Sarah Bos

71 Hemostatic complications in hepatobiliary surgery 5 Hemorrhagic Complications Bleeding may complicate hepatobiliary surgery. Clinically relevant bleeding rates vary widely between centers, but blood loss requiring blood product transfusion is not uncommon. In a published series from our center, one-third of patients undergoing partial hepatectomy required red blood cell transfusions,(32) and mean red blood cell requirements during liver transplantation were eight units. (57) Although the improvements in surgical and anesthesiologic techniques have contributed to a substantial decrease in blood loss and transfusion requirements over time,(4) profound blood loss may occur in individual patients. The main causes of blood loss in hepatobiliary surgery consist of surgical and patient- related factors, which includes altered hemostasis in those patients with the end-stage liver disease.(5) Factors that may contribute to bleeding during partial hepatectomy include the quality of liver tissue to be transected, the method of parenchymal transection, and the central venous pressure.(2,3,58,59) In liver transplantation, factors that may con- tribute to perioperative blood loss are severity and etiology of liver disease, severity of portal hypertension, nutritional state, concomitant renal failure, length of the cold ischemia time, previous surgical procedures, and the type of surgical technique used (vena cava replacement vs. piggyback technique).(4,60,61) Although blood loss is manageable in the vast majority of patients by surgical repair and transfusion of blood products, there are multiple reasons to limit blood loss as much as possible. Blood loss and blood product requirements have been dose-dependently linked to adverse outcomes including mortality in patients undergoing partial hepatectomy or liver transplant surgery.(4,62) Although mechanisms that may be involved in deleterious effects of blood product transfusion in patients undergoing hepatobiliary surgery are in- completely understood, they include general transfusion reactions including transfusion- related acute lung injury, which appears more prevalent in patients undergoing hepatobiliary surgery as compared with patients transfused in other contexts.(63) Also, transfusion-associated circulatory overload may contribute to exacerbation of bleeding as it increases portal hypertension.