Measurement of Portal Pressure and Its Application in the Clinical Setting

Introduction Portal hypertension is a severe, yet common sequela of patients with chronic liver disease and is responsible for many of the complications seen in this population. Measurement of the hepatic venous pressure gradient (HVPG) is the current gold-standard technique for identifying and evaluating the severity of portal hypertension. Any increase in HVPG to ≥10 mm Hg is considered clinically significant portal hypertension. Above this threshold, complications of portal hypertension begin to manifest. In addition to assessing portal hypertension, various HVPG thresholds have been shown to have strong prognostic value for risk of complications and therapeutic failure, as well as survival in patients with chronic liver disease. These clinical applications include quantification of disease progression and regression in chronic viral hepatitis, acute alcoholic hepatitis, and hepatocellular carcinoma. Other applications include preoperative evaluation of liver resection and transplantation in patients with cirrhosis and hepatocellular carcinoma, assessment of response to therapy for portal hypertension, and identification of the need for transjugular intrahepatic portosystemic shunt (TIPS) revision.

Content Organization We will discuss the technique, complications, indications, and contraindications for measurement of HPVG. Then, we will describe the diagnosis and classification of portal hypertension as it relates to clinical application of HPVG. Additionally, we will review the utilization of HPVG for assessment of disease severity in those with chronic liver disease, as well as using HPVG to monitor response to therapy for portal hypertension. Finally, we will cover the endoscopic assessment of varices and their clinical applications in relation to HPVG, as well as describe the limitations of HPVG measurement.

Learning Points Measurement of HVPG is a safe, simple, and largely reproducible study that remains the gold standard for quantifying portal pressure. It is also currently the best surrogate marker for outcomes in patients with chronic liver disease, as it reflects disease severity and provides strong prognostic value on risk of complications and failure of therapy, as well as survival in this population. Its clinical applications in hepatology and interventional radiology are broad. Thus, it is important for clinicians to be familiar with the procedure for measuring HVPG, as well as the interpretation of the results and their clinical implications.