Focused ultrasound ablation

MRI-guided focused ultrasound, approved by the Food and Drug Administration in October 2004, is a newer treatment option for fibroids. Unlike hysterectomy, myomectomy and renal artery embolization, focused ultrasound ablation is noninvasive. This procedure also preserves your uterus.

The procedure is performed while you're inside a magnetic resonance (MR) scanner that has an ultrasound transducer within the table you lie on for the procedure. During the procedure, MR images give the doctor the precise location of your fibroids to be treated. Then the ultrasound transducer is used to send focused sound waves (sonications) into the fibroid to heat and destroy small areas of tissue. Each sonication lasts approximately 20 seconds. During and after each portion of the fibroid is heated, magnetic resonance imaging (MRI) is used to monitor tissue temperature and determine if the tissue has been heated enough to achieve the desired results. The process is repeated until most of the fibroid has reached a temperature that should destroy the tissue. A pelvic MRI is typically performed before treatment to determine whether you're a good candidate for this procedure.

What to expect

A doctor performs focused ultrasound treatment in an MR scanning room. It's an outpatient procedure.

At the hospital, you're given a gown and robe to wear. Before entering the MRI scanning room, remove all accessories — watch, jewelry, hairpins, wigs, dentures and hearing aids — that may contain metal or electronics. Metal objects may interfere with the magnetic field used during the exam, affecting the quality of the MR images. The magnetic field may also damage electronic items. Be sure to tell the technologist if you have any metal or electronic devices inside your body as well — metallic joint prostheses, artificial heart valves, implanted electronic devices, cochlear implants, body piercings or magnets in your dentures (most dental fillings don' t cause a problem). The presence of metal inside your body may be a safety hazard or affect a portion of the MR image.

Shortly before the procedure begins, an intravenous line will be placed in one of your veins, usually on the back of your hand. The doctor or nurse will use this line to give you medication and to inject contrast material for MR images taken right after the treatment.

You'll also have a urinary catheter inserted into your bladder. This is done to keep the bladder empty during your treatment.

Typically, it takes 50 to 80 sonications to destroy the core of a fibroid. However, depending on the size and number of fibroids you have, more sonications or a second treatment may be necessary. As your treatment progresses, the MR images allow doctors to evaluate the effects and define areas that need additional treatment. In the future, it is hoped that improved technology will shorten the length of each treatment and reduce the number of sessions required.

After the procedure, your body naturally absorbs a small portion of the ablated tissue over a period of months. Symptoms usually subside or improve significantly in three to six months.

How do you prepare?
You will be asked to fast the day of the treatment. You will also need to shave the lower abdomen between your pubic bone and bellybutton just before the treatment.

How is it done?
During the procedure, you lie on your stomach on a movable table that slides into the opening of the MRI scanner. A technologist makes sure that you're comfortable inside the scanner. He or she leaves the room and monitors you from an adjoining room. You'll be able to talk with him or her by microphone. Because the internal part of the magnet produces repetitive tapping, thumping sounds and other noises, earplugs will be provided to help block the noise.

The treatment itself takes about three to four hours, but can vary depending on the size and number of fibroids you have.

Before any ultrasound pulsations are delivered, you will be given medication intravenously to help you relax and relieve possible heat and cramping discomfort. After each sonication, you will be asked about your level of discomfort so that your medication can be adjusted or other changes can be made if necessary.

After the procedure
If you live within a short distance (usually about 40 miles) of the medical facility, you should be able to go home as soon as you've rested for a short time after the procedure. If you're farther from home, you can arrange to stay in town and return home on the following day. You will need a friend or family member to be with you and drive for the first 24 hours after your treatment, due to the medications you receive during the treatment.

When you get home, you can resume your normal daily activities. Although rare, pain near the treatment area, nausea and skin burns have been reported after focused ultrasound surgery in some cases. Because the procedure is so new, some complications and side effects may still be unknown.

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• Video: Focused ultrasound for uterine fibroids treatment

Pros and cons

Although focused ultrasound surgery offers many advantages over other fibroid treatment options, it's not the best option for everyone. It may not be a good choice for you if you have fibroids behind heat-sensitive organs, such as your bowel. This treatment isn't intended for women who desire future pregnancy. Long-term effects on a woman's ability to become pregnant and carry a fetus to term have not been studied adequately yet.

Before deciding to use this treatment approach, consider these points: