Editorial: Ex vivo graft preservation and modification

Liver transplantation is a highly successful treatment, but is severely limited by the shortage in donor organs. However, many potential donor organs cannot be used; this is because sub-optimal livers do not tolerate conventional cold storage and there is no reliable way to assess organ viability preoperatively. Normothermic machine perfusion maintains the liver in a physiological state, avoids cooling and allows recovery and functional testing. Here we show that, in a randomized trial with 220 liver transplantations, compared to conventional static cold storage, normothermic preservation is associated with a 50% lower level of graft injury, measured by hepatocellular enzyme release, despite a 50% lower rate of organ discard and a 54% longer mean preservation time. There was no significant difference in bile duct complications, graft survival or survival of the patient. If translated to clinical practice, these results would have a major impact on liver transplant outcomes and waiting list mortality.

What are the long-term outcomes of transplant recipients of donor lungs treated with ex vivo lung perfusion? In this cohort study, donor lungs treated with ex vivo lung perfusion were more injured than conventional donor lungs, but there was no difference in survival or chronic lung allograft dysfunction between recipients of conventional donor lungs and donor lungs treated with ex vivo lung perfusion. During the era of ex vivo lung perfusion, transplant activity has increased without compromising outcomes in lung transplant recipients. The mortality rate for individuals on the wait list for lung transplant is 15% to 25%, and still only 20% of lungs from multiorgan donors are used for lung transplant. The lung donor pool may be increased by assessing and reconditioning high-risk extended criteria donor lungs with ex vivo lung perfusion (EVLP), with similar short-term outcomes. To assess the long-term outcomes of transplant recipients of donor lungs treated with EVLP. This retrospective cohort single-center study was conducted from August 1, 2008, to February 28, 2017, among 706 recipients of donor lungs not undergoing EVLP and 230 recipients of donor lungs undergoing EVLP. Donor lungs undergoing EVLP. The incidence of chronic lung allograft dysfunction and allograft survival during the 10-year EVLP era were the primary outcome measures. Secondary outcomes included donor characteristics, maximum predicted percentage of forced expiratory volume in 1 second, acute cellular rejection, and de novo donor-specific antibody development. This study included 706 patients (311 women and 395 men; median age, 50 years [interquartile range, 34-61 years]) in the non-EVLP group and 230 patients (85 women and 145 men; median age, 46 years [interquartile range, 32-55 years]) in the EVLP group. The EVLP group donors had a significantly lower mean (SD) Pa o 2 :fraction of inspired oxygen ratio than the non-EVLP group donors (348 [108] vs 422 [88] mm Hg; P  < .001), higher prevalence of abnormal chest radiography results (135 of 230 [58.7%] vs 349 of 706 [49.4%]; P  = .02), and higher proportion of smoking history (125 of 204 [61.3%] vs 322 of 650 [49.5%]; P  = .007). More recipients in the EVLP group received single-lung transplants (62 of 230 [27.0%] vs 100 of 706 [14.2%]; P  < .001). There was no significant difference in time to chronic lung allograft dysfunction between the EVLP and non-EVLP group (70% vs 72% at 3 years; 56% vs 56% at 5 years; and 53% vs 36% at 9 years; log-rank P  = .68) or allograft survival between the EVLP and non-EVLP groups (73% vs 72% at 3 years; 62% vs 58% at 5 years; and 50% vs 44% at 9 years; log-rank P  = .97) between the 2 groups. All secondary outcomes were similar between the 2 groups. Since 2008, 230 of 936 lung transplants (24.6%) in the Toronto Lung Transplant Program were performed after EVLP assessment and treatment. Use of EVLP-treated lungs led to an increase in the number of patients undergoing transplantation, with comparable long-term outcomes. This cohort study assesses the long-term outcomes of transplant recipients of donor lungs treated with ex vivo lung perfusion.

Given high dialysis mortality rates for patients older than 60 years, accepting a kidney with a high Kidney Donor Profile Index (KDPI) score could enable earlier and potentially preemptive transplantation (preKT). However, evidence regarding the risks of high KDPI allografts in older patients is limited. Our objective was to determine the relative benefit for older patients of KDPI greater than 85% transplant either preemptively or not compared with remaining on the waitlist.