OC22.02: Diagnostic accuracy of the transvaginal ultrasound “sliding sign”, direct visualisation and combination of both for the prediction of deep infiltrating endometriosis of the rectum and the rectosigmoid

1. To evaluate the diagnostic accuracy of transvaginal ultrasound (TVS) direct visualisation (DV) of rectal/rectosigmoid (RS) nodules compared to the "sliding sign" (SS) to predict deep infiltrating endometriosis (DIE) of the rectum ® and the RS during laparoscopy. 2.To evaluate the diagnostic accuracy of the combination of both techniques (DV+SS) to predict DIE of the R or the RS. Multicentre prospective observational study from January 2009 to February 2017,including patients with suspected endometriosis. All women underwent TVS to evaluate the “sliding sign” or if a nodule within the rectal/rectosigmoid wall was visualised, followed by laparoscopic surgery. The association between the SS and the DV during the TVS were correlated to the presence of rectal/rectosigmoid DIE at laparoscopy. Fisher's exact test was used for analysis. Complete TVS and laparoscopic data were available for 376 women. 76/376 (20.21%) women had rectal and/or rectosigmoid DIE at laparoscopy. The accuracy, sensitivity, specificity, PPV and NPV for direct visualisation of rectal/rectosigmoid nodules was significantly higher than the negative “sliding sign” in the prediction of DIE affecting the rectum/rectosigmoid (91.2% vs. 87%, 86.8% vs. 73.7%, 92.3% vs. 9.03%, 74.2% vs. 65.9%, 96.5% vs. 93.1%) (p<0.05). The co-occurrence of a negative SS and the DV of a rectal/rectosigmoid nodule showed a higher specificity and positive predictive values (95.3% and 79.1%, respectively), but lower sensitivity than both the SS (69.7% vs. 73.7%) or the DV of the nodules alone (69.7% vs. 86.8%). In expert hands, direct visualisation of rectal or rectosigmoid nodules using transvaginal ultrasound scan is an accurate tool to rule-in the presence of rectal/rectosigmoid DIE with similar results to laparoscopic evaluation. The combination of both techniques (direct visualisation of rectal or rectosigmoid nodules and the sliding sign) is a reliable method to rule-out rectal/rectosigmoid DIE.