To determine the optimal ultrasonographic screening method for rectal/rectosigmoid deep endometriosis: Ultrasound "sliding sign," transvaginal ultrasound direct visualization or both?

Introduction: The study aim was to evaluate the transvaginal sonography (TVS) "sliding sign" alone, direct visualization of the bowel with TVS, and the combination of both methods (ie "sliding sign" and direct visualization of the bowel), to determine the optimal TVS method for the prediction of rectal/rectosigmoid deep endometriosis (DE). Material and methods: Multicenter prospective observational study (January 2009-February 2017). All women underwent TVS to determine whether the "sliding sign" was positive/negative and whether rectal/rectosigmoid DE was present, followed by laparoscopic surgery. The association between a negative TVS "sliding sign" alone and the direct visualization of a rectal/rectosigmoid DE nodule alone during the TVS were correlated with the presence of rectal/rectosigmoid DE at laparoscopy. Accuracy, sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), and likelihood ratios (LRs) were evaluated. Data were analyzed using Fisher's exact test. Results: During the recruitment period, 410 consecutive women with suspected endometriosis were included. Complete TVS and laparoscopic surgical outcomes were available for 376 of the women (91.7%). Complete TVS and laparoscopic data were available for 376 women. Of the 376 women 76 (20.2%) had rectal/rectosigmoid DE at laparoscopy. The accuracy, sensitivity, specificity, PPV, NPV, positive and negative LRs for each method to predict bowel DE were: negative "sliding sign": 87%, 73.7%, 90.3%, 65.9%, 93.1%, 7.62, and 0.29, respectively; direct visualization: 91.0%, 86.8%, 92.3%, 74.2%, 96.5%, 11.3, and 0.14, respectively; combined approach: 90.2%, 69.7%, 95.3%, 79.1%, 92.6%, 14.94, and 0.32, respectively. A negative TVS "sliding sign" was significantly associated with the need for bowel surgery (P < 0.05). Conclusions: The combination of the TVS "sliding sign" and direct visualization of the bowel during TVS appears to provide the most accurate assessment for the identification of rectal/rectosigmoid DE preoperatively.