The superior mesenteric artery syndrome

Obstruction of the duodenum by entrapment between the aorta and the superior mesenteric artery (SMA) is a controversial entity. Acceptance of this syndrome as a clinical entity has not been universal because of confusion with other causes of upper gastrointestinal obstruction. Two cases which sharply exemplify the clinical and anatomic features of the SMA syndrome are reported. Symptoms mimic pyloric outlet obstruction but gastroscopy is frequently normal and the diagnosis is made on barium studies. The anatomic features of this entity are a narrow angle between the aorta and the SMA, together with high fixation of the duodenum by the ligament of Treitz. The SMA syndrome may be acute or chronic and responds well to duodeno­ jejunostomy.