Pre-assessment for hepato-pancreato-biliary and liver transplant surgery

Abstract

Liver transplantation is a complicated surgical procedure for the treatment of end-stage liver disease (ESLD). The operation frequently involves large volume resuscitation, massive transfusion of blood products and episodes of hemodynamic instability. Preoperative assessment and optimization is crucial for good outcomes. Assessment of the severity of ESLD and organ allocation is based on the model for end-stage liver disease (MELD) score and its recent modifications. Hepatic encephalopathy is scored using the West Haven Criteria and is commonly treated with lactulose and rifaximin. Cerebral edema is a complication of acute liver failure, and monitoring involves direct subdural transducer measurements as well as non-invasive methods such as optic nerve sheath diameter measurements with ultrasound. Cardiovascular diseases that warrant evaluation include cirrhotic cardiomyopathy, coronary artery disease, heart failure, valvular pathologies, infiltrative cardiomyopathies, and atrial fibrillation. Common preoperative investigations involve echocardiography, non-invasive stress tests, coronary angiography and cardiopulmonary function testing. Hepatopulmonary syndrome may be associated with severe hypoxemia but frequently resolves after transplantation. Portopulmonary hypertension requires a right heart catheterization for diagnosis and carries poor postoperative prognosis in severe, untreated cases. Current guidelines provide preoperative treatment and decision algorithms. Gastrointestinal complications of portal hypertension such as variceal hemorrhage, ascites and spontaneous bacterial peritonitis can cause acute exacerbations of chronic liver failure. Splanchnic vasodilation causes renal artery vasoconstriction and may result in hepatorenal syndrome and/or acute kidney injury. The coagulation system in ESLD is rebalanced. Isolated abnormal laboratory values such as an increased INR or thrombocytopenia do not always correspond to clinical coagulopathy, and point-of-care tests such as thromboelastography better predict the overall coagulation status. Preoperative evaluation of patients for non-transplant hepatico-pancreatic-biliary surgery includes the assessment of cardiovascular status using the guidelines provided the European Society of Cardiology, the European Society of Anesthesiology, the American College of Cardiology and the American Heart Association. Patients with liver disease or those undergoing significant liver resection should have a careful assessment of liver function.