[Clinico-pathological aspects of the lower limb ischemia in chronic arterial occlusive disease]

Abstract

Arteriosclerosis obliterans (ASO) and Buerger's disease are representative arterial occlusive disease which causes chronic lower limb ischemia. In ASO, ischemia is produced by atherosclerotic stenosis and/or occlusion of major arterial trees mainly from the abdominal aorta to the femoral arteries, and in Buerger's disease, smaller arteries distal to the calf and the elbow are generally affected by non-specific panarteritis. Thrombotic occlusion at the affected vessels and proximal and/or distal progression of the secondary thrombosis often deteriorate leg ischemia. In chronic limb ischemia, microcirculation distal to affected vessels is also deteriorated by activation of white blood cells and platelets which induce vasoconstriction, injury of intimal cells, platelet aggregation, increased permeability, etc. Fontaine's classification of chronic limb ischemia based on clinical signs and symptoms is useful for grading severity of ischemia and selecting an optimal treatment. Recently, the concept of chronic critical limb ischemia is advocated, which is a condition that the limb amputation will be inevitable without restoration of blood flow. Diagnostic modalities for chronic arterial occlusion and assessment for severity of ischemia are outlined.