Endometriosis, defined as the presence of endometrium-like
tissue outside the uterus, affects approximately 10% of women
of reproductive age [1, 2]. The origin of ectopic endometrium
remains unresolved: some gynecologists believe that it originates
from endometrial tissue in the backflow of menstrual bleeding,
whereas others believe that it is a result of coelomic metaplasia
[1]. These discrepancies yield continuous debates among gyne-
cologists. Endometriosis affects many organs and structures,
including the ovary, fallopian tube, pelvic serosa, rectum, retro-
peritoneal structures (e.g., the ureter), and more remote organs,
including the lungs. The most frequently affected organ is the
ovary. Ovarian endometriosis typically presents as an ovarian
cyst containing old blood; usually called achocolate cystor an
endometriotic cyst, these are diagnosed in about 17% to 44% of
women with endometriosis [2].
Although the diagnosis of endometriosis is sometimes dif-
ficult, especially during early-stage disease, the characteristic
appearance of a typical ovarian endometriotic cyst can be
easily detected with MRI. After a diagnosis of ovarian endo-
metriotic cyst, there are several management options, including
careful follow-up, medication, and surgical intervention. The
efficacy of these options is different according to the purpose
of the treatment; for instance, medication is more effective for
relieving pain than for recovering fertility.
Endometriosis causes three major clinical disruptions: pain,
infertility, and malignant transformation. The most common
symptom in younger patients is endometriosis-associated pain
including dysmenorrhea, which, if mistreated, may lead to
endometriosis-associated infertility. Endometriosis-associated
ovarian cancer has been recognized recently. It generally
affects elderly women, especially postmenopausal women
who are symptom-free and have no childbearing plans. Be-
cause the symptoms and problems in patients with endometri-
osis vary according to the woman ’s age, the severity of the
disease, and individual social requirements, the aim of treat-
ment should be specific to each patient (Fig.1). In this review,
we summarize the updated management of endometriotic cyst
in several clinical situations.
M. Mandai ( *) : A. Suzuki : N. Matsumura : T. Baba :
K. Y amaguchi: J. Hamanishi : Y . Y oshioka: K. Kosaka :
I. Konishi
Department of Gynecology and Obstetrics,
Kyoto University Graduate School of Medicine,
54 Shogoin Kawahara-cho, Sakyo-ku,
Kyoto 606-8507, Japan
e-mail:
[email protected]
Curr Obstet Gynecol Rep (2012) 1:16 –24
DOI 10.1007/s13669-011-0002-3
Diagnosis of Endometriotic Cyst
The most useful diagnostic imaging modalities for endo-
metriotic cyst are ultrasonography (US) and MRI.
Exploratory Examination
Although plentiful information can be obtained from imag-
ing analyses, the importanc e of a physical examination,
especially an internal examination, should not be over-
looked. With the aid of transvaginal US, careful internal
examination by the experienced physician can identify the
site causing pelvic pain and estimate the presence or absence
of adhesions. Posttherapeutic improvement in pelvic tender-
ness detected by examination is as informative as improve-
ment detected by imaging analysis.
Ultrasonography
US is used mainly in outpatient clinics for the screening of
an adnexal mass, following exploratory examination. Typi-
cally, an ovarian endometriotic cyst presents with a diffuse,
low-echoic appearance with occasional hyperechoic foci in
the wall of unilocular or multilocular cysts 3 to 6 cm in
diameter [ 3, 4] (Fig. 2).
Differential diagnosis includes a mature cystic teratoma
(or so-called dermoid cyst), which generally shows a more
echogenic internal structure with an acoustic shadow reflect-
ing hairballs and calcifications. Other differential diagnoses
include functional cysts, such as a lutein cyst or a hemor-
rhagic follicular cyst, a tubo-ovarian abscess, and ovarian
cancer [ 3]. Usually, differentiating an endometriotic cyst
from other ovarian cysts is not difficult, using a precise
evaluation of structural features and careful short-term
follow-up. However, it is occasionally difficult to exclude
other possibilities, especially when the cyst contains a solid
portion or shows a wall irregularity. This finding most often
represents a hemorrhagic clot, but it is difficult to exclude
malignancy (Fig. 3). Color Doppler US may be useful for
the differential diagnosis, but its effectiveness remains un-
certain [ 5]. In such cases, further examination with MRI
should be considered [ 3].
Because it is neither invasive nor expensive, US is also
useful in the follow-up of endometriotic cyst. Regular
check-ups every 6 months should be recommended. If any
alteration in the US appearance is noticed, a closer follow-up
or additional MRI examination is necessary.
Magnetic Resonance Imaging
MRI is one of the most powerful and informative diagnostic
tools for an endometriotic cyst. Typically, an endometriotic
cyst shows high intensity in both T1-weighted and T2-
weighted images, reflecting the blood element in the cyst [ 3,
6] (Fig. 2). A “shading” or “shading sign ” refers to a T2
shortening in the cyst, corresponding to a hyperintense portion
on the T1 image, which is useful to distinguish endometriotic
cyst from other blood-containing lesions, such as a hemor-
rhagic corpus luteum cyst [ 3, 4]. Although the hypointensity
typically presents either as a focal/diffuse area or a layering
with a hypointense fluid level, a significant proportion of
cases show only a complete loss of signal intensity [ 7]. Lack
of fat suppression helps to distinguish an endometriotic cyst
from a dermoid cyst [4]. In cases of endometriotic cyst with a
Infertility
Pain
(Menopause) Elder ageYounger age Reproductive age
Medical care
Curative (radical) treatmentPreservation of ovarian function
Malignant transformation
Surgical intervention
Fig. 1 The symptoms and problems in patients with endometriosis vary according to the age of the patient, the severity of the disease, and
individual social requirements. Therefore, the aim of treatment should be specific to each patient
Curr Obstet Gynecol Rep (2012) 1:16 –24 17
solid portion, contrast enhancement is mandatory to exclude
malignancy, such as a clear cell carcinoma [ 3, 8].
Malignant transformation of endometriotic cyst is the most
serious problem related to late-stage endometriosis. If US
screening shows atypical findings such as a nodular portion,
wall thickening, or a significant change in appearance during
follow-up, MRI is helpful not only to rule out malignancies
but also to estimate the histologic subtype of malignancies
(Fig. 3). For this purpose, various parameters should be taken
into account, such as maximum diameter, the presence of
shading, and the size and the nature of the nodular portion.
The most apparent risk factor is enhancement of the nodular
portion, although a benign endometriotic cyst occasionally
harbors an enhanced nodule. According to a study by Tanaka
et al. [ 9], the diameter of the cyst nodule is significantly
correlated with a malignant phenotype. Lack of shading is
also an important finding in the malignant transformation of
endometriosis, especially when MRI scans are repeated in the
same patient. Tanaka et al. [ 9] reported that 81% of benign
endometriotic cysts showed shading on T2-weighted images,
but only 33% of malignant tumors showed shading. It is most
likely that a nonhemorrhagic secretion by malignant cells may
dilute the cyst’s contents, causing the loss of shading. One of
the difficulties in diagnosing malignancy in endometriosis is a
decidualized endometriosis during pregnancy, which presents
as a rapidly growing nodular portion or wall thickening with
abundant vascularity in the endometriotic cyst. This finding
can be easily misdiagnosed as a malignancy [ 10–12]. In such
cases, expectant management with careful serial follow-up is
needed. MRI is also useful to estimate histologic subtypes of
cancer arising in endometriosis. In cases of endometrioid
cancer, MRI shows either a solid or cystic pattern without
shading [ 13]. The nodular portions in the cyst tend to be
multiple rather than single. In contrast, a clear cell carcinoma
tends to be more cystic and unilocular, with one or several
nodular portions [8].
One of the important roles of MRI in treating a patient
with an endometriotic cyst is the diagnosis of coexisting
extraovarian endometriosis, as it has similar symptoms, such
as pain and infertility. Diagnosing it is also helpful to ensure
adequate surgical intervention. Endometriotic lesions fre-
quently involve the surface of the peritoneum and ovary.
Fat-suppressed images are useful to identify the lesion, but a
diagnosis is relatively difficult, resulting in poor diagnostic
accuracy [ 5]. The characteristic MRI pattern of superficial
endometriosis is either high T1 intensity with low T2 inten-
sity or high intensity in both T1 and T2 imaging. Deep
endometriosis, sometimes referred to as posterior endome-
triosis, often affects retroperitoneal organs, including the
ureter and rectum. It frequently causes severe pelvic pain
as a result of the involvement of the uterosacral ligament.
The sensitivity of diagnosis of deep endometriosis by MRI
is reported to be 76% to 86% [ 3]. Adhesions caused by
endometriosis are also important as a cause of infertility and
frequently make operation difficult. Using MRI, adhesions
are typically identified by low-signal-intensity strands.
Fig. 2 Typical images of an endometriotic cyst.a Ultrasonography (US), showing a unilocular cyst with a diffuse and low-level echo within it.b–d On
MRI scans, the contents of the cyst show high intensity in both T1-weighted and T2-weighted images, reflecting the blood element
18 Curr Obstet Gynecol Rep (2012) 1:16 –24
Management of Endometriotic Cyst According
to the Symptoms
The treatment options for ovarian endometriotic cyst are
either medical or surgical interventions. Observation is an-
other choice in some situations. Medical therapy typically
consists of androgens, progestogens, oral contraceptives
(OCs), and gonadotropin-releasing hormone (GnRH) ago-
nists. Surgical treatment for ovarian endometriotic cyst
varies from hysterectomy with salpingo-oophorectomy
(SO) to unilateral cystectomy with or without laparoscopy.
Treatment recommendations differ according to the purpose
of treatment and the symptoms of the patient.
Treatment of Endometriosis-Associated Pain
Although ovarian endometriotic cyst could be a cause of
pelvic pain, it is rare that endometriotic cyst is the only
cause of severe, chronic pain. Rather, accompanying extra-
ovarian endometriosis or resulting adhesions or inflamma-
tion may be responsible [ 14]. V arious drugs have been used
to treat endometriosis-associated pain. A GnRH agonist is
the most popular treatment choice, and a number of placebo-
controlled randomized studies have shown that these are
effective [ 15]. Other drugs, such as danazol, OCs, and
gestrinone have also been shown to be effective, with little
difference from GnRH agonists [ 15, 16, 17]. Dienogest, a
selective progestin, was also as effective as GnRH agonists
[18]. There are few published data, however, that indicate
whether medical treatment e ffectively alleviates pain in
women with symptomatic endometriotic cyst. Rana et al.
reported that a GnRH agonist or danazol is effective in
reducing the size of an endometriotic cyst and in controlling
pelvic pain and dysmenorrhea [ 19].
Surgery is thought to be the first line of treatment for pain
in women with endometriotic cyst [15]. Surgical treatment to
conserve bilateral ovaries includes drainage, sclerotherapy,
diathermy, laser vaporization, and cystectomy [20–22]. Drain-
age guided by laparoscopy or transvaginal US has reportedly
resulted in a high recurrence rate and is less effective for
relieving symptoms [ 20]. In addition, it can cause pelvic
infection or adhesions [ 20, 22]. Combining sclerotherapy
using ethanol, tetracycline, and methotrexate with aspiration
may reduce the rate of recurrence, although it can cause severe
adhesions, which may affect future fertility [ 22, 23]. Ovarian
cystectomy is a more definite treatment for endometriotic cyst.
Although several studies found no difference among various
surgical procedures, including drainage, ablation, and cystec-
tomy, randomized trials indicated a lower cumulative postop-
erative rate of recurrence of dysmenorrhea, dyspareunia, and
Fig. 3 Images of a case of clear cell carcinoma, which arose in the
same patient as Fig. 2 after an interval of 6 years. a ultrasonography
(US), showing that the cyst contains a solid portion and the cyst is
larger than it was 6 years ago. b–e On MRI scans, the cyst is unilocular
and shows high intensity both in T2-weighted images ( b, c) and T1-
weighted images ( d, e) with several nodular portions. These nodular
portions show isointensity to high intensity in the T2-weighted image
and low intensity in the T1-weighted images. e These portions also
show positive contrast enhancement (CE)
Curr Obstet Gynecol Rep (2012) 1:16 –24 19
chronic pelvic pain in patients who underwent cystectomy
compared with those who underwent drainage alone [ 21,
22]. Another obvious advantage of cystectomy is that histo-
logic examination is available. Uterine nerve ablation (UNA)
was reported to be effective in relieving pain in earlier studies
[22], but in recent randomized controlled trials, its effective-
ness in alleviating symptoms has been controversial. Several
reports found no difference in symptoms at 3 years after
surgery between the women who underwent laparoscopy
alone and the women who und erwent laparoscopy with
UNA [24, 25]. Several authors reported modest clinical bene-
fits of UNA [ 26, 27]. By contrast, many studies, including
randomized trials, showed that presacral neurectomy (PSN)
significantly improved symptoms [25, 27, 28], although some
patients suffered adverse effects from the procedure, including
constipation, bladder dysfunction, or intraoperative hemor-
rhage. Radical treatment options for women who do not
require fertility include oophorectomy and hysterectomy with
oophorectomy.
There are conflicting data on the role of postoperative
medical treatment. Randomized studies in which a GnRH
agonist or danazol was used postoperatively for 3 months
did not show a difference in the recurrence of pain compared
with a nontreated group [29, 30]. In contrast, treatment with a
GnRH agonist, danazol, or medroxyprogesterone acetate
(MPA) for 6 months after operation showed a significant
advantage against the recurrence of pain in randomized con-
trolled trials [ 31, 32]. These data suggest that postoperative
medical treatment should be administered for at least 6 months
and that treatment over a shorter period may not be beneficial
[22].
Treatment of Endometriosis-Associated Infertility
Because endometriosis is primarily a disease encountered in
women of reproductive age, infertility is one of its most im-
portant complications. The causal link between endometriosis
and infertility is not clearly defined [ 33]. It is generally be-
lieved that endometriosis impairs fertility in multiple ways [33,
34]. First, severe pelvic pain may interfere with regular sexual
intercourse in couples who are trying to conceive. Second,
endometriosis destroys the pelvic anatomy as it progresses,
thereby disrupting the normal fertilization procedure. The most
direct cause of infertility associated with endometriosis is tubal
obstruction. Closure of the cul-de-sac, adhesions, and disloca-
tion of the ovary or fallopian tube also interfere with natural
conception. Third, in addition to these mechanical impair-
ments, endometriosis affects fertility chemically and biologi-
cally. Inflammation caused by endometriosis alters the pelvic
environment, with increases in inflammatory cytokines,
growth factors, and angiogenic factors, which significantly
disrupt fertility [34]. For example, interleukins directly affect
sperm motility, and tumor necrosis factor (TNF)- α causes
DNA damage to the sperm [35–37]. These factors, along with
reactive oxygen species (ROS) produced by endometriosis,
also impede sperm capacitation, oocyte-sperm interaction,
and oocyte quality [33, 34].
Whether the presence of ovarian endometriotic cyst affects
the normal ovarian function in terms of conception is unclear.
It is suggested that endometriosis does not affect the quality of
oocytes retained in the ovary. Rather, surgical intervention in
the endometriotic cyst may damage ovarian function to some
extent. In this view, which surgical procedure is favorable for
reproductive ability is a matter of concern [ 38].
Treatment for endometriosis-associated infertility consists
of
medical and surgical approaches, just as for pain. However,
because the purpose of treatment is different, the treatment
strategy differs. The type of treatment may also be different for
patients desiring natural conception and for those undergoing
assisted reproductive technology (ART). Almost all medical
treatments for endometriosis are based on the hormonal block-
age of ovarian function and are thus contraceptive; therefore,
medical treatment is usually not the chosen treatment for
women pursuing spontaneous conception [ 34]. Evidence
suggests that there is no improvement in pregnancy rates with
medical intervention for endometriosis [39].
Although removal of an ovarian endometriotic cyst is con-
sidered to be effective in correcting disrupted pelvic anatomy, it
is still undetermined whether surgical intervention for endome-
triosis, especially endometriotic cyst, contributes to natural
conception [ 34]. The presence of endometriotic cyst may
affect spontaneous ovulation [40]. Surgery for various degrees
of endometriosis appears to improve the rate of natural con-
ception, but determining the optimal operative procedure for
endometriotic cyst is another issue. Several reports, including
randomized controlled trials, indicate that ovarian cystectomy
by way of laparoscopy is superior to drainage or vaporization in
terms of higher pregnancy rates and lower recurrence rates [21,
41]. Yazbeck et al. [ 23] suggested that ethanol sclerotherapy
may offer a better result because it causes less damage to the
remaining ovarian function.
For patients who plan to undergo in vitro fertilization (IVF)
after treatment for infertility associated with endometriosis, the
management policy is different. It is estimated that 10–25% of
patients undergoing IVF have accompanying endometriosis,
and 17 –44% of them have endometriotic cyst [38 , 41]. The
presence of endometriosis and its severity may negatively
impact the outcomes of IVF, though the relationship is not
definitively proven [42]. Medical treatment for endometriotic
cyst prior to IVF reduces the size of the cyst, and several
randomized controlled trials indicate that GnRH agonist treat-
ment before IVF in women with endometriosis significantly
increases pregnancy rates [43, 44].
As regards surgical intervention, Tsoumpou et al. [ 41]
performed a meta-analysis of five studies comparing surgical
treatment versus no treatment for ovarian endometriotic cyst.
20 Curr Obstet Gynecol Rep (2012) 1:16 –24
The results showed no significant effect of treatment on IVF
pregnancy rates and on ovarian response to stimulation, com-
pared with no treatment. Nevertheless, the author mentioned
that the decision regarding surgery for endometriotic cyst in
asymptomatic women before IVF should take into account the
anticipated difficulty in accessing the follicles and the risk of
pelvic infection if inadvertent drainage of a large endometri-
otic cyst occurs at the time of retrieval. Expectant manage-
ment of endometriotic cyst before IVF presents risks that
include difficulty in monitoring follicular growth and sponta-
neous rupture and leakage, which may cause pelvic inflam-
mation, infection, and adhesion. On the other hand, surgery
may cause quantitative damage to ovarian reserves, as a
decrease in the number of eggs has been observed after
ovarian cystectomies, although the fertilization rates and the
quality of the embryos did not differ [ 22].
Management of Endometriosis in Terms of Development
of Ovarian Cancer
It is clinically evident that endometriosis gives rise to ovarian
cancer with a relatively high frequency, and it has been shown
that women with endometriosis have a higher risk of ovarian
cancer. According to a survey in Japan, approximately 1% of
cases of ovarian endometriosis transform into ovarian cancer
[45]. Importantly, this rate significantly increases in elderly
women. The risk of ovarian cancer in patients with endome-
triosis is reported to be significantly higher than in the general
population (standardized incidence ratio [SIR], 1.4–1.9), and
this risk increases in women with a longer history of endome-
triosis (SIR, 2.2–4.3) [46]. It is also well known that ovarian
cancers arising from endometriosis have a unique histology:
most are of a clear cell or endometrioid subtype, relatively rare
for ovarian cancer [47].
Numerous pathologic and molecular biologic data suggest
that endometriotic epithelium is actually a precursor of ovar-
ian cancer [ 47]. Continuation from morphologically benign
endometriosis to cancer is frequently observed, and occasion-
ally an intermediate lesion, such as atypical endometriosis, is
found nearby [48]. The analysis of the loss of heterozygosity
(LOH) and genetic mutations also indicates that endometriosis
shares common genetic events with associated ovarian cancer
[49]. These findings clearly show that ovarian cancer indeed
develops from endometriosis, and that both conditions have
common molecular pathways in their development. However,
the precise mechanism involved in the development of cancer
in endometriosis is still unclear. V arious genetic events are
implicated, as is the effect of the microenvironment, such as
endometriotic fluid containing highly concentrated iron [ 50,
51].
Considering these facts, it is important to take the risk of
cancer into account in managing endometriosis, especially in
elderly women. There are few guidelines, however, on how to
manage endometriosis as a precursor of ovarian cancer. This
lack is partly because the risk factors for ovarian cancer among
women with endometriosis are not fully defined. Especially in
the case of endometrioid adenocarcinoma, and possibly in
some cases of clear cell and mixed-type carcinomas, estrogen
plays an important role not only in the growth and maintenance
of endometriosis, a precursor lesion of these cancers, but also
in the development of cancer [ 47]. Mechanisms that may be
implicated in these conditions include unopposed estrogen
status, increased expression of estrogenα, progesterone resis-
tance, and increased aromatase activity, but these should be
further elucidated [46]. In terms of clinical relevance, several
authors reported that estrogen replacement therapy (ERT) in-
creased the risk of ovarian cancer, especially of the endome-
trioid subtype [52]. Although it has not been directly shown
that estrogen increases the risk of endometriosis-associated
cancer, this possibility should be considered when introducing
ERT in women who have a history of endometriosis, even after
menopause [ 52]. There are several reports of endometrioid
adenocarcinoma in patients who underwent a hysterectomy
with bilateral oophorectomy for endometriosis with subse-
quent long-term estrogen use [ 53]. It is generally recommen-
ded to add a progestin if ERT is necessary after menopause or
after a hysterectomy with oophorectomy for endometriosis
[54].
Whether surgical intervention is indicated for cancer pre-
vention in women with endometriosis is an important issue but
is not clearly defined. It is unclear whether conservative sur-
gery, such as ovarian cystectomy or vaporization, reduces the
r
isk of malignant transformation of endometriosis [ 47]. As
previously mentioned, several surveys indicate that women
who have a longstanding history of endometriosis have a
greater risk of developing ovarian cancer [46], which suggests
that surgical intervention somehow may reduce the risk of
malignant transformation. Interestingly, women who under-
went a hysterectomy after a diagnosis of endometriosis did
not show an increased risk of ovarian cancer, thus indicating
that hysterectomy and possibly tubal ligation may have some
protective role [46]. For elderly women in whom endometri-
otic cyst has been diagnosed, early detection of cancer is
clinically important. It is generally accepted that an endometri-
otic cyst growing after menopause should be resected.
Kobayashi et al. [ 55] demonstrated that the risk factors for
malignant transformation of endometriotic cyst are older age,
postmenopausal status, and larger tumor size. They recom-
mended considering surgery in postmenopausal women with
an endometriotic cyst measuring 9 cm or larger.
It is still unclear whether medical treatment for endometri-
osis reduces the risk of developing ovarian cancer. Oral contra-
ceptives are known to reduce ovarian cancer risk partly by
inhibiting ovulation, which is thought to be a major risk for
ovarian cancer. Together with their therapeutic effect on endo-
metriosis, OCs may reduce the risk of malignant transformation
Curr Obstet Gynecol Rep (2012) 1:16 –24 21
of endometriosis, but there is not yet any conclusive study on
this issue. The use of a GnRH agonist may reduce or increase
the risk of endometriosis-associated ovarian cancer because
although postmenopausal status increases the risk of ovarian
cancer, GnRH agonists suppress e ndometriosis itself. Newer
drugs such as dienogest may be used more frequently for
endometriosis, but no data are yet available on their effect on
cancer prevention. Clinical studies are needed on the effect of
medical care in preventing the development of endometriosis-
associated cancer.
Minimally Invasive Surgery for Endometriotic Cyst
As mentioned above, various surgical procedures are used to
manage various symptoms derived from endometriosis. Re-
cently, minimally invasive surgery under laparoscopy is becom-
ing the standard modality for the treatment of endometriosis,
especially in conservative therapy.
Laparotomy V ersus Laparoscopy for Endometriosis
Whether laparotomy or laparoscopic surgery is superior as a
surgical management technique for endometriosis is an im-
portant issue. A number of reports, including controlled
trials, indicate that pregnancy rates, monthly fecundity, and
recurrence rates are comparable between laparotomy and
laparoscopy [ 56, 57]. On the other hand, blood loss, length
of hospitalization, and recovery time are usually decreased
after laparoscopy [ 57]. It is generally thought that laparos-
copy is technically difficult and has a greater risk of surgical
complications than laparotomy, but a meta-analysis of pro-
spective randomized trials showed that laparoscopy and
laparotomy exposed patients equally to complications [ 58].
Therefore, except in cases with special indications, laparo-
scopic surgery is the first choice among surgical procedures
for infertile woman with endometriotic cyst.
Laparotomy may be more applicable for women with
severe pelvic endometriosis if curative surgery is planned.
However, even in very radical operations, such as REHCR
(radical en bloc hysterectomy and colorectal resection), lapa-
roscopy is reported to be comparable or superior to laparoto-
my in terms of symptoms and improvement in quality of life
[59].
Excision V ersus Ablative Surgery for Ovarian
Endometriosis
As previously mentioned, surgical procedures, including lap-
aroscopic procedures, include salpingo-oophorectomy (with
or without hysterectomy), ovarian cystectomy, ablation, and
drainage. Randomized trials clearly show that laparoscopic
excision of the cyst wall of an endometriotic cyst is superior to
ablation in terms of reduced recurrence, relief of pain, and
pregnancy rates [ 60]. Damage caused by the removal of
normal ovarian tissue in an excisional procedure is usually
minimal, but Donnez et al. [ 61] have recommended using
laser vaporization for the portion close to the hilus.
Surgery for Recurrent Endometriotic Cyst
V ercellini et al. [62] reviewed the reports on the efficacy of
repeat surgery for recurrent endometriosis. Among 313 patients
who wanted to conceive after repeat surgery, 81 women be-
came pregnant, with no significant difference between laparot-
omy and laparoscopy. However, the pregnancy rate after repeat
surgery was significantly lower than the rate after primary
surgery.