Embolization is a technique that was invented to stop bleeding. A tiny catheter (a thin, hollow tube) is inserted into a bleeding vessel, and material is injected through the catheter. The material is carried by flowing blood until it lodges at the bleeding site. As the material builds up, it acts like the branches of a beaver's dam. When enough material is in place, the flow of blood stops.

Uterine artery embolization (UAE) is a procedure that offers an alternative to traditional surgical removal of uterine fibroids. The procedure may also be referred to as uterine fibroid embolization (UFE).

• Infection. This is the most serious, potentially life-threatening complication of UFE. In rare cases, hysterectomy is needed to treat an infected uterus.
• Premature menopause. This seems more likely to happen to women over 40 years of age than in younger women.
• Loss of menstrual periods (amenorrhea).
• Scar tissue formation (adhesions).
• Pain that lasts for months.

• You have severe pain or heavy bleeding from uterine fibroids
• Surgery is too risky for you or you want to retain your uterus
• Optimizing a future pregnancy is not your chief concern

Image-guided, minimally invasive procedures such as catheter embolizations should be performed by a specially trained interventional radiologist in an interventional radiology suite or occasionally in the operating room.

Prior to your procedure, ultrasound, computed tomography (CT) or magnetic resonance imaging (MRI) may be performed. You will be positioned on the examining table.

You may be connected to monitors that track your heart rate, blood pressure and pulse during the procedure. A nurse or technologist will insert an intravenous (IV) line into a vein in your hand or arm so that sedative medication can be given intravenously. Moderate sedation may be used. As an alternative, you may receive general anesthesia.

The area of your body where the catheter is to be inserted will be shaved, sterilized and covered with a surgical drape. A very small nick is made in the skin at the site. Using image-guidance, a catheter (a long, thin, hollow plastic tube) is inserted through the skin to the treatment site. A contrast material then is injected through the catheter and a series of x-rays are taken to locate the exact site of bleeding or abnormality. The medication or embolic agent is then injected through the catheter. Additional x-rays are taken to ensure the loss of blood flow in the target vessel or malformation.

At the end of the procedure, the catheter will be removed and pressure will be applied to stop any bleeding. The opening in the skin is then covered with a dressing. No sutures are needed. Your intravenous line will be removed. If you are being treated for an intracranial arteriovenous malformation (AVM), a small test injection of embolic agent is done first and neurological function will be tested to ensure no important brain area will be affected by the embolization. Then, vessels feeding the AVM will be injected with the embolic material. Large AVMs may require multiple embolization procedures on separate days for complete treatment.

For example, two or three treatments may be given at intervals of two to six weeks. You can expect to stay in bed for six to eight hours after your procedure. The length of the procedure varies from 30 minutes to several hours depending on the complexity of the condition.

In the recovery room, staff members monitor your condition and give you 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.

To manage the pain, you receive medication through the catheter in your vein. Usually, the medication will be an opioid, such as morphine, although nonsteroidal anti-inflammatory drugs (NSAIDs) may be added or used instead. 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 — low-grade fever, pain, extreme fatigue, nausea and vomiting — is common after uterine artery embolization. Doctors believe that chemicals released by degenerating fibroids stimulate inflammation, causing these symptoms. Although post-embolization syndrome usually resolves spontaneously, it's important to rule out endomyometritis, a serious complication marked by delayed pain, a rise in the white blood cell count and a pus-like vaginal discharge. Doctors treat endomyometritis with intravenous (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.

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.

• Vaginal discharge. You might have a watery or mucus-like vaginal discharge after uterine artery embolization. The discharge should stop without treatment. In a few women, remnants of fibroids are passed through the vagina. The discharge isn't dangerous and usually stops on its own.
• 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 three months after the procedure. Delayed infections and vaginal discharge are sometimes reported up to a year after the procedure.

Possible complications after embolization include abdominal pain, fever, nausea, infection in the liver, gallbladder inflammation, and blood clots in the main blood vessels of the liver. Serious complications are not common, but they are possible.