PC156. Initial Open versus Endovascular Treatment and Subsequent Limb Loss After Primary Minor Amputation

Abstract

Studies of major amputation after initial minor amputation are limited with rates of subsequent major amputation ranging from 14% to 34% with a limited understanding for associated comorbidities and time to subsequent amputation. We sought to determine major amputation rates for patients that undergo initial minor amputation and determine which factors are associated with limb preservation with open vs endovascular treatment. Using statewide longitudinal data we identified patients with peripheral artery disease (PAD), diabetes mellitus (DM), and combined PAD/DM with a lower extremity ulcer that underwent minor amputation from 2005 to 2013. We determined rates of subsequent major amputation, time to amputation, and performed Cox proportional hazards modeling to study which factors affect a patients risk of subsequent major amputation including initial treatment with open vs endovascular therapy. From 2005 to 2013, 11,597 patients (DM, 4254; PAD, 2142; PD, 5201) with ulcers underwent minor amputation throughout the state. The rate of subsequent amputation was highest in patients with PAD/DM (23% vs DM, 17%, PAD, 17%; P = NS). The rate of subsequent minor amputation was 16% in the PAD/DM group versus 15.2% in PAD and 12.2% in patients with DM. Patients with PAD/DM had the highest rate of subsequent major amputation (6.3 % vs DM, 5.2%, PAD, 2.1%, p=NS). The median time to major amputation was lowest in patients with PAD (8.5 months vs DM 14 months, PAD 13 months; P = NS). For patients who underwent revascularization, there was no difference in risk of subsequent major amputation for patients that underwent initial open revascularization vs endovascular therapy (hazard ratio, 0.92; 95% confidence interval, 0.92-1.04). There was also no difference in time to subsequent major amputation between open and endovascular treatment (9.8 vs 8.7 months; P = S). In multivariable analysis, patients who could be treated completely in the outpatient setting were less likely to undergo amputation (hazard ratio, 0.7; 95% confidence interval, 0.5-0.99) compared with those who required hospitalization or presented to the emergency room. Patients with ischemic ulcers and diabetes are at the highest risk for subsequent major and minor amputation, with most occurring within a year of the initial minor amputation. Initial endovascular treatment did not increase the risk of subsequent major amputation compared with open and there was no difference in time to amputation indicating the endovascular first approach may be reasonable for patients with critical limb ischemia.