OC20.06: Comparison of diagnostic accuracy of transvaginal ultrasound for deep endometriosis and pouch of Douglas obliteration in the presence and absence of ovarian endometriomas

We aim to evaluate and compare the diagnostic accuracy of deep endometriosis transvaginal ultrasound (DE TVS) in the presence and absence of ovarian endometriomas (OEs). This was a multicentre observational study of prospectively collected data from patients presenting with signs and symptoms of endometriosis from 2009-2017. Patients gave a detailed history, underwent DE TVS, then laparoscopy. During DE TVS, presence of OEs, ovarian immobility, DE, and POD obliteration were assessed. Visualization on laparoscopy and/or histological evidence of endometriosis was the reference standard. The diagnostic accuracy of DE TVS, including subgroup prevalence rates of DE and POD obliteration, was determined in patients with and without OEs. 410 patients were included. An OE was noted in 91, 22.2% patients (left: 66, 16.3%; right: 58, 14.2%; bilateral: 33, 8.2%). When comparing those with and without an OE, DE prevalence was 62/91, 68.1% and 81/313, 25.9%, respectively, and POD obliteration prevalence was 55/91, 60.4% and 31/313, 9.9%, respectively (p<0.001). There was better sensitivity for DE (85.5 vs 59.3%) and POD obliteration (81.8 vs 64.5%) with an OE present versus absent, respectively (p<0.001). Conversely, specificity was higher for DE (92.7 vs 79.3%, p<0.001) and POD obliteration (98.6 vs 88.6%, p = 0.13) with an OE absent vs present, respectively (image 1). The prevalence of DE and POD obliteration in patients without OEs is lower, but not negligible. Diagnostic accuracy of DE TVS is poorer in patients without OEs, which is not well-understood and concerning as many patients may be falsely reassured. 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.