Lung Transplantation with Ex Vivo Lung Perfusion: A United Network for Organ Sharing Database Analysis

M. P. Weber¹, S. D. Young¹, K. J. Ryan², P. Rothenberg², J. Mehaffey², A. Hayanga², P. Carrott^1
1University of Virginia, Charlottesville, Virginia ²West Virginia University, Morgantown, West Virginia

Purpose: Ex-vivo lung perfusion (EVLP) is an evolving approach to increase donor lung availability for transplantation. However, there is a paucity of large studies reviewing the impact of EVLP and the different structures of perfusion teams on short and long-term outcomes. We sought to better characterize the effects of these processes.

Methods: All adult lung transplant patients listed from 2018 to 2023 were evaluated utilizing the United Network for Organ Sharing (UNOS) database. Re-transplant and multiorgan transplant recipients were excluded. Patients were stratified based on EVLP use for donor lungs. Information was obtained regarding the duration of EVLP, the structure of the perfusing team: Organ Procurement Organization (OPO), Transplant Program (TP), External Perfusion Center (EPC), and the perfusion location. Univariate and Kaplan-Meier analyses were employed to assess for differences. Risk adjustment was performed with Cox proportional-hazards and logistic regression models in assessing overall survival, graft survival, and the need for extracorporeal membrane oxygenation (ECMO) support at 72 hours post-lung transplant.

Results: A total of 12,081 patients were identified with EVLP use in 703 patients including 31 donor lungs perfused by the OPO, 446 by the TP, and 226 by an EPC. Recipients in the EVLP group had a lower lung allocation score (48.6 vs 50.6, p< 0.01). Additionally, EVLP donors were older (38.5 years vs 35.8 years, p< 0.001), had a higher BMI (28.3 vs 26.7, p < 0.001), and had lower PO2 at the time of allocation (377.1 vs 405.7, p < 0.001). For those organs on EVLP, the median perfusion time was 250 minutes, and EVLP lungs had a longer ischemic time (11.7 hours vs 5.7 hours, p < 0.001). Prior to accounting for baseline differences between groups, EVLP recipients had worse overall survival (log-rank overall, p=0.03). However, after risk adjustment to account for baseline recipient differences, use of EVLP was not associated with overall survival (p=0.44, Figure 1). All EVLP perfusion teams (OPO: 0.94 [0.51-1.70], p=0.83; TP 1.07 [0.87-1.32], p=0.53; EPC: 1.16 [0.85 -1.60], p=0.34) were also not associated with overall survival. Notably, perfusion by an EPC was found to be protective against the need for ECMO at 72 hours (0.56 [0.34-0.91], p=0.02).

Conclusion: Modern utilization of EVLP regardless of perfusion team does not negatively impact survival, and perfusion by an EPC is protective against ECMO at 72 hours post-transplant. These data support the use of EVLP to increase the donor pool for effective transplantation of carefully selected marginal organs.

Identify the source of the funding for this research project: WVU-UVA CRISP Research Grant