Leg pain and swelling can be caused by a number of problems, many of them venous in nature. One serious condition with these symptoms is May-Thurner syndrome.

Caused by the compression of an important vein against the spine, May-Thurner syndrome is the narrowing of the vein that runs from the left leg to the vena cava. It typically presents with a left lower extremity that I slightly larger than the right.

The right iliac artery runs to the right leg. This artery can compress the left iliac vein against the spine, causing narrowing and scarring. In healthy patients, the right iliac artery simply runs over the left iliac vein, without applying pressure.

Patients with May-Thurner syndrome will experience left leg swelling and pain, and in more severe cases may experience blood clots or deep vein thrombosis in the left leg.

How Do I Know If It’s May-Thurner Syndrome?

As before mentioned, left leg swelling and pain can be symptoms of various venous issues, like venous reflux or varicose veins. Various tests can detect May-Thurner syndrome, such as ultrasound imaging, MRI, CT scans, venogram or phlebogram.

Treatment Options

The narrowed vein in patients with May-Thurner syndrome can be treated in various ways. Stenting can hold the vein open. Bypass surgery, another option, rerouts blood flow around the narrowed, scarred portion of the left iliac vein.

In some cases, the best option is to surgically reposition the right iliac artery, the artery that causes the pressure. Surgery can move the artery behind the left iliac vein.

In other cases, what a patient needs is removal of blood clots in the vein, in the pelvic region. Using medication and a specialized device, physicians can remove these clots.

How Common is It?

May-Thurner syndrome is relatively rare, though it often goes unrecognized, research shows. It is much more common in women than men.