N Liver transplantation
Liver transplantation is the treatment of choice for patients with acute and chronic end-stage liver disease. The liver transplant operation can be divided into three stages: (1) hepatectomy; (2) anhepatic phase, which involves the implantation of the liver; and (3) postrevascularization, which involves hemostasis and reconstruction of the hepatic artery and common bile duct. Hepatectomy can be associated with marked blood loss. Contributing factors include severe coagulopathy, severe portal hypertension, previous surgery in the right upper quadrant, renal failure, uncontrolled sepsis, retransplantation, transfusion reaction, venous bypass–induced fibrinolysis, primary graft nonfunction, and intraoperative vascular complications.
The anhepatic phase may be associated with significant hemodynamic changes. This stage consists of implantation of the liver allograft with or without venovenous bypass. Benefits of using the venovenous bypass system include improved hemodynamics during the anhepatic phase, decreased blood loss, and possible improvement of perioperative renal function. Complications of using the system include pulmonary embolism, air embolism, brachial plexus injury, and wound seroma or infection.
Before revascularization, the liver must be flushed with a cold solution (i.e., albumin 5%) through the portal vein and out the infrahepatic vena cava. The reperfusion of the liver may be the most critical part of the operation. Patients may experience pulmonary hypertension followed by right ventricular failure and profound hypotension. The hepatic artery reconstruction is performed after stabilization of the patient after revascularization. The last part involves hemostasis, removal of the gallbladder, and reconstruction of the bile duct.
Patients requiring liver transplantation often have multiorgan system failure. Because of the emergency nature of the surgery, there may be insufficient time available for customary evaluation and correction of abnormalities.