Inferior mesenteric vein
Tributary · Hindgut
Begins as the superior rectal vein from the rectal venous plexus, receives the sigmoid and left colic veins, and ascends in the retroperitoneum to the left of the inferior mesenteric artery, raising the paraduodenal fold just to the left of the duodenojejunal flexure. It passes behind the body of the pancreas and classically ends in the splenic vein, although in practice it ends in the splenic vein, the superior mesenteric vein or their junction in roughly comparable proportions.
Detail
- Drains
- Hindgut: upper rectum, sigmoid and descending colon, splenic flexure
- Begins as
- Superior rectal vein, the portal limb of the rectal anastomosis
- Termination
- Splenic vein (classical), or superior mesenteric vein or splenoportal junction
- Relation
- Left of the inferior mesenteric artery; in the paraduodenal fold beside the duodenojejunal flexure
When it goes wrong
Haematogenous spread of colon and upper rectal carcinoma
Tumour emboli reach the liver first via the inferior or superior mesenteric vein and portal vein, so the liver is the usual first site of distant metastasis
Left paraduodenal (Landzert) hernia, with the inferior mesenteric vein and ascending left colic artery in the free edge of the sac
Recurrent small-bowel obstruction; the neck must be opened away from the vein to avoid heavy bleeding when the bowel is released
Practise this structure
1 question in the bank tagged Hindgut.