Overview

Blood leaves the liver through a chain of veins. The sinusoids drain into a central vein at the centre of each lobule. Central veins join to form sublobular veins, which merge into the three main hepatic veins. These empty into the IVC just below the diaphragm. Several small veins from the caudate lobe drain separately and directly into the IVC.

The hepatic veins run between the liver segments, while the portal triads run inside them. The middle hepatic vein lies in the plane between the right and left halves of the liver (Cantlie's line). The right hepatic vein separates the anterior and posterior segments of the right half, and the left hepatic vein separates the medial and lateral parts of the left half. The hepatic veins have no valves.

Function

Drain all blood leaving the liver, about 1.5 L/min, into the IVC.

Clinical significance

Budd–Chiari syndrome

Budd–Chiari syndrome is obstruction of the hepatic veins or the hepatic part of the IVC. Causes include myeloproliferative disorders (for example JAK2-positive polycythaemia vera), thrombophilia and the contraceptive pill. It causes the triad of abdominal pain, ascites and liver enlargement. The caudate lobe drains directly into the IVC, so it escapes congestion and enlarges.

Congestive hepatopathy

In right heart failure and constrictive pericarditis, raised venous pressure is transmitted back into the liver. The centres of the lobules become congested, giving the cut liver a speckled "nutmeg" appearance.

Portal pressure measurement and TIPS

A catheter wedged into a hepatic vein measures the hepatic venous pressure gradient, which estimates portal pressure. A TIPS (transjugular intrahepatic portosystemic shunt) is a stent placed through the liver from a hepatic vein to a portal vein branch, to lower portal pressure.

Compiled from standard anatomy and physiology references — see the Cardiovascular System sources. For education only; not medical advice.