National Trends and Outcomes of Combined Lung-Liver Transplantation: An Analysis of the UNOS Registry

Combined lung-liver transplant (CLLT) is a complex yet life-saving procedure for patients with simultaneous end-stage lung and liver disease. Given the geographical allocation change to the lung allocation score (LAS) in 2017 and the recent SARS-CoV-2 outbreak in 2019, we aim to provide an updated analysis of the patient selection and outcomes of CLLTs.

The UNOS registry was used to identify all patients who underwent CLLT between January 2014 and June 2023. To account for the changes made to LAS in 2017, baseline characteristics and outcomes were compared between era 1 (before 2017) and era 2 (after 2017). Risk factors for mortality were analyzed using the Cox regression hazard models. Recipient survival of up to 3 years was analyzed using the Kaplan-Meier method.

117 CLLTs were performed (77.8% in era 2). Donor organs experienced significantly longer ischemic times (p = 0.039) and traveled longer distances (p = 0.025) in era 2. However, recipient (p = 0.79) and graft (p = 0.41) survival remained comparable at up to 3 years post-transplant between eras. CLLTs demonstrated similar long-term survival to isolated lung transplants (p = 0.73). Higher recipient LAS was associated with an increased mortality risk (HR 1.14, p = 0.034). Recipient diagnosis of idiopathic pulmonary fibrosis carried a 5.03-fold risk of mortality (p = 0.048) compared to those with cystic fibrosis.

In the post-2017 LAS change era, CLLTs are increasingly performed with comparable outcomes to isolated lung transplants. A careful, multidisciplinary approach to patient selection and management remains paramount to optimizing outcomes for this rare patient population.