Diagnostic and pathological considerations in the popliteal artery entrapment syndrome.

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.