Prevalence of levator ani muscle injuries in primiparous women after delivery and their influence on pelvic floor disorders-systematic review.

BACKGROUND: Studies show a significant association between the first vaginal delivery and injuries of the levator ani muscle (LAM), which can cause pelvic floor disorders (PFDs). OBJECTIVES: This study aims to identify the prevalence of short and long-term LAM injuries after vaginal delivery in primiparous women and its influence on PFDs. METHOD: A systematic review was conducted according to the PRISMA methodology. The databases used were Pubmed, Cochrane, and PEDro. The quality assessment of the evidence was carried out using the Critical Appraisal Skills Programme (CASP). Both the selection of studies and their evaluation were done by two researchers and a third reviewer in cases of disagreement. RESULTS: From the search, 57 articles were gathered, and 19 were included to match the eligibility criteria. The prevalence of avulsion of the LAM was found in association with vaginal delivery between 13% and 28% ≤ 1 year after delivery and between 16% and 29% > 1 year after delivery. Ballooning was detected between 20% and 37% ≤ 1 year, and 33% of women > 1 year after delivery, appearing to be more common when compared to avulsion. Pelvic organ prolapse (POP) was considered the most common disorder associated with injuries of the LAM, and there seems to be some connection with sexual dysfunction. CONCLUSION: Avulsion of the LAM and ballooning of the hiatal area have a high prevalence in primiparous women after vaginal delivery and have a strong direct relation to the development of POP.

Pre- vs Post-Operative Levator Ani Subtended Volume in Patients Undergoing Hysterectomy: A Comparative Imaging Study.

INTRODUCTION AND HYPOTHESIS: The effects of hysterectomy on pelvic floor function remain uncertain, with the levator ani muscle (LAM) playing a critical role in pelvic support. The levator ani subtended volume (LASV) is an objective measure of the LAM's anatomical volume, derived from magnetic resonance imaging (MRI). This study was aimed at assessing the consistency between MRI and computed tomography (CT) in quantifying LASV, and to investigate the effect of hysterectomy on the LAM. METHODS: This retrospective study analyzed a cohort of 55 hysterectomy patients, utilizing pre-operative pelvic MRI and post-operative CT scans to measure the LASV. To evaluate the consistency between MRI and CT, the study employed the intraclass correlation coefficient and Bland-Altman agreement analysis in a subset of 32 patients with both pre-operative scans. A paired-samplet test was used to analyze LASV changes pre- and post-hysterectomy, and linear regression analysis was performed to account for potential risk factors that may influence post-operative LASV. RESULTS: High consistency between MRI and CT in measuring LASV was found, with an ICC of 0.911. We observed a significant increase in LASV following hysterectomy, with mean volume pre- and post-operatively of 16.66 cm3 and 18.87 cm3 respectively. Age and body mass index were significant predictors of post-hysterectomy LASV, whereas parity and the type of hysterectomy had no significant impact. CONCLUSIONS: Hysterectomy significantly affects the LAM, resulting in an increase in post-operative LASV. Moreover, this study verifies that MRI and CT can be used interchangeably for LASV measurements in clinical practice.

Applicability of Deep Learning to Dynamically Identify the Different Organs of the Pelvic Floor in the Midsagittal Plane.

INTRODUCTION AND HYPOTHESIS: The objective was to create and validate the usefulness of a convolutional neural network (CNN) for identifying different organs of the pelvic floor in the midsagittal plane via dynamic ultrasound. METHODS: This observational and prospective study included 110 patients. Transperineal ultrasound scans were performed by an expert sonographer of the pelvic floor. A video of each patient was made that captured the midsagittal plane of the pelvic floor at rest and the change in the pelvic structures during the Valsalva maneuver. After saving the captured videos, we manually labeled the different organs in each video. Three different architectures were tested-UNet, FPN, and LinkNet-to determine which CNN model best recognized anatomical structures. The best model was trained with the 86 cases for the number of epochs determined by the stop criterion via cross-validation. The Dice Similarity Index (DSI) was used for CNN validation. RESULTS: Eighty-six patients were included to train the CNN and 24 to test the CNN. After applying the trained CNN to the 24 test videos, we did not observe any failed segmentation. In fact, we obtained a DSI of 0.79 (95% CI: 0.73 - 0.82) as the median of the 24 test videos. When we studied the organs independently, we observed differences in the DSI of each organ. The poorest DSIs were obtained in the bladder (0.71 [95% CI: 0.70 - 0.73]) and uterus (0.70 [95% CI: 0.68 - 0.74]), whereas the highest DSIs were obtained in the anus (0.81 [95% CI: 0.80 - 0.86]) and levator ani muscle (0.83 [95% CI: 0.82 - 0.83]). CONCLUSIONS: Our results show that it is possible to apply deep learning using a trained CNN to identify different pelvic floor organs in the midsagittal plane via dynamic ultrasound.

Evaluation and management of chronic anorectal and pelvic pain syndromes: Italian Society of Colorectal Surgery (SICCR) position statement.

Chronic pelvic pain is a hidden issue which needs to involve many different usually uncoordinated specialists. For this reason there is a risk that treatments, in the absence of well-defined pathways, common goals, and terminology, may be poorly effective. The aim of the present paper is to summarize the evidence on anorectal pelvic pain, offering useful evidence-based practice parameters for colorectal surgeons' daily activity. Analysis of chronic anorectal and pelvic pain syndromes, the diagnostic and clinical optimal needs for evaluation, and the innumerable low evidence treatments and therapeutic options currently available suggests that a multimodal individualized management of pain may be the most promising approach. The limited availability of dedicated centers still negatively affects the applicability of these principles.

Quantitative 3D Analysis of Levator Ani Muscle Subdivisions in Nulliparous Women: MRI Feasibility Study.

BACKGROUND: The levator ani muscle (LAM) is crucial for pelvic floor stability, yet its quantitative MRI assessment is only a recent focus. Our study aims to standardize the quantitative analysis of the LAM morphology within the 3D Pelvic Inclination Correction System (3D-PICS). METHODS: We analyzed 35 static MR datasets from nulliparous women examining the pubovisceral (PVM), iliococcygeal (ICM), coccygeal (COC), and puborectal muscle (PRM). The PVM consists of three origin-insertion pairs, namely the puboanal (PAM), puboperineal (PPM) and pubovaginal muscle (PVaM). The analysis included a quantitative examination of the morphology of LAM, focusing on the median location (x/y/z) (x: anterior-posterior, y: superior-inferior, z: left-right) of the origin and insertion points (a), angles (b) and lengths (c) of LAM. Inter-rater reliability was calculated. RESULTS: Interindividual variations in 3D coordinates among muscle subdivisions were shown. In all, 93% of all origin and insertion points were found within an SD of <8 mm. Angles to the xz-plane range between -15.4° (right PRM) and 40.7° (left PAM). The PRM is the largest pelvic muscle in static MRI. The ICC indicated moderate-to-good agreement between raters. CONCLUSIONS: The accurate morphometry of the LAM and its subdivisions, along with reliable inter-rater agreement, was demonstrated, enhancing the understanding of normal pelvic anatomy in young nulliparous women.

Coronal Plane Assessment for Levator Trauma.

OBJECTIVE: Levator avulsion is a major etiological factor of pelvic organ prolapse (POP) and is primarily diagnosed on tomographic axial plane imaging. Two-dimensional imaging can also image the levator. The objective was to test reproducibility and validity of coronal plane assessment for diagnosis of levator trauma by assessing the coronal plane obtained on tomographic ultrasound imaging. METHODS: A retrospective study of women who had undergone an interview, POPQ and four-dimensional translabial ultrasound at a tertiary urogynecological unit. Post-processing of archived volume data was performed for assessment; and levator muscle area and estimate of remnant muscle mass in the coronal plane. Interobserver reproducibility of the latter two measures and associations between various measures of levator trauma and POP were tested. RESULTS: Interobserver agreement was good for percentage estimates (ICC 0.743), but fair for area measurements (ICC 0.482). Six hundred and twenty four women were seen, 468 (75%) had significant clinical prolapse. Full levator avulsions were diagnosed in 137 (22%). Mean TTS was 2.7 (range 0-12). On coronal plane assessment average muscle area was 1.47 (SD 0.76) cm2 and 1.55 (SD 0.74) cm2 on the right and left, respectively (P = .005). It was 76% and 79% for average estimates of muscle mass (P = .021). Both measures were strongly associated with POP; however, they were not superior to TTS in predicting POP. CONCLUSION: Coronal plane assessment in volume data is reproducible and valid for evaluation of levator trauma. Muscle mass estimate may be a better measure than muscle area.

Advancements in artificial intelligence for pelvic floor ultrasound analysis.

Pelvic floor ultrasound provides a clear depiction of pelvic floor structures and their spatial anatomical relationships, enabling enhanced observation of pelvic organ function and position. The integration of artificial intelligence (AI) into medical imaging has revolutionized the automatic analysis of imaging data, offering efficient and accurate preprocessing and analysis. This technological advance addresses challenges associated with traditional pelvic floor ultrasound, such as reliance on operator's experience, time-intensive manual measurements, and significant potential for human error. Current AI applications in pelvic floor ultrasound encompass automatic measurement of the angle of progress (AOP), automatic segmentation of the levator hiatus (LH), and automatic identification of the levator ani muscle (LAM). AI excels in mimicking human analysis, distilling patterns from reorganized data. This paper, grounded in a comprehensive literature review, outlines the principal aspects of pelvic floor ultrasound and its augmentation through AI, highlighting the application value and progress of AI in this field.

Exploring transvaginal sonographic characteristics of the levator ani muscle in women with postpartum pelvic floor myofascial pain.

BACKGROUND: Pelvic floor myofascial pain is one of the pelvic floor dysfunction diseases disturbing women after delivery. There is a lack of objective standardization for the diagnosis of pelvic floor myofascial pain due to the various symptoms and the dependence on the palpating evaluation. Ultrasound imaging has the advantages of safety, simplicity, economy and high resolution, which makes it an ideal tool for the assistant diagnosis of pelvic floor myofascial pain and evaluation after treatment. METHODS: This is a retrospective case-control study including women accepting evaluation of pelvic floor function at 6 weeks to 1 year postpartum. They were divided into pelvic floor myofascial pain group and normal control group. A BCL 10-5 biplane transducer was applied to observed their puborectalis. The length, minimum width, area, deficiency, deficiency length, deficiency width, deficiency area, rate of deficiency area, local thickening,angle between the tendinous arch of levator ani muscle and puborectalis of corresponding puborectalis in different groups were observed and measured. RESULTS: A total of 220 postpartum women participated in the study, with 77 in the pelvic floor myofascial pain group and 143 in the normal control group. The Intraclass correlation coefficient value was over 0.750, and Kappa ranged from 0.600 to 0.800. puborectalis deficiency (adjusted odds ratio = 11.625, 95% confidence interval = 4.557-29.658) and focal thickening (adjusted odds ratio = 16.891, 95% confidence interval = 1.819-156.805) were significantly associated with higher odds of having postpartum pelvic floor myofascial pain. Grayscale or the angle between the arch tendineus levator ani and puborectalis measurements on the pain side tended to be smaller than on the non-pain side in patients with unilateral puborectalis or iliococcygeus pain (P < 0.05). CONCLUSIONS: This study demonstrated that transvaginal ultrasound was a potentially efficient technique for evaluating postpartum pelvic floor myofascial pain due to its ability to assess various sonographic characteristics of the levator ani muscles.

Shift from Pro- to Anti-Inflammatory Phase in Pelvic Floor Muscles at Postpartum Matches Histological Signs of Regeneration in Multiparous Rabbits.

Background and Objectives: Pelvic floor muscles (PFM) play a core role in defecation and micturition. Weakening of PFM underlies urogynecological disorders such as pelvic organ prolapse and stress urinary incontinence. Vaginal delivery damages PFM. Muscle trauma implies an inflammatory response mediated by myeloid cells, essential for subsequent recovery. Molecular signaling characterizing the pro-inflammatory phase shifts M1 macrophages to M2 macrophages, which modulate muscle repair. The present study aimed to evaluate histological characteristics and the presence of M1 and M2 macrophages in bulbospongiosus (Bsm) and pubococcygeus muscles (Pcm). Materials and Methods: Muscles from young nulliparous (N) and multiparous rabbits on postpartum days three (M3) and twenty (M20) were excised and histologically processed to measure the myofiber cross-sectional area (CSA) and count the centralized myonuclei in hematoxylin-eosinstained sections. Using immunohistochemistry, M1 and M2 macrophages were estimated in muscle sections. Kruskal-Wallis or one-way ANOVA testing, followed by post hoc tests, were conducted to identify significant differences (p < 0.05). Results: The myofiber CSA of both the Bsm and Pcm of the M3 group were more extensive than those of the N and M20 groups. Centralized myonuclei estimated in sections from both muscles of M20 rabbits were higher than those of N rabbits. Such histological outcomes matched significant increases in HLA-DR immunostaining in M3 rabbits with the CD206 immunostaining in muscle sections from M20 rabbits. Conclusions: A shift from the pro- to anti-inflammatory phase in the bulbospongiosus and pubococcygeus muscles of multiparous rabbits matches with centralized myonuclei, suggesting the ongoing regeneration of muscles.

Parturition at term: induction, second and third stages of labor, and optimal management of life-threatening complications-hemorrhage, infection, and uterine rupture.

Childbirth is a defining moment in anyone's life, and it occurs 140 million times per year. Largely a physiologic process, parturition does come with risks; one mother dies every two minutes. These deaths occur mostly among healthy women, and many are considered preventable. For each death, 20 to 30 mothers experience complications that compromise their short- and long-term health. The risk of birth extends to the newborn, and, in 2020, 2.4 million neonates died, 25% in the first day of life. Hence, intrapartum care is an important priority for society. The American Journal of Obstetrics & Gynecology has devoted two special Supplements in 2023 and 2024 to the clinical aspects of labor at term. This article describes the content of the Supplements and highlights new developments in the induction of labor (a comparison of methods, definition of failed induction, new pharmacologic agents), management of the second stage, the value of intrapartum sonography, new concepts on soft tissue dystocia, optimal care during the third stage, and common complications that account for maternal death, such as infection, hemorrhage, and uterine rupture. All articles are available to subscribers and non-subscribers and have supporting video content to enhance dissemination and improve intrapartum care. Our hope is that no mother suffers because of lack of information.

Soft-tissue dystocia due to paradoxical contraction of the levator ani as a cause of prolonged second stage: concept, diagnosis, and potential treatment.

Smaller pelvic floor dimensions seem to have been an evolutionary need to provide adequate support for the pelvic organs and the fetal head. Pelvic floor dimension and shape contributed to the complexity of human birth. Maternal pushing associated with pelvic floor muscle relaxation is key to vaginal birth. Using transperineal ultrasound, pelvic floor dimensions can be objectively measured in both static and dynamic conditions, such as pelvic floor muscle contraction and pushing. Several studies have evaluated the role of the pelvic floor in labor outcomes. Smaller levator hiatal dimensions seem to be associated with a longer duration of the second stage of labor and a higher risk of cesarean and operative deliveries. Furthermore, smaller levator hiatal dimensions are associated with a higher fetal head station at term of pregnancy, as assessed by transperineal ultrasound. With maternal pushing, most women can relax their pelvic floor, thus increasing their pelvic floor dimensions. Some women contract rather than relax their pelvic floor muscles under pushing, which is associated with a reduction in the anteroposterior diameter of the levator hiatus. This phenomenon is called levator ani muscle coactivation. Coactivation in nulliparous women at term of pregnancy before the onset of labor is associated with a higher fetal head station at term of pregnancy and a longer duration of the second stage of labor. In addition, levator ani muscle coactivation in nulliparous women undergoing induction of labor is associated with a longer duration of the active second stage of labor. Whether we can improve maternal pelvic floor relaxation with consequent improvement in labor outcomes remains a matter of debate. Maternal education, physiotherapy, and visual feedback are promising interventions. In particular, ultrasound visual feedback before the onset of labor can help women increase their levator hiatal dimensions and correct levator ani muscle coactivation in some cases. Ultrasound visual feedback in the second stage of labor was found to help women push more efficiently, thus obtaining a lower fetal head station at ultrasound and a shorter duration of the second stage of labor. The available evidence on the role of any intervention aimed to aid women to better relax their pelvic floor remains limited, and more studies are needed before considering its routine clinical application.

Systematic Review and Meta-analysis of the Prevalence of Levator Ani Avulsion with Obstetric Anal Sphincter Injury and its Effects on Pelvic Floor Dysfunction.

INTRODUCTION AND HYPOTHESIS: The objective was to evaluate the prevalence of levator ani avulsion (LAA) among primiparous women with obstetric anal sphincter injury (OASI) and how this association could affect future pelvic floor dysfunction. METHODS: Three electronic databases (MEDLINE/PubMed/EMBASE) were searched in December 2018 and again in October 2022. Nine full-text articles were included in the analysis. The exclusion criteria were language other than English, studies not based on primiparous women only, conference abstracts, and evaluation without ultrasound or MRI. RESULTS: The overall prevalence of LAA was 24% (95% CI: 18-30%). Those with OASI, were at a higher risk of LAA, OR 3.49 (95% CI: 1.46 to 8.35). In women with LAA + OASI versus OASI alone, Three of Five studies showed worsened AI symptoms. Three of Five studies assessing urinary incontinence (UI) reported no significant difference in UI, whereas two reported increased UI. All studies that looked at pelvic organ prolapse reported a higher incidence of symptomatic prolapse and reduced pelvic floor muscle strength in women with LAA + OASI compared with those without LAA. CONCLUSION: Levator ani avulsion is prevalent following vaginal birth and is strongly associated with OASI. Incidence of AI does not increase in women with LAA and OASI, but they had greater symptom bother. OASI with LAA appears to increase the incidence of pelvic floor weakness and pelvic organ prolapse. There is no consensus agreement on the effect of LAA + OASI on UI.

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

OBJECTIVES: Women 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 DESIGN: OVID 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. RESULTS: Twenty-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]). CONCLUSIONS: This 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.

The predicting value of the ratio of levator hiatus diameter to fetal head circumference in pregnant women at 37 weeks of gestation in the progression of the second stage of labor and levator ani injury 6 weeks postpartum.

Objective: This study investigated the predicting value of the ratio of levator hiatus diameter (LHS) to fetal head circumference (HC) in pregnant women at 37 weeks of gestation in the progression of the second stage of labor and levator ani injury 6 weeks postpartum. Methods: A total of 120 first-time women who gave vaginal delivery at 37 weeks of pregnancy were selected as the subjects in our hospital during March 2021 to March 2022. The subjects were divided into the second stage of labor > 1 h group and the second stage of labor ≤ 1 h group, according to the delivery time of the second stage of labor. According to the 6-week postpartum follow-up ultrasound examination with or without levator ani injury, they were divided into levator ani injury group and no injury group. All primipara women underwent three-dimensional ultrasonography at 37 weeks of gestation, and the resting LHS, Valsalva LHS, fetal HC and the ratio of resting LHS and fetal HC were compared. The correlation between these factors and the length of the second labor stage was analyzed using Pearson correlation analysis. The value of these factors in predicting labor progression and postpartum levator ani injury was assessed by receiver operating characteristic (ROC) curves. Results: The resting LHS, Valsalva LHS and the ratio of resting LHS and fetal HC in the levator ani injury group were lower than these in the no injury group, while fetal HC in the levator ani injury group was higher than that in the no injury group (P < 0.05). The resting LHS, Valsalva LHS and the ratio of resting LHS and fetal HC in the second stage of labor > 1 h group were lower than these in the second stage of labor ≤ 1 h group, while fetal HC in the second stage of labor > 1 h group was higher than that in the second stage of labor ≤ 1 h group (P < 0.05). A significant negative correlation was observed between resting LHS/HC and total labor process (=-0.333, P < 0.01). ROC curve analysis showed that the AUCs of resting LHS, Valsalva LHS, HC, and resting LHS/HC ratio in predicting prolongation of the second stage of labor were 0.741, 0.740, 0.702, and 0.843 respectively. Besides, the AUCs of resting LHS, Valsalva LHS, HC, and resting LHS/HC ratio in predicting the total labor process were 0.657, 0.684, 0.768, and 0.836 respectively. The AUCs of resting LHS, Valsalva LHS, HC, and resting LHS/HC ratio in predicting postpartum levator ani muscle injury were 0.769, 0.773, 0.747, and 0.885 respectively.These results suggested that the ratio of resting LHS and fetal HC may have certain clinical value in predicting levator ani injury in pregnant women. Conclusion: LHS, fetal HC and the ratio of resting LHS and fetal HC are significantly correlated with labor progression and postpartum levator ani injury, which have certain value in predicting labor progress and postpartum levator ani injury. Therein, the ratio of resting LHS and fetal HC has the highest predictive value, and early detection of the ratio of resting LHS and fetal HC is helpful to guide the selection of appropriate delivery mode.

Feasibility and reproducibility of new technique for measurement of transverse diameter of levator ani muscle hiatus using two-dimensional transperineal ultrasound in nulliparous women with term pregnancy.

OBJECTIVES: The aim of the present study was two-fold. Firstly, we aimed to develop and describe a technique for measurement of the transverse diameter (TD) of the levator ani muscle (LAM) hiatus in the coronal view using two-dimensional (2D) transperineal ultrasound (TPUS) in nulliparous women with a term pregnancy. Secondly, we aimed to evaluate the feasibility and reproducibility of 2D-TPUS assessment of LAM hiatal TD and assess intermethod agreement between 2D-TPUS and three-dimensional (3D) TPUS measurement of TD in the axial plane, which is considered the gold standard in nulliparous women with term pregnancy. METHODS: We recruited a group of nulliparous women with term pregnancy before the onset of labor. The study was conducted in two phases: Phase 1 involved developing and describing the 2D-TPUS technique for measuring LAM hiatal TD, and Phase 2 focused on assessing the technique's feasibility, reproducibility and intermethod agreement with 3D-TPUS measurement of LAM hiatal TD. In Phase 1, we enrolled 30 women. Each woman underwent acquisition of a 3D-TPUS volume, which was analyzed using multiplanar mode to identify and determine the appearance of the lateral borders of the LAM in the coronal plane, at the level of the plane of minimal hiatal dimensions. These borders were used as landmarks for TD measurement. Additionally, we measured the distance between the plane used for TD measurement and the center of the urethra in the axial view. In Phase 2, we recruited 100 women. Each woman underwent acquisition of three 2D-TPUS videoclips in the coronal plane, each encompassing a sweep of the entire LAM hiatus, and a 3D volume, all obtained during rest. On the 2D videoclips, TD was measured twice by one operator and once by another operator. In the 3D volume, TD was measured once, by one operator, in the axial plane; this measurement was considered the gold standard. Each operator was blinded to all other measurements during their assessments. We analyzed intraobserver and interobserver reproducibility and performed an intermethod (2D vs 3D) comparison. Bland-Altman analysis was conducted, and Levene's W0 test and Student's t-test were performed to explore clinical factors that might contribute to systematic differences. RESULTS: In Phase 1, we identified successfully the landmarks denoting the lateral borders of the LAM hiatal TD in the coronal view. These appeared as two symmetrical hypoechogenic indentations located at the inner border of the hyperechogenic structure of the LAM, at the point of maximum distance between the two sides of the LAM. The distance between the urethra and the plane where TD should be measured using 3D-TPUS in the axial plane had a median of 4 mm and varied from 0 to 9 mm. This enabled us to describe a method for assessing LAM hiatal TD in the coronal plane using 2D-TPUS. In Phase 2, LAM hiatal TD was measured successfully in all 2D and 3D acquisitions from the entire group of 100 women. The analyses for intraobserver and interobserver reproducibility and the intermethod comparison (2D vs 3D) revealed almost perfect agreement in TD measurements using 2D-TPUS, with intraclass correlation coefficients of 0.95 (95% CI, 0.92-0.96), 0.87 (95% CI, 0.78-0.92) and 0.85 (95% CI, 0.78-0.90), respectively. The average differences between measurements were 0.1 mm for intraobserver, 1.0 mm for interobserver and 0.2 mm for intermethod repeatability. No systematic differences were observed in any of the measurement sets, except in the interobserver analysis, although this difference was clinically not significant (38.2 vs 37.2 mm, P = 0.01). None of the examined clinical factors (maternal body mass index and maternal age) exhibited a statistically significant impact on intraobserver, interobserver or intermethod reliability. CONCLUSIONS: Utilizing our technique, described herein, to measure the LAM hiatal TD in the coronal view using 2D-TPUS is not only feasible but also highly reproducible and accurate in nulliparous women with term pregnancy. Moreover, it yields measurements that are comparable to those obtained in the reconstructed axial plane generated by 3D-TPUS. © 2024 International Society of Ultrasound in Obstetrics and Gynecology.

Volumetric segmentation analysis of the levator ani muscle using magnetic resonance imaging in pelvic floor function assessment

PURPOSE: In this case-control study, we aimed to evaluate how muscle volume affects pelvic floor function by analyzing the levator ani muscle (LAM) using volumetric segmentation in addition to standard magnetic resonance (MR) defecography assessments. METHODS: We enrolled 85 patients with varying degrees of pelvic floor dysfunction (PFD) and 85 age- and gender-matched controls in this retrospective study. All patients had MR defecography images, while all controls had pelvic MR images obtained for other reasons. Group comparisons were performed using independent samples t-tests and Mann-Whitney U tests. The receiver operating curve (ROC) was constructed to establish a cut-off value for a normal LAM volume. Interrater reliability was assessed by calculating the intraclass correlation coefficient. A P value of less than 0.05 was considered statistically significant. RESULTS: Volumetric measurements revealed that the control group had higher LAM volumes, and the ROC curve analysis indicated a cut-off value of 38934.3 mm3 with a sensitivity of 0.812 and specificity of 0.8 for PFD assessment using LAM volumetric measurement. Gender did not significantly affect LAM volume in the control group. CONCLUSION: Alongside the useful structural and functional information acquired from MR defecography images, volumetric analysis, and three-dimensional reconstructions of LAM may help to improve the accuracy of the diagnosis.

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

OBJECTIVES: 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. METHODS: 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. RESULTS: 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 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 8-year follow-up. All women with full avulsion at 1-year follow-up were diagnosed with full avulsion at 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. CONCLUSIONS: 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.

Pelvic floor injury during vaginal birth is life-altering and preventable: what can we do about it?

Pelvic floor disorders after childbirth have distressing lifelong consequences for women, requiring more than 300,000 women to have surgery annually. This represents approximately 10% of the 3 million women who give birth vaginally each year. Vaginal birth is the largest modifiable risk factor for prolapse, the pelvic floor disorder most strongly associated with birth, and is an important contributor to stress incontinence. These disorders require 10 times as many operations as anal sphincter injuries. Imaging shows that injuries of the levator ani muscle, perineal body, and membrane occur in up to 19% of primiparous women. During birth, the levator muscle and birth canal tissues must stretch to more than 3 times their original length; it is this overstretching that is responsible for the muscle tear visible on imaging rather than compression or neuropathy. The injury is present in 55% of women with prolapse later in life, with an odds ratio of 7.3, compared with women with normal support. In addition, levator damage can affect other aspects of hiatal closure, such as the perineal body and membrane. These injuries are associated with an enlarged urogenital hiatus, now known as antedate prolapse, and with prolapse surgery failure. Risk factors for levator injury are multifactorial and include forceps delivery, occiput posterior birth, older maternal age, long second stage of labor, and birthweight of >4000 g. Delivery with a vacuum device is associated with reduced levator damage. Other steps that might logically reduce injuries include manual rotation from occiput posterior to occiput anterior, slow gradual delivery, perineal massage or compresses, and early induction of labor, but these require study to document protection. In addition, teaching women to avoid pushing against a contracted levator muscle would likely decrease injury risk by decreasing tension on the vulnerable muscle origin. Providing care for women who have experienced difficult deliveries can be enhanced with early recognition, physical therapy, and attention to recovery. It is only right that women be made aware of these risks during pregnancy. Educating women on the long-term pelvic floor sequelae of childbirth should be performed antenatally so that they can be empowered to make informed decisions about management decisions during labor.

Functional Anatomy of Urogenital Hiatus Closure: the Perineal Complex Triad Hypothesis.

INTRODUCTION: Urogenital hiatus enlargement is a critical factor associated with prolapse and operative failure. This study of the perineal complex was performed to understand how interactions among its three structures: the levator ani, perineal membrane, and perineal body-united by the vaginal fascia-work to maintain urogenital hiatus closure. METHODS: Magnetic resonance images from 30 healthy nulliparous women with 3D reconstruction of selected subjects were used to establish overall geometry. Connection points and lines of action were based on perineal dissection in 10 female cadavers (aged 22-86 years), cross sections of 4 female cadavers (aged 14-35 years), and histological sections (cadavers aged 16 and 21 years). RESULTS: The perineal membrane originates laterally from the ventral two thirds of the ischiopubic rami and attaches medially to the perineal body and vaginal wall. The levator ani attaches to the perineal membrane's cranial surface, vaginal fascia, and the perineal body. The levator line of action in 3D reconstruction is oriented so that the levator pulls the medial perineal membrane cranio-ventrally. In cadavers, simulated levator contraction and relaxation along this vector changes the length of the membrane and the antero-posterior diameter of the urogenital hiatus. Loss of the connection of the left and right perineal membranes through the perineal body results in diastasis of the levator and a widened hiatus, as well as a downward rotation of the perineal membrane. CONCLUSION: Interconnections involving the levator ani muscles, perineal membrane, perineal body, and vaginal fascia form the perineal complex surrounding the urogenital hiatus in an arrangement that maintains hiatal closure.