venousvenous

Venovenous, or venovenous ECMO, is a form of extracorporeal life support in which venous blood is drained from the body, oxygenated outside the body, and returned to the venous system. It provides support for the lungs with the goal of allowing recovery from severe respiratory failure while the native lungs rest.

In typical venovenous ECMO, cannulas are placed in the venous system, commonly from the femoral vein and/or internal jugular vein. Blood is propelled by a pump through an artificial oxygenator, where gas exchange occurs, and returned to a central venous site, often near the right atrium. Because oxygenated blood re-enters the venous system rather than the arterial system, VV-ECMO mainly augments oxygenation and carbon dioxide removal rather than systemic circulation.

Indications include severe hypoxemic or hypercapnic respiratory failure unresponsive to optimized conventional ventilation, such as in ARDS or other critical airway or edema etiologies. VV-ECMO is contrasted with venoarterial ECMO (VA-ECMO), which also supports circulation by returning blood to the arterial system and is used for combined cardiac and pulmonary failure.

Risks and management considerations include bleeding from anticoagulation, thrombosis, infection, neurologic events, and hardware-related complications. Successful use requires specialized equipment, experienced teams, and careful patient selection.

Historically, ECMO techniques were developed in the 1970s–1980s, with venovenous approaches evolving as dedicated respiratory support options. The term venovenous ECMO is often shortened to VV-ECMO in clinical practice.