Entrapment of below-the-knee bypass grafts.

A case is presented in which a below-the-knee saphenous vein bypass graft was compressed between the sartorius and the semimembranosis, semitendinosis, and gracilis muscles. Angiography and noninvasive Doppler showed occlusion with leg extension but no obstruction to flow with flexion. Recognition of this entrapment syndrome and its prompt correction can preserve patency of the graft.