PED Case 6: Superior Mesenteric Artery Syndrome

Dennis Gilroy, MD

URMC Department of Imaging

Publication Date: 20170629

History

Patient is a 15-year-old female who had been healthy up until 1 year ago when she presented with spontaneous bilateral pneumothoraces and was diagnosed with idiopathic pulmonary fibrosis with respiratory failure requiring tracheostomy and chronic ventilation along with a period of time on ECMO, fibroproliferative ARDS, deconditioning and malnutrition. She had a prolonged ICU stay and was eventually discharged to a 2 month acute rehab program and then was discharged to home. She now presents with 1 day history of abdominal pain and projectile vomiting. Currently afebrile but recently recovered from viral upper respiratory infection (URI).

Findings

Axial (Fig. 1A), coronal (Fig. 1B), and sagittal (Fig. 1C) CT images demonstrate markedly distended stomach and proximal duodenum to the level of the third portion, in the midline. The sagittal image demonstrates acute angulation between the origin of the SMA and the aorta with apparent compression upon the duodenum, compatible with SMA syndrome. UGI study reveals similar findings with slow movement of contrast past the third portion of the duodenum (Fig. 2) and significant retention of contrast in the stomach on delayed images (Fig. 3).

Diagnosis

Superior Mesenteric Artery Syndrome

Discussion

SMA syndrome is a vascular compression syndrome involving the origin of the SMA off the aorta and its relationship to the third portion of the duodenum.

Presentation classically consists of dilated proximal duodenum and stomach with symptoms of small bowel obstruction, particularly after eating.

Some sources define the presence as an Aorto-SMA angle of <22-25 degrees and a decrease in aortomesenteric distance <10 mm.

Patients with weight loss are at risk as the retroperitoneal fat is depleted and the angle between the SMA and aorta becomes narrowed. Predisposing factors include hypercatabolic states(as in this case), malabsorption, anorexia nervosa.

Comments

References

  1. Fong JK, Poh AC, Tan AG, Taneja R. “Imaging Findings and Clinical Features of Abdominal Vascular Compression Syndromes.” AJR Am J Roentgenol 2014 Jul;203(1):29-26. PMID: 24951193 DOI: 10.2214/AJR.13.11598
  2. Roy A, Gisel JJ, Roy V, Bouras EP . “Superior mesenteric artery (Wilkie’s) syndrome as a result of cardiac cachexia.” J Gen Intern Med 2005 Oct;20(10):C3-4. PMID: 16191148 PMCID: PMC1490234 DOI: 10.1111/j.1525-1497.2005.0201.x
  3. https://my.statdx.com/document/sma-syndrome/af90f2fa-3050-4211-a191-b2677d735d6b?searchTerm=SMA%20Syndrome.

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