PROXIMAL-TO-DISTAL VARIABILITY OF GREATER SAPHENOUS-VEIN DIAMETER ANDFREQUENCY-DISTRIBUTION OF SIDE BRANCHES AS AN INHERENT PROBLEM OF INFRAINGUINAL ARTERIAL BYPASSES IN-SITU

The greater saphenous vein is still the best material for infrainguina l arterial bypasses, particularly if they have an infrapopliteal dista l anastomosis. Although a lot of advantages have been presumed for the in-situ bypass, the reported results are not significantly better tha n with the reversed technique. To find some additional explanations, w e studied post mortem the anatomy of 20 greater saphenous veins with r egard to the diameter and the number of side branches and compared the results with 10 phlebographies. A minimal diameter (2.6 mm) and a max imum of side branches and venous valves were found at the proximal cal f. Furthermore, this region was characterized by a lot of anatomic var iants such as double systems (25%) or cross over variants (5%). These findings are surgically relevant and may reduce the bypass patency: 1. there is an increased hemodynamic resistance in longer bypasses, 2. t he small diameter (particularly if smaller than 2 mm) means a risk for the patency of the distal anastomosis, 3. the high frequency of side branches requires a comparable exposition of the GSV as for the revers ed technique, 4. the introduction of the valvulotome from distally may overstimate the proximal diameter and underestimate the frequency of variants and may therefore cause significant endothelial damages or ev en perforation.