25 Management of end-stage liver disease and liver transplantation
Case
A 57-year-old female with primary biliary cirrhosis presents with new onset peripheral oedema and abdominal swelling. Her husband has noticed increasing jaundice and mild attention and concentration changes. Vital signs reveal a mild fever of 37.3° Celsius. The examination is notable for mild confusion, scleral icterus, asterixis, peripheral oedema and a distended abdomen with shifting dullness. Initial laboratory work reveals a total bilirubin of 9.5 mg/dL (normal range 0.1 –1.0), alanine amino-transferase of 68 U/L (7–45), aspartate amino-transferase of 87 U/L (8–43) and alkaline phosphatase of 322. The International Normalized Ratio (INR) is elevated at 1.3 (0.9–1.2) as is the creatinine at 1.5 mg/dL (0.6–1.1), both of which had been previously normal.
End-stage Liver Disease
Compensated cirrhosis
The most common severity assessment tools in use are the Child-Turcotte-Pugh (CTP) score and the Model for End Stage Liver Disease (MELD) score. The CTP score was originally devised to risk stratify cirrhotic patients in need of portocaval shunt surgery due to oesophageal variceal bleeding and incorporates bilirubin, albumin and prothrombin time as well as encephalopathy and ascites measurements (see Table 24.6).
The MELD score was first developed to predict short-term prognosis in patients undergoing TIPS. The MELD score (http://www.unos.org/resources/meldpeldcalculator.asp) is based on three continuous, objective variables: bilirubin, creatinine and the INR of prothrombin time. Patients are assigned a score based on these three variables, from 6 through 40, corresponding to a 3-month survival of nearly zero and over 80% respectively. The MELD score has been validated as an accurate predictor of survival in acute liver failure, alcoholic hepatitis, a variety of chronic liver diseases and variceal bleeding, amongst others.
A patient with cirrhosis who has not developed jaundice or portal hypertensive complications of hepatic encephalopathy, ascites or variceal bleeding is ‘well compensated’, meaning he or she has adequate hepatic reserve. These patients are often categorised as Child-Turcotte-Pugh class (CTP) A. The median survival age in this group is 9–12 years. Since there are no available medical treatments to reverse cirrhosis, most management strategies are directed towards prevention.
Medication counselling
Paracetamol (acetaminophen) can be hepatotoxic above a dose of 4 g/day. Certainly, patients with concurrent alcohol use or malnutrition can experience additional liver injury at lower doses of paracetamol. In this subset of patients, it is probably safest to avoid chronic dosing of paracetamol, but a low dose (2 g/day) one time or infrequent dosing appears safe. In other cirrhotic patients, paracetamol at doses under 4 g/day for short periods of time appear safe, but less than 2.6 g/day is now the standard of care. The chronic use of paracetamol has not been studied in cirrhotic patients, thus most hepatologists will recommend dose reduction (2 g/day in divided doses) for longer term dosing. Many over-the-counter herbal medications can be hepatotoxic and can cause acute liver failure and thus should be avoided.
Hepatocellular carcinoma
Several treatment options are available for HCC including resection, locoregional therapy such as transarterial chemoembolisation (TACE), radiofrequency ablation (RFA) and liver transplantation. Radiofrequency ablation technique utilises a probe inserted percutaneously into the tumour with ultrasound or CT guidance and induces coagulative necrosis from heat generated by electromagnetic radiation. TACE delivers small embolic particles and a chemotherapeutic agent (cisplatin or doxorubicin commonly) to deprive the tumour of its vascular supply and concomitantly deliver cytotoxic therapy, resulting in tumour hypoxaemia and necrosis.