The importance of systematic ultrasound evaluation for women with potential endometriosis

For some, endometriosis represents a chronic, waxing and waning disease that can be associated with significant morbidity. Endometriosis embodies a substantial number of gynaecological presentations for symptoms ranging from pelvic pain to dyschezia. It is estimated that up to 10%1 of women in their reproductive years have endometriosis. In addition, the average delay from symptoms to diagnosis and definitive treatment, is estimated to be 7–12 years.2 Not only can quality of life be significantly impacted but Nnoaham et al.3 also demonstrated the negative effect endometriosis can have on productivity in the workplace, with up to 11 h of work per woman per week lost due to endometriosis. Transvaginal ultrasound (TVS) in experienced hands is the first-line diagnostic tool of choice when assessing the pelvis of a woman with suspected endometriosis.4 The impact that TVS is having on the surgical management of endometriosis cannot be understated.5 Thanks largely to innovations in ultrasound technologies and techniques, the detection of endometriosis and in particular deep infiltrating endometriosis (DIE) is now possible.6 Recent progress in the identification of disease location and extent using TVS has meant that appropriate pre-operative counselling and planning of surgical procedures can be optimised. For some women, this also means avoiding surgical intervention and its potential morbidities.7 The use of TVS by an experienced operator, not only can be diagnostic but also facilitate good clinical practice. For example, in symptomatic women if the TVS demonstrates both ovaries to be freely mobile, with no signs of DIE seen in either the anterior or posterior pelvic compartments and the pouch of Douglas (POD) to be not obliterated,8 then it may be worthwhile considering non-surgical interventions to avoid laparoscopy. If, however, the TVS demonstrates ‘kissing’ non-mobile ovaries, POD obliteration and/or the presence of DIE in symptomatic women, then surgical intervention is indicated. In circumstances where there is DIE involvement of the rectum/recto-sigmoid/sigmoid colon, precise pre-operative counselling as well as the potential involvement of other surgical subspecialties where necessary (e.g. colorectal surgeons) maximises surgical outcomes. Such definitive surgical planning and execution have the added benefit of breaking the cycle of recurrent laparoscopies, which can be the norm for some women who do not have access to high quality ultrasound. Historically, significant heterogeneity in the classification and diagnosis of endometriosis on ultrasound has limited the integration of different research findings into clinical practice. It is hoped that consistent terminology will allow more meaningful comparisons in future studies as well as facilitate multicentre research. In 2016, Guerriero and Condous et al.9 proposed a consensus opinion on terms, definitions and measurements for the description of sonographic features of the different phenotypes of endometriosis. Published in Ultrasound in Obstetrics and Gynaecology (International Society of Obstetrics and Gynaecology's (ISUOG) official journal), this international collaboration had 29 contributors from five continents and details a four-step systematic approach utilising dynamic TVS for an exhaustive sonographic evaluation for women with potential pelvic endometriosis. In this four-step process, the first step is described as a routine evaluation of the uterus and adnexal regions, including noting any sonographic signs of adenomyosis and/or endometrioma(s). Guerriero and Condous et al. propose that endometriomas should be described using the International Ovarian Tumor Analysis (IOTA) terminology.10 Step two involves the evaluation of transvaginal sonographic ‘soft markers’, such as site-specific tenderness and ovarian mobility. It is argued that superficial endometriosis is more likely in the presence of such soft markers. In step three, the sonographer/sonologist assesses for POD involvement by determining if the anterior rectum/recto-sigmoid fails to slide freely against the retro-cervix (RC) and/or posterior uterine fundus (PUF) (i.e. a negative ‘sliding sign’). If the bowel fails to slide freely over one of these distinct anatomical areas (RC and/or PUF), then the POD is predicted to be obliterated. Finally, step four defines a sonographic evaluation for DIE nodules in both the anterior (urinary bladder, uterovesical region, ureters) and posterior (rectovaginal septum, posterior vaginal fornix, uterosacral ligaments, anterior rectum, recto-sigmoid junction, sigmoid colon) compartments. It is suggested that a non-empty bladder will facilitate the evaluation of bladder nodules. Utilising a systematic, consistent approach to the ultrasound evaluation of women with potentially underlying endometriosis could improve both the pre-treatment detection of the disease, justify management pathways for women with endometriosis, and have an impact on disease morbidity. Guerriero and Condous et al. describe a rigorous, detailed method, which should be adopted by sonographers/sonologists looking to develop and improve their evaluation of the pelvis in women with chronic pelvic pain. They conclude that ‘we hope that the terms and definitions suggested will be adopted in centres around the world. This would result in consistent use of nomenclature when describing the ultrasound location and extent of endometriosis. We believe that the standardisation of terminology should allow meaningful comparisons between future studies in women with an ultrasound diagnosis of endometriosis and should facilitate multicentre studies’.