From the Guidelines
May-Thurner syndrome is a vascular condition where the left iliac vein is compressed by the right iliac artery against the spine, increasing the risk of deep vein thrombosis (DVT) in the left leg. This anatomical compression restricts blood flow from the left leg, causing blood to pool and potentially form clots. Symptoms may include leg swelling, pain, skin discoloration, and varicose veins, though many people remain asymptomatic until a DVT develops.
Key Points
- Diagnosis typically involves imaging studies like ultrasound, CT venography, or MRI 1.
- Treatment depends on severity and may include blood thinners (anticoagulants) such as warfarin, rivaroxaban, or apixaban for 3-6 months if a clot is present.
- For more severe cases, interventional procedures like angioplasty, stent placement, or thrombolysis may be necessary to restore proper blood flow, particularly in cases with underlying anatomic compression syndrome, such as May-Thurner syndrome, where stent placement has been shown to be beneficial in addition to anticoagulation 1.
- The condition is more common in women, particularly those who are pregnant or taking hormonal contraceptives, as these factors further increase clotting risk.
- Anyone with unexplained left leg swelling, especially with risk factors, should seek medical evaluation promptly.
Treatment Considerations
- Anticoagulation alone remains the pillar of care for iliofemoral venous thrombosis, but in cases of May-Thurner syndrome, additional measures such as stent placement may be necessary to address the underlying anatomic compression 1.
- The use of percutaneous transluminal venous angioplasty and stent placement has been used to treat obstructive lesions and prevent rethrombosis in patients with acute iliofemoral deep vein thrombosis (IFDVT) and May-Thurner syndrome 1.
From the Research
Definition and Characteristics of May-Thurner Syndrome
- May-Thurner syndrome (MTS) is a rare cause of deep venous thrombosis (DVT), characterized by the external compression of the left common iliac vein by the right common iliac artery against bony structures 2.
- This compression can lead to stenosis in the left common iliac vein, predisposing patients to DVT 3.
- MTS is also known by other names, including Cockett syndrome, iliocaval compression syndrome, and iliac vein compression syndrome 4.
Risk Factors and Clinical Presentation
- Risk factors for MTS include female sex (postpartum, multiparous, and using oral contraceptive pills), spinal abnormalities like scoliosis, prior aortoiliac vascular stent placement, dehydration, and hypercoagulability 2.
- Patients with MTS may present with unilateral leg swelling, pain, and swelling of the affected leg 5, 6.
- MTS can be asymptomatic in patients with partial obstruction, but progression to extensive symptomatic DVT and/or chronic venous insufficiency can occur 2.
Diagnosis and Treatment
- MTS can be diagnosed by non-invasive imaging studies, including ultrasound (US), computed tomography (CT) scan, magnetic resonance imaging (MRI), venogram, catheter-based venogram, and intravascular US 2.
- Treatment for MTS typically involves thrombectomy, angioplasty, and stenting of the affected segment, followed by anticoagulation therapy 2, 5, 3, 4.
- Anticoagulation therapy may include warfarin or novel oral anticoagulants like rivaroxaban 3.