“Acute mesenteric ischaemia is one of the true surgical emergencies. Every hour of delay is intestine that cannot be saved. Speed of diagnosis and speed of revascularisation are everything.”
Written by Dr Rahul Agarwal, Consultant Vascular & Endovascular Surgeon
CARE Hospitals, Banjara Hills, Hyderabad
The gut needs blood to survive. The superior mesenteric artery (SMA) and inferior mesenteric artery (IMA) supply the small and large intestine. When blood flow through these vessels is suddenly reduced or stopped — mesenteric ischaemia — the intestine begins to die within hours. This is one of the most dangerous conditions in vascular surgery.
🦠 Acute vs Chronic Mesenteric Ischaemia
Acute Mesenteric Ischaemia
A sudden, catastrophic reduction in gut blood supply. Causes include arterial embolism (clot from the heart lodging in the SMA — common in patients with atrial fibrillation), arterial thrombosis on pre-existing atherosclerosis, venous thrombosis, and non-occlusive mesenteric ischaemia (from severe shock or low-flow states).
The hallmark is pain out of proportion to examination — the patient is in extreme pain, but the abdomen may initially feel soft with no peritonism. This is the diagnostic trap. By the time the abdomen becomes rigid and board-like, significant bowel has already died.
Chronic Mesenteric Ischaemia
Gradual narrowing of the mesenteric arteries causing “gut claudication” — pain that comes on 20–30 minutes after eating and lasts for 1–2 hours. Patients develop “food fear” and lose significant weight. This is an atherosclerotic condition, common in older patients with cardiovascular risk factors.
🚨 Warning Signs
- Sudden, severe, central abdominal pain (especially in a patient with atrial fibrillation)
- Pain disproportionate to abdominal findings
- Rapid deterioration with nausea, vomiting, and bloody diarrhoea
- Post-meal abdominal pain with weight loss (chronic form)
🔬 Diagnosis
- CT Angiography — The investigation of choice in acute mesenteric ischaemia. Fast, widely available, shows both the mesenteric vessels and bowel viability.
- Duplex Ultrasound — Useful for chronic mesenteric ischaemia screening; less reliable in acute settings.
- Laboratory markers — Raised lactate, white cell count, and metabolic acidosis suggest advanced bowel ischaemia.
💉 Treatment
For acute mesenteric ischaemia, treatment is a surgical emergency. Options include open embolectomy or thrombectomy, intestinal bypass, or increasingly endovascular revascularisation (catheter-directed thrombolysis or stenting) — followed by assessment of bowel viability and resection of any non-viable intestine. ICU care is mandatory post-operatively.
For chronic mesenteric ischaemia, endovascular stenting of the mesenteric artery is the first-line treatment in most centres, providing excellent results with minimal recovery time. Open surgical bypass is reserved for complex anatomy or failed endovascular treatment.
💡 Key Insight: In a patient with atrial fibrillation who develops sudden, severe abdominal pain — think SMA embolism until proven otherwise. This is not a condition to “watch and wait.” CT angiography and immediate vascular surgery involvement are mandatory.
📖 Related Reading:
- Aortic Aneurysm: The Silent Time Bomb
- When Should You See a Vascular Surgeon?
- What Is Vascular Surgery? The Complete Guide
About the Author 🧑🏻⚕️
Dr Rahul Agarwal is a Consultant Vascular & Endovascular Surgeon at CARE Hospitals, Banjara Hills, Hyderabad.