The Contralateral Lung: An Opportunity for Lung Transplant at a Lower Lung Allocation Score?

Background: In more than half of single-lung transplants (SLTs), the second or contralateral lung is discarded. We evaluated the use of the contralateral lung and its role in enabling single-lung transplantation at a lower Lung Allocation Score (LAS). Methods: We identified adult SLT recipients from 2015 to 2022 using the United Network for Organ Sharing/Organ Procurement and Transplantation Network database. Post-SLT survival was compared with Kaplan-Meier curves and multivariable Cox regression. Results: Of 4692 SLT recipients, 1246 (26.6%) received a contralateral lung. Contralateral lung recipients had a lower median LAS (36.9 [33.5-42.2] vs 40.4 [35.3-49.8]; P < .001) and higher median sequence number (26 [11-65.8] vs 8 [3-25]; P < .001). Survival was higher in contralateral vs first SLT recipients (median survival, 5.0 [95% CI, 4.7-5.3] years vs 4.5 [95% CI, 4.2-4.7] years; log-rank P < .001). This difference persisted as a 14% decreased hazard of mortality for contralateral recipients after adjustment (adjusted hazard ratio, 0.86 [0.77-0.95]; P = .004). Of SLT donors, 1309 (37.4%) had both lungs accepted for use. Conclusions: In this nationwide analysis, we found that contralateral SLT recipients received SLTs at a lower median LAS without compromising outcomes, suggesting that contralateral single-lung transplantation may provide a valuable approach to help expand the donor pool.