Uterine Artery Embolization (UAE)
Radiology Specialized Procedures
What are Fibroids?
Fibroids are benign (non-cancerous) tumors of the smooth muscle layer (myometrium) of the uterus. Their medical name is uterine leiomyomas. Other names for fibroids include myomas, myofibromas, fibromas, and fibromyomas.
Fibroid size ranges from tiny to huge (cantaloupe size). Fibroids can increase greatly in size during pregnancy, usually returning to their previous size after pregnancy. Fibroids usually shrink during menopause. Hormone replacement may prevent this improvement, however.
What causes fibroids?
Nobody knows for certain what causes fibroids. Scientific studies suggest that the tendency to form fibroids may be inherited. It is known that hormones affect fibroids. The female hormones estrogen and progesterone both seem to promote the growth of fibroids. Other hormones may also affect fibroids (e.g. growth hormone and prolactin).
How common are fibroids and who gets them?
Fibroids are very common, present in up to 70% of reproductive-age women. Most affected women have multiple fibroids, the average being three to four. Fibroids are usually detected in women in their 30's and 40's. African-American women are two to five times more likely than white women to develop fibroids. Despite containing hormones, oral contraceptives appear to lower rather than raise the risk of fibroids.
What are the symptoms of fibroids?
Most women with fibroids have no symptoms or minor symptoms. About 20% of women with fibroids have severe symptoms--usually heavy menstrual bleeding and/or pelvic pain or pressure. Other symptoms include increased menstrual cramps; pain in the back, flank, or legs; increased urination; constipation; pain with sexual intercourse; and bulging abdomen.
Are fibroids detectable on physical examination?
Yes, during a pelvic examination a physician can feel that the uterus is enlarged. Very small fibroids may not be detectable this way.
Which tests can detect fibroids?
The most common method used to confirm the presence of fibroids is an abdominal ultrasound examination which uses sound waves to make pictures of the uterus and other internal structures. Sometimes a special ultrasound probe is placed in the vagina to see the uterus even better.
Fibroids can also be seen using magnetic resonance imaging (MRI) and computed tomography (CT). To check for submucosal fibroids, those just beneath the inner lining, a gynecologist can pass a slender tube through the vagina and cervix into the uterus and view the uterine cavity; this procedure is called diagnostic hysteroscopy.
How are fibroids treated?
Most fibroids cause no symptoms and therefore require no treatment. For symptomatic fibroids, however, there are three main approaches: taking medications; surgery to remove the fibroids or the whole uterus; or uterine artery embolization, a relatively new, non-surgical procedure that cuts off the blood supply to the fibroids, causing them to shrink.
Treatment with medications such as birth control pills or GnRH analogs (a class of drugs which lowers estrogen production; Lupron is an example) results in temporary shrinkage of fibroids. However, fibroids return to their original size within months of stopping the medicine. These medications also have undesirable side effects, such as bone loss and hot flashes, which limit long-term use.
Several types of surgery can be done for fibroids. The most common method is to remove the whole uterus (hysterectomy) either through open surgery through the abdominal wall, through the vagina, or through small incisions using special instruments (laparoscopically). About 200,000 hysterectomies for fibroids are done each year in the United States, making hysterectomy one of the most frequent operations.
Removal of just the fibroids, but not the uterus itself, is called myomectomy. This approach can help women preserve the ability to have children. Like hysterectomy, myomectomy can be performed several different ways including open, laparoscopically, and hysteroscopically. Surgical approaches usually require general anesthesia and a long recovery period (weeks to months). Complications can include adhesions, blood loss, infection, and damage to adjacent structures.
Uterine artery embolization is a fairly new method to treat fibroids and is described next.
What is embolization?
The word embolus (emboli for plural) refers to a clot or plug which comes from a source in a blood vessel and flows downstream until it lodges in a smaller vessel, blocking it off. Each blood vessel supplies oxygen and nutrients to a certain amount of tissue. An embolus cuts off the blood supply to that region of tissue, which then dies. For over 30 years, interventional radiologists have used controlled emboli to selectively stop dangerous or uncontrollable bleeding or to kill undesirable tissue, such as tumors, without the need for surgery or in places where surgery is difficult or ineffective.
How is uterine artery embolization done?
The procedure of embolization in considered minimally invasive. This means that it is all done through a very small incision, usually not larger than the width of a pencil. A patient does not need general anesthesia for this type of procedure; it can be done without pain by using local numbing medicine and some sedation (medicine that causes drowsiness and relieves anxiety).
Embolization is performed by interventional radiologists. These are highly specialized doctors who are trained in imaging and minimally invasive procedures. They perform embolization using a "catheter" which is a long, very skinny, soft, flexible, plastic tube that they place into a large blood vessel, usually in the groin, through the tiny skin incision. Under x-ray guidance the catheter is advanced until its tip is exactly in the desired blood vessel -- in this case, the uterine artery.
At this point the radiologist will perform an angiogram. This is done by injecting X-ray dye through the catheter while taking x-ray images. The angiogram gives a map of the uterine artery; this lets the radiologist determine which branches supply the fibroids.
Once the tip of the catheter is in the desired branch, the radiologist injects tiny plastic (PVA) particles the size of grains of sand which flow to the fibroids and block the little arteries that supply them. The catheter is removed and a bandaid placed on the groin.
The procedure causes pelvic pain, which is well controlled with intravenous medication. This pain usually subsides enough within 6 to 8 hours that the patient can go home, taking pain medicines by mouth. In some patients, the pain takes longer to subside, and an overnight hospitalization is necessary (so that pain medicine can be given intravenously). Cramping and some pain are common for one to two weeks after the procedure, but usually respond well to oral pain-killing medication. Fever is less common and is usually controlled by acetaminophen (e.g. Tylenol). Nausea and fever are also possible.
What are the risks and side effects?
Complications of uterine artery embolization are uncommon, occurring in less than 5% of patients. As with all minimally invasive procedures, there is a chance of bleeding, infection, injury to blood vessels, need for further procedures, and unforeseen complications. In rare cases, infection or decreased blood supply to the uterus may require hysterectomy.
Some women develop a "post-embolization syndrome" (See subsequent Frequently Asked Questions section).
The long-term effect of uterine artery embolization on pregnancy and the menstrual cycle is not fully known. Most women treated with this technique so far are no longer interested in having children and have not tried to become pregnant, so it is not yet known what percentage of women who have this procedure will be able to become pregnant should they so wish. Some women who have had the procedure have gone on to conceive and deliver. With time and further study, this issue will be better clarified. Similarly, the effect of uterine artery embolization on the menstrual cycle is not fully known. Of the thousands of women treated with this procedure, nearly all have continued their normal menstrual cycle except with decreased bleeding. However, a very small number have become irregular or even stopped having periods. Although this may be coincidence, right now it remains possible that uterine artery embolization may cause premature menopause in a very small number of patients. Studies are being done to better answer these questions.
How much improvement can be expected?
Uterine artery embolization is successfully performed 95-100% of the time, from a technical standpoint, with marked improvement of symptoms reported in 80-90% of cases. The Society of Cardiovascular and Interventional Radiology (SCVIR. org) reports that "the world-wide clinical success rate, defined as improvement in symptoms such that the patient has not required further operative therapy, is 85 percent. The average reduction in uterine volume ranges from 36 percent to 69 percent with reported follow-up ranging from 2-60 months. As many as 10 percent of patients subsequently require surgery, primarily due to treatment failure."
Uterine artery embolization at Loma Linda University Medical Center is coordinated by the Marilyn Jones in department of radiology, telephone number (909) 558-4370. The outline below serves as a guide to the steps our patients go through at LLUMC.
- Evaluation by a gynecologist
- History and physical
- Possible endometrial sampling/hysteroscopy/laparoscopy with biopsies to exclude cancer
- Pap smear within last 6 months
- Ultrasound within last 6 months
- Pregnancy test
- Nothing to eat or drink after midnight
- Check in at the preoperative testing area (PATS) on the 2nd floor at scheduled time
- Change into gown, have IV placed
- Have final questions answered, give consent for procedure
- Be taken to interventional radiology suite, meet staff
- Receive sedation
- Procedure performed, usually takes about 2 hours
- Recover, usually 6-8 hours
- Usually go home same day (someone else will need to drive), occasionally stay overnight and go home next morning
- Recovery continues at home
- Many resume full activities by the end of one week
Physician follow-up (gynecologist)
- One week
- 3 months
- 6 months
- Then annually
- 6 weeks
- 6 months
Who is a candidate for uterine artery embolization?
Candidates for uterine artery embolization should meet the following criteria:
- presence of significantly symptomatic fibroids
- abnormal uterine bleeding
- pelvic pain
- massive fibroids causing enlarged uterus with pressure on bladder or rectum
- not pregnant
- no active pelvic infection
- no uterine malignancy
What is the relationship of fibroids to cancer?
Fibroids are common, benign (i.e. non-cancerous) tumors. There are, however, relatively rare cancers, (leiomyosarcoma and endometrial cancer) which can mimic the presentation of fibroids. Uterine artery embolization is not the correct treatment for these cancerous processes. Gynecologists can recognize situations, such as rapidly enlarging uterus or certain bleeding patterns, which warrant extra testing to make sure that the problem is really fibroids rather than a malignant process before proceeding with treatment. Such testing typically consists of obtaining a tissue sample from the inner lining and/or wall of the uterus.
Does uterine artery embolization affect the ability to have more children?
The effect of uterine artery embolization on pregnancy is not fully known. Most women treated with this technique so far are no longer interested in having children and have not tried to become pregnant, so it is not yet known what percentage of women who have this procedure will be able to become pregnant should they so wish. Some women who have had the procedure have gone on to conceive and deliver.
Does uterine artery embolization affect the menstrual cycle?
The effect of uterine artery embolization on the menstrual cycle is not fully known. Of the thousands of women treated with this procedure, nearly all have continued their normal menstrual cycle, except with a decreased amount bleeding. However, a very small number of patients have gone on to become irregular or have even stopped having periods. Although this may be coincidence, right now it remains possible that uterine artery embolization may cause premature menopause in a very small number of patients. Studies are being done to better answer these questions.
What is "post embolization syndrome?"
When tissue dies, it releases substances that activate the body's defense systems. One of the ways this activation shows up is as increased body temperature. This is what happens when fibroid tissue dies as a result of uterine artery embolization. In about twenty percent of patients, this process is more pronounced, with fevers up to 102-103 degrees Fahrenheit. Due to individual variation, this phenomenon may show up at any time during the first ten days and last for seven to ten days. Usually, the syndrome is associated with the embolization of large fibroids and, if it happens, typically begins within 36 hours of the procedure. Such fevers should be reported to the physician, but the treatment is usually confined to a simple course of anti-inflammatory medication such as ibuprofen. The fevers of post embolization syndrome are not caused by infection.
Uterine artery embolization at Loma Linda University Medical Center is coordinated by Norma Cross in the department of radiology. Her telephone number is (909) 558-4769. This procedure is performed at this institution by the following interventional radiologists: Douglas C. Smith, MD, and Jason C. Smith, MD.
If you do not have a gynecologist or your gynecologist is unfamiliar with uterine artery embolization, we are pleased to recommend the following Loma Linda gynecologists:
Kevin Balli, MD
Danielle Mason, MD
Appointments with these physicians can be arranged by calling (909) 558-2806. (Linda Mohr 44653)