MR guided Focused Ultrasound Surgery
Overview
MR guided Focused Ultrasound Surgery is a non-invasive, outpatient procedure that employs high doses of focused ultrasound waves (HIFU) to destroy uterine fibroids without harming the surrounding tissues. The procedure is performed in an MRI scanner, which allows the physician to “see” inside the body in order to pinpoint, guide, and continuously monitor the treatment. Imagine using a magnifying glass to concentrate the sun’s energy on a single point in order to produce a flame capable of igniting a leaf. The focused ultrasound energy is directed at a small volume of the fibroid, heating it sufficiently to cause thermal ablation (cell death) without affecting other tissues. Energy pulses are repeated until the entire volume has been treated.
Diseases treated with MR guided Focused Ultrasound Surgery
Magnetic resonance guided focused ultrasound (MRgFUS) may also be used for treating:
- Bone metastasis
- Osteoid osteoma
- Essential tremor
Preparation for MR guided Focused Ultrasound Surgery
If you are a candidate for treatment, magnetic resonance imaging (MRI) or ultrasound of the uterus will be performed. In addition to assessing the size, number, and location of your fibroids, these examinations will aid in treatment planning. Your physician may suggest a pregnancy test. Patients who are pregnant should not undergo the MRgFUS.
Your doctor may want to perform a laparoscopy to examine your uterus directly. If you experience heavy menstrual bleeding, an endometrial biopsy may be performed. Before your procedure, you may be asked to stop taking aspirin, nonsteroidal anti-inflammatory drugs (NSAIDs), or blood thinners. You must inform your physician of any recent illnesses or other medical conditions. The hospital will inform you of the medications you may take the morning of the scheduled procedure, as well as the potential length of your hospital stay.
Procedure
You are given a sedative and pain medication to help you relax prior to treatment. Before beginning treatment, you are made comfortable on a patient table. You undergo treatment while lying on the patient table within the MR scanner. Your clinical team will be in the next room, equipped with a microphone and a speaker for two-way communication. When images are being acquired (scanned) and when the system is sonicating, the physician will inform you (treatment).
It is normal to experience a warming sensation in the pelvic region during treatment. You will be provided with a safety stop button that will allow you to stop the sonication immediately if the treatment becomes painful. The doctor will insert a Foley catheter into your bladder during MRgFUS in order to drain it during treatment. A full bladder will cause the uterus and fibroids to shift position. During treatment, your doctor may inject ultrasound gel into your rectum to move it away from the uterus. You must wear compression stockings to aid in the prevention of deep vein thrombosis (blood clots).
During the 15 to 25 seconds that each sonication lasts, the radiologist monitors the progress and reviews temperature-sensitive images. Typically, the procedure requires fifty or more sonications. Depending on the size and number of fibroids to be treated, the entire process typically takes several hours. You remain conscious throughout the procedure and provide feedback to the physician.
After the procedure, you will rest in the clinic for a few hours while the sedative takes effect. You can return home the same day, but if necessary, you can stay in the hospital for one night. Following treatment, you should be able to resume your normal daily activities within two days. In the days following the procedure, you may experience abdominal or pelvic pain. This is typically treatable with over-the-counter medications.
MRgFUS may occasionally cause redness on the abdominal skin, skin burns, bleeding, and/or bruising immediately following treatment. Typically, these effects disappear within a week or two. After the procedure, irregular menstrual bleeding may persist for a few weeks. Within the first six months following MRgFUS, the majority of patients’ fibroids-related symptoms improve significantly. Your body will gradually and naturally absorb the treated tissue over months or even years. Following treatment, patients should continue to experience symptom relief for three years.
Benefits of MR guided Focused Ultrasound Surgery
- The percentage of fibroid volume that is ablated determines the duration of symptomatic relief for the majority of women who are suitable candidates for this procedure
- There is a low risk of complications with this procedure
- MRgFUS may provide rapid relief from the symptoms of uterine fibroids without the need for invasive surgery
- The procedure is non-invasive (i.e., it does not leave surgical scars), can be performed on an outpatient basis, has a brief recovery period, and may permit a quick return to normal activities
- The uterus is preserved by MRgFUS. Following MRgFUS treatment for uterine fibroids, a number of patients have conceived successfully. Doctors continue to study the long-term effects of MRgFUS on a patient’s ability to conceive and carry a child to term. Because MRgFUS has not been utilized as long as other fibroid treatments, there are fewer long-term data on its safety, efficacy, and effects on fertility and pregnancy
- MRI is a non-invasive imaging method that does not involve radiation exposure
Few contraindications exist. Certain implanted devices, such as pacemakers and neurostimulators, may disqualify a candidate. To prevent injury to the patient from the MR’s powerful magnetic field, any metallic implants must be non-magnetic. Pregnant women are ineligible for treatment with this device. If the fetus is in or near the location of the focused MRgFUS beam, the effect of MRgFUS could result in permanent injury or death.
