Evaluating the survival benefit of kidney retransplantation.

Background: The magnitude of the survival benefit associated with kidney retransplantation has not been well studied.
Methods: Using data from the Canadian Organ Replacement Register (CORR), we studied patients (n=3,067) initiating renal replacement therapy during 1981-1998 who had received a transplant and experienced graft failure (GF). Such patients were followed until death, loss to follow-up or the end of the observation period (December 31, 1998). Using Cox regression, we estimated the post-GF covariate-adjusted hazard ratio (HR) for retransplant versus dialysis, and determined whether the contrast differed across patient subgroups. Through nonproportional hazards models, we also examine patterns in the retransplant/dialysis HR with time following retransplant.
Results: Overall, retransplantation is associated with a covariate-adjusted 50% reduction in mortality, relative to remaining on dialysis (HR=0.50; P<0.0001). This benefit is most pronounced in the 18- to 59-year age group. Retransplanted patients were at significantly higher risk of death relative to patients on dialysis only during the first month posttransplant (HR=1.66; P=0.047), and experienced significantly reduced mortality thereafter.
Conclusions: Following primary graft failure, retransplantation is associated with significantly reduced mortality rates among Canadian end-stage renal disease patients. Further study should be undertaken to assess the applicability of our findings to other patient populations.