Liver transplantation is an extremely complex surgical procedure that requires expertise and experience from both the surgeon and the anesthesiologist to ensure a successful outcome for the patient as it is the second largest organ and is intimately associated with major blood vessels such as the inferior vena cava, portal vein, and hepatic artery. There are currently over 6000 transplants performed annually in the United States and over 16,000 people actively listed for a liver transplant.
Patients with end-stage liver disease demonstrate the presence of a hyperdynamic circulation: high cardiac output with low systemic vascular resistance. The left ventricular ejection fraction should be greater than 60% (probably closer to 75%–80%), with the exception of fulminant hepatic failure (FHF). Cardiovascular changes have not had sufficient time to develop in patients with FHF, so the ejection fraction should be evaluated as the normal population.
All patients should be evaluated with a 12-lead electrocardiogram and an echocardiogram. The Revised Cardiac Risk Index (RCRI) has been validated in several studies to predict risk for perioperative cardiac events in patients undergoing noncardiac surgery. Dobutamine echocardiography is the stress test of choice for coronary artery disease and should be performed in patients with long standing diabetes mellitus and/or two or more of the following RCRI risk factors:
Age greater than 50
High-risk surgery (major vascular)
Ischemia heart disease (prior MI, angina, Q waves, ST-T changes)
History of congestive heart failure
History of stroke
Renal dysfunction (creatinine > 2, creatinine clearance < 60)
Causes of end-stage liver disease that may have direct myocardial involvement include alcoholic cirrhosis, Wilson’s disease, hemochromatosis, amyloidosis, and autoimmune hepatitis.
Hepatopulmonary syndrome is manifested by orthodeoxia (hypoxia worsened when standing) and platypnea (dyspnea worsened when standing). This condition is present in approximately 25% of patients with end-stage liver disease; however, few patients actually develop hypoxemia requiring supplemental oxygen. If suspected, obtain arterial blood gases on both room air and 100% oxygen. Transthoracic echocardiography will reveal intrapulmonary shunting upon the rapid injection of agitated saline (bubbles appear in the left atrium after 3–4 heart beats via the pulmonary veins, not a PFO).
Portopulmonary hypertension (PPHTN) is present in 2%–10% of patients presenting for liver transplantation. Mild PPHTN exists if the mean pulmonary arter pressure is greater than 25 mmHg, moderate if greater than 35–40 mmHg, and severe if greater 50 mmHg (assuming that the pulmonary capillary wedge pressure is less than 15 mmHg). If PPHTN exists, right heart function must be carefully evaluated by echocardiography and/or right heart catheterization. Right ventricular dysfunction in the face of PPHTN is a relative contraindication to orthotropic liver transplantation. Epoprostenol (prostacyclin or PGI2) may be used to manage PPHTN preoperatively and intra-operatively to manage acute pulmonary vasoconstriction. Although mild to ...