OP15.07: Old and new protagonists on the ultrasound scene for the diagnosis of deep pelvic endometriosis: a systematic literature review and meta‐analysis

Transvaginal sonography (TVS) is considered the first line diagnostic technique for deep pelvic endometriosis (DPE), even if magnetic resonance imaging (MRI) seems more accurate for DPE severity assessment. As routine MRI may not be cost effective to evaluate DPE, new modified-techniques are emerging to reach MRI-accuracy using ultrasound (US) imaging. Aim of our study was to set an evidence based approach to define the best ultrasound technique for DPE study. We performed a systematic literature review and meta-analysis of all studies providing complete data about all US imaging techniques for diagnosis of DPE. The US techniques included are TVS, rectal ultrasonography (RES), saline contrast sonovaginography (SCSV), tenderness-guided TVS (TG-TVS), rectal water contrast-TVS (RWC-TVS), TVS with bowel-preparation, TVS sliding-sign. We included 35 manuscripts, of which 32 eligible for statistical evaluation. Specificity (SP) of TVS was greater than 85% for all DPE sites while sensitivity (SE) ranged between 50% (bladder, vaginal-wall and rectovaginal-septum) and 84% (rectum-sigmoid). The TG-TVS resulted more accurate for bladder lesions, while RES and RWC-TVS seemed superior to TVS for rectosigmoid endometriosis (SP = 92.6%,SE = 92.6%). In addition, RCW-TVS (SE = 97.1%) and SCVS (SP = 84.5%) demonstrated promising in rectovaginal-septum endometriosis assessment. SCVS appeared the most accurate method for the diagnosis of uterosacral-ligament, vaginal-wall and vaginal-fornix endometriosis, while RES and TVS-sliding sign showed a twice higher sensitivity than TVS in evaluating pouch of Douglas endometriosis. TVS-modified techniques and RES should be performed by highly skilled sonographers in a dedicated setting. These techniques should be offered when standard TVS is non-conclusive for DPE localisation. In adequate settings for endometriosis diagnosis, trained clinicians may offer second-level US scans with a similar or better accuracy than MRI.