Ischaemic Colitis Post-Aortic Surgery — FRCA Final MCQ

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ModeratePerioperative MedicineIschaemic Colitis Post-Aortic SurgeryFRCA Final

A 65-year-old man (ASA III) undergoes an open abdominal aortic aneurysm repair. Post-operatively in ICU he passes bloody diarrhoea. His lactate rises from 2.0 to 8.5 mmol/L and he develops metabolic acidosis. What is the most likely complication?

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Correct answer: A — Ischaemic colitis

Ischaemic colitis is a recognised complication of aortic surgery, occurring when the inferior mesenteric artery (which supplies the left colon) is ligated or its flow compromised during repair. It presents with bloody diarrhoea, rising lactate, and metabolic acidosis within 24-48 hours. Diagnosis is confirmed by flexible sigmoidoscopy showing mucosal ischaemia. Mild cases may be managed conservatively; severe cases with transmural necrosis require surgical resection. Incidence is 2-7% after elective AAA repair and higher after emergency/ruptured repair.

Reference: RCOA – 2023 – Vascular anaesthesia module; NICE – 2020 – AAA management