Impact of Renal Posttransplantation Amputation on Allograft Outcomes: A Study of United States Renal Data System

Background. The prevalence of renal posttransplantation amputation and its impact on allograft and patient survival have not been widely reported. Methods. We used an incident cohort of patients who underwent renal transplantation between June 2004 and September 2009. Amputation data were obtained using Medicare institutional claim forms. Baseline demographics and comorbidities, such as peripheral vascular disease (PVD), diabetes, ischemic heart disease, cerebrovascular disease, hypertension, and smoking, were captured. The chi-square and t tests were used for statistical associations. KaplanYMeier survival curves were plotted for renal allograft and patient survival. Independent associations between patient factors and amputation were examined using multivariable Cox regression analysis. Results. Of the 85,873 renal transplant recipients, 1062 patients had amputation. The prevalence of amputation was higher in those with PVD versus those without PVD at listing (5.6% vs. 1%; P= 0.0001). Mean allograft survival was 55.5 +/- 0.55 months in patients with amputation versus 60.6 +/- 0.06 months in patients without amputation (P=0.0001). All-cause mortality was higher in patients with amputation versus those without amputation (19.9% vs. 7.3%; P=0.0001). Mean allograft survival was 60.97 +/- 0.67 months in nonYAfrican Americans without amputation versus 55.7 +/- 0.65 months in nonYAfrican Americans with amputation. Allograft survival was 59.73 +/- 0.13 months in African Americans without amputation versus 54.9 +/- 1.06 months in African Americans with amputation. In patients with amputation, race did not have any impact. Infectious complications were noted in 39 patients leading to death. Conclusions. Amputation is associated with decreased allograft and patient survival. Early detection and preventive strategies for PVD may decrease amputation rate and improve survival.