MGH Department of Radiology - Uterine Fibroid Embolization

What are fibroids?
What are the different types of fibroids?
What sort of symptoms can fibroids cause?
When should fibroids be treated?
What is Uterine Artery Embolization for fibroid reduction?
Who performs uterine artery embolization?
How is uterine artery embolization performed?
How can a woman expect to feel after having uterine artery embolization for fibroid reduction?
How much will the fibroids shrink and how long does this take?

What are fibroids?

Fibroids are the most common tumor of the female genitourinary tract. Fibroids are benign tumors of the uterine muscle which form when the muscle cells depart from their normal alignment and begin to grow as circular masses. The medical term for fibroid is leiomyoma. Studies suggest that fibroids are very common and are probably present to some degree in the majority of women. The exact causes of fibroid are not well understood, although estrogen, progesterone, and growth hormone appear to promote fibroid growth.

What are the different types of fibroids?

Fibroids tend to be classified according to their location. Intramural fibroids are buried within the wall of the uterus, while pedunculated fibroids hang from a stalk and may be intracavitary (protruding into the endometrial cavity) or hang off the outside of the uterus. Cervical fibroids are imbedded in the cervix, subserosal fibroids grow just beneath the outer surface of the uterus, and submucosal fibroids grow just beneath the inner endometrial lining of the uterus. Occasionally, intraligamentous fibroids extend into the ligaments which surround and support the uterus.

What sort of symptoms can fibroids cause?

Small fibroids rarely cause any symptoms at all unless they are very numerous. However, when fibroids become large in size, they can press upon nearby structures such as the bladder or bowel and cause pelvic pain, pressure, or urinary symptoms including frequent need to void, urgency, and even obstruction of the kidneys. Submucosal fibroids growing near the uterine lining may cause heavy menstrual bleeding. Uncommonly, fibroids may impair fertility or complicate pregnancy by obstructing the fallopian tubes, occupying too much space in the uterus, or by diverting blood flow away from the placenta. In addition to physical symptoms, large fibroids can make a woman appear pregnant when she is not, a situation which may be psychologically distressing.

When should fibroids be treated?

Fibroids which are not causing significant symptoms and are smaller in size than a twelve week gestation uterus do not need to be removed and may be followed clinically. Fibroids which cause symptoms such as pain, pressure, bleeding or impaired fertility should be considered for treatment.

What is Uterine Artery Embolization for fibroid reduction?

Uterine fibroid procedure

The uterus gets its blood supply mainly from the uterine arteries which are a pair of blood vessels running up the sides of the uterus. Fibroids derive almost all their blood supply from branches of the uterine arteries. When the uterus contains large fibroids, the uterine arteries enlarge significantly in response to the increased blood flow. In the past two years, there has been growing interest in treating fibroids by blocking the uterine arteries with small particles, a process known as embolization. These particles are made of inert materials and do not react in the body. The reasoning behind the concept of uterine artery embolization is that one could shrink fibroids by depriving them of their blood supply.

Who performs uterine artery embolization?

Uterine artery embolization is a procedure which is performed by a vascular interventional radiologist. This type of medical specialist is often also referred to as an angiographer. A vascular interventional radiologist is a doctor who is a specialist in performing procedures which require manipulation of catheters inside the blood vessels as well as inside various other parts of the body. These catheter based procedures are performed under x-ray guidance, and vascular interventional radiologists have extensive training in the use of x-ray equipment, x-ray dye, and image interpretation.

How is uterine artery embolization performed?

Uterine fibroid procedure

In order to safely deliver the particles to the uterine arteries, the physician first punctures the artery near the groin under local anesthesia and inserts a small tube called a catheter. The catheter is then threaded under x-ray guidance into the pelvic vessels and X-ray dye is injected to help locate the uterine arteries. This step is called an angiogram. The catheter is then threaded into one uterine artery and embolization particles are injected into the artery until blood flow slows to a stop. The catheter is then repositioned into the other uterine artery and the process is repeated. When the embolization is complete on both sides, the catheter is removed and pressure is applied to the puncture site until all bleeding stops. The patient must then remain at bedrest for 6 hours to allow the puncture site to heal sufficiently.

How can a woman expect to feel after having uterine artery embolization for fibroid reduction?

All women who undergo uterine artery embolization will experience varying degrees of pelvic pain and discomfort. This discomfort is related to the fact that the fibroid tissue is deprived of blood flow and oxygen and is dying. The discomfort is most severe in the first 24 hours, and gradually resolves over the following one to two weeks. During this time, some women may also experience mild to moderate fatigue. At Massachusetts General Hospital, all women undergoing the procedure are admitted to the hospital overnight to insure that they receive adequate pain control and are comfortable following the procedure. Patients are discharged home with prescriptions for both narcotic pain medication to be used as needed and ibuprofen to help control uterine cramping. The Nurse Practitioner assigned to you will follow up with frequent telephone calls and keep in close contact with you.

How much will the fibroids shrink and how long does this take?

The fibroids will shrink on average approximately 40-45% over the first six months. This reduction may be greater in some patients and less in others. Bleeding symptoms usually resolve immediately after the procedure.

For more information regarding Uterine Fibroid Embolization, please call the Nurse Practitioner at 617-726-8314.