Superior Mesenteric Artery Obstruction of the Duodenum

• • Obstruction of the third portion of the duodenum by compression between the superior mesenteric vessels and the aorta

Epidemiology

• • Most commonly appears after rapid weight loss following injury or burns

  • Acute loss of mesenteric fat is thought to permit the artery to drop posteriorly, trapping the bowel like in a pair scissors

Symptoms and Signs

• • Epigastric bloating

  • Crampy pain relieved by vomiting

  • Symptoms may remit in the prone position

  • Anorexia and postprandial pain lead to additional malnutrition and weight loss

Imaging Findings

• • Upper GI contrast radiography

  • -Demonstrates a widened duodenum proximal to a sharp obstruction where the artery crosses the third portion of the duodenum, as well as increased duodenal peristalsis proximal to the arterial blockage

    -When the patient moves to the knee-chest position, the passage of contrast material is suddenly unimpeded

  • Angiography

  • -Shows an angle of 25 degrees or less between the superior mesenteric artery and the aorta

    -Not recommended for routine evaluation of obvious cases

• • Onset of epigastric bloating and crampy pain relieved by vomiting following rapid weight loss should be evaluated by upper GI contrast radiography

Rule Out

• • Intestinal malrotation with duodenal obstruction by congenital bands

  • Involvement of the duodenum by scleroderma with diminished duodenal peristalsis

• • Signs and symptoms consistent with duodenal obstruction, particularly in the setting of rapid weight loss should prompt upper GI contrast radiography

  • Upper GI contrast radiography will confirm the diagnosis in most cases

When to Admit

• • High-grade obstruction with vomiting and inability to tolerate enteral nutrition

  • Severe abdominal pain

• • Postural therapy may suffice

  • -The patient should be placed prone in the knee-chest position when symptomatic or in anticipation of postprandial difficulties

Surgery

Indications

• • Chronic obstruction: Division of suspensory ligament and mobilization of duodenum, or duodenojejunostomy

  • Malrotation: Mobilization of the

  • duodenojejunal flexure

Prognosis

• • Surgical correction produces good long-term results

References