May-Thurner Syndrome

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May-Thurner Syndrome: Symptoms, Causes, and Treatment

Have you been diagnosed with Deep Vein Thrombosis (DVT) in your left leg? Or, have you noticed any unusual swelling in this region of your body? Although you may have never heard of it, May-Thurner Syndrome (MTS) can potentially cause these dangerous symptoms. MTS, though rare, often remains undiagnosed and can lead to serious health consequences.

Below, you will discover everything you need to know about May-Thurner Syndrome, what causes it, and how it is diagnosed. The good news is that you are in expert hands with our vein specialists at USA Vein Clinics. We are available to fill you in on May-Thurner Syndrome treatment and help manage your overall vein health.

What Is May-Thurner Syndrome?

May-Thurner Syndrome (MTS), or Iliac Vein Compression Syndrome, occurs when the right iliac artery compresses the left iliac vein. This causes the left leg to swell and increases the risk of Deep Vein Thrombosis in that leg. DVT develops when a blood clot blocks the flow of blood through a vein.

Most people are not aware they even have MTS until they are diagnosed with DVT. DVT is a serious condition because if the blood clot breaks free, it can lead to a Pulmonary Embolism (PE). A Pulmonary Embolism involves the blockage of one of the pulmonary arteries in the lungs. Because of this blockage, PE is considered a potentially life-threatening condition and requires immediate medical attention.

Keep an eye out for DVT symptoms like pain, swelling, redness, warmth, and tenderness. If you notice any, head directly to your nearest emergency room.

What Causes May-Thurner Syndrome?

The iliac artery is located near the pelvis and carries nutrient-rich blood from the heart to the back and other areas of the body. The iliac vein is located in the abdomen. Its role is to drain blood from the pelvis and lower limbs. May-Thurner Syndrome causes the iliac artery to compress the iliac vein. This restricts the blood flow out of the left leg, causing swelling. While MTS may not cause immediate harm, it can lead to the development of more serious conditions, including DVT.

Doctors aren’t sure how many people have May-Thurner Syndrome, as it often produces no symptoms. However, a 2016 study suggested MTS may affect up to 10% of the population. Perhaps more importantly, other research suggests the syndrome may increase your risk of developing DVT. It is responsible for 2-3% of DVT cases that occur in the lower limbs.

May-Thurner Syndrome Risk Factors

May-Thurner Syndrome most commonly occurs in women ages 20 to 40. The chance of developing MTS is higher after pregnancy or long periods of inactivity. Due to the reduction in blood flow as a result of the narrowing of the left iliac vein, you may have May-Thurner Syndrome symptoms such as:

  • Venous leg ulcers
  • Pain
  • Swelling
  • Other sensations like itching or burning

Unfortunately, MTS does not usually have any warning signs or symptoms. Regardless of whether you have MTS, other risk factors that increase your risk of DVT include the following:

  • A recent surgery or accident: Trauma, surgery or infection can damage veins, leading to blood clots.
  • A blood-clotting disorder: If you have a blood clotting disorder or a family history of blood clots, this can increase your risk of DVT.
  • Extended stretches of inactivity: This includes driving or flying for long periods of time.
  • Smoking: Smoking can affect circulation and blood clotting, increasing your risk of DVT.
  • Varicose veins: Having varicose veins increases your risk of DVT.
  • Cancer: Some forms of cancer can increase your risk of blood clots, as can chemotherapy.
  • Obesity: Being overweight or obese can increase the pressure in your veins, upping your risk of DVT.
  • Pregnancy: The expanding uterus and pregnancy-related weight gain can increase the pressure on the veins in your legs.
  • Age: The older you are, the more likely you are to have DVT.

These same risk factors can also lead to the development of vein disease, or venous insufficiency. Vein disease is the underlying cause of varicose and spider veins. It occurs when vein valves become damaged and struggle to pump blood back to the heart. This leads to blood pooling, most commonly in the legs, ankles, and feet.

Common vein disease symptoms include:

  • Swelling in your legs and ankles
  • Cramping or aching in the thigh or calf
  • Tired or heavy legs
  • Restlessness, especially at night
  • Itchy, dry, or hardened skin on your legs
  • Wounds on your legs or ankles that take a long time to heal or don’t heal at all
  • Leg pain that is alleviated when you walk or elevate your legs

If you are concerned about your vein health, we recommend contacting your doctor as soon as possible. When vein disease is left untreated, it can put you at increased risk for serious health conditions like blood clots and venous ulcers. Our vein specialists can advise you on available, minimally invasive vein disease treatments.

How Is May-Thurner Syndrome Diagnosed?

In many cases, establishing a May-Thurner Syndrome diagnosis can be challenging due to a lack of symptoms. The most common sign that you have MTS is the development of DVT. Your doctor will conduct a physical examination and ask about your medical history to make an MTS diagnosis.

While you may have no iliac vein blockage symptoms, the common symptoms of DVT include:

  • Swelling in the leg (or less frequently, the arm)
  • Warmth when you touch the affected area
  • Skin redness on the legs
  • Pain or tenderness in your lower body, such as a cramp

If you are experiencing shortness of breath, chest pain, or a blood-producing cough, seek immediate help. These symptoms could indicate a pulmonary embolism (PE), a blood clot that travels from a leg to the lungs.

In addition to your medical history and a physical exam, your doctor may also order imaging tests to determine whether your left iliac vein is narrower than normal. Those tests may include:

  • A CT scan, which uses X-rays and a computer to produce images of blood clots inside the body
  • An MRI scan, which uses magnetic fields and radio waves to generate images of organs and soft tissues inside the body
  • Ultrasound, which uses high-frequency sound waves to see your body’s internal structures.
  • Venogram, which takes an X-ray of your vein using special dye

Other options include a catheter-based venogram or an intravascular ultrasound, which allows your doctor to perform an ultrasound from inside the blood vessel.

How Is May-Thurner Syndrome Treated?

May-Thurner Syndrome treatment may depend on your symptoms and how severe they are. If you have symptoms of MTS, treatment typically is aimed at improving the blood flow in your left iliac vein. This can ease your symptoms and may also help lower your risk of developing DVT.

Some of the possible treatments for MTS include:

  • Angioplasty and stenting: To perform angioplasty, your doctor inserts a catheter with a balloon in its tip into your vein and inflates the balloon to open the vein. A tiny mesh tube, called a stent, is inserted into the vein to keep it open, and the balloon is then removed.
  • Bypass surgery: With bypass surgery, a bypass graft reroutes blood around the compressed part of a vein.
  • Repositioning: Your doctor moves the right iliac artery behind the left iliac vein to remove the pressure on the vein.

If you develop DVT due to MTS, your doctor may treat it with blood thinners, clot-busting medications, or other treatments.

Living With May-Thurner Syndrome

It’s quite possible to have May-Thurner Syndrome without ever knowing you have it, as it often produces no symptoms. If you do have symptoms of DVT, however, it’s important to see a doctor to seek treatment.

May-Thurner Syndrome Treatment at USA Vein Clinics

Ready to seek treatment for May-Thurner Syndrome? At USA Vein Clinics, we offer effective, non-surgical treatment that is performed in our outpatient clinics.

During MTS treatment, we inflate the iliac vein to widen it and increase blood flow. After the vein is widened, a permanent stent is placed in the vein to keep it open. This technique leaves the vein open for efficient venous drainage from the left leg and helps reduce your risk of developing DVT.

We encourage you to schedule an appointment online today to receive the diagnosis and treatment you need to have healthy veins. You can visit us at one of 90 clinic locations or online with our convenient telemedicine options.

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