What is the most significant advantage of VV ECMO over VA ECMO?

The primary advantage of VV ECMO (venovenous extracorporeal membrane oxygenation) over VA ECMO (venoarterial extracorporeal membrane oxygenation) lies in its ability to preserve unaffected pulmonary hemodynamics. VV ECMO is specifically designed for patients with respiratory failure where the heart remains functioning adequately. By diverting blood from the venous system, it oxygenates the blood directly without increasing the overall cardiac output or burdening the heart.

In contrast to VA ECMO, which supports both cardiac and pulmonary function by bypassing the heart and providing systemic circulation, VV ECMO maintains normal hemodynamics in the pulmonary circuit. This preservation is vital for patients who do not have perfusion-related issues but require significant respiratory support.

Unlike VA ECMO, which could potentially compromise pulmonary vascular resistance and function due to increased arterial pressures and flow, VV ECMO enables the native lungs to perform their function as effectively as possible, which is critical in managing patients with isolated lung failure. This demonstrates that VV ECMO specifically addresses the respiratory failure while minimizing impact on cardiovascular function.