OC13.07: Ultrasound evaluation of pelvic deep infiltrating endometriosis (DIE): accuracy in differentiating rectal from sigmoid lesions

Rectal and sigmoid endometriosis lesions have surgically different approaches but also different postsurgical events and complications. The management and counseling of the affected patients is very different according also to the prevalent symptoms: pain and infertility. The aim of this study was to evaluate the accuracy in the differentiation of rectal from sigmoid DIE lesions by different sonographic approaches, compared to laparoscopical and histological findings. 114 patients with pelvic DIE underwent sonographic evaluation prior to laparoscopic surgery, using a transvaginal sectorial probe, first transvaginally (TVS) than transrectally (TRS). An accurate mapping of the localization of the disease was performed at sonographic examination and during laparoscopy. We described the endometriotic/fibrotic infiltrating tissue in terms of presence or absence on different sites of the intestinal tract: rectum (distal, medium, proximal), rectosigmoid junction and sigmoid wall. Size of the DIE lesions and invasion of the intestinal wall (serosa, muscolaris, mucosa) were reported by TVS/TRS and histology. The sensitivity in the diagnosis of endometriotic nodules of the distal rectal and sigmoid wall was 86% and 88% respectively. Whereas the accuracy in the diagnosis of rectovaginal septum nodules, in particular of those infiltrating the medial rectal wall and posterior vaginal fornix was significantly lower (68% and 73% respectively). Size of sigmoid lesions correlated with lumen stenosis, whereas size of the rectal lesions and of the RVS correlated with the extension to the parametria and urethral tract. TVS/TRS performed by skilled sonographer provide accurate informations about the presence and the extension of pelvic intestinal DIE. In particular it improves the diagnosis of the infiltration of the rectal wall and RVS, whereas large sigmoid or rectal lesions need to be evaluated by further diagnostic tools to grade intestinal lumen or urethral stenosis.