PROSPECTIVE RANDOMIZED MULTICENTER COMPARISON OF INSITU AND REVERSED VEIN INFRAPOPLITEAL BYPASSES

We have performed a prospective, randomized, multicenter study to compare in situ and reversed vein grafts for long limb salvage bypasses from the proximal thigh to an infrapopliteal artery. Three hundred eighty-four patients required an infrapopliteal bypass for critical lower extremity ischemia. Of these, 259 were excluded because a short vein bypass was performed or because the vein was considered inadequate. The remaining 125 patients had a randomized vein bypass, 63 reversed, 62 in situ. The two groups were similar with regard to risk factors, indications, graft dimensions, and outflow. Secondary patency at 30 months was similar for both techniques: reversed 67% +/- 9% (+/-SE); in situ 69% +/- 8%. For veins less-than-or-equal-to 3.0 mm in minimum distended diameter 24-month patency rates were 61% +/- 22% for 12 in situ veins and 37% +/- 29% for 10 reversed veins (p > 0.05). Angiographic evaluation of failing grafts revealed lesions similar in type and frequency in both types of grafts. These included focal (in situ, n = 4; reversed, n = 7) and diffuse vein hyperplasia (in situ, n = 2; reversed, n = 1), and inflow and outflow stenoses (in situ, n = 4; reversed, n = 3). The incidence of would complications and the mortality rate were similar for the two groups. These data show no significant difference in overall patency rates for the two types of vein grafts at 2 1/2 years. Because of the poor preliminary patency of reversed vein grafts less-than-or-equal-to 3.0 mm in minimum distended diameter, we suggest the in situ method be used preferentially when such small veins are encountered. Thirty percent of patients requiring a long infrapopliteal bypass had no vein suitable for an in situ graft, although an ectopic vein bypass was feasible. Thus surgeons performing these operations should be adept at both procedures.