Mesenteric Ischemia

Introduction

• Mesenteric ischemia occurs due to reduced blood flow through mesenteric vessels, leading to intestinal ischemia.
• Can be studied further at Zero2Finals.com or in the Zero2Finals surgery book.

Blood Supply to Abdominal Organs

• Three main branches of the abdominal aorta:
  • Celiac Artery: Supplies the foregut (stomach, part of duodenum, biliary system, liver, pancreas, spleen).
  • Superior Mesenteric Artery: Supplies the midgut (distal part of duodenum to the first part of transverse colon).
  • Inferior Mesenteric Artery: Supplies the hindgut (second half of transverse colon to the rectum).

Chronic Mesenteric Ischemia

• Also known as intestinal angina.
• Caused by narrowing of mesenteric blood vessels via atherosclerosis.
• Symptoms:
  • Central colicky abdominal pain after eating (starts ~30 min after eating, lasts 1-2 hours).
  • Weight loss (due to food avoidance).
  • Abdominal bruit (whooshing sound from turbulent blood flow).
• Risk Factors:
  • Common cardiovascular risk factors: increased age, family history, smoking, diabetes, hypertension, raised cholesterol.
• Diagnosis:
  • CT angiogram with intravenous contrast to detect abnormalities.
• Management:
  • Reduce modifiable risk factors (e.g., stop smoking).
  • Secondary prevention with statins, antiplatelet medications.
  • Revascularization (endovascular procedures like mesenteric artery stenting, or open surgery like endarterectomy, reimplantation, or bypass surgery).

Acute Mesenteric Ischemia

• Typically caused by rapid blockage in the superior mesenteric artery.
• Causes:
  • Thrombus or embolus blocking blood flow.
  • Atrial fibrillation is a key risk factor (thromboembolism).
• Presentation:
  • Acute, non-specific abdominal pain.
  • Pain disproportionate to examination findings.
  • Potential progression to shock, peritonitis, and sepsis.
• Diagnosis:
  • Contrast CT scans.
  • Arterial blood gas shows metabolic acidosis with raised lactate (due to anaerobic respiration).
• Treatment:
  • Surgical intervention to remove necrotic bowel tissue and address thrombus.
  • High mortality rate (>50%).

Additional Resources

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