Duplex imaging of in situ saphenous vein bypass grafts and late failure reduction

Duplex ultrasonic scanning was applied prospectively to 20 consecutive cases of in situ saphenous vein infrainguinal bypass 1, 3, 6, and 12 months postoperatively. All 20 (100 percent) and 17 of 19 (90 percent) of the proximal and distal anastomoses, respectively, could be imaged satisfactorily. Graft velocity ranged from 30 to 100 cm/s. Of three grafts with low velocity, one had impending graft failure and two had inherently low velocity but remained patent. Five defects in three grafts were detected. In three cases, intervention prevented graft failure. The primary patency rate was 80 percent, but was improved to 95 percent as a result of graft surveillance and simple revisions. Duplex scanning is a superior method for postoperative in situ saphenous vein bypass surveillance. We recommend that patients be studied 1 month postoperatively and every 3 to 6 months thereafter.