Mesenteric Ischemia and Infarction

First Things First (assess & treat for the following)

Make the diagnosis: The key to mgt is early diagnosis & treatment before irreversible ischemia occurs. The problem is that the early signs & symptoms of a devastating problem are often subtle, & routine tests are not sensitive or specific.

  • Diagnosis should be suspected on clinical grounds based on a high degree of suspicion. The differential diagnosis includes:
    • The most common causes of acute bowel ischemia are related to obstruction. About 33% of complete small bowel obstructions are complicated by strangulation due to mid-gut volvulus, adhesions or a incarcerated hernia. Consider:
      • Previous abdominal surgery
      • Hernia
      • History of congenital defects
    • The second most common cause of acute mesenteric ischemia is primary vascular occlusion due to hemorrhage into an existing mesenteric arterial atherosclerotic plaque w/ subsequent narrowing & thrombosis or to embolization of clot from a proximal site. Consider:
      • Atherosclerotic peripheral vascular disease
      • History of intestinal angina w/ dehydration
      • Atrial fibrillation
      • CHF
      • Recent cardiac catheterization, cardioversion or arteriogram
    • Traumatic disruption of 2 or more mesenteric vessels occasionally causes acute ischemia. A few pts experience slow progressive stenosis of 2 or more mesenteric arteries related to atherosclerosis or vasculitis. Consider:
      • Abdominal trauma
      • Recent abdominal surgery including aortic aneurysm repair, bowel resection, colostomy
    • Rarely, primary vascular occlusion is related to venous thrombosis precipitated by a hypercoagulable state, dehydration, portal hypertension & polycythemia. Consider:
      • History of thrombophlebitis
      • Recent portal vein surgery
      • Pregnancy
    • Finally, nonocclusive mesenteric ischemia is related to low-flow states of CHF, cardiac arrhythmias & aortic valve insufficiency, usually underlying profound splanchnic vasospasm in response to:
      • Shock
      • Sepsis
      • Respiratory insufficiency
      • Recent cardiopulmonary bypass
      • Recent hemodialysis
      • Administration of vasoconstrictors such as
        • Epinephrine
        • Digitalis
      • Cocaine abuse
  • Diagnosis is confirmed by angiography or laparotomy.

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Last updated: May 7, 2010