Marginal artery of Drummond
Branch
Continuous anastomotic arcade running along the mesenteric border of the whole colon, built from the ileocolic, right colic, middle colic, left colic and sigmoid arteries; short vasa recta leave it to the bowel wall. It is the main link between SMA and IMA territories. The arc of Riolan (meandering mesenteric artery) is a more central, inconstant middle colic–left colic shunt.
Traced from the start
- Abdominal aorta
- Superior mesenteric arteryInferior mesenteric artery
- Marginal artery of Drummond
Detail
- Formed by
- Ileocolic, right colic, middle colic, left colic and sigmoid arteries
- Weak points
- Splenic flexure (Griffiths' point) and rectosigmoid junction (Sudeck's point)
- Arc of Riolan
- Central middle colic ↔ left colic connection in ~7–10%; enlarges when SMA or IMA is stenosed
When it goes wrong
Hypotension, cardiac failure, dialysis, vasopressors or cocaine reduce flow through the arcade's narrowest segments
Non-occlusive ischaemic colitis at the splenic flexure and rectosigmoid (about 70% of cases): elderly patient with sudden cramping left-sided pain, urgency and bloody diarrhoea; CT 'thumbprinting'
Large tortuous 'meandering mesenteric artery' on CT angiography
Implies chronic occlusion of the SMA or IMA — the arc of Riolan has enlarged to carry the collateral load; do not sacrifice it at surgery
Practise this structure
1 question in the bank tagged Mesenteric Arterial Supply.