Is there a safe cold ischemia time interval for the renal graft?

Abstract

ObjectiveIt is aimed to characterize the true relationship of the cold ischemia time (CIT) with graft survival and with the principal post-transplantation events. Material and methodsWe analyzed 378 kidney transplants, studying the relationship of the CIT with graft survival using a univariate analysis according to the COX model and seeking the optimum cutoff according to the Kaplan–Meier method and log-rank test. The relationship between CIT and the principal events of the post-transplant was studied using the binary logistic regression. ResultsThe mean follow-up of all the group was 77.8 months (±51 SD) and the mean CIT was 14.8h (±5.1 SD). The univariate analysis revealed that the CIT was not related with the graft survival as a continuous variable (OR=1.04; 95% CI: 0.9–1.08; p>0.05). On establishing the cutoff at 18h, we found differences in the actuarial survival. Survival at 5 years was 91% with CIT <18h versus 84% with CIT >18h. Each hour of cold ischemia increased risk of delay in the graft function by 10% (OR=1.1; 95% CI: 1.05–1.15; p<0.001) and also conditioned a greater incidence of acute rejection (41.5% vs. 55.3%; p=0.02) and less time to the first rejection episode (72.6 days±137 vs. 272.2 days±614.8; p=0.023) after 18h. The CIT did not seem to be related (p<0.05) with the rest of the post-transplantation events, such as surgical complications or hospital admissions. ConclusionsIn our experience, cold ischemia under 18h does not seem to negatively affect graft survival.