A 20-year-old woman with BMI 17 presents with recurrent episodes of postprandial vomiting and weight loss. Upper GI series shows abrupt vertical cutoff of the contrast in the third part of the duodenum with proximal dilatation. Normal aortomesenteric distance on CT is typically 10-28 mm. This patient likely has a narrowed aortomesenteric angle. What is the normal aortomesenteric angle?

• A 5-15 degrees
• B 25-60 degrees ✓
• C 70-90 degrees
• D 90-120 degrees

Explanation

Superior mesenteric artery (SMA) syndrome is caused by compression of the third part of the duodenum between the SMA and aorta due to loss of the protective fatty cushion. The normal aortomesenteric angle is 38-65 degrees (range 25-60 degrees), and the normal aortomesenteric distance is 10-28 mm. In SMA syndrome, the angle narrows to 6-15 degrees and distance reduces to 2-8 mm.

Reference: Sabiston Textbook of Surgery, 21st ed.

High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP

Written and medically reviewed by the StethoPrep medical team.