Superior mesenteric vein

Confluence · Midgut Foregut

Ascends in the root of the mesentery to the right of the superior mesenteric artery, crossing in front of the third part of the duodenum and the uncinate process of the pancreas, and ends behind the neck of the pancreas by joining the splenic vein. It drains the whole midgut together with part of the stomach, duodenum and pancreas.

Traced from the start

  1. Jejunal, ileal, ileocolic, right colic and middle colic veinsRight gastro-omental and pancreaticoduodenal veins
  2. Superior mesenteric vein

Detail

Relation
Right of the superior mesenteric artery; anterior to the third part of the duodenum and the uncinate process
Drains
Midgut plus right gastro-omental and pancreaticoduodenal territories
Ends
Behind the neck of the pancreas, uniting with the splenic vein

When it goes wrong

Mesenteric venous thrombosis (thrombophilia, oral contraceptive, pancreatitis, cirrhosis, malignancy)

Subacute abdominal pain out of proportion to the examination, then bloody diarrhoea and bowel infarction; diagnosed on contrast CT and treated with anticoagulation

Streaming of superior mesenteric blood preferentially into the right portal branch

Traditionally invoked to explain why pyogenic and amoebic liver abscesses and colorectal metastases favour the right lobe

Practise this structure

1 question in the bank tagged Small Bowel.