Postpartum two- and three-dimensional ultrasound evaluation of anal sphincter complex in women with obstetric anal sphincter injury

Three-Dimensional Transperineal Ultrasound Guiding Early Secondary Repair of Obstetric Anal Sphincter Injury in an Incontinent Patient without Suture Dehiscence

We present the case of a 36-year-old primigravida who gave birth to a 3200 g baby by vacuum-assisted (Kiwi OmniCup™) operative vaginal delivery with mediolateral episiotomy. A "y"-shaped perineal tear with a grade IIIC obstetric anal sphincter injury (OASI) was diagnosed and repaired. Two days after delivery, in the absence of suture dehiscence, she started experiencing complete anal incontinence. A decision was made in association with a proctologic surgeon for an early secondary repair. Before surgery, a Three-dimensional transperineal ultrasound (TPUS) was performed. The exam revealed a major defect of the external anal sphincter at the 11 o'clock position. This allowed for the reopening of only a circumscribed area of the perineal suture and repair of the sphincters using the end-to-end technique. The symptoms regressed completely, and follow-up TPUS demonstrated the gradual wound healing process. Anal incontinence, secondary to obstetric anal sphincter injury (OASI), has a severe negative impact on women's quality of life. TPUS is an effective method to detect sphincter defects and monitor the healing process. This report investigates the feasibility of identifying the sphincter tear in an incontinent puerperal patient without suture dehiscence in order to target early secondary repair while minimizing its extent. TPUS has proven a safe and effective tool to guide early secondary repair of symptomatic OASI complications while minimizing the invasiveness of the procedure. Multidisciplinary management is crucial to ensure the adequate standard of care.

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

INTRODUCTION

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.

METHODS

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.

RESULTS

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.

CONCLUSIONS

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.

Morphological differences in the female anal sphincter complex between endoanal and exoanal ultrasound

INTRODUCTION AND HYPOTHESIS

This study was aimed at describing the morphological characteristics of the normal female anal sphincter complex (ASC) by high-resolution transperineal ultrasound (TPUS) and endoanal ultrasound (EAUS).

METHODS

Thirty volunteers, including 19 nulliparous and 11 women who had only given birth by Cesarean section, were recruited. The ASC was shown in a set of five slices by EAUS and 8 slices by TPUS. EAUS slices 1 and 5 matched TPUS slices 1 and 8; EAUS slices 2, 3, and 4 were approximately at the levels of TPUS slices 3, 5, and 7. The anterior and lateral EAS and IAS thicknesses were measured and the two methods were compared.

RESULTS

The median age was 29 years. The mean body mass index (BMI) was 20.6 kg/m². All measured values obtained by TPUS were normally distributed. The EAS thickness on EAUS slice 2 and the IAS thickness on EAUS slices 2 and 3 were not normally distributed. The mean anterior EAS thickness was 2.51 mm, 2.96 mm, and 3.53 mm in slices 3, 5, and 7 on TPUS and was significantly thinner than that in slices 2 (2.62 mm), 3 (3.77 mm), and 4 (4.62 mm) on EAUS. In contrast, the IAS was markedly thicker on TPUS. The ratio of sphincter thickness anteriorly to laterally was similar using the two methods.

CONCLUSIONS

The morphological characteristics of EAS shown by TPUS and EAUS were similar. EAS was thinner, and IAS was thicker on TPUS. The IAS seems to be distorted on endoanal imaging.

Use of endoanal ultrasound in detecting obstetric anal sphincter injury immediately after birth

INTRODUCTION

Obstetric anal sphincter injury (OASI) complicates around 5% of deliveries in primiparas. The study objective was to assess the utility of three-dimensional endoanal ultrasonography (3D-EAUS) in the diagnosis of OASI.

MATERIAL AND METHODS

The present study was designed to mirror screening settings with an unselected cohort of nulliparous women. All enrolled patients underwent clinical examination of the perineum by the caregiver, and 3D-EAUS was conducted. Post-processing of ultrasonography volume data was performed by an experienced colorectal surgeon who was blinded to all other data. The sensitivity, specificity, negative predictive value, and positive predictive value of 3D-EAUS in the diagnosis of OASI was evaluated. The trial is registered at ISCRTN: 18006769.

RESULTS

A total of 680 scans were performed, of which 18.5% were judged as "non-assessable", resulting in 554 assessable recordings. Sphincter defects were observed in 12.8% of all assessable recordings on 3D-EAUS (n = 71). With clinical examination set as the reference standard, ultrasound sensitivity in the diagnosis of OASI was 30.4%, whereas its specificity was 87.9%. The negative predictive value was 96.7% and the positive predictive value was only 9.9%. Comments were left on 175 examinations, of which 74% referred to the management of the examination.

CONCLUSIONS

Using 3D-EAUS in a maternity ward is demanding because staff generally have little experience in endoanal ultrasound, which contributes to difficulties in obtaining good image quality. When 3D-EAUS is performed to mirror screening settings, it adds no convincing diagnostic power to clinical examination in the diagnosis of OASI.

Diagnostic capabilities of transperineal ultrasound (TPUS) to evaluate anal sphincter defect post obstetric anal sphincter injury (OASIS)? A systematic review

INTRODUCTION

Endoanal ultrasound (3D-EAUS) is the gold standard imaging investigation for evaluating the anal sphincter; unfortunately, it is not universally available in most obstetric units. This study aims to appraise the ability of transperineal ultrasound (TPUS) compared with 3D-EAUS as the gold standard to identify anal sphincter defects after primary repair of OASIS.

METHODS

A systematic search of major databases to identify diagnostic accuracy of 3D-TPUS in evaluating anal sphincter defects. Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines were designed for this systematic review. The risk of bias and applicability concerns were assessed using the QUADAS-2 tool. Our eligibility criteria are patients with a history of primary repair of anal sphincter injuries (OASIS). They were followed up after the primary repair to detect the anal sphincter defect using 3D-TPUS vs. 3D-EAUS as a gold standard.

RESULTS

Two eligible observational studies were included and assessed for risk of bias using the QUADAS-2 tool and showed a low risk of bias and a low risk of concerns. 3D-TPUS had various sensitivity to detect external anal sphincter defects in two studies; meanwhile, the specificity was around 67-70%. For detecting the internal anal sphincter defects, 3D-TPUS had low sensitivity but high specificity (93-94%).

CONCLUSION

3D-TPUS had various sensitivity to detect external anal sphincter defects and low sensitivity to detect internal anal sphincter defects. On the other hand, 3D-TPUS had low specificity for detecting external anal sphincter defects and high specificity for detecting internal anal sphincter defects.

Immediate postpartum assessment of the anal sphincter by endovaginal ultrasound: An experimental study

INTRODUCTION AND HYPOTHESIS

Obstetric anal sphincter injuries are frequently missed and carry a significant risk for the development of anal incontinence. Immediate postpartum endoanal ultrasound increases identification of these injuries but is rarely employed. We hypothesize that endovaginal ultrasound could be a feasible and easily available alternative sonographic tool to improve early diagnosis of anal sphincter tears.

METHODS

We conducted a prospective experimental study including 160 primiparous women. Shortly after vaginal delivery, patients underwent clinical and sonographic perineal examinations. We analyzed the feasibility of anal sphincter assessment by endovaginal ultrasound and its potential contribution in the early diagnosis of anal sphincter injuries.

RESULTS

Sonographic assessment of the anal sphincter was analyzable for 136 patients (85.0%). Causes of non-analyzability included air artifacts (6.9%), lack of distinction between the external anal sphincter and surrounding tissues (9.4%) and distortion artifacts (9.4%). Patients in the non-analyzable ultrasound subgroup were less likely to have delivered in a dorsal lithotomy position (62.5% vs. 85.3 %) and more likely to have had an episiotomy (33.3% vs. 14.0%), and their risk of sphincter injury was more frequently classified as "improbable" on clinical examination (91.7% vs. 61.0%). Ultrasounds were analyzable for 96.4% of patients clinically reported as having "possible" or "certain" sphincter injuries. The incidence of anal sphincter injury was 16.9% for clinical observation and 20.0% with associated sonographic examination.

CONCLUSIONS

Endovaginal ultrasound could be used as a complementary tool in assessment of the anal sphincter in high-risk patients. Its feasibility and easy availability make this technique a promising tool for improving the management of anal sphincter tears.

Immediate postpartum assessment of the anal sphincter by endovaginal ultrasound: a new technical approach

INTRODUCTION AND HYPOTHESIS

In this study we described a new technical approach to adapt endovaginal ultrasound scanning of the anal sphincter complex to the immediate postpartum period.

METHODS

We analyzed the clinical and ultrasonographic examinations of 18 primiparous women presenting deep perineal tears with potential or clearly identified lesions of the anal sphincter. Potential anal sphincter lesion was defined as a second degree perineal tear extending close to the anal sphincter with exposition of its capsule or muscular fibers. We reported interesting ultrasonographic images explaining our technique in a video.

RESULTS

We reported clinical and ultrasonographic features in nine cases of grade 2, four cases of grade 3a, four cases of grade 3b and one case of grade 3c perineal tears. The ultrasonographic examination confirmed the intact state of the anal sphincter complex in all patients with clinical grade 2 tears except one in which a grade 3b lesion was detected. We were not able to identify external anal sphincter lesions on ultrasound in any of the patients with clinical grade 3a tears. In patients with clinical grade 3b tears, the ultrasound confirmed the external anal sphincter lesion in all cases, but revealed additional involvement of the internal anal sphincter in 1 case (grade 3c).

CONCLUSION

Immediate postpartum endovaginal ultrasound could be a promising technique to improve the management of perineal traumas after vaginal delivery.

Postpartum ultrasound for the diagnosis of obstetrical anal sphincter injury

This review presents the available data on the diagnosis of obstetrical anal sphincter injury by postnatal ultrasound imaging. There is increasing evidence that anal sphincter tears are often missed after childbirth and, even when diagnosed, often suboptimally repaired, with a high rate of residual defects after reconstruction. Even after postpartum diagnosis and primary repair, 25% to 50% of patients will have persistent anal incontinence. As clinical diagnosis may fail in the detection and classification of obstetrical anal sphincter injury, the use of imaging has been proposed to improve the detection and treatment of these lacerations. Notably, 3-dimensional endoanal ultrasound is considered the gold standard in the detection of obstetrical anal sphincter injury, and recently, 4-dimensional transperineal ultrasound, commonly available in obstetrical and gynecologic settings, has proven to be effective as well. Avoidance of forceps delivery when possible, performance of a rectal examination after vaginal delivery and before repair of any severe perineal tear, and offering sonographic follow-up at 10 to 12 weeks after vaginal delivery in high-risk women (maternal age of ≥35 years, vaginal birth after cesarean delivery, forceps, prolonged second stage of labor, overt obstetrical anal sphincter injury, shoulder dystocia, and macrosomia) may help reduce morbidity arising from anal sphincter tears.

Establishing a peripartum perineal trauma clinic: a narrative review

INTRODUCTION AND HYPOTHESIS

Obstetric anal sphincter injury (OASI) is not rare, and its consequences are multiple and potentially severe, especially for young women. Some dedicated perineal clinics have been established to improve the management of OASI. Despite their obvious importance, these specific clinics are underrepresented and underdeveloped. The objectives of this review are to explore various options for developing a peripartum perineal clinic and to compare the different practices regarding the mode of delivery for subsequent pregnancies after an OASI.

METHODS

This narrative review covers information from patients' questionnaires specific to anal incontinence, anal physiology assessment, pelvic floor and anal sphincter imaging, and the arguments for choosing the mode of delivery after an OASI.

RESULTS

This review highlights the extensive range of practices regarding the delivery mode after an OASI throughout national professional organizations and experienced perineal clinics.

CONCLUSION

This review summarizes the different choices in developing a perineal clinic to facilitate their development in promoting health care and education specific for peripartum women concerning the perineal consequences of delivery for obstetrician-gynaecologists, family doctors, and residents.

Transperineal anal sphincter complex evaluation after obstetric anal sphincter injuries: With or without tomographic ultrasound imaging technique?

OBJECTIVES

"Significant" obstetric anal sphincter injuries (OASIS) have been defined as visible defects of at least 30° in at least 4/6 slices using tomographic ultrasound imaging (TUI) with transperineal ultrasound (TPUS). The objective of this study was to assess if TUI is mandatory for the evaluation of OASIS.

METHODS

Patients with a history of OASIS were evaluated by performing 3D-endoanal ultrasound (EAUS) and 3D-TPUS with and without TUI. Any damage to the internal (IAS) or external (EAS) anal sphincters was recorded and scored using the Starck's and the Norderval's systems. Intraobserver and inter-techniques correlations were calculated.

RESULTS

From September 2012 to May 2015, 63 women, mean age 32.5 ± 4.6 years, with OASIS (3a: 26 pts., 41.3 %; 3b: 26 pts., 41.3 %; 3c: 6 pts., 9.5 %, 4: 4 pts., 6.3 %, "button hole" tear: 1 pt., 1.6 %). Inter-technique and intraobserver correlations were excellent (TUI: k = 0.9; sweeping technique: k = 0.85; EAUS: k = 0.9) in determining OASIS. Using the Starck's Score, excellent correlation was found for both TPUS modalities (TUI: k = 0.86; sweeping technique: k = 0.89). However, for the different individual parameters, the correlation was moderate for EAS depth (TUI: k = 0.44; sweeping technique: k = 0.5) and good for IAS depth (TUI: k = 0.7; sweeping technique: k = 0.78). Similar results were found using the Norderval's classification.

CONCLUSIONS

OASIS can be assessed by TPUS without TUI technique, dragging the rendered box and following the anal canal from the anal verge to the anorectal junction in the longitudinal plane and describing findings.

Obstetric anal sphincter injuries: strategies for prevention, diagnosis, and management

Obstetric anal sphincter injuries (OASIS) are one of the most common causes of anal incontinence (AI) in women of reproductive age and can have a significant impact on quality of life. However, many women do not report symptoms to their physicians because of embarrassment and shame. Therefore, prevention and diagnosis of the tear is essential. Diagnostic strategies have evolved considerably in recent years, with an increase in prevalence of OASIS as a consequence. The use of 3D endoanal (3D-EAUS) and 4D transperineal ultrasound (4D-TPUS), in addition to standard clinical examination have enhanced the detection of OASIS. Once identified, adequate repair by a skilled practitioner and optimal postpartum management should be ensured in order to reduce the risk of anal incontinence. This review presents the available evidence on strategies for prevention, diagnosis, and management of OASIS.

Tools for fecal incontinence assessment: lessons for inflammatory bowel disease trials based on a systematic review

BACKGROUND

Fecal incontinence is a disabling condition affecting up to 20% of women.

OBJECTIVE

We investigated fecal incontinence assessment in both inflammatory bowel disease and non-inflammatory bowel disease patients to propose a diagnostic approach for inflammatory bowel disease trials.

METHODS

We searched on Pubmed, Embase and Cochrane Library for all studies on adult inflammatory bowel disease and non-inflammatory bowel disease patients reporting data on fecal incontinence assessment from January 2009 to December 2019.

RESULTS

In total, 328 studies were included; 306 studies enrolled non-inflammatory bowel disease patients and 22 studies enrolled inflammatory bowel disease patients. In non-inflammatory bowel disease trials the most used tools were the Wexner score, fecal incontinence quality of life questionnaire, Vaizey score and fecal incontinence severity index (in 187, 91, 62 and 33 studies). Anal manometry was adopted in 41.2% and endoanal ultrasonography in 34.0% of the studies. In 142 studies (46.4%) fecal incontinence evaluation was performed with a single instrument, while in 64 (20.9%) and 100 (32.7%) studies two or more instruments were used. In inflammatory bowel disease studies the Wexner score, Vaizey score and inflammatory bowel disease quality of life questionnaire were the most commonly adopted tools (in five (22.7%), five (22.7%) and four (18.2%) studies). Anal manometry and endoanal ultrasonography were performed in 45.4% and 18.2% of the studies.

CONCLUSION

Based on prior validation and experience, we propose to use the Wexner score as the first step for fecal incontinence assessment in inflammatory bowel disease trials. Anal manometry and/or endoanal ultrasonography should be taken into account in the case of positive questionnaires.

Risk of obstetric anal sphincter injuries (OASIS) and anal incontinence: A meta-analysis

BACKGROUND

Obstetric anal sphincter injuries (OASIS) are the commonest cause of anal incontinence in women of reproductive age. We determined the risk of anal sphincter defects diagnosed by ultrasound, and the risk of anal incontinence in (i) all women who deliver vaginally, (ii) in women without clinical suspicion of OASIS, and (iii) after primary repair of sphincter injury, by systematic review.

METHODS

We searched major databases until June 2018, without language restrictions. Random effects meta-analysis was used to obtain pooled estimates of ultrasound diagnosed OASIS and risk of anal incontinence symptoms at various time points after delivery, and of persistent sphincter defects after primary repair. We reported the association between ultrasound diagnosed OASIS and anal incontinence symptoms using relative risk (RR) with 95 % CI.

RESULTS

We included 103 studies involving 16,110 women. Of all women who delivered vaginally, OASIS were diagnosed on ultrasound in 26 % (95 %CI, 21-30, I² = 91 %), and 19 % experienced anal incontinence (95 %CI, 14-25, I² = 92 %). In women without clinical suspicion of OASIS (n = 3688), sphincter defects were observed in 13 % (10-17, I² = 89 %) and anal incontinence experienced by 14 % (95 % CI: 6-24, I² = 95 %). Following primary repair of OASIS, 55 % (46-63, I² = 98 %) of 7549 women had persistent sphincter defect with 38 % experiencing anal incontinence (33-43, I² = 92 %). There was a significant association between ultrasound diagnosed OASIS and anal incontinence (RR 3.74, 2.17-6.45, I² = 98 %).

INTERPRETATION

Women and clinicians should be aware of the high risk for sphincter defects following vaginal delivery even when clinically unsuspected. This underlines the need of careful and systematic perineal assessment after birth to mitigate the risk of missing OASIS. We also noted a high rate of persistent defects and symptoms following primary repair of OASIS. This dictates the need for provision of robust training for clinicians to achieve proficiency and sustain competency in repairing OASIS.

Does exclusion of subcutaneous external anal sphincter on exoanal imaging matter?

OBJECTIVE

There is some speculation that an intact distal anal sphincter complex is of decisive importance for continence, although the external anal sphincter (EAS) is considered to be a single functional and anatomical entity. On tomographic translabial ultrasound (TLUS), the caudal slice at the level of the subcutaneous EAS is currently omitted from the diagnostic algorithm due to the prevalence of artifact at that level. The aim of this study was to determine the predictive value of assessment of the subcutaneous EAS on tomographic TLUS for anal incontinence (AI).

METHODS

This was a retrospective study of 463 women seen at our urogynecological service in 2015. All underwent a standardized questionnaire, including determination of St Mark's incontinence score (SMIS), clinical examination and three-/four-dimensional TLUS. On tomographic TLUS, EAS defect angles in slices one to seven were measured on maximum pelvic floor muscle contraction. A slice was defined as positive for a defect if the defect angle was ≥ 30°. The association between significant subcutaneous EAS trauma (i.e. defect angle of ≥ 30° in slice seven) and symptoms of AI, symptom bother score and SMIS was assessed. The performances of the standard six-slice model and the seven-slice model, including the subcutaneous EAS, in the prediction of AI were compared.

RESULTS

While there was a highly significant association between all measures of AI and significant EAS trauma in slice seven, addition of the seventh slice to the existing six-slice model did not improve the predictive value for AI.

CONCLUSION

As inclusion of the subcutaneous slice of the EAS on tomographic TLUS does not seem to improve the predictive value for AI, the current methodology for assessment of EAS trauma on tomographic TLUS can remain unchanged. Copyright © 2019 ISUOG. Published by John Wiley & Sons Ltd.

Is endoanal, introital or transperineal ultrasound diagnosis of sphincter defects more strongly associated with anal incontinence?

INTRODUCTION AND HYPOTHESIS

Our aim was to explore the association between anal incontinence (AI) and persistent anal sphincter defects diagnosed with 3D endoanal (EAUS), introital (IUS) and transperineal ultrasound (TPUS) in women after obstetric anal sphincter injury (OASI) and study the association between sphincter defects and anal pressure.

METHODS

We carried out a cross-sectional study of 250 women with OASI recruited during the period 2013-2015. They were examined 6-12 weeks postpartum or in a subsequent pregnancy with 3D EAUS, IUS and TPUS and measurement of anal pressure. Prevalence of urgency/solid/liquid AI or flatal AI and anal pressure were compared in women with a defect and those with an intact sphincter (diagnosed off-line) using Chi-squared and Mann-Whitney U test.

RESULTS

At a mean of 23.6 (SD 30.1) months after OASI, more women with defect than those with intact sphincters on EAUS had AI; urgency/solid/liquid AI vs external defect: 36% vs 13% and flatal AI vs internal defect: 27% vs 13%, p < 0.05. On TPUS, more women with defect sphincters had flatal AI: 32% vs 13%, p = 0.03. No difference was found on IUS. Difference between defect and intact sphincters on EAUS, IUS and TPUS respectively was found for mean [SD] maximum anal resting pressure (48 [13] vs 55 [14] mmHg; 48 [12] vs 56 [13] mmHg; 50 [13] vs 54 [14] mmHg) and squeeze incremental pressure (33 [17] vs 49 [28] mmHg; 37 [23] vs 50 [28] mmHg; 36 [18] vs 50 [30] mmHg; p < 0.01).

CONCLUSIONS

Endoanal ultrasound had the strongest association with AI symptoms 2 years after OASI. Sphincter defects detected using all ultrasound methods were associated with lower anal pressure.

Parturition mode recommendation and symptoms of pelvic floor disorders after obstetric anal sphincter injuries

INTRODUCTION AND HYPOTHESIS

Our primary objective was to evaluate parturition mode (PM) recommendations following obstetric anal sphincter injuries (OASIs) and adherence to these recommendations and to evaluate recurrence of OASIs in women who had a subsequent vaginal delivery (VD). The hypothesis was that adherence to the PM recommendations leads to a reasonable OASI recurrence rate.

METHODS

This was a retrospective observational cohort study of patients with previous OASIs between 2010 and 2016. After an outpatient visit including 3D transperineal ultrasound to screen for pelvic floor and anal sphincter injuries, all patients received recommendations for a subsequent PM. Patients were invited to complete validated questionnaires 2 to 5 years post-OASIs.

RESULTS

The majority of invited patients (265/320) attended follow-up, with 264 receiving a recommendation for PM. Only 5.6% did not adhere to the received recommendation. One hundred sixty-one patients delivered again, 58% had a VD, and 42% had a cesarean section (CS). Recurrence of OASIs was observed in 4.3% of the patients that had a VD. Fecal incontinence occurred in 4.9%, however any form of anal incontinence in 48% of patients. While dyspareunia was common in patients with residual external anal sphincter (EAS) injuries and levator ani muscle (LAM) avulsions, anal pain occurred more frequently in EAS injuries and fecal incontinence in LAM avulsions.

CONCLUSIONS

This study showed that the vast majority of patients followed PM recommendations, and this resulted in a low recurrence of OASIs with a high CS rate. Fecal incontinence after OASIs was correlated with the degree of OASIs.

Exo-anal imaging of the anal sphincter: a comparison between introital and transperineal image acquisition

INTRODUCTION AND HYPOTHESIS

Three-dimensional exoanal ultrasound imaging of the anal sphincter may be obtained transperineally with a convex probe, or at the introitus with a transvaginal probe. We hypothesised that introital acquisition would yield better quality and more reproducible evaluation.

METHODS

We acquired three 3D volumes of the anal sphincter (one transperineal transverse with a 4- to 8-MHz convex probe and two introital with a 5- to 9-MHz probe in transverse and mid-sagittal view) in 20 representative women attending the gynaecology clinic. Each 3D dataset was anonymised and hence blinded for clinical data and for acquisition method. Images were analysed off-line by two expert specifically trained ultrasonographers in a random order to assess image quality, sphincter integrity and sphincteric measurements. We assessed the intra- and interrater agreement by the Cohen's kappa (κ) and by the intraclass correlation coefficient for categorical and continuous variables respectively.

RESULTS

The mid-sagittal introital acquisition had most inconclusive images owing to unsatisfactory quality, on which raters agreed (К = 0.80). Subsequently, agreement in the anal sphincter evaluation between transverse introital and transperineal acquisitions was compared. Agreement on internal anal sphincter gap was excellent for both transverse introital (К = 0.87) and transperineal acquisition (К = 0.93). Agreement on external anal sphincter discontinuity was excellent for the transperineal acquisition (К = 0.87) and good for the transverse introital acquisition (К = 0.73). Intra- and interrater agreement of external and internal anal sphincteric measurements were best for transperineal acquisitions.

CONCLUSIONS

In our hands, transperineal acquisition with a 4- to 8-MHz probe performed better than introital acquisition with a 5- to 9-MHz probe in the assessment of the anal sphincter complex.

Comparison of transperineal and endoanal ultrasound in detecting residual obstetric anal sphincter injury

INTRODUCTION

Endoanal ultrasound is considered the gold standard when assessing the obstetric anal sphincter complex. Due to its relative intrusiveness and economic cost, other ultrasound modalities are on the rise, such as transperineal ultrasound with a convex probe. The aim of our study was to evaluate the agreement between endoanal ultrasound scores (EAUS score) and transperineal ultrasound scores (TPUS score) in assessing residual obstetric anal sphincter defects.

MATERIAL AND METHODS

Fifty-nine women were examined 6 months after primary suturing of obstetric anal sphincter injury with two ultrasound modalities. A standardized scoring system analyzing the length, depth and radial extent of both the external (EAS) and internal (IAS) sphincter was used. Wexner fecal incontinence score was used to assess the patients' symptoms.

RESULTS

Transperineal ultrasound scores score showed a strong significant correlation with EAUS score during both pelvic floor relaxation and contraction: Spearman's rho [r_s ] = 0.74, P < 0.001, and r_s  = 0.77, P < 0.001, respectively. For both EAS and IAS, significant correlations were found for all parameters, that is, length, depth and angle between both EAUS and TPUS. A statistically significant correlation was found between EAUS score and Wexner score (r_s  = 0.36, P = 0.005). A significant correlation between the EAS-EAUS score (r_s  = 0.36, P = 0.005) and Wexner score was found, but no significance was found between IAS-EAUS score and Wexner score (r_s  = 0.22, P = 0.097). Significant correlations were found for Wexner score and TPUS score in resting state (r_s  = 0.36, P = 0.01) and contracting state (r_s  = 0.28, P < 0.05), and between Wexner score and EAS-TPUS score in resting state (r_s  = 0.32, P = 0.02).

CONCLUSIONS

The results indicated a strong agreement between endoanal and transperineal ultrasound in assessing residual obstetric anal sphincter defects 6 months after primary suturing. Furthermore, a weak significant correlation was found between the ultrasound scores and the patients' Wexner fecal incontinence score.

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

BACKGROUND

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.

OBJECTIVE

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.

STUDY DESIGN

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.

RESULTS

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.

CONCLUSION

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.

The Role of Three-Dimensional Endoanal Ultrasound on Diagnosis and Classification of Sphincter Defects After Childbirth

BACKGROUND

Diagnostic tests for fecal incontinence have been improved over time. This study aims to evaluate the role of Three-dimensional endoanal ultrasound (3D-EUS) and the Starck's score in the assessment and treatment of obstetric sphincter injuries.

METHODS

A prospective observational study was performed including primiparous women who were evaluated at 20 wk of pregnancy and 3 mo after childbirth. Sphincter defects were classified according to the Starck's and Obstetrical Anal Sphincter Injuries classifications. Patients also completed the Fecal Incontinence Quality of Life and the Wexner questionnaires before and after childbirth.

RESULTS

Sphincter defects were detected in 45% of the 56 women included, although 85% had an uneventful delivery. Most defects were found isolated to the external anal sphincter except for two cases, classified by a Starck's score >8. Fecal Incontinence Quality of Life and Wexner questionnaires showed a rate of symptomatic patients of around 46%. We observed that 30% of patients with sphincter injuries remained asymptomatic.

CONCLUSIONS

The 3D-EUS is a useful test in assessing sphincter defects after childbirth. This method makes it possible to detect small sphincter defects that otherwise would have gone unnoticed, as 30% of patients with sphincter injuries were asymptomatic. In addition, both the 3D-EUS and the Starck's score were valuable in establishing an algorithm for the treatment of obstetric sphincter injuries.

Exoanal Imaging of the Anal Sphincters

Since its introduction in the early 1990s, endoanal sonography has become the mainstay of morphologic assessment of the anal canal and sphincter, especially for obstetric anal sphincter trauma. Lack of availability of suitable systems and the invasive nature of the method have limited uptake and clinical utility. More recently, exoanal or transperineal/translabial tomographic imaging has been developed as a noninvasive alternative. This pictorial overview aims to introduce the reader to this new diagnostic modality and to demonstrate common findings in asymptomatic and symptomatic women.

Interobserver agreement in perineal ultrasound measurement of the anovaginal distance: a methodological study

INTRODUCTION AND HYPOTHESIS

Objective outcome measures of the extent of laceration at delivery are needed. In this study we evaluated and describe here a method for learning perineal ultrasound measurement of the anovaginal distance (AVD). The learning period needed for examiners proficient in vaginal ultrasound examination and the interobserver agreement after reaching proficiency in AVD measurement were determined. The hypothesis was that the method is feasible to learn and reproducible for use in further research.

METHODS

The method was taught by an examiner experienced in perineal ultrasonography. The distance between the mucosal margin of the internal anal sphincter was measured with a vaginal probe. The studied examiners measured the AVD until similar results (±5 mm) were achieved. The AVD in 40 women was then measured and documented by two examiners who were blinded to each other's results. Interobserver agreement was calculated using the kappa score.

RESULTS

Examiners with previous experience in vaginal ultrasonography had learned the method after performing five sets of comeasurements. The AVD measurements after the learning period showed almost perfect agreement (κ = 0.87) between the examiners.

CONCLUSIONS

The method for perineal ultrasound measurement of AVD was learned quickly with high interobserver agreement. The method is feasible to learn and reproducible for use in further research.