The purpose of this article is to review the literature regarding UAE and its development, techniques, indications, results, and complications.
was a Cardiovascular Interventional Radiology fellow at New York
Presbyterian Hospital, Cornell Medical Center, New York, NY. He is
currently an Assistant Professor at the University of Dentistry of
New JerseyNew Jersey Medical School.
are Professors and
is the Chief of the Cardiovascular Interventional Radiology Section
at New York Presbyterian Hospital, Cornell Medical Center, New
Recently, uterine artery embolization (UAE) has received
much attention in both the scientific literature and the lay
press as a minimally invasive procedure for treating symptomatic
fibroid disease. Increasing numbers of women report satisfaction
with the effectiveness and efficiency of the procedure over the
conventional options. The purpose of this article is to review
the literature regarding UAE and its development, techniques,
indications, results, and complications. The results to date
indicate that UAE is a highly successful, uterine-sparing
alternative to hysterectomy for women with symptomatic fibroid
A MEDLINE literature search using the words "uterine fibroid
embolization" (UFE) or "uterine artery embolization" (UAE) revealed
196 articles as of May 1, 2002. Those articles include review
articles, case series, case reports of adverse effects, and
technical notes; addressing anatomical vascular considerations,
fertility and pregnancy issues, animal experiments, embolic
material choices, quality of life, and cost effectiveness.
Many women with fibroids choose to seek treatment only for
symptomatic relief, with the main motivation often being
quality-of-life issues. Conservative measures and traditional
treatments may not be an option for many women. Surgical
interventions are an undesirable option for some women since many
consider the uterus an important aspect of their femininity.
The absence of an effective complication-free treatment for fibroid
disease has led to a plethora of treatment modalities. Uterine
artery embolization is a relatively new procedure that produces
impressive results in the treatment of symptomatic uterine
fibroids. It carries a very low rate of complications and preserves
Short history of UAE
Transarterial embolization for active pelvic bleeding has been
considered the therapy of choice for decades. Trauma surgeons have
long used pelvic embolization to control acute traumatic pelvic
hemorrhage. The first reported case of pelvic embolization for the
treatment of obstetrical hemorrhage was in 1979.
Since then, embolization has gained more recognition and has been
used to treat a wide variety of obstetric and gynecologic diseases
associated with bleeding, including postpartum hemorrhage and
Uterine artery embolization has also been used successfully as
presurgical gynecologic prophylaxis to decrease the amount of blood
loss. In 1994, Ravina et al
were the first to describe pelvic embolization or UAE as an adjunct
to surgery in the treatment of fibroids. A year later, he described
the procedure as the primary treatment of uterine fibroids.
Since 1994, there has been an exponential rise in the number of
UAEs performed annually. Worldwide, approximately 15,000 women,
including more than 10,000 in the United States, have been treated
with UAE for symptomatic uterine fibroid disease. Numerous
published reports involving a total of more than 2000 patients have
demonstrated the effectiveness and safety of this procedure.
Symptomatic uterine leiomyoma are a significant source of morbidity
to many women and place a substantial burden on our healthcare
system. Uterine artery embolization has emerged as a minimally
invasive procedure for treatment of symptomatic uterine fibroids
and has gained acceptance as a primary treatment for symptomatic
Pathophysiology of fibroids
Uterine fibroids are the most common benign tumors in women with
an estimated incidence of 20% to 40% in women over 35 years of age.
Fibroid tumors affect women of all ages and races; however, there
is a higher incidence among African-American women.
Leiomyoma is a benign smooth-muscle tumor that most commonly
affects the body of the uterus but may also be found in the cervix,
broad ligament, and, rarely, the ovary. The precise etiology of
leiomyomas is unknown, although it is clear that the effects of
hormones are pivotal as they typically occur during the
reproductive period when hormonal influences are at their maximum.
Studies have shown that leiomyomas have abnormal gene expression
that maintains high levels of sensitivity to estrogen during the
estrogen-dominated proliferative phase of the menstrual cycle.
Fibroids may vary in size from a few millimeters to 20 cm in size
and may become symptomatic depending on their location and
Menorrhagia is the most common presenting symptom of fibroids.
The bleeding can be severe enough to cause microcytic anemia that
iron supplementation alone is not enough to correct. Submucosal
fibroids cause most bleeding in women with fibroids. Because of
their location on the endometrium, submucosal fibroids place
pressure on the uterine lining that builds with each menstrual
cycle. This, in turn, can cause abnormal bleeding.
Another common fibroid-related symptom is pelvic pain or pressure
and may even, depending on their location (ie, subserosal), affect
the gastrointestinal or genitourinary systems. Pelvic pressure from
the increasing size of a fibroid, regardless of location, can also
produce menorrhagia. Fibroids may transmit transmural pressure on
the bladder, causing urinary frequency. If large enough, fibroids
may obstruct urinary flow through pressure on the ureters.
Similarly, a fibroid may put pressure upon the bowel, causing
constipation, painful bowel movements, and hemorrhoids. Fibroids
may even cause neuropathic pain often involving the lower back and
legs. Frequent complaints from patients include increased abdominal
girth and distention, producing a disturbing cosmetic effect.
During pregnancy, fibroids can cause recurrent miscarriage and
Medical treatment for uterine fibroids may include the use of
nonsteroidal anti-inflammatory agents, oral contraceptive pills, or
progesterone analogs. Gonadotropin-releasing hormone agonist (GnRH)
is reserved for more severe cases and is mainly limited to
presurgical management to decrease blood loss during subsequent
myomectomy or hysterectomy.
This treatment may result in improvement of symptoms and reduction
in fibroid size of an average of 40% in the first 3 months of
GnRH is associated with postmenopausal symptomatology and cannot be
used for periods longer than 6 to 9 months.
The fibroids often regrow to their original size within a few
months of discontinuing the treatment.
Operative management of uterine fibroids includes laparoscopic,
hysteroscopic, vaginal, or abdominal hysterectomies. These
procedures may be associated with significant surgical morbidity
(adhesions, infection, blood loss, thromboembolic events) and
Fibroid disease is the single most common condition (30%), and
gynecologists in the United States perform more than 150,000
hysterectomies each year to relieve symptoms of uterine fibroids.
The rate of hysterectomy, however, has shown to vary with
geographic region, the woman's age, level of education, and
The main advantage of hysterectomy is that the risk of further
fibroids is nonexistent. It is, however, a major surgical procedure
with an extended recovery period of up to 6 weeks and with
significant postoperative morbidity and mortality. Any hysterectomy
means the end of childbearing, and in addition to the direct
surgical risks, there may be long-term physical, emotional, and
psychological effects, potentially including depression and loss of
If a salpingo-oophorectmy is performed along with the hysterectomy
prior to menopause, it triggers premature onset of menopause with
loss of ovarian-derived estrogen and androgens and may increase the
risk of early bone loss and the onset of menopausal symptoms.
Surgical alternatives to hysterectomy have evolved, resulting in
a 20% decline in the prevalence of the procedure in the last
quarter century. Each year 35,000 myomectomies (transvaginal or
laparoscopic) are performed to relieve the symptoms of uterine
fibroids. Laparoscopic myomectomies are limited to a maximum
fibroid size of 10 cm, or not more than four leiomyomas.
There is an average of 81% resolution of menorrhagia with
However, this procedure has its associated increased risk of
hemorrhage, adhesions, lengthy operating time, postoperative
morbidity (including pain), and longer hospital stays than with
In addition to these shortcomings, 20% to 25% of women who undergo
a myomectomy will ultimately require an additional procedure to
further treat the fibroid.
Two recent cost studies from a single institution found that UAE
compares favorably with hysterectomy
The estimated hospital cost for UAE was $3080. The cost for
hysterectomy ranged from $3100 to $4900, depending on the type of
procedure performed, and the cost for abdominal myomectomy was
$5597. Although not included in these studies, there is an indirect
cost of the lost work days during recovery, which is significantly
lower in patients receiving UAE than in those undergoing
hysterectomies or myomectomies.
Patient selection and preprocedure evaluation are extremely
important: the correct diagnosis of symptomatic fibroid disease
must be reached and other causes of uterine bleeding must be
excluded. The patient should be interviewed, and a consultation
with a gynecologist is advocated. In our institution, the patient
is given reading materials to further familiarize her with all
aspects of the treatment. Currently, premenopausal women who have
uterine fibroids and symptoms that correlate reasonably well with
the size and location of the fibroids are candidates for UAE. A
complete medical history should be obtained. A physical
examination, including a pelvic examination, should be performed
within 6 months of the procedure. A normal PAP smear within 12
months is also required. The possibility of pregnancy should be
excluded. If the patient has history of pelvic infection, cultures
for gonorrhea and chlamydia should be obtained. In our institution,
we obtain follicle-stimulating hormone (FSH) levels prior to UAE.
Endometrial biopsy may be obtained for patients with abnormal
bleeding, particularly if they are older than age 40.
If the patient is taking GnRH, the medication should be
discontinued 8 to 12 weeks prior to procedure.
Contraindications to UAE include pregnancy, acute or chronic
pelvic infection, arteriovenous malformation, renal insufficiency,
active vasculitis, or pelvic irradiation. Although severe allergy
to contrast is a contraindication to perform UAE, there is a case
report in the literature describing technical success using CO
The possibility of a leiomyosarcoma should always be considered
part of the differential diagnosis of uterine fibroids. It is
extremely difficult, however, to prospectively differentiate a
growing fibroid from a leiomyosarcoma with the currently employed
imaging modalities, including magnetic resonance imaging (MRI).
Theoretically, a positron-emission tomography (PET) scan might be
This lack of adequate imaging options has led many physicians to
perform deep fibroid biopsies, although this procedure has a low
reliability rate (specificity and sensitivity), even in cases with
known leiomyosarcoma. The incidence of leiomyosarcoma is rare and
routine biopsies are not advocated, particularly given the low
Postprocedure follow-up imaging is necessary; both ultrasound
and MRI are effective. The physician should be suspicious of
cancerous lesions if the fibroids do not decrease in size after
embolization or, particularly, if the fibroids continue to
Women with extremely large fibroids (>20 cm) may not
experience significant benefit from UAE due to bulk-related
symptoms. McLucas et al
identified, with a strong statistical significance (
= 0.05), that leiomyomata with a diameter >8.5 cm is a predictor
of failure. Although Spies et al
could not duplicate the statistical strength of McLucas's report,
their conclusion was that smaller size leiomyoma and submucosal
location were indicators for a positive outcome. There are no
strong data to suggest that large fibroids are at increased risk
for post-UAE infection.
The initial reports of UAE suggested a link between UAE failure
and the presence of adenomyosis.
These early studies, which were conducted retrospectively to find
an explanation for UAE failures, discovered islands of adenomyosis
on the pathological examination. In a more recent retrospective
series of 15 patients, the authors concluded that UAE can be
beneficial in patients with menorrhagia and adenomyosis.
We also recently reported our experience in patients with uterine
fibroids and co-existing adenomyosis.
Although the number of patients was small (10 patients), there was
a suggestion that women with focal adenomyosis may be more
responsive to UAE than those with diffuse adenomyosis.
Many interventional radiologists say they would consider
offering UAE to patients with adenomyosis, since the only other
successful alternative is hysterectomy, and would perform the
procedure after counseling the patient and explaining the potential
for failure (G. Siskin, informal oral communication, 2002 SCVIR
Menorrhagia in postmenopausal women can be severe enough that
some women may seek relief. In our experience, postmenopausal women
who refuse surgery and who are still suffering from fibroids can
experience relief following UAE. Careful gynecologic clearance must
be performed to exclude malignancy. This procedure can be very
challenging technically, particularly in patients not receiving
hormone replacement therapy.
The uterine artery is typically small and can be very difficult to
Prior to UAE, imaging should be performed to confirm the
presence of fibroids, to exclude other causes of bleeding, and to
serve as a baseline for future follow-up. Both ultrasound and MRI
are capable of diagnosing fibroids, showing their location, and
obtaining volumes to determine both fibroid and uterine size.
Although ultrasound is significantly less costly than MRI, there is
a trend toward obtaining an MRI rather than an ultrasound. An MRI
is less operator-dependent and is reproducible. It has been shown
to be more specific and sensitive than ultrasound for imaging of
It is better at defining pedunculated fibroids and concomitant
diseases, such as adenomyosis, which may affect management.
Patients with subserosal pedunculated fibroids have a theoretical
risk of devascularization of the attachment leading to torsion or
even detachment of the fibroid; in these cases, a necrotic mass
will be left in the peritoneal cavity.
Patients may benefit from laparoscopic myomectomy with or without
premyomectomy UAE to decrease intraoperative bleeding. Patients
with submucosal fibroids may benefit from hysteroscopic myomectomy
since there is a risk of degenerating fibroid falling into the
uterine cavity, a phenomenon noted even with nonpedunculated
There is a recent trend to perform perfusion MRI with
gadolinium. In one study, it was found that there is a difference
in perfusion between the myometrium and leiomyoma following
At 1 month, there was recovery of myometrial perfusion but
perfusion to the leiomyoma remained depressed. The reduction of
leiomyoma perfusion correlated with the improvement in clinical
score at 1 month. Leiomyomas high in signal intensity on the
initial T2-weighted images showed greater volume reduction than
those with low signal intensity. The authors concluded that dynamic
MRI may be used to predict clinical response, while signal
intensity on T2-weighted images predicts volume reduction.
Three-dimensional color Doppler sonography can depict fibroid
vascularity and, in some cases, can reveal collateral flow not
depicted by uterine artery (UA) arteriography
; however, post-UAE sonographic peak systolic velocity did not show
Infection control and pain management
On the day of the UAE, informed consent is obtained from the
patient. Preprocedure prophylactic antibiotic administration is
advocated. Most interventional radiologists use cefazoline (Ancef,
SmithKline Bechum, Pittsburg, PA), others may use antibiotic with
more gram-negative coverage such as ceftriaxone (Rocephin, Roche,
Nutley, NJ). A Foley catheter is inserted to eliminate impairment
of visualization of pelvic vasculature due to a distended
A protocol for pain management should be developed in
consultation with the anesthesia service. Different pain management
schemes have been developed, mostly dependent on each institution's
protocol. This protocol should include preprocedure,
intra-procedure, and immediate postprocedure management, as well as
in-hospital and outpatient pain management.
Most centers administer a combination of nonsteroidal
anti-inflammatory drugs and narcotics prior to initiation of the
procedure. Most UAE procedures are performed under conscious
sedation, achieved with an intravenous (IV) combination of
narcotics and benzodiazepines, typically fentanyl, morphine
sulphate, and midazolam. Subcutaneous 1% lidocaine solution is the
local anesthetic of choice. Unlike tumor embolization in other
organs, lidocaine injection into the UA has led to spasm and
constriction of the UA, resulting in incomplete embolization and no
significant pain relief.
There are several published strategies for pain management
following UAE. Oral, IV, or epidural pain medications have been
employed. Patient-controlled analgesia is frequently employed
post-UAE and the set-up must be in place as soon as the procedure
is over because frequently the pain may start immediately after UAE
or even near the end of the procedure.
Giving medications with different mechanisms of action, such as
nonsteroidal anti-inflammatory drugs and opioids, has proven to
provide adequate pain control in both the inpatient and outpatient
In most centers, patients will stay overnight for pain control;
however, some centers have had success performing the procedure in
an outpatient setting.
Almost all patients will experience postembolization syndrome,
consisting of a variable constellation of pelvic pain, cramping,
nausea, vomiting, fever, and lethargy. The pain may be most severe
immediately after the UAE. Although pain may indicate
devascularization of the fibroid or fibroid ischemia, pain has not
been found to be a reliable indicator of procedure success.
Lack of postprocedure pain, however, correlates well with procedure
failure. It is important to have a team approach and an agreed-upon
protocol among all services and individuals who may encounter the
patient during or after this procedure.
It should be kept in mind that UAE is a vascular procedure and
that careful attention to technique is essential for successful
results. For the most part, most interventionalists are well versed
in the different catheters and wires required to access the uterine
arteries and are fairly skilled at doing so. However, there are
certain issues that have been discussed in the literature that
Most interventional radiologists use the single-access, right
common femoral artery approach using a 5F sheath.
There are some who advocated using the double-access approach,
right and left common femoral arteries, citing the lower radiation
risk as well as shortened procedure time.
This approach has not been used widely; however, due to the need
for two interventional radiologists and the doubling of the risk of
access-siterelated complications. Moreover, there is a minor
additional cost of a selective catheter, and a significant increase
in cost if there is a need for two microcatheters.
Most interventional radiologists will place the tip of a 5F or
4F catheter at the aortic bifurcation and perform a pelvic
arteriogram to illustrate the origin of the internal iliac
arteries, confirm the presence of dilated uterine arteries, and
demonstrate the presence and location of a dominant UA. This step
may be substituted with a pelvic magnetic resonance arteriogram
Once in the internal iliac artery, most interventionalists use
an oblique posterior projection and perform a road map to assist in
selecting the UA. Typically, a contralateral oblique (20š to 30š)
is sufficient. Occasionally, a steep oblique (40š to 50š) is
needed, and infrequently, an ipsilateral oblique is required,
particularly in the case of upper origin of the UA from the main
trunk of the internal iliac artery.
For complete and successful embolization of the UA, the
interventional radiologist should be aware of the anatomical
variations of the artery. It is typically the first branch of the
anterior division of the internal iliac artery, and it may arise
from the medial or the lateral aspect of the anterior division.
Other variations of the origin of the UA relate to its take-off in
relation to the division of the internal iliac artery. Typically,
there is a shared origin with the cystic or vaginal arteries. The
UA has a tight curve in its proximal segment, followed by a
descending, transverse, and then ascending segment.
The cervicovaginal branches, which some believe play a role in
post-UAE sexual dysfunction,
typically originate from the transverse segment of the UA. If
possible, the tip of the catheter should be placed distal to those
branches. Arcuate (main intramural), radial, and peripheral uterine
arteries are further subdivisions of the UA that supply the body of
the uterus. In a hypervascular uterus "parasitized vascularity"
from ovarian or other pelvic vessels may occur.
In initial reports, UA catheterization was performed with a 4F
or 5F catheter; however, given that the UA is fairly tortuous
artery, introducing a 4Fr or 5Fr catheter may lead to straightening
the vessel, introduce artificial kinking, and reduce the flow
around the catheter. Multiple authors have described spasms and
constrictions preventing complete embolization with the use of such
catheters. There is a strong current trend toward use of a 3F
microcatheter to cannulate the UA. In a hand poll conducted at the
2002 Annual Meeting of the Society of Cardiovascular &
Interventional Radiology (SCVIR), close to 40% of interventional
radiologists said that they routinely used 3F microcatheters in
every case, as do we in our practice. Furthermore, nearly 100% of
those polled said they had used microcatheters at least in some
It should also be remembered that patients who are on GnRH
therapy might experience spasm and constriction of the UA, leading
to difficult and sometimes incomplete embolization.
There are important collaterals between the right and left UA,
between the ovarian artery and the UA, and between the round
ligament artery and the UA. In most cases, the fibroid receives its
blood supply from the UA alone. In some cases, the ovarian artery
may provide vascular supply to the fibroid. If reflux into the
ovarian artery is noted during embolization, most authors recommend
continuing the embolization as long as the embolic material is not
allowed to go beyond a short segment into the ovarian artery so
that it immediately washes back into the uterus.
The presence of ovarian collaterals to the fibroids is a
recognized risk for UAE failure.
It has been suggested that routine pre-embolization search
(aortography and selected ovarian arteriography) for ovarian supply
of fibroids is not warranted because of the assumed rarity of such
collateral supplies and the radiation dose to the patient.
Given the impact of the discovery of ovarian collaterals on patient
management, there is a current trend--including in our practice--to
perform aortography at the conclusion of the embolization, with the
tip of the catheter at the level of the renal arteries in search
for ovarian collaterals.
If dilated ovarian arteries are discovered, the option of distal
particulate embolization or proximal embolization with a temporary
agent should be considered.
If no intervention was made, the mere recognition of a major
ovarian collateral may expedite the surgical treatment or bring the
patient back for a second procedure with the intent to embolize the
ovarian artery. Although not reported in the literature, an
abdominal/pelvic MRA may be useful in discovering dilated ovarian
The choice of embolic material should be based on the size of
the vessels. The blood supply of uterine leiomyoma is provided by
the uterine arteries and is characterized by two vascular networks
of different sizes. The peripheral blood supply comes from dilated
and tortuous arteries, and the central blood supply is composed of
few fine arterioles derived from the peripheral network.
According to research by Pelage et al,
the target vessels for UAE are the prefibroid vascular plexuses,
which are typically 500 to 600 µm in diameter.
There are currently three embolic materials on the market that
are used in UAE
: gelatin sponge pledgets (Gelfoam, Pharmacia & Upjohn Co.,
Kalamazoo, MI), polyvinyl alcohol particles (PVA) (Contour,
Interventional Therapeutic, Fermont, CA), and tri-acryl gelatin
microspheres (Embospheres, BioSphere Medical, Rockland, MA).
Although each agent has advantages and disadvantages, there is no
consensus at this time as to which embolic material is best. Thus,
the choice of embolic material is an individual choice for the
Gelfoam is significantly less expensive than any other embolic
material. In the past, it was used as the embolic material of
choice for obstetrical hemorrhage since it preserved fertility in
It may be used in UAE for fibroid disease as a sole embolic
or it can be used to supplement the embolization or to "cap" a
vessel that has been embolized with a different agent.
The majority of UAE procedures reported in the literature have
been performed with PVA as the embolic agent. The recommended size
is 300 to 500 µm or 500 to 700 µm.
There are disadvantages, however, to using PVA. It tends to occlude
catheters, particularly the 3F size. It also tends to aggregate in
and lodge in proximal vessels that are larger than those vessels
believed ideal for UAE.
Calibrated microspheres have been introduced into the market
They are appealing because, unlike PVA, they are less likely to
occlude a microcatheter and they are deformable. Their homogenous
flow-dependent distribution makes them well suited for occluding
the target vessels thought to be ideal for embolization.
Recommended sizes are 500 to 700 µm or 700 to 900 µm depending on
the use of microcatheters.
In a late-breaking abstract at the 2002 Annual SCVIR meeting, the
authors compared the new generation of Embospheres, EmboGold, with
the bland Embospheres and found a surprisingly high rate (44% or 4
of 9 patients) of endometritis with the EmboGold.
We have used EmboGold in more than 20 patients, and our
endometritis rate for both bland Embospheres and EmboGold is
Although Gelfoam is considered a temporary agent because it is
reabsorbed relatively rapidly, it stimulates the most inflammatory
response of the embolic agents used.
In women who undergo UAE with PVA alone, there appears to be
restoration of flow in the main UA within 16 months after UAE.
Sterling et al
found that by using both PVA and Gelfoam together, the vessels
remain occluded 3 to 12 months postprocedure. They do not, however,
advocate the use of this method for patients desiring
Recent presentations at the SCVIR meeting described
extravascular location of Embospheres on pathologic examination of
hepatic tumors resected postembolization.
The size of embo-spheres used in hepatic tumor embol-ization is
significantly smaller (40 to 120 µm) than those used in UAE, and it
remains to be seen if larger particles behave in the same manner as
the smaller particles.
The end point
The initial goal of UAE using PVA was to maintain embolization
until there was complete stasis in the UA. This approach is being
abandoned by most interventional radiologists who now look for
other signs to end the embolization. This has become more important
since Embospheres do not accomplish the complete stasis seen with
PVA. Most interventional radiologists now look for signs such as
the "pruned-tree" appearance of the ascending segment of the UA
(Figure 1), or the appearance of new collaterals or filling of
previously undemonstrated ovarian artery. Other signs include
staining of the lower uterine segment and reflux of contrast around
the catheter in the UA.
More recently fluoroscopic visualization of 5 pulsations of
contrast in the UA before it dissipates has been used as another
sign to end the embolization (J. Spies, informal oral
communication, SCVIR 2002 Annual Meeting).
There are currently more than 20 large (>50) case series
published worldwide. Table 1 summarizes the results of 11 of them.
The reported technical success rate of bilateral UAE is between 95%
and 100%, and may approach 100% in cases in which the risk of
dissecting the UA would be significantly reduced with the use of a
3F microcatheter. Symptomatic relief of menorrhagia is between 85%
and 96%, and relief from bulk symptoms is between 69% and 92%.
There is a 30% to 50% decrease in uterus size and 40% to 100%
decrease in fibroid size. Most patients (90% to 100%) had a 1-night
Pathologically, fibroids undergo hyaline degeneration following
UAE. Grossly, they are soft in consistency and pale on pathologic
sectioning. The hyalinized areas are translucent and may be either
small and localized or extensive. Microscopically, typical hyaline
changes are characterized by marked cellularity and loss of the
usual myomatous architecture.
After UAE, the majority of leiomyomata will decrease in volume and
show changes on MRI, characterized by an increased signal intensity
on T1-weighted images and a homogenous decreased signal intensity
on T2-weighted images (Figure 2).
Fibroids may have a hypoechoic appearance on sonography, which
correlates well with the hyaline degeneration seen in fibroids
Unlike the typical dense, coarse, and central calcification of
spontaneously degenerating fibroids, fibroids degenerating post-UAE
have peripheral calcification that correlates with the peripheral
aggregation of PVA particles in peripheral fibroid arteries.
There is an average failure rate for UAE of approximately 10%.
Suspected causes include incomplete or unilateral embolization,
extremely large fibroids, presence of uterine leiomyosarcoma,
coexisting adenomyosis, and presence of collateral blood supply,
such as ovarian artery and round ligament artery (a branch of the
inferior epigastric artery).
In some cases, incomplete embol-ization is due to spasm or
constriction of the UA. This can be due to the use of 4F or 5F
catheters and has also been associated with theuse of GnRh. Many
interventional radiologists now use 3Fr microcatheters routinely to
select and embolize the UA. In a recent study, 8 of 12 patients who
underwent unilateral UAE had unsuccessful outcomes due to technical
One failure was in a patient with a previously ligated internal
iliac artery and another was in a patient who had unilateral UAE
for technical reasons and did not undergo a second UAE. The authors
concluded that patients who undergo unilateral UAE for technical
reasons (inability to access the UA, eg, spasm) should be offered a
second UAE to embolize the failed site shortly (within 3 to 4
weeks) after the initial procedure. Patients with congenitally
absent UA may respond with similar success to those who undergo
Fertility, pregnancy, and sexuality
Leiomyomas are a well-known cause of infertility, and there are
serious risks in pregnancy in a leiomatous uterus. The effect of
UAE on fertility is not clear for several reasons. To date, most
treated patients are in their 40s and 50s and do not desire future
pregnancies. However, numerous pregnancies have been reported after
These positive reports are difficult to interpret since the exact
number of women attempting to get pregnant is not available. In a
series of 12 patients with obstetric hemorrhage who underwent
Gelfoam embolization, 11 resumed normal menses and all 3 patients
who desired pregnancy achieved full-term, healthy newborns.
Currently, most interventional radiologists, for ethical reasons,
counsel women desiring future pregnancy to consider other options.
McLucas et al
reported a 33% term pregnancy rate in women younger than 40 years
old, a rate comparable to that of women who underwent myomectomy.
The authors conclude that pregnancy is a viable option for women
undergoing UAE and that their preliminary data suggest that
fertility is enhanced in women undergoing UAE.
A UAE experiment was performed in sheep with no fibroids and was
found to be associated with a decrease in the number of
We wonder if it would not be the case in uteri with fibroids, but
unfortunately there are no animal models with fibroids. Additional
studies are needed to further evaluate the effect of UAE on
fertility in leiomyomatous uteri.
The effect of UAE on menses is also difficult to assess for the
same reasons. Most series report a rate of 2% to 5% cessation of
In a recent series of 66 women, the reported ovarian failure rate
; however, when the authors stratified their data, it was noted
that no women under 45 years of age developed ovarian failure.
Moreover, surgical options do not appear to be protective from
early hormonal menopause even in women undergoing
In one study, there was no statistically significant change (
= 0.16) in ovarian function measured by basal FSH after UAE for the
However, for patients aged 45 or older, there was approximately a
15% chance of an increase in basal FSH into the perimenopausal
Impaired sexual function after hysterectomy is well documented
in the literature.
There are also substantial, well-described emotional and
psychological problems that may occur in a woman after
A woman may feel "desexed," or may consider herself "half a woman."
There is a single case report in the literature describing sexual
dysfunction after UAE.
The authors propose that occlusion of the cervicovaginal branches
may have caused cervical ischemia and, in turn, loss of orgasm;
however, the patient eventually recovered sexual function. Recent
abstracts reported that UAE was found not to cause sexual
dysfunction and may even improve sexual function in patients
presenting with bulk symptoms.
Arteriographic complications (such as hematoma, bleeding, and
puncture-site arterial thrombosis) and complications related to the
use of closure devices
have been reported. Most complications are minor, rarely requiring
aggressive thrombolytic therapy. One case, however, did require a
There are also reports of uterine infections, most minor, but a few
required hysterectomies, and one case resulted in fatal septicemia.
There are reports of uterine ischemia and perforation. There have
been cases of deep vein thrombosis and two reported cases of
pulmonary embolism, one resulting in death.
There are a total of four known cases of death following UAE, the
other two deaths being from sepsis.
Radiation exposure during UAE is of particular concern and
deserves special attention. In a 20-patient series published by
Nikolic et al,
the mean estimated ovarian dose was 22.34 cGy. This dose is
equivalent to one to three barium enema examinations, and is
unlikely to result in acute or long-term radiation injury or
genetic risk to the patient. However, the dose range reported in
the same series was 4 to 65 cGY.
It is important to note this variation in radiation dose, which was
attributed to inconsistent fluoroscopic times. With more
experience, the same group of physicians was able to decrease the
radiation exposure by approximately 50% using pulsed fluoroscopy,
avoiding magnification and oblique fluoroscopy, and by simultaneous
bilateral embolization and arteriography.
Uterine artery embolization is a very promising and minimally
invasive procedure with extremely favorable results. SCVIR (which
recently changed its name to the Society of Interventional
Radiology) has a comprehensive research strategy to validate UAE as
a primary treatment for symptomatic uterine fibroids and has
created the UFE registry. The interventional community as a whole
is committed to research and information gathering so that patients
may benefit from a state-of-the-art procedure that provides better
care with fewer adverse effects.