The caudate lobe is a small lobe in the back portion of the liver. It can be found between the left lobe of the liver and the inferior vena cava (IVC), a large vein in the lower portion of the body that helps to transport deoxygenated blood to the right atrium in the heart. Blood supply can enter this lobe from either the left or right branches of the portal vein, which is a small vein for carrying blood into the liver. The caudate lobe sits in an almost vertical position.
Located opposite the middle of the vertebral column, the caudate lob is bound on the left by a fibrous material known as the ligamentum venosum. It is bordered in the bottom by a hole called the porta which leads into the body cavity. To the left, the caudate lobe is bordered by a concave surface called the fossa which separates the liver from the gall bladder.
There are five surfaces to the caudate lobe: the right plane, the ventral-border plane, the left surface, the hilar-free surface, and the dorsal. Many surgeons also recognize two distinct parts to this lobe: the Spiegel’s lobe and the paracaval portion. The Speigel’s lobe is located on the left and drains fluid from its bile ducts into either the right heptic duct or its branches. On the right, the paracaval portion of the lobe forms a flat plane that extends the length of the caudate lobe. There is not a distinct boundary between these two parts.
Unlike the liver's other lobes, the caudate lobe is directly connected to the IVC through small veins, known as heptic veins, which move deoxygenated blood. These veins are separate from the main heptic veins in the liver. For this reason, this lobe may respond to disease differently than the rest of the liver. Due to its unusual location, it may experience hypertrophy, which is an abnormal cell-based growth in tissue and organ, apart from the rest of the liver.
Some conditions that can cause hypertrophy include cirrhosis, congenital hepatic fibrosis, and Budd-Chiari syndrome. Cirrhosis is scarring of the liver due to liver disease. It is primarily caused by alcoholism. Congenital hepatic fibrosis is a genetic liver disease that mostly consists of tension in the portal veins, which lead to the caudate lobe. Budd-Chiari syndrome is an illness where the heptic veins are blocked thus impeding the flow of blood to the liver.