We discussed a case about a young woman with neuromyelitis optica, depression / anxiety, recent significant unintentional weight loss, who presented with acute abdominal pain (predominantly in the lower quadrants) and nausea (no vomiting). She was diagnosed with SMA syndrome. We reviewed the abdominal pain emergencies that should not be missed and discussed the pathophysiology + risk factors for + diagnosis + treatment of SMA syndrome.

What is SMA syndrome

• Loss of mesenteric fat pad between the aorta and SMA -> compression of duodenum -> proximal intestinal obstruction

Risk factors

• Significant weight loss due to medical / psychological disorders or surgery
• Anatomic abnormalities (congenital vs acquired)

Diagnosis

• Plain abdominal film, PO contrast studies, and/or CTA vs MRA

Imaging diagnostic criteria

• Duodenal obstruction w/ abrupt cutoff in the 3rd portion and active peristalsis
• Aortomesenteric artery angle of ≤25 degrees

Treatment

• Conservative
  • GI decompression, correct electrolyte abnormalities (watch for refeeding!), nutritional support (for weight gain)
• If conservative fails, surgical treatment
  • Strong’s procedure, gastrojejunostomy, duodenojejunostomy