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.

Sonographic postpartum anal sphincter defects and the association with pelvic floor pain and dyspareunia.

INTRODUCTION: Pelvic floor pain and dyspareunia are both important entities of postpartum pelvic pain, often concomitant and associated with perineal tears during vaginal delivery. The association between postpartum sonographic anal sphincter defects, pelvic floor pain, and dyspareunia has not been fully established. We aimed to determine the prevalence of postpartum anal sphincter defects using three-dimensional endoanal ultrasonography (3D-EAUS) and evaluate their association with symptoms of pelvic floor pain and dyspareunia. MATERIAL AND METHODS: This prospective cohort study followed 239 primiparas from birth to 12 months post delivery. Anal sphincters were assessed with 3D-EAUS 3 months postpartum, and self-reported pelvic floor function data were obtained using a web-based questionnaire distributed 1 year after delivery. Descriptive statistics were compared between the patients with and without sonographic defects, and the association between sonographic sphincter defects and outcomes were analyzed using logistic regression. RESULTS: At 3 months postpartum, 48/239 (20%) patients had anal sphincter defects on 3D-EAUS, of which 43 (18%) were not clinically diagnosed with obstetric anal sphincter injury at the time of delivery. Patients with sonographic defects had higher fetal weight than those without defects, and a perineum <2 cm before the suture was a risk factor for defects (odds ratio [OR], 6.9). Patients with sonographic defects had a higher frequency of dyspareunia (OR, 2.4), and pelvic floor pain (OR, 2.3) than those without defects. CONCLUSIONS: Our results suggest an association between postpartum sonographic anal sphincter defects, pelvic floor pain, and dyspareunia. A perineal height <2 cm, measured by bidigital palpation immediately postdelivery, was a risk factor for sonographic anal sphincter defect. We suggest offering pelvic floor sonography around 3 months postpartum to high- risk women to optimize diagnosis and treatment of perineal tears and include perineum <2 cm prior to primary repair as a proposed indication for postpartum follow-up sonography.

Clinical, ultrasonographic, and functional outcomes after obstetric anal sphincter injury primary repair: A single-center experience.

OBJECTIVE: To present clinical and instrumental sequelae after obstetric anal sphincter injuries (OASIS), evaluating correlations between intrapartum severity of lesions, postpartum symptoms, and sonographic and manometric findings; outcomes during subsequent deliveries were also evaluated. METHODS: This retrospective study evaluated all consecutive women who sustained an OASIS between 2015 and 2020. Postpartum symptoms, anorectal manometry (ARM), and three-dimensional endoanal ultrasonography (3D-EAUS) were analyzed. RESULTS: A total of 107 women underwent OASIS primary repair; 84 (78.5%) of them were asymptomatic after 1 month. The presence and severity of symptoms showed a great correlation with instrumental outcomes in terms of maximum resting pressure, squeeze pressure increment (SPI), circumferential extension of defect for both external anal sphincter (EAS) and internal anal sphincter (IAS), and EAS, IAS and total Starck scores. There was a significant correlation between ARM and 3D-EAUS findings, with the exception of SPI, for which the abnormalities were not predictable based on EAUS results. CONCLUSION: Both ARM and EAUS findings after OASIS are directly related to each other, and associated with symptoms. These instrumental tools may be useful for OASIS assessment and counseling.

Correlation of anorectal symptoms and endoanal ultrasound findings after obstetric anal sphincter injuries (OASIS).

INTRODUCTION: Obstetric anal sphincter injuries (OASIS) predispose to development of anorectal symptoms that affect women's quality of life. METHODS: A retrospective cohort study was conducted for all women with singleton vaginal deliveries who had a primary OASIS repair and attended the Postpartum Perineal Clinic between July 1st 2017 and December 31st 2020. This study was approved by the Research Ethics Board. The purpose of this study was (1) to determine correlation between endoanal ultrasound (EAUS) findings and anorectal symptoms quantified by the St. Mark's Incontinence Score (SMIS), (2) to determine the incidence of residual anal sphincter defects, and (3) to determine the rate of clinical overdiagnosis of OASIS. Pearson correlation coefficient was used to assess correlation between anorectal symptoms and EAUS findings. RESULTS: A total of 247 participants with clinical diagnosis of OASIS met the inclusion criteria. A 3rd-degree tear was identified in 126 (51.0%) and 4th-degree tear was identified in 30 (12.1%) participants. In participants with sonographic evidence of OASIS, there was a statistically significant weak positive correlation between the size of residual defect and SMIS for both external anal sphincter (EAS) (r = .3723, p < .0001) and internal anal sphincter (IAS) (r = .3122, p = .0180). Residual defect in the anorectal sphincter of greater than 1 hour (> 30°) in width was present in 64.3% participants with 3rd-degree tear and 86.7% participants with 4th-degree tear. The rate of overdiagnosis was 36.8%. CONCLUSION: The size of residual defect of EAS and IAS has a weak positive correlation with anorectal symptoms, emphasizing the importance of EAUS for counselling regarding mode of subsequent delivery.

Assessing Obstetric Anal Sphincter Injuries: A Comparison of Exoanal and Endoanal Ultrasound.

OBJECTIVES: To explore the differences in assessing obstetric anal sphincter injuries (OASI) between transperineal ultrasound (TPUS) and endoanal ultrasound (EAUS) and test relationships between ultrasound findings and anal incontinence (AI) symptoms. METHODS: A group of 196 women with a history of vaginal delivery was recruited. OASI was detected in a set of 5 slices by EAUS and 8 slices by TPUS. OASI grading was performed on TPUS rules and EAUS rules. A "significant sphincter defect" was diagnosed by TPUS and EAUS using "2/3 rules." Symptoms of AI were determined using the St Mark's Incontinence Score (SMIS). Ultrasound findings were compared between the two methods and correlated with symptoms. RESULTS: Of 196 women, 29 (14.8%) suffered from AI with a mean SMIS of 12.1 ± 4.5, and 70 (35.7%) women with a mean age of 57 years had suspected OASI on imaging. Twenty-one (10.7%) "significant defects" were diagnosed by TPUS and 24 (12.2%) by EAUS. OASI Grades on TPUS had good agreement with EAUS rules (k = 0.70, P < .001). Logistic regression analysis showed that OASI Grade on imaging and "significant sphincter defects" seen on both forms of imaging were associated with AI symptoms. The odds ratio was 46 and 38 for "significant defects" on TPUS and EAUS, and 14 and 7 for OASI 3b+ on TPUS and EAUS in predicting AI, respectively. CONCLUSIONS: "Significant defects" diagnosed by EAUS or TPUS and OASI Grade 3b+ predict AI symptoms. The diagnostic performance of endoanal and exoanal ultrasound (EAUS and TPUS) appear to be very similar.

The Functional Luminal Imaging Probe (FLIP): A Good Tool for Adjustment of anal Canal Dimensions During Operative Management of Fecal Incontinence.

PURPOSE: Fecal incontinence is a troublesome problem in the field of colorectal surgery. The main aim of this study was to adjust the anal canal resistance during operative management of anal incontinence using Endo-FLIP. METHODS: This was a prospective cohort study held at Cairo university hospital. Hundred forty-eight incontinent patients treated by different surgical procedures were included. During the procedure the Endo-FLIP was applied to adjust the anal canal dimensions (ACL and ACD) so the ACR could be adjusted based on the flow equation. These were also assessed pre-operatively with Endo-FLIP system and the flow equation calculator. The clinical severity of the disease and outcome after surgical procedures were assessed and correlated to the physiologic parameters. RESULTS: ACL, ACD and ACR had had significant correlations to the degree of incontinence (P < .001). ACL, ACD and ACR showed statistically significant change with primary repair and gluteus maximus transposition operations. After treatment of fecal incontinence, in good responders' group, the mean resting anal canal resistance increased significantly to 4649.05 ± 1161.49 (postoperative) while in poor responders' group it was 1919.9 ± 1077.73. CONCLUSIONS: The Endo-flip can be used to measure the anal canal geometric parameters (ACL and ACD) and then anal canal resistance could be calculated by the flow equation - pre-and post-operatively- which help the adjustment of the surgical repair of sphincter injury in fecal incontinence patients which may improve the surgical outcome.

Underdiagnosis of internal anal sphincter trauma following vaginal delivery.

OBJECTIVE: Damage to the anal sphincter during childbirth remains the leading cause of fecal incontinence in women. Defects in the internal (IAS) or external anal sphincter, alongside symptoms and sphincter tone, will generally dictate the suggested mode of delivery in any successive pregnancy. This study aimed to examine using endoanal ultrasonography the prevalence of IAS damage in women referred with Grade-3a or -3b obstetric anal sphincter injury (OASI) in a tertiary-referral perineal clinic. METHODS: This was a retrospective observational study of all women referred to a tertiary-referral perineal clinic after primary repair of OASI (Grade 3a-c, 4) diagnosed for the first time following vaginal delivery between January 2016 and December 2019, inclusive. Women were assessed using the Wexner bowel continence questionnaire, digital examination of sphincter tone and endoanal ultrasound. Injuries in each sphincter were classified as a scar (≤ 30°) or defect (> 30-90° or > 90°) on endoanal imaging in the axial plane. RESULTS: In total, 615 women were referred following primary repair of OASI. Sonographic evidence of damage to the IAS was seen in 9.1% (46/506) of women diagnosed with a Grade-3a/3b injury. In women referred with a Grade-3a/3b tear, symptom scores were statistically higher (P = 0.025) in those with an IAS defect > 30° compared to those with an intact or scarred IAS, although the median score was zero in both groups. The proportion of women in each group with severe symptoms (score > 9) was similar (2.6% vs 6.5%; P = 0.148). Among women referred with a Grade-3a/3b tear, sphincter tone was reduced more frequently in those with a defect of the IAS than in those with an intact or scarred IAS (52.2% vs 11.7%; odds ratio, 8.14 (95% CI, 4.26-15.67); P < 0.001). Regardless of the reason for referral, women with reduced sphincter tone on rectal examination were four times as likely to have had an IAS defect > 30° than were those with normal resting tone (risk ratio, 4.58 (95% CI, 3.25-6.45); P < 0.001). CONCLUSIONS: One in 11 women diagnosed with a Grade-3a or -3b tear have evidence of damage to their IAS on endoanal ultrasound. Damage to this muscle is linked to fecal incontinence in women and can have a significant impact on the planning of any future deliveries. This study highlights the importance of established perineal clinics with access to ultrasound. Nonetheless, if reduced sphincter tone is felt on rectal examination, a clinician should have a high index of suspicion for an occult IAS injury. © 2022 The Authors. Ultrasound in Obstetrics & Gynecology published by John Wiley & Sons Ltd on behalf of International Society of Ultrasound in Obstetrics and Gynecology.

Is posterior compartment prolapse associated with anal incontinence?

OBJECTIVE: It has been claimed that manifestations of posterior compartment prolapse, such as rectocele, enterocele and intussusception, are associated with anal incontinence (AI), but this has not been studied while controlling for anal sphincter trauma. We aimed to investigate this association in women with intact anal sphincter presenting with pelvic floor dysfunction. METHODS: This retrospective study analyzed 1133 women with intact anal sphincter presenting to a tertiary urogynecological center for pelvic floor dysfunction between 2014 and 2016. All women underwent a standardized interview, including assessment of symptoms of AI, clinical examination and three-/four-dimensional transperineal ultrasound. Descent of the rectal ampulla, true rectocele, enterocele, intussusception and anal sphincter trauma were diagnosed offline. RESULTS: Mean age was 54.1 (range, 17.6-89.7) years and mean body mass index was 29.4 (range, 14.7-67.8) kg/m2 . AI was reported by 149 (13%) patients, with a median St Mark's anal incontinence score of 12 (interquartile range, 1-23). Significant posterior compartment prolapse was seen in 693 (61%) women on clinical examination. Overall, 638 (56%) women had posterior compartment prolapse on imaging: 527 (47%) had a true rectocele, 89 (7.9%) had an enterocele and 26 (2.3%) had an intussusception. Women with ultrasound-diagnosed enterocele had a significantly higher rate of AI (23.6% vs 12.3%; odds ratio (OR), 2.21 (95% CI, 1.31-3.72); P = 0.002), but when adjusted for potential confounders, this association was no longer significant (OR, 1.56 (95% CI, 0.82-2.77); P = 0.134). CONCLUSION: In women without anal sphincter trauma, posterior compartment prolapse, whether diagnosed clinically or by imaging, was not shown to be associated with AI. © 2022 International Society of Ultrasound in Obstetrics and Gynecology.

Effect of posture on anorectal manometric measurements in female patients with fecal incontinence and rectoanal intussusception.

PURPOSE: This study aimed to investigate the influence of erect position on anorectal manometry in patients with rectoanal intussusception (RAI). METHODS: This was a single center prospective observational study. Eighty female patients with fecal incontinence (FI) who underwent defecography between 1st January 2016 and 30th April 2022 were included. The effect of posture on commonly measured parameters during manometry was assessed in the left-lateral and erect positions. The severity of FI was assessed using FI Severity Index (FISI). RESULTS: Defecography showed that 30 patients had circumferential RAI (CRAI), and 50 had non-CRAI. There were no significant differences in age, parity, FI type, and FISI scores between the groups. However, FISI scores were significantly lower in 51 patients with passive FI than 12 patients with mixed FI type [21 (8-38) vs. 32 (8-43), P = 0.007]. Endo-anal ultrasound showed no significant difference in the incidence of sphincter defects between the groups. Maximum squeeze pressure was significantly lower in the erect position than in the left-lateral position in the CRAI patients [119 cm H2O (59‒454 cm H2O) vs. 145 cm H2O (65‒604 cm H2O), P = 0.006] however, this finding was not observed in the non-CRAI group and the subgroup of anterior RAI patients. In either group, maximum resting pressure, defecation desire volume, and maximum tolerated volume were significantly higher, while anal canal length was significantly shorter in the erect position than in the left-lateral position, respectively. CONCLUSION: Voluntary contraction in female FI patients with CRAI was suppressed in the erect position.

When to assess residual anal sphincter defect after OASI by ultrasound.

OBJECTIVES: Obstetrical anal sphincter injuries (OASIS) are complications of vaginal delivery. Unrepaired anal sphincter after delivery increases the risk of anal incontinence. The aim of our study is to search for residual defect after OASI repair by 4D introital ultrasound (US). We hypothesised that imaging prior to hospital discharge would show the same number of defects as assessment at 3 months. STUDY DESIGN: This is a retrospective analysis of 138 patients with immediate repair after OASIS. Since 2009, we have been routinely inviting all our patients with OASIS to the perineal clinic for postoperative follow-up. We scheduled the first visit before discharge from hospital and followed up with a second visit after three months. During both visits, patients underwent transperineal 4D ultrasound examination. We provided examination while at rest and during contraction; volumes were saved for further evaluation. RESULTS: Eighty-one patients (58.7%) completed both exams and were included in the analysis. Residual external anal sphincter defect was found in 17.3% at the first visit versus 13.6% at the second (delayed) visit. We were not able to assess the sphincter in 9.9% at early versus none in the delayed examination. In 9.9%, the residual defect was not confirmed by the second examination, and in 4.9% the residual defect was missed by the first examination. CONCLUSIONS: In conclusion, we have found that a 3 month scan yields a smaller number of defects than a scan before discharge.

Can transperineal ultrasound improve the diagnosis of obstetric anal sphincter injuries?

INTRODUCTION AND HYPOTHESIS: Women with missed obstetric anal sphincter injuries (OASIs) are at an increased risk of anal incontinence. Our aim was to assess the accuracy of three-dimensional (3D) transperineal ultrasound (TPUS) compared with clinical examination for detecting OASIs. METHODS: A cross-sectional study of women undergoing their first vaginal delivery. Perineal trauma was initially assessed by the doctor or midwife performing the delivery (accoucheur) and women were then re-examined by the trained research fellow (KW). A 3D TPUS was performed immediately after delivery before suturing to identify OASIs. The research fellow's clinical diagnosis was used as the reference standard. A power calculation determined that 216 women would be required for the study. RESULTS: Two hundred and sixty-four women participated and 226 (86%) delivered vaginally. Twenty-one (9%) sustained OASIs. Six (29%) of these tears were missed by the accoucheur but were identified by the research fellow. TPUS identified 19 of the 21 (90.5%) OASIs. One percent (n = 2) had sonographic appearances of an anal sphincter defect that was not seen clinically. The positive and negative predictive value of TPUS to detect OASIs was 91% and 99% respectively. TPUS identified 91% of OASIs compared with 71% detected by the accoucheur, which was not statistically significant. CONCLUSIONS: The detection rate of OASIs with TPUS and with the clinical findings of the accoucheur was similar. Given the training and financial implications needed for TPUS, attention needs to be focused on the training of midwives and doctors to identify anal sphincter injuries by clinical examination.

Obstetric anal sphincter injuries (OASIS): using transperineal ultrasound (TPUS) for detecting, visualizing and monitoring the healing process.

PURPOSE: The aim of this study was to examine whether OASIS, and its extent, can be confirmed or excluded using transperineal ultrasound (TPUS). A further objective of this study was to monitor the healing process over a period of 6 months and to establish a connection between the sonographic appearance of obstetric anal sphincter injury (OASIS) and anal incontinence. MATERIALS AND METHODS: In this retrospective clinical study, women with OASIS who gave birth between March 2014 and August 2019 were enrolled. All the patients underwent TPUS 3 days and 6 months after delivery. A GE E8 Voluson ultrasound system with a 3.5-5 MHz ultrasound probe was used. The ultrasound images showed a third-degree injury, with the measurement of the width of the tear and its extent (superficial, partial, complete, EAS and IAS involvement). A positive contraction effect, a sign of sufficient contraction, was documented. Six months after delivery, a sonographic assessment of the healing (healed, scar or still fully present) was performed. A Wexner score was obtained from each patient. The patients' medical histories, including age, parity, episiotomy and child's weight, were added. RESULTS: Thirty-one of the 55 recruited patients were included in the statistical evaluation. Three patients were excluded from the statistical evaluation because OASIS was excluded on TPUS 3 days after delivery. One patient underwent revision surgery for anal incontinence and an inadequately repaired anal sphincter injury, as shown sonographic assessment, 9 days after delivery. Twenty patients were excluded for other reasons. The results suggest that a tear that appears smaller (in mm) after 3 days implies better healing after 6 months. This effect was statistically significant, with a significance level of alpha = 5% (p = 0.0328). Regarding anal incontinence, women who received an episiotomy had fewer anal incontinence symptoms after 6 months. The effect of episiotomy was statistically significant, with a significance level of alpha = 5% (p = 0.0367). CONCLUSION: TPUS is an accessible, non-invasive method for detecting, quantifying, following-up and monitoring OASIS in patients with third-degree perineal tears. The width, as obtained by sonography, is important with regard to the healing of OASIS. A mediolateral episiotomy seems to prevent anal incontinence after 6 months.

Fecobionics characterization of female patients with fecal incontinence.

Defecatory disorders including fecal incontinence (FI) are diagnosed on the symptom pattern supplemented by anorectal manometry (ARM), the balloon expulsion test (BET), and endo-anal ultrasonography. In this study, we used a simulated stool named Fecobionics to study distinct defecation patterns in FI patients using preload-afterload diagrams and to provide comparative data on defecation indices (DIs) between passive and urge incontinent patients. All subjects had Fecobionics, endo-anal ultrasonography and ARM-BET done. The Fecobionics bag was distended in rectum until urge in 37 female patients (64.1 ± 1.5 yrs) and a group of normal subjects (NS, 12F, age 64.8 ± 2.8 yrs). Rear-front pressure (preload-afterload) diagrams and DIs were compared between groups. The FISI score in the patients was 8.6 ± 0.6. The NS did not report FI-related symptoms. All patients and NS defecated Fecobionics and ARM-BET within 2 min. The urge volume was 46.1 ± 3.6 and 35.3 ± 5.9 mL in the FI and normal groups (P > 0.1). The expulsion duration was 14.8 ± 2.4 and 19.8 ± 5.1 s for the two groups (P > 0.1). The preload-afterload diagrams demonstrated clockwise loops that clearly differed between the FI subtypes and NS. The DIs showed profound difference between patients and NS. Fecobionics data showed higher correlation with symptoms in FI patients than ARM-BET. Fecobionics obtained novel pressure signatures in subtypes of FI patients and NS. Fecobionics provides DI data that cannot be obtained with ARM-BET.

Relationship between anal functional lumen imaging probe (EndoFLIP®) results and the clinical presentation of faecal incontinence.

AIM: Faecal incontinence (FI) subtypes (urge, passive, mixed) are linked to the physiopathological mechanism of FI. Previous studies have failed to demonstrate a consistent relationship between FI subtype and anal sphincter dysfunction. Our aim was to evaluate the relationship between anal sphincter function, assessed using the new EndoFLIP® technology, and FI subtype. METHOD: Patients referred for FI were prospectively enrolled between October 2015 and May 2021 in a registry, and data were retrospectively examined. Each patient underwent a clinical assessment as well as three-dimensional high-resolution or water-perfused anorectal manometry, anal EndoFLIP®, and anorectal electrophysiological and endoanal ultrasound tests. The results of the investigations were compared across FI subtypes. RESULTS: The cohort included 133 patients, 54 (41%) of whom met the criteria for urge FI, 40 (30%) for passive FI and 39 (29%) for mixed FI. The resting anal distensibility index (DI) at 50 ml of distension was significantly lower in patients with urge FI than in patients with passive FI (p = 0.04). At rest, a DI at 50 ml of distension ≥7.3 mm2  mmHg-1 and a DI at 40 ml of distension <1.3 mm2  mmHg-1 were associated with the passive and urge FI subtypes, respectively, with poor discriminatory power (an accuracy of 0.49 compared with 0.33 for random assignment). There were no differences in anorectal manometry, endoanal ultrasound or electrophysiological test results among the urge, passive and mixed FI subgroups (all p > 0.05). CONCLUSION: The anal sphincter DI using the EndoFLIP® system displayed poor predictive performance in distinguishing among FI subtypes.

The influence of the fundal pressure manoeuvre at delivery on the anal sphincter injury diagnosed with endoanal ultrasonography.

OBJECTIVES: The fundal pressure manoeuvre (FPM) is a procedure where the fundus of the uterus is pushed through the abdominal wall by the midwifes and doctors to shorten the terminal phase of the second stage vaginal delivery. Nowadays its use is controversial and associated with many adverse effects. The aim of the study was to evaluate benefits and adverse maternal outcomes after FPM. The correlation of the FPM with episiotomy was evaluated. The role of the FPM on pelvic floor dysfunction such as anal incontinence due to anal sphincter injury was assessed. STUDY DESIGN: The retrospective study was conducted between 2017 and 2021. The women who came to the postpartum examination to Gynaecology department for various reasons and gave vaginal birth to a singleton were included in the study. The women who had instrumental delivery were excluded. Minimal sample size was calculated with calculator.net and set on 45. Two groups were formed one with fundal pressure and one without, 96 and 90 patients respectively. The maternal, fetal, and obstetric factors that could be associated with the application of FPM were examined. The endoanal ultrasound examination was performed on all women included in the study. RESULTS: The study did not show that FPM would lead to a more frequent occurrence of anal sphincter injury (p = 0.73), effect its location (p = 0.77) and depth (p = 0.97), however the test group tended to have longer ruptures compared to control group (p = 0.1). No statistically significant differences in episiotomies between control and test group (p = 0.075) were shown. Endoanal ultrasound showed discrepancy between clinically stated and ultrasonographical diagnoses of anal sphincter injuries. In 61,3% of patients with anal sphincter injury after FPM, reported one of the anal incontinence problems of varying degrees six months after delivery. CONCLUSION: Given that the study proved that FPM is not correlated to the anal sphincter injury it can be used safely. The FPM should be performed carefully and only if necessary to safely finish the labour or in combination with instrumental delivery.

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.

Anorectal Anatomy and Function.

Anatomy of pelvic floor muscles has long been controversial. Novel imaging modalities, such as three-dimensional transperineal ultrasound imaging, MRI, and diffusion tensor imaging, have revealed unique myoarchitecture of the external anal sphincter and puborectalis muscle. High-resolution anal manometry, high-definition anal manometry, and functional luminal imaging probe are important new tools to assess anal sphincter and puborectalis muscle function. Increased understanding of the structure and function of anal sphincter complex/pelvic floor muscle has improved the ability to diagnose patients with pelvic floor disorders. New therapeutic modalities to treat anal/fecal incontinence and other pelvic floor disorders will emerge in the near future.

Under-classified obstetric anal sphincter injuries.

INTRODUCTION AND HYPOSTHESIS: Obstetric anal sphincter injuries (OASIs) that are missed at delivery can have long-term consequences. OASIs that are under-classified at delivery are likely to be inadequately repaired, resulting in a persistent anal sphincter defect. We aimed to identify women who have persistent defects on endoanal ultrasound, inconsistent with the original diagnosis, and compare the effect on St Mark's incontinence scores (SMIS). We also aimed to look for changes in numbers of under-classification over time. METHODS: Records of women attending a perineal clinic who had endoanal ultrasound from 2012 to 2020 were reviewed. Women who had a modified Starck score implying a defect greater than the classification [indicated by the depth of external anal sphincter or internal anal sphincter (IAS) defect] at delivery were identified. RESULTS: A total of 1056 women with a diagnosis of 3a or 3b tears were included. Of these, 120 (11.36%) were found to have a defect greater than the original diagnosis and therefore were incorrectly classified at delivery. Women who had a 3b tear diagnosed at delivery, but had an IAS defect, had a significantly higher SMIS (p < 0.01). When comparing two 4-year periods, there was a significant improvement in the diagnosis of IAS tears. CONCLUSION: Some women with OASIs that have under-classified OASIs are associated with worse anorectal symptoms. This is likely because of an incomplete repair. Some improvement in diagnosis of IAS tears has been noted. We propose improved training in OASIs can help reduce the number of incorrectly classified tears and improve repair.

Anal endosonographic assessment of the accuracy of clinical diagnosis of obstetric anal sphincter injury.

INTRODUCTION AND HYPOTHESIS: Obstetric anal sphincter injuries (OASIS) are a common cause of maternal morbidity with an overall incidence in the UK of 2.9% (range 0-8%). They can cause a range of physical symptoms and psychological distress. This study aims to assess the accuracy of clinical diagnosis of OASIS using endoanal ultrasound (EAUS) and the correlation between confirmed injury and change to anorectal physiology squeeze pressure and the incidence of bowel symptoms. METHODS AND MATERIALS: Retrospective study of prospectively collected data from 1135 women who attended the Third- and Fourth-Degree Tears Clinic at our institution, 12 weeks post-delivery, between June 2008 and October 2019. RESULTS: OASIS was confirmed in 876 (78.8%) women and 236 (21.3%) had no injury. Of the women who underwent anorectal physiology, 45.6% had a mean maximal resting pressure below the normal range and 68.8% had a mean incremental squeeze pressure below normal. Women with confirmed OASIS had significantly lower pressures (p < 0.001) than those without a confirmed sphincter injury. Three hundred ninety-three (34.8%) women reported bowel symptoms, with those with endosonographic evidence of injury more likely to develop flatus incontinence. CONCLUSION: Of the women in this study with a suspected OASIS, 21.2% could be reassured that they did not have an injury. This information is useful for women considering future mode of delivery. Those with confirmed injury are more likely to complain of flatus incontinence and have reduced anal sphincter pressures.