P18.04: Transvaginal ultrasound (TVS) combined evaluation of pelvic sites of implants and the “sliding sign” to predict likelihood of rectal/rectosigmoid deep infiltrating endometriosis (DIE) at laparoscopy

To develop of a logistic regression model using TVS findings to predict the presence of rectal/rectosigmoid DIE during laparoscopy. Multicentre prospective observational study undertaken between from January 2009 to February 2017 including women with suspected endometriosis. All women had a TVS to evaluate the presence of endometriotic implants in 6 pelvic sites (rectum/rectosigmoid, rectovaginal septum, uterosacral ligaments, bladder, ureters and ovaries) and the “sliding sign”, before having a laparoscopic procedure for excision of endometriosis. Stepwise logistic regression was used to select the variables for model fitting. Complete TVS and laparoscopic data were available for 376 women. 76/376 (20.21%) were confirmed to have rectal and/or rectosigmoid DIE at laparoscopy. The demographic and historical variables and findings at TVS were evaluated and eventually, only two variables were found to be significant according to the logistic regression analysis: direct visualisation of rectal/rectosigmoid DIE and negative “sliding sign” at US. The TVS combined evaluation of “sliding sign” and direct evaluation of the rectum and rectosigmoid areas had an Accuracy of 92.4%, Sensitivity 87%, Specificity 93.4%, PPV 80%, NPV 96% in our population. The most relevant TVS markers to predict bowel DIE involvement are the “sliding sign” and the direct evaluation of the rectal/rectosigmoid areas. In expert hands, the combined evaluation of both TVS markers is an accurate technique to predict rectal/rectosigmoid DIE, with similar results to laparoscopy.