EURURO Vol. 71 No. 5

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natural pregnancy rates in the subgroup of women who
were infertile at the time of the intervention (n = 27) were
not reported. Overall, albeit scarce, these results are in line
with the pregnancy rates of 42–44% observed after surgery
for deep endometriosis
On this basis, even if BE may actually be less detrimental
than deep endometriosis in general, one may reasonably
infer that concepts that are valid for the latter may also be
valid for the former.
Three main principles applying to infertility associated
with deep endometriosis in general deserve to be
outlined here. First, the benefits of surgery are modest. The
above-mentioned 42–44% rate of success after intervention
is probably an overestimation of the role of surgery because
some conceptions may occur regardless of surgery and
some published case series included both women who were
not infertile at the time of intervention and/or pregnancies
obtained with the use of in vitro fertilization . Overall,
one may postulate that only 20–25% of women may really
benefit from the intervention , a rate that is similar to
the pregnancy rate achieved with a single IVF cycle
. More generally, infertility may play a role in the
decision-making process on whether to operate women
with BE, but infertility alone as an indication for the
intervention is questionable. Pain symptoms and functional
disturbances should play the major role.
Second, IVF has to be considered the first-line option for
treating infertility. Compared to surgery, IVF appears to be
more effective and less risky . However, a possible
and peculiar concern here is the risk of IVF-mediated
progression of endometriosis. It cannot be excluded that
deep peritoneal lesions may progress under the influence of
the higher levels of peripheral sex steroids that typically
occur during ovarian hyperstimulation for IVF . It is
noteworthy that ureteral obstruction after IVF has been
reported in two cases A precise estimation of the
magnitude of this risk is lacking, but it is presumably
extremely rare, and thus is not sufficient to claim a
preventative role of surgery before IVF. Finally, some
authors claim that removal of deep lesions and BE may
increase the IVF success rate However, evidence
to support this approach is weak and the view lacks a
biological rationale.
Third, possible concerns regarding conservative manage-
ment of BE are the risk of endometriosis progression under
the influence of the pregnancy hormonal milieu and the
impact of the disease on difficulty in performing cesarean
sections in pregnant women. In fact, decidualization of
endometriosis may occur at any site, including the bladder
Lesions typically grow rapidly during the first weeks
of pregnancy and become highly vascularized, thus mim-
icking cancer. Five case reports of decidualized BE have been
reported in the literature . Decidualization of
BE may pose a diagnostic challenge, and surgery may
ultimately be decided to rule out cancer. Moreover,
decidualizationmay in some circumstances cause significant
progression of the lesions and possible demanding clinical
situations such as severe hemorrhage . However,
this situation is also extremely rare. A policy of systematic
surgery before pregnancy to prevent this complication is not
justified. However, clinicians should use extreme caution for
pregnant women with BE requiring a cesarean section who
were conservatively managed. The uterovesical pouch may
be partly or completely obliterated, preventing an easy and
safe transverse incision of the lower uterine segment to gain
access to the uterine cavity. Caudal reflection of the bladder
may become particularly challenging and may cause
significant bleeding. In such cases, obstetricians should
consider an alternative mode (longitudinally on the uterine
body) and/or site (transverse but more cranial than the
lower uterine segment) of incision to minimize the risk of
bladder injuries. Furthermore, it is advisable to plan delivery
for these patients in hospitals where urologists and blood
banks are promptly available.
3.5. Malignant transformation of BE
Only eight cases of tumor arising from foci of bladder
endometriosis have been reported so far in the English
literature . It should be considered that although
specific criteria have been established to define the
development of a malignant tumor from endometriosis
, not all the reports on this topic seemed to have
strictly followed these criteria. The age of the women
affected ranged from 35 to 62 yr, and only two had a
previous history of endometriosis. None of the cases was on
estrogen therapy at the time of tumor diagnosis. Pathologic
examination revealed two endometrioid and four clear-cell
carcinomas, while one was an endometrioid adenosarcoma.
Surgical treatment was generally offered.
Hence, current evidence does not support the removal of
bladder endometriotic lesions owing to the potential risk of
a malignant transformation because the phenomenon is
exceedingly rare, as documented in only a few case reports.
4. Conclusions
BE is rarely an isolated condition, and other forms of
endometriosis are frequently concomitant BE is a
challenging condition and the coexistence of other types of
endometriosis mean that clinical management of BE should
be undertaken at referral centers where collaboration
between a dedicated gynecologist and urologist is possible.
Women of reproductive age complaining of urinary
symptoms, most often during the menstrual cycle, should
always be investigated for the presence of BE. Urodynamics
has been investigated in the assessment of patients with BE.
However, scanty evidence is available and future research
should evaluate its clinical usefulness, in particular among
patients receiving medical/surgical treatment. Abdominal
ultrasonography and TVS should be regarded as first-line
techniques for assessment of BE owing to their accuracy,
safety, and cost-effectiveness. Once a diagnosis of BE has
been established, clinical management can be conserva-
tive—using hormonal therapies—or surgical. For patients
undergoing medical treatment, estrogen-progestogen com-
binations and progestogens should be preferred because of
their favorable safety, tolerability, and cost profiles that
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