Ultrasonography for bowel endometriosis

Ultrasound Diagnosis of Bowel Endometriosis

BACKGROUND

Bowel endometriosis is one of the more severe manifestations of deep endometriosis; it may cause pain and intestinal symptoms. The noninvasive diagnosis of bowel endometriosis is of crucial importance in planning the management of patients affected by this condition.

OBJECTIVES

This review aims to describe how transvaginal ultrasonography (TVS) is performed in patients with suspicion of rectosigmoid endometriosis, the diagnostic performance, and the strengths and limitations of this technique.

METHODS

To identify relevant literature, a literature search was performed across the PubMed and Google Scholar databases up to July 2024.

OUTCOME

Numerous meta-analyses have demonstrated that TVS has high diagnostic accuracy in diagnosing rectosigmoid endometriosis. Rectosigmoid nodules can present with different morphological characteristics, but they are typically described as irregular, hypoechoic nodules located in the anterior wall of the rectosigmoid colon. The presence of "soft markers," such as a negative sliding sign and kissing ovaries, can further reinforce the diagnosis of this condition. Posterolateral parametrial involvement often coexists with large rectal nodules. Introducing water contrast into the rectosigmoid does not improve the performance of TVS in diagnosing rectosigmoid endometriosis.

CONCLUSIONS AND OUTLOOK

TVS should be the first-line investigation in women suspected of having rectosigmoid endometriosis. The widespread use of TVS for the diagnosis of intestinal endometriosis can reduce diagnostic delays and facilitate the treatment of patients affected by this condition.

ACR Appropriateness Criteria® Endometriosis

Endometriosis is a common condition impacting individuals assigned female at birth. Though incompletely understood, the disorder is caused by endometrial-like tissue located outside of the endometrial cavity, associated with inflammation and fibrosis. Clinical presentation is variable, ranging from asymptomatic to severe pelvic pain and infertility. Treatment is determined by the patient's individualized goals and can include medical therapies to temporize symptoms or definitive surgical excision. Imaging is used to help diagnose endometriosis and for treatment planning. The American College of Radiology Appropriateness Criteria are evidence-based guidelines for specific clinical conditions that are reviewed annually by a multidisciplinary expert panel. The guideline development and revision process support the systematic analysis of the medical literature from peer reviewed journals. Established methodology principles such as Grading of Recommendations Assessment, Development, and Evaluation or GRADE are adapted to evaluate the evidence. The RAND/UCLA Appropriateness Method User Manual provides the methodology to determine the appropriateness of imaging and treatment procedures for specific clinical scenarios. In those instances where peer reviewed literature is lacking or equivocal, experts may be the primary evidentiary source available to formulate a recommendation.

Ultrasonographic characterization of parametrial endometriosis: a prospective study

OBJECTIVE

To study the ultrasonographic diagnostic accuracy and characteristics of parametrial endometriosis comprehensively.

DESIGN

This prospective study enrolled patients with suspected deep endometriosis (DE) scheduled for laparoscopic surgical treatment. Preoperative ultrasonographic examinations were performed following the International Deep Endometriosis Analysis criteria. This study aimed to evaluate the presence of parametrial endometriosis and its ultrasonographic characteristics, using surgical diagnosis as the reference standard. Additionally, indirect signs of DE and concomitant DE nodules associated with parametrial involvement were identified, assessing their predictive significance in the anterior, lateral, and posterior parametrial areas.

SETTING

Referral institution for endometriosis.

PATIENTS

Patients with suspected DE scheduled for surgical treatment.

INTERVENTIONS

Standardized preoperative ultrasonographic examination.

MAIN OUTCOME MEASURES

The diagnostic accuracy of transvaginal ultrasound in identifying parametrial endometriosis, including sensitivity and specificity, and the ultrasonographic characteristics of parametrial nodules, prevalence in distinct parametrial areas, and associations with indirect DE signs and concomitant DE nodules.

RESULTS

Surgical confirmation of parametrial nodules was observed in 105 of 545 patients (left, 18.5; right, 17.0%). Transvaginal ultrasound demonstrated a sensitivity of 77.1% (95% confidence interval, 68.0%-84.8%) and specificity of 99.1% (95% confidence interval, 67.7%-99.8%). Parametrial nodules typically exhibited characteristics such as a mild hypoechoic appearance (83.6%), starry morphology (74.7%), irregular margins (70.2%), and low vascularization. The posterior parametrial region was the most common location (52.2%), followed by the lateral (41.0%) and anterior (6.8%) parametrial regions. Concomitant DE nodules in the rectum (63.5%) and infiltrating the rectovaginal septum (56.5%) were significantly more prevalent in patients with parametrial involvement. Indirect DE signs, such as the ovaries fixed to the uterine wall (71.8%) and the absence of a posterior sliding sign (51.8%), were also more common in women with parametrial nodules. Hydronephrosis, although relatively uncommon in patients with parametrial involvement (8.2%), was largely detected in lateral parametrial nodules (70.0%).

CONCLUSIONS

This study represents a systematic ultrasonographic characterization of parametrial endometriosis. Specifically, it comprehensively assesses the diagnostic accuracy of transvaginal ultrasound in identifying parametrial involvement within a sizable cohort of patients with preoperative suspicion of DE.

CLINICAL TRIAL REGISTRATION NUMBER

NCT06017531.

"From the tip to the deep of the iceberg": Parametrial involvement in endometriosis

Deep endometriosis (DE) can be localized in the parametrium, a complex bilateral anatomical structure, sometimes necessitating intricate surgical intervention due to the potential involvement of autonomic nerves, uterine artery, and ureter. If endometriotic ovarian cysts have been considered metaphorically representative of "the tip of the iceberg" concerning concealed DE lesions, it is reasonable to assert that parametrial lesions should be construed as the most profound region of this iceberg. Also, based on a subdual clinical presentation, a comprehensive diagnostic parametrial evaluation becomes imperative to strategize optimal management for patients with suspected DE. Recently, the ULTRAPARAMETRENDO studies aimed to evaluate the role of transvaginal ultrasound for parametrial endometriosis, showing distinctive features, such as a mild hypoechoic appearance, starry morphology, irregular margins, and limited vascularization. The impact of medical therapy on parametrial lesions has not been described in the current literature, primarily due to the lack of adequate detection at imaging. The extension of DE into the parametrium poses significant challenges during the surgical approach, thereby increasing the risk of intra- and postoperative complications, mainly if performed by centers with low expertise and following multiple surgical procedures where parametrial involvement has gone unrecognized. Over time, the principles of nerve-sparing surgery have been incorporated into the surgical DE treatment to minimize iatrogenic damage and potentially reduce the risk of functional complications.

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.

Diagnostic accuracy of the IDEA protocol for non invasive diagnosis of rectosigmoid DE - a prospective cohort study

OBJECTIVES

 To test the accuracy of TVS applying the IDEA approach for suspected rectosigmoid DE and to determine the frequency of other pelvic diseases mimicking DE in patients undergoing surgery.

MATERIALS UND METHODS

 Prospective single center observational study including consecutive women undergoing TVS for clinically suspected rectosigmoid DE followed by conservative or surgical therapy. TVS findings were compared with those obtained by laparoscopy and confirmed histologically.

RESULTS

 Of the 671 included patients, 128 women opted for medical therapy, and 6 patients decided for surgery but did not give consent to participate in the study. 537 women were enrolled in the final analysis. 279 (52 %) exhibited surgically confirmed rectosigmoid DE. The sensitivity and specificity, positive and negative predictive value (PPV, NPV), positive and negative likelihood ratio (LR+/-) and accuracy of TVS for diagnosing DE in the rectosigmoid were 93.5 %, 94.6 %, 94.9 %, 93.1 %, 17.24, 0.07, 94.04 %. 12 women who were clinically suspected for DE and mimicked sonographic signs fulfilling the IDEA criteria did exhibit other pathologies. Diagnoses were as follows: vaginal Gartner duct cyst (3/291;1.0 %), anorectal abscess (3/291; 1.0 %), rectal cancer (2/291;0.7 %), hydrosalpinx (2/291;0.7 %), metastatic endometrial cancer (1/291;0.35 %) and Crohn's disease (1/291;0.35 %).

CONCLUSION

 TVS for diagnosing colorectal DE applying the IDEA criteria is highly accurate for presurgical diagnosis. However, additional pelvic pathologies are encountered in 4-5 % of women attending for suspected rectosigmoid DE. These need to be taken into account when investigating patients for suspected DE.

Ultrasound-guided Aspiration Combined with Medical Treatment for an Unexpected Rectal Endometriotic Cyst: A Case Report

Most bowel endometriotic lesions are ill-defined serosal and subserosal nodules, and no case of cystic bowel endometriosis has been reported in the literature. This is the first report of an unexpected presentation of bowel endometriosis as a primary cyst located inside the posterior rectal wall. The patient was a 26-year-old nulliparous woman with progressive lower abdominal pain for 6 days and difficult defecation for 1 day. Colorectal surgeons recommended bowel resection owing to the giant rectal mass. However, the patient refused to undergo surgery. Ultrasound-guided aspiration of the rectal endometriotic cyst followed by gonadotropin-releasing hormone agonist injection was individually scheduled, which finally brought significant improvement both in symptoms and in the size of the rectal endometriotic lesion.

Acute abdominal pain in women of reproductive age: keys to suggest a complication of endometriosis

Although endometriosis is a common gynecological condition in women of reproductive age, a complication of endometriosis is rarely considered as the differential diagnosis of acute abdominal pain in that context. However, acute events in women with endometriosis can represent life-threatening conditions, which require emergent treatment and often surgical management. Mass effect of endometriotic implants can give rise to obstructive complications, specifically occurring in the bowel or in the urinary tract, while inflammatory mediators released by ectopic endometrial tissue can lead to inflammation of the surrounding tissues or to superinfection of the endometriotic implants. Magnetic resonance imaging is the best imaging modality to reach the diagnosis of endometriosis, but an accurate diagnosis is possible on computed tomography, especially in the presence of stellar, mildly enhanced, infiltrative lesions in suggestive areas. The aim of this pictorial review is to provide an image-based overview of key findings for the diagnosis of acute abdominal complications of endometriosis.

Malignant transformation of rectal endometriosis: Preoperative diagnosis by endorectal ultrasound guided biopsy

The prevalence of malignant transformation of endometriotic lesions is estimated between 0.3% and 1%. Malignant transformations of endometriosis occur in the colorectum is rarer, accounting for 0.25%. Because the malignant transformation of colorectal endometriosis rarely involves mucosa, it is difficult to obtain abnormal tissue by routine endoscopic biopsy. In this case, we evaluated a patient with a rectal mass by endorectal ultrasound (ERUS) and performed endorectal ultrasound-guided biopsy (EGB). Malignant transformations of endometriosis were confirmed by histological result. For patients with rectal tumors but with negative findings on colonoscopy and biopsy, ERUS and EGB contribute to preoperative diagnosis.

Acute endometriosis-related sigmoid perforation in pregnancy- case report

Background

An acute abdomen is an emergency that requires accurate diagnosis and prompt treatment. In pregnancy, the process is even more challenging and sometimes the radiological findings are unclear. Moreover, endometriosis- related complications are rare, especially in previously unknown endometriosis.

Case presentation

We report on a case of acute endometriosis-related sigmoid perforation during pregnancy (34 weeks of gestation) due to a previously unknown deep intestinal infiltrating endometriosis with focal ulceration of the affected colonic mucosa.

Conclusions

Despite the low relative risk, clinicians should be aware of possible endometriosis-associated complications in pregnancy with potentially life-threatening events, even in previously unknown endometriosis. Further studies should evaluate intestinal complications during pregnancy in relation to previous treatment of intestinal endometriosis (conservative vs. surgical).

Endometriosis and preterm birth: A Danish cohort study

INTRODUCTION

Emerging evidence shows that women with endometriosis face a higher risk of preterm birth. However, the pathways are unclear. The objective of this study is to further investigate at different gestational ages the association between endometriosis and different pathways of preterm birth including, medically indicated preterm birth, premature pre-labor rupture of membranes (PPROM), and spontaneous labor contractions.

MATERIAL AND METHODS

In this population-based cohort study we linked singleton pregnancies from the Aarhus Birth Cohort to the Danish National Patient Registry, the Danish Medical Birth Registry, the Danish National Pathology Registry and Data Bank, and the Danish in vitro fertilization registry to gather information on endometriosis status, outcomes and maternal characteristics. We investigated preterm birth before 37 completed weeks of gestation and very preterm birth before 32 completed weeks of gestation. We explored different pathways including medically indicated preterm birth defined as induction of labor with intact membranes and no prior labor contractions, PPROM defined as rupture of membranes, and spontaneous labor contractions defined as contractions with intact membranes resulting in labor.

RESULTS

We found that women with endometriosis had an increased risk of preterm birth before 37 gestational weeks overall (adjusted hazard rate [aHR] 1.6, 95% confidence interval [CI] 1.3-1.9) and very preterm birth before 32 gestational weeks (aHR 1.8, 95% CI 1.1-2.9) compared with women without endometriosis. Medically indicated preterm birth was more prominent in women with endometriosis in deliveries before 37 gestational weeks (aHR 2.4, 95% CI 1.8-3.2) whereas spontaneous labor contractions were more common before 32 gestational weeks (aHR 2.2, 95% CI 1.1-4.5) in women with endometriosis compared with women without endometriosis. Further, in the analyses restricted to women with a histologically verified diagnosis of endometriosis, the results were strengthened overall and showed that women with endometriosis had an increased risk of PPROM before 32 gestational weeks (aHR 3.49, 95% CI1.36-8.98).

CONCLUSIONS

Endometriosis was associated with both preterm and very preterm birth; however, apparently through different pathways. Women with endometriosis were more prone to have medically indicated preterm births before 37 gestational weeks and spontaneous preterm births before 32 gestational weeks compared with women without endometriosis.

Diagnostic delay of endometriosis in adults and adolescence-current stage of knowledge

PURPOSE

The purpose of this article is to provide a modern perspective on the diagnosis of endometriosis with particular attention to the role of ultrasound examination. In the present study, we highlight the problem of endometriosis in teenage girls and discuss the patients' perspective on the diagnostic process.

METHODS

In order to present the most recent reports on the diagnosis of endometriosis, the PubMed database was searched. Articles published within the last 3 years (2019-2021) and those considered relevant during the bibliographic review were analyzed.

RESULTS

The role of ultrasound examination and assessment of patients' perspective related to delayed and incorrect diagnosis were considered to be the most important in the recent reports. Attention was also paid to the problem of endometriosis diagnosis in adolescent girls.

CONCLUSIONS

Appropriately constructed and used questionnaires help to determine the risk of endometriosis in a particular patient. The primary method for diagnosis is extended ultrasound examination, which should be performed especially in patients with a high risk of developing the disease. This procedure is applicable to both adult and adolescent women. Awareness of the possibility of developing the disease in a particular patient, combined with appropriate use of ultrasound examination, can contribute to the decrease in diagnostic delay.

A prospective study comparing rectal water contrast-transvaginal ultrasonography with sonovaginography for the diagnosis of deep posterior endometriosis

INTRODUCTION

Preoperative assessment of deep endometriotic (DE) nodules is necessary to inform patients about the possible treatments and provide informed consent in case of surgery. This study aims to investigate the diagnostic performance of rectal water-contrast transvaginal ultrasonography (RWC-TVS) and sonovaginography (SVG) in women with suspicion of posterior DE.

MATERIAL AND METHODS

This prospective comparative study (NCT04296760) enrolled women with clinical suspicion of DE at our institution (Piazza della Vittoria 14 SRL, Genoa, Italy). Exclusion criteria were previous diagnosis of DE by imaging techniques or laparoscopy. All patients underwent RWC-TVS and SVG, independently performed by two gynecological sonologists blinded to the other technique's results. Patients underwent laparoscopic surgery within the following three months; imaging findings were compared with surgical and histological results.

RESULTS

In 208 of 281 (74.0%) patients included, posterior DE was surgically confirmed in rectosigmoid (n = 88), vagina (n = 21), rectovaginal septum (n = 34) and uterosacral ligaments (n = 156). RWC-TVS and SVG demonstrated similar sensitivity (SE; 93.8% vs 89.4%; p = 0.210) and specificity (SP; 86.3% vs 79.4%; p = 0.481) in diagnosing posterior DE. Specifically, both examinations had similar accuracy in detecting nodules of uterosacral ligaments (p = 0.779), vagina (p = 0.688) and rectovaginal septum (p = 0.824). RWC-TVS had higher SE (95.2% vs 82.0%; p = 0.003) and similar SP (99.5% vs 98.5%; p = 0.500) in diagnosing rectosigmoid endometriosis and estimated better infiltration of intestinal submucosa (p = 0.039), and distance between these nodules and anal verge (p < 0.001); only RWC-TVS allowed the estimation of bowel lumen stenosis. A similar proportion of discomfort was experienced during both examinations (p = 0.191), although a statistically higher mean visual analog score was reported during RWC-TVS (p < 0.001).

CONCLUSIONS

Although RWC-TVS and SVG have similar accuracy in the diagnosis of DE, RWC-TVS performed better in assessment of the characteristics of rectosigmoid endometriosis.

Ultrasonographic 3D Evaluation in the Diagnosis of Bladder Endometriosis: A Prospective Comparative Diagnostic Accuracy Study

OBJECTIVE

The use of three-dimensional (3D) transvaginal ultrasonography (TVS) has been investigated for the diagnosis of deep endometriosis (DE). This study aimed to evaluate if 3D reconstructions improve the performance of TVS) in assessing the presence and characteristics of bladder endometriosis (BE).

DESIGN

This was a single-center comparative diagnostic accuracy study. Participants/Materials, Setting, Methods: Patients referred to our institution (Piazza della Vittoria 14 Srl, Genova, Italy) with clinical suspicion of DE were included. In case of surgery, women underwent systematic preoperative ultrasonographic imaging; an experienced sonographer performed a conventional TVS; another experienced sonographer, blinded to results of the previous exam, performed TVS, with the addition of 3D modality. The presence and characteristics of BE nodules were described in accord with International DE Analysis group consensus. Ultrasound data were compared with surgical and histological results.

RESULTS

Overall, BE was intraoperatively found in 34 out of 194 women who underwent surgery for DE (17.5%; 95% confidence interval: 12.8-23.5%). TVS without and with 3D reconstructions were able to detect endometriotic BE in 82.2% (n = 28/34) and 85.3% (n = 29/34) of the cases (p = 0.125). Both the exams similarly estimated the largest diameter of BE (p = 0.652) and the distance between the endometriotic nodule and the closest ureteral meatus (p = 0.341). However, TVS with 3D reconstructions was more precise in estimating the volume of BE (p = 0.031). In one case (2.9%), TVS without and with 3D reconstructions detected the infiltration of the intramural ureter, which was confirmed at surgery and required laparoscopic ureterovesical reimplantation.

LIMITATIONS

The extensive experience of the gynecologists performing the ultrasonographic scans, the lack of prestudy power analysis, and the population selected, which may have been influenced by the position of the institution as a referral center specialized in the treatment of severe endometriosis, are limitations of the current study.

CONCLUSION

Our results demonstrated the high accuracy of ultrasound for diagnosing BE. The addition of 3D reconstructions does not improve the performance of TVS in diagnosing the presence and characteristics of BE. However, the volume of BE may be more precisely assessed by 3D ultrasound.

Advances in the medical management of bowel endometriosis

Endometriosis infiltrating the bowel can be treated medically in accurately selected women not seeking conception and without overt obstructive symptomatology. When the rectosigmoid junction is involved, the probabilities of intestinal symptoms relief, undergoing surgery after treatment failure, and developing bowel obstruction during hormonal treatment are around 70%, 10%, and 1-2%, respectively. When the lesion infiltrates exclusively the mid-rectum, thus in cases of true rectovaginal endometriosis, the probabilities of intestinal symptoms relief and undergoing surgery are about 80% and 3%, respectively. Endometriotic obstructions of the rectal ampulla have not been reported. A rectosigmoidoscopy or colonoscopy should be performed systematically before starting medical therapies, also to rule out malignant tumours arising from the intestinal mucosa. Progestogens are safe, generally effective, well-tolerated, inexpensive, and should be considered as first-line medications for bowel endometriosis. Independently of symptom relief, intestinal lesions should be checked periodically to exclude nodule progression during hormonal treatment.