Impact of Ex Vivo Lung Perfusion on Utilization of Potential Lung Donors in the United States

Abstract

Ex vivo lung perfusion (EVLP) is a contemporary tool which aims to improve the utilization of marginal donor lungs. Little is known about the impact of EVLP on the utilization of potential donor organs on a national scale in the United States. This study examines whether EVLP is associated with increased lung utilization among potential donors in a contemporary cohort of United States patients. We used the Organ Procurement and Transplantation Network database to identify all adult potential deceased organ donors, including donors after brain death (DBD) and donors after circulatory determination of death (DCD) in the modern era of EVLP (2015-2018). Our main covariate of interest was use of EVLP, defined by perfusion of either or both lungs prior to transplantation. The primary study endpoint was lung utilization, defined as successful single or double lung transplantation of a potential organ donor. Our analysis was performed using a multivariable logistic regression model adjusted for donor demographics, clinical characteristics, and risk factors. We evaluated the association between EVLP and lung utilization separately among the DCD and DBD potential donor populations. We identified 11,857 potential donors of whom 1,608 (14%) were DCDs. EVLP use increased from 2% to 4% annually during the study period. Among DBD potential donors, EVLP was used in 2% (n=22). Lung utilization was 62% (n=6188) in grafts recovered without EVLP and 49% (n=108) with EVLP. Recovery with EVLP was associated with significantly lower lung utilization (adjusted OR 0.6, 95% CI 0.4-0.8) among DBD potential donors. Among DCD potential donors, EVLP was used in 6% (n=100). Lung utilization was 15% (n=234) without EVLP and 49% (n=49) with EVLP. Recovery with EVLP was associated with significantly improved lung utilization among DCD potential donors (adjusted OR 2.8, 95% CI 1.7-4.6). EVLP is associated with significantly higher lung utilization among potential DCD donors in the United States. In DBD donors, use of EVLP was likely a surrogate for unmeasured high-risk features and appeared to represent attempted salvage of organs that would otherwise have been discarded. EVLP can be a valuable tool to improve lung utilization among DCD donors and if employed more widely, may increase the pool of organs available for transplantation.