Role of ECMO and percutaneous mechanical thrombectomy in the management of acute pulmonary embolism
Interventional treatment for hemodynamically unstable pulmonary embolism (PE) is now common due to the fact that unstable PE carries a significant 30-day mortality. Unstable PE is characterized by acute right ventricular failure, hypotension, and hypoxia, leading to cardiovascular collapse and cardiac arrest. Implementation of veno-arterial extracorporeal membrane oxygenation (VA-ECMO) acutely provides oxygenation support to improve hypoxia and offload the right ventricular (RV) pressure in the belief that rapid reduction of hypoxia and right ventricular (RV) pressure will provide a window for intervention. There are two strategies for using VA-ECMO during percutaneous pulmonary mechanical thrombectomy: VA-ECMO-assisted mechanical thrombectomy and mechanical thrombectomy with standby VA-ECMO. While the application of VA-ECMO in percutaneous mechanical thrombectomy is usually short-term, providers must be cognizant that it can be associated with substantial multisystem morbidity due to a systemic inflammatory response, hemorrhagic stroke, renal dysfunction, and bleeding, and these factors will impact outcomes. The evolving paradigm positions VA-ECMO combined with percutaneous pulmonary mechanical thrombectomy as the preferred combination for the high-risk PE patients (acute right ventricular failure, refractory shock, and cardiac arrest), while percutaneous pulmonary mechanical thrombectomy alone with standby VA-ECMO suffices for most intermediate PE patients.