Levator Ani Muscle Avulsion Research Articles

Long-term follow-up after laparoscopic reparation of pelvic organ prolapses in a large teaching gynecological center

ObjectiveTo provide a description of laparoscopic approach to correct pelvic organ prolapses and evaluate the risk factors associated with the prolapse recurrence Study designWe retrospectively analyzed 418 patients with symptomatic pelvic organ prolapse who underwent a laparoscopic reparation at our university center from 2010 to 2020. Prolapses were assessed by Baden-Walker system (stage I–IV). The association between the potential prognostic factors and the recurrence was analyzed using Cox regression. ResultsWe included 418 patients. Most patients (97.6 %) had at least one vaginal delivery and 92 (22 %) had a previous prolapse surgery. In 29.74 % of cases levator ani muscle avulsion was observed. We performed a cervicosacropexy in 336 (80.38 %) cases, a sacrohysteropexy in 13 (3.11 %), and a sacrocolpopexy in 69 (16.5 %). Also, concomitantly, 66 (15.79 %) patients with stress and occult urinary incontinence underwent TOT surgery. Surgical complications were low (9.51 %) and the majority were minor. Median follow-up was 37 months (IQR 10.5, 61.4 months), and the global recurrence rate was 9.57 %. Only 4.06 % of cases required reintervention. In Cox regression analysis only levator ani muscle avulsion remained as a recurrence-associated factor. ConclusionOur series is one of the largest and with the longest follow-up. Recurrence rate was low, and comparable to other large series. The only independent factor related to recurrence was the levator ani muscle avulsion.

Association of pre-pregnancy body mass index and gestational weight gain on postpartum pelvic floor muscle morphology and function in Chinese primiparous women: A retrospective cohort study.

Our study aimed to investigate the association between maternal pre-pregnancy body mass index (BMI), gestational weight gain (GWG), and impaired pelvic floor muscle (PFM) morphology and function during the early postpartum period. This retrospective cohort study was conducted at Shanghai First Maternity and Infant Hospital from December 2020 to December 2022. A total of 1118 primiparous women with singleton pregnancies who underwent vaginal deliveries and participated in postpartum PFM assessments were included. Maternal pre-pregnancy BMI and GWG were considered as exposures. PFM morphology and function impairment were the primary outcomes. PFM morphology impairment, defined as levator ani muscle avulsion, was assessed using transperineal ultrasound. PFM function impairment, manifested as diminished PFM fiber strength, was assessed through vaginal manometry. Multivariable logistic regression analysis was employed to calculate adjusted odds ratios (aOR) with 95% confidence intervals (CI). Restricted cubic spline models were used to validate and visualize the relationship. Women with lower pre-pregnancy BMI were at an increased risk of levator ani muscle avulsion (aOR = 1.73, 95% CI: 1.10-2.70, P = 0.017), particularly when combined with excessive GWG during pregnancy (aOR = 3.20, 95% CI: 1.15-8.97, P = 0.027). Lower pre-pregnancy BMI was also identified as an independent predictor of PFM weakness (aOR = 1.53, 95% CI: 1.08-2.16, P = 0.017 for type I fiber injuries). Notably, regardless of the avulsion status, both underweight and overweight/obese women faced an elevated risk of reduced PFM strength (aOR = 1.74, 95% CI: 1.17-2.59, P = 0.006 for underweight women with type I fiber injuries; aOR = 1.67, 95% CI: 1.06-2.64, P = 0.027; and aOR = 1.73, 95% CI: 1.09-2.76, P = 0.021 for overweight/obese women with type I and type II fibers injuries, respectively). Both lower and higher pre-pregnancy BMI, as well as excessive GWG, were strongly associated with PFM impairments. These findings highlighted the critical importance of comprehensive weight management throughout pregnancy to effectively promote women's pelvic health.

Levator Ani Muscle Avulsion After Vaginal Delivery Comparing Routine Versus Restrictive Episiotomy: A Pilot Study.

The objective was to compare the rate of levator ani muscle avulsion following vaginal birth after routine and restrictive episiotomy. This study consists of two cohorts of pregnant women prospectively enrolled between September 2015 and December 2017 at a university hospital. The pregnant women were subject to a randomized controlled trial, in which participants received a restrictive episiotomy protocol versus a routine episiotomy protocol for vaginal delivery. Levator ani avulsion was evaluated by four-dimensional ultrasound screening. Sixty-one post-partum primipara women were enrolled in our study. Thirty-two women (52.5%) had undergone routine episiotomy whereas 29 women (47.5%) had gone through restrictive episiotomy. Right mediolateral episiotomies were performed in all cases. The rate of anal sphincter tear was 12.5% in the routine episiotomy group versus 13.8% in the restrictive episiotomy group (p = 1.00). Levator ani avulsion was detected in 9.4% of the routine episiotomy group (only on the right side) and in 10.3% of the restrictive episiotomy group (p = 1.00). No bilateral levator avulsion was detected in either of the groups. There were no statistical differences in the distances of the bladder neck descent, cystocele descent, uterine descent, rectocele descent, and the ballooning of the genital hiatus area between the groups. In our pilot study, there was no reduction of the rate of levator ani avulsion in women with restrictive episiotomy compared with routine episiotomy. There were no differences in pelvic floor ultrasound parameters between the two groups.

Effect of an Intrapartum Pelvic Dilator Device on Levator Ani Muscle Avulsion During Primiparous Vaginal Delivery: A Pilot Randomized Controlled Trial

Introduction and HypothesisThe objective was to evaluate the safety and effectiveness of an intrapartum electromechanical pelvic floor dilator designed to reduce the risk of levator ani muscle (LAM) avulsion during vaginal delivery.MethodsA multicenter, randomized controlled trial enrolled nulliparous participants planning vaginal delivery. During the first stage of labor, participants were randomized to receive the intravaginal device or standard-of-care labor management. The primary effectiveness endpoint was the presence of full LAM avulsion on transperineal pelvic-floor ultrasound at 3 months. Three urogynecologists performed blinded interpretation of ultrasound images. The primary safety endpoint was adverse events (AEs) through 3 months.ResultsA total of 214 women were randomized to Device (n = 113) or Control (n = 101) arms. Of 113 Device assignees, 82 had a device placed, of whom 68 delivered vaginally. Of 101 Control participants, 85 delivered vaginally. At 3 months, 110 participants, 46 Device subjects who received full device treatment, and 64 Controls underwent ultrasound for the per-protocol analysis. No full LAM avulsions (0.0%) occurred in the Device group versus 7 out of 64 (10.9%) in the Control group (p = 0.040; two-tailed Fisher’s test). A single maternal serious AE (laceration) was device related; no neonate serious AEs were device related.ConclusionsThe pelvic floor dilator device significantly reduced the incidence of complete LAM avulsion in nulliparous individuals undergoing first vaginal childbirth. The dilator demonstrated an acceptable safety profile and was well received by recipients. Use of the intrapartum electromechanical pelvic floor dilator in laboring nulliparous individuals may reduce the rate of LAM avulsion, an injury associated with serious sequelae including pelvic organ prolapse.

Levator ani muscle avulsion and subsequent vaginal delivery: 8-year longitudinal follow-up.

To assess the evolution of levator ani muscle (LAM) avulsion from 1 year to 8 years after first delivery in women with and those without subsequent vaginal delivery. In addition, to assess whether women with full or partial avulsion 8 years after first delivery have larger LAM hiatal area and more symptoms of pelvic organ prolapse compared to women with normal LAM insertion. In this single-center longitudinal study, 195 women who were primiparous at the start of the study were included and underwent transperineal ultrasound examination 1 year and 8 years after first delivery. Muscle insertion was assessed by tomographic ultrasound imaging in the axial plane. Full LAM avulsion was defined as abnormal muscle insertion in all three central slices. Partial LAM avulsion was defined as abnormal muscle insertion in one or two central slices. Eight years after the first delivery, LAM hiatal area was assessed at rest, during maximum pelvic floor muscle contraction and on maximum Valsalva maneuver. To assess symptoms of pelvic organ prolapse, the vaginal symptoms module of the International Consultation on Incontinence Questionnaire was used. At 1-year follow-up, 25 (12.8%) women showed signs of LAM avulsion, of whom 20 fulfilled the sonographic criteria of full avulsion and five of partial avulsion. Eight years after the first delivery, 35 (17.9%) women were diagnosed with avulsion, of whom 25 were diagnosed with full avulsion and 10 with partial avulsion. No woman with partial or full avulsion at 1 year had improved avulsion status at the 8-year follow-up. Of the 150 women who had subsequent vaginal delivery, 21 (14.0%) women were diagnosed with partial or full LAM avulsion 1 year after first delivery, and 31 (20.7%) women were diagnosed with partial or full avulsion 8 years after first delivery. Of the 45 women without subsequent vaginal delivery, one woman with partial avulsion 1 year after first delivery was diagnosed with full avulsion at the 8-year follow-up. All women with full avulsion at 1-year follow-up were diagnosed with full avulsion at the 8-year follow-up regardless of whether they had subsequent vaginal delivery. At 8-year follow-up, women with full avulsion had statistically significantly larger LAM hiatal area compared to women with normal muscle insertion. Mean ± SD vaginal symptom scores ranged between 5.5 ± 5.7 and 6.0 ± 4.0 and vaginal symptom quality of life scores ranged between 0.9 ± 1.4 and 1.5 ± 2.2 and did not differ significantly between women with normal muscle insertion and women with partial or full avulsion at 8-year follow-up. More LAM avulsions were present 8 years compared with 1 year after first delivery in women with subsequent vaginal delivery. Except for one primipara, all women without subsequent vaginal delivery had unchanged LAM avulsion status between 1 year and 8 years after their first delivery. Larger LAM hiatal area was found in women with full avulsion compared to those with normal muscle insertion at 8-year follow-up. Vaginal symptoms scores were low and did not differ between women with normal muscle insertion and those with partial or full avulsion at 8-year follow-up. © 2024 The Authors. Ultrasound in Obstetrics & Gynecology published by John Wiley & Sons Ltd on behalf of International Society of Ultrasound in Obstetrics and Gynecology.

Obstetric risk factors for levator ani muscle avulsion: A systematic review and meta-analysis

ObjectivesWomen have a 11% lifetime risk of undergoing surgery for vaginal prolapse. Levator ani muscle (LAM) avulsion is one etiological factor associated with primary and recurrent pelvic organ prolapse. Pelvic organ prolapse has been shown to greatly affect the quality of life and well-being of women. Conduct a meta-analysis identifying risk factors associated with LAM avulsion recognised on transperineal ultrasound (TPUS) or magnetic resonance imaging (MRI) in primiparous women after vaginal birth. Study designOVID Medline, Embase and the Cochrane Library from inception to January 2021 were searched. Review Manager 5.3 (The Cochrane Collaboration) was used to analyse data. Odds ratios (OR) with 95% confidence intervals (95% CIs) were calculated. The heterogeneity among studies was calculated using the I2statistic. ResultsTwenty-five studies were eligible for inclusion (n = 9333 women). Major LAM avulsion was diagnosed in an average of 22 % (range 12.7–39.5 %) of cases. Twenty-two studies used TPUS and three used MRI to diagnose avulsion. Modifiable and non-modifiable risk factors were identified. Significant predictors identified were forceps (OR 6.25 [4.33 – 9.0]), obstetric anal sphincter injuries (OR 3.93 [2.85–5.42]), vacuum (OR 2.41 [1.40–4.16]), and maternal age (OR 1.06 [1.02–1.10]). ConclusionsThis is the first meta-analysis of both modifiable and non-modifiable risk factors associated with LAM avulsion. This information could be used to develop a clinically applicable risk prediction model to target postnatal women at risk of LAM avulsion with a view to prevent the onset of pelvic floor organ prolapse.

Comparison of Cross-Sectional Area of Pubovisceral Muscle in Nulliparous and Primiparous Women

Introduction and HypothesisThe main risk factor for pelvic floor disorders is vaginal delivery, which may cause levator ani muscle (LAM) injury and denervation. LAM includes pubovisceral muscle (PVM, pubococcygeus), puborectalis muscle (PRM), and iliococcygeus muscle. We hypothesize that primiparous women with low pelvic floor muscle contraction have a reduced PVM cross-sectional area (CSA) compared to nulliparous women.Methods (Sample Size and Statistical Approaches)This single-centre prospective observational study compared healthy nulliparous (n = 40) to primiparous (n = 40) women after vaginal delivery without LAM avulsion and Oxford score ≤ 3. Demographics, questionnaires (ICIQ-UI-SF, OAB-Q-SF, PISQ-12), POP-Q, Oxford score, ultrasound measurements (minimal anteroposterior and lateral diameters, hiatal area, PRM thickness, levator-urethra gap) and magnetic resonance imaging (MRI)—PVM CSA were evaluated. Normality was tested, and an appropriate test was used to compare the groups. Power calculation suggested 40 participants per group.ResultsThe primiparous group was older, had a higher BMI, and their hiatal area on ultrasound at contraction was larger compared to the nulliparous group. The CSA of the left-sided PVM (1.15 ± 0.50 cm2) was larger compared to the right side (1.03 ± 0.50 cm2), p = 0.02 in nulliparous women. The PVM CSA of primiparous women with low Oxford score was reduced compared to nulliparous (0.87 ± 0.30 versus 1.09 ± 0.50 cm2, p = 0.006). The intra-rater reliability for PVM CSA had an ICC of 0.90 and inter-rater ICC of 0.77.ConclusionsPrimiparous women after vaginal delivery with low pelvic floor contraction force had reduced PVM CSA on MRI images compared to nulliparous women.

Levator Ani Avulsion in Ultrasound Increases Recurrence in Sacrospinous Fixation.

Pelvic floor translabial ultrasound (TLUS) can identify levator ani muscle (LAM) avulsion and ballooning, which some studies have shown to be possible risk factors for prolapse recurrence. Our group uses TLUS to counsel patients preoperatively. If any of these risk factors exist, we offer sacrocolpopexy over vaginal repair. However, some patients, even though they have these possible risk factors, prefer to undergo vaginal surgery. The objective of this study was to determine if TLUS LAM avulsion and/or ballooning are risk factors for composite outcome recurrence in patients undergoing sacrospinous ligament fixation for pelvic organ prolapse. This was a retrospective observational study. All patients with vaginal apical repair with sacrospinous ligament fixation with preoperative TLUS were included. Demographics, clinical characteristics, and follow-up were analyzed. Multivariable logistic regression analysis was performed for composite outcome that included TLUS risk factors, age, Pelvic Organ Prolapse Quantification System measurements and stage, and variables with P < 0.1 in the univariate analysis. Eighty-two patients were included. All patients had symptomatic vaginal bulge; 65.4% had stage III prolapse. Concomitant hysterectomy was performed in 54.3%. Median follow-up was 20 months (interquartile range, 8-35 months); 19.8% had LAM avulsion, and 43.2% had ballooning. Anatomic recurrence rate was 23.5%, symptomatic was 22.2%, and reoperation was 1.2%. The composite recurrence rate was 29.6%. In the multivariable logistic regression analysis, unilateral/bilateral avulsion in TLUS was found to be a significant risk factor for composite outcome with an odds ratio of 4.33 (confidence interval, 1.219-15.398; P = 0.023). Composite outcome of recurrence in our study was 29.6%. Avulsion on TLUS increased the risk of recurrence of pelvic organ prolapse by fourfold.

A biomechanical perspective on perineal injuries during childbirth

Background and ObjectiveChildbirth trauma is a major health concern that affects millions of women worldwide. Severe degrees of perineal trauma, designated as obstetric anal sphincter injuries (OASIS), and levator ani muscle (LAM) injuries are associated with long-term morbidity. While significant research has been conducted on LAM avulsions, less attention has been given to perineal trauma and OASIS, which affect up to 90% and 11% of vaginal deliveries, respectively. Despite being widely discussed, childbirth trauma remains unpredictable. This work aims to enhance the modeling of the maternal musculature during childbirth, with a particular focus on understanding the mechanisms underlying the often overlooked perineal injuries. MethodsA geometrical model of the pelvic floor muscles (PFM) and perineum (including the perineal body, ischiocavernosus, bulbospongiosus, superficial and deep transverse perineal muscles) was created. The muscles were characterized by a transversely isotropic visco-hyperelastic constitutive model. Two simulations of vaginal delivery were conducted with the fetus in the vertex presentation and occipito-anterior position, with and without the perineum. ResultsThe simulation that considered the perineum exhibited higher stresses over an extended area of the PFM, which suggests that including additional structures can impact the obtained results. The maximum stretch of the urogenital hiatus was 2.94 and the maximum stress was 23.86 kPa. The perineal body reached a maximum stretch of 1.95, which was more pronounced near the urogenital hiatus, where perineal tears may occur. The external anal sphincter's transverse diameter decreased by 51% and the maximum principal stresses were observed in the area close to the perineal body, where OASIS can occur. ConclusionsThe present study emphasizes the importance of including most structures involved in vaginal delivery in its biomechanical analysis and represents another step further in the understanding of perineal injuries and OASIS. The superior region of the perineal body and its connection to the urogenital hiatus and anal sphincter have been identified as the most critical regions, highly susceptible to injury.

OC18.05: Surgical outcome in women with advanced stage of pelvic organ prolapse: levator ani muscle avulsion and mesh application

OC18.05: Surgical outcome in women with advanced stage of pelvic organ prolapse: levator ani muscle avulsion and mesh application

Automated Segmentation of Levator Ani Muscle from 3D Endovaginal Ultrasound Images.

Levator ani muscle (LAM) avulsion is a common complication of vaginal childbirth and is linked to several pelvic floor disorders. Diagnosing and treating these conditions require imaging of the pelvic floor and examination of the obtained images, which is a time-consuming process subjected to operator variability. In our study, we proposed using deep learning (DL) to automate the segmentation of the LAM from 3D endovaginal ultrasound images (EVUS) to improve diagnostic accuracy and efficiency. Over one thousand images extracted from the 3D EVUS data of healthy subjects and patients with pelvic floor disorders were utilized for the automated LAM segmentation. A U-Net model was implemented, with Intersection over Union (IoU) and Dice metrics being used for model performance evaluation. The model achieved a mean Dice score of 0.86, demonstrating a better performance than existing works. The mean IoU was 0.76, indicative of a high degree of overlap between the automated and manual segmentation of the LAM. Three other models including Attention UNet, FD-UNet and Dense-UNet were also applied on the same images which showed comparable results. Our study demonstrated the feasibility and accuracy of using DL segmentation with U-Net architecture to automate LAM segmentation to reduce the time and resources required for manual segmentation of 3D EVUS images. The proposed method could become an important component in AI-based diagnostic tools, particularly in low socioeconomic regions where access to healthcare resources is limited. By improving the management of pelvic floor disorders, our approach may contribute to better patient outcomes in these underserved areas.

Obstetrical ballooning and avulsion of levator ani muscle after vaginal delivery: a literature review

Link of Video Abstract: https://youtu.be/TWDe9uP4QX8 The levator ani muscle (LAM) is thought to be of central importance concerning pelvic organ support. 10-30% of women experience overstretched or 'ballooning' of the levator hiatus, sometimes followed by detachment or 'avulsion' of the muscle from its insertion. Both ballooning and avulsion of the LAM can occur by itself or co-exist at the same time. This literature review was conducted on multiple databases from previous studies, to help clinicians better understand the ballooning and avulsion phenomenon, thus making early diagnosis possible for earlier prolapse prevention for the patients. LAM avulsion can be diagnosed clinically using digital palpation or using imaging modalities such as ultrasound and magnetic resonance imaging (MRI). During maximal contraction (or at rest) using ultrasound, levator avulsion is indicated through a levator-urethra gap (LUG) diameter &gt; 2.5 cm. MRI is considered highly sensitive, but it requires a higher cost and an experienced radiologist. Hiatal ballooning can be diagnosed by clinical examination based on the sum of Genital hiatus and Perineal body (Gh+Pb) and imaging with 2D, 3D, or 4D ultrasound during the Valsava maneuver. Ballooning is diagnosed clinically if Gh+Pb &gt; 7 cm, by 2D imaging of levator hiatal anteroposterior (LHAP) diameter ≥ 6 cm, and by 3D/4D imaging of the hiatal area ≥ 25 cm2. Physiotherapeutic treatment and pelvic floor muscle (PFM) exercises can be used to treat ballooning and LAM avulsion to avoid urogynecological sequelae. There is some evidence to prevent this condition, including vitamin D consumption, epidural analgesia, kegel exercise, and vaginal dilator. PFM strength, posterior vaginal wall support, and ultrasound evidence of LAM tear can be used as potential indicators to predict pelvic floor injury. Since ballooning and avulsion of the LAM have lifelong morbidity and are not often identified early by clinicians, further research is still needed.

Investigating antenatal pelvic floor training using a vaginal balloon device in Czech women

Background/Aims A vaginal balloon device for antenatal pelvic floor training may reduce the incidence of negative outcomes from vaginal birth on women's pelvic health. This study's aims were to investigate the effect of antenatal vaginal training on birth-induced levator ani muscle avulsion and to analyse the relationship between use of a balloon device for training and the duration of the second stage of labour, incidence of episiotomy and birth-induced perineal trauma. Methods In this prospective cohort intervention study, 123 nulliparous women were divided into two groups: 64 training with the device antenatally (intervention) and 59 women receiving normal antenatal care (control). Clinical data were collected 10 weeks after birth and differences in the incidence of levator ani muscle avulsion, episiotomy, perineal tears and other birth injuries, as well as the duration of the second stage of labour, were assessed using two-tailed tests. Results Training with the device was not associated with a reduction in the incidence of levator ani muscle avulsions (P=0.82), and the device did not shorten the duration of the second stage of labour (P=0.63). However, it was associated with a reduction in the frequency of episiotomies (cases: 34% vs controls: 59%; P=0.007). There was no significant difference in the incidence of perineal tears (P=1.00) or other birth injuries (P=0.50). An obstetric anal sphincter injury occurred in only one case, in a woman in the control group. Conclusions The use of an antenatal training device in nulliparous women with cephalic vaginal birth at term is not associated with better pelvic health outcomes. However, it may reduce the frequency of episiotomies.

Diagnostic test accuracy of magnetic resonance imaging and pelvic floor ultrasound for diagnosis of levator ani muscle avulsion.

To estimate the diagnostic test accuracy of magnetic resonance imaging (MRI) and pelvic floor ultrasound for levator ani muscle (LAM) avulsion in a general parous population, with view to establishing if ultrasound could substitute for MRI to diagnose LAM avulsion. This was a cross-sectional study of 135 women 4 years after their first delivery. Signs and symptoms of pelvic floor dysfunction were assessed using validated methods. All women underwent four-dimensional transperineal ultrasound (TPUS), three-dimensional endovaginal ultrasound (EVUS) and MRI. Images were acquired at rest, on pelvic floor muscle contraction (PFMC) and on maximum Valsalva maneuver, and analyzed by two blinded observers. Predefined cut-off values were used to diagnose LAM avulsion. In the absence of a reference standard, latent class analysis (LCA) was used to establish diagnostic test characteristics for LAM avulsion as the primary outcome measure. Secondary outcomes were kappa (κ) agreement between imaging techniques, intraclass correlation coefficients (ICC) for hiatal measurements at rest, on PFMC and on maximum Valsalva maneuver, and the association of LAM avulsion with signs and symptoms of pelvic floor dysfunction. The prevalence of LAM avulsion was 23.0% for MRI, 11.1% for TPUS and 17.8% for EVUS. The prevalence of LAM avulsion using LCA was 15.7%. The sensitivity for LAM avulsion of TPUS (71% (95% CI, 50-90%)) and EVUS (91% (95% CI, 74-100%)) was lower than that of MRI (100% (95% CI, 84-100%)). The specificity of TPUS (100% (95% CI, 97-100%)) and EVUS (95% (95% CI, 91-99%)) was higher than that of MRI (91% (95% CI, 85-97%)). MRI and EVUS had high predictive values for the assessment of major LAM avulsion (positive predictive value (PPV), 95% and negative predictive value (NPV), 100%; PPV, 100% and NPV, 98%, respectively), while TPUS had high predictive values for minor LAM avulsion (PPV, 100% and NPV, 95%). Major LAM avulsion on MRI and EVUS was associated with anterior vaginal wall prolapse, which was not found for TPUS. The agreement in the diagnosis of LAM avulsion (κ, 0.69) and hiatal measurements (ICC, 0.60-0.81) was highest between MRI and EVUS. Pelvic floor ultrasound can be implemented as a triage test to assess parous women for LAM avulsion because of its high specificity. Ultrasound cannot substitute for MRI because of its lower sensitivity. The predictive ability of ultrasound is moderate for the presence, and very good for the absence, of LAM avulsion. A positive test should be confirmed by a different observer or imaging technique. © 2022 International Society of Ultrasound in Obstetrics and Gynecology.

The clinical application of transperineal ultrasound in urogynaecology

Key content Transperineal ultrasound allows reproducible imaging of pelvic floor conditions that aids in the thorough assessment required to diagnose and treat urogynaecological conditions. Views that can be obtained include two‐dimensional (2D) sagittal views of the bladder neck, urethra and pelvic floor; 2D coronal views of the anal canal; and three‐dimensional (3D) or four‐dimensional (4D) views of the genital hiatus and anal canal. This allows assessment of the post‐void residual volumes, detrusor wall thickness and dynamic assessment of the urethral morphology. Ultrasonographic assessment enables accurate information about maternal birth trauma to be ascertained, including levator ani muscle avulsion and obstetric anal sphincter injury. Transperineal ultrasound can be used to identify and assess previously implanted vaginal mesh and midurethral slings. Learning objectives To understand the role of ultrasound in clinical urogynaecology practice, including the assessment of slings and meshes. To know the ultrasound probes, techniques and views used to image the pelvic floor and anal sphincters by transperineal ultrasound. To describe assessment of the lower urinary tract, pelvic organ prolapse and obstetric anal sphincter injury using ultrasound. Ethical issues Thorough assessment of the pelvic floor is mandatory against the background of technological advances in the investigation of pelvic floor dysfunction. As a common and major complication of childbirth, maternal birth trauma must be assessed fully to support primary and secondary prevention. Thorough assessment must underlie the use of mesh implants, and dealing with sling and mesh complications is enhanced by imaging.

Transvaginal Two-Dimensional Ultrasound Evaluation as a Screening Tool for Levator ani Muscle Avulsion in Postpartum Women.

To evaluate the agreement between two-dimensional transvaginal ultrasound (2D-TVUS) and transperineal tomographic ultrasound imaging on three-dimensional (3D) volume in diagnosing levator ani muscle (LAM) avulsion of postpartum women. Furthermore, we tested the repeatability of the 2D-TVUS in measuring the LAM thickness. A retrospective study was performed using the data sets from postpartum women. One doctor measured the thickness of the LAM on the images at the attachment to the arcus tendinous levator ani and the middle part using the 2D-TVUS ultrasound data sets of postpartum women. These women were examined twice, at 42-56 days and 3-6 months postpartum. Intra-observer repeatability was expressed using intraclass correlation coefficients (ICCs). The other doctor judged whether there was avulsion in the LAM on the 2D-TVUS and transperineal tomography imaging on the 3D volume. The inter-method agreement was determined using Cohen's kappa coefficient (k). Thickness measurements of the middle part and attachment of the LAM by 2D-TVUS showed excellent and good intra-observer repeatability (ICC 0.84; 95% CI, 0.76-0.88, and ICC 0.74; 95% CI, 0.67-0.84, respectively). The overall agreement was 92% (Cohen's kappa was 0.79) between 2D-TVUS and transperineal tomographic imaging. Compared to transperineal tomographic imaging in the diagnosis of LAM avulsion, the diagnostic sensitivity of 2D-TVUS was 91.7%, the specificity was 92.1%. The 2D-TVUS technique, a simple and reproducible method for assessing LAM avulsion, may be helpful as a screening tool for LAM avulsion of postpartum women.

Diagnosis of Levator Ani Muscle Avulsion in Instrumented Delivery: Meta-analysis

Objective: The objective of this meta-analysis was to establish the rates of levator ani muscle (LAM) avulsion in patients after forceps delivery (FD) and vacuum delivery (VD) as assessed by 3D/4D transperineal ultrasound. Methods: A systematic search was performed in the MEDLINE, PubMed, Google Scholar, and Embase databases up to December 31, 2021. Studies that studied primiparous women diagnosed with LAM avulsion by 3D/4D transperineal ultrasound in VD or FD were included. To do the meta-analysis, the jamovi project program version 2.2 (2021) was used. Results: The search yielded 1225 studies that met the MeSH criteria, of which 26 were included in the review. The estimated joint OR for VD vs. normal vaginal delivery (NVD) was 1.93 (95% CI: 1.31–2.86), for FD vs. NVD was 5.33 (95% CI: 3.78–8.11), and for FD vs. VD was 2.36 (95% CI: 1.46–3.84). Conclusions: Instrumented delivery with forceps or vacuum favors LAM avulsion. It is not possible to establish whether this injury is attributable to the specific instrument or to the type of delivery involved in the instrumentation itself.

The Role of Transperineal Ultrasound for the Assessment of the Anorectal Angle and Its Relationship with Levator Ani Muscle Avulsion.

The relationship between the anorectal angle (ARA) and the levator ani muscle (LAM) is well known. In this study, we aimed to demonstrate that the ARA changes when LAM avulsion occurs after vaginal delivery. This was a secondary, observational retrospective study with data obtained from three previous studies. Using transperineal ultrasound, the presence of avulsion was assessed when abnormal insertion of the LAM was observed in three central slices. In addition, the ARA was assessed in the midsagittal plane (at rest, in Valsalva and at maximum contraction) as the angle between the posterior border of the distal part of the rectum and the central axis of the anal canal. The ARA was higher in patients with bilateral LAM avulsion than in patients without LAM avulsion at rest (131.8 ± 14.1 vs. 136.2 ± 13.8), in Valsalva (129.4 ± 15.5 vs. 136.5 ± 14.4) and at maximum contraction (125.7 ± 15.5 vs. 132.3 ± 13.2). The differences between both groups expressed as the odds ratio (OR) adjusted for maternal age were 1.031 (95% confidence interval (CI), 1.001–1.061; p = 0.041) at rest, 1.036 (95% CI, 1.008–1.064; p = 0.012) in Valsalva and 1.031 (95% CI, 1.003–1.059; p = 0.027) at maximum contraction. In conclusion, LAM avulsion produces an increase in the ARA at rest, during contraction and in Valsalva, especially in cases of bilateral LAM avulsion.

Is age at menarche a predictor of maternal birth trauma?

Age at menarche and the interval between menarche and age at first vaginal birth have been shown to be associated with reproductive performance; however, their association with maternal birth trauma has not been studied. We aimed to determine whether age at menarche, age at first vaginal birth and their interval are associated independently with levator ani muscle (LAM) avulsion and external anal sphincter (EAS) defect. This was a retrospective analysis of the ultrasound volume datasets of 466 vaginally parous patients attending one of two tertiary urogynecological units in Australia. All patients had undergone a standardized interview and clinical examination using the pelvic organ prolapse quantification staging system, followed by four-dimensional translabial ultrasound. Tomographic ultrasound imaging was used to evaluate the LAM for avulsion and the EAS for significant defect. Of the 466 women analyzed, LAM avulsion was diagnosed in 121 (26.0%) and significant EAS defect in 55 (11.8%). Logistic regression analysis showed no association between age at menarche and LAM avulsion (P = 0.67). Weak but significant associations were noted between LAM avulsion and age at first vaginal birth (odds ratio (OR), 1.070 (95% CI, 1.03-1.11); P = 0.0007) and between LAM avulsion and menarche-to-first-vaginal-birth interval (OR, 1.064 (95% CI, 1.02-1.11); P = 0.0018). No significant associations were noted between significant EAS defect and any of the evaluated variables (all P ≥ 0.49). Age at menarche is not predictive of maternal birth trauma i.e. LAM avulsion and EAS residual defect. There was a statistically significant association between LAM avulsion and menarche-to-first-vaginal-birth interval; however, this was not stronger than the previously established association between LAM avulsion and age at first vaginal birth, arguing against any distinct effect of prolonged prepregnancy hormonal stimulation on the biomechanical properties of the pelvic floor. © 2021 International Society of Ultrasound in Obstetrics and Gynecology.

A biomechanical study of the birth position: a natural struggle between mother and fetus.

Birth trauma affects millions of women and infants worldwide. Levator ani muscle avulsions can be responsible for long-term morbidity, associated with 13-36% of women who deliver vaginally. Pelvic floor injuries are enhanced by fetal malposition, namely persistent occipito-posterior (OP) position, estimated to affect 1.8-12.9% of pregnancies. Neonates delivered in persistent OP position are associated with an increased risk for adverse outcomes. The main goal of this work was to evaluate the impact of distinct fetal positions on both mother and fetus. Therefore, a finite element model of the fetal head and maternal structures was used to perform childbirth simulations with the fetus in the occipito-anterior (OA) and OP position of the vertex presentation, considering a flexible-sacrum maternal position. Results demonstrated that the pelvic floor muscles' stretch was similar in both cases. The maximum principal stresses were higher for the OP position, and the coccyx rotation reached maximums of 2.17[Formula: see text] and 0.98[Formula: see text] for the OP and OA positions, respectively. Concerning the fetal head, results showed noteworthy differences in the variation of diameters between the two positions. The molding index is higher for the OA position, with a maximum of 1.87. The main conclusions indicate that an OP position can be more harmful to the pelvic floor and pelvic bones from a biomechanical point of view. On the other side, an OP position can be favorable to the fetus since fewer deformations were verified. This study demonstrates the importance of biomechanical analyses to further understand the mechanics of labor.