Portal Hypertension

Elevated pressure within the portal venous system, most commonly from increased intrahepatic resistance in cirrhosis, though also caused by presinusoidal (portal vein thrombosis, schistosomiasis), sinusoidal (cirrhosis), and postsinusoidal (Budd-Chiari syndrome, right heart failure, constrictive pericarditis) processes.

Defined hemodynamically by a hepatic venous pressure gradient above 5 mmHg, with clinically significant portal hypertension generally considered to begin above 10 mmHg, the threshold above which varices and decompensation risk rise substantially.

Clinical consequences reflect the formation of portosystemic collaterals and splanchnic congestion: esophageal and gastric varices (asymptomatic until they bleed), splenomegaly with resulting hypersplenism (thrombocytopenia, mild leukopenia), caput medusae (dilated periumbilical veins), ascites, and hemorrhoids.

Portosystemic shunting also predisposes to hepatic encephalopathy, since toxins bypass hepatic clearance through collateral vessels as well as through impaired hepatocyte function.

Ultrasound with Doppler assesses portal vein patency and flow direction, splenic size, and can suggest portal hypertension from an enlarged portal vein diameter and collateral vessels.

Upper GI endoscopy screens for esophageal and gastric varices at the time cirrhosis is diagnosed, with surveillance intervals guided by variceal size and liver disease severity.

Transient elastography and platelet count are used together in some algorithms (the Baveno criteria) to identify patients who can safely avoid screening endoscopy given a low probability of high risk varices.

Hepatic venous pressure gradient measurement, an invasive catheter based technique, provides the definitive hemodynamic assessment and is used in specialist settings, particularly for research or complex cases.

CT or MR imaging assesses vascular anatomy in suspected Budd-Chiari syndrome or portal vein thrombosis.

Differentials for the underlying cause include cirrhosis of any etiology, portal vein thrombosis (malignant or bland, often in a hypercoagulable state or with underlying cirrhosis or malignancy), schistosomiasis (periportal fibrosis, presinusoidal, preserved synthetic function relative to the degree of portal hypertension), and Budd-Chiari syndrome.

Management focuses on preventing and treating the complications of portal hypertension rather than reducing portal pressure as an isolated goal, except through the following measures.

• Non-selective beta blockers (propranolol or carvedilol) reduce portal pressure and are used for primary prophylaxis of variceal bleeding in patients with medium to large varices, and for secondary prophylaxis after a bleed, combined with endoscopic variceal band ligation.

• Acute variceal hemorrhage management (resuscitation, vasoactive drugs, prophylactic antibiotics, urgent endoscopy) is detailed in the Cirrhosis entry.

• TIPS (transjugular intrahepatic portosystemic shunt) reduces portal pressure directly by creating a channel between the portal and hepatic venous systems, used for refractory variceal bleeding or refractory ascites, though it carries a significant risk of precipitating or worsening hepatic encephalopathy given the deliberate portosystemic shunting.

• Treat the underlying cause where possible (antiviral therapy for viral hepatitis, alcohol cessation, praziquantel for schistosomiasis, anticoagulation for portal vein thrombosis where appropriate).

• Liver transplantation is the definitive treatment where portal hypertension arises from decompensated cirrhosis meeting transplant criteria.

Referral: hepatology and gastroenterology for all confirmed portal hypertension, given the need for variceal surveillance, prophylaxis planning, and monitoring for decompensation.