Long-term outcomes after autogenous versus synthetic lower extremity bypass in patients on hemodialysis

Abstract

Hemodialysis dependence confers unique physiologic conditions. Prior reports of outcomes after infrainguinal open bypass operations in patients on hemodialysis have been based on relatively small sample institutional series. In this study, we evaluate long-term outcomes after open bypass operations in a large contemporary population-based cohort of hemodialysis patients. We studied all hemodialysis patients who underwent infrainguinal open operation using autogenous versus prosthetic conduits in the United States Renal Data System between January 2007 and December2011. Univariate methods (χ2, analysis of variance) were used to compare the characteristics of the patient and type of bypass. Kaplan-Meier, univariate and multivariate logistic, and Cox regression analyses were used to evaluate 30-day postoperative outcomes as well as patency, limb salvage, and mortality in the long term. There were 9,739 (autogenous: 59%, prosthetic: 49%) infrainguinal open bypass operations performed in this cohort. Of these, 4,717 (48%) were femoral-popliteal, 3,321 (34%) were femoral-tibial, and 1,701 (18%) were popliteal-tibial bypasses. Bypass operations were performed most commonly for critical limb ischemia (72%). Primary patency was 18% for both types of conduits at 5years (P=.16). Comparing autogenous versus prosthetic conduits, primary-assisted patency was 23% vs 20% at 5years (P=.98), while secondary patency was 30% for both conduits at 5years (P=.05). Limb salvage was 35% vs 41% at 5years (P<.001). Multivariable analyses demonstrated greater patency (adjusted hazard ratio [aHR]: 1.16; 95% confidence interval, 1.05-1.28; P=.003) and limb salvage (aHR: 1.12; 95% confidence interval, 1.01-1.24; P=.03) for autogenous compared to prosthetic bypasses. The advantage conferred by autogenous conduits was most clinically relevant for femoral-tibial (aHR: 1.34; 95% confidence interval, 1.17-1.55; P<.001) and popliteal-tibial (aHR: 1.55; 95% confidence interval, 1.09-2.21; P=.014) configurations. This large study evaluated the long-term outcomes of open bypass operations in patients on hemodialysis. The data confirm the long-term benefits of autogenous conduits compared with prosthetic conduits in this high-risk population of patients, especially for the treatment of distal lesions. Individual patient life expectancy, availability of adequate autogenous conduit options, indication for operation, level of disease, as well as potential need for future options for additional access for dialysis should be taken into consideration when deciding to construct an open bypass in a hemodialysis patient.