Risk factors for major limb amputations in diabetic foot gangrene patients.

We analyzed the clinical picture of diabetic foot lesion patients to investigate the risk factors for major limb amputations. The subjects were 210 diabetic foot lesion patients treated at our department over the past 9 years. The mean follow-up period was 604.5 [standard deviation (S.D.) 451.2] days with a median value of 492 days. There were 113 men and 97 women. By the final follow-up day, 18 underwent bypass surgeries (9%) and 13 skin grafts (6%), while 110 patients (52%) finally required limb amputation. The breakdown was 45 major amputations above or below the knee and 65 minor amputations of the toes or metatarsals. The outcomes of the major amputations were retrospectively analyzed by group. The blood glucose control was poor in all 45 major amputees, and their mean HbA1c (8.80%) was higher than that in the minor or non-amputation group (7.79%, P = 0.035). In the major amputation group, two patients had loss of vision due to retinopathy, and 30 patients received long-term hemodialysis due to nephropathy. The rate of arteriosclerosis obliterans (ASO) was higher in the major amputation group than in the minor or non-amputation group, and arteriography showed significantly high rates of multiple stenosis. Multivariate analysis of these results by the proportional hazard model showed that ASO with multiple stenosis (hazard ratio 3.23, 95% CI: 1.12-5.10), hemodialysis (2.14, 95% CI: 1.17-3.44), and HbA1c (1.20, 95% CI: 1.03-1.41) were independent risk factors for major amputation. The 3-year survival rate was 24.1% in the major amputation group and 93.0% in the minor or non-amputation group, and the life expectancy was significantly lower for the major amputees than the minor or non-amputees (P<0.0001). Together with early detection and treatment of foot lesions, good blood glucose control and early management of systemic complications such as nephropathy and arteriosclerosis are considered important to avoid major amputations.