Bridging the Gap: A Comparative Analysis of Patients Requiring Mechanical Ventilation or ECMO as a Bridge to Lung...

We compared trends and outcomes of lung transplant recipients who were bridged to transplantation using mechanical ventilation (MV) or extracorporeal membrane oxygenation (ECMO) during the new Composite Allocation Score (CAS) era or the previous Lung Allocation Score (LAS) era.

The United Network for Organ Sharing database was queried for all adult lung transplant recipients bridged to transplant with MV or ECMO during the LAS (April 5, 2005 to August 3, 2023) or CAS (September 3, 2023 to September 30, 2024) era. Baseline patient characteristics, perioperative outcomes, and short-term survival were compared between eras.

A total of 2982 patients were included: 1866 with ECMO-bridge (LAS-ECMO: 1597; CAS-ECMO: 269) and 1116 with MV-bridge (LAS-MV: 1072; CAS-MV: 44). MV-bridge use was higher during LAS than CAS (LAS, 2.9% vs. CAS, 0.8%, p < 0.001), whereas ECMO-bridge was higher in the CAS era (LAS, 4.3% vs. CAS, 5.3%, p = 0.03). Recipient age was higher for both MV-bridge and ECMO-bridge cohorts in the CAS era. Median waitlist times were shorter, and median ischemic time and donor organ travel distances were longer in the CAS era for both MV and ECMO cohorts. Perioperative outcomes and 30-day and 90-day survival were comparable between eras. Waitlist mortality and delisting rates for medical deterioration were lower in the CAS era.

Rates of ECMO-bridge to transplant increased in the CAS era compared to the LAS era. Although the donor lung travel distances were longer, perioperative outcomes were comparable to those of the LAS era. Long-term outcomes of BTT candidates in the CAS era remain to be seen.