Portal pressure monitoring—state-of-the-art and future perspective

Portal hypertension (PH), a severe symptom of chronic liver diseases, is defined as a pathologically increased portal pressure gradient (PPG) greater than 5 mmHg (1). Measuring the hepatic perfusion pressure, PPG is the difference between the portal vein pressure (PVP) and hepatic vein pressure or inferior vena cava (IVC) pressures. It is caused by the interaction of the portal blood ？ow with the vascular resistance against the ？ow (2). The relationship can be given by Ohm’s law as follows