Abstract and Introduction
Analysis of published series reveals that no more than a fourth of subfertile patients undergoing surgery for peritoneal endometriotic implants, rectovaginal endometriotic lesions, or recurrent endometriomas achieved conception spontaneously. First-line surgery for ovarian endometriotic cysts appears associated with a better reproductive performance, that is, a mean postoperative pregnancy rate of ~50%. At the same time, excision of endometriomas paradoxically seems to induce gonadal damage. With the exception of peritoneal disease, no randomized trials are available to assess the effect of surgery in subfertile women with endometriosis. Therefore, it is not possible to define the absolute benefit increase of the treatment of ovarian and rectovaginal lesions. The decision to undergo surgery for endometriosis-associated subfertility must be shared with the woman after detailed information and taking into account several additional conditions, such as presence of pain, large or complex adnexal masses, bowel or ureteral stenosis, and coexisting infertility factors. When considering surgery, a therapeutic equipoise should be reached that includes demonstrated benefits, potential morbidity, and costs of treatment alternatives. Particularly in case of recurrent endometriosis, in vitro fertilization should generally be preferred to surgery. The role of surgery in endometriosis-associated subfertility includes temporary pain relief in symptomatic women desiring a spontaneous conception.
A relation between endometriosis and subfertility has long been hypothesized based on epidemiologic evidence. In fact, in large published series, the prevalence of endometriosis among women with primary infertility was 9 to 50%,[1–3] compared with 1 to 7% among women undergoing tubal ligation (i.e., in subjects with proven fertility).[1,4–7] Moreover, the monthly fecundity rate in women with endometriosis has been reported to be reduced, ranging from 2% to 10%, as compared with 15 to 20% in fertile couples.[9–11]
Unfortunately, these epidemiologic observations constitute the only indirect evidence available concerning the association between endometriosis and subfertility. In fact, although several pathogenic mechanisms have been hypothesized, whether anatomical, biochemical, or endocrine, a causal relation has not yet been clearly demonstrated. The poor correlation observed between endometriosis stage, as evaluated by the American Society for Reproductive Medicine (ASRM) classification and reproductive performance,[12,13] seems to support the hypothesis that the distortion of the pelvic anatomy is not the sole factor involved. It is most likely that endometriosis-related subfertility results from the coexistence of different biological conditions.
As a consequence of this multifactorial origin, the clinical management of infertile women with endometriosis is often a challenging issue. In fact, one single treatment, either medical or surgical, that may simultaneously affect all the biological modifications induced by the disease is not available. With regard to reparative surgery, the major therapeutic goals are elimination of endometriotic lesions to reduce the inflammatory status, and removal of adhesions that, when involving the ovaries and/or the fallopian tubes, may impair the processes of ovulation and oocyte capture. However, surgery might not overcome the biomolecular alterations associated with chronic inflammation and infertility. Furthermore, the anatomical insults to reproductive function due to endometriosis, such as tubal damage and severe adnexal adhesions, might be irreversible or not completely reparable. Finally, the tendency of the disease to recur even after radical surgery is well known, confirming that, paradoxically, surgical eradication of all visible endometriotic lesions does not eradicate the disease.
Keeping these intrinsic limitations in mind, our purpose here is to review and synthesize the best available evidence, with the objective of assessing the effect of conservative surgery in infertile women with different endometriotic lesions. In fact, measuring the magnitude of the effect of surgery is of utmost importance to define a therapeutic balance among benefits, harms, and costs under various clinical conditions.
Semin Reprod Med. 2013;31(2):133-143. © 2013 Thieme Medical Publishers