Role of Surgery in Endometriosis-Associated Subfertility

Nicola Berlanda, MD; Paolo Vercellini, MD; Edgardo Somigliana, MD, PhD; Maria Pina Frattaruolo, MD; Laura Buggio, MD; Umberto Gattei, MD


Semin Reprod Med. 2013;31(2):133-143. 

In This Article

Comment: The Therapeutic Equipoise Principle

According to the available knowledge, surgical treatment of endometriosis may allow a spontaneous conception in about one preoperatively infertile woman out of four. One possible exception is surgery for endometriotic ovarian cysts, with a purported mean postoperative pregnancy rate of ~50%.

However, whereas the marginal effect of peritoneal endometriosis ablation has been defined based on the results of two multicenter RCTs, more data from adequately designed comparative studies are needed to assess the effect of surgery specifically in subfertile women with ovarian endometriomas. In fact, the just reported mean postoperative pregnancy rate is most likely an overestimate due to multiple confounding factors including selection bias (inclusion of women who were not necessarily infertile) and publication bias (surgeons with suboptimal outcomes may be less willing to submit their data and may be less likely to have them published). Moreover, exclusion from the analysis of subjects lost to follow-up may have inflated the benefit of surgery because dropouts notoriously have a worse prognosis. The number of women with uni- or bilateral cysts is rarely specified, few authors indicated how many patients achieved a pregnancy postoperatively by means of IVF, and, again, lack of an adequately generated control group impedes measurement of the difference between postoperative and background spontaneous pregnancy rates.[28]

In light of all these considerations, it is not possible to exclude that the effect of endometriotic cysts removal is well inferior to the alleged 50%. On the other side, ultrasonographic misdiagnosis of endometriomas is infrequent, thus avoiding the problem of the unreliable preoperative diagnosis of peritoneal implants.

With regard to subfertile women with rectovaginal endometriosis, given the complexity and the relatively low prevalence of the condition, it appears improbable that adequately sized RCTs will ever be conducted with the objective of comparing surgery with or without excision of deep plaques.

In general, speculations on the impact of different lesion types in determining a reduction in the probability of conception may sway from the possibility that, in women with undamaged tubes, the effect of surgery for endometriosis-associated subfertility may be similar (and limited) in different clinical conditions and stages. This is in line with the results observed in two large clinical databases, regardless of lesion site.[84,85]

In our opinion, the decision to perform surgery in subfertile women with endometriosis should result from a balance between the pros and cons of surgery, that is, between the absolute benefit increase of a procedure, its related morbidity, overall costs, and available alternatives (e.g., IVF). In addition, when defining such a therapeutic equipoise, the couple's motivation toward offspring should be carefully weighed. Indeed, not all women are equally willing to undertake the same distressing and painful surgical journey that will lead to a conception in only a minority of cases. Finally, the evidence accumulating on an increased obstetric risk in pregnancies in women with endometriosis should be communicated.[85,86,87]

Although a wise therapeutic answer must not be focused just on the surgical aspects of the problem, and in spite of the several uncertainties surrounding the field of endometriosis-associated subfertility, some conclusions can be drawn on which a common agreement seems to exist:[9,14,28]

  1. The choice of performing a laparoscopy in asymptomatic patients with "unexplained infertility" should be carefully weighed because it is most likely that endometriosis, if present, would be minimal or mild. In this condition the effect of surgery on fertility is fairly limited; therefore, even if risks are also limited, the overall benefit-to-harm cost ratio may be unfavorable.

  2. First-line surgery is justified in the case of large (>4 cm) endometriomas. Cyst removal allows histologic examination and seems associated with an appreciable absolute benefit (i.e., pregnancy rate increase over background rate). However, a careful technique should be adopted, implementing the principles of microsurgery with the objective of limiting the apparently unavoidable gonadal damage.

  3. First-line surgery for rectovaginal endometriosis must be cautiously discussed with the patient after detailed counseling about potential morbidity. Whereas excision of peritoneal and ovarian endometriosis is generally a relatively easy and safe procedure that can be performed by many gynecologists, excision of rectovaginal nodules and plaques is risky, particularly in the hands of the inexperienced. Indeed, the probability of complications increases with the level of radicality but is also related to the surgeon's capability.
    Women must be informed that the likelihood of spontaneous conception after surgery is about one in four, but it is uncertain whether removal of rectovaginal lesions is of any major benefit for reproductive performance, as it may not be excluded that the effect on fertility is due to treatment of concomitant peritoneal and ovarian disease.[28,43,50,52] Elective rectosigmoid resection may be indicated for different particular conditions (e.g., bowel stenosis, intolerable dyschezia, cyclic hematochezia, severe anatomical distortion), but not for infertility per se.
    Thus the alternatives include expectant management, excision of peritoneal and ovarian lesions without rectovaginal plaque removal, radical surgery with or without rectosigmoid resection, and IVF with or without pre-ART surgery. None of these options is supported by robust evidence of superiority over the others. Therefore, the final choice should be based on patient's preference taking into considerations other clinical conditions such as the severity of pain and the coexistence of additional infertility factors. The woman must be informed that, even if not planned in advance, rectal resection may prove unavoidable following inadvertent perforation or owing to technical difficulties. Moreover, she should know that rectovaginal lesions are not progressive in the vast majority of cases.[88] Clearly, this is the most difficult situation in the entire scenario of surgical treatment for endometriosis-associated subfertility because many factors, but few robust data, may tip the balance in favor of intervention versus abstention.

  4. In the absence of large or complex ovarian cysts, a prudent approach should be adopted toward repeated surgery in asymptomatic patients with recurrent endometriosis. In fact, not only IVF seems at least not inferior to surgery, but the possibility of irreversible gonadal damage may not be excluded. Moreover, surgery for recurrent disease after previous procedures may be less effective as well as more difficult and risky, again leading to an unfavorable overall balance.

  5. Surgery remains the only therapeutic option when moderate to severe pain is also present, and patients prefer spontaneous conception over IVF. Although pain relapse is frequent,[89] lesions and adhesions excision may allow relief of symptoms for a sufficient period of time during which medical treatment is not necessary and pregnancy may be attempted.

The introduction of laparoscopy and the evolution of surgical techniques for infertility, namely, suture materials, fenestration-vaporization versus stripping of cyst pseudocapsule, and measures to prevent adhesions, seem to have failed in substantially increasing the probability of achieving a pregnancy after first- or second-line surgery for endometriosis as compared with 30 years ago.[90] In spite of this, efforts toward amelioration of reparative surgery for endometriosis must not be withdrawn. What is indeed badly needed is a correct methodological approach to assess adequately the concrete effects of all these techniques, instrumentation, and measures. Moreover, systematic referral of infertile patients to large centers specializing in endometriosis treatment should be fostered, with the objective of offering them all the possible therapeutic alternatives, without the inherent limits related to the type of practice of an individual gynecologist. In fact, different physicians may be prone to indicate surgery or IVF based on personal experience, capabilities, and economic interests, more than on objective evidence.