Portal Hypertension
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Direct answer
Portal hypertension is raised pressure in the portal venous system, classified by the site of obstruction: prehepatic (portal vein thrombosis), intrahepatic presinusoidal (schistosomiasis — the commonest cause worldwide — and non-cirrhotic portal fibrosis, an important Indian entity), sinusoidal (cirrhosis, the commonest cause overall), and posthepatic or postsinusoidal (hepatic vein thrombosis of Budd-Chiari syndrome and veno-occlusive disease). The consequences follow from decompression through portosystemic collaterals — bleeding oesophageal varices above all — plus congestive splenomegaly with hypersplenism, ascites and portosystemic encephalopathy.
What you must remember
- Classification by site: prehepatic (portal vein thrombosis, often from neonatal sepsis or hypercoagulability), presinusoidal (schistosomiasis eggs, non-cirrhotic portal fibrosis, sarcoidosis, early primary biliary cholangitis), sinusoidal (cirrhosis of any cause), postsinusoidal (veno-occlusive disease/sinusoidal obstruction syndrome) and posthepatic (Budd-Chiari, right heart failure, constrictive pericarditis).
- Cirrhosis as commonest overall: architectural distortion and fibrosis raise intrahepatic resistance while splanchnic hyperaemia raises inflow; clinically significant when the hepatic venous pressure gradient exceeds about 10 mm Hg.
- Non-cirrhotic portal fibrosis: a presinusoidal cause common in India — young patients with well-preserved synthetic function presenting with variceal bleeding and hypersplenism, with portal vein cavernoma on imaging.
- Collateral decompression: gastro-oesophageal varices (the lethal route), anorectal varices, recanalised paraumbilical veins forming caput medusae and retroperitoneal collaterals.
- Consequences: variceal haemorrhage with massive haematemesis, congestive splenomegaly causing pancytopenia from hypersplenism, ascites from sinusoidal hypertension plus hypoalbuminaemia and hyperaldosteronism, and portosystemic encephalopathy from shunted ammonia.
- Budd-Chiari syndrome: hepatic vein thrombosis in hypercoagulable states, myeloproliferative neoplasms, pregnancy and membranous webs — painful hepatomegaly, ascites and a nutmeg-like congested liver that can infarct centrilobular zones.
- Management directions: beta blockade and endoscopic band ligation for variceal prophylaxis, transjugular intrahepatic portosystemic shunt for refractory bleeding or ascites, and treatment of the underlying cause per current guidance.
Common confusion
The classification sites are repeatedly swapped: schistosomiasis is presinusoidal (egg granulomas in portal tracts) with preserved hepatocyte function until late, whereas cirrhosis is sinusoidal with poor function; this distinction drives prognosis and transplant decisions. Oesophageal varices versus Mallory-Weiss tears both bleed after vomiting-contexts, but varices give painless massive haematemesis. Ascites mechanisms blend portal pressure, hypoalbuminaemia and secondary hyperaldosteronism — do not attribute it to pressure alone.
Exam-focused takeaway
Stems describe a young Indian man with variceal bleed, splenomegaly and normal liver tests (non-cirrhotic portal fibrosis), a farmer with hepatosplenomegaly from fresh-water exposure (schistosomiasis), or a woman with a thrombophilia and painful ascites (Budd-Chiari). Questions ask to classify the site of obstruction, name the collateral pathways, or match the consequence — varices, hypersplenism, ascites, encephalopathy — to its mechanism.
Frequently asked questions
What is the commonest cause of portal hypertension worldwide and locally?
Cirrhosis is the commonest overall, while schistosomiasis is the commonest presinusoidal cause globally and non-cirrhotic portal fibrosis is an important cause in India.
How is portal hypertension classified anatomically?
Prehepatic, intrahepatic presinusoidal, sinusoidal, postsinusoidal and posthepatic, according to the site of resistance to portal flow.
What is caput medusae?
Periumbilical collaterals from a recanalised paraumbilical vein fanning outward from the umbilicus in chronic portal hypertension.
Why does hypersplenism develop?
Congestive splenomegaly sequesters and destroys blood cells, producing anaemia, leucopenia and thrombocytopenia in parallel with the splenomegaly.
What is Budd-Chiari syndrome?
Thrombosis of hepatic veins causing painful hepatomegaly, ascites and centrilobular congestion, typically in hypercoagulable or myeloproliferative states.