Maximizing Utilization in Pancreas Transplantation: Phenotypic Characteristics Differentiating Aggressive From Nonaggressive Transplant Centers

Background: Maximizing pancreas utilization requires a balance between judicious donor selection and transplant center aggressiveness. We sought to determine how such aggressiveness affects transplant outcomes. Methods: Using the Scientific Registry of Transplant Recipients, we studied 28 487 deceased-donor adult pancreas transplants. Donor and recipient demographic factors indicative of aggressiveness were used to score center aggressiveness. We compared outcomes of low (> 1 SD below mean), medium (± 1 SD from mean), and high (> 1 SD above mean) aggressiveness centers using bivariate and multivariable regressions. Results: Donor and recipient aggressiveness demonstrated a roughly linear relationship (R² = 0.20). Center volume correlated moderately with donor (r_s = 0.433) and recipient (r_s = 0.270) aggressiveness. In bivariate analysis, there was little impact of donor selection aggressiveness on graft survival. Further, for simultaneous pancreas and kidney transplants, centers with greater recipient aggressiveness selection had better graft survival. High-volume centers had better graft survival than low-volume centers. In multivariable analysis, donor aggressiveness did not have an effect on graft survival, whereas graft survival for medium (hazard ratio [HR], 0.66, 95% confidence interval [95% CI], 0.53-0.83) and high (HR, 0.67; CI, 0.51-0.86) recipient aggressiveness performed better than low-aggressiveness centers. There was a clear volume effect, with high-volume centers (>20 transplants/year; HR, 0.69; CI, 0.61-0.79) performing better than low-volume centers. Conclusions: Center practice patterns using higher-risk donors and recipients did not negatively affect outcomes. This effect is likely mediated through efficiencies gained with the increased transplant volumes at these centers.