Splenic vein

At a glance

English

Splenic vein

Latin (TA2)

Vena splenica

System

Vein

Region

Trunk

Side

Single, on the midline

About the splenic vein

The splenic vein, once called the lienal vein, carries blood from the spleen, the upper part of the stomach and much of the pancreas towards the liver. It is one of the two main roots of the hepatic portal vein and a key vessel of the portal system.

It is formed at the hilum of the spleen by several veins that emerge from the organ, often five or six, which unite within the splenorenal ligament. From there it runs to the right across the posterior abdominal wall, behind the body and tail of the pancreas, often lying in a groove on the back of the gland. It travels below the splenic artery, which follows a more winding course along the upper border of the pancreas. On its way it crosses in front of the left kidney and left suprarenal gland, and then in front of the superior mesenteric artery and the aorta. Behind the neck of the pancreas it meets the superior mesenteric vein, and the portal vein begins from their union.

It collects the short gastric veins from the fundus of the stomach, the left gastro-omental vein from the greater curvature, and many small pancreatic veins. Its largest tributary is usually the inferior mesenteric vein, which joins it shortly before its end and brings blood from the left half of the large intestine. In some people the inferior mesenteric vein ends at the confluence or in the superior mesenteric vein instead.

Because the vein is closely applied to the pancreas, inflammation of that gland is the commonest cause of splenic vein thrombosis, whether the pancreatitis is acute or chronic. A clot here produces a local form of portal hypertension, sometimes called left-sided or sinistral portal hypertension: blood from the spleen is diverted through the short gastric veins, which swell into varices in the stomach wall and may bleed, often with abdominal pain and an enlarged spleen. Removing the spleen cures the problem by taking away the inflow. The vein must also be carefully separated from the pancreas during distal pancreatectomy, and it is used to create shunts that lower portal pressure.

Course and drainage

Begins at

Formed at the hilum of the spleen by the union of several splenic veins within the splenorenal ligament.

Drains into

Runs to the right behind the pancreas to join the superior mesenteric vein behind the pancreatic neck, forming the hepatic portal vein.

Drains

Drains the spleen, the fundus and greater curvature of the stomach, the pancreas and, through the inferior mesenteric vein, the left part of the large intestine.