Inferior mesenteric vein

Structure

The inferior mesenteric vein merges with the splenic vein, posterior to the middle of the body of the pancreas. The splenic vein then merges with the superior mesenteric vein to form the portal vein.

Tributaries

Tributaries of the inferior mesenteric vein drain the large intestine, sigmoid colon and rectum. These include:

• left colic vein
• sigmoid veins
• superior rectal vein
• rectosigmoid veins

Variation

Anatomical variations include the inferior mesenteric vein draining into the confluence of the superior mesenteric vein and splenic vein and the inferior mesenteric vein draining in the superior mesenteric vein.