How is the HVPG measured?
Access into the hepatic veins can be obtained via the more common transjugular approach or via a transfemoral approach.
A balloon occlusion catheter is placed into a hepatic vein 2 to 3 cm from the hepatic vein ostium and a free hepatic vein pressure (FHVP) measurement is obtained with the balloon deflated. A wedged hepatic vein pressure (WHVP) measurement is obtained with total occlusion of the hepatic vein on inflation of the balloon.
The HVPG is the difference between WHVP and FHVP.