VP59.51: The importance of the ovarian sliding sign for prediction of surgical complexity when using the ultrasound‐based endometriosis staging system

The aim of this study was to determine whether a negative ovarian sliding sign at TVU may be useful for the identification of women who require laparoscopic ureterolysis and/or pelvic sidewall adhesiolysis preoperatively, that would otherwise be misclassified as < ultrasound-based endometriosis staging system III (UBESS III). Multicentre retrospective diagnostic accuracy study (Oct 2019–Jan 2020) which included women with suspected pelvic endometriosis. All women underwent a systematic detailed 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 and UBESS stage was assigned retrospectively. The relationship between UBESS stage, ovarian sliding sign at TVU and need for ureterolysis/adhesiolysis was then compared retrospectively. Complete ultrasound and laparoscopic data was available for 66 women. 26/66 (40%) had isolated 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 was associated with the need for pelvic sidewall/bowel adhesiolysis for 12/15 (80%) women classified as UBESS II and 10/12 (83%) women in UBESS III. Women with fixed ovaries at TVU (i.e. negative ovarian sliding sign) have increased risk of requiring ureterolysis and pelvic sidewall/bowel adhesiolysis, even in the absence of POD obliteration or bowel DE (i.e. UBESS III). A restructuring of the UBESS classification is needed, particularly with regard to the UBESS II category, in order to better reflect the important relationship between ovarian immobility and need for advanced laparoscopic procedures. VP59.51: Table 1.