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ARTICLES
UTERINE FIBROID EMBOLIZATION
Known medically as uterine artery embolization, this is a fundamentally
new approach to the treatment of fibroids that blocks the arteries
that supply blood to the fibroids. It is a minimally invasive procedure,
which means it requires only a tiny nick in the skin, and is performed
while the patient is conscious but sedated — drowsy and feeling no
pain.
Photo courtesy of SCVIR |
Fibroid embolization is usually done in a hospital by an interventional
radiologist, a physician who is specially trained to perform this
and other minimally invasive procedures.
The interventional radiologist makes a small nick in the skin (less
than one-quarter of an inch) at the crease at the top of the leg to
access the femoral artery, and inserts a tiny tube (catheter) into
the artery. Local anesthesia is used so the needle puncture is not
painful. The interventional radiologist steers the catheter through
the artery to the uterus using X-ray imaging (fluoroscopy) to guide
the catheter's progress. The catheter is moved into the uterine artery
at a point where it divides into the multiple vessels supplying blood
to the fibroids. An arteriogram (a series of images taken while radiographic
dye is injection) is performed to provide a road map of the blood
supply to the uterus and fibroids.
The interventional radiologist slowly injects tiny plastic (polyvinyl
alcohol or PVA) or gelatin sponge particles the size of grains of
sand into the vessels. The particles flow to the fibroids first, wedge
in the vessels and cannot travel to other parts of the body. Over
several minutes, the arteries are slowly blocked. The embolization
is continued until there is nearly complete blockage of the blood
flow in the vessel.
Photo courtesy of SCVIR |
The procedure is then repeated on the other side so the blood supply
is blocked in both the right and left uterine arteries. Some physicians
block both uterine arteries from a single puncture site, while others
puncture the femoral artery at the top of both legs. After the embolization,
another arteriogram is performed to confirm the results. The skin
puncture where the catheter was inserted is cleaned and covered with
a bandage.
As a result of the restricted blood flow, the tumor (or tumors) begin
to shrink.
Fibroid embolization usually requires a hospital stay of one night,
although some women do go home the same day. About six to eight hours
of bed rest is typical after the procedure. Pain-killing medications
and drugs that control swelling typically are prescribed following
the procedure to combat cramping, which is a common side effect. Fever
also is an occasional side effect, and is usually treated with acetaminophen.
Total recovery generally takes one to two weeks, but can take longer.
While embolization to treat uterine fibroids has been performed for
more than six years, embolization of arteries in the uterus is not
new. The procedure has been used successfully by interventional radiologists
in uterine arteries for more than 20 years to treat heavy bleeding
after childbirth. Today, fibroid embolization is being performed at
hospitals and medical centers across the country, in Canada and around
the world. As of the end of 1998, about 1,500 to 2,000 fibroid embolization
procedures had been done world-wide.
Expected Results
Fibroid embolization was first studied in the United States by Scott
Goodwin, M.D., of the University of California Los Angeles, who reported
his results in 1997. Since that time, a number of interventional radiologists
have studied the procedure and have reported similar success with
the technique reported by Dr. Goodwin.
The results of studies that have been published or presented at scientific
meetings report that 78 percent to 94 percent of women who have the
procedure experience significant or total relief of pain and other
symptoms, with the large majority of patients considerably improved.
The procedure has been successful even when multiple fibroids are
involved. Most patients have rated the procedure as "very tolerable."
The expected average reduction in the volume (size) of the fibroids
is 50 percent after three months, with a reduction in the overall
size of the uterus of about 40 percent.
The long-term outcome is not known as only short-term follow-up is
available. It is not yet known if the fibroids can re-grow, however
no recurrences have occurred in women who have been followed for up
to six years. (See Bibliography for additional information.)
Fertility
The majority of patients who have fibroid embolization are finished
with childbearing and few women have tried to subsequently become
pregnant, making fertility difficult to study. More than a dozen pregnancies
have been reported, however, and patients who have had uterine arteries
embolized for other reasons, such as bleeding after childbirth, have
successfully become pregnant. Research is underway to study this issue.
There have been a few women whose menstrual periods have stopped after
the procedure, which would result in infertility. See side effects/complications
for a further discussion of this topic.
Side Effects/Complications
Fibroid embolization is considered to be very safe, however, there
are some associated risks, as there are with almost any medical procedure.
Most patients experience moderate to severe pain and cramping in the
first several hours following the procedure; some experience nausea
and, possibly, fever. These symptoms can be controlled with appropriate
medications. Most symptoms are substantially improved by the next
morning, however, there may be some pain and cramping for several
days or more. Many women report returning to work within a week of
having the procedure.
Complications occur in fewer than 3 percent of patients. Serious possible
complications include injury to the uterus from decreased blood supply
or infection. This is uncommon and hysterectomy to treat either of
these complications occurs in less than 1 percent of patients. Injury
to other pelvic organs is possible but has not yet been reported and
the chance of other significant complications is less than 1 percent.
Long-term complications are not expected, although questions about
potential side effects remain.
It is not known what effect, if any, fibroid embolization has on the
menstrual cycle. The overwhelming majority of women who have had embolization
have had decreased bleeding with normal menstrual cycles. There have
been a few women, most of whom are near the age of menopause, whose
menstrual periods have stopped after the procedure. It is uncertain
whether these cases are a result of decreased ovarian function resulting
from the procedure. Based on this limited information, it appears
that the procedure may cause a loss of menstrual cycles (premature
menopause) in a very small number of patients.
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