United Network for Organ Sharing's expanded criteria donors: is stratification useful?

The United Network for Organ Sharing (UNOS) Expanded Criteria Donor (ECD) system utilizes pre-transplant variables to identify deceased donor kidneys with an increased risk of graft loss. The aim of this study was to compare the ECD system with a quantitative approach, the deceased donor score (DDS), in predicting outcome after kidney transplantation. We retrospectively reviewed 49 111 deceased donor renal transplants from the UNOS database between 1984 and 2002. DDS: 0-39 points; ≥ 20 points defined as marginal. Recipient outcome variables were analyzed by ANOVA or Kaplan-Meier method. There was a 90% agreement between the DDS and ECD systems as predictors of renal function and graft survival. However, DDS identified ECD- kidneys (10.7%) with a significantly poorer outcome than expected (DDS 20-29 points, n = 5,252). Stratification of ECD+ kidneys identified a group with the poorest outcome (DDS ≥ 30 points). Predictability of early post-transplant events (i.e. need for hemodialysis, decline of serum creatinine and length of hospital stay) was also improved by DDS. DDS predicted outcome of deceased donor renal transplantation better than the ECD system. Knowledge obtained by stratification of deceased donor kidneys can allow for improved utilization of marginal kidneys which is not achieved by the UNOS ECD definition alone.