Normothermic ex vivo lung perfusion: Does the indication impact organ utilization and patient outcomes after transplantation?

Background: Ex vivo lung perfusion (EVLP) is being increasingly applied as a method to evaluate and treat donor lungs for transplantation. However, with the previous limited worldwide experience, no studies have been able to evaluate the impact of indication for EVLP on organ utilization rates and recipient outcomes after lung transplantation (LTx). We examined these outcomes in a large-cohort, single-center series of clinical EVLP cases.

Methods: All EVLP procedures performed at our institution between October 2008 and December 2017 were examined. The EVLPs were divided into 4 groups based on the indication for the procedure: group 1, high-risk brain death donors (HR-BDD); group 2, standard-risk donation after cardiac death (S-DCD); group 3, high-risk donation after cardiac death (HR-DCD); and group 4, logistics (LOGISTICS, the need for prolongation of preservation time or organ retrieval by a different transplantation team).

Results: During the study period, a total of 1106 lung transplants were performed in our institution. In this period, 372 EVLPs were performed, 255 (69%) of which were accepted for transplantation, resulting in 262 transplants. Utilization rates were 70% (140 of 198) for group 1, 82% (40 of 49) for group 2, 63% (69 of 109) for group 3, and 81% (13 of 16) for group 4 (P = .42, Fisher's exact test). Recipient age (P = .27) and medical diagnosis (P = .31) were not different across the 4 groups. Kaplan-Meier survival by EVLP indication group demonstrated no differences. Thirty-day mortality was 2.1% in group 1, 5% in group 2, 2.9% in group 3, and 0% in group 4 (P = .87, Fisher's exact test). The median days of mechanical ventilation, intensive care unit stay, and hospital stay were 2, 4, and 21 in group 1; 2, 3, and 21 in group 2; 3, 5, and 28 in group 3; and 2, 4, and 17 in group 4 (P = .29, .17, and .09, respectively, Kruskal-Wallis rank-sum test).

Conclusions: Clinical implementation of EVLP has allowed our program to expand the annual lung transplantation activity by 70% in this time period. It has improved confidence in the utilization of DCD lungs and BDD lungs, with an average 70% utilization of post-EVLP treated donor lungs with excellent outcomes, while addressing significant challenges in donor lung assessment and the logistics of "real-life" clinical lung transplantation.