Impaired Peripheral Vasodilation in Ischemic and Nonischemic Limbs of Patients 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 documentation is available that describes the vasodilatory response of peripheral vessels in patients with arteriosclerosis obliterans (ASO). This study investigates possible impairment of basal blood flow and response in ischemic and nonischemic legs of patients with ASO, and the effect of revascularization on leg hemodynamics. Basal calf blood flow and reactive hyperemic response to femoral occlusion were measured plethysmographically in 20 patients with unilateral ASO (20 stenotic legs and 20 nonstenotic legs) and eight healthy subjects (eight control legs). Eight stenotic legs underwent percutaneous transluminal angioplasty or surgical revascularization. Basal calf blood flow and peak hyperemic flow was significantly lower in stenotic and nonstenotic legs than in control legs. After revascularization, basal flow was unchanged in stenotic 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 blood flow and maximum vasodilatory response of resistance vessels are impaired irrespective of the side of conduit vessel involvement. The vascular response of the nonstenotic side is significantly enhanced after revascularization of the contralateral stenotic lesions. These suggest that neural or circulating vasoacting factor(s) originating from the stenotic Limb may contribute to peripheral circulatory disturbance in claudicants.