[Venous bypass on the opposite side (Palma's operation). Preoperative evaluation. Technical variants. Indications and results].

Permanent obstruction of an iliac vein may produce serious consequences. Palma's operation of inter-femoral transposition of the internal saphenous vein on the opposite side, has permitted numerous improvements, but may lead to 30 p. 100 failures. Temporary arterial blood supply to the area increases the operative risk and requires a second stage operation for suppression of the fistula, but it maintains permeability of the by-pass, if correctly performed. The indications should thus be drawn up with circumspection and one may regret that such extensive venous lesions had not been prevented or treated actively as soon as they started to develop.