Acute mesentric ischemia
• Acute mesenteric ischemia is a
constant and severe decrease in
• Results from a compromised blood
supply, usually to the superior
(50% of cases): Almost
all emboli are of a
cardiac origin (e.g.,
atrial fibrillation, MI,
(25% of cases).
• Most of these patients have
atherosclerotic disease (e.g.,
coronary artery disease [CAD], PVD,
stroke) at other sites.
• Acute occlusion occurs over pre-
existing atherosclerotic disease. The
acute event may be due to a
decrease in cardiac output (e.g.,
resulting from MI, CHF) or plaque
• Collateral circulation has usually
Types of acute mesentric ischemia
(20% of cases).
• Splanchnic vasoconstriction
secondary to low cardiac
• Typically seen in critically ill
(<10% of cases).
• Many predisposing factors—infection,
hypercoagulable states, oral
contraceptives, portal HTN, malignancy,
Types of acute mesentric ischemia
• The overall mortality rate for all types of acute mesenteric
ischemia is about 60% to 70%. If bowel infarction has occurred,
the mortality rate can exceed 90%
1. Classic presentation is acute onset of severe abdominal pain
disproportionate to physical findings. Pain is due to ischemia and possibly
infarction of intestines, analogous to MI in CAD.
a. The abdominal examination may appear benign even when there is
severe ischemia. This can lead to a delay in diagnosis.
b. The acuteness and the severity of pain vary depending on the type of
acute mesenteric ischemia.
2. Anorexia, vomiting.
3. GI bleeding (mild). .
4. Peritonitis, sepsis, and shock may be present in advanced disease.
Differences in Presentation of Types of Acute
• Embolic—symptoms are more sudden and painful than other
• Arterial thrombosis—symptoms are more gradual and less
severe than embolic causes
• Nonocclusive ischemia—typically occurs in critically ill
• Venous thrombosis—symptoms may be present for several
days or even weeks, with gradual worsening
● Signs of intestinal infarction include hypotension, tachypnea,
lactic acidosis, fever, and altered mental status (eventually
leading to shock).
● Check the lactate level if acute mesenteric ischemia is
1. Mesenteric angiography is the definitive
2. Obtain a plain film of the abdomen to
exclude other causes of abdominal pain.
3. “Thumbprinting” can be seen on barium
enema due to thickened edematous
1. Supportive measures: IV fluids and broad-spectrum antibiotics
2. Direct intra-arterial infusion of papaverine (vasodilator) into the superior
mesenteric system during arteriography is the therapy of choice for all arterial
causes of acute mesenteric ischemia. This relieves the occlusion and vasospasm.
3. Direct intra-arterial infusion of thrombolytics or embolectomy may be indicated in
some patients with embolic acute mesenteric ischemia.
4. Heparin anticoagulation is the treatment of choice for venous thrombosis.
5. Surgery (resection of nonviable bowel) may be needed in all types of acute
mesenteric ischemia if signs of peritonitis develop.
Chronic mesenteric ishcemia
● Caused by atherosclerotic occlusive disease of main mesenteric vessels (celiac
artery, superior and inferior mesenteric arteries).
● Abdominal angina—dull pain, typically postprandial (when there is increased
demand for splanchnic blood flow); analogous to anginal pain of CAD. Significant
weight loss may occur due to abdominal angina.
● Mesenteric arteriography confirms the diagnosis.
● Surgical revascularization is definitive treatment and leads to pain relief in 90% of