Sarah Bos

64 CHAPTER 5 Abstract Hepatobiliary surgery is a well-known risk factor for thrombotic complications but is also associated with substantial perioperative blood loss. Given the central role of the liver in hemostasis, hepatobiliary surgery is frequently accompanied by complex changes in the hemostatic system. Increasing knowledge of these changes has resulted in an improved understanding of the etiology of some of the hemostatic complications. In the early postoperative period a prolongation of conventional coagulation test times, such as the prothrombin time, is frequently seen. Together with a decreased platelet count, this suggests a hypocoagulable state. The concomitant decline of anticoagulant factors and development of a von Willebrand factor/ ADAMTS13 (a disintegrin and metalloproteinase with a thrombospondin type 1 motif, member 13) imbalance, however, suggest a hypercoagulable state, potentially contributing to the risk of thromboembolism. Postoperative thromboprophylaxis should be initiated early to avoid thrombosis, and intensified prophylaxis might benefit high- risk patients. The risk of hemorrhagic complications during hepatobiliary surgery has diminished over time, mainly due to improved surgical and anesthesiological techniques. However, bleeding can still be profound in individual patients and is difficult to predict using (global) hemostasis tests. A restrictive transfusion and fluid infusion policy to maintain a low central venous pressure is crucial in prevention of perioperative bleeding. However, when active bleeding occurs, proactive prohemostatic management is required.