Surveillance of Lower Extremity Bypass Grafts

Vascular laboratory surveillance of infrainguinal bypass graft function has evolved to a recommended standard of patient care. The rationale for testing is based on the progressive nature of atherosclerosis and the propensity of both autologous vein and prosthetic conduits to develop stenotic lesions that produce a low-flow state and result in graft thrombosis.

Infrainguinal vein bypasses, constructed by reversed, nonreversed, or in-situ grafting techniques, tend to form stenotic lesions within the conduit (70%) or at anastomotic sites (30%) during the first several months to years following implantation. These stenotic lesions have the histologic appearance of myointimal hyperplasia and are known to develop at sites of vein injury, form at valve sites, result from preexisting vein disease, or arise de novo in response to arterialization in the atherosclerotic environment ( Box 1 ).