Transplantation of single and paired pediatric kidneys into adult recipients

Background: The transplantation of kidneys from cadaveric donors ≤ 5 years of age into adult recipients is controversial. The large disparity between donor renal mass and recipient body mass is feared to be problematic. Controversy also exists whether to transplant kidneys from these young donors individually or as a pair into a single recipient. Study Design: We retrospectively reviewed our experience from January 1991 to January 1995 with 22 adult renal transplantations using kidneys from cadaveric donors ≤ 5 years of age. Ten patients received single allografts. Twelve received organs paired en bloc. Fifty-two adult recipients from cadaveric donors aged 18-55 years served as controls. All patients received cyclosporine-based immunosuppression. Recipient characteristics did not differ significantly between the groups. Results: Actuarial patient and graft survival rates were similar for the two groups. The incidence of urinary complications was higher in the recipients of pediatric kidneys than in the adult-donor group (18.2% versus 3.8%, respectively, p = not significant). No grafts were lost from urinary complications. Renal function, as determined by the calculated creatinine clearance, was significantly greater in the pediatric group (76.1 ± 4.0 versus 61.4 ± 23.2 mL/min, p = 0.035) by 6 months after transplantation. Recipients of paired pediatric kidneys initially had better renal function (63.9 ± 21.4 mL/min) than those receiving single pediatric kidneys (3.8.2 ± 11.6 mL/min) (p = 0.004), but by 6 months, no significant difference existed. At 2 years, renal function in the pediatric-donor group remained significantly better than in the adult-donor group. Hematocrit levels as a measure of erythropoiesis were similar for single pediatric, paired pediatric, and adult-donor recipients. Conclusions: Kidneys from cadaveric donors ≤ 5 years of age are suitable for transplantation into adults. Pediatric kidneys provide excellent renal function despite an initially tremendous disparity between renal mass and recipient body mass. Rapid true renal growth probably occurs. No appreciable advantage is achieved by using two pediatric kidneys for a single recipient.