OC02.03: Uterine sliding sign: a simple sonographic predictor for presence of deep infiltrating endometriosis of the rectum

In a recent study by Hudelist et al, UOG 2013, the authors concluded that the “uterine sliding sign” demonstrated by transvaginal sonography (TVS) was a simple predictor of deep infiltrating endometriosis (DIE) of the rectum in patients with symptoms suggestive of endometriosis. The aim of this is study was to apply this hypothesis, i.e. that a negative uterine “sliding sign” can predict DIE involving the bowel, in women reviewed in our Endogynaecology Unit. 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 uterine sliding sign technique. A negative sliding sign was recorded when the anterior rectum and/or rectosigmoid bowel did not glide smoothly across the retro-cervical region and/or posterior uterine fundus, respectively. The association between a negative uterine sliding sign at TVS and the surgical finding of rectosigmoid and/or anterior rectum DIE at laparoscopy was then analysed. At laparoscopy, 42/189 (22%) women had evidence of bowel DIE. 13/189 (7%) women had rectosigmoid DIE and 36/189 (19%) women had anterior rectum DIE. Skip bowel lesions involving the rectosigmoid and/or anterior rectum were present in 7/189 (3.7%). The sensitivity, specificity, PPV, and NPV for a negative TVS sliding sign in the prediction of DIE affecting the rectosigmoid and/or anterior rectum was 73%, 92%, 74%, and 92%, respectively. There were 11 false positive cases, where the TVS “sliding sign” was negative, however there was no evidence of bowel DIE at surgery. The findings from this study indicate that the TVS sliding sign is not a reliable predictor of bowel endometriosis, particularly when compared with the high accuracy of TVS as a stand-alone diagnostic tool in the direct visualisation of bowel endometriosis.