Impact of Cold Ischemia Time on Graft Survival Among ECD Transplant Recipients: A Paired Kidney Analysis

Abstract

Delays in expanded criteria donor (ECD) kidney placement increases cold ischemia times (CIT) potentially leading to discard. The effect of increased CIT on ECD kidney transplant outcomes is unknown. We evaluated paired ECD kidneys (derived from the same donor transplanted to different recipients) from the SRTR registry transplanted between 1995 and 2009 (n = 17 514). To test the effect of CIT, we excluded paired transplants with the same CIT (n = 3286). Of 14 230 recipients (7115 donors) the median difference in CIT was 5 h (Q1 = 3 h, Q3 = 9 h). Delayed graft function (DGF) was significantly more likely between pairs with greater CIT (35% vs. 31%, p < 0.001) including substantially higher rates for CIT differences ≥15 h (42%). Overall graft loss was not significantly different between recipients with higher CIT relative to paired donor recipients with lower CIT (p = 0.47) or for pairs with differences of 1-3 h (p = 0.90), 4-9 h (p = 0.41), 10-14 h (p = 0.36) or ≥15 h (p = 0.10). Results were consistent in multivariable models adjusted for recipient factors. Although increasing cold ischemia time is a risk factor for DGF among ECD kidney transplants, there is no effect on graft survival which may suggest an important utility for donor kidneys that may not currently be considered viable.

Are Octogenarians With End-Stage Renal Disease Candidates for Renal Transplantation?

“…13,15 Compared with other transplant centers, the recipients in our study had a relatively short time on dialysis before transplantation, and the mean cold ischemia time was generally short. 16,17 …”

The Association of Center Performance Evaluations and Kidney Transplant Volume in the United States

“…Although it should be acknowledged that this effect was relatively minor, differences between centers based on performance may suggest a reluctance to accept nonlocal donor offers which are generally perceived to convey additional risk among low performing centers (23). However, there are also recent studies to suggest that donor kidneys with extended cold ischemia time are at risk for delayed graft function but not for longterm outcomes including graft loss and death that would affect performance evaluations (24,25). These results may suggest that donor kidneys that are otherwise viable and may not be associated with diminished outcomes applicable for performance evaluations are turned down by low performing centers more frequently but without significant potential gain on report cards.…”

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“…22 There are studies claiming that, after a cold ischemia time of 36 hours, outcomes after kidney transplant significantly worsen, whereas other studies claim that the cold ischemia time is of no great significance. 22,23 The mean cold ischemia time in our study was significantly lower than 36 hours, which could explain why it did not affect DGF.…”