Survival Benefit of En bloc Transplantation of Small Pediatric Kidneys in Children

BACKGROUND: En bloc transplantation of small pediatric kidneys in children may help expand the existing deceased donor pool; however, studies examining the long-term outcomes of en bloc transplantation in children are few.

METHODS: We used the Scientific Registry of Transplant Recipients to identify 149 pediatric en bloc recipients transplanted from 10/1/1987-12/31/2017. We used propensity scores to match 148 en bloc with 581 non-en bloc deceased donor recipients (matching variables: transplant age, gender, race, pretransplant dialysis, transplant center and year). We evaluated patient and graft survival using Kaplan-Meier and Fleming-Harrington weighted log-rank test, and examined survival benefit of en bloc transplantation versus remaining on the waitinglist using the sequential Cox approach. We divided the study period into three 10-year intervals to assess the effect of era on outcomes.

RESULTS: Compared with non-en bloc recipients, en bloc recipients had lower 1-year graft survival (78.9% vs. 88.9; p 0.007), however when stratified by transplant era, lower 1-year survival was only observed in the oldest era (1987-1997). En bloc recipients had superior 10-year patient (89.0% vs. 80.4%; p 0.04) and graft survival (51.6% vs. 39.9%; p 0.04) compared with non-en bloc recipients. After multivariate adjustment, en bloc transplantation was associated with superior patient survival compared with remaining on the waitinglist (aHR: 0.58; 95%CI: 0.36-0.95; p 0.03).

CONCLUSIONS: En bloc transplantation of small pediatric kidneys in children is associated with superior long-term patient and graft survival. The increased risk of 1-year graft loss among en bloc recipients only appeared in the oldest era.