Pediatric Superior Mesenteric Artery Syndrome

  • Etiology: Thin body habitus or recent severe weight loss or scoliosis surgery leads to superior mesenteric artery compressing third portion of the duodenum and causing obstruction as duodenum passes between superior mesenteric artery and aorta
  • Imaging UpperGI: Obstruction at duodenal horizontal limb over the spine by superior mesenteric artery leads to delayed emptying of stomach due to narrowing in third portion of duodenum
  • Imaging CT:
    — Superior mesenteric artery angle to aorta normally 45 degrees but in superior mesenteric artery syndrome is 6-25 degrees
    — Superior mesenteric artery to aorta distance normally 10-20 millimeters but in superior mesenteric artery syndrome is 2-8 millimeters
  • DDX:
  • Complications: Duodenal obstruction
  • Treatment: Feeding tube tip beyond ligament of Treitz to help patient gain weight to relieve obstruction
  • Clinical: Postprandial discomfort, bilious vomiting

Radiology Cases of Superior Mesenteric Artery Syndrome

Upper GI of superior mesenteric artery syndrome
Delayed AP image from an upper GI shows a markedly dilated first and second part of the duodenum to the right of the spine with a marked narrowing and transition in duodenal caliber over the spine and only a small amount of contrast in the third part of the duodenum to the left of the spine. During the exam, marked to and fro peristaltic motion was noted in the first and second parts of the duodenum.
UGI of superior mesenteric artery syndrome
AP image from an upper GI exam shows extremely dilated first and second portions of the duodenum. There was continuous to and fro motion of contrast in the duodenum and over 15 minutes no contrast passed across the spine and through the duodenal C-loop.
CT of superior mesenteric artery syndrome
Axial CT with contrast of the abdomen (above) shows the dilated stomach anteriorly in the abdomen and the dilated duodenum posterior to it on the right side of the abdomen that then tapers in diameter as it reaches the superior mesenteric artery in the midline above the spine. Coronal image (below) demonstrates the tremendously dilated nature of the stomach and duodenal bulb.