portosystemic gradient; hepatic venous pressure gradient (HVPG)

Introduction

In reference to the pressure gradient between the portal vein & the inferior vena cava.

Pathology

• cirrhosis of the liver impedes blood flow from the portal vein into the liver, resulting in a high pressure system in the portal vein
• increased accessory pathway use leads to esopageal varices & gastric varices

Reference interval

• < 10 mm Hg is normal

Clinical significance

• major factor in the development of esophageal varices
• > 20 mm Hg predicts poor outcome after hemorrage

More general terms

• pressure gradient