Influence of postoperative anticoagulant treatment on patient survival after femoropopliteal vein bypass surgery.

To examine whether anticoagulants given after autologous saphenous bypass surgery influenced patient survival 119 patients who received such a graft for obliterative arterial disease were recruited for a controlled clinical trial. Patients were randomly assigned to start, in the second postoperative week, phenprocoumon (60 patients) or no treatment (59 patients). The median duration of survival for all patients was greater than 60 months, and the 75%-quartile was 39.0 (SE of the median 3.9) months. 10 patients died in the treated group and 20 in the control group. The treated group had a greater probability of survival (p less than 0.023, Breslow; p less than 0.043, Mantel). Graft occlusions occurred in 11 patients in the treatment group and in 17 controls. When these patients were excluded from the analysis, the difference in probability of survival between the two groups remained significant (p less than 0.009, Breslow; p less than 0.013, Mantel).