Treatment of May-Thurner Syndrome

Understanding May-Thurner Syndrome

May-Thurner syndrome (MTS) is an anatomical variant characterized by compression of the left common iliac vein by the overlying right common iliac artery against the lumbar vertebrae, leading to venous stenosis, which predisposes patients to deep vein thrombosis (DVT), particularly in the left lower extremity 1

Duplex ultrasound is the first-line imaging examination for suspected DVT, though it may not visualize the common iliac vein compression 2
CT venography or MR venography should be performed when MTS is suspected to visualize the iliac vein compression 1, 2
Diagnosis should be considered in patients with left-sided iliofemoral DVT, especially when unprovoked or recurrent 3, 1

Catheter-directed thrombolysis (CDT) or pharmacomechanical catheter-directed thrombolysis (PCDT) is recommended for patients with iliofemoral DVT associated with limb-threatening circulatory compromise (phlegmasia cerulea dolens) 3
Endovascular intervention with stent placement is the preferred treatment for MTS to address the mechanical compression 3, 1
Angioplasty and stenting of the compressed iliac vein is a treatment option for MTS 3, 1

Surgical venous thrombectomy by experienced surgeons may be considered in patients with iliofemoral DVT who have contraindications to or failure of catheter-directed therapies 3

Endovascular treatment with stenting has shown good outcomes in maintaining venous patency 3, 1
Studies have demonstrated that stent placement following thrombus removal significantly reduces the rate of early rethrombosis compared to thrombus removal alone 3
Proper treatment reduces the risk of post-thrombotic syndrome and improves quality of life 3, 1

Patients with untreated or chronic May-Thurner syndrome can develop post-thrombotic syndrome, characterized by chronic pain, swelling, and skin changes following deep vein thrombosis, as reported by the Journal of Thrombosis and Haemostasis 4

The American Society of Hematology recommends starting low molecular weight heparin (LMWH) or unfractionated heparin immediately upon diagnosis, with LMWH being superior to unfractionated heparin for initial DVT treatment, particularly for reducing mortality and major bleeding risk 5, 6
The American College of Physicians suggests transitioning to long-term oral anticoagulation with warfarin (target INR 2.0-3.0) overlapped with initial anticoagulant for minimum 5 days and until INR >2.0 for at least 24 hours, or consider direct oral anticoagulants (DOACs) as an alternative 6

The American Society of Hematology guidelines recommend a minimum of 3 months of anticoagulation for all patients with DVT, with extended-duration therapy beyond 12 months considered for unprovoked DVT, which decreases the relative risk for recurrence by 64% to 95% 5, 6

The American College of Physicians recommends initiating compression stockings within 1 month of diagnosis of proximal DVT and continuing for a minimum of 1 year, which markedly reduces the incidence and severity of post-thrombotic syndrome 6

The American College of Obstetricians and Gynecologists suggests that LMWH is the anticoagulant of choice in pregnant or postpartum women, as warfarin crosses the placenta and causes embryopathy between 6-12 weeks' gestation 6