Long-term outcomes of the international EXPAND trial of Organ Care System (OCS) Lung preservation for lung transplantation

Background: Portable ex vivo lung perfusion and ventilation with the Organ Care System (OCS) Lung system is a safe, effective method for preserving extended criteria donor (ECD) organs before transplant. Although this technology is increasingly used in the United States, no published data describe its effects on long-term graft function and patient outcomes. This study assessed long-term clinical outcomes after transplantation of ECD lungs that were preserved, recruited, and assessed with the OCS Lung. Methods: The EXPAND Lung Trial was a prospective, single-arm, multicenter, international trial conducted between January 2014 and July 2016; 5-year follow-up data were collected until December 2021. Double-lung donors were included who met any of four ECD criteria: age ≥55 years, PaO₂/FiO₂ ≤300 mmHg, expected ischemic time >6 h, and donation after circulatory death (DCD). Transplant recipients’ overall survival and 5-year incidence of bronchiolitis obliterans syndrome (BOS) were compared between the EXPAND cohort (n = 79) and a control cohort from the same centers within the same time period, who received donor lungs preserved with ice but not OCS (n = 644). This study is registered with ClinicalTrials.gov (NCT04194398). Findings: Overall survival was similar between the EXPAND and control cohorts; 5-year overall survival was 68.1% versus 66.5%, respectively (P = 0.795). The risk factors associated with overall survival were the degree of urgency for lung transplant and recipient age; 5-year survival was much greater for patients designated as non-urgent than for patients designated as urgent (73% versus 41%, P = 0.021). 5-Year BOS3-free survival was 60.4% for the EXPAND cohort and 63.7% for the control cohort (P = 0.599). Overall survival, development of BOS3, and development of any grade of BOS did not differ between the EXPAND and control cohorts. Interpretation: Among patients who underwent lung transplantation with ECD lungs, the use of OCS Lung resulted in excellent long-term clinical outcomes. This study's findings support the use of OCS Lung to expand the donor pool and provide a foundation for future studies comparing lung-preservation strategies. Funding: This study was funded by TransMedics.