ECMO and lung transplantation

Extracorporeal membrane oxygenation (ECMO) is an invaluable tool in lung transplantation. Originally developed to support patients in critical heart or respiratory failure, its use as a bridge to organ transplant (BTT) for critically ill patients with end-stage lung disease has increased in recent decades. In 2018, nearly 6% of all lung transplants in the United States were performed with an ECMO bridge. Most centers use ECMO preoperatively as a strategy to rehabilitate awake patients so they can ambulate before lung transplantation. Intraoperatively, it has been used for patients with pulmonary hypertension or those unable to tolerate single lung ventilation. Some centers advocate ECMO for all lung transplant surgeries. It provides excellent circulatory and respiratory support, well controlled reperfusion, low levels or no anticoagulation, and decreased inflammatory response compared to cardiopulmonary bypass. The downside of ECMO is the possibility of air embolism, a rare but devastating complication. Post-transplant, it is the standard care for patients with severe primary graft dysfunction (PGD). Since high ventilatory settings and elevated oxygen concentration are deleterious to lung transplants recipients, venovenous (VV) ECMO is applied liberally in this setting. ECMO also allows time for the characteristic pulmonary edema of PGD to subside on its own or be treated. For all these reasons, ECMO has found a niche in lung transplantation and is part of the clinical armamentarium every lung transplant surgeon needs to know and manage.