Superior Mesenteric Artery (SMA) Syndrome Clinical Presentation

Updated: Dec 31, 2018
  • Author: Frederick Merrill Karrer, MD, FACS; Chief Editor: Carmen Cuffari, MD  more...
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The patient often presents with chronic upper abdominal symptoms such as abdominal pain, nausea, eructation, voluminous vomiting (bilious or partially digested food), postprandial discomfort, early satiety, and sometimes, subacute small bowel obstruction. Symptoms of superior mesenteric artery (SMA) syndrome often develop from 6-12 days after scoliosis surgery.

The symptoms are typically relieved when the patient is in the left lateral decubitus, prone, or knee-to-chest position, and they are often aggravated when the patient is in the supine position. These maneuvers are thought to reduce the small bowel mesenteric tension at the aortomesenteric angle. [11]



An asthenic habitus is noted in about 80% of cases. Abdominal examination may reveal a succussion splash. Peptic ulcer disease has been noted in 25-45% of the patients, and hyperchlorhydria has been noted in 50%. Patients can present with signs of subacute small bowel obstruction.



Important etiologic factors that may precipitate narrowing of the aortomesenteric angle and recurrent mechanical obstruction include the following:

  • Constitutional factors

    • Thin body build

    • Exaggerated lumbar lordosis

    • Visceroptosis and abdominal wall laxity

    • Depletion of the mesenteric fat caused by rapid severe weight loss due to catabolic states such as cancer, surgery, burns, trauma, or psychiatric problems

  • Severe injuries, such as head trauma, leading to prolonged bedrest

  • Dietary disorders

  • Spinal disease, deformity, or trauma (use of body cast in the surgical treatment of scoliosis or vertebral fractures): Superior mesenteric artery syndrome cases after corrective spine surgery are due to the result of spinal elongation, which decreases the superior mesenteric/aortic angle. Postoperative weight loss is an important factor for development of superior mesenteric artery syndrome. Although use of Harrington rods for corrective surgery commonly used in the 1950s and 1960s was an important contributory factor for development of superior mesenteric artery syndrome, newer derotation/translation corrective techniques can also rarely be associated with this disease entity. [12]

  • Rapid linear growth without compensatory weight gain, particularly in adolescents: Adolescents with low body mass index (< 18 kg/m2) may be at higher risk for developing superior mesenteric artery syndrome after spinal fusion for scoliosis than patients with a higher body mass index. [13]

  • Anatomic anomalies (rare)

    • Abnormally high and fixed position of the ligament of Treitz with an upward displacement of the duodenum

    • Unusually low origin of the superior mesenteric artery

  • Unusual causes

    • Traumatic aneurysm of the superior mesenteric artery after a stab wound

    • Abdominal aortic aneurysms and mycotic aortic aneurysms [14]

    • Familial superior mesenteric artery syndrome

    • Recurrent superior mesenteric artery syndrome

    • Idiopathic neonatal superior mesenteric artery syndrome [15, 16]