Superiority of Pediatric En Bloc Renal Allografts Over Living Donor Kidneys: A Long-term Functional Study

Abstract

Background. Growing waiting list for kidney transplantation in the United States makes it imperative to expand donor pool to use of pediatric kidneys. Because en bloc pediatric kidneys double nephron numbers, it would be interesting to learn how they fare compared to living donor kidneys long term. Methods. Retrospective chart review was performed on all 72 pediatric en bloc and 75 live adult donor kidney recipients transplanted between January 1990 and December 2001. Long term graft function was assessed with glomerular filtration rate (GFR) using the abbreviated modification of diet in renal disease (MDRD) formula. Results. Pediatric donor was 16.9±11.2 months old and weighed 10.7±3.8 kg. Nine en bloc kidneys thrombosed at a mean of 4.2 days posttransplantation. Proteinuria was detected later posttransplantation in en bloc group (45.6±33.6 months vs. 23.4±16.3 months, P=0.002). Pediatric en bloc recipients had significantly higher GFR up to 8 years posttransplantation. One-year graft survival was significantly better in live donor group (93.3% vs. 81.9%, P=0.041) but five-year graft survival rates were similar (86.7% vs. 76.3%, P=0.125). One-year and five-year patient survival rates were similar between en bloc and live donor groups (97.3% vs. 98.6%, P=0.585 and 94.6% vs. 93.0%, P=0.688, respectively). Conclusion. Early postoperative graft thrombosis remain a challenge with pediatric en bloc renal transplants, but once the allografts survive early postoperative course, they provide better long-term function than living donor kidney transplants. In order to alleviate burden on waiting list, pediatric en bloc kidneys should be transplanted more often when available.