Pediatric en bloc kidney transplants appear to provide better outcomes than adult cadaveric transplants, but how do they compare with living donor transplants?OBJECTIVE
To compare the long-term function of pediatric en bloc renal allografts and adult living donor allografts.DESIGN AND INTERVENTION
The charts of patients who received a pediatric en bloc or adult living donor renal allograft at Allegheny General Hospital, Pittsburgh, PA, between January 1990 and December 2001 were retrospectively reviewed. Glomerular filtration rate (GFR) was calculated 6 months after transplantation and every year subsequently for 8 years of follow-up, using the MDRD equation.OUTCOME MEASURES
The main endpoints were graft and patient survival at 1 year and 5 years after transplantation, GFR, and dipstick proteinuria.RESULTS
Male:female ratio, age, etiology of end-stage renal disease and immunosuppressive regimens were similar in the 72 patients who received en bloc kidneys and the 75 who received living donor kidneys. The frequency of acute rejection was similar in the two groups. Arterial or venous thrombosis occurred in 9 en bloc allografts (12.5%; at 4.2 days following transplantation on average), but in none of the living donor grafts. The kidneys that thrombosed tended to come from younger donors than those that did not (mean ages 11.7 months vs 18.3 months; P = 0.044). One-year graft survival was significantly higher among recipients of living donor kidneys than among recipients of en bloc kidneys (93.3% vs 81.9%; P = 0.041). Graft survival remained higher at 5 years in those who received living donor kidneys than in those who received en bloc allografts (86.7% vs 76.3%), although the difference did not reach statistical significance. Patient survival was not significantly different between the groups at 1 year or 5 years. Patients who received living donor kidneys had significantly lower GFR at every time point than those who received en bloc kidneys (P<0.001 for post-transplantation years 1-7; P = 0.017 at 8 years). Unlike the living donor group, the en bloc group also showed a gradual increase in GFR up to 5 years after transplantation. The incidence and magnitude of proteinuria was not significantly different between the groups, although the recipients of living donor kidneys developed proteinuria sooner after transplantation than the recipients of en bloc kidneys (mean 23.4 months vs 45.6 months; P = 0.002). In the living donor kidney group, BMI was higher among protein-uric patients than among nonproteinuric patients (27.6 vs 24.7; P = 0.049); however, this trend did not persist in the en bloc kidney group. Five of the patients who received en bloc kidneys and one patient in the living donor group required angioplasty for renal artery stenosis. Other complications included hydronephrosis and lymphoceles.CONCLUSION
Pediatric en bloc renal allografts are often associated with early post-transplantation thrombosis, but can provide excellent long-term graft function compared with adult living donor allografts.