What Causes May-Thurner Syndrome?

If you develop a deep vein thrombosis (DVT), especially if it’s in your left leg, you could’ve had a condition called May-Thurner syndrome for months or years and not known it. In many patients with DVT, May-Thurner syndrome is revealed after the fact, explaining why they were at risk for a blood clot.

At Memphis Vein Center in Memphis, Tennessee, Dr. Kishore K. Arcot can check for and diagnose May-Thurner syndrome and assess your risk for additional health problems like a DVT.  

What causes May-Thurner syndrome?

Your blood runs in a loop, carried away from your heart to your extremities by arteries to deliver oxygen, then returned to your heart through veins. The iliac arteries are located in the pelvis, and feed oxygenated blood to your legs. The corresponding iliac veins bring blood from the legs back to the heart.

The right iliac artery crosses over the left iliac vein. Sometimes, the artery can compress the vein at that point. This creates the same effect as stepping on a garden hose; it narrows the vein and slows the flow of blood, which may cause swelling in the left leg as well as other symptoms. This iliac compression is called May-Thurner syndrome. 

It can also happen (although more rarely) on the right side or both sides at once.    

Symptoms of May-Thurner syndrome

Most people have no symptoms, so they don’t realize they have this condition. 

However, when symptoms of May-Thurner syndrome are present, they may include:

• Leg swelling, especially on the left side
• Achiness in the lower extremities
• Pelvic heaviness or pain
• Varicose veins in the legs and pelvic area
• Leg pain during exercise, walking, or standing
• Thigh discomfort after sitting for long periods
• Shoes getting tighter as the day goes on 
• Skin discoloration or ulcers on the lower legs or feet

Risks associated with May-Thurner syndrome

May-Thurner syndrome is more common in women than in men. The primary concern for patients with the condition is the increased risk of deep vein thrombosis (DVT), which is a blood clot that forms in a leg vein. If the clot breaks off and travels through the bloodstream, it can reach the lungs and cause a pulmonary embolism. 

In a study of more than 1,000 people with DVT, May-Thurner syndrome was the underlying cause in 46% of patients.  

Treating May-Thurner syndrome

The treatment for May-Thurner syndrome typically involves one of three approaches:

• Angioplasty (opening the vein with a catheter and small inflatable balloon) followed by placing a stent (a mesh cylinder that holds the vein open)
• Bypass surgery to reroute blood into a healthier vein
• Repositioning of the artery to relieve pressure on the vein 

If you have symptoms associated with May-Thurner syndrome or DVT, it’s important to contact us as soon as possible. Dr. Arcot can evaluate your risks and recommend the best treatment for you. Contact us at 901-310-2771 or request an appointment online.