Chronic liver disease, cirrhosis and portal hypertension: Viva

Branch 1: Assessing portal hypertension

The candidate should recognise that a child with biliary atresia and a Kasai portoenterostomy is at high risk for progressive fibrosis and portal hypertension, and that the thrombocytopenia of 78,000 per cubic millimetre is a strong clue to clinically significant portal hypertension from hypersplenism. The key is to interpret the platelet count not as an isolated abnormality but as a marker of splenic sequestration from portal venous congestion. [1]

A strong candidate would explain that the hepatic venous pressure gradient of 10 mmHg or more defines clinically significant portal hypertension, which is the threshold at which varices form and the risk of bleeding becomes real. The candidate should describe the focused examination looking for splenomegaly, ascites with shifting dullness, spider naevi, palmar erythema, and signs of chronic liver disease, and should request an abdominal ultrasound with Doppler to assess portal vein patency, flow direction, splenomegaly, and the presence of collaterals. [1]

If the examiner presses on the next step, the candidate should name upper gastrointestinal endoscopy as the gold standard for diagnosing and characterising varices, and should explain that the finding of large varices or red wale signs would prompt consideration of primary prophylaxis with either non-selective beta-blockers or endoscopic variceal ligation. [1]

Branch 2: Primary prophylaxis of variceal bleeding

If asked about the choice of primary prophylaxis, the candidate should present both options honestly. Non-selective beta-blockers such as propranolol at 1 to 2 mg per kg per day, titrated to reduce the resting heart rate by approximately 25 per cent, reduce portal pressure through beta-1 mediated reduction in cardiac output and beta-2 mediated splanchnic vasoconstriction. Endoscopic variceal ligation mechanically eradicates varices through serial banding sessions every 2 to 4 weeks under general anaesthesia. [2]

A strong candidate should acknowledge that the Cochrane reviews by Cifuentes and Gana found insufficient evidence from randomised trials to determine which strategy is superior in children, and that the choice is currently guided by extrapolation from adult data, individual patient factors (such as the ability to tolerate beta-blockers, anaesthetic risk, and adherence), and centre preference. This honest answer, rather than pretending the evidence is settled, demonstrates evidence-based reasoning. [2]

If the examiner asks about adverse effects, the candidate should mention fatigue, bradycardia, and hypotension with beta-blockers, and oesophageal ulceration, stricture, and anaesthetic risk with band ligation. The candidate should note that beta-blockers can mask the symptoms of hypoglycaemia, which is relevant in a child with liver disease. [2]

Branch 3: Hepatopulmonary syndrome

If the examiner asks about respiratory complications, the candidate should define hepatopulmonary syndrome as the triad of chronic liver disease or portal hypertension, arterial hypoxaemia with a PaO2 under 80 mmHg or an alveolar-arterial gradient over 15 mmHg, and intrapulmonary vascular dilatation demonstrated by contrast echocardiography or a technetium-99m macroaggregated albumin brain uptake scan. [3]

A strong candidate should explain the pathophysiology: nitric oxide-mediated pulmonary vasodilation causes ventilation-perfusion mismatch and right-to-left shunting, which is worse in the basal lung segments and therefore produces platypnoea (dyspnoea on standing) and orthodeoxia (a fall in oxygen saturation on standing). Digital clubbing and cyanosis are characteristic physical findings. [3]

If asked about management, the candidate should explain that hepatopulmonary syndrome is an independent indication for liver transplantation, that a PaO2 under 60 mmHg confers additional transplant priority in many allocation systems because it predicts worse survival without transplant, and that hepatopulmonary syndrome may resolve completely after successful transplantation. The candidate should contrast this with portopulmonary hypertension, which may worsen after transplantation and is a relative contraindication unless pulmonary pressures are controlled. [3]