One hundred and thirty and patients were operated on with unilateral distal bypass procedures for critical ischemia. Fifty-one patients (39%) ended up with graft occlusion or required major amputation within six months after reconstruction. Two-year graft patency was 38%. These rather disappointing results may be partly ascribed to inadequate preoperative selection of patients. Logistic regression model was used to assess whether the independent variables age, gender, diabetes mellitus, smoking, ankle-brachial pressure index (ABI), type of graft, coronary heart disease (CHD), previous vascular operation and site of distal anastomosis were associated with the outcome amputation and graft occlusion six months after reconstruction. CHD, type of graft, ABI and the location of distal anastomosis were significantly associated with outcome. The odds for amputation or occlusion was 2.4 times higher in the CHD group, 4 times higher if the anastomosis was located to the peroneal artery and 2.6 times higher for synthetic grafts. The logistic regression model was statistical significant (p = 0.03). However, the model did not aid sufficiently in the prediction of outcome, since one third was erroneously classified as success or failure. Cox's proportional hazard regression was employed to estimate the influence of the independent variables on graft patency. Favorable patency was found for those with distal anastomosis located to the tibial arteries, the non-CHD group and for higher ABI values. There was a trend towards significance for better patency in the autogenous vein group (p = 0.06). Although combinations of risk factors usable for preoperative prediction of the likelihood of graft failure, appropriate selection models of patients suitable for distal bypass operation have to be improved, to minimize the number of failed procedures.
