OC16.03: *The ovarian sliding sign is an important ultrasound marker for the prediction of laparoscopic surgery complexity

To determine the relationship between a negative ovarian sliding sign (i.e. fixed ovary) at transvaginal ultrasound (TVU) and surgical skill level required for laparoscopic endometriosis surgery, according to the Royal Australian and New Zealand College of Obstetricians and Gynaecologists/Australian Gynaecological Endoscopy & Surgery (RANZCOG/AGES) classification system. Multicentre retrospective diagnostic accuracy study (Oct 2019–Jan 2020) which included women with suspected pelvic endometriosis. All women underwent a systematic detailed transvaginal ultrasound (TVU) scan according to the International Deep Endometriosis Analysis group statement prior to laparoscopy. Ovarian mobility was assessed during real-time TVU using the ovarian sliding sign technique. The relationship between the preoperative ovarian sliding sign findings and associated RANZCOG/AGES surgery skill level (1-6) was then evaluated, with levels 1-3 representing generalist skill and levels 4-6 representing advanced skill. Complete ultrasound and laparoscopic data was available for 66 women. A total of 46/66 (70%) women required RANZCOG/AGES skill level >3 at the time of surgery. 26/66 (40%) had isolated superficial peritoneal endometriosis, 15/66 (23%) had an endometrioma, 13/66 (20%) had deep endometriosis and 13/66 (20%) had POD obliteration. A negative ovarian sliding sign at preoperative TVU demonstrated a high specificity (>90%) and PPV (>90%) for the prediction of need for advanced laparoscopic skill and thus should be considered an important ultrasound marker for surgical complexity and required surgical expertise when planning surgery for women with suspected endometriosis. OC16.03: Table 1. Prediction of laparoscopic RANZCOG/AGES skill level > 3 by negative ovarian sliding sign at TVU (n = 46)