Peritoneal endometriosis in women requesting reversal of sterilization

Epidemiology of Endometriosis in France: A Large, Nation-Wide Study Based on Hospital Discharge Data

We aimed to assess the prevalence of hospitalization for endometriosis in the general population in France and in each French region and to describe temporal trends, rehospitalization rates, and prevalence of the different types of endometriosis. The analyses were carried out on French hospital discharge data and covered the period 2008–2012 and a population of 14,239,197 women of childbearing age. In this population, the prevalence of hospitalization for endometriosis was 0.9%, ranging from 0.4% to 1.6% between regions. Endometriosis affected 1.5% of hospitalized women of childbearing age, ranging from 1.0% to 2.4% between regions. The number of patients hospitalized for endometriosis significantly increased over the study period (p < 0.01). Of these, 4.2% were rehospitalized at least once at one year: ranging from 2.7% to 6.3% between regions. The cumulative rehospitalization rate at 3 years was 6.9%. The types of endometriosis according to the procedures performed were as follows: ovarian (40–50%), peritoneal (20–30%), intestinal (10–20%), and ureteral or bladder (<10%), with significant differences between regions. This is the first detailed epidemiological study of endometriosis in France. Further studies are needed to assess the reasons for the increasing prevalence of endometriosis and for the significant differences in regional prevalence of this disease.

The aetiology and pathogenesis of endometriosis

It is 130 years since the first description of endometriosis and yet this enigmatic disease still continues to confound gynaecologists. In the last five years there has been evidence which suggests that endometriosis is a much more common finding in the pelvis than previously recognized and this has created conflict over the precise definition of the disease. Currently it is difficult for clinicians to be certain what constitutes endometriosis and what is the clinical and pathological significance of the visual diagnosis of the disease. This article will review the evidence about the pathological significance of the visual diagnosis of endometriosis. It will analyze the aetiological factors that predispose to the disease and evidence concerning its pathogenesis. Finally, it will discuss the evidence that points to a particular epithelium being the origin of endometriosis.

Epidemiology of endometriosis

This article summarizes present knowledge about the epidemiology of endometriosis. Surprisingly, little is known about the prevalence or risk factors of endometriosis, given the medical care and employment costs. Knowledge about the epidemiology of endometriosis is hampered by the inability to diagnose this disease in the general population. Based on a single cohort study, it is estimated that there is a 10% prevalence of endometriosis in the general population. Age is the only sociodemographic characteristic for which a consistent positive relationship has been observed. In general, the risk of endometriosis appears to increase for reproductive health factors that may relate to increased exposure to menstruation (i.e., shorter cycle length, longer duration of flow, or reduced parity). The risk appears to decrease for personal habits that may relate to decreased estrogen levels (i.e., smoking, exercise).

Is endometriosis a disease?

Recent comparative studies and developments in our understanding of the pathogenesis and pathophysiology of endometriosis have led to increasing doubts about whether it should always be considered a disease. Widespread use of laparoscopy for gynaecological investigation and treatment, recognition of non-pigmented lesions which are more active than classical implants, and the documentation of microscopic lesions in visually normal peritoneum, have all resulted in an increase in the frequency with which endometriosis is diagnosed. Recent studies suggest a prevalence of up to 80% in women complaining of infertility or pelvic pain, but also in up to 22% of fertile asymptomatic women undergoing sterilization. Perhaps it is a normal physiological variant, being present in such a high proportion of the population. Circumstantial evidence suggests this may be so, and the results with placebo treatment in controlled trials suggest that endometriosis is self-limiting and will regress or disappear spontaneously in 58% of women. The frequency and severity of symptoms which are often presumed to result from endometriosis do not correlate with the extent or site of lesions. Most women are pain-free. There is no dysmenorrhoea in up to 77%, no dyspareunia in up to 70%, and no pelvic pain at all in up to 61% of women with endometriosis. The pathophysiology of pain related to endometriosis is not understood. There is no medical or conservative surgical treatment that is wholly effective for symptom relief, and there is considerable placebo benefit. All treatments have risks or side-effects, and recurrent symptoms will develop in up to 45% of women within 5 years. For these reasons treatment should only be used where endometriosis fulfils the criteria of a disease, showing signs of progression with tissue damage or physiological disturbance. Asymptomatic endometriosis without tissue damage should not be considered a disease and should not be treated. Treatment of pain associated with minor endometriosis, or prophylactic treatment to prevent progression, must be regarded as empirical and not the specific requirement to control what is a questionable disease.

Role of peritoneal inflammation in endometriosis-associated infertility

This paper has discussed the evidence for the presence of infertility in patients with endometriosis and more critically reviewed some of the studies that have addressed the impact of various potential local peritoneal mechanisms that may lead to subfertility. Substantial evidence supports the notion that patients with endometriosis have reduced fecundability. Although several mechanisms, including, e.g., anatomic factors and ovulatory dysfunction, are possible, recent studies have pointed towards local inflammatory cells and their secretory products as being important mediators of subfertility. Ample evidence exists for the presence of an altered peritoneal inflammatory environment in patients with endometriosis. In addition, in vitro studies have identified peritoneal macrophages and their secretory products, specifically TNF-alpha as the most likely contributors to the reduced fecundability through effects on sperm function.