Liver transplantation




N Liver transplantation




1. Introduction

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.



2. Preoperative assessment

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.



a) History and physical examination
(1) Cardiovascular: These patients can present with a hyperdynamic state, with increased cardiac output and decreased systemic vascular resistance. Many of these patients present with dysrhythmias, hypertension, pulmonary hypertension, valvular disease, cardiomyopathy (alcoholic disease, hemochromatosis, Wilson disease), and coronary artery disease.

(2) Respiratory: Patients are often hypoxic because of ascites, pleural effusions, atelectasis, ventilation–perfusion mismatch, and pulmonary arteriovenous shunting. This normally results in tachypnea and respiratory alkalosis. Pulmonary infection usually is a contraindication to surgery. Adult respiratory distress syndrome usually is not.

(3) Hepatic: Hepatitis serology and the cause of hepatic failure should be determined. Albumin is usually low, with consequent low plasma oncotic pressure leading to edema and ascites. The magnitude of action and duration of drugs may be unpredictable, although these patients generally have an increased sensitivity to all drugs, and the drug actions are prolonged.

Only gold members can continue reading. Log In or Register to continue

Related posts:

Default ThumbnailCardiomyopathy Default ThumbnailGuillain-barré syndrome Default ThumbnailSpinal cord injury Default ThumbnailHypoparathyroidism Default ThumbnailAortobifemoral bypass grafting Preoperative assessment
Tags:
Dec 2, 2016 | Posted by in ANESTHESIA | Comments Off on Liver transplantation

Full access? Get Clinical Tree
Get Clinical Tree app for offline access