Maximizing the use of autogenous vein using the in situ (valve incision) technique

Bypass grafting to vessels beyond the popliteal bifurcation is an established method for treating severe limb ischaemia. Failure rate is high, however, especially when prosthetic vascular substitutes have to be used. When left in situ, saphenous vein can be used down to much smaller diameters than would be possible with reversed vein. With this method, vein utilization of around 90% can be achieved with respective increases in patency and limb salvage. Our early results with 26 in situ grafts are presented. In two cases the presence of a suitable tributary of the saphenous vein allowed a 'bifurcated' or 'femorotibial' graft to be performed. All patients (17 males, nine females) were admitted with limb threatening ischaemia. Mean ankle pressure index was 0.29 (s.d. = 0.09), range 0.18-0.53. Average graft intra-operative flow rate measured 96 ml/min. Twenty grafts remain patent while six grafts have failed. In three of these failures, performed early in the series, the graft could not be made to function at the time of surgery. The mean postoperative ankle pressure index was 0.87 (s.d. = 0.19). Cumulative patency rate at 24 months is 74%. This rises to 83% if the three 'on table' failures are excluded. Five amputations were required; four as a result of graft failure and one despite a functioning graft. Four grafts clotted within 24 h but have remained patent following immediate thrombectomy. One patient required ligation of an arteriovenous fistula on the third postoperative day.