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

Residents' Exposure to Obstetric Anal Sphincter Injury: A 16-Year Temporal Trend

IMPORTANCE

Exposure to the surgical management of obstetric anal sphincter injuries (OASIS) is limited during obstetrics training.

OBJECTIVES

The objective of this study was to quantify residents' exposure to OASI repair during 4-year obstetrics and gynecology (OBGYN) residency and examine temporal trends over a 16-year period.

STUDY DESIGN

This was a retrospective cohort study of residents' exposure to OASIS at a community academic hospital from 2007 to 2022. Individuals with documented OASIS (third- or fourth-degree laceration) by International Classification of Diseases, Ninth and Tenth Revisions, codes during vaginal delivery (VD), spontaneous vaginal delivery (SVD), or operative vaginal delivery (OVD), were included. Delivery rates and OBGYN resident positions were examined. Temporal trends in OASIS were analyzed in 4-year epoch to determine average resident exposure during OBGYN residency.

RESULTS

During the 16-year study period, there were 103,234 deliveries (62% VD, 4% OVD, 34% cesarean delivery). Among VDs, there were 2,344 (3.4%) OASIS with 88.5% classified as third-degree and 11.5% as fourth degree. The OASI rate decreased from 4.2% (2007-2010) to 2.9% (2019-2022), whereas OBGYN residents increased by 49% (67 to 99; P < 0.001). Average resident exposure to OASIS decreased from 11 (2007-2010) to 5 (2019-2022; P = 0.55). Subclassification revealed that residents were exposed to 5 third-degree repairs and less than 1 fourth-degree repair, on average, during 2019-2022.

CONCLUSIONS

During 4 years of training, average resident exposure was to 7 OASIS, 6 third degree, and 1 fourth degree. Limited exposure to OASIS during residency may be detrimental, as surgical treatment is a complicated yet essential obstetric procedure that carries significant risk of patient morbidity and potential long-term sequelae. Therefore, reliance on supplementation with simulation may improve surgeon competence in OASI management.

A Care Bundle Aiming to Reduce the Risk of Obstetric Anal Sphincter Injury: A Survey of Women's Experiences

OBJECTIVE

To study experiences of women who gave birth in maternity units that have implemented a 'care bundle' quality improvement initiative to reduce obstetric anal sphincter injury (OASI) and associated morbidity.

DESIGN

Postnatal electronic questionnaire.

SETTING

Twenty-nine maternity units across England, Scotland and Wales.

POPULATION

Women with live vaginal births.

METHODS

Descriptive statistics for quantitative results. Analysis of free-text responses informed by framework method.

MAIN OUTCOME MEASURES

Experience with components of the care bundle: information provision, manual perineal protection (MPP) and post-birth rectal examination.

RESULTS

In this study, 1208 women completed the survey: 684 (56.6%) said they received antenatal information about perineal health, 377 (31.2%) recalled MPP, and 664 (55.0%) recalled rectal examination. Of the 684 women who said they received antenatal information, 595 (87.0%) agreed that the information was easy to understand, and 423 (61.8%) agreed that it helped them to make their own choices to reduce their OASI risk. One hundred and fifty-four (22.5%) agreed that the information made them fearful about giving birth vaginally. Of the 377 women who recalled MPP, 203 (53.9%) felt it provided them with support, and another 97 (25.7%) did not mind the sensation. Of the 664 women who recalled rectal examination, 281 (42.3%) did not mind the exam, and another 335 (50.5%) felt it was uncomfortable but understood its importance. Free-text responses aligned with quantitative results.

CONCLUSIONS

Many women did not recall MPP or rectal examination. The reported experiences for those who recalled these components do not support concerns that the OASI care bundle has negative effects on women's experiences.

The Association Between Levator Ani Integrity and Postpartum Ano-Rectal Dysfunction: A Systematic Review

INTRODUCTION AND HYPOTHESIS

Pregnancy and delivery are commonly associated with ano-rectal dysfunction. In addition, vaginal delivery may impact both the structure and functionality of the pelvic floor. Herein, we systematically reviewed the literature for the potential association between levator ani muscle (LAM) avulsion and ano-rectal function after childbirth.

METHODS

We systematically searched the PubMed, EMBASE, CINAHL, Web of Science Core Collection, CENTRAL (Cochrane), Clinicaltrials.gov, and ICTRP databases from inception. We selected studies reporting on the anatomy of the LAM and ano-rectal function within 24 months after childbirth, the former determined by imaging and the latter measured through validated questionnaires or ano-rectal manometry. Meta-analyses were used to pool data from studies reporting on the association between LAM avulsion and ano-rectal function, with subgroup analysis according to the presence or absence of anal sphincter trauma. Summary odds ratio (OR) and mean difference (MD) are reported with 95% confidence intervals.

RESULTS

From the 7,621 studies identified, 11 were included, reporting on 2,146 women. Ten studies used transperineal ultrasound (TPUS) and one study used magnetic resonance imaging (MRI) for LAM assessment. Ano-rectal function was assessed through validated questionnaires in all but one study, in which ano-rectal manometry was used. There was no evidence for an association between LAM avulsion and symptoms of incontinence (OR 1.75 [0.74, 4.12]; MD 0.13 [-0.58, 0.85]), including in the subgroup of patients with concomitant anal sphincter injury (OR 1.83 [0.71, 4.71]).

CONCLUSIONS

We did not identify an association between LAM avulsion and ano-rectal dysfunction following vaginal childbirth.

Pregnancy in Patients with Inflammatory Bowel Disease: A Narrative Review

Background

The incidence of inflammatory bowel diseases (IBDs) peaks in the fertile age of both women and men. There is a significant lack of knowledge regarding disease-specific aspects of guiding IBD patients through conception, pregnancy, and delivery in clinical routine.

Summary

Patients with IBD often remain voluntarily childless, primarily due to a lack of knowledge. Fertility is generally unaffected in IBD patients, except in those with high disease activity or who have undergone specific abdominal surgeries that may lead to changes in the abdominal cavity, such as inflammatory or postoperative adhesions. Immunosuppressive and immunomodulatory medications are generally considered safe during pregnancy and should be continued to reduce the likelihood of relapses. If flares occur, close monitoring of the mother and the fetus is mandatory, and therapeutic options (conservative, interventional, surgical) have to be weighed thoroughly. Despite advances in treatment, IBD patients remain at increased risk of preterm labor, small-for-gestational-age newborns and are at risk of C-sections, although the current literature suggests vaginal delivery is possible for most patients. C-sections are recommended in patients with active perianal disease.

Key Messages

Patients with IBD wishing to conceive should receive comprehensive preconception counseling about pregnancy-specific aspects of IBD management from an interdisciplinary team of specialists, including IBD gastroenterologists, obstetricians, and colorectal surgeons.

Episiotomy to prevent obstetric anal sphincter injuries during instrumental delivery in nulliparous women: a national prospective comparative cohort study

BACKGROUND

We are lacking data with a high level of evidence on the use of episiotomy during instrumental delivery to prevent anal sphincter injury, which nonetheless presents the highest risk.

OBJECTIVE

Our main objective was to assess the protective effect of episiotomy against obstetric anal sphincter injury in nulliparous women during instrumental delivery according to type of instrument. We also investigated its impact on immediate maternal and neonatal morbidity.

STUDY DESIGN

We conducted a prospective comparative cohort study for clinical trial emulation by means of propensity score weighting. The study was especially designed for consideration of possible confounders. This was a nationwide observational multicenter study including 111 French public and private maternity units between April 2021 and March 2022. We included nulliparous women, with singleton cephalic fetus, at more than 34 weeks of gestation. We considered vacuum, forceps, and spatula deliveries. We proceeded to a comparative analysis between women with and without episiotomy. The main outcome was obstetric anal sphincter injury occurrence. We used composite criteria for both maternal and neonatal immediate morbidity.

RESULTS

The analyses pertained to 11,013 women. Overall prevalence of episiotomy was 23%: 17% for vacuum (N=7007), 37% for forceps (N=2378), and 29% in case of spatula-assisted (N=1628) delivery. Episiotomy was not associated with significantly decreased obstetric anal sphincter injury occurrence in vacuum delivery (from 5.2% without episiotomy to 3.8%, odds ratio=0.73 [0.48-1.03]) or forceps delivery (from 10.9% without episiotomy to 8.8%, odds ratio=0.81 [0.56-1.14]). In contrast, we observed significantly decreased obstetric anal sphincter injury occurrence (from 9.4% without episiotomy to 5.6%) in spatula delivery (odds ratio=0.60 [0.37-0.87]). Episiotomy was associated with increased maternal morbidity using forceps (from 13.6%-18.3%, odds ratio=1.35 [1.01-1.73]) and spatulas (from 9.0%-13.4%, odds ratio=1.51 [1.11-2.00]). We also observed increased neonatal morbidity in vacuum delivery associated with episiotomy (from 9.1%-13.6%, odds ratio=1.49 [1.21-1.79]), but a decrease in case of forceps delivery with episiotomy (from 12.6%-9.2%, odds ratio=0.74 [0.55-0.95]).

CONCLUSION

Episiotomy was not associated with a decreased risk of obstetric anal sphincter injury in vacuum or forceps delivery, and a marginal reduction was achieved using spatulas. Our results do not favor extensive episiotomy during instrumental delivery.

TRIAL REGISTRATION

ClinicalTrial NCT 04446780.

Controversies in fecal incontinence

Fecal incontinence is a common condition that can significantly impact patients' quality of life. Obstetric anal sphincter injury and anorectal surgeries are common etiologies. Endoanal ultrasound and anorectal manometry are important diagnostic tools for evaluating patients. There are various treatment options, including diet, lifestyle modifications, drugs, biofeedback therapy, tibial and sacral nerve neuromodulation therapy, and surgery. In this editorial, we will discuss current controversies and novel approaches to fecal incontinence. Screening for asymptomatic anal sphincter defects after obstetric anal sphincter injury and in patients with inflammatory bowel disease is not generally recommended, but may be helpful in selected patients. The Garg incontinence score is a new score that includes the assessment of solid, liquid, flatus, mucous, stress and urge fecal incontinence. Novel tests such as translumbosacral anorectal magnetic stimulation and novel therapies such as translumbosacral neuromodulation therapy are promising diagnostic and treatment options, for both fecal incontinence and neuropathy. Home biofeedback therapy can overcome some limitations of the office-based therapy. Skeletal muscle-derived cell implantation of the external anal sphincter has been further studied as a possible treatment option. Sacral neuromodulation may be useful in scleroderma, congenital fecal incontinence and inflammatory bowel disease but merits further study.

The Impact of Pelvic Floor Muscle Strengthening on the Functional State of Women Who Have Experienced OASIS After Childbirth

Background and Objectives: The primary objective of this study was to assess the impact of pelvic floor muscle (PFM) strengthening on the pelvic floor function in women who have experienced OASIS two years after delivery, and the secondary objective was to educate women about PFM strengthening and instruct them on the correct way to exercise. Methods and Materials: A prospective case-control study was conducted. The participants were divided into two groups: the case group (women who experienced OASIS) and the control group (women who did not experience perineal tears but had similar obstetric-related data to the case). Women were invited for a gynecological exam, PFM assessment, and consultation on PFM training. Women in the case group had three consultations, and women in the control group had two. Women were presented with four sets of questions about pre-pregnancy condition and questions related to UI and FI after delivery. Results were considered significant when p < 0.05. Results: OASIS were detected in 13 (0.4%) women in 2021. Risk factors for OASIS were found to be fetal macrosomia (p = 0.012), fetal occiput posterior position (p = 0.001), and epidural analgesia (p = 0.003). After one year of performing PFM strengthening exercises, some women in the study group exhibited stronger PFM contractions (p = 0.076), while others held the contracted PFM for a longer time (p = 0.133). UI affected women in the control group more often (p = 0.019). Two years after delivery, gas incontinence was mentioned significantly more frequently in the case group (p = 0.019). One year after initial consultation, gas incontinence was also more significantly common in the case group (p = 0.037). Conclusions: This study found that PFM strengthening exercises significantly improved pelvic floor function in women who experienced OASIS two years after delivery. Participants exhibited stronger PFM contractions and an increased ability to maintain these contractions. Women reported a better understanding of PFM exercises and proper techniques.

Guideline No. 457: Obstetrical Anal Sphincter Injuries (OASIS) Part I: Prevention, Recognition, and Immediate Management

OBJECTIVE

The purpose of this guideline is to promote recognition and preventive strategies for obstetrical anal sphincter injuries. Furthermore, it provides guidance on primary repair and immediate postpartum management for obstetrical anal sphincter tears in order to minimize further negative sequelae.

TARGET POPULATION

All patients having a vaginal delivery and those who have sustained an obstetrical anal sphincter injury.

OUTCOMES

Certain preventive strategies have been associated with lower rates of obstetrical anal sphincter injuries (e.g., fetal head flexion and control, appropriate use of mediolateral episiotomy). Management strategies, including appropriate diagnosis and repair of obstetrical anal sphincter injuries, antibiotic prophylaxis, and bowel and bladder function management can decrease associated short- and long-term complications.

BENEFITS, HARMS, AND COSTS

Implementation of the recommendations in this guideline may increase detection, prevention, and appropriate management of obstetrical anal injuries, thus limiting the future burden associated with these injuries. Implementation of the recommended classification of obstetrical anal sphincter injuries will improve national and international research efforts.

EVIDENCE

Published literature was retrieved through searches of PubMed, Ovid, Medline, Embase, Scopus, and the Cochrane Library from September 1, 2014, through November 30, 2023, using appropriate MeSH terms (delivery, obstetrics, obstetric surgical procedures, obstetric labor complications, anal canal, episiotomy) and keywords (OASIS, obstetrical anal sphincter injury, anal injury, anal sphincter, vaginal delivery, suture, fecal incontinence, anal incontinence, overlap repair, end-to-end repair, bladder protocol, analgesia). Results were restricted to systematic reviews, meta-analyses, randomized controlled trials/controlled clinical trials, observational studies, and clinical practice guidelines. Results were limited to English- or French-language materials. Evidence was supplemented with references from the 2015 Society of Obstetricians and Gynaecologists of Canada guideline no. 330.

VALIDATION METHODS

The authors rated the quality of evidence and strength of recommendations using the Grading of Recommendations Assessment, Development and Evaluation (GRADE) approach. See online Appendix A (Tables A1 for definitions and A2 for interpretations of strong and conditional recommendations).

INTENDED AUDIENCE

Obstetrical care providers.

TWEETABLE ABSTRACT

Updated Canadian guideline on recognition, prevention and management of obstetrical anal sphincter injuries (OASIS).

SUMMARY STATEMENTS

RECOMMENDATIONS.

Hyaluronidase for reducing perineal trauma

BACKGROUND

Perineal trauma after vaginal birth is common and can be associated with short- and long-term health problems. Perineal hyaluronidase (HAase) injection has been widely used to reduce perineal trauma, perineal pain and the need for episiotomy since the 1950s. The administration of HAase is considered to be a simple, low risk, low cost and effective way to decrease perineal trauma without causing adverse effects.

OBJECTIVES

To assess the effectiveness and safety of perineal HAase injection for reducing perineal trauma, episiotomy and perineal pain during vaginal delivery.

SEARCH METHODS

To identify studies for inclusion in this review, we searched the Cochrane Central Register of Controlled Trials, Ovid MEDLINE, Embase, CINAHL (EBSCOhost), ClinicalTrials.gov and WHO International Clinical Trials Registry Platform (ICTRP) in November 2023.

SELECTION CRITERIA

Randomised and quasi-randomised controlled trials comparing women giving birth to their first baby receiving perineal HAase injection compared to placebo injection or no intervention during vaginal delivery of a single foetus with vertex foetal presentation (foetus with head engaging the maternal pelvis).

DATA COLLECTION AND ANALYSIS

We used standard methodological procedures expected by Cochrane. Two review authors independently assessed trials for inclusion, extracted and checked data, and evaluated the risk of bias in the studies. Our primary outcomes were perineal trauma (tears or episiotomy, or both), episiotomy and perineal pain. Our secondary outcomes were first and second degree perineal lacerations, third and fourth degree perineal lacerations, perineal oedema 1 hour after vaginal delivery, perineal oedema 24 hours after vaginal delivery and neonatal Apgar scores of less than 7 at five minutes after birth (Apgar score is a measure of the health status of a newborn). We assessed the certainty of the evidence using the GRADE approach.

MAIN RESULTS

We included five randomised controlled trials involving a total of 747 women (data were available for 743 women). The dosage of HAase used in the perineal injection varied from 750 turbidity-reducing units to 5000 international units. The certainty of the evidence was largely low (ranging from very low to moderate). Perineal HAase injection versus placebo injection Data from three trials involving 426 women provided low-certainty evidence that there may be no difference between the HAase and placebo groups in the incidence of perineal trauma (tears or episiotomy, or both) (RR 0.94, 95% CI 0.87 to 1.03; 426 participants, 3 studies), episiotomy (RR 0.91, 95% CI 0.71 to 1.15; 427 participants, 3 studies), first and second degree perineal lacerations (RR 1.02, 95% CI 0.87 to 1.18; 341 participants, 3 studies), third and fourth degree perineal lacerations (RR 0.46, 95% CI 0.11 to 2.05; 426 participants, 3 studies), and perineal oedema one hour after vaginal delivery (RR 0.99, 95% CI 0.78 to 1.25; 303 participants, 2 studies). Moreover, perineal HAase injection during the second stage of labour likely resulted in a reduction in incidence of perineal oedema 24 hours after vaginal delivery compared with placebo injection (RR 0.42, 95% CI 0.26 to 0.70; 303 participants, 2 studies; moderate-certainty evidence). There may be no difference between groups in Apgar scores less than 7 at five minutes (RR 5.00, 95% CI 0.24 to 105.95; 148 participants, 1 study; low-certainty evidence). Perineal HAase injection versus no intervention Data from three trials involving 373 women suggested that perineal HAase injection during the second stage of labour may result in a lower incidence of perineal trauma (tears or episiotomy, or both) (RR 0.61, 95% CI 0.42 to 0.88; 373 participants, 3 studies; low-certainty evidence) compared with no intervention. The evidence is very uncertain for episiotomy (RR 0.79, 95% CI 0.44 to 1.42; 373 participants, 3 studies), first and second degree perineal lacerations (RR 0.59, 95% CI 0.30 to 1.18; 373 participants, 3 studies) and perineal oedema one hour after vaginal delivery (RR 0.32, 95% CI 0.01 to 7.71; 139 participants, 1 study), all very low certainty evidence. No third and fourth degree perineal lacerations, perineal oedema 24 hours after vaginal delivery or Apgar scores less than 7 at five minutes were reported in these three trials. No side effects were reported in the included trials.

AUTHORS' CONCLUSIONS

Perineal HAase injection during the second stage of labour may result in a lower incidence of perineal trauma (tears or episiotomy, or both) compared with no intervention, but not compared with placebo injection, in women having a vaginal delivery. Meanwhile, perineal HAase injection likely reduces the incidence of perineal oedema 24 hours after vaginal delivery compared with placebo injection. The potential use of perineal HAase injection as a method to reduce perineal trauma and perineal oedema remains to be determined as the number of high-quality trials and outcomes reported was too limited to draw conclusions on its effectiveness and safety. Further rigorous randomised controlled trials are required to evaluate the role of perineal HAase injection in vaginal deliveries, including evaluating whether there is any differential effect based on the dose, frequency and positioning of HAase injection.

Is vaginal birth after cesarean section a risk factor for obstetric anal sphincter injury?

OBJECTIVE

To investigate whether women undergoing their first vaginal delivery after a previous cesarean section (secundiparous) are at increased risk for obstetric anal sphincter injury (OASI) compared with primiparous women.

METHODS

A retrospective cohort study of 85 428 women who delivered vaginally over a 10-year period in a single tertiary medical center. Incidence of OASI, risk factors, and clinical characteristics were compared between primiparous women who delivered vaginally and secundiparous women who underwent their first vaginal birth after cesarean section (VBAC). A multivariable logistic regression analysis was used to study the association between VBAC and OASI.

RESULTS

Overall, 36 250 primiparous and 1602 secundiparous women were enrolled, 309 of whom had OASI. The rates of OASI were similar among secundiparous women who had VBAC and primiparous women who underwent vaginal delivery (15 [0.94%] vs 294 [0.81%], P = 0.58). The proportions of third- and fourth-degree tears were also similar among secundiparous and primiparous women who experienced OASI (87% vs 91.5%, and 13% vs 8.5%, respectively, P = 0.68). Furthermore, the rates of OASI were similar in both study groups, although secundiparous women who underwent VBAC had higher rates of birth weights exceeding 3500 g (414 [25.8%] vs 8284 [22.8%], P = 0.016), and higher rates of vacuum-assisted deliveries (338 [21%] vs 6224 [17.2%], P < 0.001). A multivariate logistic regression analysis failed to establish a statistically significant association between VBAC and OASI (odds ratio 0.672, 95% confidence interval 0.281-1.61, P = 0.37).

CONCLUSIONS

No increased risk for OASI was found in secundiparous women who underwent VBAC compared with primiparous women at their first vaginal birth.

Occurrence and risk factors for second-degree perineal tears: A prospective cohort study using a detailed classification system

BACKGROUND

The amount of tissue trauma within second-degree perineal tears varies widely. Therefore, subcategorization of second-degree tears and a better understanding of their occurrence and risk factors are needed. The aim of this study was to assess the occurrence of perineal tears when second-degree tears were subcategorized. Furthermore, we aimed to assess the association between variables related to perineal anatomy and other potential risk factors, with second-degree tear subcategories.

METHODS

This prospective cohort study included 880 primiparous and multiparous women giving birth to one child vaginally. Perineal tears were categorized using the classification system recommended by the Royal College of Obstetricians and Gynaecologists. In addition, second-degree tears were subcategorized as 2A, 2B, or 2C according to the percentage of damage to the perineal body. Selected variables related to perineal anatomy were as follows: length of genital hiatus; perineal body length; and previous perineal trauma. Risk factors for second-degree tear subcategories were analyzed using a multinominal regression model.

RESULTS

Perineal tears occurred as follows: first-degree: 35.6% (n = 313), 2A: 16.3% (n = 143), 2B: 9.1% (n = 80), 2C: 6.6% (n = 58), and third- or fourth-degree: 1.6% (n = 14). In total, 169/880 participants underwent an episiotomy. When episiotomies were excluded, the risk for 2B, or 2C tears increased with smaller genital hiatus, larger perineal body, previous perineal trauma, primiparity, higher gestational age, instrumental vaginal delivery and fetal presentation other than occiput anterior.

CONCLUSION

The occurrence of second-degree tear subcategories was 16.3% for 2A tears, 9.1% for 2B tears, and 6.6% for 2C tears. Factors related to perineal anatomy increased the odds for experiencing a second-degree tear in a more severe subcategory.

Caesarean section and anal incontinence in women after obstetric anal sphincter injury: A systematic review and meta-analysis

BACKGROUND

Approximately 50% women who give birth after obstetric anal sphincter injury (OASI) develop anal incontinence (AI) over their lifetime.

OBJECTIVE

To evaluate current evidence for a protective benefit of planned caesarean section (CS) to prevent AI after OASI.

SEARCH STRATEGY

MEDLINE/PubMed, Embase 1974-2024, CINAHL and Cochrane to 7 February 2024 (PROSPERO CRD42022372442).

SELECTION CRITERIA

All studies reporting outcomes after OASI and a subsequent birth, by any mode.

DATA COLLECTION AND ANALYSIS

Eighty-six of 2646 screened studies met inclusion criteria, with nine studies suitable to meta-analyse the primary outcome of 'adjusted AI' after OASI and subsequent birth. Subgroups: short-term AI, long-term AI, AI in asymptomatic women.

SECONDARY OUTCOMES

total AI, quality of life, satisfaction/regret, solid/liquid/flatal incontinence, faecal urgency, AI in women with and without subsequent birth, change in AI pre- to post- subsequent birth.

MAIN RESULTS

There was no evidence of a difference in adjusted AI after subsequent vaginal birth compared with CS after OASI across all time periods (OR = 0.92, 95% CI 0.72-1.20; 9 studies, 2104 participants, I2 = 0% p = 0.58), for subgroup analyses or secondary outcomes. There was no evidence of a difference in AI in women with or without subsequent birth (OR = 1.00 95% CI 0.65-1.54; 10 studies, 970 participants, I2 = 35% p = 0.99), or pre- to post- subsequent birth (OR = 0.79 95% CI 0.51-1.25; 13 studies, 5496 participants, I2 = 73% p = 0.31).

CONCLUSIONS

Due to low evidence quality, we are unable to determine whether planned caesarean is protective against AI after OASI. Higher quality evidence is required to guide personalised decision-making for asymptomatic women and to determine the effect of subsequent birth mode on long-term AI outcomes.

A sensorised surgical glove to improve training and detection of obstetric anal sphincter injury: A preclinical study on a pig model

OBJECTIVE

To create a sensorised surgical glove that can accurately identify obstetric anal sphincter injury to facilitate timely repair, reduce complications and aid training.

DESIGN

Proof-of-concept.

SETTING

Laboratory.

SAMPLE

Pig models.

METHODS

Flexible triboelectric pressure/force sensors were mounted onto the fingertips of a routine surgical glove. The sensors produce a current when rubbed on materials of different characteristics which can be analysed. A per rectum examination was performed on the intact sphincter of pig cadavers, analogous to routine examination for obstetric anal sphincter injuries postpartum. An anal sphincter defect was created by cutting through the vaginal mucosa and into the external anal sphincter using a scalpel. The sphincter was then re-examined. Data and signals were interpreted.

MAIN OUTCOME MEASURES

Sensitivity and specificity of the glove in detecting anal sphincter injury.

RESULTS

In all, 200 examinations were performed. The sensors detected anal sphincter injuries in a pig model with sensitivities between 98% and 100% and a specificity of 100%. The current produced when examining an intact sphincter and sphincter with a defect was significantly different (p < 0.001).

CONCLUSION

In this preliminary study, the sensorised glove accurately detected anal sphincter injury in a pig model. Future plans include its clinical translation, starting with an in-human study on postpartum women, to determine whether it can accurately detect different types of obstetric anal sphincter injury in vivo.

Complications 8 weeks after an obstetric second-degree perineal laceration in relation to body mass index

INTRODUCTION AND HYPOTHESIS

How body mass index (BMI) affects pelvic floor function after a second-degree perineal laceration is unknown. The hypothesis of this study is that pelvic floor dysfunction and complications after an obstetric second-degree perineal laceration are more common in women with a higher BMI 8 weeks postpartum.

METHODS

This register-based cohort study includes 10,876 primiparous women with an obstetric second-degree perineal laceration between 2014 and 2021. Data were retrieved from the Swedish Perineal Laceration Registry. Outcomes in relation to maternal BMI were urinary incontinence (UI), anal incontinence (AI) and common complications attributable to the laceration. Uni- and multivariate logistic regressions were used for comparison between normal weight (BMI < 24.9, reference), overweight (25.0-29.9) and obese (≥ 30) women.

RESULTS

Multivariate analyses showed an increased risk for UI in both overweight and obese women compared to normal-weight women 8 weeks after a second-degree perineal laceration with an adjusted odds ratio (aOR) of 1.21 (CI 1.02-1.44) and 1.27 (CI 1.13-1.58) respectively. Overweight and obese women had a decreased risk for AI (aOR 0.81, CI 0.68-0.96; aOR 0.72, CI 0.57-0.90 respectively) compared with normal-weight women. No significant differences were found in the univariate analyses over BMI strata concerning complications after perineal laceration.

CONCLUSIONS

Primiparous overweight and obese women report less AI and more UI than normal-weight women 8 weeks after a second-degree perineal laceration. No differences were found regarding complications. These findings are new and merit further study to find potential preventive factors and interventions after a second-degree perineal laceration.

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.