Page 18 - Journal of WALS

Puneet K Kochhar, Pranay Ghosh

PATHOGENESIS AND THE reproductive function due to endometriosis, such as tubal
MECHANISM OF INFERTILITY damage and severe adnexal adhesions, might be irreversible.

Several factors are believed to be involved in the pathogenesis STAGING OF ENDOMETRIOSIS
of endometriosis. Retrograde menstruation remains the The American Fertility Society (AFS) proposed its revised
dominant theory for development of pelvic endometriosis. staging in 1996. This remains the most widely used
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Failure of immunological mechanisms, angiogenesis and classification. This classification considers the size, site and
production of antibodies against endometrial cells may also depth of the lesions. Point scores were given depending upon
have a role. Endometriotic lesions secrete several pro- severity. Four stages of the disease were suggested: Stage I
inflammatory molecules contributing to development of pain (minimal), stage II (mild), stage III (moderate) and stage IV
and infertility. 8-10 (severe).
The most common site of endometriosis is the ovary. Other The revised AFS score enables easy and clear communi-
common sites are peritoneum, ovarian fossa, uterosacral cation through standardized reporting, but has a number of
ligaments, uterovesical fold and Pouch of Douglas. It can present significant drawbacks: 20
as dysmenorrhea, dyspareunia, chronic pelvic pain, infertility, i. It does not help in comparison of different treatments
irregular heavy periods, cyclical rectal bleeding, tenesmus, ii. It is unable to predict disease progression, impact on future
cyclical hematuria, ureteric obstruction, cyclical pain and fertility and disease recurrence rate
swelling in the umbilicus or scars. iii. It is prone to observational variation which impairs
Although there is substantial evidence confirming an reproducibility
association between endometriosis and infertility, a causal iv. It is also a poor indicator of severity as it does not consider
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relationship has not yet been established. Nevertheless, the bowel adhesions or multifocal nodular disease.
fecundity rate of infertile patients with minimal or mild
endometriosis is not significantly lower than that of women ROLE OF SURGICAL MANAGEMENT
with unexplained infertility. 12,13 Endometriosis may thus play a Endometriosis can be treated medically or surgically by
determinant role in infertility in more advanced forms only. In a laparoscopy or laparotomy. Medical hormonal treatment has
series of 123 women with endometriosis-associated infertility no role in the treatment of endometriosis-associated infertility
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undergoing expectant management, Olive et al observed a in the absence of pain. This is because any hormonal treatment
pregnancy rate of 45% in patients with mild disease and 19.5% used to suppress endometriosis is contraceptive and does not
in those with moderate disease. No conception was achieved in improve pregnancy rates. In fact, postoperative hormone therapy
patients with severe lesions. in patients with endometriosis prevents pregnancy during what
Moderate-severe endometriosis is likely to result in infertility may be the optimal time for conception to occur following
because of adhesions disrupting the anatomical relationships surgery.
between fallopian tube and ovary. Severe dyspareunia The advantages of laparoscopic surgery are quicker
preventing regular sexual intercourse could also affect fertility. recovery, shorter hospital stay, effective treatment of ovarian
Distal occlusion of the fallopian tube may result in hydrosalpinx, endometriomata and relief of pain. It also improves fertility
without increasing the risk of multiple pregnancies associated
leading to a direct effect on embryos as well as an alteration in
uterine implantation. 15 with assisted conception treatment. The limitation of laparoscopy
is the intraoperative risk of injury to adjacent structures.
Other mechanisms by which endometriosis may contribute Appropriate surgical skill and availability of appropriate
to infertility include disorders of folliculogenesis or endocrine equipment is required. There is a 6.3% conversion rate to
abnormality, inflammatory or immunological abnormality and laparotomy associated with gynecological laparoscopy. 21
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increased miscarriage rate. The presence of endometriosis Otherwise laparotomy is indicated only in cases of severe
affects multiple aspects of the reproductive cycle, including endometriosis with extensive dense adhesions along with deeply
oocyte quality, embryogenesis, and receptivity of the infiltrating endometriosis.
endometrium. Further evidence of poor oocyte quality and Based on the results of a meta-analysis of cohort studies,
reduced implanting ability of embryos is provided by studies 15 years ago surgical treatment of endometriosis was estimated
showing no adverse effect on implantation rates in women with to produce overall crude pregnancy rates 38% higher than non-
endometriosis using donated oocytes. Recipients of oocytes surgical treatment. Moreover, surgical techniques have
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from donors with endometriosis have lower implantation evolved and instrumentation has improved tremendously.
rates. 16-18 More convincing evidence emerged from a randomized
Thus, even though laparoscopic surgery has become the clinical trial comparing diagnostic laparoscopy alone or resection
preferred treatment modality, it may not overcome the bio- or ablation of visible lesions that included 341 infertile patients
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molecular alterations associated with chronic inflammation and with minimal or mild endometriosis, in whom surgery enhanced
causing infertility. Furthermore, the anatomical insults to fertility.

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