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Query: UMLS:C0022116 (ischemia)
 91,303 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

In this paper the authors try to specify the leg ulcers physiopathology. They have first studied the vascular deficits, and they are able to conclude that this deficit is not the only factor responsible for the thrombosis. They try to rediscover the factors which could lead to the thrombosis, on the created local conditions (circulatory slackening, cooling, ischemia), by using clinical and biological "check-ups" as well as an exploration of the clotting. In many patients we find an anomaly such as: clotting "check-ups" disturbance, thrombocyte hyperaggregability, fibrinolysis deficit, antithrombin III deficit, cryoprecipitate, circulating immune complexes, hepatic "check-up" alteration. It is difficult to establish an accurate relation between these anomalies and a thrombosis but the frequent existence of such anomalies makes us think that they play a part in the ulcerations coming-up.
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PMID:[Leg ulcer. Vascular and thrombosis factors. Each responsibility of those factors? (author's transl)]. 50 59

As part of a major clinical trial, sequential biopsies were taken from the margins of venous leg ulcers during their healing. The changing patterns of tissue architecture and extracellular matrix synthesis during healing were documented histologically and immunocytochemically. Initial biopsies were similar in appearance: prominent fibrin cuffs, variable inflammation, hemosiderin, and red blood cell extravasation. So called "fibrin cuffs" were highly organized structures composed of laminin, fibronectin, tenascin, and collagen as well as trapped leukocytes and fibrin. Fibronectin was absent from the ulcer tissue although collagen was abundant. Major histologic changes were observed after 2 weeks' pressure bandage therapy; hemosiderin, acute inflammation, and granulation tissue with the deposition of fibronectin had all increased and epithelial migration had commenced. Complete epithelialization was frequent by the fourth week of treatment, but the basement membrane was incomplete. At this time, hemosiderin and red blood cell extravasation had decreased and "fibrin cuffs" were virtually absent although chronic inflammation remained. The complex organization of the so-called "fibrin cuffs" may inhibit angiogenesis (but offer protection against increased venous pressure) in addition to their previously ascribed role in causing tissue ischemia.
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PMID:Sequential changes in histologic pattern and extracellular matrix deposition during the healing of chronic venous ulcers. 127 79

Lyophilized type I collagen (L.C.) can stimulate wound healing by recruiting a number of different cell types (i.e. platelets and macrophages) and proteins (i.e. fibronectin). Platelets and macrophages produce locally-acting growth factors that in turn induce fibroblast and epidermal migration, angiogenesis and increase matrix synthesis. Chronic leg ulcers (C.L.U.) are the end result of microvascular failure owing to ischemia and stasis. When L.C. has been used in the treatment of C.L.U. we have observed that: a) it is significantly more effective in stimulating the healing of chronic venous ulcers when compared to hydrocolloids (p less than .05), the two products being applied upon half of the same ulcer; b) in the treatment of C.L.U. due to arterial obstruction L.C. is more effective than hydrocolloids without achieving statistical significance; c) it is very effective in the treatment of C.L.U. in thalassaemic patients; d) telethermographic studies have demonstrated an increase of blood perfusion and histological studies have shown the stimulation of angiogenesis, fibropoiesis and epidermal growth; e) the application of L.C. determines the maximum obtainable increase also under conditions of proven cicatrization difficulty; and f) enzymatic degradation of L.C. has not promoted any bacterial infection and no local or generalized sensibilization phenomena have been observed. We can conclude that L.C. is a pharmacological approach to wound healing, directly interfering with cellular and non-cellular components, and significantly improves the reparative process when delayed.
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PMID:Lyophilized type-I collagen and chronic leg ulcers. 172 86

Much of the morbidity and mortality in sickle cell disease (SCD) is caused by tissue ischemia and infarction resulting from vascular occlusion. Research in this area has been dominated by the hypothesis that vascular occlusion in SCD is due primarily to microvascular obstruction by sickle erythrocytes (SS RBC), yet there is no direct evidence that microvascular occlusion is responsible for any of the vasocclusive complications of SCD. In this paper an alternate hypothesis is proposed: that thrombotic occlusion of larger arteries and veins is an important factor in many of the vasocclusive complications of SCD. Large-vessel cerebral arterial disease (intimal hyperplasia with superimposed thrombosis) has clearly been established as the most important cause of stroke in SCD, and considerable evidence suggests that pulmonary arterial thrombosis/embolism is a major cause of pulmonary infarction and hypertension. The involvement of large-vessel thrombosis in painful crisis, aseptic necrosis of bone, priapism, leg ulcers, retinopathy, and miscarriage has not been adequately investigated. Large-vessel occlusion in SCD is probably a consequence of the abnormal adhesive and procoagulant properties of SS RBC, which produce endothelial damage, secondary intimal proliferation, and thrombosis. Techniques currently used to treat large-vessel occlusion in other disorders (antiplatelet and anticoagulant agents, thrombolytic therapy, angioplasty, endarterectomy, and vascular bypass surgery) should be considered in sickle cell subjects with large-vessel occlusion, especially in the cerebral vasculature.
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PMID:Large-vessel occlusion in sickle cell disease: pathogenesis, clinical consequences, and therapeutic implications. 189 Sep 82

Blood flow within the skin is measured by evaluating the dynamics of the laser speckle pattern. Laser light scattered from an object with a rough surface forms a granular structure--the speckles. When the object is moving, the speckle pattern becomes dependent on time. The measurements are performed at a distance of 6 cm which is adjusted by an auxiliary beam. The laser beam forms a spot on the skin with a diameter of approximately 1.5 mm and penetrates the skin. Part of the light is scattered back to the surface by the blood cells in the capillaries. The time dependent speckle intensity I(t) is determined by a photomultiplier. The comparison of spectra of I(t) obtained from measurements on the skin and on adhesive tape attached to the skin shows that there is a "tissue movement", the velocity of which has the same order of magnitude as the blood velocity in the capillaries. This has to be considered when measuring blood flow by the speckle method. Electronic signal processing reduces the influence from tissue movement and yields a value M being a relative measure of the blood flow. The time course of M during ischemia and reactive hyperaemia is compared with concurrent measurements of the skin temperature, the transcutaneous oxygen tension, and the laser Doppler signal. They exhibit similar tracings. Investigations in patients with leg ulcers show that measurements in open wounds can be performed.
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PMID:Blood flow determination by the laser speckle method. 232 96

The case of a woman with systemic lupus erythematosus with unusual clinical, cutaneous and biologic features and lupus anticoagulant is presented. According to the literature this association is not fortuitous: a new syndrome characterized by the presence of a subgroup of antiphospholipid antibodies has been recognized. The cutaneous symptoms of this syndrome include: leg ulcers, livedo reticularis, widespread cutaneous necrosis and distal cutaneous ischemia. In our patient a nearly complete picture of the clinical and biologic features of this syndrome, including a characteristic retinal vein thrombosis is present.
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PMID:[Clinical manifestations associated with the presence of lupus anticoagulant]. 250 30

Currently lumbar sympathectomies are infrequently performed because the effectiveness of the procedure is unclear. The previous indication of limb-threatening ischemia has been usurped by distal arterial reconstruction. Some vascular surgeons feel there is no remaining clinical role. This paper suggests four categories of patients, represented by five case reports, where lumbar sympathectomy may prove beneficial: 1) Hypertensive patients with painful leg ulcers; 2) Toe and foot amputations in which arterial reconstruction is not feasible; 3) Posttraumatic causalgia (sympathetic dystrophy); 4) As an adjunct to distal graft bypass.
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PMID:Lumbar sympathectomy: a place in clinical medicine. 261 43

Two patients with the lupus anticoagulant exhibited unusual cutaneous manifestations. They both fulfilled four criteria for systemic lupus erythematosus and had experienced deep venous thrombosis. The first patient suffered from a leg ulcer that resembled a pyoderma gangrenosum. The second patient presented erythematous and purplish macules on the fingertips. The histologic studies showed only microthrombosis in the dermal vessels without vasculitis, although such lesions in systemic lupus erythematosus are usually attributed to vasculitis. The association of these cutaneous lesions with lupus anticoagulant has never been reported. It is likely that this association is not fortuitous. After a review of the literature, it seems possible to individualize a new syndrome characterized by the presence of a subgroup of antiphospholipid antibodies. Thrombosis, spontaneous abortions, neurologic manifestations, pulmonary hypertension, positive results of a Coombs' test, and thrombocytopenia can be included in this syndrome, which overlaps with systemic lupus erythematosus. Certain cutaneous symptoms are associated with the presence of lupus anticoagulant or other antiphospholipid antibodies: leg ulcers, distal cutaneous ischemia, widespread cutaneous necrosis, and livedo. They can be considered as the dermatologic manifestations of this syndrome.
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PMID:Cutaneous manifestations associated with the presence of the lupus anticoagulant. A report of two cases and a review of the literature. 309 56

The local arterial blood supply was evaluated according to clinical criteria in 30 consecutive patients with chronic leg ulcers. Separately, the blood pressure was measured at the ankle level with both strain gauge plethysmography and a Doppler ultrasonic method. In patients with clinical signs of arterial obliterative disease the systolic ankle pressure and the ankle/arm systolic pressure ratio were lower than in patients without such signs. In none of the patients was the local pressure decreased to such a degree that ischemia was the main cause of the ulcer, nor was gangrene imminent. Hence, success or failure of skin grafting or conservative treatment depends primarily on factors other than the nutritive flow, when the perfusion pressure is above 70 mmHg, as in the present study.
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PMID:Local blood pressure in chronic leg ulcers. 616 6

Since the incidence of inflammatory arterial disease has been higher in Japan, its surgical treatment has been one of the main themes of vascular surgery from its beginning in this country. Buerger disease has been the main cause of chronic occlusive arterial disease before the middle of 1970s. and many patients suffered from intractable ischemic leg ulcer with severe pain. Reconstructive surgery, however, has been so much limited that number of the candidates for bypass surgery were around 10% of the patients, because of distal nature of the disease. We have developed a new technique in distal bypass surgery named as Esmarch's rubber bandage method, which was intended to minimize surgical injury to the host artery, and the results of its application to Buerger disease is very encouraging, and we have confirmed that this technique enables a bypass to the collateral arteries and muscular branches in place of the diseased tibio-peroneal artery. We expect this technique will clear a new avenue to surgical treatment of Buerger disease with limb threatening ischemia. In Takayasu's arteritis, the carotid reconstruction was popular between the late 1950s and 1960s and, at the same time atypical coarctation, renovascular hypertension, and aneurysm, along with their combined lesion became the objects of vascular surgery. This expansion of surgical indication contributed to the improvement of the prognosis and rehabilitation of the patients. Long term function of the reconstruction has been also confirmed. On the other hand, several problems emerged with the widespread application of vascular reconstruction which were peculiar to the disease state. Among them, the most important problems were neurological complications due to sudden increase in the intracranial blood pressure after carotid reconstruction, and anastomotic aneurysm as the delayed complication affecting eventual outcome which are inherent to the inflammation and extensive destruction of the medial component in this disease. A new method to prevent the postoperative neurological complications is discussed in this report. To improve the long term survival, meticulous observation of postoperative course is essential in Takayasu's arteritis. Recently, abdominal aortic aneurysms showing the peculiar gross appearance and clinical presentation have become the subject of discussion as inflammatory abdominal aortic aneurysm because of remarkable thickening of the aneurysmal wall and a severe inflammatory change, and some difficulties of its surgical treatment have been stressed in the most of the reports. The recent researches offered the conclusion that etiology of the aneurysm is not inflammation, but inflammatory reaction during formation of atherosclerotic aneurysm.(ABSTRACT TRUNCATED AT 400 WORDS)
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PMID:[Surgical treatment of intractable vasculitis syndromes--with special reference to Buerger disease, Takayasu arteritis, and so-called inflammatory abdominal aortic aneurysm]. 793 11


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