A personal experience with the influence of diabetes and other factors on the outcome of infrainguinal bypass grafts for occlusive disease

Objective: To investigate the influence of diabetes mellitus and other factors on the outcome of all infrainguinal bypass grafts performed for occlusive disease by a single surgeon at a tertiary referral center. Methods: The series includes 650 operations in 412 men and 238 women with median ages of 65 and 69 years, respectively. Critical ischemia was the indication for most procedures (n = 553, 85%), but 97 (15%) were done for claudication alone. Nearly half (n = 312, 48%) of the patients were diabetic, and 195 (30%) required insulin. All-autogenous vein was used for 389 grafts (60%). Synthetic or composite materials were employed for the remaining 261 grafts, 91 (35%) of which were entirely above the knee. Perioperative data were recorded contemporaneously and were supplemented by reviewing 558 of the 565 medical records and the Social Security Death Index. Survival, graft patency, and limb salvage were analyzed using logistic regression, Kaplan-Meier estimates and proportional hazards models. Results: Diabetics were more likely to have critical preoperative limb ischemia (P < .001), elevated serum creatinine (P = .003) or a history of previous coronary intervention (P = .015), lower extremity revascularization (P < .001) or minor amputations (P = .002). The operative mortality rate was 4.8%, and there were 81 graft occlusions (12%) and 49 major amputations (7.5%) during the index hospital admission. Patency was immediately restored in 46 of the 81 occluded grafts, but their secondary patency rates were only 62 +/- 16% at 1 year and 26 +/- 18% at 5 years. Insulin-dependent diabetes was associated with a higher incidence of early amputation (odds ratio, 2.6; 95% confidence interval [CI], 1.4-4.8; P = .004). Overall survival was 52 +/- 4% at 5 years and 25 +/- 5% at 10 years, and there were 175 late graft occlusions (27%), a total of 198 related reoperations and 107 late amputations (16%). The risks for further occlusion and/or major amputation after three or more graft revisions were 65% and 71%, respectively. Insulin-dependent diabetes also was associated with higher late mortality (hazard ratio [HR], 1.5; 95% CI, 1.2-1.8; P = .001) and amputation rates (HR, 1.5; 95% CI, 1.0-2.1; P = .026), but other independent variables like age, elevated serum creatinine, critical preoperative ischemia, synthetic conduits, and previous ipsilateral bypass had at least as much influence as diabetes on survival, graft failure or limb loss. Conclusions. Diabetes was one of several factors influencing survival and limb preservation, but it did not adversely affect graft patency. The number of graft revisions was an important predictor of further occlusion or amputation.