What is the treatment for Superior Mesenteric Artery (SMA) syndrome, also known as Six Pocket Syndrome?

Treatment of Superior Mesenteric Artery (SMA) Syndrome

Surgical intervention with laparoscopic duodenojejunostomy is the most effective treatment for SMA syndrome when conservative management fails, with success rates of 80-100%. 1

Understanding SMA Syndrome

SMA syndrome (also known as Wilkie's syndrome, cast syndrome, or aortomesenteric compass syndrome) is a rare form of intestinal obstruction characterized by:

• Compression of the third portion of the duodenum between the abdominal aorta and the superior mesenteric artery 1, 2
• Typically occurs in young adults with a median age of 23 years, with female predominance (3:2 ratio) 1
• Often associated with significant weight loss, which decreases the aortomesenteric angle to less than 25 degrees and reduces the aortomesenteric distance to less than 8 mm 3

Clinical Presentation

Patients with SMA syndrome typically present with:

• Postprandial abdominal pain 1, 2
• Nausea and vomiting (often bilious) 2
• Early satiety and food aversion 2
• Weight loss, creating a vicious cycle that worsens the condition 2
• Symptoms that can mimic anorexia nervosa or functional dyspepsia 1

Diagnostic Approach

Diagnosis of SMA syndrome requires:

• CT angiography (gold standard) to demonstrate vascular compression of the duodenum and measure the aortomesenteric angle and distance 1, 2
• Ultrasonography, which offers advantages in safety and capability for real-time assessment of SMA mobility and duodenal passage 1
• Exclusion of other causes of proximal bowel obstruction 2

Treatment Algorithm

1. Initial Conservative Management (First-Line)

Conservative measures should be attempted first, with success rates of 70-80% 1:

• Postural changes (left lateral decubitus or prone position after eating) 1, 2
• Gastroduodenal decompression via nasogastric tube 1, 2
• Nutritional support:
  • Small, frequent meals 2
  • Hyperalimentation or parenteral nutrition if needed 2
  • Nutritional counseling to promote weight gain 4

2. Surgical Management (When Conservative Treatment Fails)

Surgical intervention is indicated when:

• Conservative measures fail 5, 1
• Symptoms are severe or recurrent 5
• The duodenum is significantly compromised 2

Preferred surgical approach:

• Laparoscopic duodenojejunostomy is the procedure of choice 5, 1
  • Minimally invasive with good visualization of structures
  • Relatively short surgical time
  • Fast post-operative recovery
  • Particularly beneficial for patients in depleted health conditions
  • High success rates (80-100%)

3. Post-Treatment Follow-up

• Regular monitoring of nutritional status and weight gain 4
• Assessment for symptom recurrence 2
• Management of any underlying conditions that contributed to weight loss (e.g., anorexia nervosa, substance abuse) 3

Special Considerations

• In pediatric patients, delay in diagnosis may lead to significant morbidity and mortality across several age groups 4
• Patients with underlying conditions like anorexia nervosa or substance abuse require comprehensive treatment of these conditions to prevent recurrence 3
• The condition may exhibit a subclinical course in some patients, leading to symptomatic rather than definitive treatment 4

Pitfalls to Avoid

• Misdiagnosing SMA syndrome as functional dyspepsia or anorexia nervosa, delaying appropriate treatment 1
• Failing to address the underlying cause of weight loss, which can lead to recurrence 3
• Relying solely on conservative management for severe or recurrent cases, which may prolong suffering and worsen nutritional status 5, 2