Small Bowel Infarction:
Pathogenesis and clinical findings
Authors: Yan Yu Reviewers: Dean Percy Danny Guo Erin Stephenson Maitreyi Raman* * Indicates faculty member at time of publication
Important Notes:
• Bowel infarction is a rare cause of acute abdominal pain
• Small bowel infarction is more
common than colonic due to the small intestine’s single blood supply (SMA) versus the colon’s dual blood supply (SMA and IMA)
• With decreased perfusion colonic tissue tends to suffer from ischemia rather than more serious infarction
• Colonic ischemia presents with pain, diarrhea, and rectal bleeding
Abbreviations
• SMA – Superior mesenteric
artery
• IMA – Inferior mesenteric artery
Atrial fibrillation
Blood stasis in left atria of heart more
prone to coagulation
Embolism occluding SMA
Hypertension, dyslipidemia, smoking, diabetes, + family hx
Atherosclerosis (of SMA)
Thrombosis in the superior mesenteric artery
↓ Arterial perfusion of the small intestine (↓ O2 delivery to bowel tissue)
Ischemia of bowels Infarction of bowels
Venous trauma
↓ blood flow and endothelial injury
hypercoagulable state
Mesenteric venous thrombosis, backing up arterial blood
Food in the
intestine ↑ demand for blood in gut
Death of cells under visceral peritoneum stimulates autonomic nerves
Post-prandial abdominal pain
Severe central abdominal pain
Small bowel infarction from
SMA occlusion is commonly pain progressive, and out of proportion with the patient’s physical exam findings
Legend:
Pathophysiology
Mechanism
Sign/Symptom/Lab Finding
Complications
Re-Published June 15, 2019 on www.thecalgaryguide.com