What is May-Thurner Syndrome?

Kush Desai, MD

May-Thurner Syndrome is the most common form of iliac vein compression syndrome; when the left common iliac vein is compressed between the right common iliac artery and a part of the spine.  This can cause a lack of blood flow coming from the left leg, which can cause swelling and pain in the leg. When the left leg is swollen and is much larger than the right, doctors often suspect May-Thurner Syndrome.  This can also increase the risk of a clot forming in the deep veins of the left leg, or a deep vein thrombosis (DVT); which occurs when stationary blood begins to clot. 

When these symptoms occur, diagnosis depends on whether there is a DVT. Usually, an ultrasound of the left leg is done to evaluate whether clot is there and if there is anything wrong with blood flow in the leg. A CT scan or MRI of the pelvis may also be done. 

Treatment can vary and depends on severity of symptoms, whether DVT clot is there at the time of diagnosis, and overall health. In some cases compression stockings will be used to treat symptoms. In patients that have more significant symptoms, treatment such as a thrombectomy procedure (removing the blood clot from the leg) may be recommended; this is because DVT that is left untreated can lead to permanent damage to the veins in the leg, and can cause severe leg swelling, varicose veins, and occasionally open wounds known as ulcers.

Recently, devices have been created specifically to treat DVT, improving the efficiency and safety of thrombectomy procedures. These devices use a catheter (a small hollow tube) put inside the vein to help break up and remove the blood clot during the procedure. This treatment may be followed by the placement of a stent to keep the compressed iliac vein open, improving leg swelling and pain symptoms, and significantly reducing the future risk of DVT.