1. Portal vein is low resistance, low pressure system
2. Direct portal vein pressure is difficult to measure so clinically portal vein pressure is measured by HVPG, hepatic venous pressure gradient
HVPG is measured by cannulating the hepatic veins in liver through jugular or femoral vein
HVPG=
Wedged hepatic vein pressure.-- Free hepatic vein pressure
How is it measured clinically??
HVPG is measured by introducing a 7-French balloon-tipped catheter into the right or middle hepatic vein under fluoroscopic guidance. The free hepatic venous pressure (FHVP) is measured with the catheter ‘free’ in the hepatic vein, and the wedged hepatic venous pressure (WHVP) is measured following occlusion by the inflated balloon.
Values of HVPG and clinical significance