Endoanal sonography in assessment of fecal incontinence following obstetric trauma

Diagnosis and Treatment of Obstetric Anal Sphincter Injuries: New Evidence and Perspectives

Perineal injury during childbirth is a common event with important morbidity associated in particular with third-and-fourth degree perineal tears (also referred to as obstetric anal sphincter injuries-OASIS). Early diagnosis of these damages is mandatory to define a prompt therapeutic strategy and thus avoid the development of late-onset consequences, such as faecal incontinence. For this purpose, various diagnostic exams can be performed after a thorough clinical examination. The management of OASIS includes several measures and should be individualized according to the timing and features of the clinical presentation.

INCREASED OASIS INCIDENCE - INDICATOR OF THE QUALITY OF OBSTETRIC CARE?

In the era of new molecular, epigenetic and proteomic discoveries, birth canal injuries seem like outdated discussion. A vast increase in the incidence of obstetric anal sphincter injuries (OASIS) has been recorded in the last two decades despite advantages in modern medicine and new obstetric methods. This increase might be attributed to the new classification of perineal injury but also to the new imaging methods, including endoanal sonography, which earlier identifies injuries that previously were considered to be occult and actually underwent unrecognized, and which should have been recognized immediately postpartum. OASIS are third and fourth degree perineal injuries that occur during delivery. The reported incidence of OASIS varies from 0.1% to 10.9%. It is well known that third and fourth degree perineal injuries occur more often in primiparae, and in cases of macrosomic newborn, dorsoposterior position of fetal head and shoulder dystocia. The protective role of episiotomy is controversial. Birth canal injury during delivery can happen to any parturient woman. It is important for obstetricians to have this in mind at every delivery. Repercussions of OASIS are serious and can persist for life. They include emotional, psychological, social, physical and sexual disturbances. Therefore, it is very important to recognize the risk factors, diagnose the injury on time and treat it properly by a multidisciplinary team. Accordingly, it can be concluded that the increased incidence of OASIS is a result of better recognition of the risk factors, reduced rates of unrecognized sphincter injuries, adoption of the new classification and better postpartum imagining methods for detection of occult injuries.

Use of endoanal ultrasound for reducing the risk of complications related to anal sphincter injury after vaginal birth

BACKGROUND

During childbirth, many women sustain trauma to the perineum, which is the area between the vaginal opening and the anus. These tears can involve the perineal skin, the pelvic floor muscles, the external and internal anal sphincter muscles as well as the rectal mucosa (lining of the bowel). When these tears extend beyond the external anal sphincter they are called 'obstetric anal sphincter injuries' (OASIS). When women sustain an OASIS, they are at increased risk of developing anal incontinence either immediately following birth or later in life. Anal incontinence is associated with significant medical, hygiene and social problems. Endoanal ultrasound (EAUS) can be performed with a bedside scanner by inserting a small probe into the anus and the structures of the anal canal and perineum can be reviewed in real-time. We proposed that by examining the perineum with EAUS after the birth of the baby and before the tear has been repaired, there would be an increase in detection of OASIS. This increased detection could lead to improved primary repair of the external and internal anal sphincter resulting in reduced rates of anal incontinence and improved quality of life for women. EAUS may also have a role after perineal repair in the evaluation of residual injury and may help guide a woman's management in subsequent pregnancies and allow for early referral to specialised units, minimising long-term complications.

OBJECTIVES

To evaluate the effectiveness of EAUS in the detection of OASIS following vaginal birth and in reducing the risk of anal sphincter complications related to OASIS.

SEARCH METHODS

We searched the Cochrane Pregnancy and Childbirth Group's Trials Register (31 August 2015) and reference list of the one retrieved study.

SELECTION CRITERIA

Randomised control trials (RCTs) comparing EAUS versus no ultrasound in women prior to repair of perineal trauma and EAUS performed after perineal repair. RCTs published in abstract form only and trials using a cluster-randomised design were eligible for inclusion, but none were identified.Trials using a cross-over design and quasi-RCTs were not eligible for inclusion.

DATA COLLECTION AND ANALYSIS

The two review authors independently assessed the single trial for inclusion and assessed trial quality. Both review authors independently extracted data. Data were checked for accuracy.

MAIN RESULTS

We included one trial that randomised 752 primiparous women with clinically detectable second-degree perineal tears to either further assessment with EAUS prior to perineal repair or standard care. We assessed this trial as being at a low risk of bias. The trial reported women's anal incontinence at three and 12 months as well as their pain scores and quality of life assessment. The trial authors reported outcomes at three months for 719 women (364 in the experimental group, 355 in the control group, 4% loss to follow-up), and an outcome at 12 months for 684 women (342 in the experimental group, 342 in the control group, 9% loss to follow-up). Primary outcomeCompared with clinical examination (routine care), the use of EAUS prior to perineal repair was associated with a reduction in the rate of severe anal incontinence (defined as involuntary loss of faeces or flatus that constitutes social and/or hygiene problems, or as defined by authors), at greater than six months postpartum (risk ratio (RR) 0.48, 95% confidence interval (CI) 0.24 to 0.97, 684 women at the 12-month time point). Secondary outcomes Severe anal incontinence at less than six months was reduced with the use of EAUS prior to repair when compared with clinical examination (routine care) (RR 0.38, 95% CI 0.20 to 0.72, 719 women). However, increased perineal pain at three months was associated with the use of EAUS prior to perineal repair when compared with routine care (RR 5.86, 95% CI 1.74 to 19.72, 684 women). There was no clear difference in the number of women who reported any anal incontinence at either less than six months or equal to or greater than six months (outcomes not prespecified in our published protocol). Similarly, there was no clear difference between groups in terms of faecal incontinence, flatal incontinence, faecal urgency, or maternal quality of life. The study did not report any data on the need for secondary repair of external anal sphincter, dyspareunia, women's satisfaction with care or the planned or actual mode of birth in any subsequent pregnancy. We were unable to assess the detection rates of OASIS with EAUS from the included study because women with clinically-detected OASIS were excluded from randomisation.

AUTHORS' CONCLUSIONS

There is some evidence to suggest that EAUS prior to perineal repair is associated with reduced risk of severe anal incontinence but an increase in the incidence of perineal pain at three months postpartum. However, these results are based on one small study involving 752 women. The study took place in a large teaching hospital with an average to busy labour ward. The trial participants were similar to those found in most large obstetric units in developed countries, thus increasing applicability of the evidence, but were restricted to primiparous women.More research is needed to further evaluate the effectiveness of EAUS in the detection of OASIS following vaginal birth and in reducing the risk of anal sphincter complications related to OASIS. More high-quality RCTs are needed to fully evaluate the intervention before the routine use of EAUS on the labour ward could be supported. It would be particularly useful if future trials could assess detection rates of OASIS with EAUS versus clinical examination alone as this is the basis of the theory for improved outcomes with this intervention. Cost and the training required to implement EAUS should be considered, along with maternal quality of life and individual symptoms experienced by postnatal women . It would also be useful to follow up women after their subsequent vaginal births to determine if subsequent mode of delivery affects long-term outcomes. Future studies in multiparous women may also be useful.

Assessment of pubovisceral muscle defects and levator hiatal dimensions in women with faecal incontinence after vaginal delivery: is there a correlation with severity of symptoms?

AIM

We assessed pubovisceral muscle (PVM) defects, levator hiatal dimensions and anal sphincter defects using three-dimensional (3D) endovaginal and anorectal ultrasonography in women with previous vaginal delivery and faecal incontinence to determine the relationship between anatomic/functional findings and severity of faecal incontinence symptoms.

METHOD

This was a prospective, observational study including 52 women with faecal incontinence symptoms who had undergone vaginal delivery. Asymptomatic nulliparous women (n = 17) served as controls to provide reference values for pelvic floor measurements. All participants underwent 3D endovaginal and anorectal ultrasonography. We used an ultrasound score to identify and quantify the extent of PVM defects and sphincter damage and to measure levator hiatal dimensions. Incontinence was assessed using the Cleveland Clinic Florida Incontinence Scoring System.

RESULTS

Defects of the PVM were identified with 3D endovaginal ultrasonography in 27% of women with faecal incontinence who had undergone vaginal delivery. The incontinence score and the ultrasound score were significantly higher in women with a PVM defect. A significant, positive correlation was found between the incontinence score and the ultrasound score. The levator hiatal dimensions were significantly greater, and the positions of the anorectal junction and bladder neck were lower, in women who had undergone vaginal delivery than in nulliparous women.

CONCLUSION

As determined by the 3D ultrasound score, severity of incontinence is related to the extent of damage of the PVM, as well as of the anal sphincters. Additionally, vaginal delivery results in enlargement of the levator hiatus and a lower position of the anorectal junction and bladder neck compared with nulliparous women.

Endoanal ultrasound in benign anorectal disorders: clinical relevance and possibilities

Endoanal ultrasound is a well-established technique used to evaluate benign anorectal disorders. The technique is easy to perform, has a short learning curve and causes very little discomfort. Reconstruction of 3D images is possible. The clinical indications for endoanal ultrasound in benign anorectal diseases are fecal incontinence and peri-anal fistula. Sphincter defects can be depicted with precision and correlate perfectly with surgical findings. Furthermore, an impression of sphincter atrophy can be established. With perianal fistula the tracts can be visualized. Introducing hydrogen peroxide via the external fistula opening improves imaging. Endoanal ultrasound and MRI have comparable results in diagnosing anorectal disorders.

Diagnosis and management of obstetric anal sphincter injury

PURPOSE OF REVIEW

The purpose of this review is to outline optimum practice in diagnosis and management of obstetric anal sphincter injury. The review focuses briefly on prevention of the problem before outlining diagnosis of sphincter injury as well as immediate and long-term management of patients who have sustained such injuries.

RECENT FINDINGS

Increasing vigilance is vital in order that sphincter injury is not overlooked; immediate radiological assessment may play a role in diagnosis. Optimum anal sphincter repair should be followed by oral laxative administration to maintain sphincter integrity. Biofeedback physiotherapy and sacral nerve stimulation show great promise in treatment of persistent symptoms. Optimum mode of delivery in future pregnancies is not clearly defined, and decisions should be individualized.

SUMMARY

Because obstetric injury to the anal sphincter mechanism cannot always be prevented, efforts must focus on limiting its occurrence, documenting its severity and providing optimum therapy to women who have sustained it. Management includes routine postnatal review of at-risk women and antenatal assessment in future pregnancies to limit deterioration in continence after future deliveries.

Three-dimensional transperineal sonographic characteristics of the anal sphincter complex in nulliparous women

OBJECTIVE

To explore the morphological characteristics and normal biometry of the anal sphincter complex in nulliparous Chinese women using three-dimensional (3D) transperineal ultrasound.

METHODS

3D sonographic data from 55 nulliparous Chinese women (aged 19-38 years) who had no pelvic organ prolapse and no symptoms of pelvic floor dysfunction were retrieved from an image dataset and analyzed by offline post-processing. The morphological characteristics of the external and internal anal sphincters, puborectalis muscle and perineal body were assessed in the sagittal, coronal and axial views.

RESULTS

The external anal sphincter had three sonographic components: the circular main body, a subcutaneous part and an extension portion. It was significantly thinner at 12 o'clock than at the 3, 6 and 9 o'clock positions. The internal anal sphincter was seen as dark echolucent strips of equal thickness. In the mid-sagittal view, it started from the anal verge and ended at the anorectal junction. The perineal body was an ovoid structure covering the upper margin of the external sphincter, while the puborectalis muscle was banana-shaped in the sagittal view and was located behind the anorectal junction, extending downward along the inferior margin of the posterior external sphincter extension. Sonographic characteristics of the anal sphincter complex did not vary with age, weight, height or body mass index.

CONCLUSIONS

3D transperineal ultrasound clearly demonstrates the spatial relationships of each component of the anal sphincter complex. This should allow standardized measurement of the complex for investigations of its function.

Posterior pelvic floor disorders: a prospective comparison using introital ultrasound and colpocystodefecography

OBJECTIVE

To compare introital ultrasound with colpocystodefecography (CCD) in quantifying the anorectal angle and in the diagnosis of posterior pelvic floor disorders.

METHODS

Forty-three consecutive women with functional impairment of the posterior pelvic floor were enrolled after a clinical evaluation. Using both CCD and introital ultrasound examination, the anorectal angle was measured during squeezing to evaluate the strength of voluntary muscle contraction and during straining to assess pelvic floor relaxation. Rectocele depth and the presence of intussusception were assessed. The performance of CCD and that of introital ultrasound were compared.

RESULTS

Good concordance was obtained between introital ultrasound and CCD. The intraclass correlation coefficient was 0.82 (95% CI, 0.69-0.89) for measurement of the anorectal angle during squeezing and 0.67 (95% CI, 0.47-0.81) during straining. Rectoceles > 4 cm on CCD were detected by introital ultrasound in 100% of cases, and there was 91% agreement for rectal intussusception. Cohen's kappa index was moderate for rectocele assessment (0.41, P < 0.01) and excellent for intussusception (0.91, P < 0.001). It was also noted that introital ultrasound could be used to detect pelvic floor dyssynergia.

CONCLUSIONS

Introital ultrasound is a simple, accurate, non-invasive method with which to assess anorectal dynamics.

Simple ultrasound evaluation of the anal sphincter in female patients using a transvaginal transducer

OBJECTIVE

Fecal incontinence affects 0.2% of women aged 15-64 years and about 1.3% of women over 64 years. Most cases are related to instrumental deliveries affecting the anal sphincter complex. We propose a simple technique using the generally available transvaginal transducer to evaluate the anal sphincter complex.

METHODS

Ninety-two patients underwent ultrasound examination. Group I consisted of 53 nulliparous patients. In Group II there were six patients with normal spontaneous vaginal deliveries without episiotomies. In Group III there were 14 patients with vaginal deliveries and one to three episiotomies but no lacerations. In Group IV there were nine postpartum patients with recently repaired (48 h to 3 weeks) third- and fourth-degree lacerations. All women in Groups I-IV were asymptomatic. Group V consisted of 10 patients symptomatic for fecal incontinence. We used a vaginal probe (5-9-MHz) with the footprint placed in the fourchette pointing towards the anus in a transverse and then in a median (sagittal) plane. If seen, the combined internal and external anal sphincter thickness at the 12 o'clock location was measured. We visualized normal star-shaped mucosal folds on the transverse section and described the sonographic anatomy in both planes.

RESULTS

The mean sphincter thickness measured at 12 o'clock in Group I was 2.3 (range, 1.0-4.7) mm, in Group II it was 2.9 (range, 2.4-3.4) mm, and in Group III it was 2.3 (range, 1.0-3.7) mm. The differences between these three groups were not significant. Patients from Group IV showed thinning or discontinuous sphincter anatomy at the 12 o'clock position. All symptomatic patients from Group V showed abnormal sphincter anatomy, and the normal star-like appearance of the anal mucosa on the transverse section was deformed, radiating from the point of the sphincter damage. Four of the 10 patients in this group underwent surgical repair. In these patients the sonographic findings were confirmed.

CONCLUSIONS

The images obtained using this imaging modality show the sphincter muscle anatomy as well as the possible pathology. Due to its simplicity the technique can be applied in any place where a vaginal transducer is available.