Early secondary repair of obstetric anal sphincter injuries (OASIs): experience and a review of the literature

Automatic anal sphincter integrity detection from ultrasound images via convolutional neural networks

BACKGROUND

The anal sphincter complex comprises the anal sphincter and the U-shaped deep and superficial puborectalis muscle. As an important supporting structure of the posterior pelvic floor, together with its surrounding tissues and muscles, the anal sphincter complex maintains the normal physiological functions of defecation and continence.

OBJECTIVE

The plane required for diagnosing anal sphincter injury and the diagnosis of anal sphincter integrity through pelvic floor ultrasound are highly dependent on sonographers' experience. We developed a deep learning (DL) tool for the automatic diagnosis of anal sphincter integrity via pelvic floor ultrasound.

METHODS

A 2D detection network was trained to detect the bounding box of the anal sphincter. The pelvic floor ultrasound image and its corresponding oval mask were input into a 2D classification network to determine the integrity of the anal sphincter. The average precision (AP) and intersection over union (IoU) were used to evaluate the performance of anal sphincter detection. Receiver operating characteristic (ROC) analysis was used to evaluate the performance of the classification model.

RESULTS

The Pearson correlation coefficients (r values) of the topmost and bottommost layers detected by the CNN and sonographers were 0.932 and 0.978, respectively. The best DL model yielded the highest area under the curve (AUC) of 0.808 (95% CI: 0.698-0.921) in the test cohort. The results from the CNN agreed well with the diagnostic results of experienced sonographers.

CONCLUSIONS

We proposed, for the first time, a CNN to obtain the plane required for diagnosing anal sphincter injury on the basis of pelvic floor ultrasound and for preliminarily diagnosing anal sphincter injury.

A UK wide survey of general surgeons' experience of the primary repair of obstetric anal sphincter injuries

AIM

Obstetric anal sphincter injuries (OASIs) are associated with devastating consequences, mainly faecal incontinence. A timely and correct repair is necessary to reduce the risk of maternal morbidity. The aim was to explore the experience and practice of on-call general surgeons in the acute repair of OASIs.

METHOD

A cross-sectional, observational questionnaire study was performed. Registrars and consultants participating in an emergency general surgical rota in the UK were included. A 33-item questionnaire was disseminated over a 9-month period from April 2023. A descriptive, thematic analysis of the data was undertaken.

RESULTS

In all, 310 responses were analysed. 42.3% of colorectal respondents (of which 29% were pelvic floor specialists), 24.3% of general surgeons, 16.7% of hepato-biliary surgeons and 13.7% of upper gastrointestinal surgeons were contacted to assist with an acute repair. Of those contacted, 52.3% typically assisted with a 3C or 4 tear, 54.2% received no training and 95.5% performed less than three acute repairs in the previous year. 57.6% of all respondents were not confident at all in the repair of these injuries, 55% highlighted a lack of experience and 36% mentioned a curricular gap.

CONCLUSION

Surgeons may be called to assist with an acute OASI repair, particularly in cases of severe anatomical disruption. This occurs infrequently. There is a lack of consensus as to who is responsible for these injuries. Obstetricians have structured training in both the recognition and repair of these injuries. This paper serves to highlight the lack of training for surgeons who report doing this surgery despite lacking the required competences.

Obstetric anal sphincter injury in the second birth after perineal wound complication in the first birth: A nationwide register cohort study

OBJECTIVE

To investigate whether perineal wound complications in the first birth, alone or in conjunction with obstetric anal sphincter injury (OASI), is associated with an increased risk of OASI in the second birth.

DESIGN

Nationwide population-based cohort study.

SETTING

Sweden.

POPULATION

Women (n = 411 317) with first and second singleton vaginal births in Sweden, 2001-2019.

METHODS

Data on diagnostic codes and surgical procedures were retrieved from the Swedish Medical Birth Register and the Swedish Patient Register. A perineal wound complication was defined as wound infection, dehiscence or perineal haematoma within 2 months of childbirth.

MAIN OUTCOME MEASURES

Associations between wound complications in the first birth and OASI in the second birth were investigated with logistic regression and presented as adjusted odds ratios (aORs) with 95% confidence intervals (95% CIs).

RESULTS

In total, 2619 (0.6%) women had a wound complication in the first birth, and 5318 (1.3%) had an OASI in the second birth. Women with a wound complication but no OASI in the first birth had more than doubled odds of OASI in the second birth (aOR 2.73, 95% CI 2.11-3.53). Women with OASI and a wound complication in the first birth had almost tenfold odds (aOR 9.97, 95% CI 6.53-15.24) of recurrent OASI.

CONCLUSIONS

Perineal wound complication in the first birth increases the likelihood of OASI in a subsequent birth.

How to Avoid Becoming a Risk Factor of Fecal Incontinence Due to OASIS-A Narrative Review

Third- and fourth-degree anal sphincter injuries are among the most severe traumas women can experience during childbirth, often leading to lifelong continence issues. Despite extensive research, current repair techniques are often inadequate, failing to provide long-term efficiency. The repair of OASIS tends to worsen with time as fecal or anal incontinence increases. This article presents the risk factors for primary repair failure differently from those previously described in the literature, specifically focusing on avoidable risk factors related to obstetricians and surgeons who perform OASIS repair. After reviewing the literature, the following risk areas were identified and described: recurrent OASIS, pitfalls of the current WHO classification, surgical techniques, place in which the repair should be performed, surgical training, factors related to low volumes of patients with grade III-IV injuries, timing of the repair, and failure of primary repair.

The Reliability of 3-Dimensional Endoanal Ultrasonography Early and Late Postpartum

IMPORTANCE

There is no consensus on how to define obstetric anal sphincter defects detected by 3-dimensional endoanal ultrasonography (3D-EAUS), and the reported rates vary significantly in the postpartum period.

OBJECTIVE

The objective of this study was to establish a diagnostic strategy with a high and clinically relevant interrater reliability both early and late postpartum.

STUDY DESIGN

The study was prospective and observational, and 3D-EAUS was performed 10-14 days and 9-12 months postpartum in an unselected cohort of primiparous women with vacuum-assisted deliveries. Two experienced examiners evaluated the ultrasonographic results, which were divided into the categories intact, inconclusive, small, moderate, and large defects based on Starck scores. Three different diagnostic strategies were validated, and the prevalence- and bias-adjusted kappa (PABAK) values calculated.

RESULTS

Of 334 eligible women, 184 (55.1%) completed both examinations. Disagreements involving small defects were predominant and observed in 34 and 39 cases, respectively, at the 2 time points. The highest overall agreement rates (91.3% and 92.4%, respectively) and PABAK values (0.83 and 0.85, respectively) were reached when the disagreements were minimized by dichotomizing the results into Starck scores >4 (designated a significant defect) versus Starck scores 0-4 (all others).

CONCLUSIONS

The interrater reliability of detecting small anal sphincter defects by 3D-EAUS was low at both time points for the 2 experienced raters. In contrast, the interrater reliability of detecting a significant defect was classified as almost perfect agreement at both time points.

Perineal injuries during vaginal birth in low-resource countries

Birth related perineal trauma (BRPT) and obstetric anal sphincter injuries (OASIS) are leading causes of anal incontinence in women, which negatively impacts on their quality of life, resulting in low self-esteem and abandonment. In low resource countries (LRC), the true incidence is not known and since most births are unattended or occur in community-based health care systems, one can anticipate that it is a significant problem. Dissemination of information to women, education of traditional birth attendants, improvement of resources and transport, and training of health professionals on the detection and appropriate surgical management of these injuries will reduce morbidity and improve outcome. Intrapartum measures such as controlled head descent and perineal support, correct episiotomy techniques and selective use of instruments to assist vaginal births is pivotal in avoiding these injuries. Policy makers should prioritize maternity care in LRC, and research is urgently needed to address all aspects of BRPT.

Repair of episiotomy and obstetrical perineal lacerations (first-fourth)

Perineal injury after vaginal delivery is common, affecting up to 90% of women. Perineal trauma is associated with both short- and long-term morbidity, including persistent pain, dyspareunia, pelvic floor disorders, and depression, and may negatively affect a new mother's ability to care for her newborn. The morbidity experienced after perineal injury is dependent on the type of laceration incurred, the technique and materials used for repair, and the skill and knowledge of the birth attendant. After all vaginal deliveries, a systematic evaluation including visual inspection and vaginal, perineal, and rectal exams is recommended to accurately diagnose perineal lacerations. Optimal management of perineal trauma after vaginal birth includes accurate diagnosis, appropriate technique and materials used for repair, providers experienced in perineal laceration repair, and close follow-up. In this article, we review the prevalence, classification, diagnosis, and evidence supporting different closure methods for first- through fourth-degree perineal lacerations and episiotomies. Recommended surgical techniques and materials for different perineal laceration repairs are provided. Finally, best practices for perioperative and postoperative care after advanced perineal trauma are reviewed.

Structured Workshop for Repair of High-Grade Perineal Lacerations Among Obstetrics and Gynecology Residents, The Need for Repetition and Retraining

Objective

The objective of this study was to evaluate the effectiveness of structured workshops in improving the knowledge and skills of obstetrics and gynecology residents for repairing high-grade perineal lacerations.

Materials and methods

This quasi-experimental multicenter study evaluated the baseline knowledge of obstetrics and gynecology residents using an online patient-management problem (PMP) tool. After the initial evaluation, a workshop was conducted using sponge models to teach the practical technique for repairing high-grade perineal lacerations, including external and internal anal sphincter repair. The residents' knowledge was reassessed by PMP exams at 3 and 6 months after the workshop, and the scores were compared to the baseline statistics.

Result

Eighty residents participated in the study, including 26, 22, and 32 at the first, second, and third-year levels of residency, respectively. The total PMP scores significantly improved after three months of the workshop, with an increasing total score from 15.5 (baseline) to 31.3 (p = 0.027) (range of total score from - 63 to + 52). The senior residents performed better before and after three months of the intervention. However, in the six-month follow-up, the total PMP score of all residents decreased to 12.3 with no significant difference with pre-education scores at all levels. Similar significant results were also reported for each PMP question at all levels of residency.

Conclusion

The study found that obstetrics and gynecology residents had substandard knowledge in repairing perineal lacerations. Although the training workshop significantly increased residents' knowledge, its effectiveness diminished over time, indicating a need for continuous or periodic training.

Supplementary Information

The online version contains supplementary material available at 10.1007/s13224-023-01792-6.

Three-Dimensional Transperineal Ultrasound Guiding Early Secondary Repair of Obstetric Anal Sphincter Injury in an Incontinent Patient without Suture Dehiscence

We present the case of a 36-year-old primigravida who gave birth to a 3200 g baby by vacuum-assisted (Kiwi OmniCup™) operative vaginal delivery with mediolateral episiotomy. A "y"-shaped perineal tear with a grade IIIC obstetric anal sphincter injury (OASI) was diagnosed and repaired. Two days after delivery, in the absence of suture dehiscence, she started experiencing complete anal incontinence. A decision was made in association with a proctologic surgeon for an early secondary repair. Before surgery, a Three-dimensional transperineal ultrasound (TPUS) was performed. The exam revealed a major defect of the external anal sphincter at the 11 o'clock position. This allowed for the reopening of only a circumscribed area of the perineal suture and repair of the sphincters using the end-to-end technique. The symptoms regressed completely, and follow-up TPUS demonstrated the gradual wound healing process. Anal incontinence, secondary to obstetric anal sphincter injury (OASI), has a severe negative impact on women's quality of life. TPUS is an effective method to detect sphincter defects and monitor the healing process. This report investigates the feasibility of identifying the sphincter tear in an incontinent puerperal patient without suture dehiscence in order to target early secondary repair while minimizing its extent. TPUS has proven a safe and effective tool to guide early secondary repair of symptomatic OASI complications while minimizing the invasiveness of the procedure. Multidisciplinary management is crucial to ensure the adequate standard of care.

The Predictive Value of PCT and Other Infection Indicators in Postoperative Infection of Epithelial Ovarian Cancer

Purpose

To study the early predictive value of WBC, CRP and PCT on infectious complications after epithelial ovarian cancer surgery, draw ROC curves, and construct a nomogram prediction model.

Patients and Methods

The clinical data of patients with epithelial ovarian cancer in Shengjing Hospital from August 2019 to August 2022 were included. The levels of WBC, CRP and PCT were statistically analyzed on the first, third and fifth days after surgery, and the ROC was plotted. Multivariate logistic regression analysis determined independent influencing factors, individualized nomogram model for predicting the occurrence of postoperative infectious complications was constructed, and the correction curve was used for verification.

Results

A total of 116 patients were enrolled. The postoperative test levels of WBC, CRP and PCT were compared between two groups, and the differences on POD3 and POD5 were statistically significant. The ROC area on POD5 was 0.739, 0.838 and 0.804, respectively, better than that on POD3. Among them, CRP has the greatest value; The predicted value of the combined test of WBC, CRP and PCT on POD5 was greater than that of a single index on POD5. The nomogram model on POD5 was constructed, and the ROC analysis showed that it had a good degree of differentiation.

Conclusion

WBC, CRP and PCT can effectively predict the occurrence of postoperative infectious complications, among which CRP alone has the greatest diagnostic value on POD5, and the combined test value of the three indicators is higher than that of a single index. The nomogram model constructed by the combined indicators on POD5 can assess the risk individually.

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.

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.