Control of the inflow and outflow system during liver resection.

Control of blood loss is a serious problem during liver resection. Bleeding from the inflow system can be controlled by the Pringle maneuver. The time limit for clamping is up to 10-15 min. A shortcoming of the Pringle maneuver is that it causes blood congestion in the portal vein. To avoid this problem other techniques have been developed including selective vascular occlusion and selective clamping of segmental branches. Bleeding from the outflow system is closely related to central venous pressure (CVP). Lowering the CVP reduces blood loss; in particular, keeping CVP <5 cmH(2)O by anesthesiological management is a simple and effective way to reduce blood loss. CVP remains high in some cases despite anesthesiological efforts, but in these circumstances other techniques are available including inferior vena cava clamping below the liver and intraoperative blood salvage.