P17.01: The association between pouch of Douglas obliteration at TVS and surgical findings at laparoscopy in women with suspected endometriosis

To determine the association between the presence of pouch of Douglas (POD) obliteration at transvaginal ulatrsound (TVS) and surgical findings at laparoscopy in women with endometriosis. Multi-centre prospective observational study undertaken from January 2009 to February 2013. This study included women with symptoms of chronic pelvic pain +/− history of endometriosis, planned for laparoscopic endometriosis surgery. All women underwent TVS prior to laparoscopy to determine whether POD obliteration was present using the “sliding sign”. Presence of the following surgical features were recorded at the time of laparoscopy: ovarian mobility, endometrioma/s, deep infiltrating endometriotic (DIE) nodules affecting the anterior rectum, rectosigmoid colon, rectovaginal septum, vagina and/or uterosacral ligaments. The association between POD obliteration at TVS and surgical findings at laparoscopy was then analyzed. 189 consecutive women with TVS and laparoscopic outcomes were included in the final analysis. At TVS, 40/189 (21.2%) women had a negative “sliding sign”, indicating POD obliteration. The association between POD obliteration at TVS and surgical findings was significant for the following features: right and left ovarian fixation (p = 8.1E-10 and 3.4E-11, respectively), right and left ovarian endometrioma (p = 2.6E-06 and 1.8E-05, respectively), DIE nodules in general (p = 1.1E-18) and DIE nodules specifically involving the anterior rectum, rectosigmoid colon, and left uterosacral ligament (p = 5.7E-13, 2.5E-05, 0.005, respectively). The need for bowel surgery was also significantly associated with POD obliteration at TVS (p = 5.4E-15). This study helps to define the surgical findings that may be associated with a negative “sliding sign”, or POD obliteration, during TVS. The pre-operative identification of TVS markers such as POD obliteration may alert the clinician to the possibility of difficult endometriosis surgery, which may extend beyond POD obliteration.