Peripheral Vascular Partners

May-Thurner Syndrome

What is May-Thurner Syndrome?

May-Thurner syndrome, or MTS, is a condition that involves the compression of the left iliac vein by the right iliac artery deep inside the pelvis limiting venous outflow from the left leg. Because of the position of this vein and artery, MTS usually only occurs in the patient’s left leg but can rarely occur on the right. MTS increases the chance of developing deep vein thrombosis in the leg. Deep vein thrombosis is the partial or complete blockage of blood flow through a deep vein, usually in the legs, manifesting in the form of a blood clot. 


MTS is most prevalent among women between the ages of 20 to 45. Women who have recently had a child, or have had more than one child also have a higher risk. Scoliosis and the use of oral birth control can also contribute to a patient’s chance of suffering from May-Thurner syndrome.

What are the symptoms associated with May-Thurner Syndrome?

The main issue with May-Thurner syndrome is that there are often no symptoms at all. There is the possibility a patient will experience some pain or swelling in their left leg, but often MTS presents as symptomless. 


While often presenting with no symptoms, untreated MTS may lead to a deep vein thrombosis. Deep vein thrombosis symptoms include significant swelling in the leg, pain or cramps, discoloration of the skin, and swollen veins sensitive to the touch. If left untreated, deep vein thrombosis can lead to serious complications if the blood clot breaks free and travels into the bloodstream through the heart into the lungs. If the clot becomes lodged in the lungs, it can cause a life-threatening condition known as pulmonary embolism.


This is why it’s best to find MTS early, and seek treatment before it becomes a symptomatic deep vein thrombosis. Diagnosis is done with a physical exam, and an assessment of your medical history. An interventional radiologist will use a venogram with ultrasound inside the vein to look at the condition of your veins, and see if a blood clot is beginning to form. Once they have identified the signs of MTS, you can begin to seek treatment which can include a stent to open the vein.

How is May Thurner Syndrome treated?

A venogram is imaging of a vein obtained with a small amount of contrast dye and/or carbon dioxide. This imaging can be both diagnostic and/or for treatment. This is done by making a small nick in the skin at the access site, usually the groin. A thin catheter is then placed into the vein for imaging and potential treatment. This imaging allows our Vascular Interventional Radiologists to see if there is compression of the Iliac vein by the Iliac artery. If there is significant compression, a stent will then be permanently placed into the vein. A balloon, called a venoplasty, is then placed into the vein temporarily inflated to enlarge the vein and ensure proper stent placement. This can help with diagnosing and treating May-Thurner.