Clinical, hemodynamic, and anatomic predictors of long-term outcome of lower extremity venovenous bypasses

Abstract

Forty-three patients, 24 with crossover femoral saphenous vein bypasses and 19 with saphenopopliteal vein bypasses, were observed for a mean of 5.5 years. All underwent preoperative and sequential postoperative clinical, hemodynamic and foot venous pressure measurement, and anatomic evaluations (duplex and venography). Seventy-one percent of patients undergoing crossover femoral saphenous vein bypasses and 74% of patients undergoing saphenopopliteal vein bypasses had an abnormal preoperative maximum venous outflow, in contrast to 4% and 11% after operation ( p = 0.0183). The mean immediate postoperative maximum venous outflow improvement for patients having crossover femoral saphenous vein bypasses and those having saphenopopliteal vein bypasses was 16 and 17 ml, respectively, and the mean late improvement was 19 and 27 ml, respectively. Ninety percent of the patients undergoing crossover femoral vein bypasses and those having saphenopopliteal vein bypasses had abnormal foot venous pressures in contrast to 18% and 22% after operation. The final clinical outcomes (over 1 year) for both patients having the crossover saphenous vein bypasses and those having saphenopopliteal vein bypasses, respectively, were significant improvement (+3 and +2), 63% and 58%; significant worsening (−2), 4% and 5%. Eighty-eight percent of patients undergoing crossover femoral saphenous vein bypasses and 79% of patients undergoing saphenopopliteal vein bypasses with abnormal preoperative maximum venous outflow measurements had significant clinical improvement. In contrast, 86% of patients undergoing crossover femoral saphenous vein bypasses and 80% of patients undergoing saphenopopliteal vein bypasses with normal preoperative maximum venous outflow had no improvement. Seventy-seven percent of patients having saphenopopliteal vein bypasses and a normal venous refill time had significant improvement, in contrast to 17% for patients with an abnormal venous refill time (<10 sec). Sixty-seven percent of patients undergoing crossover femoral saphenous vein bypasses and 78% of patients undergoing saphenopopliteal vein bypasses with abnormal foot venous pressure measurements had significant improvement. The cumulative 7-year patency was 75% for patients having crossover femoral saphenous vein bypasses and 56% for those having saphenopopliteal vein bypasses. The operative mortality rate was 0% for both procedures, and the complication rate was 4% and 10%, respectively. The most important preoperative variables that correlated with a good outcome were a low preoperative maximum venous outflow, venous refill time >10 sec, and venous claudication and iliac vein compression. Patients with a normal maximum venous outflow measurement and severe venous reflux should not be candidates for these bypasses.