[Late results and clinicopathological study of vein graft failure in infrainguinal arterial reconstruction].

Long-term follow-up study of 79 infrainguinal arterial bypasses with autogenous vein graft in 62 patients was undertaken to clarify the cause of late graft occlusion. Thirty grafts failed during the follow-up period, including 7 early and 23 late occlusions. The overall cumulative patency rate at 5 years was 58.6%. The analysis of angiograms of 33 limbs revealed the long-term morphological changes which included 1 occlusion of the femoral artery proximal to the vein bypass, 8 graft stenosis, and 5 atherosclerotic progressions of the outflow tract. The causes of 8 graft stenoses consisted of 5 anastomotic intimal hyperplasia (ANIH), 2 atherosclerotic changes, and 1 external compression of the graft by tendons. All of four histologically examined stenosed anastomoses had marked peri-anastomotic fibrosis, which was suspected to be caused by extensive circumferential dissection of the host artery at the initial operation. In 3 stenosed anastomoses with arteriosclerosis obliterans, the luminal diameter was the narrowest at the arterial side with intimal hyperplasia over remnant atheromatous lesion. In conclusion, ANIH is the most influential cause of graft occlusion, and perianastomotic local factors such as initial anastomotic deformity, periarterial fibrosis, and remnant arterial lesion at anastomosis, revealed to have much influence on the cause of ANIH.