Amputation versus Free Flap: Long-Term Outcomes of Microsurgical Limb Salvage and Risk Factors for Amputation in the Diabetic Population

Abstract

BACKGROUND: Reconstructive microsurgery is an effective limb-saving option for nonhealing lower extremity wounds in diabetic patients. However, the ability to predict the future need for amputation is unclear. This article seeks to identify risk factors for amputation following microsurgical free tissue transfer in the diabetic lower extremity. METHODS: Diabetic patients undergoing lower extremity free flap surgery between August of 2011 and January of 2018 performed by a single surgeon were identified retrospectively. Patient comorbidities, reconstructive conditions and flap traits, microsurgical outcomes, and long-term outcomes were examined. Variables conferring risk for future amputation were examined by means of regression analysis. RESULTS: Sixty-four patients met the criteria. The overall immediate flap success rate was 94 percent (60 of 64). Long term, 50 patients (78.1 percent) underwent successful salvage, and 14 patients (21.9 percent) required major amputation. Acute flap loss resulted in four amputations, and delayed complications (hematoma, infection, recurrent nonhealing) resulted in 10 amputations. The average time to amputation was 5.6 months. Risk factors for amputation were end-stage renal disease (OR, 30.7; p = 0.0087), hindfoot wounds (OR, 4.6; p = 0.020), elevated hemoglobin A1C level greater than 8.4 percent (OR, 1.4; p = 0.05), and positive wound cultures (OR, 6.1; p = 0.003). CONCLUSIONS: Multiple comorbidities and poor glucose control were identified as risk factors for amputation after free flap limb salvage. However, successful limb preservation is possible. CLINICAL QUESTION/LEVEL OF EVIDENCE: Risk, III.