IMPAIRED PERIPHERAL VASODILATION IN ISCHEMIC AND NONISCHEMIC LIMBS OFPATIENTS WITH UNILATERAL ARTERIOSCLEROSIS OBLITERANS - EFFECT OF REVASCULARIZATION ON LEG HEMODYNAMICS

Limb vessel vasodilation plays an important role in the regulation of skeletal muscle blood flow during exercise. However, little documentat ion is available that describes the vasodilatory response of periphera l vessels in patients with arteriosclerosis obliterans (ASO). This stu dy investigates possible impairment of basal blood flow and response i n ischemic and nonischemic legs of patients with ASO, and the effect o f revascularization on leg hemodynamics. Basal calf blood flow and rea ctive hyperemic response to femoral occlusion were measured plethysmog raphically in 20 patients with unilateral ASO (20 stenotic legs and 20 nonstenotic legs) and eight healthy subjects (eight control legs). Ei ght stenotic legs underwent percutaneous transluminal angioplasty or s urgical revascularization. Basal calf blood flow and peak hyperemic fl ow was significantly lower in stenotic and nonstenotic legs than in co ntrol legs. After revascularization, basal flow was unchanged in steno tic legs but elevated in nonstenotic legs (from 2.5 +/-0.3 to 3.4 +/-0 .4 mL/min/dL tissue, p<0.01). Peak flow in both legs was significantly elevated (stenotic legs, from 12.8 +/- 1.9 to 17.6 +/- 1.6 mL/min/dL tissue,p<0.01; nonstenotic legs, from 14.3 +/- 1.0 to 20.0 +/- 1.6 mL/ min/dL tissue, p<0.01), although still below control values. Basal blo od flow and maximum vasodilatory response of resistance vessels are im paired irrespective of the side of conduit vessel involvement. The vas cular response of the nonstenotic side is significantly enhanced after revascularization of the contralateral stenotic lesions. These sugges t that neural or circulating vasoacting factor(s) originating from the stenotic Limb may contribute to peripheral circulatory disturbance in claudicants.