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

The clinical manifestations and prognosis of peripheral vascular disease (PVD) depend upon the severity of limb hypoxia. Transcutaneous oxygen tension (Ptco2) is related to tissue oxygenation, but limb Ptco2 varies with changes in systemic as well as peripheral oxygen delivery (Do2). Previously we have found that simultaneous assessment of limb and chest Ptco2 yields a ratio, or regional perfusion index (RPI), that is independent of systemic Do2 and accurately reflects the adequacy of limb perfusion. Analysis of segmental limb Ptco2, RPI, and position-induced RPI changes was performed in 24 control limbs and 14 limbs with intermittent claudication (IC), 8 limbs with rest pain (RP), and 7 limbs with gangrene (G). Control limbs had high RPI values that varied little with position. The IC group had modestly decreased RPIs in the supine position, but extremity RPIs decreased markedly during leg elevation. Patients with RP had ischemia while supine, but the RPI improved to nearly normal upon standing. Feet with G were hypoxic even in the standing position. Segmental RPI decreases correlated with the presence of significant arterial lesions. This correlation was unaffected by diabetes. Analysis of regional transcutaneous oximetry allows classification of PVD by quantitative criteria based upon the adequacy of limb perfusion under functional conditions. RPI is characteristically high in normal persons and low in persons with G. Limbs with marginally compensated perfusion may have nearly normal RPI values under some conditions, but typical ischemic changes are elicited by positional change and exercise. The ease of such provocation of RPI decreases constitutes an index of the severity of disease. Such quantitative assessments of limb hypoxia can form the basis for a physiologic approach to arterial reconstruction.
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PMID:Pathophysiologic classification of peripheral vascular disease by positional changes in regional transcutaneous oxygen tension. 672 5

In order to develop transcutaneous oxygen tension (PtcO2) measurements into a practical method for assessing peripheral vascular disease, the relationships between extremity and chest wall PtcO2 were examined in subjects with and without systemic atherosclerotic disease. The ratio of extremity to chest PtcO2, or transcutaneous regional perfusion index (RPI) assessed limb oxygenation more reliably than did direct PtcO2 measurement by obviating the effects of changes in systemic oxygen delivery upon local PtcO2. The authors find that transcutaneous oximetry can be used during treadmill exercise testing and that the RPI is unchanged by exercise in all normal subjects. PtcO2 and RPI were then measured during rest, position change, and exercise testing in patients with intermittent claudication. Whereas normal subjects maintain a constant thigh and calf RPI during exercise, patients with intermittent claudication consistently manifested large decreases in RPI in these areas when they were exercised until symptomatic. The authors find no overlap between the responses of normal subjects and patients with claudication; positive findings are, therefore, highly specific for exercise-induced limb ischemia. Since transcutaneous RPI exercise testing is easily performed and highly reproducible, it is well suited to clinical use in the diagnosis and documentation of intermittent claudication. Furthermore, since limb ischemia can be quantified, this method lends itself both to grading the severity of disease and to evaluating clinical progression of disease. It is suggested that such a quantitative approach to evaluation of intermittent claudication may allow refinement and extension of the indications for operative intervention in patients with intermittent claudication.
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PMID:Use of a transcutaneous PO2 regional perfusion index to quantify tissue perfusion in peripheral vascular disease. 683 Mar 39

Four cases of the popliteal artery entrapment syndrome including two with bilateral lesions are reported. All limbs of these patients showed classical arterial entrapment due to the anomalous course of the popliteal artery in relation to the medial head of the gastrocnemius muscle. All cases were diagnosed preoperatively, and computed tomography demonstrated apparent separation of the popliteal artery and vein at the site of the insertion of the gastrocnemius muscle. All patients complained of gradually progressive intermittent claudication except for one who revealed acute leg ischemia following long periods of driving and Japanese-style sitting. Surgical treatment resulted in complete recovery in all limbs. Pathological characteristics in the popliteal artery were: (1) the presence of longitudinal smooth muscle bundles in the medial coat adjacent to the gastrocnemius muscle, and (2) intimal thickening and/or thrombus formation adjacent to the medial condyle of the femur.
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PMID:Diagnostic and pathological considerations in the popliteal artery entrapment syndrome. 686 82

The mitochondrial volume densities (Vmit) of the different fiber types (type 1, type 2A, type 2B) were estimated in bilaterally obtained biopsies from 22 patients with unilateral intermittent claudication. These data, which were obtained from structurally intact fibers, were compared with clinical data from the same subject. In both the asymptomatic and symptomatic legs, Vmit 1 greater than Vmit 2A greater than Vmit 2B. Furthermore, Vmit 1 covariated with Vmit 2A and Vmit 2A with Vmit 2B in the asymptomatic legs (as in healthy subjects) but not in the symptomatic legs. Vmit 2 (mainly Vmit 2A) covariated with the age of the subjects in both legs. Vmit Tot was higher in the symptomatic legs than in the asymptomatic legs. This was mainly due to increase in the oxidative fibers, type 1 and type 2A. Usually, Vmit in the asymptomatic legs covariated significantly with the results of the functional tests (initial pain and maximum walking tolerance), while only Vmit 2A in the symptomatic legs showed such a correlation. However, the difference between the two legs concerning Vmit 1 was also correlated to the walking tolerance. Patients with high stenosis or occlusion showed higher Vmit Tot than did those with low obstacles. The results conclusively show that a fiber type-specific adaptation to ischemia occurs through an increase of mitochondrial content of oxidative fibers, which suggests that hypoxia may influence the control of synthesis or degradation of mitochondrial proteins.
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PMID:Intermittent claudication and muscle fiber fine structure: morphometric data on mitochondrial volumes. 692 64

The effect of chronic occlusive peripheral vascular disease (PVD) on the histochemistry and capillarity of the gastrocnemius muscle was studied in 129 biopsies taken from 93 subjects. Sixty-three patients underwent biopsy during surgical procedures, and data related to walking distance and ankle systolic pressure. Thirty biopsies taken from normal subjects post mortem served as a control group, and data were analyzed for fiber type distribution, fiber area, fiber type grouping, and fiber capillarity. Fiber type distribution did not alter significantly between the patients with PVD and the control group, but the mean fiber area of the type 1 fiber in male patients with intermittent claudication (IC) was reduced when compared to that in age-matched controls (4608 +/- 1181 mu 2, IC +/- 1 SD; 5795 +/- 1771 mu 2, controls +/- 1 SD) (P less than 0.05). When bilateral biopsies were taken from the gastrocnemii of patients with unilateral occlusions, the type 2 fibers in the diseased leg were significantly smaller than fibers of the control group (2821 +/- 953 mu 2, IC +/- 1 SD; 4318 +/- 1504 mu 2, controls +/- 1 SD) (P less than 0.02). Fiber type grouping, evidence of denervation and reinnervation of muscle, appeared to be more common in patients with more severe limb ischemia. Overall capillary numbers did not appear to alter with degree of ischemia, but fiber shrinkage appeared to compensate for any loss of capillaries in the more ischemic muscle. These data suggest that the limb of the untrained patient with IC does not adapt to ischemia by adjusting its exercise capacity but merely shows evidence of disuse. These adaptations suggest that there may be much to be gained by nonsurgical methods of treating IC.
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PMID:Ultrastructural and capillary adaptation of gastrocnemius muscle to occlusive peripheral vascular disease. 710 Nov 34

Blunt injuries to the abdominal aorta with initial survival are rare. Two cases of blunt aortic occlusion are reported: one with acute abdominal symptoms and leg ischemia and one with delayed intermittent claudication. The first patient died 9 days postinjury with possible sepsis and bronchopneumonia. The second presented with delayed symptoms 9 years postinjury: fibrous thickening of the intima, a dense, fibrous band around the aorta and left renal vein. After a Dacron graft from the descending thoracic aorta to the external iliac arteries the patient recovered and is employed full time.
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PMID:Aortic occlusion following blunt trauma of the abdomen. 721 99

Severe ischemic lesions were observed in 5 cases among women aged between 35 and 43 years taking the contraceptive pill over a period of 4 years. Three of these patients developed sudden severe ischemia of the lower limbs after the unrecognized appearance of intermittent claudication for periods of from 2 to 10 months, and amputation was necessary after various ineffective treatments. Recovery occurred in the two other patients, one of whom developed ischemia in the upper limb, the other in the lower limb, who were treated at an early stage. The young age of these women and the absence of atheroma were factors that suggested that the oral contraceptives, taken for periods of from 6 months to 4 years, were at least partially responsible for the lesions, and this hypothesis was supported by the discovery of anti-ethinyl estradiol antibodies in the serum. This was probably not the only causative factor, however, as all the patients were smokers. These cases demonstrate the danger of associating smoking with the taking of oral contraceptives, that the latter should be discontinued when signs suggestive of peripheral arterial insufficiency appear, and that urgent thrombectomy should be conducted in cases of severe ischemic lesions.
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PMID:[Acute ischemic lesions in young women taking oral contraceptives. A report on 5 cases (author's transl)]. 724 Sep 88

The treatment of intermittent claudication by physical training includes walk and more specific exercises stopped before ischemia. Progresses are followed each week by the measurement of walking distance, and recognised by the majority of the authors. Physical training has thus far proved to be one of the best non surgical treatment of intermittent claudication.
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PMID:[Treatment of intermittent claudication by physical training. Techniques and place of reeducation (author's transl)]. 728 7

During the past 20 years, 163 patients had 194 operations for obliterative arterial disease of the upper extremity. Of these, 68 had neurological symptoms primarily that were associated with arterial obstruction of the first portion of the subclavian artery. The remaining 95 patients had ischemic symptoms of the upper extremity, namely, intermittent claudication of the arm or ischemic necrosis of the fingers. There were 95 procedures performed on 90 patients with diminished or absent brachial blood pressures. There were 89 cervical sympathectomies performed on patients whose brachial pressures were equal to the contralateral arm. When sympathectomy was done, results were excellent in patients who had a rise in skin temperature confirmed preoperatively by reflex vasodilation studies. An aggressive approach with early diagnostic arteriography and appropriate surgical therapy is indicated in patients with ischemia to the upper extremity.
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PMID:Obliterative arterial disease of the upper extremity. 731 56

To test the hypothesis of a myofascial component in intermittent claudication, 56 male patients were studied. Calf blood flow, at rest and during postischemic and postexercise hyperemia, presence of trigger areas, and exercise tolerance were evaluated and compared. The results can be summarized as follows: The exercise tolerance is reduced when trigger areas are present in the calf muscles, and the more severe the trigger areas, the lower is the exercise tolerance. Trigger areas are more severe when the hyperemic flow is more reduced. The peak flow of reactive hyperemia is also correlated to work load. Pain in intermittent claudication is a complex phenomenon. According to the aforesaid results, the severity of limb ischemia and the presence of trigger areas in the calf appear to be the major factors. Besides the two reasons already known, a third is suggested to explain calf claudication: the elective location of trigger points in the gastrocnemius muscle.
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PMID:Fibrositic myofascial pain in intermittent claudication: significance of trigger areas in the calf. 736 34


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