Appearance of the Levator Ani Muscle Subdivisions in Endovaginal Three-Dimensional Ultrasonography

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.

One-year follow-up after standardized perineal reconstruction in women with deficient perineum after vaginal delivery

INTRODUCTION

Perineal tears are common after childbirth and, if not surgically repaired, they may result in a deficient perineum that can cause symptoms of pelvic floor dysfunction. Perineal reconstruction aims to restore the perineal body and increase the support of the pelvic floor. The objective of the present study was to estimate symptom reduction after perineal reconstruction in patients with deficient perineum after vaginal delivery and to compare outcomes between participants with or without concomitant levator ani muscle deficiency.

MATERIAL AND METHODS

Participants presenting at the Karolinska Pelvic Floor Center with symptoms of deficient perineum at least 1 year after vaginal birth were invited to the study. Inclusion criteria were a visible perineal scar and confirmed anatomic defect. Levator ani defects were assessed using the Levator Ani Deficiency score. A perineal reconstruction was performed in a standardized way. Subjective symptoms were evaluated using the validated "Karolinska Symptoms After Perineal Tear Inventory" at baseline and 1-year follow-up. A score difference in the symptom of an acquired sensation of a wide vagina was the primary outcome. Results were stratified by the presence or absence of a levator ani deficiency.

RESULTS

A perineal reconstruction was performed in 131 patients and 128 patients completed the Karolinska Symptoms After Perineal Tear Inventory at baseline and 119 at follow-up. Median age was 36.1 (interquartile range [IQR] 7.9), median body mass index 22.3 (IQR 5.1) and a median of two vaginal deliveries. Fifty-four women (41.2%) had a levator ani deficiency. The mean score reduction for the item "Do you feel that your vagina is too wide/loose?" was -1.56 (SD 0.96; P < 0.001) from a mean score of 2.75 (maximum 3) at baseline. The mean total score reduction was -9.1 points (SD 5.3; P < 0.001) from a mean score of 18.4 (maximum 33) points at baseline. There were no significant differences between groups when stratifying by levator ani deficiency.

CONCLUSIONS

Our results show that perineal reconstructive surgery significantly decreases symptoms of deficient perineum after vaginal delivery. A concomitant levator ani defect does not affect the symptom reduction of an acquired sensation of a wide vagina or the total score reduction after surgery.

Three-dimensional endovaginal ultrasound assessment using the levator ani deficiency score in primiparas: A replication study

INTRODUCTION

It is essential to assess the levator ani properly as part of clinical care in patients presenting with pelvic floor dysfunction. The levator ani deficiency scoring system is a previously published method to assess levator ani defects with three-dimensional endovaginal ultrasound. The primary aim of this study was to determine the intra- and interrater reliability of the levator ani deficiency score in a cohort of non-instrumentally delivered primiparas.

MATERIAL AND METHODS

Primiparas (n = 141) were examined at least 1 year after vaginal birth. Three-dimensional endovaginal ultrasound volumes were acquired by a single examiner using two different automated ultrasound probes. The volumes were analyzed by two separate raters who were blinded to each other's assessments. Descriptive statistics were calculated for levator ani deficiency score and categorized into three levels (mild, moderate, severe). Kendall's tau-b was calculated for intra- and interrater comparisons.

RESULTS

Intrarater comparisons of levator ani deficiency score and levator ani deficiency category were high (Kendall's tau-b ≥0.80 for Rater 1; >0.79 for Rater 2). Interrater comparisons of levator ani deficiency score and levator ani deficiency category were also high (Kendall's tau-b >0.9 for assessment 1 and >0.78 for assessment 2). Varying by rater, probe and assessment, 75.9%-80.1% of the study population had no/mild deficiency, 6.4%-9.2% had moderate deficiency, and 4.3%-6.4% had severe levator ani deficiency.

CONCLUSIONS

The levator ani deficiency scoring system is a feasible method to assess defects of the levator ani muscle and can be reproduced with high intra- and interrater correlations. Using the scoring system in clinical practice may facilitate concordant assessment between different examiners. However, the system should be used to support clinical findings and symptomatology and not as a screening tool, as the score is lacking the category of no levator ani deficiency.

Levator ani muscle volume and architecture in normal vs. muscle damage patients using 3D endovaginal ultrasound: a pilot study

INTRODUCTION AND HYPOTHESIS

This study aimed to compare the difference in levator ani muscle (LAM) volumes between 'normal' and those with sonographically visualized LAM defects. We hypothesized that the 'muscle damage' group would have a significantly lower muscle volume.

METHODS

The study included patients who had undergone a 3D endovaginal ultrasound. The normal (NM) and damage (DM) muscle groups' architectural changes were evaluated based on anterior-posterior (AP), left-right (LR) diameter, and minimal levator hiatus (MLH) area. The puboanalis-puboperinealis (PA), puborectalis (PR), and pubococcygeus-iliococcygeus (PC) were manually segmented using 2.5 vs. 1.0 mm to find the optimal sequence and to compare the volumes between NM and DM groups. POPQs were compared between the NM and DM groups.

RESULTS

The 1.0-mm segmentation volumes created superior volume analysis. Comparing NM to the DM group showed no significant difference in LAM volume. Respectively, the mean total LAM volumes were 17.27 cm³ (SD = 3.97) and 17.04 cm³ (SD = 4.32), p = 0.79. The mean MLH measurements for both groups respectively were 10.06 cm² (SD = 2.93) and 12.18 cm² (SD = 2.93), indicating a significant difference (p = 0.01). POPQ analysis demonstrated statistically significant differences at Ba and Bp parameters suggesting that the DM group had worse prolapse (p = 0.05, 0.01, respectively).

CONCLUSIONS

While LAM volumes are similar, there is a significant difference in the physical architecture of the LAM and the POPQ parameters in muscle-damaged patients compared to the normal group.

Episiotomy in vacuum extraction, do we cut the levator ani muscle? A prospective cohort study

INTRODUCTION AND HYPOTHESIS

Vaginal delivery may lead to levator ani muscle (LAM) injury or avulsion. Episiotomy may reduce obstetric anal sphincter injury in operative vaginal delivery, but may increase the risk of LAM injury. Our aim was to assess whether lateral episiotomy in vacuum extraction (VE) in primiparous women causes LAM injury.

METHODS

A prospective cohort study of 58 primiparous women with episiotomy nested within an ongoing multicenter randomized controlled trial of lateral episiotomy versus no episiotomy in VE (EVA trial) was carried out in Sweden. LAM injury was evaluated using 3D endovaginal ultrasound 6-12 months after delivery and Levator Ani Deficiency (LAD) score. Episiotomy scar properties were measured. Characteristics were described and compared using Chi-squared tests. We stipulated that if a lateral episiotomy cuts the LAM, ≥50% would have a LAM injury. Among those, ≥50% would be side specific. We compared the observed prevalence with a test of one proportion.

RESULTS

Twelve (20.7%, 95% CI 10.9-32.9) of 58 women had a LAD (p < 0.001, compared with the stipulated 50%). Six (50.0%, 95% CI 21.1% to 78.9%) of 12 women had a LAD on the episiotomy side, including those with bilateral LAD (p = 1.00). Two (16.7%, 95% CI 2.1% to 48.4%) of 12 women had a LAD exclusively on the episiotomy side (p = 0.02).

CONCLUSIONS

There was no excessive risk of cutting the LAM while performing a lateral episiotomy. LAD was not seen in women with episiotomies shorter than 18 mm.

Anal canal coronal-sagittal ratio: a novel parameter for diagnosing pelvic floor injury in two-dimensional transanal ultrasound

Purpose

Pelvic floor injury diagnosis using 3-dimensional (3D) pelvic floor ultrasound or magnetic resonance imaging is unfeasible in many clinics. We assessed the efficacy of a novel diagnostic parameter, the anal canal coronal-sagittal (CS) ratio, for pelvic floor injury on 2-dimensional [2D] transanal ultrasound.

Methods

This retrospective study analyzed the data of 126 female patients who underwent 3D pelvic floor ultrasound (including 2D transanal ultrasound) at a pelvic floor center between August and December 2020. The anal canal CS ratio on 2D transanal ultrasound and pelvic floor avulsion injury measurements were recorded for all patients.

Results

A cutoff anal canal CS ratio of 1.15 was obtained using receiver operating characteristic analysis (sensitivity, 0.820; specificity, 0.763; and area under the curve, 0.838). Patients were categorized into the anal canal CS ratio ≥1.15 and the anal canal CS ratio <1.15 groups. Bilateral pelvic floor avulsion was more common in the anal canal CS ratio ≥1.15 group (n=35, 56.5%), and the incidence of pelvic floor avulsion was significantly different between the 2 groups (P=0.001). Existing parameters of pelvic floor injury, including minimal levator hiatus (P=0.001), levator plate descent angle (P=0.001), and levator ani deficiency score (P=0.001), were statistically different between the 2 groups.

Conclusion

The anal canal CS ratio was an efficient novel parameter that indirectly detected pelvic floor injury in 2D transanal ultrasound. It is a potential alternative indicator for pelvic floor injury on the widely popular 2D transanal ultrasound.

Correlation between pelvic floor ultrasound parameters and vaginal pressures in nulliparous women: a subanalysis of the SUM-AN study

INTRODUCTION AND HYPOTHESIS

Pelvic floor ultrasound is used as a validated technique for measuring levator ani dimensions. Vaginal manometry has been used in the past as a method to assess levator ani muscle (LAM) strength. Whether the combination of both methods can contribute to our understanding of pelvic floor pathophysiology has not yet been described. We hypothesized that as female pelvic floor muscular hiatus increases, the vaginal pressure and strength decrease.

METHODS

We recruited 20 asymptomatic nulliparous women ages 18-85 years. Minimal levator hiatus (MLH) area, anteroposterior/left-right (AP/LR) diameter ratio, the distance between levator plate and the pubic symphysis (LP-PS) while at rest and squeeze were measured using endovaginal ultrasound (US). Vaginal pressure at rest, squeeze (Kegel) and Valsalva were measured using 3D manometry. Logistic and linear regression analysis was performed to assess correlations.

RESULTS

MLH area was negatively correlated with the sum of all the squeeze pressures produced on the four walls of the vagina (p = 0.049, R² = 0.197). There was also a borderline negative correlation between MLH and the sum of rest pressures (p = 0.09, R² = 0.15). AP/LR ratio was negatively correlated with the sum of squeeze pressures (p = 0.056, R² = 0.197). LP-PS distances, both while at rest and during squeeze, were negatively correlated with the vaginal squeeze pressure (p = 0.046, R² = 0.21; p = 0.011, R² = 0.31, respectively). LP-V distance, both at rest and during squeeze, was negatively correlated with the sum of squeeze pressures on four vaginal walls (p = 0.02, R² = 0.25; p = 0.005, R² = 0.36, respectively).

CONCLUSIONS

Stronger levator ani muscles, smaller MLH area and a more oval shape of pelvic floor hiatus as assessed by pelvic floor ultrasound are associated with higher squeeze vaginal pressures as assessed by 3D manometry.

Ultrasonographic Imaging of the Pelvic Floor

This article discusses various pelvic floor ultrasonographic modalities and the clinical applications of ultrasonography of the pelvic floor. Ultrasonography provides a detailed anatomic assessment of the muscles and surrounding organs of the pelvic floor. Different anatomic variabilities and pathologic conditions, such as prolapse, fecal incontinence, urinary symptoms, vaginal wall cysts, synthetic implanted material, and pelvic pain, are assessed with pelvic floor ultrasonography. This imaging modality is an important adjunct to the evaluation and diagnosis of pelvic floor disorders.

Three-Dimensional Pelvic Floor Ultrasound Assessment of Pelvic Organ Prolapse: Minimal Levator Hiatus and Levator Ani Deficiency Score

Purpose

The purpose of this study was to determine whether levator ani deficiency (LAD) scores and minimal levator hiatus (MLH) areas affect Pelvic Organ Prolapse Quantification (POP-Q) stage.

Methods

This study was a retrospective chart review of patients with pelvic organ prolapse (POP) at Seoul Songdo Hospital between August 2019 and August 2020. Three-dimensional (3D) pelvic floor ultrasound, preoperative anal manometry, and other physiological tests were performed in 78 patients with POP symptoms. We divided the patients into mild prolapse and severe prolapse groups based on the POP-Q. We examined the LAD and MLH areas. LAD scores were categorized as mild, moderate, or severe.

Results

There were 32 patients (41.0%) in the mild prolapse group (POP-Q stage I and II) and 46 (59.0%) in the severe prolapse group (POP-Q stage III and IV). The mean LAD score was significantly higher in severe prolapse group (13.33±2.49 vs. 8.19±2.92, P<0.001), and the rate of severe deficiency was also significantly higher in the severe prolapse group (29 [63.0%] vs. 2 [6.3%], P<0.001). The mean MLH was also significantly larger in the severe prolapse group (17.91±2.74 cm² vs. 14.95±2.60 cm², P<0.001). In addition, both MLH and LAD scores tended to increase at each stage.

Conclusion

There is a strong positive correlation between the POP-Q stage and the MLH and LAD scores that can be seen on 3D pelvic floor ultrasound. The findings of this study, by objectively demonstrating LAD and MLH in women with POP, are an important contribution to POP.

Levator plate descent angle in pelvic floor disorders

BACKGROUND

The levator plate descent angle (LPDA) quantifies the levator plate position with reference to the pubic bone and perineal body at rest. Unfortunately, research on this notable new parameter is lacking, but it is clear that levator ani deficiency (LAD) will undermine the fundamental role of the levator ani muscle (LAM) in organ support. The aim of this study was to establish the relationship between the LPDA and LAD in patients with pelvic floor disorders.

METHODS

This retrospective study was conducted at Seoul Songdo Hospital, Korea between August 2019 and August 2020 on women with symptoms of pelvic floor disorder such as urinary incontinence, constipation, and fecal incontinence. In all cases, three-dimensional pelvic floor ultrasound was performed for LAD scoring, minimal levator hiatus, and LPDA evaluation. We evaluated LAD using a scoring system that graded levator injury according to the insertion point of each subdivision scored unilaterally. For the entire LAM group, a cumulative LAD score that ranged between 0 and 18 was possible. Scores were categorized as mild (0-6 points), moderate (7-12 points), and severe (13-18 points) deficiency RESULTS: A total of 93 patients were included in the study (mean age 65.89 ± 11.12 [range, 34-86] years). Thirteen participants had mild LAD scores (14.0%), 42 had moderate LAD scores (45.2%), and 38 had severe LAD scores (40.9%). There was a significant difference in mean age (59.23 ± 12.55 years vs. 64.43 ± 10.03 vs. 69.79 ± 10.55 years, p = 0.005) and mean parity (1.85 ± 0.90 vs 2.48 ± 1.15 vs 2.76 ± 1.10, p = 0.038) of patients between groups. There was also a significant difference in the mean Wexner incontinence score (7.14 ± 3.63 vs 7.24 ± 5.76 vs 11.41 ± 5.54, p = 0.028) and in the mean fecal incontinence quality of life (FIQOL) score (12.91 ± 3.11 vs 14.10 ± 3.87 vs 10.41 ± 3.65, p = 0.014). The mean value of the LPDA in the group with mild LAD scores was 14.65° (SD ± 3.54) and in the group with moderate LAD scores was 9.66° (SD ± 3.36). In the group with severe LAD scores, the mean LPDA was 1.83° (SD ± 4.71). The mean value for minimal levator hiatus (MLH) area in the mild LAD score group was 14.16cm² (SD ± 2.72), that in the moderate LAD score group was 15.82cm² (SD ± 2.30), and that in the severe LAD score group was 17.99cm² (SD ± 2.81). There were significant differences between the three groups both in decreasing LPDA (p < 0.001) and increasing MLH (p < 0.001). There was a negative correlation between the LAD score and LPDA and the Pearson correlation coefficient was -0.528 (moderate correlation). There was a positive correlation between the LAD score and MLH, and the Pearson correlation coefficient was 0.303 (weak correlation).

CONCLUSIONS

The LAD score and LPDA have a moderate negative correlation. In patients with severe pelvic floor symptoms and extensive LAM injury, high LAD scores and low LPDA results were confirmed. In the treatment of patients with pelvic floor disorders, the LPDA seems to be a very useful parameter in determining the severity of structural defects.

Appearance of the levator ani muscle subdivisions on 3D transperineal ultrasound

BACKGROUND

The levator ani muscle (LAM) consists of different subdivisions, which play a specific role in the pelvic floor mechanics. The aim of this study is to identify and describe the appearance of these subdivisions on 3-Dimensional (3D) transperineal ultrasound (TPUS). To do so, a study designed in three phases was performed in which twenty 3D TPUS scans of vaginally nulliparous women were assessed. The first phase was aimed at getting acquainted with the anatomy of the LAM subdivisions and its appearance on TPUS: relevant literature was consulted, and the TPUS scan of one patient was analyzed to identify the puborectal, iliococcygeal, puboperineal, pubovaginal, and puboanal muscle. In the second phase, the five LAM subdivisions and the pubic bone and external sphincter, used as reference structures, were manually segmented in volume data obtained from five nulliparous women at rest. In the third phase, intra- and inter-observer reproducibility were assessed on twenty TPUS scans by measuring the Dice Similarity Index (DSI).

RESULTS

The mean inter-observer and median intra-observer DSI values (with interquartile range) were: puborectal 0.83 (0.13)/0.83 (0.10), puboanal 0.70 (0.16)/0.79 (0.09), iliococcygeal 0.73 (0.14)/0.79 (0.10), puboperineal 0.63 (0.25)/0.75 (0.22), pubovaginal muscle 0.62 (0.22)/0.71 (0.16), and the external sphincter 0.81 (0.12)/0.89 (0.03).

CONCLUSION

Our results show that the LAM subdivisions of nulliparous women can be reproducibly identified on 3D TPUS data.

The Prevalence of Pelvic Floor Hematoma After Vaginal Delivery

OBJECTIVE

The goal of this study was to evaluate differences in levator ani hematoma formation within 3 days of delivery between adult women after their first vaginal delivery and adult women who have had multiple vaginal deliveries.

METHODS

This was a cross-sectional study at a single institution from 2013 to 2015 using a high-resolution endovaginal ultrasound transducer to identify postvaginal delivery hematoma formation. Logistic regression was used to examine the association between hematoma formation and vaginal parity while considering potential confounders including induction, vaginal operative delivery, vaginal birth after cesarean, fetal weight, fetal head circumference, race and ethnicity, body mass index, age at delivery, gestational age, and length of second-stage labor.

RESULTS

Ninety women (46 vaginal-primiparous; 44 vaginal-multiparous) were included in this study. After adjusting for oxytocin use, length of second-stage labor, and body mass index, the odds of pelvic floor hematoma of 1000 mm3 or greater were 2.93 (95% confidence interval, 0.78-10.91) times greater in women after their first vaginal delivery compared with women with a history of multiple vaginal deliveries. The adjusted odds of pelvic floor hematoma of 1500 mm3 or greater were 6.02 (95% confidence interval, 1.09-33.24) times greater in vaginal-primiparous compared with vaginal-multiparous women.

CONCLUSIONS

Although the prevalence of pelvic floor hematoma was higher in vaginal-primiparous women than vaginal-multiparous women after vaginal delivery, hematomas were present in both groups. Future prospective studies are needed to evaluate the additive effect of multiple vaginal deliveries on the pelvic floor.

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.

Comparison of 3-Dimensional Pelvic Floor Ultrasonography and Defecography for Assessment of Posterior Pelvic Floor Disorders

PURPOSE

The aim of this study was to determine the accuracy of 3-dimensional (3D) pelvic floor ultrasonography and compare it with defecography in assessment of posterior pelvic disorders.

METHODS

Eligible patients were consecutive women undergoing 3D pelvic floor ultrasonography at one hospital between August 2017 and February 2019. All 3D pelvic floor ultrasonography was performed by one examiner. A total of 167 patients with suspected posterior pelvic disorder was retrospectively enrolled in the study. The patients were divided into 3 groups according to the main symptoms.

RESULTS

There were 82 rectoceles on defecography (55 barium trapping) and 84 on 3D pelvic floor ultrasonography. Each modality identified 6 enteroceles. There were 43 patients with pelvic floor dyssynergia on defecography and 41 on ultrasonography. There were 84 patients with intussusception on defecography and 41 on 3D pelvic floor ultrasonography. Agreement of the 2 diagnostic tests was confirmed using Cohen's kappa value. Rectocele (kappa, 0.784) and enterocele (kappa, 0.654) both indicated good agreement between defecography and 3D pelvic floor ultrasonography. In addition, pelvic floor dyssynergia (kappa, 0.406) showed moderate agreement, while internal intussusception (kappa, 0.296) had fair agreement.

CONCLUSION

This study showed good agreement for detection of posterior pelvic disorders between defecography and 3D pelvic floor ultrasonography.

New Measures for Predicting Birth-Related Pelvic Floor Trauma

OBJECTIVES

The aim of this study was to establish the predictive role of obstetric variables for obstetric outcomes and birth related levator ani muscle (LAM) trauma.

METHODS

In this prospective study, women underwent 3-dimensional pelvic floor ultrasound at their first appointment at 36 weeks and also 3 months postpartum. The measurements included minimal levator hiatus circumference (MLHC) and the ratio of fetal head circumference to MLHC = head-induced stretch ratio (HISR) as an indicator of the discrepancy between passage and passing canal. To derive the true impact of baby's mass on the levator ani musculature, we devised the levator ani stretch ratio (LASR), which was calculated by multiplying the HISR and the baby's weight.

RESULTS

Data set of 173 women was available for analysis. Mean HISR and LASR values were statistically different across all binary outcome categories, with 1 exception for HISR and levator ani injury. The odds ratios for LASR indicated positive and statistically significant associations with all obstetric outcomes examined. The probability of the LASR correctly classifying those with the adverse obstetric outcome, as estimated by the area under the curve, ranged from 0.64 to 0.80 with the strongest discriminatory ability observed for severe LAM trauma.

CONCLUSIONS

Fetal head circumference/mother MLHC ratio (HISR) is associated with longer length of second stage of labor, assisted delivery, and increased severity of perineal trauma. Similar associations were observed for LASR, but in addition, LASR had good discriminatory ability to identify severe LAM trauma.

Increasing Age Is a Risk Factor for Decreased Postpartum Pelvic Floor Strength

OBJECTIVES

This study aimed to determine factors associated with decreased pelvic floor strength (PFS) after the first vaginal delivery (VD) in a cohort of low-risk women.

METHODS

This is a secondary analysis of a prospective study examining the risk of pelvic floor injury in a cohort of primiparous women. All recruited participants underwent an examination, three-dimensional ultrasound and measurement of PFS in the third trimester and repeated at 4 weeks to 6 months postpartum using a perineometer.

RESULTS

There were 84 women recruited for the study, and 70 completed the postpartum assessment. Average age was 28.4 years (standard deviation, 4.8). There were 46 (66%) subjects with a VD and 24 (34%) with a cesarean delivery who labored. Decreased PFS was observed more frequently in the VD group compared with the cesarean delivery group (68% vs 42%, P = 0.03).In modified Poisson regression models controlling for mode of delivery and time of postpartum assessment, women who were aged 25 to 29 years (risk ratio = 2.80, 95% confidence interval, 1.03-7.57) and 30 years and older (risk ratio = 2.53, 95% confidence interval, 0.93-6.86) were over 2.5 times more likely to have decreased postpartum PFS compared with women younger than 25 years.

CONCLUSIONS

In this population, women aged 25 years and older were more than twice as likely to have a decrease in postpartum PFS.

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.

Perineal body anatomy seen by three-dimensional endovaginal ultrasound of asymptomatic nulliparae

AIM

The perineal body (PB) plays an important role in supporting the pelvic floor and the posterior vaginal wall, but its attachments and relationships are still debated. This study aimed to assess the normal anatomy of the PB using high-resolution three-dimensional endovaginal ultrasound (3D-EVUS) in asymptomatic nulliparae.

METHOD

To validate the identification of perineal structures, 3D-EVUS was initially performed on nulliparous cadavers. Fresh frozen pelves were prepared and echogenic structures thought to be the PB, the external anal sphincter, the superficial and deep transverse perineii, pubovaginalis, puboperinealis, puboanalis, puborectalis and iliococcygeus muscles were tagged with biopsy needles, and marked with indigo carmine dye for localization during dissection. In the second part of the study, consecutive asymptomatic nulliparae were prospectively imaged with the same ultrasound modality. Interrater reproducibility was assessed off-line from stored 3D US volumes using a standardized technique.

RESULTS

Five fresh frozen pelves and 44 asymptomatic nulliparae were assessed with 3D-EVUS. The PB was seen as an ovoid structure of mixed echogenicity between the rectum and vagina. It appeared to be divided into a superficial level, in contact with the external anal sphincter, the bulbospongiousus and the superficial transverse perineii muscle and a deep level, in contact with puboperinealis and puboanalis muscles. Interobserver repeatability was excellent for the measurements of PB height [intraclass correlation coefficient (ICC) 0.927], PB depth (ICC 0.969) and PB width (ICC 0.932).

CONCLUSION

The PB is divided into two levels with different anatomical relationships with the pelvic floor muscles. 3D-EVUS yields reproducible assessment of this complex structure.

Interobserver agreement of multicompartment ultrasound in the assessment of pelvic floor anatomy

OBJECTIVE

To assess the interobserver agreement of pelvic floor anatomical measurements using multicompartment pelvic floor ultrasound.

METHODS

Females were recruited from the urogynaecology/gynaecology clinics between July and October 2009 and underwent multicompartment pelvic floor ultrasonography (PFUS) using two-dimensional (2D) transperineal ultrasound (TPUS), high-frequency 2D/three-dimensional (3D) endovaginal ultrasound (EVUS) using a biplane probe with linear and transverse arrays and a 360° rotational 3D-EVUS. PFUS measurements were independently analysed by two clinicians.

RESULTS

158 females had PFUS assessment. Good-to-excellent interobserver agreement was observed for bladder-symphysis distance at rest and valsalva, urethral thickness, urethral length, urethral volume, levator hiatus area and width, anteroposterior diameter and anorectal angle. Lins Correlation was used to calculate the interobserver agreement and Bland-Altman plots were created to demonstrate the agreement between the researchers. There was also a good-to-excellent agreement between the two clinicians for the assessment of pelvic organ prolapse (POP) in the anterior, middle and posterior compartment.

CONCLUSION

Multicompartment PFUS is a reliable tool in the anatomical assessment of pelvic floor measurements and POP.

ADVANCES IN KNOWLEDGE

We found a good-to-excellent agreement between the two assessors in the assessment of pelvic floor measurements for all three pelvic floor compartments and suggest that multicompartment PFUS could be considered as a systematic integrated approach to assess the pelvic floor.

How does 3D endovaginal ultrasound compare to magnetic resonance imaging in the evaluation of levator ani anatomy?

INTRODUCTION AND HYPOTHESIS

To compare magnetic resonance imaging (MRI) to 3D endovaginal ultrasound (EVUS) in the evaluation of major levator ani defects in women with pelvic floor disorders.

METHODS

A total of 21 subjects with pelvic floor with complaints of pelvic floor disorders were included in this study. EVUS imaging of the levator ani muscle (LAM) was performed in all subjects, and the LA muscle groups of interest evaluated were the puboanalis (PA), puborectalis (PR), and pubovisceralis (PV) muscles. The right and left subdivisions were evaluated separately, and classified as (i) normal, normal with only minor irregularities, grossly abnormal, or absent, or (ii) by the levator ani deficiency (LAD) score and classified by no defect (complete attachment of muscle to the pubic bone), <50% detachment or loss, >50% detachment or loss, and completely detached or complete muscle loss. Paired data were analyzed with McNemar's test or Bowker's test of symmetry.

RESULTS

When unilateral LAM subdivisions were classified as "normal," "normal with minor irregularity," "grossly abnormal," and "absent," there were no significant differences between MRI and EVUS by categorization of LAM defects. Comparing "normal" versus "abnormal," there was no difference between imaging modalities. When compared by LAD score evaluation, there were no differences in the categorization of unilateral defects between MRI and EVUS.

CONCLUSIONS

Endovaginal 3D US is comparable to MRI in its ability to identify both normal and abnormal LAM anatomy. Neurourol. Urodynam. 36:409-413, 2017. © 2015 Wiley Periodicals, Inc.

Characteristics associated with pelvic organ prolapse in women with significant levator ani muscle deficiency

INTRODUCTION AND HYPOTHESIS

Age is a factor associated with symptomatic pelvic organ prolapse (POP) among women with significant levator ani deficiency.

METHODS

This cross-sectional study included patients who were referred for varied pelvic floor disorders, had 3D endovaginal ultrasound as part of their evaluation, and were diagnosed with significant levator ani muscle deficiency defined as a score of 12 or more on 3D endovaginal ultrasound. Patients were categorized as having no pelvic organ prolapse (stages 0 and 1), or symptomatic prolapse (stages 2-4).

RESULTS

Seventy-six women were available for analysis and found to have significant levator ani muscle deficiency, including 51 with symptomatic POP and 25 without POP. Patients with symptomatic POP were older, (mean age 66 (SD ± 11.8) vs 48 (SD ± 17.3) years; p <0.0001), had greater mean minimal levator hiatus (MLH) area (19.7 cm(2) (SD ± 4.6) vs 17.5 cm(2) (SD ± 3.5); p = 0.048), and were more likely to be menopausal (91.3 % vs 54.5 %; p <0.001) compared with those with no POP. In a modified Poisson regression analysis excluding nulliparous women, increasing age (RR = 2.39, 95 % CI 1.03-5.55) and smoking (RR = 1.34, 95 % CI 1.08-1.67) remained associated with symptomatic POP after controlling for one another and the MLH area.

CONCLUSIONS

Among women with significant levator ani deficiency, older women and smokers had an increased prevalence of symptomatic POP. On average, women without POP, but with significant levator ani deficiency were 18 years younger than women with POP and significant muscle deficiency.

Is a new high-resolution probe better than the standard probe for 3D anal sphincter and levator ani imaging?

The aim of our study was to determine the accuracy of a new three-dimensional (3D) endoluminal ultrasound probe in assessing the levator ani muscle and anal sphincter complex. A total of 85 patients who had undergone concurrent 3D endovaginal (EVUS) and 3D endoanal (EAUS) ultrasound with both the standard BK 2052 probe and the new high-definition BK 8838 probes were included. For EVUS volumes, the levator ani deficiency (LAD) scores were calculated for each probe. For the EAUS volumes, any defects in the external anal sphincter (EAS) and the internal anal sphincter (IAS) visualized with each probe were recorded. The 3D volumes were evaluated in a blinded fashion. Appropriate statistics were utilized to assess absolute agreements between each pair of imaging modalities. The mean age of the patient population was 59 years (SD ± 10.76), the mean body mass index (BMI) was 28.36 (SD ± 5.99), and the median parity was 2 (range 1, 7). In all, 93% of the patients were Caucasian, 31% had stage 0 or 1 prolapse, while 59% had stage 2 prolapse. The mean total LAD score obtained on EVUS with the standard and the new probes were 11.49 (SD ± 4.94) and 11.53 (SD ± 5.01), respectively, p = 0.3778. Among the 53 patients who had EAUS with both probes, exact agreement for visualization of EAS and IAS for the standard and the new probes was 83% and 98%, respectively. Both transducers can be used for endovaginal imaging of the levator ani muscles interchangeably. Both transducers can be used for endoanal imaging of anal sphincter complex interchangeably.

How well can levator ani muscle morphology on 3D pelvic floor ultrasound predict the levator ani muscle function?

INTRODUCTION AND HYPOTHESIS

The aim of our study was to assess the performance of levator ani muscle deficiency (LAD) evaluated by 3D endovaginal ultrasound (EVUS) to detect pelvic floor muscle function as assessed by digital examination.

METHODS

This cross-sectional study was conducted among 77 patients referred to our urogynecology clinic for pelvic floor dysfunction symptoms. Patients underwent physical examinations including digital pelvic muscle strength assessment using the Modified Oxford scale (MOS). EVUS volumes were evaluated and levator ani muscles were scored according to a validated LAD scoring system. MOS scores were categorized as nonfunctional (scores 0-1) and functional (scores 2-5).

RESULTS

Mean age of participants was 56 (SD ± 12.5) and 71% were menopausal. Overall, 32.5% had nonfunctional muscle strength and 44.2% were classified as having significant LAD. LAD identified by ultrasound had a sensitivity of 60% (95% CI 41 -79%) for detecting nonfunctional muscle and a specificity of 63% (95% CI 50 -77%) for detecting functional muscle. Overall, LAD demonstrated fair ability to discriminate between patients with and those without poor muscle function (area under the ROC curve = 0.70 [95% CI 0.58-0.83]). Among patients with an LAD score of 16-18, representing almost total muscle avulsion, 70% had nonfunctional MOS scores, whereas in patients with normal/minimal LAD (scores of 0-4), 89.5% had functional MOS scores.

CONCLUSIONS

Levator ani deficiency and MOS scales were moderately negatively correlated. Among patients with normal morphology or the most severe muscle deficiency, LAD scores can identify the majority of patients with functional or nonfunctional MOS scores respectively.

Is there a correlation between levator ani and urethral sphincter complex status on 3D ultrasonography?

INTRODUCTION AND HYPOTHESIS

To determine the correlation between levator ani deficiency (LAD) and urethral sphincter complex measurements as visualized on 3D endovaginal ultrasonography, and to compare the LAD score with continence status.

METHODS

This was a retrospective analysis of patients seen at our institution between January 2011 and August 2013. Patients were dichotomized into those with urodynamic stress urinary incontinence (SUI) and those with no SUI. Levator ani status was evaluated using a validated scoring system yielding scores of 0 - 6 (normal levator ani/mild LAD), 7 - 12 (moderate LAD), and 13 - 18 (severe LAD). The length, horizontal diameter, and cross-sectional area of the urethra, and the length, width, and the area of the rhabdomyosphincter and smooth muscle sphincter were likewise measured using 3D ultrasound volumes.

RESULTS

Of the 80 patients included, 54 (67.5%) had SUI and 26 (32.5%) were continent. 18 (22.5%) had evidence of mild LAD, 54 (67.5%) had moderate LAD, and 8 (10.0%) had severe LAD. Among patients with SUI, those with normal levator ani muscles or mild LAD had greater urethral smooth muscle width than those with moderate and severe LAD (p = 0.0238). A greater proportion of patients with SUI also had moderate to severe LAD than continent patients (p = 0.0177, OR 3.59, 95% CI 1.21 - 10.65). There was no difference in LAD distribution by type of stress incontinence (presence or absence of intrinsic sphincter deficiency; p =  .2377).

CONCLUSIONS

LAD and urethral sphincter complex status, as visualized on 3D ultrasonography, are independent factors. Moderate to severe LAD is more prevalent in patients with SUI.

The value of pre-operative multicompartment pelvic floor ultrasonography: a 1-year prospective study

OBJECTIVE

Comprehensive assessment of the pelvic floor (PF) provides information and diagnoses of coexisting abnormalities that may affect operative decisions. Our aim was to establish if pre-operative PF ultrasonography (PFUS) in patients complaining of PF dysfunction can complement clinical findings and contribute to additional management strategies.

METHODS

Females were recruited from the urogynaecology/gynaecology clinics between July and October 2009 and underwent pelvic organ prolapse quantification (POPQ) by an independent examiner. PFUS was performed using two-dimensional (2D) transperineal ultrasound (TPUS), high-frequency 2D/three-dimensional (3D) endovaginal ultrasound (EVUS) using a biplane probe with linear and transverse arrays and a 360° rotational 3D-EVUS. The clinician performing PFUS was blinded to POPQ results. POPQ and PFUS were repeated at 1 year. Two clinicians analysed the scans independently.

RESULTS

158 of 160 females had a POPQ and PFUS. 105 females had pelvic organ prolapse and/or incontinence and 53 asymptomatic females were controls. 26 additional ultrasound diagnoses were noted at baseline and 46 at 1 year using 2D-TPUS and EVUS. Only one female with additional diagnoses on PFUS needed surgical intervention for this condition.

CONCLUSION

Multicompartment PFUS identifies additional conditions to that diagnosed on clinical assessment. However, it neither changes the initial surgical management nor the management at 1-year follow-up and therefore clinical assessment should not be substituted by PFUS.

ADVANCES IN KNOWLEDGE

PFUS can be helpful in providing additional information; however, it does not change the initial management of the patient and therefore should not replace clinical assessment.

Continence and micturition: an anatomical basis

Urinary incontinence remains an important clinical problem worldwide, having a significant socio-economic, psychological, and medical burden. Maintaining urinary continence and coordinating micturition are complex processes relying on interaction between somatic and visceral elements, moderated by learned behavior. Urinary viscera and pelvic floor must interact with higher centers to ensure a functionally competent system. This article aims to describe the relevant anatomy and neuronal pathways involved in the maintenance of urinary continence and micturition. Review of relevant literature focusing on pelvic floor and urinary sphincters anatomy, and neuroanatomy of urinary continence and micturition. Data obtained from both live and cadaveric human studies are included. The stretch during bladder filling is believed to cause release of urothelial chemical mediators, which in turn activates afferent nerves and myofibroblasts in the muscosal and submucosal layers respectively, thereby relaying sensation of bladder fullness. The internal urethral sphincter is continuous with detrusor muscle, but its arrangement is variable. The external urethral sphincter blends with fibers of levator ani muscle. Executive decisions about micturition in humans rely on a complex mechanism involving communication between several cerebral centers and primitive sacral spinal reflexes. The pudendal nerve is most commonly damaged in females at the level of sacrospinous ligament. We describe the pelvic anatomy and relevant neuroanatomy involved in maintaining urinary continence and during micturition, subsequently highlighting the anatomical basis of urinary incontinence. Comprehensive anatomical understanding is vital for appropriate medical and surgical management of affected patients, and helps guide development of future therapies.

Intra- and interobserver reliability of levator ani muscle biometry and avulsion using three-dimensional endovaginal ultrasonography

OBJECTIVES

To test intra- and interobserver reliability of assessment of levator ani muscle (LAM) biometry and avulsion using antenatal and postnatal three-dimensional (3D) endovaginal ultrasonography (EVUS), and to determine levator-urethra gap (LUG) values on EVUS.

METHODS

Primigravid women were scanned prior to delivery, early postpartum and 3 months postpartum, with EVUS performed at rest using a standardized protocol. During post-processing, measurements were taken in the plane of minimal hiatal dimensions by two independent investigators blinded to the clinical information and each other's results. LAM attachment to the pubic bone was assessed at the pubococcygeus and puborectalis levels using a score system: (1) intact; (2) partial avulsion (< 50%); (3) partial avulsion (≥ 50%); and (4) complete avulsion. Intraclass correlation coefficients (ICCs) and limits of agreement (LOAs) were calculated for each time point, with intraobserver analysis conducted in a random sample of 20 women scanned 3 months following delivery.

RESULTS

One hundred and sixty-nine antenatal scans, 83 early postpartum scans and 75 scans at 3 months postpartum were performed. The intra- and interobserver ICCs, respectively, were 0.95 and 0.86-0.88 for hiatal area, 0.90 and 0.16-0.74 for hiatal transverse diameter, 0.91 and 0.73-0.80 for hiatal anteroposterior diameter, 0.50 and 0.32-0.52 for LAM thickness at the '9 o'clock position' and 0.55 and 0.33-0.45 for LAM thickness at the '3 o'clock position'. Both intra- and interobserver analysis revealed acceptable LOAs for hiatal measurements, but the LOAs were wide for thickness measurements. The correlation of LAM avulsion score was excellent on intra- and interobserver analysis. Antenatal mean ± SD LUGs were 18.8 ± 2.4 mm and 19.2 ± 2.3 mm on right and left sides, respectively; the intraobserver ICC was 0.82-0.91 but LOAs were wide, while interobserver ICC was 0.13-0.68 and also had wide LOAs.

CONCLUSIONS

3D-EVUS is a reliable tool for the assessment of hiatal measurements and LAM avulsion in women during pregnancy and after delivery, but performs less well for measurements of LAM thickness and LUG. EVUS can therefore be used in research studies involving childbirth and recurrent prolapse.

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.

Evaluation of vaginal cysts and masses by 3-dimensional endovaginal and endoanal sonography

The purpose of this pictorial essay is to describe the utility of 3-dimensional endovaginal and endoanal sonography in the assessment of vulvovaginal cysts and masses. It is accepted that compared with transabdominal pelvic sonography, transvaginal end-fire sonography provides improved resolution for visualization of female reproductive organs with fewer artifacts. To visualize the structures that are located in or lateral to the vaginal canal, side-fire 3-dimensional endovaginal or endoanal sonography can be used. This special technique has the advantage of maintaining the spatial anatomic relationship of any abnormality in the vagina.

Transvaginal sling release with intraoperative ultrasound guidance

INTRODUCTION

Visualization of a midurethral sling may be challenging intraoperatively, especially if the sling is deep, well healed, not in the usual location, or made of materials that are not colored.

CASE

We present the case of a 71-year-old woman presenting with a history of incomplete bladder emptying and debilitating voiding dysfunction documented by uroflowmetry and postvoid residual after a tension-free vaginal tape placement. Medications in addition to attempts to dilate her urethra failed to provide her with adequate relief. Intraoperative 3-dimensional ultrasound guidance was used to transect the sling that was otherwise unable to be localized with examination alone.

CONCLUSIONS

Surgical transection of a tension-free vaginal tape can be safely performed under the guidance of ultrasound. At her 12-month follow-up visit, the patient did not have urinary incontinence or voiding dysfunction.

Does age affect visualization of the levator ani in nulliparous women?

INTRODUCTION AND HYPOTHESIS

Our aim was to assess whether differences in the ages of nulliparous women affect: (1) interobserver reliability, and (2) visualization of the levator ani (LA) muscle subdivisions in nulliparous women using 3D endovaginal ultrasound (3D-EVUS).

METHODS

This was a cross-sectional study. Community-dwelling nulliparous women ages 21-70 years were recruited. Participants underwent a standard examination and a 3D-EVUS. LA subdivisions of interest included the puboperinealis, puboanalis, pubococcygeus, puborectalis, and ileococcygeus muscles. Each ultrasound (US) volume was scored using a validated scale and assessed by two observers. Defect severity was scored for each muscle from 0 (no defect) to 6 (complete muscle loss). A summed score of the two sides was grouped as normal (0), minor (1-3), or major (4-6). Bias was examined using Bland-Altman plots. Intraclass coefficients were calculated to report agreement of total scores. Spearman's rank correlation was used to evaluate the association between age and LA scores.

RESULTS

Eighty nulliparous women were evaluated. Exact agreement for bilateral scoring of each LA subdivision ranged from 82 % to 84 %. Bilateral scoring of the puboperinealis, puborectalis, and ileococcygeus showed moderate to substantial agreement. Bilateral scores of the puboperinealis demonstrated substantial agreement between observers, with an ICC of 0.8 and a mean difference of -0.2 using the Bland-Altman analysis. When women were analyzed by age decade, reader agreement was overall good to excellent. There was no significant correlation between increasing age and total LA muscle scores (r = 0.179, p = 0.113).

CONCLUSIONS

Interobserver reliability or visualization of the LA muscle in nulliparous women was not affected by a woman's age.

The determinants of minimal levator hiatus and their relationship to the puborectalis muscle and the levator plate

OBJECTIVE

To determine the muscles comprising the minimal levator hiatus.

DESIGN

Cross-sectional study.

SETTING

The University of Oklahoma Health Sciences Center, USA.

POPULATION

Eight female fresh frozen pelves and 80 nulliparouswomen.

METHODS

Three-dimensional endovaginal ultrasound was performed in eight fresh frozen female pelves. The structures of the levator hiatus were tagged with needles and the cadavers were dissected to identify the tagged structures. A group of 80 nullipara underwent 3D endovaginal ultrasound, and the minimal levator hiatus area, puborectalis area, and anorectal angle were assessed, and normal values were obtained.

MAIN OUTCOME MEASURES

Anatomic borders of minimal levator hiatus and normality in pelvic floor measurements.

RESULTS

The pubococcygeus forms the inner lateral border and anterior attachment of the minimal levator hiatus to the pubic bone. The puboanalis fibres are immediately lateral to pubococcygeus attachments. There are variable contributions of the puborectalis fibres lateral to the puboanalis attachment. The posterior border of the minimal levator hiatus is formed by the levator plate. Eighty community-dwelling nulliparous women underwent 3D endovaginal ultrasound. The median age was 47 years (range 22-70 years). The mean of minimal levator hiatus and puborectalis hiatus areas were 13.4 cm(2) (±1.89 cm(2) SD) and 14.8 cm(2) (±2.16 cm(2) SD). The mean anorectal and levator plate descent angles were 156° (±10.04° SD) and 15.9° (±8.28° SD).

CONCLUSION

Anterior and lateral borders of the minimal levator hiatus are formed mostly by pubococcygeus. The puborectalis, pubococcygeus, and iliococcygeus form the bulk of the levator plate.