Evaluating the Impact of Ex-Vivo Lung Perfusion on Organ Transplantation: A Retrospective Cohort Study.

Abstract

Ex-vivo lung perfusion (EVLP) sustains and allows advanced assessment of potentially useable donor lungs prior to transplantation, potentially relieving resource constraints. We sought to characterize the effect of EVLP on organ utilization and patient outcomes. We performed a retrospective, before-after cohort study using linked institutional data sources of adults wait-listed for lung transplant and donor organs transplanted in Ontario, Canada between 2005-2019. We regressed the annual number of transplants against year, EVLP use, and organ characteristics. Time-to-transplant, waitlist mortality, primary graft dysfunction, tracheostomy insertion, in-hospital mortality, and chronic lung allograft dysfunction (CLAD) were evaluated using propensity score-weighted regression. EVLP availability (P=0.01 for interaction) and EVLP use (P<0.001 for interaction) were both associated with steeper increases in transplantation than expected by historical trends. EVLP was associated with more donation after circulatory death (DCD) and extended-criteria donors transplanted, while the numbers of standard-criteria donors remained relatively stable. Significantly faster time-to-transplant was observed after EVLP was available (hazard ratio [HR] 1.64 [1.41-1.92]; P<0.001). Fewer patients died on the waitlist after EVLP was available, but no difference in the hazard of waitlist mortality was observed (HR 1.19 [0.81-1.74]; P=0.176). We observed no difference in the likelihood of CLAD before versus after EVLP was available. We observed a significant increase in organ transplantation since EVLP was introduced into practice, predominantly from increased acceptance of DCD and extended-criteria lungs. Our findings suggest that EVLP-associated increases in organ availability meaningfully alleviated some barriers to transplant.