What is the recommended treatment for median arcuate ligament (MAL) syndrome?

Treatment for Median Arcuate Ligament Syndrome

Surgical release of the median arcuate ligament is the recommended first-line treatment for median arcuate ligament syndrome, with additional revascularization procedures considered when residual stenosis exceeds 30%. 1, 2

Diagnosis and Clinical Presentation

• Median arcuate ligament syndrome (MALS) presents with postprandial abdominal pain, nausea, vomiting, and weight loss due to compression of the celiac artery by the median arcuate ligament 1, 2
• Diagnosis is typically made through a combination of clinical findings and imaging, including CT angiography showing proximal narrowing of the celiac artery in a "J-shaped" configuration 1, 2
• Mesenteric angiography with lateral views during both inspiration and expiration can demonstrate dynamic worsening of stenosis on expiration, which is characteristic of MALS 1

Treatment Algorithm

First-Line Approach

• Initial supportive treatment with analgesics and continued diagnostic evaluation for alternate causes of abdominal pain is reasonable as first steps in suspected MALS 1, 2
• Surgical release of the median arcuate ligament is associated with symptomatic relief in 84.6% of patients and is the recommended definitive treatment 1

Secondary Interventions

• After surgical release, if residual stenosis of the celiac artery is >30%, additional revascularization may be necessary 1, 2
• Options for revascularization include:
  • Endovascular stent placement 1
  • Surgical bypass creation 1
  • Primary reanastomosis or interposition grafting 1

Treatment Outcomes

• Combined approach of celiac decompression with revascularization when needed results in complete resolution of symptoms in 75% of patients at 6 months 1
• Long-term outcomes show persistent resolution of clinical symptoms in 76% of patients who underwent revascularization in addition to decompression, compared with 53% of patients who received decompression alone 1

Important Considerations

• Not all patients with imaging evidence of celiac compression are symptomatic, as compression may be a normal finding in up to 20% of the population 1, 2
• Predictors of successful surgical outcomes include postprandial pain pattern (81% cure rate), age between 40-60 years (77% cure rate), and weight loss of 20 pounds or more (67% cure rate) 1, 2
• Endovascular stent placement alone without surgical release of the MAL is not recommended due to persistent extrinsic compression and risk of stent fracture 1, 2

Potential Complications

• MALS can cause pathological hemodynamic changes in the abdominal vasculature, including development of collateral circulation 3
• Approximately 48% of patients with MALS may develop visceral artery aneurysms, which can rupture and cause life-threatening bleeding 3
• Follow-up is advised for patients who develop collateral circulation to monitor for aneurysm formation 3

Non-Surgical Management

• Nonoperative approaches (counseling, analgesia, dietary modifications) have shown limited success, with only about 33% of patients reporting improvement compared to 93% with operative management 1
• Systemic anticoagulation has limited data to support its use in patients with MAL compression without evidence of thrombosis 1