Prevalence of Endometriosis and Peritoneal Pockets in Women with Infertility and/or Pelvic Pain

The severity and frequency distribution of endometriosis subtypes at different ages: a model to understand the natural history of endometriosis based on single centre/single surgeon data

Background and Objective

to study the natural history of endometriosis.

Materials and methods

the analysis of all women (n=2086) undergoing laparoscopy for pelvic pain and endometriosis between 1988 and 2011 at University Hospital Gasthuisberg.

Main outcome measures

the severity of subtle, typical, cystic and deep endometriosis in adult women, with or without a pregnancy, as estimated by their pelvic area and their volume.

Results

the number of women undergoing a laparoscopy increased up to 28 years of age and decreased thereafter. Between 24 and 44 years, the severity and relative frequencies of subtle, typical, cystic and deep lesions did not vary significantly. The number of women younger than 20 years was too small to ascertain the impression of less severe lesions. The severity of endometriosis lesions was not less in women with 1 or more previous pregnancies or with previous surgery. There was no bias over time since the type and severity of endometriosis lesions remained constant between 1988 and 2011.

Conclusions

severity of endometriosis does not increase between 24 and 44 years of age, suggesting that growth is limited by intrinsic or extrinsic factors. Severity was not lower in women with a previous pregnancy.

What is new

considering the time needed for lesions to become symptomatic together with the diagnostic delay, the decreasing number of laparoscopies after age 28 is compatible with a progressively declining risk of initiating endometriosis lesions after menarche, the remaining women being progessively less susceptible.

Surgical management of endometriosis-associated pain

Endometriosis and pelvic pain are associated. However, only half of the subtle and typical, and not all cystic and deep lesions are painful. The mechanism of the pain is explained by cyclical trauma and repair, an inflammatory reaction, activation of nociceptors up to 2.7 cm distance, painful adhesions and neural infiltration. The relationship between the severity of lesions and pain is variable. Diagnosis of the many causes requires laparoscopy and expertise. Imaging cannot exclude endometriosis. Surgical removal is the treatment of choice. Medical therapy without a diagnosis risks missing pathology and chronification of pain if not 100% effective. Indications and techniques of surgery are described as expert opinion since randomised controlled trials were not performed for ethical reasons, since not suited for multimorbidity while a control group is poorly accepted. Subtle endometriosis needs destruction since some cause pain or progress to more severe disease. Typical lesions need excision or vaporisation since depth can be misjudged by inspection. Painful cystic ovarian endometriosis needs adhesiolysis and either destruction of the lining or excision of the cyst wall, taking care to avoid ovarian damage. Cysts larger than 6cm need a 2 step technique or an ovariectomy. Excision of deep endometriosis is difficult and complication prone surgery involving bladder, ureter, and bowel surgery varying from excision and suturing, disc excision with a circular stapler and resection anastomosis. Completeness of excision, prevention of postoperative adhesions and recurrences of endometriosis, and the indication to explore large somatic nerves will be discussed.

Pathogenesis Based Diagnosis and Treatment of Endometriosis

Understanding the pathophysiology of endometriosis is changing our diagnosis and treatment. Endometriosis lesions are clones of specific cells, with variable characteristics as aromatase activity and progesterone resistance. Therefore the GE theory postulates GE incidents to start endometriosis, which thus is different from implanted endometrium. The subsequent growth in the specific environment of the peritoneal cavity is associated with angiogenesis, inflammation, immunologic changes and bleeding in the lesions causing fibrosis. Fibrosis will stop the growth and lesions look burnt out. The pain caused by endometriosis lesions is variable: some lesions are not painful while other lesions cause neuroinflammation at distance up to 28 mm. Diagnosis of endometriosis is made by laparoscopy, following an experience guided clinical decision, based on history, symptoms, clinical exam and imaging. Biochemical markers are not useful. For deep endometriosis, imaging is important before surgery, notwithstanding rather poor predictive values when confidence limits, the prevalence of the disease and the absence of stratification of lesions by size, localization and depth of infiltration, are considered. Surgery of endometriosis is based on recognition and excision. Since the surrounding fibrosis belongs to the body with limited infiltration by endometriosis, a rim of fibrosis can be left without safety margins. For deep endometriosis, this results in a conservative excision eventually with discoid excision or short bowel resections. For cystic ovarian endometriosis superficial destruction, if complete, should be sufficient. Understanding pathophysiology is important for the discussion of early intervention during adolescence. Considering neuroinflammation at distance, the indication to explore large somatic nerves should be reconsidered. Also, medical therapy of endometriosis has to be reconsidered since the variability of lesions results in a variable response, some lesions not requiring estrogens for growth and some being progesterone resistant. If the onset of endometriosis is driven by oxidative stress from retrograde menstruation and the peritoneal microbiome, medical therapy could prevent new lesions and becomes indicated after surgery.