TREATMENT OF ENDOMETRIOSIS
ENDOMETRIOSIS is the growth of endometrium outside the uterine cavity or myometrium (endometriotic implants), usually in the peritoneal cavity (Fig. 1). The question of how the tissue attains this abnormal placement is controversial, although the predominant theory is that retrograde menstruation is the cause. Additional factors that may be important in pathogenesis include immunologic abnormalities, endometrial disorders, and peritoneal dysfunction.
The principal manifestations of endometriosis are pelvic pain and infertility. The extent of the pain is influenced primarily by the location and depth of the endometriotic implant, with deep implants in highly innervated areas most consistently associated with pain. Infertility can result from the distortion of anatomical relations in the pelvis caused by fibrosis and the formation of adhesions. In addition, early-stage disease (characterized by implants alone) may impair fertility by means of a variety of substances produced by the implants or the surrounding tissue; such substances might include prostaglandins, cytokines and growth factors, or other embryotoxic factors.
EVALUATION OF TREATMENTS
FOR ENDOMETRIOSIS
In women with endometriosis, the efficacy of treatment has most often been measured by means of assessments of pain and infertility. Three factors are critical in evaluating pain in women with endometriosis during treatment trials: a validated pain scale, a time-dependent evaluation, and consideration of the effects of placebo or sham surgery. The measurement of fertility is also used to assess the effect of treatment. Although the occurrence of pregnancy may seem an objective criterion, it has several characteristics that make its use as an outcome variable problematic. First, multiple confounding factors often affect a woman’s fertility. In addition, pregnancy (like pain) is a time-dependent phenomenon. That is, the pregnancy rate will vary depending on the duration of follow-up. Finally, endometriosis rarely causes an absolute inability to conceive; thus, the rate of pregnancy in untreated women must be used as a basis for comparison.
In an attempt to predict prognosis, the severity of endometriosis has been classified by numerous staging systems. The revised classification system of the American Society for Reproductive Medicine, currently widely used, consists of four stages (I through IV), with higher-numbered stages representing more extensive disease of the reproductive structures .However, the classification scheme is limited in that it is designed to predict only the likelihood of future fertility. There is no correlation between the stage of disease and the degree of pain or the prognosis with treatment.