What Is HVPG and Why Does It Matter?

HVPG – Hepatic Venous Pressure Gradient – is the pressure difference between the wedged hepatic venous pressure (WHVP, a proxy for portal pressure) and the free hepatic venous pressure (FHVP). In a healthy liver, this gradient is 1-5 mmHg. As cirrhosis progresses and the liver’s internal resistance rises, portal pressure climbs.

The clinical thresholds are well defined. An HVPG ?6 mmHg confirms portal hypertension. At ?10 mmHg the portal hypertension becomes clinically significant (CSPH) – the point at which varices begin to form, splenomegaly worsens, and ascites may develop. At ?12 mmHg the risk of variceal rupture rises substantially. An HVPG ?20 mmHg within the first 24 hours of a variceal bleed predicts early re-bleeding and a five-fold increase in one-year mortality.

These numbers matter beyond diagnosis. When a patient starts non-selective beta-blockers (carvedilol or propranolol) for portal hypertension, a haemodynamic response is defined as either a ?20% reduction in HVPG from baseline, or an absolute reduction below 12 mmHg. Achieving this response halves the long-term risk of variceal bleeding. HVPG monitoring is the only way to confirm a true haemodynamic response – a pulse rate drop alone is not sufficient.

Who Needs an HVPG Measurement?

• Patients with cirrhosis and suspected portal hypertension where non-invasive staging (FibroScan, MRE, platelet count) is inconclusive
• Monitoring beta-blocker response in patients with medium/large varices or after a variceal bleed
• Pre-operative assessment before liver resection – surgeons need HVPG <10 mmHg to proceed safely
• Differentiating sinusoidal (cirrhosis, where HVPG is elevated) from pre-sinusoidal portal hypertension (non-cirrhotic portal fibrosis, where FHVP is low and HVPG may be normal despite portal hypertension)
• Prognostic staging in clinical trials or where precise pressure-guided management is planned

How Is the Procedure Performed?

HVPG is performed by a hepatologist or interventional radiologist under local anaesthesia, often with mild IV sedation for patient comfort. Access is obtained through the right internal jugular vein (or, less commonly, the femoral vein). A balloon-tipped catheter is advanced under fluoroscopic guidance into a branch of the hepatic vein.

Two pressure readings are taken. The free hepatic venous pressure (FHVP) is measured with the balloon deflated, recording the resting hepatic vein pressure. The wedged hepatic venous pressure (WHVP) is recorded with the balloon inflated, occluding the vessel – this creates a static column of blood communicating with the hepatic sinusoids and, through them, the portal venous system. HVPG = WHVP ? FHVP.

The procedure takes 30-60 minutes. Patients are observed for 2-4 hours post-procedure and can usually go home the same day. Normal activities can resume the next day.

Risks

HVPG is a low-risk procedure. The most common minor issue is local bruising or haematoma at the access site, occurring in under 3% of cases. Serious complications – hepatic vein perforation, haemobilia, arrhythmia – are rare with experienced operators. The procedure is contraindicated if the patient has severe coagulopathy (INR >2.5) or thrombocytopenia below 50,000/?L that cannot be corrected temporarily.