Defects on endoanal ultrasound and anal incontinence after primary repair of fourth-degree anal sphincter rupture: a study of the anal sphincter complex and puborectal muscle

Follow up of women after obstetric anal sphincter injuries (OASI)-What is the role of anorectal testing?

AIMS

To evaluate the benefit of performing anorectal studies on all women following primary obstetric anal sphincter injury (OASI) repair over performing them on symptomatic women only.

METHODS

Women who attended perineal clinic between 2007 and 2020 underwent symptom assessment and anorectal studies at 6 weeks and 6 months postpartum. Anorectal studies including endo anal ultrasound (EAUS) and anal manometry (AM) were performed. The anorectal studies of symptomatic women who were the case group, were compared with asymptomatic women who were the control group.

RESULTS

A total of 1348 women were seen in the perineal clinic over 13 years. A total of 454 (33.7%) women were symptomatic. A total of 894 (66.3%) women were asymptomatic. A total of 313 (35%) asymptomatic women had two abnormal anorectal studies, 274 (31%) had abnormal AM alone, and 86 (9.6%) had abnormal EAUS alone. A total of 221 (24.7%) asymptomatic women had normal anorectal studies.

CONCLUSION

Almost 70% of women were asymptomatic 6 months following primary OASI repair. Most had at least one abnormal anorectal study result. Selectively performing anorectal tests on symptomatic women would not identify asymptomatic women at risk of future faecal incontinence following further vaginal birth. Without anorectal study results, women would not receive accurate counseling about the risks of vaginal birth. Anorectal studies should be offered to all women following OASI where resources allow.

Can ultrasound 10 days after obstetric anal sphincter injury predict anal incontinence at long-term follow-up?

INTRODUCTION AND HYPOTHESIS

The objective was to investigate whether endoanal ultrasound (EAUS) performed 10 days after a primary repaired obstetric anal sphincter injury (OASIS) can predict the severity of anal incontinence (AI) in the long term.

METHODS

This prospective cohort study included women with a primary repaired 3b-degree tear, 3c-degree tear or fourth-degree tear at Aarhus University Hospital, Denmark, from 1 September 2010 to 31 May 2011. Clinical assessment and EAUS were performed on day 2, day 10, and day 20 after delivery. Functional outcomes were assessed using a questionnaire at the time of all clinical visits and at the long-term follow-up, 7 years after delivery. AI was graded according to the Wexner score and EAUS defects were graded according to the Starck score.

RESULTS

Ninety-six out of 99 women consented to participate. Five women had a secondary sphincter repair and were subsequently excluded from follow-up. Fifty-seven women underwent both EAUS 10 days after delivery and answered the long-term follow-up questionnaire. Median follow-up time was 7.7 years (IQR 7.4-7.8). Mean Wexner score was 4.4 ± 4.8 10 days after delivery and 2.5 ± 2.8 at follow-up; thus, the Wexner score improved over time (p = 0.01). Ultrasound sphincter defects were found in 82.6% of the women. Mean Starck score was 3.0 ± 1.8. The risk of AI was 0% (95% CI 0.0-30.8) if the Starck score was 0. No correlation was found between the Starck score and the Wexner score at follow-up.

CONCLUSIONS

We found that performing EAUS in the puerperium following OASIS has limited value in predicting long-term AI.

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.

Management of subsequent pregnancies following fourth-degree obstetric anal sphincter injuries (OASIS)

OBJECTIVES

The management of subsequent pregnancy in women who sustained OASIS remains an enigma. Nearly all studies include all grades of OASIS including fourth-degree tears. In addition, most protocols require endoanal ultrasound and anal manometric assessment to provide advice regarding mode of delivery. In reality, most women who sustain an OASI do not undergo these investigations. The aims of our study were firstly to evaluate outcomes of fourth-degree OASIS in terms of sphincter defects, anal manometry and anal incontinence symptoms. Secondly, we wished to review recommendations made regarding subsequent mode of delivery after fourth-degree OASIS according to different published protocols.

STUDY DESIGN

An observational study of all women who had undergone a primary repair of a fourth-degree tear and seen in the perineal clinic of a tertiary urogynaecology unit between January 2006 and December 2017. Three-dimensional endoanal ultrasound and anal manometry were performed on all women, and symptoms assessed using the validated modified St Mark's Score for anal incontinence. Diagnostic test accuracy analysis was performed for use of symptoms in predicting abnormal investigations.

RESULTS

74 fourth-degree tears were identified (mean follow-up 5.9 months; SD 11.5). Endoanal scan showed an internal anal sphincter defect in 77 % and an external anal sphincter defect in 49 %. Only 18 % had no defect. The mean incremental pressure rise was 12.6 mmHg (SD 15.5). 61 % were asymptomatic with a mean St Mark's Score of 3.8 (SD 5.4). The presence of symptoms alone had poor accuracy in predicting abnormal investigations. Based on Royal College of Obstetricians and Gynaecologists guidance, only 7% would not be offered a caesarean section as they are asymptomatic women with normal scan and manometry findings and would be counselled for a vaginal delivery.

CONCLUSIONS

Given that only a few units offer these specialist investigations to their OASI population, it would be reasonable to offer caesarean section to all women who have sustained a fourth-degree tear. However, in centres where endoanal ultrasound and anal manometry are available, individualised counselling can be offered.

Predictors of patient preference for mode of delivery following an obstetric anal sphincter injury

OBJECTIVES

Patients who sustain an Obstetric Anal Sphincter Injury (OASI) have the opportunity to select an elective caesarean section over a vaginal delivery in subsequent pregnancies. It remains unclear whether there are identifiable factors which predict expectant mothers' choices. The primary aim of our study was to explore this issue further in a consecutive group of patients who had suffered OASI.

STUDY DESIGN

Data were retrospectively collected for patients attending a specialist OASIS clinic between July 2016 and February 2018. Information routinely collected in clinical practice was considered including mode of previous delivery, severity of OASI, combined with anal incontinence symptoms and endoanal ultrasound results. Logistic regression analysis was used to explore the relationship between these variables and the preferred mode of delivery.

RESULTS

A total of 188 patients were identified of whom 153 had complete data for analysis. Approximately 30% (n = 45) of patients preferred to have a caesarean section in their subsequent pregnancy. Bivariate analysis revealed significant associations between choosing a caesarean section in subsequent pregnancy and individuals with major tears (p = 0.001), high anal incontinence scores (p = 0.001) and defects on endoanal ultrasound (p < 0.001). Logistic regression analysis showed statistically significant associations between Caucasian ethnicity (Odds ratio (OR) 12.6, 95% CI 2.4-69.9) and endoanal ultrasound results (OR 2.3, 95% CI 1.7-3.2) with preference for caesarean section.

CONCLUSION

Our data suggests that emphasis is placed by patients on endoanal ultrasound results when making their decision about mode of delivery in a subsequent pregnancy, suggesting a useful application of this tool. Ethnicity is a strong predictor of choice of delivery after OASI and may be potentially useful in forecasting maternity unit services.

Anatomic and functional evaluation of the levator ani muscle after an obstetric anal sphincter injury

PURPOSE

To study the relationship between symptoms of anal incontinence (AI) and the anatomy and functionality of the levator ani muscle in women with a history of obstetric anal sphincter injury (OASI).

METHODS

This is a cohort study including patients with OASI from 2013 to 2016. Patients were assessed by a physical examination, endoanal ultrasound using Starck Scale, perineometry and 4D transperineal ultrasound. AI in all patients was measured with the Wexner scale. Correlation between variables has been analyzed in these patients.

RESULTS

72 patients were analyzed: 28 with a IIIA degree tear, 26 with a IIIB, 13 with a IIIC and 5 with a IV. 38 patients showed a residual anal sphincter (AS) defect on endoanal ultrasound with an average Starck score of 6.5 ± 3.7. 21 patients expressed AI, with an average Wexner score of 4.1 ± 2.4. In 27 (37.5%) patients, a levator ani avulsion was observed: 17 unilateral and 10 bilateral. Patients with a levator ani defect had weaker pelvic floor muscle (PFM) function. These differences were statistically significant with perineometry (p = 0.01 and p = 0.03) but not for the Oxford test (p = 0.08). Patients with a residual AS defect as well as an injury to the levator ani muscle expressed greater AI symptomatology than patients with residual sphincter injury who maintain the integrity of the levator ani: Wexner 4.9 0.9 vs 3.3 1 (p = 0.02).

CONCLUSIONS

The PFM has correlation with AI symptom development in patients with a history of OASI. Therefore, we suggest a key role of anatomical and functional assessments of the levator ani muscle in these patients.

Efficacy of Percutaneous Posterior Tibial Nerve Stimulation for the Management of Fecal Incontinence in Multiple Sclerosis: A Pilot Study

BACKGROUND

Fecal incontinence is a debilitating and highly prevalent problem among multiple sclerosis patients. Conservative therapies often fail to provide benefit. Posterior tibial nerve stimulation is a minimally invasive neuromodulatory therapy with proven efficacy for fecal incontinence in non-neurological settings.

OBJECTIVE

To evaluate the efficacy of posterior tibial nerve stimulation in treating multiple sclerosis-related fecal incontinence.

METHODS

Consecutive multiple sclerosis patients with fecal incontinence that had failed conservative therapy received posterior tibial nerve stimulation between 2012 and 2015. All patients had previously undergone anorectal physiology tests and endoanal ultrasound. Patients whose Wexner incontinence score reduced below 10 post-therapy or halved from baseline were deemed responders.

RESULTS

Thirty-three patients (25 female, median age 43 years) were included. Twenty-three (70%) had urge, 4 (12%) passive, and 9 (27%) mixed fecal incontinence. Twenty-six (79%) were classified as responders. The majority of subjects had relapsing-remitting multiple sclerosis (67%); those had a significantly higher response rate (95% vs. 67% and 50% in primary and secondary progressive respectively, P < 0.05). Responders tended to be more symptomatic at baseline and had greater improvements in bowel symptom scores and quality of life scores with therapy.

CONCLUSION

Posterior tibial nerve stimulation demonstrates potential as an effective therapy for fecal incontinence in multiple sclerosis. These findings provide the basis for future more definitive controlled studies.

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

OBJECTIVE

To compare the sensitivity and specificity of two- (2D) and three- (3D) dimensional transperineal ultrasound (TPUS) and 3D endovaginal ultrasound (EVUS) with the gold standard 3D endoanal ultrasound (EAUS) in detecting residual defects after primary repair of obstetric anal sphincter injuries (OASIS).

METHODS

External (EAS) and internal (IAS) anal sphincters were evaluated by the four ultrasound modalities in women with repaired OASIS. 2D-TPUS was evaluated in real-time, whereas 3D-TPUS, 3D-EVUS and 3D-EAUS volumes were evaluated offline by six blinded readers. The presence/absence of any tear in EAS or IAS was recorded and defects were scored according to the Starck system. Sensitivity, specificity and predictive values were calculated, using 3D-EAUS as reference standard. Inter- and intraobserver analyses were performed for all 3D imaging modalities. Association between patients' symptoms (Wexner score) and ultrasound findings (Starck score) was calculated.

RESULTS

Images from 55 patients were analyzed. Compared with findings on 3D-EAUS, the agreement for EAS evaluation was poor for 3D-EVUS (κ = 0.01), fair for 2D-TPUS (κ = 0.30) and good for 3D-TPUS (κ = 0.73). The agreement for IAS evaluation was moderate for both 3D-EVUS (κ = 0.41) and 2D-TPUS (κ = 0.52) and good for 3D-TPUS (κ = 0.66). Good intraobserver (3D-EAUS, κ = 0.73; 3D-TPUS, κ = 0.78) and interobserver (3D-EAUS, κ = 0.68; 3D-TPUS, κ = 0.60) agreement was reported. Significant association between Starck and Wexner scores was found only for 3D-EAUS (Spearman's rho = 0.277, P = 0.04).

CONCLUSIONS

2D-TPUS and 3D-EVUS are not accurate modalities for the assessment of anal sphincters after repair of OASIS. 3D-TPUS shows good agreement with the gold standard 3D-EAUS and a high sensitivity in detecting residual defects. It, thus, has potential as a screening tool after primary repair of OASIS. Copyright © 2016 ISUOG. Published by John Wiley & Sons Ltd.

Residual defects after repair of obstetric anal sphincter injuries and pelvic floor muscle strength are related to anal incontinence symptoms

INTRODUCTION AND HYPOTHESIS

The aim was to analyze the correlation between residual anal sphincter (AS) defects and pelvic floor muscle (PFM) strength on anal incontinence (AI) in patients with a history of obstetric AS injuries (OASIS).

METHODS

From September 2012 to February 2015, an observational study was conducted on a cohort of females who underwent repair of OASIS intrapartum. The degree of OASIS was scored intrapartum according to Sultan's classification. Participants were assessed at 6 months postpartum. Incontinence symptoms were evaluated using Wexner's score and PFM strength using the Modified Oxford Scale (MOS). 3D-endoanal ultrasound was performed to classify AS defects according to Starck's system. Correlation between Sultan's and Starck's classifications was calculated using Cohen's kappa and Spearman's rho (R_s) test. The impact of residual AS defects and PFM strength on AI was analyzed using a multiple regression model.

RESULTS

A total of 95 women were included in the study. Good correlation (κ= 0.72) was found between Sultan's and Starck's classifications. Significant positive correlation was observed between Wexner's score and both Sultan's (p = 0.023, R_s =0.212) and Starck's (p < 0.001, R_s =0.777) scores. The extent of the residual AS defect was the most relevant factor correlating with AI symptoms. In patients with severe AS injuries, higher MOS values were associated with lower Wexner's score.

CONCLUSIONS

The degree of AS tear measured intrapartum was the most important factor related to AI after primary repair of OASIS. PFM strength was associated with lower incontinence symptoms in the postpartum period.

Long-term function and morphology of the anal sphincters and the pelvic floor after primary repair of obstetric anal sphincter injury

AIM

More than 50% of women experience deteriorating continence over time following primary repair of obstetric anal sphincter injuries. The objectives of this study were to assess the function and morphology of the anal sphincters and pelvic floor in women with long-term faecal incontinence after sphincter repair (primary end-point) and to evaluate their correlation with severity of incontinence (secondary end-point).

METHOD

The participants in this prospective study were recruited from a cohort of all women who sustained third or fourth degree obstetric sphincter injury reconstruction (cases) from January 1976 to November 1991. The women who delivered immediately before and after each case, without sustaining obstetric damage, were included as controls. Cases and controls were stratified into three categories: (i) continent; (ii) minor incontinence; and (iii) severe incontinence. The function and morphology of the anal sphincters and pelvic floor were evaluated by MRI, three-dimensional endoanal ultrasonography and anorectal physiology tests.

RESULTS

Fifty-nine women (29 cases/30 controls; mean age 51/53 years; mean follow-up 23.7/24.1 years, respectively) were assessed. Morphologically, cases had a significantly shorter anterior external anal sphincter length compared with controls when evaluated by three-dimensional endoanal ultrasonography (8.6 vs 10.2 mm; P = 0.03). Functionally, cases with severe incontinence had a significantly shorter anterior sphincter length compared with cases with minor incontinence (7.7 vs 10.4 mm; P = 0.04). No correlation could be found between anal pressures and severity of incontinence in the case group.

CONCLUSIONS

Cases had a significantly shorter anterior external anal sphincter length. Functionally, anterior sphincter length correlated with increased severity of incontinence.