SMA syndrome

Background

• Full name: Superior Mesenteric Artery Syndrome
  • AKA: Wilke's syndrome
• Rare condition
• 1st described by Von Rokitansky in 1861 and then further studied in detail by Wilke in 1912
• Occurs when the duodenum is compressed between the aorta and the superior mesenteric artery, level of the third portion of the duodenum
• Can lead to chronic intermittent or acute, partial or complete gastrointestinal obstruction at the level of the duodenum
• Controversy over this diagnosis

Etiology

• SMA takes off from the abdominal aorta surrounded by fatty and lymphatic tissue also known as the mesenteric pad
• The mesenteric pad helps the SMA form an angle of about 45 degrees with the abdominal aorta
• Third part of the duodenum courses between the angle formed
• Narrowing of this angle can cause entrap and compress of the duodenum
  • Factors that narrow this angle include:
    • Significant weight loss, most common factor
    • Corrective spinal surgery for scoliosis lengthens the spine
    • Congenital defects, suggested genetic predisposition
    • Abdominal adhesions

Clinical Features

• Early satiety
• Nausea and vomiting, can be bilious
• Abdominal pain, mid-abdomen which may be improved with changes of position
• Abdominal bloating, especially after meals
• Bleching
• Weight loss
• Proximal small bowel obstruction

Differential Diagnosis

• See Abdominal Pain
• See Nausea and vomiting

Evaluation

• Suspected based on signs and symptoms
• Diagnosis confirmed by imaging:
  • Upper GI series
  • Upper endoscopy
  • Computed tomography

Management

• Primary goal is to correct the underlying cause, typically regain lost weight
• Acute treatment includes:
  • Adjusting body position to alleviate symptoms such as knee to chest or lying on left side
  • Nasogastric decompression
  • Some patients may require a feeding tube distal to the obstruction or parenteral nutrition
• Surgery may be required, options include:
  • Strong's procedure: duodenum moved to the right of the SMA
  • Gastrojejunostomy
  • Duodenojejunostomy

Disposition

• Depending on the clinical presentation
• If complete obstruction, may require admission for decompression and nutrition
• Outcome excellent with early diagnosis and appropriate treatment

See Also

Acute gastric dilation

References

• 1. <Karrer FM. Superior Mesenteric Artery Syndrome. Medscape Reference. Jan 2017; http://emedicine.medscape.com/article/932220-overview.>
• 2. <Pleoa A, Constantinescu C, Crumpei F, and Cotea E. Superior mesenteric artery syndrome: an unusual cause of intestinal obstruction. "J Gastrointest Liver Dis". Mar 2006; 15(1): 69-72.>
• 3. <Lorentziadis M. Wilke's syndrome. A rare cause of duodenal obstruction. "Ann Gastroenterol." 2011; 24(1): 59-61.