A single copy of this article may be reprinted for personal, noncommercial use only.
Uterine artery embolizationBy Mayo Clinic staff
Original Article: http://www.mayoclinic.com/health/uterine-artery-embolization/MY00502
Uterine artery embolization is a minimally invasive treatment for uterine fibroids, noncancerous growths in the uterus. 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.
Interventional radiologists usually perform uterine artery embolization. This type of doctor uses imaging techniques to guide procedures that would be impossible with conventional surgery. Some specialists in obstetrics and gynecology also have training in uterine artery embolization.
Why it's done
You might choose uterine artery embolization if you are premenopausal and:
- 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
Uterine fibroids can cause severe symptoms in some women, including heavy bleeding, pelvic pain and an enlarged abdomen. Uterine artery embolization destroys fibroid tissue and eases these symptoms — especially heavy bleeding and abdominal swelling — and provides an alternative to surgery to remove fibroids (myomectomy) or surgery to remove your uterus (hysterectomy). The procedure causes fibroids to shrink and soften, but it doesn't make them disappear.
Uterine artery embolization takes advantage of physiological changes caused by uterine fibroids. A uterus with fibroids 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 the growths. Doctors believe that most normal uterine tissue isn't harmed, in part because it gets blood from additional arteries, which are referred to as collateral circulation.
Major complications occur rarely in women undergoing uterine artery embolization. These may include:
- Infection. A degenerating fibroid can provide a site for bacterial growth and lead to infection of the uterus (endomyometritis). Many uterine infections can be treated with antibiotics, but in extreme cases, infection may require a hysterectomy. Serious infections appear to be more likely when the fibroid is located on the inside of the uterus (submucosal fibroid).
- Damage to other organs. Unintended embolization of another organ or tissue could lead to serious illness. Even when embolization is performed correctly, damage to the ovaries can occur. This could result in your periods stopping — rare if you're age 40 or younger but more common if you're age 50 or older when you have the procedure done.
- 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.
- Scar tissue. Uterine artery embolization for fibroids that project toward the outside of your uterus 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.
- Possible problems in future pregnancies. Women can and do have healthy pregnancies following uterine artery embolization. However, some evidence suggests pregnancy complications, including abnormalities of the placenta attaching to the uterus, may be increased following the procedure.
Medical opinion is mixed about whether uterine artery embolization is a good treatment choice for large fibroids projecting into the uterine cavity or outside the uterus or for pedunculated fibroids, which hang from a stalk. A specific concern is that a pedunculated fibroid hanging from the uterine cavity could detach from your uterus after uterine artery embolization. A detached fibroid retained in the uterus could lead to infection.
Reasons to avoid this procedure
Don't undergo uterine artery embolization if you have:
- A history of pelvic radiation
- A history of kidney failure
- Possible pelvic cancer
- 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
- A desire to optimize chances for pregnancy
Discuss uterine artery embolization with your obstetrician-gynecologist, primary care doctor or an interventional radiologist.
How you prepare
On the evening before the procedure, don't eat or drink after midnight. If you're taking medications, ask your doctor if you should stop taking them before or after the procedure.
In the radiology procedure room, a staff member places a needle attached to a slender tube into a vein in your arm to give you fluids, anesthetics, antibiotics and pain medications. A thin tube placed into your bladder through your urethra (urinary catheter) keeps your bladder empty.
What you can expect
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. Regional anesthesia blocks pain, yet leaves you conscious and able to communicate.
During the procedure
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 (6 millimeters) in the skin over your femoral artery, which passes lengthwise through your groin, then inserts a catheter into the artery and guides the catheter to one of the two uterine arteries. An injected contrast fluid, usually containing iodine, flows into the uterine artery and its branches and makes them visible on the fluoroscope's monitor.
The contrast material makes the fibroids "light up" more brightly than other uterine tissue because of increased fibroid blood flow. The radiologist identifies and maps the vessels leading to the fibroids, then injects the branches with tiny particles made of plastic or gelatin. After injecting more contrast into the uterine artery, the radiologist checks additional images to make sure that blood is no longer reaching the fibroids. The same steps are then repeated in the second uterine artery. Generally, the radiologist can access both uterine arteries through one incision.
After the procedure
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.
Monitor your recovery for potential complications:
- 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.
Studies have shown that uterine artery embolization reduces symptoms such as heavy bleeding, urinary incontinence and abdominal enlargement in 75 percent or more of women who undergo the procedure to treat their fibroids. However, many of these studies focused on small groups of women and lacked long-term follow-up of study participants.
Five years after treatment with uterine artery embolization, more than 75 percent of women maintain symptom control. These results are comparable to that of myomectomy, in which the fibroids are surgically removed and the uterus repaired.
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. The cause may be that the ovaries and uterus share some blood vessels and when the uterine arteries are embolized, disruption of the ovarian blood supply can result. If you're nearing menopause (perimenopausal), such a disruption could lead to menopause.
If you want to have children or think you might want to at some point, talk to your doctor about how uterine artery embolization might affect your fertility. 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. Despite these risks, many women have had successful pregnancies following uterine artery embolization.
- The American College of Obstetrics and Gynecologists. Alternatives to hysterectomy in the management of leiomyomas. Obstetrics & Gynecology. 2008;112:387.
- Haney AF. Leiomyomata. In: Gibb RS, et al. Danforth's Obstetrics and Gynecology. 10th ed. Philadelphia, Pa.: Lippincott Williams & Wilkins; 2008:916.
- Kim D, et al. Uterine leiomyoma (fibroid) embolization. http://www.uptodate.com/home/index.html. Accessed Feb. 16, 2011.
- Kim MD, et al. Long-term results of symptomatic fibroids treated with uterine artery embolization: In conjunction with MR evaluation. European Journal of Radiology. 2010;73:339.
- Marshburn PB, et al. Uterine artery embolization as a treatment option for uterine myomas. Obstetrics and Gynecology Clinics of North America. 2006;33:125.
- Walker WJ, et al. Long-term follow up of uterine artery embolization - an effective alternative in the treatment of fibroids. BJOG. 2006;113:464.
- Narayan A, et al. Uterine artery embolization versus abdominal myomectomy: A long-term clinical outcome comparison. Journal of Vascular and Interventional Radiology. 2010;21:1011.
- The Practice Committee of the American Society for Reproductive Medicine. Myomas and reproductive function. Fertility and Sterility. 2008;90(suppl):S125.
- Van der Kooij SM, et al. Uterine artery embolization vs. hysterectomy in the treatment of symptomatic uterine fibroids: 5-year outcome from the randomized EMMY trial. American Journal of Obstetrics and Gynecology. 2010;203:105.e1.
- Pron G, et al. Pregnancy after uterine artery embolization for leiomyomata: The Ontario multicenter trial. Obstetrics & Gynecology. 2005;105:67.