May-Thurner syndrome (MTS) is a type of vein disease that can have a significant impact on the health of the veins but is difficult to diagnose. In the pelvic region of the body, the right iliac artery naturally crosses the left iliac vein. The close proximity of these blood vessels, in people with May-Thurner syndrome, can lead to the artery placing pressure on the vein. The pressure causes the vein to become pinched between the artery and vertebrae in the back. The exact cause of why this increased compression happens is unclear.
The added pressure restricts blood from flowing as freely through the left iliac vein. The pressure can cause scarring in the vein. If the pressure is severe enough, it can also restrict the blood flow and lead to blood pooling (stasis), allowing blood clots to form. Blood clots can increase a person’s risk of developing deep vein thrombosis (DVT), a type of clot that can potentially become life-threatening if left untreated.
MTS frequently causes pain when the legs are “dependent” (hanging down while sitting); in addition, there may be significant swelling in the whole leg. The Vein Clinic at Novus Spine & Pain Center in Lakeland, Florida, specializes in diagnosing and treating May-Thurner syndrome, which can occur in both adults and children. It is most common in women between the ages of 20 and 40, especially after pregnancy or following an extended period of inactivity.
Symptoms of May-Thurner Syndrome
Many people with MTS have no symptoms, even if there is a pronounced narrowing of the iliac vein. In many cases, MTS is diagnosed after the discovery of a DVT. In some cases, people with severe vein narrowing experience leg swelling and pain that is often described as chronic venous insufficiency. Unfortunately, there usually aren’t warning signs of MTS. Any pain that develops is often noticeable when the affected leg hangs down from the edge of a bed or chair, which can include significant swelling of the whole limb.
Physicians have expanded the definition of May-Thurner syndrome to a broader disease profile called nonthrombotic iliac vein lesions (NIVL). This condition can involve both the right and left iliac veins as well as multiple other blood vessels. MTS is also known as iliac vein compression syndrome, iliocaval compression syndrome, and Cockett syndrome.
Treatment of May-Thurner Syndrome
The treatment of May-Thurner Syndrome depends upon the presence of symptoms and their severity, and whether a DVT is present. Common treatments are implemented to resolve the symptoms and risks associated with MTS, especially those related to a DVT. In less serious cases, MTS can be managed by wearing compression stockings that improve blood flow through the legs while helping to prevent swelling and pain.
Options for treating a DVT include administering anticoagulants (blood thinners). The goal is to treat existing clots and to stop new clots from forming. To accomplish this, doctors have several options, including:
- Blood thinners. Drugs commonly used to treat DVTs. The drug helps prevent new clots and keeps existing ones from growing larger. These medicines are called anticoagulants.
- Clot busters (Thrombolysis). For more serious clots, medicine is delivered through an intravenous (IV) line or through a long catheter directly to the site of the blockage. The drug typically breaks down the clot in a few hours to a few days.
- Angioplasty and a stent. The doctor uses a small balloon to expand the left iliac vein (angioplasty), then inserts a stent. The stent is a tiny cylinder, made of metal mesh, which keeps the vein open so blood can flow normally.
- Vena cava filter. If blood thinners are not a good option for a patient, the doctor may place a filter in the vena cava (a large vein in the belly). Although the filter doesn’t prevent clots from forming, it catches the clot before it reaches the heart and lungs.
- Bypass surgery. The doctor builds a new path for the blood to flow. It is like a detour around the part of the left iliac vein that’s being squeezed.
- Surgery to move the right iliac artery. An operation to shift the position of the artery, so it sits behind the left iliac vein.
- Tissue sling. With this surgery, a piece of tissue is placed as a cushion between the two blood vessels.
Some of these surgeries for treating May-Thurner syndrome are done on an outpatient basis, allowing the patient to go home the same day after the procedure. Depending on the procedure, the patient may be able to return to normal activities within a few days to a week. The doctor may also recommend lifestyle changes the patient can make to reduce the risk of developing new clots.
Novus Spine & Pain Center
The Novus Spine & Pain Center is in Lakeland, Florida, and specializes in treating chronic pain. By using a comprehensive approach and cutting-edge therapies, we work together with patients to restore function and regain an active lifestyle, while minimizing the need for opiates.
Our Mission Statement: To provide the best quality of life to people suffering from pain, by providing state of the art treatments, knowledge and skill, compassion, and respect for all.
May-Thurner Syndrome Resources
What is May-Thurner Syndrome? (WebMD)
4 Important Things You Need to Know About May-Thurner Syndrome (Vein Directory.org)
May-Thurner Syndrome (Cleveland Clinic)
May–Thurner Syndrome (Wikipedia)
May-Thurner Syndrome (Healthline)
May-Thurner Syndrome (National Blood Clot Alliance/StopTheClot.org)
May-Thurner Syndrome (ClotConnect.org)
May-Thurner syndrome: a not so uncommon cause of a common condition (PubMed)
May-Thurner Syndrome (Vascular Disease Management)
May-Thurner Syndrome (UpToDate)