The aetiology of vein graft strictures: a prospective marker study

In a prospective series of 74 femoro-popliteal vein grafts (34 in situ and 40 reversed), 22 strictures were identified by duplex scanning in 18 grafts (24.3%). Thirteen strictures were identified in 10 of 40 reversed grafts and 9 strictures were identified in 8 of 34 in situ grafts. Grafts were marked at operation using surgical clips at sites of all valves, tributaries, clamps and venotomies, since these have all been suggested as potential sources of graft strictures. These were prospectively studied as part of a detailed graft surveillance programme by intravenous digital subtraction angiography and duplex scanning. A total of 377 valves, 681 tributaries, 15 clamps and 2 venotomies were identified. Twenty-two strictures were detected in 18 grafts, an incidence of 24.3%, but only one lesions coincided with a specific marked area (a valve site). Duplex examination in 34 in situ grafts identified 10 residual valve cusps in seven grafts. In none of these was there any evidence of turbulence or flow disturbance, and none progressed to form a stricture. It is concluded that there is no correlation between valve sites, tributaries, clamp sites or residual valve cusps and the development of vein graft strictures.