OP12.02: Deep endometriosis prevalence in the absence of ovarian endometrioma

In the preoperative evaluation of patients, a basic pelvic transvaginal ultrasound (TVS) can reliably predict the presence or absence of ovarian endometriomas. The visualisation of an endometrioma and the known association between endometriomas and deep endometriosis (DE) may lead to a subsequent, advanced TVS targeted at diagnosing DE. Unless the patient's symptoms and signs require further investigation, the preoperative workup might end here. We hypothesise that many cases of DE are being missed or unexpectedly diagnosed during surgery. Our aim is to determine the currently unknown prevalence of DE in patients without endometriomas. A retrospective observational study was done using a multicentre endometriosis database, including 408 entries collected in Sydney, Australia between 2009 and 2017. All patients underwent advanced TVS for DE and laparoscopy. Descriptive statistics were used to understand the prevalence of DE compared to the presence and absence of endometriomas. Ultrasound findings not confirmed on laparoscopy were removed from the analysis. Of the 408 participants, 153 (35.7%) had DE. The number of participants with an endometrioma was 98 (24.0%). In those with an endometrioma, 68 participants had DE (69.4%) (p < 0.001). The remaining 310 did not have an endometrioma. DE was present in 85 participants without an endometrioma (27.4%). The correlation between endometriomas and DE was confirmed. Further, a large proportion of participants (27.4%) had surgically-diagnosed DE in the absence of an endometrioma. As such, patients with symptoms and signs of endometriosis have a high likelihood of DE, even in the absence of endometriomas. This finding highlights the importance of a thorough preoperative evaluation, which should not necessarily end when a basic TVS fails to identify endometriomas. Please note: The publisher is not responsible for the content or functionality of any supporting information supplied by the authors. Any queries (other than missing content) should be directed to the corresponding author for the article.