear, with a correlation coefficient of 0.87. Air-plethysmography currently provides the most complete evaluation of venous hemodynamics and should improve our understanding of the pathophysiology of chronic-venous disease.
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PMID:The hemodynamics of venous ulceration. 154 69

When adipose tissue enlarges in obesity, as the result of an imbalance between caloric intake and caloric expenditure, many changes occur in the cellular components of the adipose mass. A combination of increased cell size and number underlies the accretion of the adipose mass, however, only a reduction in cell size is possible with weight loss. Several metabolic abnormalities accompany obesity--most important--hyperinsulinemia, hyperlipidemia, insulin resistance, and carbohydrate intolerance. Clinical consequences of obesity include hypertension, venous insufficiency, gallbladder disease, osteoarthritis, pulmonary and cardiovascular insufficiency, diabetes, and atherosclerotic cardiovascular disease, and all are dependent on the severity and duration of the obesity. Once established, obesity is difficult to correct because of the development of many adaptive mechanisms by which obesity defends itself.
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PMID:Cellular, metabolic, and clinical consequences of adipose mass enlargement in obesity. 180 21

Plugging of skin capillaries by activated white blood cells is one of the proposed mechanisms by which skin damage may be initiated in chronic venous insufficiency. The aim of this study was to determine whether a microcirculatory deficit was induced in the skin by raising the venous pressure proximally for thirty minutes. Seventeen subjects with no evidence of venous or arterial disease had laser Doppler velocimetry performed in the goiter region of the leg; 8 different subjects had the measurement done on the dorsum of the hand. Peak hyperemic response following three minutes of ischemia was measured before and after a thirty-minute period of sustained venous hypertension applied by a proximal tourniquet inflated to 80 mm Hg. A decrease in the peak flow: baseline flow ratio (median ratio 2.25 before, 1.70 after, p less than 0.02) and an increase in the time taken to reach maximal hyperemia (median time ten seconds before, twenty seconds after, p less than 0.01) were observed after the period of venous hypertension in the lower limb. The second parameter, but not the first, was significantly affected in the upper limb. The authors conclude that a microvascular deficit in the skin is demonstrable after a short period of venous hypertension. This is consistent with the white-cell-trapping theory, but other possible explanations are discussed.
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PMID:The effect on skin blood flow of short-term venous hypertension in normal subjects. 182 74

The aim of this study was to understand the possible mechanisms by which deep venous insufficiency and venous hypertension are associated with trophic skin changes and ulceration and to explain the therapeutic effect of Pentoxifylline in patients with leg ulcers due to deep venous incompetence. Twenty patients were included in this pilot study. They were graded into two groups: group 1, included 10 patients (5 F and 5 M) with deep venous incompetence and normal arteries; group 2, included 10 patients (1 F and 9 M) with deep venous incompetence and moderate arterial disease. Skin and muscle biopsies were carried out before and after the oral administration of 1,200 mg of Pentoxifylline daily (400 mg t.d.s). The following parameters were investigated by means of light microscopy and immunofluorescence tests: engorgement of venous stroma; decrease of intimal elastica; hyaline degeneration; floccular degeneration; pericapillary fibrin deposits and fibrin degradation products; inflammation and fat necrosis; myofibril degeneration; fibrous scar; regeneration and reconstitution of muscle fibres. The results indicated that local inflammation at the ulcer's area cause accumulation of white blood cells in the capillaries and the interstitial fluid, where there is also accumulation of fibrinogen. These changes may lead to chronic tissue ischaemia and ulceration. The known favourable effect of Pentoxifylline on red cells and leucocyte function as well as its lowering effect on plasma fibrinogen level, may be responsible for the observed therapeutic effect of Pentoxifylline on venous leg ulcers.
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PMID:Comparison of skin and muscle biopsies before and after pentoxifylline treatment in patients with leg ulcers due to deep venous incompetence. 186 Oct 90

In vascular diseases, when the vasomotor reserve is exhausted, microcirculation is strongly dependent on blood fluidity. For patients with vascular disorders, it was therefore decided to evaluate red blood cells (RBC) aggregation and disaggregation (SEFAM erythro-aggregometer) which are important factors determining blood viscosity in low flow areas. Our results show that, in essential hypertension (EH), RBC aggregation is significantly increased (+15%), and disaggregation is decreased (-20%). The highest frequency of troubles was found in EH. This observation led to exclusion of EH subjects in all the other studied pathological groups. When EH is excluded from a group of 70 patients with cerebrovascular disorders (CVD), we did not observe significant changes in RBC aggregation. However, in essential and post-thrombotic venous insufficiency there remains a significant increase in RBC aggregation (+10%) and a decrease in disaggregation (-13%). In diabetes, disaggregation is more disabled than for controls (-16%). In all these pathologies presence of EH magnifies the abnormalities, or makes them appear like in CVD. This study underlines the critical importance of taking the influence of hypertension into consideration when evaluating RBC aggregation in vascular pathology. The increase in RBC aggregability and in the shear resistance of the aggregates, when present in vascular pathology, is likely to add a burden to the circulatory system already hindered by a deficient vasomotor regulation system.
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PMID:[Erythrocyte aggregation in vascular disease. Influence++ of hypertension]. 194 Jun 53

Interest in white cell (WBC) rheology has largely been directed towards hypotensive conditions. However, as capillary flow is dependent on the relative arteriovenous pressure gradient, we investigated the dynamics of WBC flow in patients with venous hypertension. Three groups of matched subjects were studied: normal controls, patients with primary varicose veins, and patients with deep venous insufficiency confirmed by foot volumetry and Doppler studies. A venous cannula inserted at the level of the medial malleolus allowed blood samples to be taken at time 0 (supine) and then at 15, 30, 45, and 60 minutes after sitting up. Further samples were taken after subjects resumed a supine position. After 60 minutes sitting the haematocrit of blood leaving the foot increased by 9.6% in controls and 25.6% in patients with venous insufficiency. The difference in the behaviour of WBC was more marked. Controls showed a 5.0% decrease in the relative number of WBC after 60 minutes sitting compared to 28% decrease in patients with venous insufficiency. On resuming a supine position there was a significant increase in the number of WBC leaving the foot and this "wash-out" appeared to be delayed in the two patient groups. Platelets showed a corresponding fall when the foot was dependent but there appeared to be no washout after elevation.
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PMID:Increased white cell trapping in the dependent legs of patients with chronic venous insufficiency. 201 Jul 4

Based on a retrospective evaluation of 107 patients with congenital venous angiodysplasia of the Type Klippel-Trenaunay (n = 76) and Type Servelle-Martorell (n = 31) the frequency and pathogenesis of aneurysma formation in the venous system has been analysed. The vascular patterns include both cylindric ectasia and fusiform aneurysms with an incidence of approximately 40%. Preferred locations are subcutaneous drainage veins, the popliteal, external iliac vein and atypic communicating veins between the superficial and the deep venous system. Complications of the aneurysm such as local thrombosis, recurrent pulmonary embolism or bleeding from ruptur were not observed. The aneurysma formation in venous angiodysplasias results probably from the causative factors: congenital weakness of the venous wall and an abnormal hemodynamical stress situation. The latter is caused by concomitant malformations of the deep venous system. The persistent intermittent venous hypertension associated with a more or less pronounced increase of the venous volume in the affected venous system of the limb results in a deep venous insufficiency respectively venous reflux disease. The therapy of choice is predominantly conservative, i.e., external compression bandages or stockings to reduce the deleterious effects of a chronic deep venous insufficiency respectively venous reflux disease. Surgery is indicated under two conditions: a) in the presence of aneurysm complications or b) for the elimination of a pathological short circuit flow in some drainage veins. Antireflux surgery, i.e., venous valve transfer from the brachial vein, is up to recently still in a stage of experimental-clinical investigation.
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PMID:Aneurysma transformation in congenital venous angiodysplasias in lower extremities. 217 53


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