The United States Experience with Combined Lung and Liver Transplantation

L. R. Kugler¹, A. Bilgili², C. Bobba¹, O. Sharaf³, Y. Stukov¹, J. Jacobs¹, T. Beduschi¹, M. Rackauskas^4
1University of Florida, Gainesville, Florida ²The University of Florida College of Medicine, Jacksonville, Florida ³University of Florida Health, Gainesville, Florida ⁴UF Shands Hospital, Gainesville, Florida

Purpose: Combined lung-liver transplant (CLLT) is a rare procedure utilized in individuals who have end-stage lung and liver disease. Recently this procedure has gained traction, with many academic centers performing CLLT for the first time. This study aims to describe the state of CLLT in the US and assess patient outcomes.

Methods: The United Network for Organ Sharing Database (UNOS) was queried for all adult patients (≥ 18 years) who received CLLT between October 1994 and March 2024. UNOS thoracic and liver data were merged utilizing an encrypted transplant identifier. Transplant sequence was determined by utilizing available individual organ ischemic times. Cumulative risk was assessed to determine primary causes of graft failure or death in lung-liver recipients. Risk stratification was defined based on patient survival status, lung graft status, or liver graft status at each of their respective time points as follows:
• Alive with no graft failure
• Primary lung graft failure
• Primary liver graft failure
• Death from non-graft causes
Post-transplant survival was further assessed utilizing Kaplan-Meier survival analysis. Three patients were excluded from competing risks and survival analysis due to missing survival data. Categorical and continuous variables are represented as % (n) and median [IQR], respectively.

Results: A total of 193 adult CLLTs were performed across 43 centers. Most of these transplants were bilateral lung and liver (92.7% [n=179]), with many being lung followed by liver (87.7% [n=157/179]). Of CLLT patients, 67.9% were male [n=131], and the median age at transplant was 47 years [25, 59]. The most common indication for transplant was cystic fibrosis (44.0%) [n=85]. Median ischemic time was 5 hours [3.9,6.2] and 8.16 hours [6.88,9.85] for lungs and liver respectively. Postoperatively, 3.7% [n=7] experienced stroke, 17.6% [n=33] required dialysis, and 7.7% [n=15] experienced an acute rejection episode. The average length of stay was 29 days [19,52].

Of CLLT patients, 10.9% [n = 21] suffered primary lung graft failure, and 5.2% [n = 10] suffered primary liver graft failure. Competing risks analysis estimated the cumulative incidence of primary lung graft failure at 5 years to be 11.6% (95% CI: 6.83-17.9%), primary liver graft failure at 5-years to be 5.48% (95% CI: 2.65-9.81%), and death from causes unrelated to graft failure at 5-years to be 23.4% (95% CI: 17.0-30.5%), Figure 1. Kaplan-Meier methods estimated 1-year survival was 81.5% (95% CI: 76.0-87.4%), 3-year survival was 70.4% (95% CI: 63.7-77.9%), and 5-year survival was 63.2% (95% CI 55.7-71.6%).

Conclusion: CLLT is a rare, but viable procedure option for those with end-stage lung disease, and end-stage liver disease. Descriptive analysis shows that most patients undergo this procedure due to cystic fibrosis. For most patients who die post-transplant, the cause is unrelated to primary liver or lung graft failure.

Identify the source of the funding for this research project: None