The superior mesenteric vein is the major tributary of the portal vein. It’s created in the right iliac fossa by the joining of small veins coming from the ileocaecal region. It runs upward accompanying the superior mesenteric artery (the vein being right to the artery) and ends behind the neck of pancreas by joining the splenic vein to create the portal vein.

The tributaries of superior mesenteric vein are as follows:

  • Veins corresponding to the branches of superior mesenteric artery.
  • Right gastroepiploic vein.
  • Inferior pancreaticoduodenal vein.

The superior mesenteric vein empties venous blood from the small intestine that is rich in nutrients, large intestine up to the junction of proximal 2-third and distal one third of the transverse colon, stomach, and pancreas.