Bowel surgery as a fertility-enhancing procedure in patients with colorectal endometriosis: methodological, pathogenic and ethical issues

Bowel surgery for colorectal endometriosis is being promoted to infertile women without severe sub-occlusive symptoms, with the objective of improving the likelihood of conception. Contrary to rectal shaving, bowel surgery involving full-thickness disk excision and segmental resection entails opening of the intestinal lumen thus increasing the risk of postoperative infectious complications. About 1 in 10 patients undergoing colorectal resection for intestinal endometriosis will experience severe sequelae, including anastomotic dehiscence, rectovaginal fistula formation, and bladder and bowel denervation. Similar to other surgical procedures aiming at enhancing fertility in women with endometriosis, bowel surgery has been introduced into clinical practice without adequate evaluation through randomized controlled trials. According to systematic literature reviews based mainly on case series, the incremental gain of adding bowel procedures to standard surgery appears uncertain in terms of pregnancy rate after both natural attempts and IVF. Considering the methodological drawbacks and the high risk of bias in the available observational studies, it is not possible to exclude the suggestion that the benefit of colorectal surgery has been overestimated. Given the risk of harms to women's health and the important ethical implications, less emphasis should be put on strict statistical significance and more emphasis should be placed on the magnitude of the effect size. In this regard, the published data may not be generalizable, as the surgeons publishing their results may not be representative of all surgeons. Until the results of adequately designed and conducted RCTs are available, colorectal surgery with the sole intent of improving the reproductive performance of infertile patients with intestinal endometriosis should be performed exclusively within research settings and by highly experienced surgeons. Women should be informed about the uncertainties regarding the harms and benefits of bowel surgery in different clinical conditions, and preoperative counselling must be conducted impartially with the objective of achieving a truly shared medical decision.