Response to Dennerstein letter: Bowel resection for severe endometriosis: an Australian series of 177 cases

Dear Editor, With respect, Dennerstein1 raises two issues with our paper.2 Firstly, he appears to consider the necessity for bowel resection in cases of endometriosis involving the bowel is rare. We disagree. Such cases are being increasingly reported. Since 2008, Medline lists at least 45 publications with reference to bowel resection and endometriosis. The issue is of sufficient significance that institutions from the UK, Europe and the USA have written on the benefits of treating deep invasive endometriosis in specialised units with access to multi-specialty surgical expertise, particularly colo-rectal surgeons.3 Whilst we acknowledge that definitive data on the treatment of colo-rectal endometriosis are lacking, increasing evidence from around the world points to the benefits of an individualised approach and increasingly, surgical intervention, particularly for those wishing to conceive. Aggressive surgical intervention incorporating bowel resection, in those patients where it is appropriate, appears to significantly decrease pain scores and lower recurrence rates4 and enhance pregnancy prospects (both spontaneous and via assisted conception). Endometriosis has a stage-related effect on fertility. Unsurprisingly, the removal of significant disease (including bowel involvement) dramatically improves pregnancy prospects. Our data, presented at the World Conference on Endometriosis in 2008, revealed a 60% pregnancy rate in a profoundly infertile population following bowel resection.5 Two further studies published during 2009 have demonstrated pregnancy rates very similar to our data, in support of our approach.6,7 We agree further controlled trials will be unusually difficult, to the extent they are unlikely to be performed. Secondly, Dennerstein postulates that medical management with DMPA is a superior alternative in management for (presumably) most women. Again, we disagree. DMPA may be a useful adjunct to a management plan for endometriosis, although is only of use in those patients who do not wish to conceive and are happy to maintain compliance with three monthly injections. Bone loss, which may be at least partially reversible, remains a concern for many. These issues are illustrated coincidentally and strikingly in a report in the same edition of the Journal as Dennerstein’s letter.8 In that randomised controlled trial for moderate to severe endometriosis comparing DMPA to Mirena, less than half of the DMPA group remained on therapy for 3 years. Additionally, bone loss was a significant finding in the DMPA group. In the 41 years of Dennerstein’s practice, the age of menarche has dropped, whilst the age at first conception has increased. His view that endometriosis may be linked to the ‘number of ovulations’ may have some validity and would support the notion of increased prevalence and severity. We postulate that if Dennerstein were to continue in practice for another 41 years, it is highly likely he would see more cases of bowel endometriosis and DMPA is unlikely to be the answer for many of those women.