Pelvic Venous Disorders
Pelvic venous disorders or pelvic venous congestion syndrome is most often caused by ovarian vein reflux. It is a cause of chronic pelvic pain in approximately 13-40% of women. Chronic pelvic pain is pain in the lower abdomen which has been present for more than 6 months. Pelvic congestion syndrome is therefore a painful condition often caused by dilatation of the ovarian and/or pelvic veins (rather like varicose veins in the legs, but in the pelvis). This causes the blood to pool, due to gravity, causing enlarged, bulging veins. This is what happens to the pelvic veins in pelvic venous disorder/pelvic venous congestion syndrome (PVD/PVCS). This pressure results in the pain and may also cause visible varicose veins around the vulva, vagina, inner thigh, sometimes the buttock and down the legs.
The cause of the dilated ovarian/pelvic veins in PVCS is poorly understood. PVD/PVCS most commonly occurs in young women , and usually in women who have had at least 2-3 children. During pregnancy, the ovarian vein can be compressed by the enlarging womb or enlarged because of the increased blood flow. This is thought to affect the valves in the vein causing them to stop working and allowing the blood to flow backwards, contributing to PVCS.
There are other causes that may cause obstruction to the ovarian and pelvic veins leading to PVCS, which are much less common, and are the result of vein obstruction. PVCS may also be associated with polycystic ovaries.
The absence of the vein valves due abnormal development may be a contributing factor.
The symptoms of PVCS are due to the dilatation of the pelvic veins and because the blood is flowing the wrong way (i.e. backwards). The varicose veins in the pelvis surround the ovary and can also push on the bladder and rectum. This can cause the following symptoms:
- Pelvic pain or aching around the pelvis and lower abdomen
- Dragging sensation or pain in the pelvis
- Feeling of fullness in the legs
- Worsening of stress incontinence
- Worsening in the symptoms associated with irritable bowel syndrome
Pain is usually commonest symptom and present for over 6 months duration. The pain is usually on one side but can affect both sides. The pain is worse on standing, lifting, when you are tired, during pregnancy and during or after sexual intercourse. The veins are also affected by the menstrual cycle/hormones and therefore the pain can increase during the time of menstruation. The pain usually is improved by lying down.
However, not every woman with pelvic vein reflux will get symptoms, and many only do following pregnancy. This is because after pregnancy, the veins can dilate more because of the compression from the womb. This then causes the varicose veins in the vagina/vulva to form (Diagram 3). The varicose veins can decrease after pregnancy, but may deteriorate over time.
The first way to diagnose PVCS is by typical symptoms and if visible varicose veins are found on examination. Many women have a history of varicose veins around their vulva during their pregnancy. On examination, you can see these veins around the vulva, and they may extend down the inner thigh. On the inner thigh, there is a muscle tendon along which the dilated veins are felt and seen. If the veins lie behind this tendon and or run behind the leg it is most likely they are dilated caused by reflux from the ovarian and/or pelvic veins.
Ultrasound examination may be useful (US). This imaging test uses sound waves to detect the abnormal veins. It is good at showing the blood flow through the veins and is non-invasive. However, sometimes the veins in the pelvis are difficult to see through the abdomen, therefore a special ultrasound where a small probe is placed into the vagina to see the veins, called a transvaginal ultrasound may be required.
The diagnosis may still require further investigation through non-invasive imaging with magnetic resonance imaging (MRI) and computed tomography (CT). This allows us to see where the varicose veins are coming from so that we can plan and do the appropriate treatment. Usually it is the ovarian veins that cause the varicose veins, but other pelvic veins can also be responsible.
IR Diagnosis and Treatment
Although US, CT and MRI may be initially used, pelvic venography is still used to diagnose PVCS and assess the anatomy before treatment is considered. This can be done at the same time as ovarian vein/pelvic vein treatment (embolization) or as a separate procedure if the treatment options need further consideration. This is a more invasive test, but is a simple and safe diagnostic procedure. It is done by injecting dye (contrast) that can be seen on the x-ray machine (fluoroscopic machine) through a small tube (catheter) placed in the vein at the groin (the common femoral vein) or neck (internal jugular vein) under local anesthetic. A catheter is placed in the ovarian and pelvic veins, contrast is then injected and the images seen on the fluoroscopic machine give a picture of the anatomy. It allows your doctor to see the abnormal veins. After the images have been taken, the tube is removed, and a little pressure is placed over the small cut in the groin or neck to stop any bleeding. You can then go home 1-4 hours later.