The effect of center volume on pancreas transplant outcomes

BACKGROUND: Caseload often correlates with improved outcomes for several surgical procedures, including solid organ transplantation. Given the unique nature of pancreas transplantation and large variation in transplant center volumes, this study aims to determine whether center volume affects patient and graft survival after pancreas transplantation. METHODS: Registry data on all forms of whole organ pancreas transplants performed between 1995 and 2000 were obtained from the United Network for Organ Sharing. Patient and graft survival rates were followed until 2002. Center volume then was categorized as: low (< 10/year), medium (10-20/year), high (21-50/year), and very high (< 50/year). Cox proportional hazard regression models were developed to evaluate factors affecting pancreas transplant outcomes. RESULTS: Very-high-volume centers were more likely to do pancreas after kidney transplant, pancreas transplant alone, pancreas with kidney transplant, and repeat transplants, while other centers more frequently performed simultaneous pancreas-kidney transplants (P < .001). Very-high-volume centers were more likely to transplant older recipients and less likely to transplant minority or Medicaid patients. Low-volume centers tended to accept pancreatic allografts from younger donors and had the longest waiting times. In models adjusting for differences in patient population, there were no differences in patient survival. However, low-volume centers had a slightly increased risk of graft loss compared to other centers. Early graft loss was similar among all centers, but medium-volume centers were at increased risk for late graft loss. CONCLUSIONS: Low center volume is not associated with increased mortality after pancreas transplantation. Other factors appear to be more important than center volume in determining pancreas transplant outcomes.