Vacuum Assistnet Venous Drainage – A Tutorial

Various approaches to venous return during cardiopulmonary bypass (CPB) have been described in the literature. However, venous drainage using a gravity siphon has been the most common means employed to effect venous drainage into the cardiopulmonary bypass circuit. Recently, minimally invasive and re-operative cardiac surgery strategies have advocated the application of various venous cannulae of reduced diameter. Under standard venous siphon conditions these small lumen venous cannulae demonstrate a high resistance to flow and thus a limited flow capacity. In most cases they are incapable of providing full cardiopulmonary support blood flow rates. As a result, augmented venous return (AVR) techniques, using active fluid aspiration principles, have been applied to optimize venous return flow rates through cannulae of reduced diameter and provide effective cardiopulmonary support and cardiac decompression.