The non-reversed vein femoro-distal bypass graft: a modification of the standard in situ technique.

The results of 85 in situ vein femoro-distal bypass grafts using a modified technique where the vein was completely mobilised but left "non-reversed" have been reviewed with particular regard to risk factors and complications. The distal anastomosis was to the infrageniculate popliteal artery in 55% and to the tibioperoneal trunk or a single calf vessel in the rest. Arteriographic run-off was by a single vessel in 42%. The primary failure rate at 1 month was 20% and the secondary failure rate 9%; the majority of early failures being due to missed technical errors despite the use of a pulse volume recorder. The cumulative secondary patency rate at 1 and 2 years was 77% and 72%; limb salvage 85% and 77%; and patient survival 89% and 83% respectively. The only significant risk factors were the level of the distal anastomosis and the run-off (P = 0.002 and 0.03 respectively). Complete mobilisation of the vein allows a tension free proximal anastomosis to the common femoral artery and avoids the risk of arteriovenous fistulae. A high vein utilisation rate of 93% was achieved by using a small 2.5 mm Hall valvulotome. Although there was a trend towards lower patency rates in veins with a minimum diameter less than 4 mm the results are still superior to PTFE. Compared to reversed vein the in situ technique has a better utilisation rate and the long-term patency rates are at least as good if not better. Improved methods of haemodynamic assessment during reconstruction to reduce technical errors may be the key to better early patency rates.