What is the recommended treatment for a patient with May-Thurner syndrome?

Treatment of May-Thurner Syndrome

Endovascular stent placement following catheter-directed thrombolysis is the recommended treatment approach for May-Thurner Syndrome, with studies showing 90-96% patency rates at 1-year follow-up and complete symptomatic regression in approximately 82.6% of patients. 1

Diagnosis and Presentation

May-Thurner Syndrome (MTS) is characterized by compression of the left common iliac vein between the right common iliac artery and the pelvis/lumbar vertebrae, leading to:

• Lower extremity edema (especially left-sided)
• Back or abdominal pain
• Leg heaviness, pain, and cramping
• Dilated superficial collateral venous circulation
• Development of varicose veins
• Deep vein thrombosis (DVT) in many cases 1

Diagnostic Approach:

1. Ultrasound duplex Doppler of lower extremities as first-line imaging for suspected DVT 1
2. Advanced imaging with CT Venography or MR Venography to assess compression extent and identify associated thrombosis 1
3. Vessel diameter measurement by ultrasound to evaluate compression severity 1

Treatment Algorithm

1. For MTS without thrombosis:

• Compression therapy with graduated compression stockings
• Elevation of affected limbs
• NSAIDs for symptom relief 1
• Consider prophylactic endovascular intervention in symptomatic patients

2. For MTS with acute thrombosis:

• First-line therapy: Catheter-directed thrombolysis (CDT) or pharmacomechanical catheter-directed thrombolysis (PCDT) followed by endovascular stent placement 1
• Indications for CDT/PCDT include:
  • Limb-threatening circulatory compromise
  • Rapid thrombus extension despite anticoagulation
  • Symptomatic deterioration despite anticoagulation 1

3. Anticoagulation therapy:

• Required for at least 3-6 months after thrombosis 1
• Preferred agents:
  • Low-molecular-weight heparin (LMWH) or direct oral anticoagulants (DOACs) over unfractionated heparin for initial management 1
  • While warfarin has traditionally been used, evidence suggests DOACs like rivaroxaban can be safely used after stenting 2

4. Mechanical thromboprophylaxis:

• Early use of intermittent pneumatic compression (IPC) devices while patient is immobile 1
• Combined pharmacological and IPC within 24 hours after bleeding risk is controlled 1

Stent Selection and Outcomes

• Self-expandable stents show excellent anatomic success rates of 83-98% for recanalization of occluded veins 1
• Patency rates remain high at 90% when stents are limited to the iliac vein 1
• Patency rates of 84% when stent extension below the inguinal ligament is required 1

Follow-up and Monitoring

• Regular follow-up with Doppler ultrasonography to monitor:
  • Resolution of compression
  • Stent patency
  • Recurrent thrombosis 1

Important Considerations

• Anticoagulation therapy alone is insufficient for MTS treatment, as it doesn't address the underlying mechanical compression 3, 4
• Endovascular treatment is preferred over anticoagulation alone to reduce the chances of chronic venous hypertension 5
• The 12-month stent patency rate ranges from 60% to 100% with appropriate treatment 6
• MTS can occur in young males without risk factors, not just females, so maintain a low threshold for investigation 5

Complications to Monitor

• Partial stent thrombosis may occur even while on anticoagulation, requiring repeat stenting 2
• Post-thrombotic syndrome can develop in untreated or inadequately treated cases 1
• IVC filter complications if used: insertion site thrombosis (10%), recurrent DVT (20%), post-thrombotic syndrome (40%) 1

The evidence strongly supports endovascular intervention as the primary treatment for May-Thurner Syndrome, especially when associated with thrombosis, as this addresses both the mechanical compression and thrombus burden for optimal outcomes.