superior mesenteric vein
Origin and course
Mesenteric venous arcades, which accompany the arteries, unite to form the jejunal and ileal veins in the small bowel mesentery and are joined by the tributaries listed below. Often the superior mesenteric vein is considered the common trunk after all the chief tributaries have joined.
The gastrocolic trunk drains into the right-hand aspect of the SMV just anterior to the uncinate process of the pancreas. It unites with the splenic vein posterior to the neck of the pancreas (at the level of L1) to form the portal vein.
The SMV is accompanied by the SMA and normally lies to the right. If it is not in this position, it can indicate intestinal malrotation.
- anterior: neck of pancreas
- posterior: uncinate process of pancreas
- mesenteric venous arcades (jejunal and ileal veins)
- ileocolic vein
- right colic vein
- inferior pancreaticoduodenal vein
- gastrocolic trunk
- right gastroepiploic vein
- middle colic vein
- anterior superior pancreaticoduodenal vein
- absence of common draining trunk with two "intestinal trunks" draining directly into the splenic vein (~10%)
- variations in the formation of the portal vein