Infrapopliteal arterial bypass for limb salvage: increased patency and utilization of the saphenous vein used "in situ".

A prospective study of "in situ" saphenous vein has been made to determine its patency and utilization when used for arterial bypass distal to the popliteal artery. The valvular obstructions to arterial flow were removed by the method of valve incision developed by the authors. Of 316 consecutive "in situ" bypass procedures, 133 attempts were made to complete the procedure to the infrapopliteal level for limb salvage. One hundred and twenty-four of these were completed, to 43 peroneal, 40 posterior tibial, 25 anterior tibial, and 16 tibioperoneal arteries. At the level of its distal transection, the saphenous veins had diameters of 3.5 to 2.5 mm in 58 cases (45%). Only 7% of these procedures could not be completed without resorting to the use of excised vein segments. There were seven occlusions within 30 days (94% immediate patency rate). Cumulative patency rates by life-table analysis at 1, 2, and 3 years were 87%, 82%, and 72%, respectively. Neither the vein diameter nor the location of the distal anastomosis had any effect on these patency rates. In spite of the immediate failure rate of 15% to 30%, reversed autogenous saphenous vein is the present material of choice for infrapopliteal bypass. However, when the generally accepted minimum diameter of 4 mm is applied, at least 25% of these veins may not meet this criterion. These data show that the "in situ" method allows for both increased bypass patency and utilization of saphenous vein by permitting the consistent use of increased bypass patency and utilization of saphenous vein by permitting the consistent use of veins of 3.5 mm diameter or less. The summation of these improved utilization and patency rates has resulted in a greater number of functioning bypasses when compared to the present experience with reversed saphenous vein and/or nonautogenous substitutes in current use.