It usually reaches the inferior vena cava as a single vessel, but sometimes drains into it as two separate trunks.

[1]: 1213 The hepatic veins (and their variant anatomy) are relevant in liver resection and transplantation, and in Budd–Chiari syndrome.

[1] Budd–Chiari syndrome is a condition caused by blockage of the hepatic veins, such as by a blood clot.

It presents with a "classical triad" of abdominal pain, ascites, and liver enlargement.

[citation needed] The independent lower veins draining the liver segment I directly into the inferior vena cava are unaffected by obstruction of the large hepatic veins, leading to compensatory hypertrophy.