Risk factors and outcome of repair of obstetric anal sphincter injuries as followed up in a dedicated perineal clinic

A Postpartum Perineal Clinic in Nova Scotia: Characteristics Associated With Attendance and Its Association With Recurrent Obstetrical Anal Sphincter Tears

OBJECTIVES

The Healthy Recovery after Childbirth Clinic (HRCC) in Nova Scotia provides postpartum care to patients who experience obstetric anal sphincter injuries (OASIS). The purpose of this study was to describe characteristics associated with HRCC attendance, characteristics associated with a trial of labour in a subsequent delivery, and OASIS recurrence by HRCC attendance status.

METHODS

A retrospective cohort study using the Atlee Perinatal Database and clinical record review included primiparous individuals who sustained an OASIS at IWK Health in Halifax between 2013 and 2020. The χ2 and Fisher exact tests were performed to compare groups.

RESULTS

Of the 1041 individuals included, 67% attended HRCC. Attendance increased from 58% in 2013-2015 to 77% in 2019-2020. Younger age (<25 years) and smoking were associated with lower HRCC attendance (P = 0.07 and <0.01, respectively). Other characteristics, including area-level income and driving distance to HRCC, were not associated with attendance (P > 0.05). Of the 439 individuals who had a subsequent delivery, 92% had a trial of labour. Individuals with fourth-degree injury were less likely to attempt a trial of labour than those with third-degree injury (73% vs. 94%, P < 0.01). Of those who delivered vaginally, OASIS recurrence was similar in those who did and did not attend the HRCC (7.5% vs. 6.5%, P = 0.84).

CONCLUSIONS

HRCC attendance was high, but the disparity by age and smoking status suggests some barriers to access that should be explored. Although we found no difference in OASIS recurrence by HRCC attendance, more research with larger samples with adjustment for confounders is needed.

Anal incontinence following obstetric anal sphincter injury: Is there a difference between subtypes? A systematic review

AIMS

Obstetric anal sphincter injury (OASI) is associated with long-term anal incontinence (AI). We aimed to address the following questions: (a) are women with major OASI (grade 3c and 4) at higher risk of developing AI when compared to women with minor OASI (grade 3a and 3b)? (b) is a fourth-degree tear more likely to cause AI over a third-degree tear?

METHODS

A systematic literature search from inception until September 2022. We considered prospective and retrospective cohort studies, cross-sectional and case-control studies without language restrictions. The quality was assessed by the Newcastle-Ottawa Scale and the Joanna Briggs Institute critical appraisal checklist. Risk ratios (RRs) were calculated to measure the effect of different grades of OASI.

RESULTS

Out of 22 studies, 8 were prospective cohort, 8 were retrospective cohort, and 6 were cross-sectional studies. Length of follow-up ranged from 1 month to 23 years, with the majority of the reports (n = 16) analysing data within 12-months postpartum. Third-degree tears evaluated were 6454 versus 764 fourth-degree tears. The risk of bias was low in 3, medium in 14 and high in 5 studies, respectively. Prospective studies showed that major tears are associated with a twofold risk of AI for major tears versus minor tears, while retrospective studies consistently showed a risk of fecal incontinence (FI) which was two- to fourfold higher. Prospective studies showed a trend toward worsening AI symptoms for fourth-degree tears, but this failed to reach statistical significance. Cross-sectional studies with long-term (≥5 years) follow-up showed that women with fourth-degree tear were more likely to develop AI, with an RR ranging from 1.4 to 2.2. Out of 3, 2 retrospective studies showed similar findings, but the follow-up was significantly shorter (≤1 year). Contrasting results were noted for FI rates, as only 5 out of 10 studies supported an association between fourth-degree tear and FI.

CONCLUSIONS

Most studies investigate bowel symptoms within few months from delivery. Data heterogeneity hindered a meaningful synthesis. Prospective cohort studies with adequate power and long-term follow-up should be performed to evaluate the risk of AI for each OASI subtype.

The incidence of anal incontinence following obstetric anal sphincter injury graded using the Sultan classification: a network meta-analysis

OBJECTIVE

This study aimed to systematically determine and compare the incidence of anal incontinence between those with different grades of obstetric anal sphincter injury.

DATA SOURCES

Ovid MEDLINE, Embase, and the Cochrane Library were searched from January 2000 to April 2021.

STUDY ELIGIBILITY CRITERIA

Observational studies investigating the incidence of anal incontinence following an obstetric anal sphincter injury that was graded using the Sultan classification were eligible for inclusion. To allow comparison between individual tear grades (3a, 3b, 3c, fourth), a network meta-analysis was performed using Stata (version 15.1).

METHODS

For binary outcomes, odds ratios with corresponding 95% confidence intervals were reported. Obstetric anal sphincter injury grades were ranked from the best clinical outcome to the worst clinical outcome. The percentage chance of each grade taking each rank with regards to outcome was calculated. Study quality and risk of bias was assessed using the relevant tool from the Joanna Briggs Institute.

RESULTS

Of the 696 studies identified, 10 were eligible for inclusion and were included in the network meta-analysis (n=2467 women). The mean incidence of anal incontinence among those with 3a tears was 22.4% (range, 6.1%-51.2%), 24.9% (range, 6.9%-46.7%) among those with 3b tears, 26.8% (range, 0%-55.6%) among those with 3c tears, and 28.6% (0%-71.4%) among those with fourth-degree tears. Anal incontinence incidence was found to be significantly higher among those with 3c (odds ratio, 1.79; 95% confidence interval, 1.09-2.94) and fourth-degree tears (odds ratio, 2.37; 95% confidence interval, 1.40-4.02) than among those with 3a tears. In addition, anal incontinence incidence was significantly higher among those with fourth-degree tears (odds ratio, 1.89; 95% confidence interval, 1.10-3.22) than among those with 3b tears. Those with 3a tears had the highest probability of having the best clinical outcome; those with 3b; second-, 3c; third- and fourth-degree tears had the highest probability of having the worst clinical outcome. Overall, all studies had a high or unclear risk of bias across 1 or more assessed element.

CONCLUSION

This was a network meta-analysis comparing the incidence of anal incontinence among those with different grades of obstetric anal sphincter injury. Increasing tear-grade severity is associated with worse clinical outcomes. This study provides useful, clinically applicable information that can assist clinicians in the counseling of women following an obstetric anal sphincter injury. In addition, it highlights the importance of accurately diagnosing the obstetric anal sphincter injury grade and subsequently performing the appropriate repair.

Short and long term results of anatomical reconstruction of perineal body and sphincter complex in obstetric anal sphincter injuries

OBJECTIVES

The effective way to reduce the risk of fecal incontinence (FI) in primary repaired obstetric anal sphincter injuries (OASIS) patients is to accurately detect the injury and provide complete anatomical reconstruction. The aim of the study was to evaluate the short-term and long-term results of OASIS cases that were diagnosed by an experienced surgical team and whose perineal body and anal sphincters were reconstructed separately.

MATERIAL AND METHODS

Sixteen patients that required consultations due to anal sphincter damage during vaginal delivery and underwent anatomical reconstruction due to Grade 3c and Grade 4 sphincter damage between 2007 and 2019 were included in the study. These cases were divided into three groups [Group 1 (≤12 months), Group 2 (12-60 months), Group 3 (≥60 months)] according to the time elapsed until anal manometry, and incontinence questionnaires were conducted in the postoperative period. Recto-anal inhibitory reflex (RAIR), mean resting (IB) and squeezing (SB) pressures were measured by anal manometry. Anal incontinence (AI) and FI rates were determined by questionnaires. Anal sphincter damage repair techniques (overlapping, end-to-end) were determined. These parameters were compared between the three groups.

RESULTS

Mean age of the patients was 27.5 (16-35) years. Six (37.5%) patients had Grade 3c, while 10 (62.5%) had Grade 4 injury. The overall mean RP and SP were 35 (26-56) mmHg and 67 (31-100) mmHg, respectively. Mean RP and SP were 46/67 mmHg, 33.5/75.5 mmHg, and 37.5/70.5 mmHg in Groups 1, 2, and 3 respectively. There was no difference between the three groups in terms of mean RP and SP (p= 0.691, p= 0.673). The rate of AI and FI in all patients were 18.75% and 12.5%, respectively while the rate of severe AI incontinence was 6%. Severe AI was observed in 1 (16.7%) case in Group 1, mild AI was observed in 1 (25%) case in group 2, and in 1 (16.7%) case in Group 3. RAIR was positive in all patients. In Group 1, 5 (83.3%) patients underwent overlapping repair, and in Group 3, 6 (100%) patients underwent end-to-end repair. This difference was statistically significant (p= 0.011).

CONCLUSION

In vaginal births, evaluation of anal sphincter damage, determination of perineal body structures and anal sphincters separately and performing anatomical reconstruction when needed significantly reduce the rate of FI in the short and long term.

Association between birth weight and head circumference and obstetric anal sphincter injury severity

OBJECTIVE

To identify risk factors for increasing severity of OASI and evaluate its possible correlation with two known risk factors-birth weight (BW) and neonatal head circumference (HC).

METHODS

We performed a retrospective cohort study at a university affiliated hospital between 2003 and 2019. We compared five groups of patients - according to presence and degree of perineal laceration - 3a, 3b, 3c and 4 and patients without OASI. Additionally, four parameters were defined to assess their relation to the severity of OASI: (1) BW ≥ 90th and HC < 90th percentiles; (2) BW < 90th and HC ≥ 90th percentile; (3) BW and HC ≥ 90th percentile and (4) BW and HC < 90th percentiles.

RESULTS

During the study period, 150,221 deliveries were evaluated. Parturients were allocated according to OASI severity - 455 patients had a 3rd (3a, 3b or 3c) or 4th degree perineal tear, while 110,966 patients had no OASI. Allocation to subgroups according to offspring anthropomorphic measures showed that as fetal size parameters increased, the rate of more severe tears increased, particularly in women delivering neonates with HC ≥ 90th percentile. Multinomial regression analysis was performed for each 3rd degree OASI subgroup. This analysis demonstrated the odds for OASI gradually increase with tear severity for BW ≥ 90th percentile and the combined BW and HC ≥ 90th percentile parameters, as compared with neonates with HC and BW < 90th percentile.

CONCLUSIONS

Birth weight and head circumference above the 90th percentile are correlated with increased degree of OASI severity.

Risk Factors in Third and Fourth Degree Perineal Tears in Women in a Tertiary Centre: An Observational Ambispective Cohort Study

Objectives: To analyze the main risk factors associated with third and fourth degree postpartum perineal tears in women attended to in our obstetrics service. Methods: An observational, retrospective, hospital cohort study was carried out in women whose deliveries were attended to in the obstetrics service of the Hospital General Universitario Gregorio Marañón de Madrid (HGUGM), during the period from January 2010 to April 2017. Results: During the study period, a total of 33,026 patients were included in the study. For maternal variables, the associated increased risk of severe perineal tearing in nulliparous women is OR = 3.48, for induced labor OR = 1.29, and for instrumental delivery by forceps OR = 4.52 or spatulas OR = 4.35; for the obstetric variable of episiotomy, it is OR = 3.41. For the neonatal variables, the weight of the newborns has a directly proportional relationship with the risk of severe tears, and for birth weights of 3000 g (OR = 2.41), 3500 g (OR = 1.97), and 4000 g (OR = 2.17), statistically significant differences were found in each of the groups (p < 0.05). Conclusion: Primiparity, induction of labor, episiotomy, instrumental delivery with forceps or spatula, and a birth weight of 3000 g or more are significantly associated with an increased risk of third and fourth degree perineal tears.

Molecular Effects of Topical Estrogen on Vaginal Granulation Tissue in Postpartum Women

OBJECTIVE

The aims of this study were to evaluate the biomolecular properties of vaginal and perineal granulation tissue in postpartum women and assess the potential impact of vaginal estrogen application.

METHODS

We prospectively identified women referred to a subspecialty peripartum clinic between September 2016 and April 2018 who developed symptomatic perineal or vaginal granulation tissue. As part of routine clinical care, granulation tissue was excised from each participant by a urogynecologist and subjected to RNA extraction, real-time quantitative polymerase chain reaction, histologic evaluation, and immunohistochemistry. Serum steroid hormone levels were measured. Comparisons were made between participants who used topical vaginal estradiol (E2) and those who did not (non-E2 controls).

RESULTS

Sixteen postpartum women were recruited for this pilot study. More than 30% of patients (n = 5, 31%) had used topical vaginal estradiol (E2) during their postpartum recovery. Histological appearance of granulation tissue evaluated by hematoxylin and eosin staining was similar in women treated with vaginal E2 and non-E2 controls. Both estrogen receptor α (ERα) and ERβ mRNA and ERα protein were readily detectable in the granulation tissue of E2-treated women. Although not statistically significant, participants who used topical E2 developed granulation tissue that exhibited local estrogen-responsive gene upregulation. Serum levels of estrone, E2, dehydroepiandrosterone, progesterone, and testosterone did not differ between vaginal E2-treated patients and controls.

CONCLUSIONS

Estrogen receptor α seems to be the predominant receptor mediating estrogen action in postpartum perineal and vaginal granulation tissue. Vaginal E2 use does not seem to affect serum levels of estrone, E2, dehydroepiandrosterone, progesterone, and testosterone in postpartum women.

Obstetric anal sphincter injury following previous vaginal delivery

INTRODUCTION AND HYPOTHESIS

Obstetric anal sphincter injury (OASI) is a debilitating complication of vaginal delivery. The aim of this study was to identify risk factors for OASI in women with a previous vaginal delivery. We further attempted to detect specific risk factors for severe OASI in this subgroup.

METHODS

We conducted a retrospective cohort study between 2003 and 2019. The study group included women who had a singleton, live, vertex, vaginal delivery at term and who also had at least one previous vaginal delivery. The control group included women with at least one previous vaginal delivery without OASI. General medical history, obstetric history, and ante-, intra- and post-partum data were collected and compared between groups.

RESULTS

Following implementation of the inclusion criteria, 79,176 women were included. Allocation to study groups was according to OASI occurrence: 135 patients (0.2%) had a third- or fourth-degree perineal tear, while 79,041 patients (99.8%) had no such injury. Multivariate analysis revealed that one previous vaginal delivery, birthweight ≥ 3900 g (90th percentile), vacuum-assisted vaginal delivery and episiotomy were associated with increased risk of OASI. Comparison of more severe OASI (3C and 4th-degree) cases to the control group showed similar results with the addition of prolonged second stage and younger age to risk factors associated with severe OASI while episiotomy was no longer significant.

CONCLUSION

In women with a previous vaginal delivery, one vs. two or more previous vaginal deliveries, increased birthweight, vacuum-assisted vaginal delivery and episiotomy are risk factors for OASI.

Residual Defects of the Anal Sphincter Complex Following Primary Repair of Obstetrical Anal Sphincter Injuries at a Large Canadian Obstetrical Centre

OBJECTIVES

To determine the rates of residual anal sphincter defect following primary repair of obstetrical anal sphincter injury (OASIS), and to assess symptomatology in these patients.

METHODS

A retrospective observational study of patients who underwent primary repair of an OASIS sustained at Mount Sinai Hospital from January 2016 to June 2017. Records were reviewed for demographic and obstetrical data, symptoms of anal incontinence (AI), and the results of endoanal ultrasonography (EA-US).

RESULTS

One hundred and one women sustained an OASIS during the study period, of whom 53 had EA-US performed at Mount Sinai Hospital; 4 women were excluded from this analysis. There were 42 third-degree tears and 7 fourth-degree tears. EA-US revealed residual defects in 22 patients with third-degree tears and 5 patients with fourth-degree tears (52% vs. 71%; P = 0.44).  Twelve patients with third-degree tears and 4 patients with fourth-degree tears reported AI (29% vs. 57%; P = 0.20). EA-US revealed no evidence of a tear in 14 patients clinically diagnosed with third-degree tears and 1 patient clinically diagnosed with a fourth-degree tear (33% vs. 14%).

CONCLUSION

These data demonstrate deficiencies in diagnosis and repair of OASIS. Continued training for health care providers on identification and effective repair of OASIS may improve outcomes for women who experience this complication.

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.

How comparable is clinical grading of obstetric anal sphincter injury with that determined by four-dimensional translabial ultrasound?

OBJECTIVES

To evaluate the agreement between grading of obstetric anal sphincter injuries (OASI) on translabial ultrasound (TLUS), using a newly developed algorithm, and grading on postpartum examination. A secondary aim was to assess the correlation between tear severity, as defined on ultrasound, and symptoms of anal incontinence and/or fecal urgency.

METHODS

This was a retrospective study of patients seen at a perineal clinic between 2012 and 2018, after recent primary repair of OASI. All patients underwent a standardized interview including the St Mark's anal incontinence test and four-dimensional TLUS. Post-processing of ultrasound volume data was performed blinded to all other data. Using tomographic ultrasound imaging, a set of eight slices was obtained, and the central six slices were evaluated for sphincter abnormalities. Slices with distortion, thinning or defects were rated as abnormal. The following algorithm was used to grade OASI: a Grade-3a tear was diagnosed if the external anal sphincter (EAS) was abnormal in < 4/6 slices; a Grade-3b tear was diagnosed if the EAS was abnormal in ≥ 4/6 slices; and a Grade-3c/4 tear was diagnosed if both the EAS and internal anal sphincter were abnormal in ≥ 4/6 slices. Clinical grading of OASI was determined according to the Royal College of Obstetricians and Gynaecologists guidelines. Agreement between clinical and TLUS diagnosis of OASI was evaluated using weighted κ.

RESULTS

Of the 260 women seen during the study period, 45 (17%) were excluded owing to missing data or a repeat OASI, leaving 215 complete datasets for analysis. The average follow-up interval was 2.4 months (range, 1-11 months) after OASI and the mean age of the women was 29 years (range, 17-42 years). One hundred and seventy-five (81%) women were vaginally primiparous. OASI was graded clinically as Grade 3a in 87 women, Grade 3b in 80, Grade 3c in 29 and Grade 4 in 19. On imaging, full agreement between clinical and TLUS grading was noted in 107 (50%) women, with a weighted κ of 0.398. In 96 (45%) women, there was disagreement by one category, with a weighted κ of 0.74 and in 12 (6%) there was disagreement by two categories. Twenty-four (11%) women were found to have a normal anal sphincter on imaging. Overall, potential clinical over-diagnosis was noted in 72 (33%) women and potential under-diagnosis in 36 (17%). The seniority of the diagnosing obstetrician did not significantly alter agreement between clinical and sonographic OASI grading (κ 0.44, 0.43, and 0.34, for specialists and senior and junior residents, respectively). The association between symptoms of anal incontinence and/or fecal urgency and TLUS grading did not reach significance (P = 0.052).

CONCLUSIONS

Clinical and TLUS-based grading of OASI showed fair agreement. Clinical over-diagnosis may be increasingly common in our population, although under-diagnosis may still occur in a significant minority. Copyright © 2020 ISUOG. Published by John Wiley & Sons Ltd.