Is the use of suboptimal saphenous veins justifiable for limb salvage?

In situ saphenous vein bypass (ISSV) techniques are preferable when the "ta rget vessel" for arterial reconstruction is below the knee. There is no min imally acceptable vein; however, it must be large enough to generate a phys iologic increase in ankle pressure following bypass. This retrospective cha rt review sought to determine success rates for limb salvage and long-term graft patency in individuals with "less than optimal" saphenous veins. Over a 24-month period, 76 below-the-knee ISSV bypasses were performed and 17 v eins were described as "suboptimal." Of those, three had evidence of prior thrombophlebitis, one had severe varicose changes throughout the graft leng th, and two were too small to be used for reconstruction. Of the 11 small s aphenous veins used, the smallest diameter measured after establishment of arterial flow ranged from 0.9 to 1.6 mm (mean=1.2). Target vessels included the below-the-knee popliteal artery (n=one), posterior tibial artery (n=tw o), peroneal artery (n=four), anterior tibial artery (n=two), and the dorsa lis pedis artery (n=two). Following arterial anastomosis, a 15% or greater increase in ankle-brachial index was achieved in all cases. Limb salvage wa s achieved in eight of 10 limbs. However, amputation was required in three patients and one died secondary to chronic renal failure. Follow-up ranged from 3 to 24 months (mean=13). Four bypasses thrombosed despite aggressive surveillance, two had multisegmental graft stenoses requiring revision, and five remained patent (mean follow-up: 9.6 months). Short-term patency was satisfactory and immediate limb salvage was achieved. However, long-term li mb salvage was not improved. On the basis of these results, the authors wou ld not recommend the use of saphenous veins less than 2 mm minimum diameter for ISSV bypass.