Iatrogenic entrapment of femoropopliteal saphenous vein bypass grafts by the gastrocnemius muscle.

Two patients are described in whom saphenous vein grafts placed distal to the knee joint were "entrapped" by the medial gastrocnemius tendon. In one, the superficial position of the graft was detected by postoperative angiography. In the other, a true aneurysm of the vein graft developed over a 3 year period. The similarity between the iatrogenic and congenital forms of the popliteal entrapment syndrome is noted.