Uterine artery embolization

In uterine artery embolization — also referred to as uterine fibroid embolization — a doctor uses a slender, flexible tube (catheter) to inject small particles into the uterine arteries, which supply blood to your fibroids and uterus. The goal is to block tiny vessels that lead to your fibroids, starve the fibroids and cause them to die.

Uterine artery embolization takes advantage of the physiological changes caused by fibroids. A fibroid uterus has more small blood vessels than does a normal uterus because fibroids stimulate formation of new blood vessels to the tumors. During uterine artery embolization, small particles (embolic agents) follow this increased blood flow to the fibroids and lodge in branches that feed them. Doctors believe that most normal uterine tissue isn't harmed, in part because it gets blood from additional arteries (collateral circulation).

Interventional radiologists — medical specialists who use imaging techniques to insert tiny instruments through small incisions in the skin to diagnose and treat disease — usually perform uterine artery embolization. Some specialists in obstetrics and gynecology also know this technique.

Some studies have shown that uterine artery embolization reduces bleeding, urinary incontinence and abdominal enlargement in about 85 percent to 95 percent of women who undergo the procedure to treat their fibroids. However, many of these studies focused on small groups of women or covered periods of two years or less.

Five years after treatment with uterine artery embolization, more than 70 percent of women maintain symptom control. This percentage equals that of myomectomy, in which the fibroids are surgically removed and the uterus repaired.

What to expect

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	Catheterization
	Using emboli to stop blood flow

A doctor performs uterine artery embolization in a hospital under sterile conditions.

How do you prepare?
On the evening before the procedure, don't eat or drink after midnight. In the radiology procedure room, a staff member places a needle attached to a slender tube into a vein in your arm (intravenous, or IV) to give you fluids, anesthetics, antibiotics and pain medications. A thin tube placed in your urethra (urinary catheter) keeps your urinary bladder empty.

This procedure usually requires sedation, a type of anesthesia that reduces pain, yet allows you to breathe on your own, respond to questions and report any discomfort. It also blocks your memory of the procedure. Alternatively, you might undergo regional anesthesia. In this approach, the doctor injects medication around the spinal nerves that supply your pelvis. This method blocks pain, yet leaves you conscious and able to communicate.

How is it done?
To see your uterus and blood vessels, the radiologist uses a fluoroscope. The device is a pulsed X-ray beam that produces moving images of internal structures and displays them on a computer monitor. The radiologist makes an incision less than 1/4-inch wide (0.635 centimeter) in the skin over your groin, inserts a catheter into your femoral artery and guides it to one of your two uterine arteries. He or she injects a contrast fluid, usually containing iodine, which flows into the artery and its branches and makes them visible on the monitor.

Fibroids "light up" brightly because of their increased blood flow. The radiologist identifies and maps the vessels leading to the fibroids, then injects tiny particles made of plastic or gelatin into those branches. The radiologist injects more contrast and checks images to make sure that blood is no longer flowing to the fibroids. He or she then places the catheter into the other uterine artery and repeats the steps.

After the procedure
In the recovery room, staff members monitor your condition and administer IV medication to control nausea and pain. When the effects of the anesthesia fade, staff members bring you to your hospital room for continued observation.

You must lie flat for several hours to prevent pooling and clotting of the blood (hematoma) at the femoral artery site. Pain is the primary side effect of uterine artery embolization. Doctors believe it's a reaction to stopping blood flow to the fibroids. Some pain may also result from a temporary drop in blood flow to normal uterine tissue.

Pain usually peaks during the first 24 hours. You receive an IV opioid (morphine and related drugs), nonsteroidal anti-inflammatory drugs (NSAIDs) or both. Many hospitals offer patient-controlled analgesia (PCA), a system that delivers a dose of pain medication to your bloodstream through a vein when you press a button.

Post-embolization syndrome — fever, extreme fatigue, nausea and vomiting — is common after uterine artery embolization. Doctors believe that chemicals released by degenerating fibroids stimulate inflammation, causing the syndrome. Although post-embolization syndrome usually resolves spontaneously, it's important to rule out endometritis, a serious complication marked by delayed pain, a rise in the white blood cell count and a pus-like (purulent) vaginal discharge. Doctors treat endometritis with IV antibiotics.

By the next day, oral pain medications usually can replace IV medications. Your urinary catheter is removed, and you're encouraged to walk around. Recovery is generally rapid, and complications are rare.

Major complications

Major complications occur in about 1 percent to 5 percent of women undergoing uterine artery embolization. A degenerating fibroid can provide a site for bacterial growth and lead to endometritis. In extreme cases, infection may require a hysterectomy. Unintended embolization of another organ or tissue could lead to serious illness.

Recovery

Most women return home the day after the procedure with a prescription for oral pain medication. Pain usually ends within a day or two, but in some women it may last up to a few weeks.

Monitor your recovery for potential complications:

Vaginal discharge
You might have a mucus-like vaginal discharge after uterine artery embolization that clears without treatment. In a few women, remnants of fibroids are passed through the vagina. This is more likely if the fibroids are submucosal, but it can also occur with intramural fibroids. The discharge isn't dangerous and usually stops on its own. Rarely, women need hysterectomies after uterine artery embolization treatment to make sure that no remnants remain. You can expect to resume your normal routine in about two weeks.

Infection
Return to your obstetrician-gynecologist or primary care doctor for a follow-up examination within four weeks of the procedure to make sure there's no infection. Signs and symptoms of infection include fever, chills and pain.

You'll likely undergo a series of ultrasound or magnetic resonance imaging (MRI) examinations over the next year to monitor shrinkage or other changes in the fibroids or your uterus. Doctors usually schedule the first ultrasound examination at three months to allow time for fibroids to shrink. Late infections and vaginal discharge have occasionally been reported up to a year after the procedure.

Menstruation and menopause
Your menstrual period will probably resume within a few months. A small number of women, however, enter menopause after the procedure. The risk appears highest among women age 45 and older. Some embolic agents may pass from branches of the uterine artery to branches of the ovarian artery at areas where the two arterial systems connect. The emboli presumably travel through branches of the ovarian artery to your ovaries. Women who are near menopause (perimenopause) are especially vulnerable to a drop in blood flow. Occasionally disruption of blood supply to the ovaries can lead to menopause. If so, you might be at increased risk of entering menopause after uterine artery embolization.

For women who desire future fertility, uterine artery embolization needs to be carefully considered. Although the risk of entering menopause following the procedure is low, subtle ovarian damage may make getting pregnant more difficult. There also may be an increased risk of pregnancy complications, especially involving abnormal placement of the placenta. Still, despite these concerns, many women have had successful pregnancies following uterine artery embolization.

Common concerns about uterine artery embolization

You may have additional concerns about uterine artery embolization, including long-term complications. Discuss any concerns you have directly with your doctor.

Radiation exposure
Uterine artery embolization exposes your ovaries to radiation for imaging, about the same amount as two barium enemas performed to examine your colon. Proper technique is critical to minimize radiation.

Infections and scar tissue
Some doctors who perform uterine artery embolization say that it isn't the best treatment for large submucosal and subserosal fibroids or for fibroids that hang from a stalk (pedunculated). Others report satisfactory results with uterine artery embolization for women with these types of fibroids. Those who are concerned say that a pedunculated fibroid hanging from the uterine cavity could detach from your uterus after treatment, be too large to exit through your vagina and cause infection. Uterine artery embolization for subserosal fibroids may result in the formation of adhesions, bands of scar tissue between pelvic organs. But surgical treatment of fibroids, such as myomectomy, also carries this risk.

Reason to avoid this procedure

Don't undergo uterine artery embolization if you have:

• A history of pelvic radiation
• A history of kidney failure
• When cancer is a possibility
• An active, recent or chronic pelvic infection
• Poorly controlled diabetes
• Inflammation of the blood vessels (vasculitis)
• A bleeding disorder
• A severe allergy to contrast material containing iodine

Discuss uterine artery embolization with your obstetrician-gynecologist, primary care doctor or an interventional radiologist.

Pros and cons

Uterine artery embolization may or may not be the best option for you. Your preferences and concerns play a large role in determining what's best. Before deciding whether to undergo this procedure, consider these points: