POPLITEAL VEIN COMPRESSION DUE TO POPLITEAL ARTERY ANEURYSM - EFFECTSOF ANEURYSM SIZE

Unlike the venous compression associated with larger popliteal artery aneurysms, which frequently is associated with deep vein thrombosis, t he venous compression caused by the moderate sized (greater than 2 cm and less than 3 cm) aneurysms in the reported cases is not associated with thrombosis. The extrinsic compressive effect of these moderate si zed popliteal artery aneurysms on the adjacent vein is shown to vary w ith the patient's leg position. Three of the four patients with unilat eral leg swelling discussed here had bilateral popliteal artery aneury sms. In these cases, the contralateral leg had a small popliteal aneur ysm (less than 2 cm) and no leg swelling was present. The cases sugges t that popliteal artery aneurysm size is an important factor in determ ining the type of venous obstruction that results from the extrinsic c ompression of the ipsilateral popliteal vein. The described phenomenon of a popliteal artery aneurysm having the effect of restricting flow in the ipsilateral popliteal vein must be included as a differential d iagnosis among the causes of unilateral leg swelling in the absence of deep vein thrombosis.