OP34.06: Does the uterine “sliding sign” alone outperform direct visualisation using sonovaginography for the prediction of rectal/rectosigmoid deep infiltrating endometriosis?

A negative uterine “sliding sign” (i.e. POD obliteration/uterorectal adhesions) is known to be significantly associated with rectal deep infiltrating endometriosis (DIE). We aim to compare the performance of the “sliding sign” alone to direct visualisation using sonovaginography (SVG) for the prediction of rectal/rectosigmoid DIE. Multicentre prospective observational study undertaken between from January 2009 to February 2013, which included women with suspected endometriosis. All women included in the analysis underwent TVS to ascertain whether the “sliding sign” was positive or negative, followed by SVG and laparoscopic surgery for endometriosis. The association between a negative uterine “sliding sign” alone and the presence of rectal/rectosigmoid DIE at laparoscopy was then analysed using Fisher's exact test. This was compared to direct visualisation of rectal/rectosigmoid DIE using SVG. Complete ultrasound and laparoscopic data were available for 189/220 (86%) women. POD obliteration was present in 47/189 (25%) and rectal and/or rectosigmoid DIE was noted in 43/189 (23%) of women at laparoscopy. The accuracy, sensitivity, specificity, PPV, and NPV for a negative uterine “sliding sign” vs. SVG in the prediction of DIE affecting the rectum/rectosigmoid were 88.4% vs. 92%, 74% vs. 88%, 93% vs. 93%, 74% vs. 79%, vs. 93%/97%, respectively. There were 11/43 (26%) false negative cases, where the uterine “sliding sign” was positive and rectal DIE was confirmed at laparoscopy. SVG outperforms the negative uterine “sliding sign” in the prediction of rectal/rectosigmoid DIE.