Pelvic Venous Compression or (May Thurner Syndrome)
This condition impacts women and less commonly men and occurs when there is a narrowing or obstruction of the veins that drain blood from the pelvis.
Commonly the iliac vein is involved, which may be compressed or squashed between the artery that supplies the right leg and the spine.
“It is usually the left vein of the leg that is affected although other veins nearby can also be affected and there is an irritation of that vein by the artery, causing webs of scarring to develop inside of the vein,” says Dr Huber.
Symptoms can include:
- Swelling of one leg or both, (usually left)
- A dull aching or dragging pain in the pelvis or lower back, particularly on standing and worse around menstruation.
- Pain during intercourse
- Irritable bladder is another symptom, which can rarely lead to stress incontinence
- Back pain
- Varicose veins, pigmentation around the ankle, eczema, itching or ulcers around the ankle.
“This syndrome is surprisingly common and occurs in 20-25% of people although many live their whole lives with no symptoms,” says Dr Huber.
He says Pelvic Venous Compression does carry an elevated risk of DVT, which can be diagnosed by venous ultrasound.
Pelvic Congestion Syndrome
Pelvic congestion syndrome relates to a combination of symptoms and signs associated with high pressure in the venous system in the pelvis. Raised venous pressure in the pelvis is caused by one of 2 conditions.
1. Ovarian Vein Incompetence
is related to (usually the left) ovarian vein which should be draining blood out of the pelvis up to the main veins draining into the heart. The ovarian vein has valves which should allow flow only in one direction and that direction is from the pelvis up towards the chest. In some women, these are not working, and the direction of flow in the ovarian vein is from the upper abdomen down into the pelvis causing congestion in the veins of the pelvis.
2. Iliac Vein Compression (May Thurner)
The 2nd cause of pelvic congestion syndrome is where the veins draining the legs become compressed or squashed in the pelvis. These are the iliac veins, and it is usually the left side which can be squashed between an artery and the spine. This makes it difficult for blood to drain from the leg through the pelvis back to the upper abdomen and heart. The pressure in the venous system in the pelvis rises resulting in pelvic venous congestion. This condition is called iliac vein compression or pelvic venous compression. Sometimes it is called May Thurner syndrome. Compression is relatively common. It is seen in between 20 and 25% of people and is more common in women than in men. Most people do not have any problems related to it, but the percentage that does have problems is not known. It has been recognised for many years (first described by May and Thurner in 1957) but the diagnosis has been difficult to make. More recently, there are ultrasound protocols designed to make the diagnosis. Other diagnostic tools include venogram, magnetic resonance venography and intravascular ultrasound.
There are many conditions which can give rise to pelvic aching and discomfort, one of which is pelvic congestion syndrome. This condition is more common in women. Symptoms include chronic swelling of the left leg (sometimes both); varicose veins especially if they return after adequate initial treatment; chronic venous insufficiency including pigmentation around the ankle, eczema itching or ulcers.
Download our brochure on Pelvic Venous Compression here.