May-Thurner Syndrome (MTS) | Tests & Treatments | MedStar Health

Compression of the large vein in the left leg

A doctor examines the leg of a male patient in a clinical setting.May-Thurner syndrome (MTS) occurs when the vein that runs from the left leg to the large vein in the abdomen (left common iliac vein) becomes pinched between the artery that runs to the right leg (right common iliac artery) and the spine. MTS can increase your risk of deep vein thrombosis, chronic venous insufficiency, and blood clots. Other names for May-Thurner Syndrome include Iliac vein compression syndrome, iliocaval venous compression syndrome and Cockett’s syndrome.

May-Thurner Syndrome is found to occur twice as often in women than men. It is also more commonly diagnosed in adults between 20-50 years of age.

The vascular surgeons in our Vascular and Endovascular Program offer the latest minimally invasive procedures and techniques to address and prevent vascular complications from these conditions.

May-Thurner syndrome may not cause symptoms, but you should see your doctor if you experience:

  • Edema, or swelling, in your leg

  • Enlarged leg veins
  • Leg pain, tenderness, throbbing or discoloration
  • Leg or foot ulcers

  • Heaviness in the leg


Diagnosing May-Thurner syndrome is the first step to developing a treatment plan. Our specialists may recommend one or more diagnostic and imaging procedures.

Angiogram (Angiography)

An angiogram is a special X-ray taken as a special dye is injected through a thin, flexible tube called a catheter to detect blockages or aneurysms in blood vessels.

Cardiac Catheterization

Cardiac catheterization is a minimally invasive way to diagnose and treat a variety of heart and vascular conditions by guiding thin, flexible tubes called catheters through blood vessels to problem areas.

Carotid Duplex Ultrasound

Carotid duplex ultrasound uses Doppler and traditional ultrasound to assess blood flow in the arteries that supply blood to your brain.

Computerized Tomography (CT) Scan

The cardiac computed tomography scan, or cardiac CT, uses X-rays to create three-dimensional images of your heart and blood vessels.


An echocardiogram uses high-frequency sound waves to create images of your heart.

Electrocardiogram (ECG)

An electrocardiogram, also known as an ECG, measures the heart’s electrical activity.


A fluoroscopy is an imaging technique that uses a continuous X-ray beam passed through the body to create real-time, moving images of your internal structures.

Fractional Flow Reserve

Fractional flow reserve, also known as FFR, is a measurement of how well blood can flow through the coronary arteries. Narrowing or blockages in these arteries can lead to a heart attack without treatment.

Magnetic Resonance Imaging (MRI)

Magnetic resonance imaging, better known as cardiac MRI, is a combination of radio waves, magnets, and computer technology used to create images of your heart and blood vessels.

Pulse Volume Recording

Pulse volume recording tests are used to evaluate blood flow through the arteries in your arms or legs.

Stress Tests

Stress tests are used to assess how your heart works during physical activity. There are several types of stress tests, including treadmill or bike stress tests, nuclear stress tests, stress echocardiograms, and chemically induced stress tests.


A contrast dye is inserted into the blood vessel and x-rays are used to measure blood flow through the veins, particularly in the legs and pelvis.


Treatment focuses on improving the venous blood flow and reducing the risk of a deep vein thrombosis (DVT).

Bypass Surgery

A small bypass graft is used to help reroute the blood around the compressed part of the vein.

Inferior Vena Cava (IVC) Filters

An IVC filter is a small, wiry device that is placed within the inferior vena cava (a large vein) to prevent blood clots from traveling to the lungs.


Stenting uses a mesh tube to open narrow blood vessels and improve blood flow.

Right Iliac Artery Repositioning

Surgically moving the right iliac are artery behind the left iliac vein to reduce the compression; in some cases, tissue may be placed between the artery and vein to relieve pressure.


Thrombolysis, also known as thrombolytic therapy, is a treatment to dissolve or break up dangerous blood clots that can cause heart attacks, strokes, and other conditions.

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