May-Thurner Syndrome

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What is May-Thurner Syndrome?

May-Thurner Syndrome (MTS), or Iliac Vein Compression Syndrome, is caused 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 (DVT) in that leg. DVT occurs 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 Pulmonary Embolism (PE).

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. When the iliac artery compresses the iliac vein, it 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. 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 symptoms such as:

  • Leg ulcers
  • Pain
  • Swelling

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.

How is May-Thurner Syndrome Diagnosed?

May-Thurner Syndrome can be difficult to diagnose because of its 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 in order 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)
  • Affected area is warm to the touch
  • 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 perform an ultrasound from inside the blood vessel.

How is May-Thurner Syndrome Treated?

May-Thurner 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 have 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 MTS? At USA Vein Clinics, we offer effective, non-surgical treatment that is performed in our outpatient clinics. 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 treatment effectively treats MTS by leaving the vein open for efficient venous drainage from the left leg and helps reduce your risk of developing DVT, as well.

We encourage you to schedule an appointment online today to receive the diagnosis and treatment you need to have healthy veins.

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