Prolonged ischemia is a known risk factor for delayed graft function (DGF) and its interaction with donor characteristics, the pathways of donor death, and graft outcomes may have important implications for allocation policies.
Using data from the Australian and New Zealand Dialysis and Transplant registry (1994-2013), we examined the relationship between total ischemic time with graft outcomes among recipients who received their first deceased donor kidney transplants. Total ischemic time (in hours) was defined as the time of the donor renal artery interruption or aortic clamp, until the time of release of the clamp on the renal artery in the recipient.
A total of 7542 recipients were followed up over a median follow-up time of 5.3 years (interquartile range of 8.2 years). Of these, 1823 (24.6%) experienced DGF and 2553 (33.9%) experienced allograft loss. Recipients with total ischemic time of 14 hours or longer experienced an increased odd of DGF compared with those with total ischemic time less than 14 hours. This effect was most marked among those with older donors (P value for interaction = 0.01). There was a significant interaction between total ischemic time, donor age, and graft loss (P value for interaction = 0.03). There was on average, a 9% increase in the overall risk of graft loss per hour increase in the total ischemic time (adjusted hazard ratio, 1.09; 95% confidence interval, 1.01-1.18; P = 0.02) in recipients with older donation after circulatory death grafts.
There is a clinically important interaction between donor age, the pathway of donor death, and total ischemic time on graft outcomes, such that the duration of ischemic time has the greatest impact on graft survival in recipients with older donation after circulatory death kidneys.
The duration of ischemic time has the greatest impact on kidney graft survival and there is on average, a 9% increase in the overall risk of graft loss per hour increase in the total ischemic time in recipients with older DCD kidneys. Supplemental digital content is available in the text.
1 Sydney School of Public Health, University of Sydney, Sydney, NSW, Australia.
2 Centre for Transplant and Renal Research, Westmead Hospital, Westmead, NSW, Australia.
3 University of Adelaide, Adelaide, Australia.
4 ANZDATA registry, Adelaide, SA, Australia.
5 Department of Renal Medicine, Sir Charles Gairdner Hospital, Perth, WA, Australia.
Received 19 January 2016. Revision received 13 May 2016.
Accepted 16 May 2016.
The authors declare no funding or conflicts of interest.
G.W. conceived, designed, analysed, and wrote the article. S.M., J.C.C., J.R.C., W.L., H.P., and A.T.P. advised on the presentation and writing of the article.
Correspondence: Germaine Wong, Sydney School of Public Health, University of Sydney, NSW 2145, Australia. (Germaine.firstname.lastname@example.org).
Supplemental digital content (SDC) is available for this article. Direct URL citations appear in the printed text, and links to the digital files are provided in the HTML text of this article on the journal's Web site (www.transplantjournal.com).