Interrater reliability and physical examination of the pubovisceral portion of the levator ani muscle, validity comparisons using MR imaging

Levator-urethra gap: is there a need for individualization of cut-offs?

OBJECTIVES

To determine whether height, weight and body mass index (BMI) are associated with the levator-urethra gap (LUG) measurement, and whether these factors confound the relationship between LUG and symptoms and signs of pelvic organ prolapse (POP).

METHODS

This was a retrospective study of women seen at a tertiary urogynecology unit between January 2020 and December 2021. Postprocessing of saved ultrasound volume data was used to measure the LUG, blinded against all other data. This measurement was tested for its association with organ descent and hiatal area, and height, weight and BMI were investigated for any potential confounding effect.

RESULTS

The 624 women seen during the inclusion period presented mostly with stress urinary incontinence (448/624 (72%)), urgency urinary incontinence (469/624 (75%)) and/or prolapse (338/624 (54%)). Mean age at assessment was 58 (range, 20-94) years, mean height was 163 (range, 142-182) cm, mean weight was 80 (range, 41-153) kg and mean BMI was 30 (range, 17-65) kg/m2. LUG measurements could be obtained in 613 women, resulting in 7356 (12 × 613) measurements. The average LUG in individual women measured 2.35 cm on the right and 2.32 cm on the left side (difference not significant), with a mean ± SD of 2.34 ± 0.63 cm overall. Mean LUG was associated with symptoms and signs of prolapse, both on clinical examination (POP quantification system) and on imaging, but not with height (P = 0.36), weight (P = 0.20) or BMI (P = 0.09).

CONCLUSIONS

Levator-urethra gap measurements do not seem to be significantly associated with height, weight or BMI in our population, obviating the need for individualization of LUG. However, this does not exclude interethnic variability of this biometric measure. © 2024 International Society of Ultrasound in Obstetrics and Gynecology.

Validation of a built-in software in automatically reconstructing the tomographic images of the levator ani muscle

INTRODUCTION AND HYPOTHESIS

Transperineal ultrasound (TPUS) is an effective tool for evaluating the integrity of the levator ani muscle (LAM). Several operating steps are required to obtain the standard multi-slice image of the LAM, which is experience dependent and time consuming. This study was aimed at evaluating the feasibility and reproducibility of the built-in software, Smart-pelvic™, in reconstructing standard tomographic images of LAM from 3D/4D TPUS volumes.

METHODS

This study was conducted at a tertiary teaching hospital, enrolling women who underwent TPUS. Tomographic images of the LAM were automatically reconstructed by Smart-pelvicTM and rated by two experienced observers as standard or nonstandard. The anteroposterior diameter (APD) of the levator hiatus was also measured on the mid-sagittal plane of the automatically and manually reconstructed images. The APD measurements of each approach were compared using Bland-Altman plots, and interclass correlation coefficient (ICC) was used to evaluate intra- and inter-observer reproducibility. Meanwhile, the time taken for the reconstruction process of both methods was also recorded.

RESULTS

The ultrasound volume of a total of 104 patients were included in this study. Using Smart-pelvicTM, the overall success rate of the tomographic image reconstruction was 98%. Regarding measurements of APD, the ICC between the automatic and manual reconstruction methods was 0.99 (0.98, 0.99). The average time taken for reconstruction per case was 2.65 ± 0.52 s and 22.08 ± 3.45 s, respectively.

CONCLUSIONS

Using Smart-pelvicTM to reconstruct tomographic images of LAM is feasible, and it can promote TPUS by reducing operator dependence and improving examination efficiency in a clinical setting.

Diagnosis of maternal birth trauma by pelvic floor ultrasound

BRIEF SUMMARY

Maternal somatic birth trauma due to vaginal delivery is more common than generally assumed and an important cause of future morbidity. Maternal birth trauma may involve both psychological and somatic morbidity, some of it long-term and permanent. Somatic birth trauma is now understood to encompass not just episiotomy, perineal tears and obstetric anal sphincter injuries (OASI), but also trauma to the levator ani muscle, termed 'avulsion'. This review will focus on recent developments in the imaging diagnosis of maternal birth trauma, discuss the most important risk factors and strategies for primary and secondary prevention. Translabial and exo-anal ultrasound allow the assessment of maternal birth trauma in routine clinical practice and enable the use of levator avulsion and anal sphincter trauma as key performance indicators of maternity services. This is likely to lead to a greater awareness of maternal birth trauma amongst maternity caregivers and improved outcomes for patients, not the least due to an increasing emphasis on patient autonomy and informed consent in antenatal and intrapartum care.

Can Clinical Postpartum Muscle Assessment Help Predict the Severity of Postpartum Pelvic Girdle Pain? A Prospective Cohort Study

OBJECTIVE

The purpose of this study was to evaluate whether the clinical assessment of pelvic floor muscles and the diastasis recti abdominis could predict the severity of pelvic girdle pain during the first year postpartum.

METHODS

Between 2018 and 2020, 504 women were recruited to this prospective longitudinal cohort study. At 2 to 3 months postpartum, their pelvic floor muscles and diastasis recti abdominis were assessed using vaginal palpation, observation, and caliper measurement. The participants completed the Pelvic Girdle Questionnaire (PGQ) at 2 to 3, 6, 9, and 12 months postpartum. Mixed-effect models were used to determine how the results of pelvic floor muscle and diastasis recti abdominis assessments predicted the PGQ score. A sub-analysis for middle to high PGQ scores was conducted.

RESULTS

Maximal voluntary pelvic floor muscle contractions ≥3 (Modified Oxford Scale, scored from 0 to 5) predicted a decreased PGQ score (β = -3.13 [95% CI = -5.77 to -0.48]) at 2 to 3 months postpartum, with a higher prediction of a middle to high PGQ score (β = -6.39). Diastasis recti abdominis width did not have any significant correlation with the PGQ score. A sub-analysis showed that a diastasis recti abdominis width ≥35 mm predicted an increased PGQ score (β = 5.38 [95% CI = 1.21 to 9.55]) in women with pelvic girdle pain.

CONCLUSION

The distinction between weak and strong maximal voluntary pelvic floor muscle contractions is an important clinical assessment in women with postpartum pelvic girdle pain. The exact diastasis recti abdominis width, measured in millimeters, showed no clinical relevance. However, a diastasis recti abdominis width ≥35 mm was associated with a higher PGQ score, and further research about this cutoff point in relation to pain is needed.

IMPACT

This study highlights the importance of clinical assessment of pelvic floor muscles in patients with postpartum pelvic girdle pain. A better understanding of the role of this muscle group will enable more effective physical therapist treatment of pelvic girdle pain.

All or nothing? A second look at partial levator avulsion

OBJECTIVE

To define associations between partial levator trauma and symptoms and signs of pelvic organ prolapse (POP).

METHODS

This was a retrospective study of 3484 women attending a tertiary urogynecology unit for symptoms of pelvic floor dysfunction between January 2012 and February 2020. All women underwent a standardized interview, clinical pelvic organ prolapse quantification (POP-Q) examination and tomographic ultrasound imaging of the pelvic floor. Women with full levator avulsion were excluded from analysis. Partial levator avulsion was quantified using the tomographic trauma score (TTS), in which slices 3-8 are scored bilaterally for abnormal insertions. Binomial multiple logistic regression was analyzed independently for the outcome variables prolapse symptoms, symptom bother and objective prolapse on clinical examination and imaging, with age and body mass index as covariates. Two continuous outcome variables, prolapse bother score and hiatal area on Valsalva, were analyzed using multiple linear regression.

RESULTS

Of the 3484 women, ultrasound data were missing or incomplete in 164 due to lack of equipment, clerical error and/or inadequate image quality. Full levator avulsion was diagnosed in 807 women, leaving 2513 for analysis. TTS ranged from 0-10, with a median of 0. Partial trauma (TTS > 0) was observed in 667/2513 (26.5%) women. All subjective and objective measures of POP were associated significantly with TTS, most strongly for cystocele. Associations were broadly linear and similar for all slice locations but disappeared after accounting for hiatal area on Valsalva.

CONCLUSION

Partial avulsion is associated with POP and prolapse symptoms. This association was strongest for cystocele, both on POP-Q and ultrasound imaging. The effect of partial avulsion on POP and prolapse symptoms is explained fully by its effect on hiatal area. © 2022 International Society of Ultrasound in Obstetrics and Gynecology.

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

OBJECTIVE

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.

METHODS

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.

RESULTS

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.

CONCLUSIONS

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.

Mechanisms of pelvic floor muscle training for managing urinary incontinence in women: a scoping review

BACKGROUND

Pelvic floor muscle training is recommended as first line treatment for urinary incontinence in women based on three proposed theorized mechanisms: 'Enhanced Pelvic Floor Muscle Strength,' 'Maximized Awareness of Timing,' and 'Strengthened Core Muscles'. The purpose of this scoping review was to systematically map evidence for and against theorized mechanisms through which pelvic floor muscle training interventions work to reduce urinary incontinence in women.

METHODS

The scoping review is based upon a comprehensive search of relevant literature published from 1990 to 2020 in PubMed, CINAHL, PsycINFO, ClinialTrials.gov, reference lists from review articles, and hand searches of articles by known researchers in the field. We included English-language, peer-reviewed articles on pelvic floor muscle training as an intervention for adult women if they provided empirical evidence to testing the theorized intervention mechanisms. Two independent reviewers screened articles for inclusion and extracted data to describe details of each study (author, year, country, design, sampling), measures of pelvic floor muscle strength and urinary incontinence, statistical analysis of linkage between changes in the measures, and pelvic floor muscle training regimens. Data were summarized to facilitate the integration of diverse evidence to draw conclusions on supporting or refuting the three proposed theorized mechanisms for managing urinary incontinence in women.

RESULTS

Of the 278 articles identified with the search, 13 (4.7%) met inclusion criteria. There was weak to no evidence for the mechanism of enhanced pelvic floor muscle strength, equivocal support for maximized awareness of timing, and no evidence for strengthened core muscles.

CONCLUSIONS

This review revealed extremely limited data supporting the proposed theorized mechanisms underlying pelvic floor muscle training programs to manage urinary incontinence in women. Such evidence is needed to help women and clinicians understand how, why and when a woman benefits from pelvic floor muscle training. Future studies should specifically state and report statistical analysis that relates the theorized mechanisms to the training outcomes observed.

Promotion on labor process and relief of the low back pain by relaxing pelvic muscle with Shangliao (BL 31) point injection in women using epidural analgesia during labor: A randomized, controlled, clinical trial

BACKGROUND

The purpose of this study was to explore the effects of combing Shangliao point injection with epidural analgesia on labor pain and birth process in women with low back pain and the possible mechanisms.

METHODS

93 consecutive women were randomized to receive either Shangliao point injection combined with epidural analgesia or epidural analgesia. Another 14 women were recruited to explore the mechanisms and the transperineal ultrasound was performed accordingly.

RESULTS

The main result duration from epidural analgesia to baby delivery was significantly shorter in epidural analgesia and saline injection group than that in epidural analgesia group 307.0 (175.0-445.0) min VS 369.0 (254.0-563.0) min (P = 0.02). The verbal numerical rate scaling score in low back during the first contraction was significantly decreased 5.0 (4.0-7.0) after Shangliao point injections (P < 0.001). The consumption of ropivacaine per hour was significantly less in epidural analgesia and saline injection group than in epidural analgesia group (-0.4 mg, 95%CI: -0.1 to -1.8; P = 0.03). The angle of progression and anteroposterior diameter of the levator hiatus at rest and during valsalva were significantly increased after shangliao point injection (7.10°, 95%CI, 1.50~12.70; P = 0.02); (9.10°, 95%CI, 3.60~14.58; P < 0.01); (0.27 cm, 95%CI, 0.03~0.51; P = 0.03); (0.30 cm, 95%CI, 0.13~0.48; P < 0.01).

CONCLUSIONS

Shangliao point injection could shorten the time to baby delivery and rapidly relieve low back pain in addition to epidural analgesia, that may attribute to its function of relaxing the pelvic floor muscles and promote fetal head progress.

Ultrasound imaging of maternal birth trauma

INTRODUCTION AND HYPOTHESIS

The term 'maternal birth trauma' has undergone substantial changes in meaning over the last 2 decades. Leaving aside psychological morbidity, somatic trauma is now understood to encompass not just episiotomy, perineal tears and obstetric anal sphincter injuries (OASI), but also trauma to the levator ani muscle. This review covers diagnosis of maternal birth trauma by translabial ultrasound imaging.

METHODS

Narrative review.

RESULTS

Tomographic imaging of pelvic structures with the help of 4D ultrasound, used since 2007, has allowed international standardization and seems to be highly reproducible and valid for the diagnosis of OASI and levator avulsion.

CONCLUSIONS

Translabial and exo-anal ultrasound allows the assessment of maternal birth trauma in routine clinical practice and the utilization of avulsion and sphincter trauma as key performance indicators of maternity services. It is hoped that this will lead to a greater awareness of maternal birth trauma among maternity caregivers and improved outcomes for patients, both in the short term and in the decades to come.

Pelvic floor ultrasound finds after episiotomy and severe perineal tear: systematic review and meta-analysis

AIM

Vaginal delivery is a well-known risk factor for pelvic floor muscle (PFM) injuries, mainly when associated to prolonged labor, instrumental birth and perineal trauma such as episiotomy and perineal tears. The purpose of this meta-analysis was to test the hypothesis that episiotomy and severe perineal tear may increase the risk of pelvic floor damage.

METHODS

We performed a systematic literature search through electronic databases including MEDLINE via PubMed, LILACS via BVS, Embase via Elsevier and Cochrane Library up to January 2019. We included articles that reported as outcome one or more morphological aspects of the PFM evaluated by ultrasonography in primiparous women three to 24 months postpartum. This review is registered in the PROSPERO database (registration number: CRD42017075750).

RESULTS

the final selection was composed of 18 articles for the systematic review, and 10 for the meta-analysis. Women with levator ani muscle (LAM) avulsion were 1.77 times more likely to have undergone episiotomy (OR = 1.77, CI 95% 1.25-2.51, five trials), 4.31 times more likely to have severe perineal tear (OR = 4.31, CI 95% 2.34-7.91, two trials). Women with defects in the anal sphincters were 2.82 times more likely to have suffered severe perineal tear (OR = 2.82, 95% CI 1.71-4.67, three trials).

CONCLUSIONS

Both episiotomy and severe perineal tear are risk factors for LAM avulsion and anal sphincter injury, and this can be useful for identifying women who are at greater risk of developing PFM dysfunctions.

Value of high-frequency two-dimensional ultrasound on evaluating puborectalis muscle

PURPOSE

To explore the value of high-frequency two-dimensional (2D) ultrasound on demonstrating the morphology of puborectalis muscle and detect muscle avulsion.

METHODS

High-frequency 2D ultrasound and tomographic ultrasound image (TUI) were peformed to demonstrate puborectalis muscle and detect muscle avulsion respectively among 158 women with or without significant pelvic organ prolapse (POP) (POP quantification grade 2 or higher). Mean values were compared using student's t test between women with or without avulsion defects. We performed Cohen's Kappa analysis to examine the test agreement between high-frequency 2D ultrasound and TUI mode. Pearson correlation analysis was performed to explore the relationship between the thickness of puborectalis muscle and the measurements of levator-urethra gap (LUG).

RESULTS

The result of high-frequency 2D ultrasound in detecting muscle avulsion agreed well with TUI mode (Kappa 0.88, P < 0.05). Women with muscle avulsion had thinner muscles and larger LUG measurements than those with normal muscle insertion (P < 0.05). Pearson correlation analysis revealed the negative relationship between the thickness of puborectalis muscle and LUG measurements (r = - 0.73).

CONCLUSION

The study confirmed that it was feasible to observe the morphology of puborectalis muscle and detect muscle avulsion by high-frequency 2D ultrasound.

Levator ani muscle coactivation at term is associated with longer second stage of labor in nulliparous women

OBJECTIVE

To assess the effect of levator ani muscle (LAM) coactivation at term on outcome of labor in nulliparous women.

METHODS

This was a prospective study of 284 low-risk nulliparous women with a singleton pregnancy at term recruited before the onset of labor. The anteroposterior diameter of the levator hiatus was measured in each woman on transperineal ultrasound at rest, on maximum pelvic floor muscle contraction and on maximum Valsalva maneuver before and after visual feedback. LAM coactivation was defined as a reduction in the anteroposterior diameter of the levator hiatus on maximum Valsalva maneuver in comparison with that at rest. The association of pelvic hiatal diameter values and LAM coactivation with mode of delivery and duration of labor was assessed.

RESULTS

No significant difference was found between women who underwent Cesarean delivery and those who had a vaginal delivery with regard to the anteroposterior diameter of the levator hiatus at rest, on pelvic floor muscle contraction and on Valsalva maneuver. Longer second stage of labor was associated with shorter anteroposterior diameter of the levator hiatus on all assessments, but in particular at rest and on Valsalva both before and after visual feedback. LAM coactivation was found in 89 (31.3%) and 75 (26.4%) women before and after visual feedback, respectively. Post visual feedback, women with LAM coactivation had a significantly longer second stage of labor than did those without LAM coactivation (83 ± 63 vs 63 ± 42 min; P = 0.006). On Cox regression analysis, LAM coactivation post visual feedback was an independent predictor of longer second stage of labor (adjusted hazard ratio, 1.499 (95% CI, 1.076-2.087); P = 0.017).

CONCLUSION

LAM coactivation in nulliparous women at term is associated with a longer second stage of labor. Copyright © 2018 ISUOG. Published by John Wiley & Sons Ltd.

Contraction of the levator ani muscle during Valsalva maneuver (coactivation) is associated with a longer active second stage of labor in nulliparous women undergoing induction of labor

BACKGROUND

The Valsalva maneuver is normally accompanied by relaxation of the levator ani muscle, which stretches around the presenting part, but in some women the maneuver is accompanied by levator ani muscle contraction, which is referred to as levator ani muscle coactivation. The effect of such coactivation on labor outcome in women undergoing induction of labor has not been previously assessed.

OBJECTIVE

The aim of the study was to assess the effect of levator ani muscle coactivation on labor outcome, in particular on the duration of the second and active second stage of labor, in nulliparous women undergoing induction of labor.

STUDY DESIGN

Transperineal ultrasound was used to measure the anteroposterior diameter of the levator hiatus, both at rest and at maximum Valsalva maneuver, in a group of nulliparous women undergoing induction of labor in 2 tertiary-level university hospitals. The correlation between anteroposterior diameter of the levator hiatus values and levator ani muscle coactivation with the mode of delivery and various labor durations was assessed.

RESULTS

In total, 138 women were included in the analysis. Larger anteroposterior diameter of the levator hiatus at Valsalva was associated with a shorter second stage (r = -0.230, P = .021) and active second stage (r = -0.338, P = .001) of labor. Women with levator ani muscle coactivation had a significantly longer active second stage duration (60 ± 56 vs 28 ± 16 minutes, P < .001). Cox regression analysis, adjusted for maternal age and epidural analgesia, demonstrated an independent significant correlation between levator ani muscle coactivation and a longer active second stage of labor (hazard ratio, 2.085; 95% confidence interval, 1.158-3.752; P = .014). There was no significant difference between women who underwent operative delivery (n = 46) when compared with the spontaneous vaginal delivery group (n = 92) as regards anteroposterior diameter of the levator hiatus at rest and at Valsalva maneuver, nor in the prevalence of levator ani muscle coactivation (10/46 vs 15/92; P = .49).

CONCLUSION

Levator ani coactivation is associated with a longer active second stage of labor.

Fundal pressure in second stage of labor (Kristeller maneuver) is associated with increased risk of levator ani muscle avulsion

OBJECTIVE

To investigate the association between application of fundal pressure during the second stage of labor (Kristeller maneuver) and the risk of levator ani muscle (LAM) injury.

METHODS

This was a prospective case-control study of women recruited immediately after their first vaginal delivery in our university hospital between March 2014 and September 2016. Women who underwent the Kristeller maneuver were recruited as cases. For each case, a control (no Kristeller) was recruited matched for body mass index, use of epidural analgesia, duration of second stage of labor and birth weight. All women were invited to undergo four-dimensional (4D) transperineal ultrasound (TPU) 3-6 months postpartum. The main outcome measure was the presence of LAM avulsion on 4D-TPU. TPU results were compared between cases and controls. Multivariate logistic regression analysis was performed to identify independent risk factors for LAM avulsion.

RESULTS

During the study period, 134 women in the Kristeller maneuver group and 128 women in the control group underwent TPU assessment. Women who underwent the Kristeller maneuver had a higher prevalence of LAM avulsion than did controls (38/134 (28.4%) vs 18/128 (14.1%); P = 0.005). In addition, women in the Kristeller-maneuver group had a larger hiatal area on maximum Valsalva maneuver and a greater increase in hiatal area from rest to maximum Valsalva. On multivariate logistic regression analysis, use of the Kristeller maneuver was the only independent factor associated with LAM avulsion (odds ratio, 2.5 (95% CI, 1.29-4.51)).

CONCLUSION

The Kristeller maneuver is associated with an increased risk of LAM avulsion when applied in women during their first vaginal delivery. This should be taken into account when deciding to use fundal pressure to accelerate the second stage of labor and when counseling women following childbirth. Copyright © 2018 ISUOG. Published by John Wiley & Sons Ltd.

Association between pelvic organ prolapse types and levator-urethra gap as measured by 3D transperineal ultrasound

OBJECTIVES

To evaluate the association between pelvic organ prolapse (POP) types and levator-urethra gap (LUG) as measured by 3-dimensional transperineal tomographic ultrasound.

METHODS

A retrospective study was carried out on 98 women with symptomatic POP. Three-dimensional transperineal tomographic ultrasound images and POP quantification coordinates were reviewed. Each vaginal compartment was staged for the degree of prolapse, and total number of involved compartments identified. LUG was measured on 3-dimensional tomographic sonograms as the distance between the center of the urethra and the levator insertion bilaterally. Based on prior studies, an abnormal LUG of 25 mm or greater indicated levator avulsion. The LUG and the presence or absence of unilateral/bilateral avulsions was analyzed with reference to the clinical diagnosis of prolapse (single versus multicompartment, and mild [stage II] versus severe [stage III-IV]). Generalized logit models were used to evaluate the association between avulsion and prolapse type and stage.

RESULTS

The LUG was substantially larger in women with multicompartment compared to single-compartment POP (28.9 ± 4.1 mm versus 22.7 ± 4.1 mm, P < .01). Similarly, LUG was substantially larger in women with severe (stage III-IV) compared to mild (stage II) POP (28.8 ± 4.7 mm versus 23.3 ± 4.5 mm, P < .01). Women with severe prolapse were 32 times more likely than women with mild prolapse to have bilateral levator avulsion. Those with POP involving all 3 vaginal compartments were 76 times more likely than single-compartment POP to have bilateral levator avulsions.

CONCLUSIONS

Bilateral levator ani avulsion as diagnosed by LUG measurements of 25 mm or greater at rest is associated with multicompartment, severe prolapse.

Translabial US and Dynamic MR Imaging of the Pelvic Floor: Normal Anatomy and Dysfunction

Pelvic floor dysfunction (PFD) is a common condition that typically affects women older than 50 years and decreases the quality of life. Weakening of support structures can involve all three pelvic compartments and cause a combination of symptoms, including constipation, urinary and fecal incontinence, obstructed defecation, pelvic pain, perineal bulging, and sexual dysfunction. The causes of PFD are complex and multifactorial; however, vaginal delivery is considered a major predisposing factor. Physical examination alone is limited in the evaluation of PFD; it frequently leads to an underestimation of the involved compartments. Imaging has an important role in the clinical evaluation, yielding invaluable information for patient counseling and surgical planning. Three- and four-dimensional translabial ultrasonography (US) is a relatively new imaging modality with high accuracy in the evaluation of PFD such as urinary incontinence, pelvic organ prolapse, and puborectalis avulsion. Evaluation of mesh implants is another important indication for this modality. Dynamic magnetic resonance (MR) imaging of the pelvic floor is a well-established modality for pelvic floor evaluation, with high-resolution images yielding detailed anatomic information and dynamic sequences yielding functional data. Specific protocols and dedicated image interpretation are required with both of these imaging methods. In this article, the authors review the normal anatomy of the female pelvic floor by using a practical approach, discuss the roles of translabial US and MR imaging in the investigation of PFD, describe the most appropriate imaging protocols, and illustrate the most common imaging findings of PFD in the anterior, middle, and posterior compartments of the pelvis. Online supplemental material is available for this article. ^©RSNA, 2018.

Ultrasound in the assessment of pelvic organ prolapse

Imaging is increasingly being used in urogynaecology. Because of low cost and universal availability, ultrasound (US) is the most commonly used diagnostic modality, which allows the observation of manoeuvres such as Valsalva and pelvic floor muscle contraction in real time. The ability to see beyond surface anatomy is particularly important in the posterior compartment and in obstructed defecation where this method may replace defecation proctography. Imaging is especially useful in the form of 3D/4D multiplanar and tomographic translabial US, as these modalities give access to the axial plane and the levator ani. This allows assessment of both avulsion, i.e. major maternal birth trauma, and hiatal overdistension, i.e. ballooning. Both are major risk factors for both prolapse and prolapse recurrence. This review will outline current clinical utility, introduce recent research in the respective field and provide an overview of likely future utility of imaging in the investigation of pelvic organ prolapse.

Association between pelvic floor dysfunction, and clinical and ultrasonographic evaluation in primiparous women: a cross-sectional study

PURPOSE

Disorders related to pelvic floor include urinary incontinence (UI), anal incontinence, pelvic organ prolapse, sexual dysfunction and pelvic pain. Because pelvic floor dysfunctions (PFD) can be diagnosed clinically, imaging techniques serve as auxiliary tools for establishing an accurate diagnosis. The objective is to evaluate the PFD in primiparous women after vaginal delivery and the association between clinical examination and three-dimensional ultrasonography (3DUS).

METHODS

A cross-sectional study was conducted in a in tertiary maternity. All primiparous women with vaginal deliveries that occurred between January 2013 and December 2015 were invited. Women who attended the invitation underwent detailed anamnesis, questionnaire application, physical examination and endovaginal and endoanal 3DUS. Crude and adjusted predictor factors for PFD were analyzed.

RESULTS

Fifty women were evaluated. Sexual dysfunction was the most prevalent PFD (64.6%). When associated with clinical features and PFD, oxytocin use increased by approximately four times the odds of UI (crude OR 4.182, 95% CI 1.149-15.219). During the multivariate analysis, the odds of UI were increased in forceps use by approximately 11 times (adjusted OR 11.552, 95% CI 11.155-115.577). When the clinical and obstetrical predictors for PFD were associated with 3DUS, forceps increased the odds of lesion of the pubovisceral muscle and anal sphincter diagnosed by 3DUS by sixfold (crude OR 6.000, 95% CI 1.172-30.725), and in multivariate analysis forceps again increased the odds of injury by approximately 7 times (adjusted OR 7.778, 95% CI 1.380-43.846).

CONCLUSION

Sexual dysfunction was the most frequent PFD. The use of forceps in primiparous women was associated with a greater chance of UI and pelvic floor muscle damage diagnosed by 3DUS.

Can We Evaluate Hiatal Ballooning by Measuring the Anteroposterior Diameter With 2-Dimensional Translabial Ultrasonography?

OBJECTIVES

To analyze the association between the anteroposterior hiatal diameter and pelvic organ prolapse and to determine whether 2-dimensional translabial ultrasonography can evaluate hiatal ballooning by measuring the anteroposterior diameter.

METHODS

This study was a retrospective analysis of 312 women seen for lower urinary tract symptoms or pelvic organ prolapse between December 2014 and July 2016. All women had an International Continence Society (ICS) Pelvic Organ Prolapse Quantification (POP-Q) system examination and 4-dimensional translabial ultrasonography. The anteroposterior hiatal diameter was measured in the midsagittal plane, and the hiatal area was measured in the minimal axial plane during the maximal Valsalva maneuver.

RESULTS

Valid data from 294 patients were analyzed. International Continence Society POP-Q stage 0 was found in 121 women, stage 1 in 49, stage 2 in 78, stage 3 in 42, and stage 4 in 4. The anteroposterior diameter had an excellent linear correlation (r = 0.814; P < .001) with the hiatal area during the Valsalva maneuver and was strongly related to ICS POP-Q stages (P < .01). A receiver operating characteristic curve analysis proposed a cutoff of 6.0 cm for the anteroposterior diameter against ICS POP-Q stage 2 and higher (sensitivity, 73%; specificity, 52%) and prolapse symptoms (sensitivity, 74%; specificity, 64%).

CONCLUSIONS

The anteroposterior hiatal diameter, which represents hiatal distensibility in the midsagittal plane, can be used to evaluate hiatal ballooning. "Mild" ballooning was defined as an anteroposterior diameter measurement of 6.0 to less than 6.5 cm, "moderate" ballooning as 6.5 to less than 7.0 cm, and "marked" ballooning as 7.0 cm or greater.

Modern Theories of Pelvic Floor Support : A Topical Review of Modern Studies on Structural and Functional Pelvic Floor Support from Medical Imaging, Computational Modeling, and Electromyographic Perspectives

PURPOSE OF REVIEW

Weakened pelvic floor support is believed to be the main cause of various pelvic floor disorders. Modern theories of pelvic floor support stress on the structural and functional integrity of multiple structures and their interplay to maintain normal pelvic floor functions. Connective tissues provide passive pelvic floor support while pelvic floor muscles provide active support through voluntary contraction. Advanced modern medical technologies allow us to comprehensively and thoroughly evaluate the interaction of supporting structures and assess both active and passive support functions. The pathophysiology of various pelvic floor disorders associated with pelvic floor weakness is now under scrutiny from the combination of (1) morphological, (2) dynamic (through computational modeling), and (3) neurophysiological perspectives. This topical review aims to update newly emerged studies assessing pelvic floor support function among these three categories.

RECENT FINDINGS

A literature search was performed with emphasis on (1) medical imaging studies that assess pelvic floor muscle architecture, (2) subject-specific computational modeling studies that address new topics such as modeling muscle contractions, and (3) pelvic floor neurophysiology studies that report novel devices or findings such as high-density surface electromyography techniques. We found that recent computational modeling studies are featured with more realistic soft tissue constitutive models (e.g., active muscle contraction) as well as an increasing interest in simulating surgical interventions (e.g., artificial sphincter). Diffusion tensor imaging provides a useful non-invasive tool to characterize pelvic floor muscles at the microstructural level, which can be potentially used to improve the accuracy of the simulation of muscle contraction. Studies using high-density surface electromyography anal and vaginal probes on large patient cohorts have been recently reported. Influences of vaginal delivery on the distribution of innervation zones of pelvic floor muscles are clarified, providing useful guidance for a better protection of women during delivery. We are now in a period of transition to advanced diagnostic and predictive pelvic floor medicine. Our findings highlight the application of diffusion tensor imaging, computational models with consideration of active pelvic floor muscle contraction, high-density surface electromyography, and their potential integration, as tools to push the boundary of our knowledge in pelvic floor support and better shape current clinical practice.

Maternal birth trauma: why should it matter to urogynaecologists?

PURPOSE OF REVIEW

There is increasing awareness of the importance of intrapartum events for future pelvic floor morbidity in women. In this review, we summarize recent evidence and potential consequences for clinical practice.

RECENT FINDINGS

Both epidemiological evidence and data from perinatal imaging studies have greatly improved our understanding of the link between childbirth and later morbidity. The main consequences of traumatic childbirth are pelvic organ prolapse (POP) and anal incontinence. In both instances the primary etiological pathways have been identified: levator trauma in the case of POP and anal sphincter tears in the case of anal incontinence. As most such trauma is occult, imaging is required for diagnosis.

SUMMARY

Childbirth-related major maternal trauma is much more common than generally assumed, and it is the primary etiological factor in POP and anal incontinence. Both sphincter and levator trauma can now be identified on imaging. This is crucial not only for clinical care and audit, but also for research. Postnatally diagnosed trauma can serve as intermediate outcome measure in intervention trials, opening up multiple opportunities for clinical research aimed at primary and secondary prevention.

[Assessment before surgical treatment for pelvic organ prolapse: Clinical practice guidelines]

INTRODUCTION

The issue addressed in this chapter of recommendations is: What is the clinical and para-clinical assessment to achieve in women with genital prolapse and for whom surgical treatment has been decided. What are the clinical elements of the examination that must be taken into account as a risk factor of failure or relapse after surgery, in order to anticipate and evaluate possible surgical difficulties, and to move towards a preferred surgical technique?

MATERIAL AND METHODS

This work is based on a systematic review of the literature (PubMed, Medline, Cochrane Library, Cochrane Database of Systemactic Reviews, EMBASE) for meta-analyzes, randomized trials, registries, literature reviews, controlled studies and major not controlled studies, published on the subject. Its implementation has followed the methodology of the HAS on the recommendations for clinical practice, with a scientific argument (with the level of evidence, NP) and a recommendation grade (A, B, C, and professional agreement [AP]).

RESULTS

It suits first of all to describe prolapse, by clinical examination, helped, if needed, by a supplement of imagery if clinical examination data are insufficient or in case of discrepancy between the functional signs and clinical anomalies found, or in case of doubt in associated pathology. It suits to look relapse risk factors (high grade prolapse) and postoperative complications risk factors (risk factors for prothetic exposure, surgical approach difficulties, pelvic pain syndrome with hypersensitivity) to inform the patient and guide the therapeutic choice. Urinary functional disorders associated with prolapse (urinary incontinence, overactive bladder, dysuria, urinary tract infection, upper urinary tract impact) will be search and evaluated by interview and clinical examination and by a flowmeter with measurement of the post voiding residue, a urinalysis, and renal-bladder ultrasound. In the presence of voiding disorders, it is appropriate to do their clinical and urodynamic evaluation. In the absence of any spontaneous or hidden urinary sign, there is so far no reason to recommend systematically urodynamic assessment. Anorectal symptoms associated with prolapse (irritable bowel syndrome, obstruction of defecation, fecal incontinence) should be search and evaluated. Before prolapse surgery, it is essential not to ignore gynecologic pathology.

CONCLUSION

Before proposing a surgical cure of genital prolapse of women, it suits to achieve a clinical and paraclinical assessment to describe prolapse (anatomical structures involved, grade), to look for recurrence, difficulties approach and postoperative complications risk factors, and to appreciate the impact or the symptoms associated with prolapse (urinary, anorectal, gynecological, pelvic-perineal pain) to guide their evaluation and their treatment. © 2016 Published by Elsevier Masson SAS.

Is it necessary to diagnose levator avulsion on pelvic floor muscle contraction?

OBJECTIVE

Avulsion of the levator ani muscle commonly occurs at vaginal birth. This condition is usually diagnosed by translabial ultrasound (TLUS) during pelvic floor muscle contraction (PFMC). Some patients are unable to achieve a satisfactory PFMC and in these cases avulsion is assessed at rest. The aim of this study was to validate the diagnosis of levator avulsion by means of TLUS at rest.

METHODS

This was a retrospective study of 233 women seen at a tertiary urogynecological center. All women underwent four-dimensional TLUS in the supine position and after voiding. Volumes were obtained on maximal PFMC and at rest. Analysis of the volumes was performed with the observer blinded against all clinical data. Avulsion was defined as an abnormal levator ani muscle insertion that was visible in at least three consecutive axial plane slices, at and above the level of minimal hiatal dimensions, at 2.5-mm intervals. We examined the correlation between both assessment methods using Cohen's kappa coefficient and tested the association of each method with female pelvic organ prolapse on clinical examination, organ descent on ultrasound and hiatal ballooning.

RESULTS

In total, datasets from 202 women were available for analysis. The correlation between a diagnosis of avulsion in volumes obtained at rest and those on PFMC was moderate, with a kappa value of 0.583 (95% CI, 0.484-0.683). Agreement for defects visualized on single slices was moderate, with a kappa value of 0.556 (95% CI, 0.520-0.591). When avulsion diagnoses at rest and on PFMC were tested against symptoms of prolapse, and prolapse on clinical examination and on ultrasound, neither of the two methods was superior.

CONCLUSION

Although tomographic ultrasound imaging during PFMC enhances tissue discrimination, this may not translate to superior diagnostic performance. Hence, volumes obtained at rest may be used in women unable to contract their pelvic floor. The diagnosis of levator avulsion by tomographic pelvic floor ultrasound is equally valid when performed at rest or on PFMC. Copyright © 2015 ISUOG. Published by John Wiley & Sons Ltd.

Ultrasound Imaging of the Pelvic Floor

This article discusses the background and appraisal of endoluminal ultrasound of the pelvic floor. It provides a detailed anatomic assessment of the muscles and surrounding organs of the pelvic floor. Different anatomic variability and pathology, such as prolapse, fecal incontinence, urinary incontinence, vaginal wall cysts, synthetic implanted material, and pelvic pain, are easily assessed with endoluminal vaginal ultrasound. With pelvic organ prolapse in particular, not only is the prolapse itself seen but the underlying cause related to the anatomic and functional abnormalities of the pelvic floor muscle structures are also visualized.

Toward normal birth-but at what cost?

The rate of cesarean delivery has become an important health care issue, and has attracted the attention of governments, professional organizations, health care administrators, clinicians, and patients. This has resulted in the generation of guidelines, clinical recommendations, and other documents aimed at increasing the likelihood of vaginal delivery. Sometimes, these recommendations are formulated with limited input from clinicians. In some countries, such as the United Kingdom, external pressure exerted on clinicians to reduce the rate of cesarean delivery has been the subject of public debate, and has led to unintended consequences, including an increase in medicolegal tensions. In the United States and Australia, recent recommendations generated by professional bodies have advocated that clinicians should change practice to reduce the rate of cesarean delivery. We do not summarize the risks and benefits of cesarean birth in different clinical situations, which have been the subject of numerous reviews. Rather, we try to examine the potential implications of such policies in light of recent observations made in maternity units, judicial decisions, and clinical research. The emphasis is on maternal morbidity and patient autonomy. This may include the negative consequences of increasingly risky attempts at vaginal birth after cesarean delivery such as uterine rupture, higher rates of pelvic floor and anal sphincter trauma due to rising forceps rates, and a bias against elective cesarean delivery on maternal request.

Does the prevalence of levator ani muscle avulsion differ when assessed using tomographic ultrasound imaging at rest vs on maximum pelvic floor muscle contraction?

OBJECTIVE

It has been suggested that transperineal ultrasound images obtained during maximum pelvic floor muscle contraction improve the diagnosis of levator ani muscle (LAM) avulsion by comparison with those obtained at rest. The objective of this study was to establish, using transperineal tomographic ultrasound imaging (TUI), the correlation between LAM avulsion diagnosed at rest and that on contraction.

METHODS

Primiparous women were examined 3 months postpartum by Pelvic Organ Prolapse Quantification (POP-Q) assessment and for LAM avulsion clinically by digital palpation and by transperineal TUI performed at rest and on pelvic floor muscle contraction. LAM avulsion was diagnosed on TUI when the three central slices were abnormal. A comparison was made between LAM avulsion diagnosed at rest and on maximum contraction. Two independent blinded investigators performed the analyses and a third investigator resolved discrepancies.

RESULTS

One hundred and ninety primiparae were analyzed providing 380 results for comparison, as right and left LAM were analyzed independently. LAM avulsion was found in 36 (9.5%) images obtained at rest and in 35 (9.2%) on contraction, revealing moderate correlation between the two (ICC, 0.58 (95% CI, 0.51-0.64)). Twenty-two cases of LAM avulsion were identified both at rest and on contraction. One woman had LAM avulsion on palpation, which was seen on TUI as LAM avulsion on contraction, but not at rest. More cases of anterior and posterior compartment prolapse were found in women with LAM avulsion diagnosed on contraction only compared to LAM avulsion observed at rest only (POP-Q assessment point Ba, -1.8 vs -2.5 (P = 0.075) and point Bp, -2.5 vs -2.8 (P = 0.072)).

CONCLUSIONS

Findings on transperineal TUI performed in women at rest and on contraction correlate reasonably well. However, given the trend towards an association with signs of pelvic floor dysfunction, diagnosis of LAM avulsion on contraction seems to be more reliable. Consistency in technique and interpretation should be maintained.

Translabial three-dimensional ultrasonography compared with magnetic resonance imaging in detecting levator ani defects

OBJECTIVE

To assess the diagnostic performance of translabial three-dimensional ultrasonography in detecting major levator ani defects in women with pelvic organ prolapse compared with magnetic resonance imaging (MRI) and to assess the interobserver agreement in detecting levator ani defects with translabial three-dimensional ultrasonography.

METHODS

In a multicenter cohort study, 140 women indicated for primary surgery of pelvic organ prolapse quantification stage II or more cystocele were included. Patients undergoing mesh surgery or concomitant stress incontinence surgery were excluded. All consenting patients underwent translabial three-dimensional ultrasonography and MRI of the pelvic floor before surgery. Two observers (out of a pool of four observers) assessed translabial three-dimensional ultrasound images; two other observers (out a pool of five observers) assessed MRIs for levator ani muscle damage. In case of disagreement, the images were discussed in a consensus meeting.

RESULTS

Of the 135 scans, 45 major levator ani defects were detected on ultrasonogram (33.3%) and 32 were confirmed at MRI (23.7%). Of the 41 major levator ani defects detected on MRI, nine were missed at translabial three-dimensional ultrasonogram. Sensitivity was 0.78 (32 of 41) (95% confidence interval [CI] 0.65-0.91) and specificity was 0.86 (81 of 94) (95% CI 0.79-0.93) in detecting major levator ani defects with translabial three-dimensional ultrasonography compared with MRI. There was good agreement scoring levator ani defects on translabial three-dimensional ultrasonography, with a κ of 0.67 (95% CI 0.58-0.76); agreement in recognizing major levator ani defects was moderate, with a κ of 0.53 (95% CI 0.37-0.69).

CONCLUSION

Translabial three-dimensional ultrasonography shows reasonable agreement with MRI in detecting major levator defects. Because of the moderate interobserver agreement, it will be difficult to implement ultrasonography in daily practice.

CLINICAL TRIAL REGISTRATION

Netherlands Trial Register, www.trialregister.nl, NTR2220.

Prevalence of Levator Ani Defects in Urogynecological Patients

Introduction: Defects of the levator ani muscle complex could represent a pathophysiological link between vaginal birth trauma and urogynecological symptoms many years later. The aim of our study was to determine the prevalence of levator ani muscle defects using 3D or 4D ultrasound and palpation in urogynecological patients. Material and Methods: Urogynecological patients were retrospectively investigated using 3D or 4D ultrasound. Clinical examination consisted of palpation and 3D or 4D imaging of the levator ani muscle. Results: A total of 319 women were included in the analysis. Mean age was 64.9 years, average parity was 2.1. Stress incontinence was present in 50.8 %, overactive bladder symptoms in 69.3 % and pelvic organ prolapse in 42.3 % of patients. A levator ani defect was found on ultrasound in 76 patients (23.8 %) and on palpation in 64 women (20.0 %). In the group of patients with pelvic organ prolapse, levator ani defects were found in 32.6 % of patients using ultrasound and in 26.7 % of patients using palpation. The odds ratio (OR) for levator ani defects in women with pelvic organ prolapse was 2.3 (95 % CI [CI: confidence interval]: 1.36-3.88], p = 0.002). Conclusion: In a cohort of urogynecological patients seen at a tertiary urogynecological unit, the prevalence of levator ani defects was significantly higher in women with pelvic organ prolapse compared to women with stress incontinence or urge symptoms.

Sonographic finding of postpartum levator ani muscle injury correlates with pelvic floor clinical examination

OBJECTIVES

Correlation of the sonographic finding of levator ani muscle (LAM) injuries with clinical examination in primiparous women following vaginal delivery has not been fully described. We aimed to examine the correlation of three-dimensional transperineal ultrasound (3D-TPS) finding of LAM defects with results of clinical examination of the pelvic floor, at intermediate follow-up.

METHODS

Subjects were primiparae 3-21 months following vaginal delivery, who had not become pregnant or delivered in the interim. On 3D-TPS, LAM trauma was diagnosed when discontinuity and distortion were visible in the most anteromedial part of the pubovisceral muscle in the coronal C-plane or rendered image. Clinical examination was performed by a physiotherapist who was blinded to the ultrasound results, and included palpation of the medial and lateral parts of the LAM mass, evaluation of tissue quality and whether there was any palpable gap. Muscle strength was evaluated using the modified Oxford scale.

RESULTS

Eighty-seven women were included, 19 (21.8%) of whom were found to have a sonographic LAM injury. Oxford score palpation parameter of asymmetric muscle mass or texture was significantly correlated with the finding of a LAM defect: of 68 women with normal 3D-TPS, 22 (32.4%) were found to have asymmetry of muscle mass or tissue quality on clinical examination vs 12 (63.2%) of 19 women with sonographic evidence of LAM injury (P = 0.016). Muscle strength and endurance parameters did not significantly correlate with the 3D-TPS findings.

CONCLUSION

Our findings suggest that persistent 3D-TPS LAM injury after primary vaginal delivery has clinical expression in changes in mass and texture of the LAM, as assessed by palpation.

Levator hematoma at the attachment zone as an early marker for levator ani muscle avulsion

OBJECTIVES

Childbirth causes overstretching of the levator ani muscle (LAM), predisposing to avulsion. LAM avulsion has not been evaluated early postpartum using endovaginal ultrasound (EVUS). The aim of this study was to evaluate the relationship between hematomas and LAM avulsion using EVUS and palpation early and late postpartum.

METHODS

Nulliparous women were studied prospectively at 36 weeks' gestation and within 4 days and 3 months postpartum. Palpation and high-frequency three-dimensional EVUS were performed. Two independent investigators reviewed the scans.

RESULTS

No antenatal LAM avulsions were found (n = 269). 114/199 (57.3%) women seen early postpartum agreed to examination. 27/114 (23.7%) had well delineated, hypoechoic areas consistent with hematomas (100% agreement), 26 following vaginal delivery, one following emergency Cesarean section. In total, 38 hematomas were found (11 bilateral, 16 unilateral). Hematomas away from the attachment zone of the LAM to the pubic bone (n = 22) resolved. Hematomas at the attachment zone (n = 16) manifested as pubococcygeus avulsions 3 months postpartum. In addition to these 16 avulsions, we found another 20 at 3 months postpartum. 13/20 were not scanned early postpartum and in seven no hematomas were seen, but avulsion was seen early postpartum. Overall, LAM avulsion was found in 23/191 (12.0%) women (13 bilateral, 10 unilateral) 3 months postpartum. Hematomas were significantly associated with episiotomy, instrumental delivery and increased hiatal measurements. Palpation was unreliable early postpartum as only seven avulsions were diagnosed.

CONCLUSION

Hematomas at the site of LAM attachment to the pubic bone always result in avulsion diagnosed 3 months postpartum. However, one third of avulsions are not preceded by a hematoma at the site of LAM attachment to the pubic bone.

Impact of levator trauma on pelvic floor muscle function

INTRODUCTION AND HYPOTHESIS

Levator trauma is common after vaginal delivery, either as macrotrauma, i.e., levator avulsion, or microtrauma, i.e., irreversible overdistension of the levator hiatus. The effect of microtrauma on muscle function is unknown. We tested the hypothesis that levator trauma is associated with reduced contractile function of the levator ani.

METHODS

Pregnant nulliparous women were recruited and seen before and after childbirth. All underwent an interview, a clinical examination including pelvic floor muscle (PFM) assessment using the Modified Oxford scale (MOS) [as an optional component] and translabial ultrasound. Sonographic and clinical parameters of PFM function were assessed before and after childbirth.

RESULTS

Out of 560 women, 446 returned at a median of 5 months after childbirth and 433 were suitable for analysis. There was a significant reduction in all measures of PFM function except for MOS. Change in MOS was associated with delivery mode [analysis of variance (ANOVA) P = 0.006). Forty-seven (15 %) vaginally parous women were diagnosed with levator avulsion, which was associated with a reduction in PFM contractility on sonographic parameters and MOS. However, only clinical assessment reached statistical significance. Sixty-five of 312 (21 %) women were diagnosed with microtrauma. We found no evidence of impairment in PFM contractility on ultrasound, but there was a statistically significant reduction in MOS.

CONCLUSIONS

Both levator avulsion (macrotrauma) and irreversible overdistension (microtrauma) are associated with reduced contractile function. This effect is more easily detected by palpation than by sonographic indices of levator function.

Magnetic resonance imaging of the pelvic floor: from clinical to biomechanical imaging

This article reviews the current role of magnetic resonance imaging in the study of the pelvic floor anatomy and pelvic floor dysfunction. The application of static and dynamic magnetic resonance imaging in the clinical context and for biomechanical simulation modeling is assessed, and the main findings are summarized. Additionally, magnetic resonance-based diffusion tensor imaging is presented as a potential tool to evaluate muscle fiber morphology. In this article, focus is set on pelvic floor muscle damage related to urinary incontinence and pelvic organ prolapse, sometimes as a consequence of vaginal delivery. Modeling applications that evaluate anatomical and physiological properties of pelvic floor are presented to further illustrate their particular characteristics. Finally, finite element method is described as a method for modeling and analyzing pelvic floor structures' biomechanical performance, based on material and behavioral properties of the tissues, and considering pressure loads that mimic real-life conditions such as active contraction or Valsalva maneuver.

Inter-rater reliability of assessment of levator ani muscle strength and attachment to the pubic bone in nulliparous women

OBJECTIVES

The modified Oxford scale (MOS) has been found previously to have poor inter-rater reliability, whereas digital assessment of levator ani muscle (LAM) attachment to the pubic bone has been shown to have acceptable reliability. Our aim was to evaluate inter-rater reliability of the validated MOS and to develop a reliable classification system for digital assessment of LAM attachment, correlating this to findings on transperineal ultrasound (TPUS) examination.

METHODS

Evaluation of the MOS by palpation was performed in nulliparous women by two investigators. LAM attachment was evaluated using digital palpation, for which a novel classification system was developed with four grades based on the position of the attachment and presence of discernible muscle. Findings were compared with those on TPUS examination. Inter-rater reliability was assessed using Cohen's kappa statistic.

RESULTS

Twenty-five nulliparous women were examined. There was agreement in MOS scores between the investigators in 64% of women (n = 16), with a kappa of 0.66 (indicating substantial agreement). There was agreement in palpation of LAM attachment using the new grading system in 96% of women (n = 24), with a kappa of 0.90 (indicating almost perfect agreement). TPUS examination did not show LAM avulsion in any woman, with the exception of one with a partial avulsion.

CONCLUSION

In this group of nulliparous patients, there was substantial agreement between the two investigators in evaluation of the MOS and there was good agreement between grades of LAM attachment using the new classification system, which correlated with findings on TPUS examination. It therefore appears that these results are reproducible in nulliparous women and the techniques can be readily learned and reliably incorporated into clinical practice and research after appropriate training. Further research is required to establish clinical utility of the grading system for LAM attachment in postpartum women and in women with symptomatic pelvic organ prolapse.

Is levator avulsion a predictor of cystocele recurrence following anterior vaginal mesh placement?

OBJECTIVE

Levator avulsion has been shown to be a predictor of cystocele recurrence following anterior colporrhaphy. The aim of this study was to determine if levator avulsion is a risk factor for prolapse recurrence following anterior colporrhaphy with mesh.

METHODS

This was a retrospective analysis of data obtained from three surgical audits for subjective and objective outcomes following anterior colporrhaphy with mesh. Recurrence was defined as cystocele ≥ Stage 2 on the prolapse quantification system of the International Continence Society; symptoms of vaginal lump/bulge; or cystocele on ultrasound, defined as maximum bladder descent to ≥ 10 mm below the symphysis pubis. Levator avulsion was diagnosed using tomographic ultrasound imaging.

RESULTS

Two hundred and nine patients were followed up at a mean of 2.2 years (range, 3 months to 5.6 years) after anterior vaginal mesh placement. 24% (51/209) had recurrent prolapse symptoms, 33% (68/209) clinical cystocele recurrence ≥ Stage 2, and 26% (54/209) a recurrent cystocele on ultrasound. Twenty-eight out of 80 (35%) women with levator avulsion had significant sonographic cystocele recurrence (odds ratio (OR), 2.24 (95% confidence interval (CI), 1.13-4.43)). This finding was confirmed after adjusting for potential predictors of prolapse recurrence on multivariate logistic regression (OR, 2.13 (95% CI, 1.04-4.39); P = 0.04).

CONCLUSION

Levator avulsion doubles the risk of cystocele recurrence after anterior colporrhaphy with transobturator mesh.

A pictorial overview of pubovisceral muscle avulsions on pelvic floor magnetic resonance imaging

OBJECTIVES

Despite extensive research aimed at clarifying (failing) pelvic organ support, the complete aetiology of pelvic organ prolapse (POP) is still not fully understood. During vaginal delivery, the pelvic floor can be irreversibly traumatised, resulting in pubovisceral muscle avulsions. The aetiology of these avulsions is discussed in this pictorial overview. Normal female pelvic floor anatomy is described and variations are exemplified using magnetic resonance (MR) images. The clinical relevance of detecting pubovisceral muscle avulsions is specified.

METHODS

T2-weighted MR imaging has multiplanar capabilities with high diagnostic accuracy allowing for detailed visualisation of the pelvic floor. Together with the use of a three-dimensional (3D) post-processing program, the presence and severity of pubovisceral muscle avulsions can be quantified.

RESULTS

Pelvic floor MR imaging is a non-invasive method that enables adequate identification of pubovisceral muscle avulsions which are known risk factors for the development of POP. They can be scored with good to excellent inter- and intra-observer reliability.

CONCLUSIONS

Radiologists and urogynaecology subspecialists should be familiar with MR imaging findings of pubovisceral muscle avulsions as this birth-related trauma is observed in over 36 % of vaginally parous women.

TEACHING POINTS

• Pelvic organ prolapse (POP) is a growing problem for both patients and for our healthcare system • Pubovisceral muscle avulsions are known risk factors for pelvic organ prolapse (POP) • T2-weighted MR imaging visualises pubovisceral muscle avulsions adequately • Pubovisceral muscle avulsions are scored with good to excellent inter- and intra-observer reliability.

Pelvic floor trauma in childbirth

The investigation of female pelvic floor function and anatomy is moving from the fringes to the mainstream of urogynaecology and female urology, and it is becoming increasingly relevant for obstetrics. We are coming to realise that pelvic floor trauma in labour is common, usually overlooked, and a major factor in the causation of pelvic organ prolapse. Modern imaging methods such as magnetic resonance and 3D/4D ultrasound have enabled us to diagnose such trauma reliably and accurately, most commonly in the form of an avulsion of the puborectalis muscle; that is, a disconnection of the muscle from its insertion on the os pubis. Such damage to the levator muscle is macroscopically evident and can also be palpated, a skill that is available to every clinician, requiring neither investment nor specialised equipment. In this review, I will describe pelvic floor assessment by palpation and ultrasound and illustrate the commonest abnormalities and their clinical consequences. This paper will not focus on magnetic resonance imaging due to technical restrictions, cost and access issues in most jurisdictions, and because several papers have recently shown that ultrasound is at least as effective in diagnosing such trauma. Anal sphincter trauma is generally well covered in the literature and hence not subject of this review.

Comparison between transperineal ultrasound and digital detection of levator ani trauma. Can we improve the odds?

AIMS

To investigate the predictive ability of four digital assessment parameters to detect levator ani (LA) muscle defects (avulsion injury) and compare these to transperineal tomographic ultrasound images.

METHODS

This was an observational study imbedded in a larger quasi-experimental cohort study for women with urinary incontinence. Seventy-two women, ≥ 60 years who had attended or were going to attend physiotherapy for treatment of urinary incontinence, were included in the study. Inclusion criteria from the parent study were symptoms of stress, urge or both types of urinary incontinence. The predictive ability of the following digital parameters: direct palpation of a discontinuity of the LA muscle from insertion on the pubic ramus; palpation of the distance between the muscle insertion sites; palpation of LA strength; palpation of LA tone, were analyzed against findings from tomographic transperineal ultrasound images. Correlation between methods was measured using Cohen's kappa for each of the individual parameters.

RESULTS

Seventeen women (24%) presented with a complete or partial avulsion of the puborectalis muscle as diagnosed with tomographic ultrasound imaging. Nine women (13%) had complete avulsions, one of which was bilateral. The predictive ability of the digital assessment parameters varied from poor (k = 0.187, 95% CI [0.02-0.36]) to moderate (k = 0.569, 95% CI [0.31-0.83]). The new parameter of 'width between insertion sites' performed best.

CONCLUSIONS

Adding the parameter of "width between insertion sites" appears to enhance our ability to detect avulsion of the levator ani (LA) muscle by digital examination however it does not distinguish between unilateral or bilateral avulsion.

Diagnosis of levator avulsion injury: a comparison of three methods

OBJECTIVE

Levator avulsion is common after vaginal delivery and is strongly associated with prolapse and prolapse recurrence. The aim of this study was to compare assessment by digital palpation and two ultrasound methods, one using rendered volumes and the other multislice imaging, for the diagnosis of levator avulsion.

METHODS

We retrospectively analyzed randomly identified datasets of 266 women seen at a tertiary urogynecology unit. Each patient had undergone an interview, vaginal examination and 3D/4D translabial ultrasound examination. Analysis of the retrieved ultrasound volumes was performed offline, with the operator blinded to all clinical data, using two techniques: assessment of rendered volumes and evaluation on multislice imaging. We tested agreement between the three methods and the association of each method's results with symptoms and signs of pelvic organ prolapse.

RESULTS

Agreement between the findings on palpation and the two ultrasound methods with regard to diagnosis of levator avulsion ranged from 80% to 87% (Cohen's kappa, 0.35-0.56). The findings for all methods were significantly associated with symptoms, signs and ultrasound findings of pelvic organ prolapse (P=0.007 to < 0.001), with no single method appearing superior to the others.

CONCLUSIONS

Depending on the availability of local expertise and equipment, any of the three methods tested in this study may be used to document avulsion of the puborectalis muscle.