[Reoperations for early thromboses of femoropopliteal and tibial artery bypass. Apropos of 50 cases]

The mechanism of thrombosis early after subinguinal bypass and outcome after revision surgery have been rarely analyzed. Results are reported of revision surgery for early thrombosis in 50 cases (10% of subinguinal bypass operations during the same period). Initial indication in the 40 men and 9 women (mean age 66.9 +/- 1.74 (SEM) years), was severe chronic or acute ischemia in 82%. The 50 thrombosed bypasses included 40 femoropopliteal, 8 femorotibial and 2 short bypasses. The bypass was by saphenous in situ (21 times), an inversed saphenous (9 times), a mixed bypass (12 times) and a prosthesis (8 times). The distal arterial bed was evaluated as good in 50% of cases. Analysis of cause of thrombosis, of the operative procedure and of the time before surgery enabled a technical cause to be determined in 31 of the 50 cases. Corrective surgery produced 16 permeable bypasses and 34 definitive thromboses complicated by 21 amputations and a 10% mortality. Improved results were related to a venous bypass (p less than 0.05), to a time before operation of less than 24 hours (p less than 0.02) and to a good distal bed. The 1 year actuarial permeability for the 50 bypass operations was 35%. Mixed bypass procedures and technical problems during surgery appear to be the principal predisposing factors of early thrombosis. In this series, the preoperative distal pressure index and intraoperative flowmetric recordings were not reliable predictive elements.