The association between ultrasound-based ‘soft markers’ and endometriosis type/location: A prospective observational study

Society of Radiologists in Ultrasound Consensus on Routine Pelvic US for Endometriosis

Endometriosis is a prevalent and potentially debilitating condition that mostly affects individuals of reproductive age, and often has a substantial diagnostic delay. US is usually the first-line imaging modality used when patients report chronic pelvic pain or have issues of infertility, both common symptoms of endometriosis. Other than the visualization of an endometrioma, sonologists frequently do not appreciate endometriosis on routine transvaginal US images. Given a substantial body of literature describing techniques to depict endometriosis at US, the Society of Radiologists in Ultrasound convened a multidisciplinary panel of experts to make recommendations aimed at improving the screening process for endometriosis. The panel was composed of experts in the imaging and management of endometriosis, including radiologists, sonographers, gynecologists, reproductive endocrinologists, and minimally invasive gynecologic surgeons. A comprehensive literature review combined with a modified Delphi technique achieved a consensus. This statement defines the targeted screening population, describes techniques for augmenting pelvic US, establishes direct and indirect observations for endometriosis at US, creates an observational grading and reporting system, and makes recommendations for additional imaging and patient management. The panel recommends transvaginal US of the posterior compartment, observation of the relative positioning of the uterus and ovaries, and the uterine sliding sign maneuver to improve the detection of endometriosis. These additional techniques can be performed in 5 minutes or less and could ultimately decrease the delay of an endometriosis diagnosis in at-risk patients.

Role of ultrasonography in the diagnosis of endometriosis in infertile women: Ovarian endometrioma, deep endometriosis, and superficial endometriosis

Endometriosis is a complex chronic inflammatory process characterised by the presence of endometrial-like glandular tissue outside the uterine cavity, typically within the pelvic structures. This condition affects up to 10-15 % of women and those assigned female at birth, and can result in chronic pelvic pain and in/subfertility. Treatment goals include medical, surgical options and alternative therapies. Transvaginal ultrasound (TVUS) is the currently recommended first line investigation for endometriosis with magnetic resonance imaging (MRI) reserved for those with equivocal ultrasound findings. In this paper, we aim to outline the commonly seen sonographic appearances of endometriosis divided into anterior, middle and posterior pelvic compartments. Limitations to ultrasound imaging include high operator dependence and patient factors. New imaging techniques and research into the utility of artificial intelligence (AI) into the detection of endometriosis is currently underway, with possibility of reduced diagnostic delay and better patient outcomes.

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

Purpose

The 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.

Methods

A 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).

Results

The 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.

Discussion

This 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.

Conclusions

Endometriosis 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.

Superficial Endometriosis at Ultrasound Examination-A Diagnostic Criteria Proposal

The actual prevalence of superficial endometriosis is not known. However, it is considered the most common subtype of endometriosis. The diagnosis of superficial endometriosis remains difficult. In fact, little is known about the ultrasound features of superficial endometriotic lesions. In this study, we aimed to describe the appearance of superficial endometriosis lesions at ultrasound examination, with laparoscopic and/or histologic correlation. This is a prospective study on a series of 52 women with clinical suspicion of pelvic endometriosis who underwent preoperative transvaginal ultrasound and received a confirmed diagnosis of superficial endometriosis via laparoscopy. Women with ultrasound or laparoscopic findings of deep endometriosis were not included. We observed that superficial endometriotic lesions may appear as a solitary lesions, multiple separate lesions, and cluster lesions. The lesions may exhibit the presence of hypoechogenic associated tissue, hyperechoic foci, and/or velamentous (filmy) adhesions. The lesion may be convex, protruding from the peritoneal surface, or it may appear as a concave defect in the peritoneum. Most lesions exhibited several features. We conclude that transvaginal ultrasound may be useful for diagnosing superficial endometriosis, as these lesions may exhibit different ultrasound features.

Endometriosis: A multimodal imaging review

Endometriosis is a chronic inflammatory disorder characterized endometrial-like tissue present outside of the uterus, affecting approximately 10% of reproductive age women. It is associated with abdomino-pelvic pain, infertility and other non - gynecologic symptoms, making it a challenging diagnosis. Several guidelines have been developed by different international societies to diagnose and classify endometriosis, yet areas of controversy and uncertainty remains. Transvaginal ultrasound (TV-US) is the first-line imaging modality used to identify endometriosis due to its accessibility and cost-efficacy. Enhanced sonographic techniques are emerging as a dedicated technique to evaluate deep infiltrating endometriosis (DIE), depending on the expertise of the sonographer as well as the location of the lesions. MRI is an ideal complementary modality to ultrasonography for pre-operative planning as it allows for a larger field-of-view when required and it has high levels of reproducibility and tolerability. Typically, endometriotic lesions appear hypoechoic on ultrasonography. On MRI, classical features include DIE T2 hypointensity, endometrioma T2 hypointensity and T1 hyperintensity, while superficial peritoneal endometriosis (SPE) is described as a small focus of T1 hyperintensity. Imaging has become a critical tool in the diagnosis, surveillance and surgical planning of endometriosis. This literature review is based mostly on studies from the last two decades and aims to provide a detailed overview of the imaging features of endometriosis as well as the advances and usefulness of different imaging modalities for this condition.

Ultrasonographic Findings Indirectly Predicting Parametrial Involvement in Patients with Deep Endometriosis: The ULTRA-PARAMETRENDO I Study

STUDY OBJECTIVE

To evaluate ultrasonographic findings as a first-line imaging tool to indirectly predict the presence of parametrial endometriosis (PE) in women with suspected deep endometriosis (DE) undergoing surgery.

DESIGN

Retrospective analysis of a prospectively collected database (ULTRA-PARAMETRENDO I study; NCT05239871).

SETTING

Referral center for DE.

PATIENTS

Consecutive patients undergoing laparoscopic surgery for DE.

INTERVENTIONS

Preoperative transvaginal ultrasonography was done according to the International Deep Endometriosis Analysis consensus statement. A stepwise forward regression analysis was performed considering the simultaneous presence of DE nodules and the following ultrasonographic indirect signs of DE: diffuse adenomyosis, endometriomas, ovary fixed to the lateral pelvic wall or the uterine wall, absence of anterior/posterior sliding sign, and hydronephrosis. The gold standard for the presence of PE was surgery with histologic confirmation.

MEASUREMENTS AND MAIN RESULTS

Of 1079 patients, 212 had a surgical diagnosis of PE (left: 18.5%; right: 17.0%; bilateral: 15.9%). The obtained prediction model (χ² = 222.530; p <.001) for PE included, as independent indirect DE signs presence of hydronephrosis (odds ratio [OR] = 14.5; p = .002), complete absence of posterior sliding sign (OR = 3.3; p <.001), presence of multiple endometriomas per ovary (OR = 3.0; p = .001), and ovary fixation to the uterine wall (OR = 2.4; p <.001); as independent concomitant DE nodules, presence of uterosacral nodules with the largest diameter >10 mm (OR = 3.2; p <.001), presence of rectal endometriosis with the largest diameter >25 mm (OR = 2.3; p = .004), and rectovaginal septum infiltration (OR = 2.3; p = .003). The optimal diagnostic balance was obtained considering at least 2 concomitant DE nodules and at least 1 indirect DE sign (area under the curve 0.75; 95% confidence interval, 0.72-0.79).

CONCLUSION

Specific indirect ultrasonographic findings should raise suspicion of PE in women undergoing preoperative assessment for DE. The suspicion of parametrial invasion may be critical to address patients to expert leading centers, where proper diagnosis and surgical treatment for PE can be performed.

Advances in Imaging for Assessing Pelvic Endometriosis

In recent years, due to the development of standardized diagnostic protocols associated with an improvement in the associated technology, the diagnosis of pelvic endometriosis using imaging is becoming a reality. In particular, transvaginal ultrasound and magnetic resonance are today the two imaging techniques that can accurately identify the majority of the phenotypes of endometriosis. This review focuses not only on these most common imaging modalities but also on some additional radiological techniques that were proposed for rectosigmoid colon endometriosis, such as double-contrast barium enema, rectal endoscopic ultrasonography, multidetector computed tomography enema, computed tomography colonography and positron emission tomography-computed tomography with 16α-[18F]fluoro-17β-estradiol.

Strengths and limitations of diagnostic tools for endometriosis and relevance in diagnostic test accuracy research

Endometriosis is a chronic systemic disease that can cause pain, infertility and reduced quality of life. Diagnosing endometriosis remains challenging, which yields diagnostic delays for patients. Research on diagnostic test accuracy in endometriosis can be difficult due to verification bias, as not all patients with endometriosis undergo definitive diagnostic testing. The purpose of this State-of-the-Art Review is to provide a comprehensive update on the strengths and limitations of the diagnostic modalities used in endometriosis and discuss the relevance of diagnostic test accuracy research pertaining to each. We performed a comprehensive literature review of the following methods: clinical assessment including history and physical examination, biomarkers, diagnostic imaging, surgical diagnosis and histopathology. Our review suggests that, although non-invasive diagnostic methods, such as clinical assessment, ultrasound and magnetic resonance imaging, do not yet qualify formally as replacement tests for surgery in diagnosing all subtypes of endometriosis, they are likely to be appropriate for advanced stages of endometriosis. We also demonstrate in our review that all methods have strengths and limitations, leading to our conclusion that there should not be a single gold-standard diagnostic method for endometriosis, but rather, multiple accepted diagnostic methods appropriate for different circumstances. © 2022 International Society of Ultrasound in Obstetrics and Gynecology.

What is the accuracy of transvaginal ultrasound for endometriosis mapping prior to surgery when performed by a sonographer within an outpatient women's imaging centre?

INTRODUCTION

This study aimed to assess the accuracy of transvaginal ultrasound (TVUS) for the mapping of endometriosis before surgery when performed by sonographers in an outpatient women's imaging centre.

METHODS

A prospective longitudinal cohort study was performed. The study group comprised of 201 women who underwent a comprehensive TVUS assessment, performed by a sonographer. Laparoscopy was performed as the reference standard. Complete TVUS and surgical data were available for 53 women who were included in the final analysis.

RESULTS

Endometriosis was confirmed at a surgery in 50/53 (94.3%) participants, with 25/53 (47.2%) having deep endometriosis (DE) nodules and/or endometriomas present. TVUS for mapping of DE had an overall sensitivity of 84.0%, specificity of 89.3%, PPV of 87.5%, NPV of 86.2%, LR+ of 7.85, LR- of 0.18, and accuracy of 86.8% (P < 0.001). Ovarian immobility had poor sensitivity for detecting localised superficial endometriosis, DE, adhesions, and/or endometriomas (Left = 61.9% and right = 13.3%) but high specificities (left = 87.5% and right = 94.7%). Site-specific tenderness had low sensitivities and moderate specificities for the same. All soft markers of endometriosis failed to reach statistical significance except for left ovarian immobility (P = <0.001).

CONCLUSION

Sonographers well experienced in obstetric and gynaecological imaging, working in an outpatient women's imaging setting can accurately map DE; however, the performance of soft markers for detection of SE was poor.

Endometriosis at all ages: diagnostic ultrasound

Endometriosis is a gynecological disease affecting about 10% of the female population. The multifactorial hormonal, inflammatory, genetic, mental and behavior pathogenesis can result in chronic pelvic pain, blooding disorders and infertility causing disruption of quality of life. Correct diagnosis of the extension and topography is substantial in defining the adequate therapeutic strategy. In an increasing proportion of the cases, endometriosis is being managed medically and para-medically; diagnostic or therapeutic surgery can often be avoided or delayed. Transvaginal sonography is considered being the first-line imaging method in the diagnosis of pelvic endometriosis. The paradigm shift from the belief that endometriosis only affects women of reproductive age has drawn attention to endometriosis in both premenarchal and postmenopausal patients. This review resumes the actually recommended ultrasound signs in the case of patients in menstrual age. Specific diagnostic approaches in adolescent and menopausal patients are highlighted.

Ovarian Immobility at Transvaginal Ultrasound: An Important Sonographic Marker for Prediction of Need for Pelvic Sidewall Surgery in Women With Suspected Endometriosis

OBJECTIVES

To determine whether ovarian fixation at transvaginal ultrasound (TVU) is a marker for a need for laparoscopic pelvic sidewall surgery (ie, ureterolysis or dissection of adhesions involving the pelvic sidewall). The relationship between ovarian immobility at TVU with respect to endometriosis staging using the revised American Fertility Society (r-AFS) classification was also evaluated.

METHODS

Retrospective diagnostic accuracy study was performed in a tertiary referral hospital and two private hospitals. Sixty-six women with pelvic pain underwent detailed TVU preoperatively followed by laparoscopic endometriosis surgery. TVU ovarian mobility findings (ie, mobile versus fixed ovary) were compared to surgical findings, the need for laparoscopic pelvic sidewall surgery and r-AFS score (I-IV).

RESULTS

Complete ultrasound and surgical data were available for 66 of 77 (86%) women. Twenty-six of 66 (40%) had isolated superficial peritoneal endometriosis, 15 of 66 (23%) had ovarian endometrioma (OE), 13 of 66 (20%) had pelvic deep endometriosis (DE). Twenty-seven of 66 (41%) had ovarian fixation at TVU. The accuracy, sensitivity, specificity, positive predictive value, and negative predictive value of ovarian fixation at TVU for the prediction of need for laparoscopic pelvic sidewall surgery was 71%, 61%, 86%, 85%, and 62%, respectively (P = .0002). Ovarian fixation at TVU was significantly associated with the presence of ipsilateral OE, pouch of Douglas obliteration, pelvic DE nodules, and r-AFS stage III/IV (moderate/severe) endometriosis (all P-values <.05).

CONCLUSIONS

Ovarian fixation at TVU appears to be a marker for moderate/severe endometriosis and the need for laparoscopic pelvic sidewall surgery. This sign may be a valuable "red flag" for identifying women at increased risk of requiring an advanced laparoscopic surgeon, and in turn, improve surgical planning.

Hyaluronic acid gel application versus ovarian suspension for prevention of ovarian adhesions during laparoscopic surgery on endometrioma: a double-blind randomized clinical trial

Background

This study aimed to compare the effect of ovarian suspension and hyaluronic acid gel to prevent re-adhesions after laparoscopic endometrioma surgery.

Methods

This randomized clinical trial was conducted at Rasoul-e-Akram and Pars Hospitals, Tehran, Iran, 2016-18. Fifty patients with bilateral endometrioma and pelvic adhesions, the candidates of laparoscopic surgery, were included. In each patient, at the end of ovarian cystectomy and adhesiolysis, one of the ovaries was randomly sutured to the abdominal wall, and the HYAcorp Endogel covered the other; the adhesion rate was compared between the groups by ultrasonography, three-month after surgery.

Results

Mean age of patients was 32.6 years. Presurgical variables were similar between right and left ovaries and the study groups (P > 0.05). Postsurgical ultrasonography showed that ovarian soft markers, including < 1/3 ovarian adhesions (minimal adhesions) in 80.5% of ovaries of the Endogel group and 35.5% of the ovarian suspension group (P < 0.001) with higher ovarian mobility in the Endogel group (65% vs. 22%) (P = 0.001). In addition, site-specific tenderness and ovarian fading margin were lower in the Endogel group (P < 0.001).

Trial registration Clinical trial registry number: IRCT2015081723666N1, 12.19.2015, Date of registration: 01/02/2016; https://en.irct.ir/trial/20174?revision=20174. Date and number of IRB: 2015, I.R.IUMS.REC.1394.24703.

Conclusion

Hyaluronic acid gel can be more effective than ovarian suspension in preventing ovarian adhesions after laparoscopic treatment of endometriosis.

Sonographic features of endometriosis infiltrating the lateral parametrium

OBJECTIVE

Lateral parametrium endometriosis (LPE) can be associated with infiltration of ureters and hypogastric plexus, causing severe painful symptoms and functional impairment, and requiring complex and extensive surgery. The aim of this study was to evaluate the presentation of LPE lesions at transvaginal ultrasound, identifying sonographic features for disease recognition and mapping.

METHODS

This was a retrospective case-series of women with sonographic suspect of LPE confirmed at surgical exploration. We carried out a descriptive analysis of the ultrasound patterns of presentation and compared the features of the lesions according to their location cranially or caudally to the uterine artery.

RESULTS

Our population included 23 women, with a total of 26 parametrial lesions: all of them were hypoechoic, with absence of vascularization. Lesions lying above the uterine artery presented more frequently as ill-defined nodules (78.6 %, p < 0.01) and were associated with ipsilateral reduced or absent ovarian mobility (92.9 %, p < 0.01); the ones located below the uterine artery appeared more frequently as fan-shaped lesions with retraction of the surrounding tissues (83.3 %). Ureteral involvement was observed at surgery in 43.5 % of cases. In all patients, deep infiltrating endometriosis of the posterior compartment was observed: the utero-sacral ligaments were the most common location affected concurrently.

CONCLUSIONS

LPE may present at transvaginal sonography as hypoechoic, not vascularized lesions, most frequently with a nodular or with a fan-shaped appearance, respectively cranially or caudally to the uterine artery. Reduced ovarian sliding and ureteral involvement are commonly associated.

Endometriosis and the Urinary Tract: From Diagnosis to Surgical Treatment

We aim to describe the diagnosis and surgical management of urinary tract endometriosis (UTE). We detail current diagnostic tools, including advanced transvaginal ultrasound, magnetic resonance imaging, and surgical diagnostic tools such as cystourethroscopy. While discussing surgical treatment options, we emphasize the importance of an interdisciplinary team for complex cases that involve the urinary tract. While bladder deep endometriosis (DE) is more straightforward in its surgical treatment, ureteral DE requires a high level of surgical skill. Specialists should be aware of the important entity of UTE, due to the serious health implications for women. When UTE exists, it is important to work within an interdisciplinary radiological and surgical team.

SonoPODography: A new diagnostic technique for visualizing superficial endometriosis

OBJECTIVE

To perform a pilot diagnostic accuracy study of a novel transvaginal ultrasonography procedure called saline-infusion sonoPODography to predict superficial endometriosis in patients with suspected endometriosis.

STUDY DESIGN

A prospective single-center diagnostic accuracy study was performed from September 2019-November 2019. The index test sonoPODography was performed and the results were documented in a standardized fashion. SonoPODography was performed by installing saline into the pouch of Douglas (POD) via an intrauterine balloon catheter to create an acoustic window between the ultrasound probe and surrounding structures. The pelvis was then assessed for the presence or absence of superficial endometriosis using pre-defined features. Direct visualization at laparoscopy and histological assessment of excised endometriosis confirmed the outcome. The diagnostic performance of sonoPODography was evaluated.

RESULTS

42 consecutive participants underwent sonoPODography. Superficial endometriosis was identified by sonoPODography in 24/42 (57.1 %) and in 37/42 (88.1 %) participants by direct visualization at laparoscopy. The overall diagnostic performance of sonoPODography was: accuracy 69.1 %, sensitivity 64.9 %, specificity 100.0 %, positive predictive value 100.0 %, negative predictive value 27.8 %. Amongst those without deep endometriosis/endometriomas/pouch of Douglas obliteration, the diagnostic performance was: accuracy 80.0 %, sensitivity 77.7 %, specificity 100.0 %, positive predictive value 100.0 %, negative predictive value 33.3 %. The pouch of Douglas peritoneum was the most common site of superficial endometriosis.

CONCLUSIONS

SonoPODography is a novel ultrasound-based procedure that permits the direct visualization of superficial with respectable diagnostic accuracy. The findings of this pilot study are promising and justify the initiation of a larger outpatient study. SonoPODography may establish new avenues for the non-invasive diagnosis and investigation of endometriosis.

Anogenital distance in adult women is a strong marker of endometriosis: results of a prospective study with laparoscopic and histological findings

STUDY QUESTION

Could anogenital distance (AGD) be a non-invasive marker of endometriosis and correlated to the American Society for Reproductive Medicine revised score (r-ASRM) and ENZIAN classifications?

SUMMARY ANSWER

Surgically and histologically proven endometriosis is associated with a short AGD in women of reproductive age but not correlated either to the severity or to the location of the disease.

WHAT IS KNOWN ALREADY

AGD is a marker of intrauterine androgen exposure and exposure to oestrogen-like chemicals such as phthalates. Moreover, exposure to endocrine disruptors, such as organochlorine chemicals, is associated with endometriosis. It has been suggested that a short AGD in women is associated with an increased risk of endometriosis based on clinical and ultrasound exams.

STUDY DESIGN, SIZE, DURATION

A prospective cohort study was conducted from January 2018 to June 2019 in a tertiary-care centre including 168 adult women undergoing pelvic surgery.

PARTICIPANTS/MATERIALS, SETTING, METHODS

Of the 168 women included, 98 patients had endometriosis (endometriosis group) and 70 did not (non-endometriosis group). An operator (not the surgeon) measured the distance from the clitoral surface to the anus (AGD-AC) and from the posterior fourchette to the anus (AGD-AF) before surgery using a millimetre accuracy ruler. Endometriosis was diagnosed on exploration of the abdominopelvic cavity, and the r-ASRM and ENZIAN scores were calculated. All removed tissues underwent pathological examination.

MAIN RESULTS AND THE ROLE OF CHANCE

Mean (±SD) AGD-AF measurements were 21.5 mm (±6.4) and 32.3 mm (±8.1), and average AGD-AC measurements were 100.9 mm (±20.6) and 83.8 mm (±12.9) in the endometriosis and non-endometriosis groups (P < 0.001), respectively. Mean AGD-AF and AGD-AC measurements were not related to r-ASRM stage (P = 0.73 and 0.80, respectively) or ENZIAN score (P = 0.62 and 0.21, respectively). AGD-AF had a better predictive value than AGD-AC for discriminating the presence of endometriosis (AUC = 0.840 (95% CI 0.782–0.898) and 0.756 (95% CI 0.684–0.828)), respectively. For AGD-AF, an optimal cut-off of 20 mm had a specificity of 0.986 (95% CI 0.923–0.999), sensitivity of 0.306 (95% CI 26.1–31.6) and positive predictive value of 0.969 (95% CI 0.826–0.998). In multivariable analysis, the diagnosis of endometriosis was the only variable independently associated with the AGD-AF (β = −9.66 mm 95% CI −12.20–−7.12), P < 0.001).

LIMITATIONS, REASONS FOR CAUTION

The sample size was relatively small with a high proportion of patients with colorectal endometriosis reflecting the activity of an expert centre. Furthermore, we did not include adolescents and the AGD-AF measurement could be particularly relevant in this population.

WIDER IMPLICATIONS OF THE FINDINGS

The measurement of AGD could be a useful non-invasive tool to predict endometriosis. This could be especially relevant for adolescents and virgin women to avoid diagnostic laparoscopy and empiric treatment.

STUDY FUNDING/COMPETING INTEREST(S)

None.

Sonographer-acquired ultrasound protocol for deep endometriosis

Endovaginal sonographic imaging has been shown to reliably identify pelvic endometriosis, but most United States imaging practices do not adequately assess locations and features of endometriosis beyond ovarian endometrioma. In this article, we propose a protocol for sonographer-acquired images and maneuvers to be interpreted subsequently by sonologists (radiologists or gynecologists). The purpose is to improve the sensitivity of endovaginal sonography for the detection of endometriosis in imaging practices that involve the non-physician sonographer as part of their workflow.

A Multicenter International Temporal and External Validation Study of the Ultrasound-based Endometriosis Staging System

STUDY OBJECTIVE

The aim of this study was to validate temporally and externally the ultrasound-based endometriosis staging system (UBESS) to predict the level of complexity of laparoscopic surgery for endometriosis.

DESIGN

A multicenter, international, retrospective, diagnostic accuracy study was carried out between January 2016 and April 2018 on women with suspected pelvic endometriosis.

SETTING

Four different centers with advanced ultrasound and laparoscopic services were recruited (1 for temporal validation and 3 for external validation).

PATIENTS

Women with pelvic pain and suspected endometriosis.

INTERVENTIONS

All women underwent a systematic transvaginal ultrasound and were staged according to the UBESS system, followed by classification of laparoscopic level of complexity according to the Royal College of Obstetricians and Gynaecologists (RCOG) levels 1 to 3.

MEASUREMENTS AND MAIN RESULTS

UBESS I, II, and III were then correlated with RCOG levels 1, 2, and 3, respectively. A comparison between temporal and external sites (skipping "A") and between each site was performed in terms of the diagnostic accuracy of UBESS to predict RCOG laparoscopic skill level. A total of 317 consecutive women who underwent laparoscopy with suspected endometriosis were included. Complete transvaginal ultrasound and laparoscopic surgical outcomes were available for 293/317 (92.4%). At the temporal site, the accuracy, sensitivity, specificity, positive predictive value, negative predictive value, positive likelihood ratio, and negative likelihood ratio of UBESS I to predict RCOG level 1 were 80.0%,73.8%, 94.9%, 97.2%, 60.2%, 14.5%, and 0.3%, respectively; of UBESS II to predict RCOG level 2 were 81.0%, 70.6%, 82.0%, 26.7%, 96.8%, 3.9%, and 0.3%, respectively; of UBESS III to predict RCOG level 3 were 91.0%, 85.7%, 92.4%, 75.0%, 96.1%, 11.3%, and 0.2%, respectively. At the external sites, the results of UBESS I to predict RCOG level 1 were 90.3%, 92.0%, 88.4%, 90.2%, 90.5%, 7.9%, and 0.1% respectively; UBESS II to predict RCOG level 2 were 89.2%, 100.0%, 88.5%, 37.5%, 100.0%, 8.7%, and 0.0%, respectively; and UBESS III to predict RCOG level 3 were 86.0%, 67.6%, 98.2%, 96.2%, 82.1%, 37.8%, and 0.3%, respectively. When patients requiring ureterolysis (i.e., RCOG level 3) in the absence of bowel endometriosis were excluded (n = 54), the sensitivity of UBESS III to correctly classify RCOG level 3 increased from 85.7% to 96.7% at the temporal site (n = 42) and from 67.6% to 96.0% at the external sites (n = 12) (p <.005).

CONCLUSION

The results from this external validation study suggest that UBESS in its current form is not generalizable unless there is either or both bowel deep endometriosis and cul-de-sac obliteration present. The major limitation appears to be the misclassification of women who require surgical ureterolysis in the absence of bowel endometriosis.