Detection Of Anal Sphincter Defects Research Articles

Combined 3D Endoanal Ultrasound and Transperineal Ultrasound Improves the Detection of Anal Sphincter Defects.

Anal sphincter injury, mainly due to obstetric or iatrogenic etiology, is the most common cause of fecal incontinence (FI). Three-dimensional endoanal ultrasound (3D EAUS) is used for assessment of the integrity and the degree of anal muscle injury. However, 3D EAUS accuracy may be hampered by regional acoustic effects, such as intravaginal air. Therefore, our aim was to examine whether a combination of transperineal ultrasound (TPUS) and 3D EAUS would improve the accuracy of detection of anal sphincter injury. We prospectively performed 3D EAUS followed by TPUS in every patient evaluated for FI in our clinic between January 2020 and January 2021. The diagnosis of anal muscle defects was assessed in each ultrasound technique by two experienced observers that were blinded to each other's assessments. Interobserver agreement for the results of the 3D EAUS and the TPUS exams was examined. A final diagnosis of anal sphincter defect was based on the results of both ultrasound methods. Discordant results were re-analyzed by the two ultrasonographers for a final consensus on the presence or absence of defects. A total of 108 patients underwent ultrasonographic assessment due to FI (mean age 69 ± 13). Interobserver agreement for the diagnosis of tear on EAUS and TPUS was high (83%) with Cohen's kappa of 0.62. EAUS confirmed anal muscle defects in 56 patients (52%), while TPUS confirmed them in 62 patients (57%). The final consensus agreed on the diagnosis of 63 (58%) muscular defects and 45 (42%) normal exams. The Cohen's kappa coefficient of agreement between the results of the 3D EAUS and the final consensus was 0.63. The combination of 3D EAUS and TPUS improved the detection of anal muscular defects. The application of both techniques for the assessment of the anal integrity should be considered in every patient going through ultrasonographic assessment for anal muscular injury.

Comparing the diagnostic accuracy of 3 ultrasound modalities for diagnosing obstetric anal sphincter injuries

The optimal imaging modality of obstetric anal sphincter injuries needs to take into consideration convenience, availability, and ability to assess the sphincter morphologic condition. Endoanal ultrasound imaging currently is regarded as the reference standard, but it is not widely available in obstetric units. Exoanal alternatives exist, such as 3-dimensional introital or transperineal ultrasound imaging, which are already readily available in most obstetrics and gynecology units. The primary objective was to evaluate the diagnostic accuracy of 3-dimensional introital and 3-dimensional transperineal ultrasound imaging compared with 3-dimensional endoanal ultrasound imaging as the reference standard for the detection of anal sphincter defects in women who sustained obstetric anal sphincter injuries. The secondary objective was to correlate a diagnosis of anal sphincter defect on imaging to symptoms of anal incontinence, and to assess patient discomfort that is experienced for each imaging modality. A cross-sectional study was conducted of 250 women who sustained obstetric anal sphincter injuries, all of whom underwent 3-dimensional introital, transperineal, and endoanal ultrasound imaging. Introital and transperineal ultrasound imaging were assessed with tomographic ultrasound imaging. All of the women completed a validated modified St Mark's Score and Visual Analogue Score for discomfort. Optimal cut-off values for a significant defect on tomographic ultrasound imaging were defined as those with the greatest sensitivity and specificity based on receiver operating characteristic curves with endoanal ultrasound imaging as the reference standard. Diagnostic test characteristics of introital and transperineal ultrasound imaging were calculated with the use of these optimal cut-offs. Optimal cut-off for a significant external anal sphincter defect was ≥3 of 7 slices; sensitivity and specificity were 0.65 and 0.75 on introital imaging and 0.70 and 0.69 on transperineal ultrasound imaging. Optimal cut-off for a significant internal anal sphincter defect was ≥2 of 5 slices; sensitivity and specificity were 0.59 and 0.84 on introital imaging and 0.43 and 0.97 on transperineal ultrasound imaging. The area under the curve for the diagnosis of external and internal anal sphincter defects ranged from 0.70-0.74 (P<.001) for introital and transperineal imaging. Positive predictive value for external and internal sphincter defects ranged from 0.37-0.63, and negative predictive value ranged from 0.85-0.93 for introital and transperineal ultrasound imaging. Endoanal ultrasound imaging was the only modality for a defect to correlate with symptoms; mean modified St. Mark's score for a defect sphincter was 2.4 (standard deviation, 4.1) and for an intact sphincter was 0.9 (standard deviation, 2.7; P<.01). Introital and transperineal ultrasound imaging were associated with less discomfort than endoanal ultrasound imaging. Endoanal ultrasound imaging remains the most accurate diagnostic imaging modality. With low positive predictive values, introital and transperineal ultrasound imaging are not suitable for the identification of sphincter defects; however, high negative predictive values show a good ability to detect an intact sphincter. The optimal cut-off number of slices on tomographic ultrasound imaging for external and internal anal sphincters allows for standardization of a significant defect. In women with a history of obstetric anal sphincter injuries, introital and transperineal ultrasound imagings are suitable to screen for an intact sphincter if endoanal ultrasound imaging is not available. When defects are found, women should then have endoanal ultrasound imaging to verify the diagnosis.

Detection of Anal Sphincter Defects in Female Patients With Fecal Incontinence

Endoanal ultrasound is widely used for the detection of external and internal anal sphincter defects in patients with fecal incontinence. Recently, 3-dimensional transperineal ultrasound has been introduced as a noninvasive imaging method for the detection of these sphincter defects. This study was designed to assess agreement between 3-dimensional transperineal ultrasound and 2-dimensional endoanal ultrasound regarding the detection of anal sphincter defects in women with fecal incontinence. This study was designed as a prospective observational study. The study took place in a university hospital. Between October 2008 and June 2009, all women with concerns of fecal incontinence underwent 2-dimensional endoanal ultrasound as well as 3-dimensional transperineal ultrasound. The main outcome measures are the presence of external and internal anal sphincter defects. Fifty-five patients were included. External and internal anal sphincter defects were observed with 2-dimensional endoanal ultrasound in 27 (49%) and 15 (27%) patients. Three-dimensional transperineal ultrasound detected an external and internal sphincter defect in 19 (35%) and 16 (29%) patients. The Cohen κ coefficient for the detection of external (κ = 0.63) and internal (κ = 0.78) anal sphincter defects was good. This study's limitations include the absence of a surgical examination as the reference standard in the determination of sphincter defects. This study shows good agreement between 3-dimensional transperineal ultrasound and 2-dimensional endoanal ultrasound regarding the detection of anal sphincter defects. Based on these data, 3-dimensional transperineal ultrasound might be considered as a valuable alternative noninvasive investigation method.

The diagnostic accuracy of endovaginal and transperineal ultrasound for detecting anal sphincter defects: The PREDICT study

To determine the accuracy and predictive value of transperineal (TPU) and endovaginal ultrasound (EVU) in the detection of anal sphincter defects in women with obstetric anal sphincter injuries and/or postpartum symptoms of faecal incontinence. One hundred and sixty-five women were recruited, four women were excluded as they were seen years after their last delivery. TPU and EVU, followed by endonanal ultrasound (EAU), were performed using the B&K Viking 2400 scanner. Sensitivity and specificity, as well as predictive values with 95% confidence intervals, for detecting anal sphincter defects were calculated for EVU and TPU, using EAU as the reference standard. On EAU a defect was found in 42 (26%) women: 39 (93%) had an external (EAS) and 23 (55%) an internal anal sphincter (IAS) defect. Analysable images of one level of the EAS combined with an analysable IAS were available in 140 (87%) women for EVU and in 131 (81%) for TPU. The sensitivity and specificity for the detection of any defect was 48% (30-67%) and 85% (77-91%) for EVU and 64% (44-81%) and 85% (77-91%) for TPU, respectively. Although EAU using a rotating endoprobe is the validated reference standard in the identification of anal sphincter defects, it is not universally available. However while TPU and/or EVU with conventional ultrasound probes can be useful in identifying normality, for clinical purposes they are not sensitive enough to identify an underlying sphincter defect.

Imaging of the posterior pelvic floor.

Disorders of the posterior pelvic floor are relatively common. The role of imaging in this field is increasing, especially in constipation, prolapse and anal incontinence, and currently imaging is an integral part of the investigation of these pelvic floor disorders. Evacuation proctography provides both structural and functional information for rectal voiding and prolapse. Dynamic MRI may be a valuable alternative as the pelvic floor muscles are visualised, and it is currently under evaluation. Endoluminal imaging is important in the management of anal incontinence. Both endosonography and endoanal MRI can be used for detection of anal sphincter defects. Endoanal MRI has the advantage of simultaneously evaluating external sphincter atrophy, which is an important predictive factor for the outcome of sphincter repair. Many aspects of constipation and prolapse remain incompletely understood and treatment is partly empirical; however, imaging has a central role in management to place patients into treatment-defined groups.