P10.09: The prevalence of deep infiltrating endometriosis (DE) lesions in patients with and without endometrioma

It is well known that DE is still under diagnosed in patients with endometrioma on transvaginal ultrasound (TVUS). Many cases of DE without endometrioma are diagnosed only at laparoscopy. This study aims to examine the prevalence of DE in patients with and without endometrioma and to determine how well TVUS performs in detection of DE lesions. We studied 114 patients who had surgery for diagnosis of DE following TVUS and sonovaginography. These patients were categorised into 2 groups based on whether TVUS had demonstrated presence of endometrioma or not. Of the 114 patients with severe DE in the study, 59 (52%) had endometrioma and 55 (48%) did not have endometrioma. In patients with severe DE in the presence of endometrioma, 51 (86%) had obliteration of pouch of Douglas (POD), 56 (95%) had uterosacral (USL) disease, 26 (44%) had bowel tethering/nodule, 8 (14%) had rectovaginal septum (RVS) lesion, and 3 (5%) had vaginal lesion. In patients with severe DE in the absence of endometrioma, 32 (58%) had obliteration of POD, 51 (93%) had USL disease, 30 (55%) had bowel tethering/nodule, 13 (24%) had rectovaginal septum lesion, and 11 (20%) had vaginal lesion. The sensitivity, specificity, positive predictive value and negative predictive value were calculated for individual DE lesions as well as for overall detection, using surgery as gold standard. This study shows that careful transvaginal assessment for DE performs well in detection and mapping of DE lesions. The study findings appear to compare well with some of the recent studies.