Treat Abdominal Pain Out of Proportion To Physical Exam as Mesenteric Ischemia Until Proven Otherwise
D. Joshua Mancini MD
Rajan Gupta MD
Acute mesenteric ischemia is an abdominal emergency with high mortality and devastating morbidity. Perioperative mortality is 20% to 80%, depending upon the etiology of the acute process, and the overall mortality rate remains above 60%. In acute mesenteric ischemia, initial tissue injury occurs as a result of compromised end-organ perfusion. Secondary injury at the cellular level likely occurs through amplification of an inflammatory response with free-radical generation during reperfusion. Acute mesenteric ischemia is usually divided into four categories, based upon etiology. Arterial embolism is the most common type and represents 40% to 50% of all acute mesenteric ischemia cases. Emboli most commonly originate from a cardiac source and occlude the superior mesenteric artery (SMA). Acute mesenteric arterial thrombosis accounts for 25% to 30% of acute mesenteric ischemia. The proximal SMA is the most common site of thrombosis. Nonocclusive mesenteric ischemia represents approximately 20% to 30% of the acute mesenteric ischemia cases. This condition is usually a result of relative hypovolemia, low cardiac output, and splanchnic vaso-constriction. Mesenteric vein thrombosis is the least common cause of acute mesenteric ischemia, accounting for approximately 5% to 10% of the cases. These cases are often associated with a concomitant intra-abdominal process such as malignancy or inflammation, or with primary clotting disorders such as factor V Leiden mutation.
Signs and Symptoms
Diagnosis of acute mesenteric ischemia may be difficult because the signs and symptoms often mimic other intra-abdominal processes. This often results in significant delays in diagnosis, especially in the intensive care unit (ICU). Because these delays can adversely affect outcome, heightened clinical suspicion is paramount. The four types of acute mesenteric ischemia present with different patterns of signs and symptoms. An embolic event usually causes a sudden onset of symptoms, while acute mesenteric ischemia due to thrombosis may present suddenly or with a progressive history
of postprandial pain, nausea, and weight loss. Nonocclusive mesenteric ischemia presents less acutely and often occurs in elderly patients in the ICU suffering from global hypoperfusion. Patients with mesenteric vein thrombosis classically present late with previous symptoms of nonspecific abdominal pain, anorexia, and diarrhea.
of postprandial pain, nausea, and weight loss. Nonocclusive mesenteric ischemia presents less acutely and often occurs in elderly patients in the ICU suffering from global hypoperfusion. Patients with mesenteric vein thrombosis classically present late with previous symptoms of nonspecific abdominal pain, anorexia, and diarrhea.