Background: The effect of the pre-emptive re-transplant, and of inter-transplant waiting time generally, on graft and recipient survival is not well established.
Methods: Analysis of the United States Renal Data System (USRDS) data (1/1/90 through 12/31/00; n = 92,844) was performed. Cox regression was used to analyse time to event, with an additional analysis to stratify by transplant era.
Results: Having a prior transplant, as well as the total number of transplants, was related to an increased risk of graft failure [hazard ratio (HR) 1.24, P<0.001 for history of prior transplant; HR 1.35 per transplant, P<0.001], but not to recipient death. The time waiting for re-transplant slightly worsened the risk for recipient mortality in the entire patient population and in the recipients of single re-transplant (HR 1.003 and 1.004 per month respectively, P<0.001), and for graft failure only in recipients of single re-transplant (HR 1.001 per month, P<0.05). Pre-emptive re-transplant (dialysis-free re-transplant or transplant within 6 days of last graft failure) increased the risk of graft failure (HR 1.36, P<0.001) and did not have any statistically significant effect on recipient survival. The longer duration of prior graft survival but not the type of the graft (living vs deceased) had protective effect on the consecutive graft and recipient survival.
Conclusions: With the potential caveats associated with retrospective data analysis, these results suggest that pre-emptive re-transplantation is associated with increased risk of graft failure, while longer time on dialysis in between transplants is associated with negative effect upon graft and recipient survival in most patient subgroups. The optimal time in between graft failure and re-transplant was not evaluated in this study. Further prospective studies might be needed to confirm the observed effects.