Utility of direct angiosome revascularization and runoff scores in predicting outcomes in patients undergoing revascularization for critical limb ischemia

Abstract

Both runoff scores and direct (DR) vs indirect revascularization (IR) according to pedal angiosomes have unclear impact on outcome for patients with critical limb ischemia (CLI). We compared DR vs IR and runoff scores in CLI patients undergoing infrapopliteal bypass for foot wounds. Patients who had tibial/pedal bypass for a foot/ankle wound from 2005-2011 were identified and operations classified as DR or IR based on wound location and bypass target. A blinded observer reviewed angiograms for an intact pedal arch and calculated standard Society for Vascular Surgery (single tibial) and modified (composite tibial) runoff scores. Comorbidities, wound characteristics, wound healing, major amputation, and overall survival were determined. A total of 106 limbs were revascularized in 97 patients; 54 limbs had DR and 52 had IR, although only 36% of wounds corresponded to a single, distinct angiosome. Wound characteristics and comorbidities were similar between groups. Mean standard (7.9 vs 7.2; P = .001) and modified (22.2 vs 20.0; P = .02) runoff scores were worse (higher number indicates worse runoff) in the IR vs DR groups; 33% had a complete pedal arch. Complete wound healing (78% vs 46%; P = .001) and time to complete healing (99 vs 195 days; P = .002) were superior with DR vs IR but were not influenced by runoff score, modified runoff score or presence of complete plantar arch. In multivariate models controlling for runoff score, DR remained a significant predictor for wound healing (odds ratio, 2.9; 95% confidence interval, 1.1-7.4; P = .028) and reduced healing time (hazard ratio, 2.1; 95% confidence interval, 1.2-3.7; P = .012). Mean amputation-free survival (75 vs 71 months for DR vs IR; P = .82) and median survival (36 vs 33 months DR vs IR; P = .22) were not different for DR vs IR. DR according to pedal angiosomes provides more efficient wound healing, but is possible in only one-half of the patients and does not affect amputation-free or overall survival. DR is associated with improved runoff scores, but current runoff scores have little clinical utility in predicting outcomes in CLI patients.