Which segment of the large bowel is most vulnerable to ischaemic injury following a period of systemic hypoperfusion, because it lies at the watershed between the territories of the superior and inferior mesenteric arteries?
- A Caecum
- B Splenic flexure ✓
- C Hepatic flexure
- D Rectum
Correct answer: B. Splenic flexure
Explanation
The splenic flexure, at Griffiths' point, sits between the terminal branches of the middle colic artery from the SMA and the left colic artery from the IMA, making it the classic watershed zone for non-occlusive ischaemic colitis. The caecum and ascending colon have rich collateral supply from the marginal artery. The rectum is almost never involved because it receives dual supply from the superior, middle, and inferior rectal arteries.
Reference: Bailey and Love Short Practice of Surgery, 27th ed.
High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP
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