Measurement of portal pressure.

Portal pressure is estimated through measuring the hepatic venous pressure gradient (HVPG). The main clinical applications of HVPG measurements include diagnosis, classification, and monitoring of portal hypertension, risk stratification, identification of candidates for liver resection, and monitoring efficacy of β-adrenergic blockers. Clinically significant portal hypertension is defined as an HVPG of 10 mm Hg or greater. Patients who experience a reduction in the HVPG of 20% or greater or to lower than 12 mm Hg in response to β-blocker therapy have a markedly decreased risk of bleeding (or rebleeding), ascites, and spontaneous bacterial peritonitis, resulting in improved survival rates.