Anatomical distribution of endometriosis: A cross‐sectional analysis of transvaginal ultrasound in symptomatic patients

Abstract

PurposeThe anatomical distribution of deep endometriosis (DE) is essential in treating patients with symptoms associated with the disease. There is an evidence gap in correlating clinical features and symptoms with disease patterns. The study aimed at determining DE anatomic distribution based on advanced transvaginal ultrasound and describe the relationship with symptoms obtained with the World Endometriosis Foundation Questionnaire.MethodsA cross‐sectional study included 549 ultrasound results and 370 questionnaire responses between July 2018 and January 2021. Descriptive statistics are presented. Continuous variables were compared by a simple t‐test and ANOVA and categorical variables by the chi‐squared test. Logistic regression and R2 values summarised the relationship between positive ultrasound and possible predictor variables (software SAS version 9.4).ResultsThe anatomical locations with signs of endometriosis on ultrasound were the right uterosacral ligament (USL) 23.3% (n = 128), left USL 21.3% (n = 117) and bowel 19.1% (n = 105). Endometriomas in the right and left ovaries (14%, n = 77, and 14.7%, n = 81 respectively), superficial endometriosis in 15.5% (n = 85), torus uterinus in 11.7% (n = 64), Pouch of Douglas (POD) in 9.7% (n = 53), rectovaginal septum in 4.2% (n = 23), vaginal fornix in 3.5% (n = 19). A negative ‘sliding‐sign’ was noted in 25.3% (n = 139), and ovarian medial immobility was noted frequently (left 20.2%, n = 111 and right 16.9%, n = 93). Dyspareunia, dysmenorrhoea, infertility and family history were associated with endometriosis lesions (P < 0.05). Prediction models based on symptomatology presented low discriminatory power.DiscussionThis large real‐life cohort associating the description of the anatomical distribution of endometriosis as seen on advanced TVS in symptomatic patients confirmed that uterosacral ligaments, torus uterinus, ovaries and bowel represent the most common anatomical sites of endometriosis. Also, the dynamic abnormalities elicited via ultrasound, such as the uterus ‘sliding‐sign’ and ovarian mobility, remain common. The knowledge of the general locations of identifiable endometriosis on ultrasound and the dynamic abnormalities is essential to sonologists and sonographers in implementing advanced TVS protocols to detect endometriosis. In addition, the different presentations of dyspareunia can be associated with USL and bowel endometriosis. Subfertility might also be associated with USL, ovarian and bowel endometriosis. Nevertheless, prediction models showed suboptimal results.ConclusionsEndometriosis is mainly distributed in USLs, bowel and ovaries. POD obliteration is frequent. Symptoms can be associated with anatomic locations; however, prediction models showed low clinical applicability.

The accuracy of ultrasound compared to magnetic resonance imaging in the diagnosis of deep infiltrating endometriosis: A narrative review

“…Several studies investigated the diagnostic accuracy of TVUS and MRI with results summarised in Table 2. The performance across both modalities was high for locating and mapping DE, however neither provided definitive diagnosis due to the operator dependency limitations of TVUS and interpretive limitations of MRI 11,32 . Further research may be beneficial for mapping and locating DE using other modalities such as transrectal ultrasound or contrast‐enhanced imaging 11,32 .…”

“…With the aid of contrast, the accuracy of MSCT in diagnosing caecal and ileal endometriosis is reportedly superior to MRI with improved visualisation of endometriotic nodules and associated fibrosis 34 . It is to be noted that limitations to MSCT include exposure to radiation for patients at reproductive ages and inaccuracy exists for diagnosing other DE locations such as ovaries and USL 11,32 …”

“…The performance across both modalities was high for locating and mapping DE, however neither provided definitive diagnosis due to the operator dependency limitations of TVUS and interpretive limitations of MRI. 11,32 Further research may be beneficial for mapping and locating DE using other modalities such as transrectal ultrasound or contrast-enhanced imaging. 11,32 With access to T1.5 and above MRI equipment possibly restricted, particularly in rural and remote areas of the community, further investigation into the use of multi slice computed tomography (MSCT) enteroclysis scans is suggested, as the current research, though minimal, has demonstrated excellent results (sensitivity, specificity and accuracy all >95%) when compared with rectal contrast TVUS.…”

“…11,32 Further research may be beneficial for mapping and locating DE using other modalities such as transrectal ultrasound or contrast-enhanced imaging. 11,32 With access to T1.5 and above MRI equipment possibly restricted, particularly in rural and remote areas of the community, further investigation into the use of multi slice computed tomography (MSCT) enteroclysis scans is suggested, as the current research, though minimal, has demonstrated excellent results (sensitivity, specificity and accuracy all >95%) when compared with rectal contrast TVUS. 11,[33][34][35] With the aid of contrast, the accuracy of MSCT in diagnosing caecal and ileal endometriosis is reportedly superior to MRI with improved visualisation of endometriotic nodules and associated fibrosis.…”

Evidence‐based innovation in ultrasound practice

“…Rocha et al 1 present an analysis of a large cohort of women investigated for endometriosis in which they evaluated the anatomical distribution of endometriosis with ultrasound and tested a recommended prediction model that used a patientadministered questionnaire from the World Endometriosis Research Foundation. They found the performance of the questionnaire added little clinical value and suggested further refinement of the questionnaire may be needed.…”