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

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

Twisted orientation of the muscle bundles in the levator ani functional parts in women: Implications for pelvic floor support mechanism

This study presents a comprehensive investigation of the anatomical features of the levator ani muscle. The levator ani is a critical component of the pelvic floor; however, its intricate anatomy and functionality are poorly understood. Understanding the precise anatomy of the levator ani is crucial for the accurate diagnosis and effective treatment of pelvic floor disorders. Previous studies have been limited by the lack of comprehensive three-dimensional analyses; to overcome this limitation, we analysed the levator ani muscle using a novel 3D digitised muscle-mapping approach based on layer-by-layer dissection. From this examination, we determined that the levator ani consists of overlapping muscle bundles with varying orientations, particularly in the anteroinferior portion. Our findings revealed distinct muscle bundles directly attached to the rectum (LA-re) and twisted muscle slings surrounding the anterior (LA-a) and posterior (LA-p) aspects of the rectum, which are considered functional parts of the levator ani. These results suggest that these specific muscle bundles of the levator ani are primarily responsible for functional performance. The levator ani plays a crucial role in rectal elevation, lifting the centre of the perineum and narrowing the levator hiatus. The comprehensive anatomical information provided by our study will enhance diagnosis accuracy and facilitate the development of targeted treatment strategies for pelvic floor disorders in clinical practice.

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

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

Unilateral levator avulsion increases the risk of de novo stress urinary incontinence after cystocele repair

INTRODUCTION

Patients without concurrent baseline stress urinary incontinence (SUI) can develop de novo SUI after transvaginal mesh surgery (TVM) for cystocele repair. Surgeons should be aware of de novo SUI risk factors after TVM.

METHODS

A total of 1124 women who were underwent TVM surgeries were recruited and assessed for eligibility from January 1, 2012 to April 30, 2021. All data related to patients and surgeries was collected, which included general conditions, clinical examination, surgery records, and follow-up results. Patients were divided into three groups according to follow-up results and data were compared with each group. The relative risk (RR) of de novo SUI with levator avulsion was also calculated.

RESULTS

Three hundred thirty-six patients were included in this study. They were divided into no complication group (n = 249), de novo SUI group (n = 68), and other complications group (n = 19). It seemed elder or obese women had a higher risk of de novo SUI after TVM (p < 0.05). In de novo SUI group, incidence of levator avulsion before surgery were higher than the other two groups (p = 0.001). TVM can significantly change a prolapse to point Aa and Ba on POP-Q quantification system (p < 0.05). RR ratios of de novo SUI with unilateral avulsion group is 2.60 (95% confidence interval [CI] 1.39-4.87), and 2.58 (95%CI 0.82-8.15) for bilateral group.

CONCLUSION

Unilateral levator avulsion, instead of bilateral levator avulsion, is a risk factor of de novo SUI after cystocele repair surgery.

Ultrasound examination of the pelvic floor during active labor: A longitudinal cohort study

INTRODUCTION

There is limited evidence about changes in the pelvic floor during active labor. We aimed to investigate changes in hiatal dimensions during the active first stage of labor and associations with fetal descent and head position.

MATERIAL AND METHODS

We conducted a longitudinal, prospective cohort study at the National University Hospital of Iceland, from 2016 to 2018. Nulliparous women with spontaneous onset of labor, a single fetus in cephalic presentation, and gestational age ≥37 weeks were eligible. Fetal position was assessed with transabdominal ultrasound and fetal descent was measured with transperineal ultrasound. Three-dimensional volumes were acquired from transperineal scanning at the start of the active phase of labor and in late first stage or early second stage. The largest transverse hiatal diameter was measured in the plane of minimal hiatal dimensions. The levator urethral gap was measured as the distance between the center of the urethra and the levator insertion using tomographic ultrasound imaging. Measurements of the levator urethral gap were made in the plane of minimal hiatal dimensions and 2.5 and 5 mm cranial to this.

RESULTS

The final study population comprised 78 women. The mean transverse hiatal diameter increased 12.4% between the two examinations, from 39.4 ± 4.1 mm (±standard deviation) at the first examination to 44.3 ± 5.8 mm at the last examination (p < 0.01). We found a moderate correlation between the transverse hiatal diameter and fetal station at the last examination (r = 0.44, r2  = 0.19; p < 0.01; regression equation y = 2.71 + 0.014x), and a weak correlation between the change in transverse hiatal diameter and change in fetal station (r = 0.29; r2  = 0.08; p = 0.01; regression equation y = 0.24 + 0.012x). Levator urethral gap increased significantly in all three planes on both the left and right sides. Head position was not associated with hiatal measurements after adjusting for fetal station.

CONCLUSIONS

We found a significant, but only modest, increase of the hiatal dimensions during the first stage of labor. The risk of levator ani trauma will therefore be low during this stage. The change in transverse hiatal diameter was associated with fetal descent but not with head position.

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.

The key role of levator ani thickness for early urinary continence recovery in patients undergoing robot-assisted radical prostatectomy: A multi-institutional study

BACKGROUND

Urinary continence (UC) recovery dramatically affects quality of life after robot-assisted radical prostatectomy (RARP). Membranous urethral length (MUL) has been the most studied anatomical variable associated with UC recovery.

OBJECTIVE

To investigate whether levator ani thickness (LAT), assessed with multi-parametric magnetic resonance imaging (mpMRI), correlates with UC recovery after RARP.

DESIGN, SETTING, AND PARTICIPANTS

The study included 209 patients treated with RARP by expert surgeons with extensive robotic experience from 2017 to 2019. All patients had complete, clinical, mpMRI, pathological, and postoperative data including pelvic floor muscle training (PFMT) protocols.

INTERVENTION

After a radiologist-specific training, two urologists independently examined the files, blinded to clinical and pathological findings as well as to postoperative continence status.

OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS

On mpMRI, LAT, bladder neck (BN) shape, MUL, and apex overlapping (AO) were measured. UC recovery was defined as use of 0 or 1 safety pad at follow-up. Multivariable models were used to assess the association between variables and UC recovery.

RESULTS AND LIMITATIONS

Overall, 173 (82.8%) patients were continent after a median follow-up of 23 months (interquartile range [IQR]: 17-28). Of these, 98 (46.9%) recovered within 3 months after surgery, 42 (20.1%) from 3 to 6 months, and 33 (15.8%) from 6 months onwards. A significant higher rate of patients with LAT > 10 mm (88.1 vs.75.8%; p = 0.03) experienced UC recovery, compared to those with LAT < 10 mm. This difference was observed in the first 3 months after surgery. At multivariable analysis, LAT (odds ratio [OR]: 1.18, 95% confidence interval [CI]: 1.02-1.37; p = 0.02), Preoperative ICIQ score (OR: 0.91, 95% CI: 0.82-0.98, p = 0.03) and PFMT (OR: 1.98, 95% CI: 1.01-3.93; p = 0.04) independently predict higher UC recovery within 3 months, after accounting for age, BMI, preoperative PSA, D'Amico risk group, MUL, BN shape and AO.

CONCLUSIONS

LAT greater than 1 cm was associated with greater UC recovery. Specifically, LAT greater than 1 cm seems to be associated with higher UC rate at 3 months after RARP, compared to those with LAT < 1 cm.

PATIENT SUMMARY

Magnetic resonance features can help in predicting the risk of incontinence after robot-assisted radical prostatectomy and should be taken into account when counseling patients before surgery.

Postpartum perineal muscle sonogram in Madura beef cow

Background and Aim:

Ultrasonography (USG) is useful for non-invasively identifying changes that occur in soft tissue architecture. The objective of this research was to demonstrate postpartum (PP) uterine involution through the changes of perineal muscle intensity and thickness in Madura beef cow by ultrasonography.

Materials and Methods:

Madura’s breed cows used in the research consist of eight non-pregnant (NP) cows and three PP cow. The transrectal and transperineal USG imaging of NP cows was performed on days 1, 33, and 65. USG imaging of PP cows was performed every day starting from day 1 (24 h after parturition) until day 21 PP. Transrectal USG of the reproductive tract was performed for the cervix, corpus uteri, and cornua uteri. USG was performed transcutaneously over the perineal area for coccygeus and levator ani muscles at the longitudinal and transverse angles. Reproductive tract diameter and perineal muscle intensity and thickness were measured with ultrasound imaging.

Results:

The analysis of the sonogram of PP cows showed that the diameter of the cervix, corpus uteri, and cornua uteri decreased within 21 days PP. The transverse view of the coccygeus muscle of PP cows showed decreased muscle intensity and thickness. On the other hand, the longitudinal view showed increased coccygeus muscle intensity and thickness. The transverse view of the coccygeus muscle of NP cows showed increased muscle intensity, while muscle thickness was reduced. Sonogram analysis of the levator ani muscle of PP cows showed decreased muscle intensity with increasing muscle thickness. However, imaging of the levator ani muscle of NP cows showed a decrease in both intensity and muscle thickness. There was a significant difference in the mean value intensity of the scanning view analysis results of the levator ani muscle of the PP cow (523.6 AU increased to 672.1 AU) and the NP cow (515.9 AU decreased to 465.4 AU). Furthermore, there was a significant difference (p<0.05) in the mean value thickness of both scanning view analyses of the coccygeus and levator ani muscles of PP cows (5.8 mm increased to 6.5 mm and 3.8 mm increased to 4.8 mm, respectively) and NP cows (8.8 mm increased to 9.1 mm and 5.9 mm decreased to 4.9 mm, respectively).

Conclusion:

We found that the perineal muscles, namely, the levator ani muscle and coccygeus muscle, change in size, and intensity during uterine involution as demonstrated on Madura beef cow.

The Expression of Hormone Receptors as a Gateway toward Understanding Endocrine Actions in Female Pelvic Floor Muscles

OBJECTIVE

To provide an overview of the hormone actions and receptors expressed in the female pelvic floor muscles, relevant for understanding the pelvic floor disorders.

METHODS

We performed a literature review focused on the expression of hormone receptors mainly in the pelvic floor muscles of women and female rats and rabbits.

RESULTS

The impairment of the pelvic floor muscles can lead to the onset of pelvic floor dysfunctions, including stress urinary incontinence in women. Hormone milieu is associated with the structure and function alterations of pelvic floor muscles, a notion supported by the fact that these muscles express different hormone receptors. Nuclear receptors, such as steroid receptors, are up till now the most investigated. The present review accounts for the limited studies conducted to elucidate the expression of hormone receptors in pelvic floor muscles in females.

CONCLUSION

Hormone receptor expression is the cornerstone in some hormone-based therapies, which require further detailed studies on the distribution of receptors in particular pelvic floor muscles, as well as their association with muscle effectors, involved in the alterations relevant for understanding pelvic floor disorders.

Approach to a woman with urinary incontinence

Urinary incontinence is a bothersome situation to the ailing woman. Many times, the woman does not come to medicos due to shyness, and if she comes also she does not reveal all the information. Hence, a sympathetic and structured approach will help to provide judicious management to these women. When a woman with the complaint of urinary incontinence approaches us, we should collect maximum information with the help of structured questionnaire and protocol. Structured questionnaire provides most of the information pertinent to the urinary incontinence. Associated medical disorders are also looked for. Past obstetrical performance can have implication on this ailment. Pelvic organ prolapse, mass lower abdominal, etc., also can lead to urinary incontinence. Adverse effect of some medicines causes urinary incontinence. During general physical examination, attention has to be paid toward body mass index, joint hypermobility, spine, etc. During local examination, stress test, Bonney test, Q-tip test, etc., may help to some extent. The levator ani muscle is assessed of its strength. Neurological evaluation is to be done for all the patients with urinary incontinence. Urinary culture and sensitivity are routinely done. Once urinary infection is ruled out, then the woman is subjected to frequency/volume diary, ultrasonography, urodynamic study, cystoscopy, etc., depending on the necessity. A systematic approach to urinary incontinence will provide the best comfort to these ailing women.

Self-Perceived Improvement in Bladder Health After Viewing a Novel Tutorial on Knack Use: A Randomized Controlled Trial Pilot Study

Purpose: To test a novel bladder health tutorial on use of the Knack for overcoming bladder control challenges. The Knack-tutorial is a self-administered vignette-based instructional program on preempting bladder challenges in daily life (urgency, stress-leakage, or urge-leakage) through anticipatory, well-timed pelvic floor muscle contraction at the moment of challenge. Materials and Methods: This is a randomized controlled trial pilot test of 108 women with stress or mixed urinary incontinence. The Knack-tutorial group saw a 15-minute slide show with 10 vignettes portraying use of the Knack in daily life. The slide show format used inserted narrated videos, dubbed and animation enhanced pictures and cartoons, and automatic slide advancement. A control group saw a similarly constructed slide show on incorporating good diet/exercise habits. Outcomes were self-perceived improvement (yes/no, and as 0%-100%) 1 month after viewing the tutorial. Results: We enrolled 123 women, randomizing 64 to Knack-tutorial group and 59 to diet/exercise tutorial group. Eleven and one participant, respectively, did not return. Three did not fill out the self-perceived improvement report. Significant improvement was reported by 71% in the Knack-tutorial group compared to 25% in the diet/exercise group (p < 0.001). Self-perceived improvement was 21%-22% higher (Model I Est: 21.01, SE: 4.25, p < 0.001) in the Knack-tutorial group. Conclusions: An electronic tutorial viewed independent of a health care provider with vignettes showing Knack application to manage the everyday bladder challenges women face shows benefit of a magnitude that warrants more widespread use and rigorous testing. A professional remake of the intervention is now available (www.myconfidentbladder.com).

Smooth muscle of the male pelvic floor: An anatomic study

Knowledge of the anatomy of the male pelvic floor is important to avoid damaging the pelvic floor muscles during surgery. We set out to explore the structure and innervation of the smooth muscle (SM) of the whole pelvic floor using male fetuses. We removed en-bloc the entire pelvis of three male fetuses. The specimens were serially sectioned before being stained with Masson's trichrome and hematoxylin and eosin, and immunostained for SMs, and somatic, adrenergic, sensory and nitrergic nerve fibers. Slides were digitized for three-dimensional reconstruction. We individualized a middle compartment that contains SM cells. This compartment is in close relation with the levator ani muscle (LAM), rectum, and urethra. We describe a posterior part of the middle compartment posterior to the rectal wall and an anterior part anterior to the rectal wall. The anterior part is split into (1) a centro-levator area of SM cells localized between the right and left LAM, (2) an endo-levator area that upholsters the internal aspect of the LAM, and (3) an infra-levator area below the LAM. All these areas are innervated by autonomic nerves coming from the inferior hypogastric plexus. The core and the infra-levator area receive the cavernous nerve and nerves supplying the urethra. We thus demonstrate that these muscular structures are smooth and under autonomic influence. These findings are relevant for the pelvic surgeon, and especially the urologist, during radical prostatectomy, abdominoperineal resection and intersphincteric resection. Clin. Anat., 2019. © 2019 Wiley Periodicals, Inc.

Endometriosis infiltrating the pelvic floor muscles with histopathological correlation-A case report

We report the case of a 29-year-old woman with deep infiltrating endometriosis who underwent robotic nerve-sparing surgery for resection of all visible lesions infiltrating pelvic and extrapelvic sites. Painful symptoms included severe dysmenorrhea, menstrual dyschezia and stranguria, with no improvement in response to hormonal treatment. The location on physical examination of a painful retrocervical nodule was identified by magnetic resonance imaging to be infiltrating the right parametrium/paracervix. During surgery, this nodule was recognized as an important retrocervical/rectovaginal lesion infiltrating the pelvic floor (i.e. levator ani and coccygeus), and was histopathologically confirmed as endometriosis infiltrating the skeletal pelvic floor muscles. A Pubmed search of the MEDLINE database in March (2019) found no publication reporting histopathologic confirmation of endometriosis infiltrating the pelvic floor muscles.

Does levator ani hiatal area configuration affect pelvic organ prolapse?

OBJECTIVE

Levator ani trauma and hiatal overdistension have been shown to be associated with female pelvic organ prolapse (POP); however, the role of the shape of the levator hiatus in POP has not been examined to date. The aim of this study was to investigate the association between the configuration of the levator ani hiatus and POP.

METHODS

This was a retrospective study of 547 women who attended a tertiary urogynecological center for symptoms of pelvic floor and lower urinary tract dysfunction between October 2014 and August 2016. All women underwent a standardized interview and prolapse assessment using the International Continence Society (ICS) Pelvic Organ Prolapse Quantification (POP-Q) method and four-dimensional translabial ultrasound (TLUS). Measurements of the hiatal anteroposterior diameter (APD), coronal diameter (CD) and hiatal area (HA), at rest and on maximal Valsalva maneuver, and those of organ descent were performed offline at a later date by an investigator blinded to all other data. Hiatal configuration was defined as the ratio APD/CD. Associations between HA and HA adjusted by APD/CD at rest and on maximal Valsalva and symptoms and signs of prolapse were analyzed statistically using logistic regression modelling.

RESULTS

The mean age of the women was 54 ± 13.6 (range, 16-89) years. Of the 547 women included, 241 (44%) presented with prolapse symptoms. Clinically significant POP was detected in 406 (74%) patients and significant prolapse on TLUS was detected in 331 (61%). Hiatal ballooning was observed in 310 (57%) women and this was strongly associated with signs and symptoms of POP. HA at rest and on Valsalva was associated with significant POP both on clinical examination and on TLUS. Adjusted odds ratios for hiatal shape showed no effect of the hiatal configuration on the association between HA and POP.

CONCLUSION

Hiatal shape does not seem to influence the association between HA and symptoms and signs of prolapse. Copyright © 2018 ISUOG. Published by John Wiley & Sons Ltd.

Task-specific differences in respiration-related activation of deep and superficial pelvic floor muscles

The female pelvic floor muscles (PFM) are arranged in distinct superficial and deep layers that function to support the pelvic/abdominal organs and maintain continence, but with some potential differences in function. Although general recordings of PFM activity show amplitude modulation in conjunction with fluctuation in intra-abdominal pressure such as that associated with respiration, it is unclear whether the activities of the two PFM layers modulate in a similar manner. This study aimed to investigate the activation of the deep and superficial PFM during a range of respiratory tasks in different postures. Twelve women without pelvic floor dysfunction participated. A custom-built surface electromyography (EMG) electrode was used to record the activation of the superficial and deep PFM during quiet breathing, breathing with increased dead space, coughing, and maximal and submaximal inspiratory and expiratory efforts. As breathing demand increased, the deep PFM layer EMG had greater coherence with respiratory airflow at the frequency of respiration than the superficial PFM (P = 0.038). During cough, the superficial PFM activated earlier than the deep PFM in the sitting position (P = 0.043). In contrast, during maximal and submaximal inspiratory and expiratory efforts, the superficial PFM EMG was greater than that for the deep PFM (P = 0.011). These data show that both layers of PFM are activated during both inspiration and expiration, but with a bias to greater activation in expiratory tasks/phases. Activation of the deep and superficial PFM layers differed in most of the respiratory tasks, but there was no consistent bias to one muscle layer. NEW & NOTEWORTHY Although pelvic floor muscles are generally considered as a single entity, deep and superficial layers have different anatomies and biomechanics. Here we show task-specific differences in recruitment between layers during respiratory tasks in women. The deep layer was more tightly modulated with respiration than the superficial layer, but activation of the superficial layer was greater during maximal/submaximal occluded respiratory efforts and earlier during cough. These data highlight tightly coordinated recruitment of discrete pelvic floor muscles for respiration.

Impact of levator muscle avulsions on Manchester procedure outcomes in pelvic organ prolapse surgery

INTRODUCTION

Levator ani muscle avulsions potentially increase recurrence after anterior colporrhaphies. We aimed at evaluating the impact of avulsions on anatomical and patient-reported outcomes 1 year after the Manchester procedure for primary anterior compartment pelvic organ prolapse.

MATERIAL AND METHODS

Prospective cohort study of 189 women undergoing the Manchester procedure between October 2014 and January 2017. Avulsions were diagnosed by transperineal ultrasound. Women with and without avulsions were compared for 1-year postoperative outcomes; Pelvic Organ Prolapse Quantification measurements, subjective satisfaction (1-worse to 4-cured), failure (new prolapse treatment), response to validated questionnaires on pelvic floor distress and sexual function, and a composite outcome (subjectively cured and optimal anterior compartment outcome (stage 0-I)). Optimal mid-compartment outcome was defined as cervix ≥5 cm above the hymen. Factors potentially associated with poor anatomical outcomes (anterior compartment stage ≥II) or pelvic floor distress were analyzed using regression analyses.

RESULTS

Fewer women with avulsions (present in 50.8%) obtained optimal mid-compartment outcomes (88.2% vs 77.1%; P = 0.05). The groups were otherwise similar in terms of mid-compartment reduction, anterior compartment results, failure rate, subjective satisfaction, pelvic floor/sexual symptoms, and combined optimal subjective and anatomical outcome. Only preoperative anterior compartment stage ≥III was associated with poor anatomical outcome (P < 0.01). A high preoperative symptom score was associated with a high postoperative symptom score (P < 0.001).

CONCLUSIONS

Although fewer women with avulsions obtained optimal mid-compartment results, avulsions had no impact on other anatomical or symptomatic outcomes 1 year after the Manchester procedure for primary anterior compartment prolapse.

Association between pelvic floor muscle trauma and contraction in parous women from a general population

OBJECTIVE

To study possible associations between pelvic floor muscle contraction, levator ani muscle (LAM) trauma and/or pelvic organ prolapse (POP) ≥ Stage 2 in parous women recruited from a general population.

METHODS

This was a secondary analysis of data from a cross-sectional study of 608 parous women from a general population examined using the POP quantification system (POP-Q) and three-dimensional/four-dimensional transperineal ultrasound for identification of LAM macrotrauma (avulsion) and microtrauma (distension of levator hiatal area > 75^th percentile on Valsalva maneuver). Muscle contraction was assessed using the modified Oxford scale (MOS), perineometry and ultrasound measurement of proportional change of anteroposterior hiatal diameter and levator hiatal area at rest and on pelvic floor muscle contraction. The Mann-Whitney U-test was used to study associations between pelvic floor muscle contraction, LAM trauma and POP.

RESULTS

Women with macrotrauma (n = 113) had significantly weaker median pelvic floor muscle contraction, as measured using MOS and perineometry, than did women with an intact LAM (n = 493) (contraction strength was 1.5 (range, 0.0-5.0) vs 3.5 (range, 0.0-5.0) on MOS, and vaginal squeeze pressure was 15.0 (range, 0.0-78.0) cmH₂ O vs 28.0 (range, 0.0-129.0) cmH₂ O on perineometry; P < 0.001). This was also demonstrated by ultrasound measurement, with a proportional change in hiatal area of 19.9% (range, 4.1-48.0%) vs 34.0% (range, 0.0-64.0%) (P < 0.001) and proportional change in anteroposterior diameter of 16.2% (range, -5.7 to 42.6%) vs 26.0% (range, -3.4 to 49.4%) (P < 0.001). No statistically significant difference between women with (n = 65), and those without (n = 378), microtrauma was found after excluding women with macrotrauma. Women with POP had weaker muscle contraction than those without; in those with POP-Q ≥ 2 (n = 275) compared with those with POP-Q < 2 (n = 333), muscle contraction strength was 3.0 (range, 0.0-5.0) vs 3.5 (range, 0.0-5.0) on MOS, vaginal squeeze pressure was 21.0 (range, 0.0-98.0) cmH₂ O vs 28.0 (range, 3.0-129.0) cmH₂ O on perineometry, proportional change in hiatal area was 29.6% (range, 0.0-60.9%) vs 33.8% (range, 0.0-64.4%) and proportional change in anteroposterior diameter was 22.8% (range, -5.7 to 49.4%) vs 25.7% (range, -3.4 to 49.4%) (P < 0.001 for all).

CONCLUSIONS

LAM macrotrauma was associated with weaker pelvic floor muscle contraction measured using palpation, perineometry and ultrasound. Women with POP had weaker contraction than did women without POP. Copyright © 2018 ISUOG. Published by John Wiley & Sons Ltd.

Association of levator injury and urogynecological complaints in women after their first vaginal birth with and without mediolateral episiotomy

BACKGROUND

Pelvic organ prolapse is a common health problem in women and has a negative influence on quality of life. A major cause of pelvic organ prolapse is levator injury.

OBJECTIVE

The objective of the study was to evaluate the association of mediolateral episiotomy with levator injury (levator avulsion, ballooning, or combined) and urogynecological complaints.

STUDY DESIGN

A prospective observational cohort study was performed in 204 primiparous women with a spontaneous vaginal delivery without anal sphincter tear in a general hospital between 2012 and 2015. One hundred three of these women had had a mediolateral episiotomy. Validated urogynecological questionnaires and transperineal 3-dimensional/4-dimensional ultrasound were completed after delivery. Outcome measures were levator avulsion, ballooning (hiatal area of more than 25 cm²), and urogynecological questionnaire scores. Statistical analysis was performed using univariate and multiple logistic regression analysis.

RESULTS

The median time at investigation after vaginal delivery was 13 months (range 6-33). Levator injury (avulsion, ballooning, or combined) was identified in 35 of the 103 women who had undergone mediolateral episiotomy (40.0%) and 33 of the 101 women without episiotomy (32.7%) (P = .69). No differences were found in the incidence of levator avulsion 27 (26.7%) vs 23 (22.8%) (P = .53) or in levator ballooning (20 [19.4%] vs 23 [22.8%] (P = .58) between both groups. There was an association between longer duration of the second stage of labor and the incidence of levator avulsion (odds ratio, 1.24 [95% confidence interval, 1.01-1.52]). Nonocciput anterior fetal position increased the risk of levator ballooning and levator injury (odds ratio, 10.19 [95% confidence interval, 1.89-54.91] and odds ratio, 12.16 [95% confidence interval, 1.41-104.38], respectively). No differences in urogynecological complaints were found.

CONCLUSION

Mediolateral episiotomy is not associated with the occurrence of levator injury or urogynecological complaints in women with a spontaneous vaginal delivery who did not obtain an anal sphincter injury. Levator injury was associated with a prolonged second stage of labor and a nonocciput anterior fetal position.

A cadaveric study

INTRODUCTION

The sonographic appearance of a levator muscle "avulsion" representing the literal detachment of the pubovisceral muscle (PVM) enthesis has been contested. The nature of the levator ani "avulsion" is still not fully understood. It is known, that the tensile strength of a tendon is dependent on collagen with increased synthesis of collagen occurring in tissue with increased mechanical load levels. This study aims to perform a quantitative histological evaluation of the PVM enthesis with or without the imaging finding of levator ani "avulsion" to determine if there is a difference in the proportion of muscle and collagen.

METHOD

Three-dimensional translabial ultrasound for PVM "avulsion" was performed on cadavers using a GE Voluson I with a 5-9 MHz electronic probe. Cadavers were meticulously dissected to identify the presence or absence of an anatomical avulsion. The PVM enthesis was excised for further histopathological processing and treated with three different colorations. Quantitative analysis using ImageJ software was conducted to compare tissue composition in samples with or without sonographic "avulsion." All stages were performed by two separate investigators blinded to each other's results. The results were analyzed using SPSS v24, IBM.

RESULTS

Twenty-three PVM enthesis with histological staining were procured. Ultrasonographic "avulsions" were seen in 5/23 PVM enthesis. No anatomical avulsions were seen. There was no difference in the overall muscle or collagen content (Kruskal-Wallis, P = 0.864). The mean organized skeletal muscle content was 23% in the sonographic "avulsion" group versus 62% in the no "avulsion" group (Kruskall-Walis, P = 0.02). "Avulsions" were associated with a disorganized appearance at histology.

CONCLUSION

The tissue composition relating to the proportion of muscle and collagen was not significantly different in specimens with or without sonographic "avulsions." However, morphological differences were observed in the organization of the muscle fibres, which requires further evaluation.

Is pelvic organ support different between young nulliparous African and Caucasian women?

OBJECTIVE

There seems to be substantial variation in the prevalence of pelvic floor disorders between different ethnic groups. This may be due partially to differences in pelvic floor structure and functional anatomy. To date, data on this issue are sparse. The aim of this study was to compare hiatal dimensions, pelvic organ descent and levator biometry in young, healthy nulliparous Caucasian and African women.

METHODS

Healthy nulliparous non-pregnant volunteers attending a local nursing school in Uganda were invited to participate in this study during two fistula camps. All volunteers underwent a simple physician-administered questionnaire and a four-dimensional translabial ultrasound examination. Offline analysis was performed to assess hiatal dimensions, pelvic organ descent, levator muscle thickness and area. To compare findings with those obtained in nulliparous non-pregnant Caucasians, we retrieved the three-dimensional/four-dimensional ultrasound volume datasets of a previously published study.

RESULTS

The dataset of 76 Ugandan and 49 Caucasian women was analyzed. The two groups were not matched but they were comparable in age and body mass index. All measurements of hiatal dimensions and pelvic organ descent were significantly higher among the Ugandans (all P ≤ 0.01); however, muscle thickness and area were not significantly different between the two groups.

CONCLUSIONS

Substantial differences between Caucasian and Ugandan non-pregnant nulliparae were identified in this study comparing functional pelvic floor anatomy. It appears likely that these differences in functional anatomy are at least partly genetic in nature. Copyright © 2015 ISUOG. Published by John Wiley & Sons Ltd.

Paravaginal defect: A new classification of fascial and muscle tears in the paravaginal region

The lateral support of the vaginal wall depends on the integrity of the paravaginal section of the visceral pelvic fascia, levator ani, and their connection. Various defects of the muscle and fascia can result in identical clinical findings-ie, the descent of the lateral vaginal sulcus. In this study, we created a realistic scheme for classifying paravaginal defects, based on the complex relationship of the pelvic fascia with the levator ani. Surgical observations, cadaver examinations, and a complex magnetic resonance imaging (MRI)-based 3-dimensional (3D) model were used to analyze the spatial relationships of normal and defective anatomy of the female pelvic floor. Descent of the lateral vaginal sulcus can result from a defect in the paravaginal visceral pelvic fascia, levator ani, or both. The fascial defect can be partial or complete, and the muscle defect can vary in location. A detailed illustrated classification is presented. We present a new model of the pathology that underlies a common clinical finding.

Perineal and vaginal tears are clinical markers for occult levator ani trauma: a retrospective observational study

OBJECTIVES

Levator avulsion has been shown to be associated with anterior and central compartment prolapse and is a risk factor for prolapse recurrence. Diagnosis in the delivery room is usually impossible, as levator avulsion is commonly occult. The objective of this study was to determine if vaginal and major perineal tears are clinical markers of levator trauma as diagnosed by four-dimensional (4D) translabial ultrasound 3-6 months postpartum.

METHODS

This was a retrospective observational study using data obtained in two perinatal trials. A total of 774 women seen, on average, 5 (range, 2.3-22.4) months after their first delivery of a term singleton cephalic baby underwent a standardized interview, clinical assessment and 4D translabial ultrasound examination. Clinical data were obtained from the institutional obstetric database, including information on vaginal and perineal tears. Levator avulsion was diagnosed using tomographic ultrasound, with operators blinded to the clinical data.

RESULTS

Both third- and fourth-degree perineal tears and vaginal sidewall tears were independently associated with levator avulsion (P = 0.004 and P = 0.012, respectively). The odds ratio for avulsion in women suffering from such overt trauma was 3.44 (95% CI, 1.47-8.03) for third-/fourth-degree perineal tears and 3.35 (95% CI, 1.30-8.61) for vaginal sidewall tears.

CONCLUSIONS

Vaginal sidewall and third-/fourth-degree perineal tears were found to be independent clinical indicators of an increased risk of levator trauma, as diagnosed by 4D translabial ultrasound 3-6 months postpartum. Such clinical markers may become useful in the identification of women at high risk of levator trauma and future pelvic floor disorders.

Topography and landmarks for the nerve supply to the levator ani and its relevance to pelvic floor pathologies

The aim of this study was to explore the anatomical variations of the nerve to the levator ani (LA) and to relate these findings to LA dysfunction. One hundred fixed human female cadavers were dissected using transabdominal, gluteal, and perineal approaches, resulting in two hundred dissections of the sacral plexus. The pudendal nerve and the sacral nerve roots were traced from their origin at the sacral foramina to their termination. All nerves contributing to the innervation of the LA were considered to be the nerve to the LA. Based on the spinal nerve components, the nerve to the LA was classified into the following categories: 50% (n = 100) originated from S4 and S5 (type I); 19% (n = 38) originated from S5 (type II); 16% (n = 32) originated from S4 (type III); 11% (n = 22) originated from S3 and S4 (type IV); 4% (n = 8) originated from S3, S4, and S5 (type V). Two patterns of nerve termination were observed. In 42% of specimens, the nerve to the LA penetrated the coccygeus muscle and assumed an external position along the inferior surface of the LA muscle. In the remaining 58% of specimens, the nerve crossed the superior surface of the coccygeus muscle and continued along the superior surface of the iliococcygeus muscle. Damage to the nerve to LA has been associated with various pathologies. In order to minimize injuries during surgical procedures, a thorough understanding of the course and variations of the nerve to the LA is extremely important.

Evaluating maternal recovery from labor and delivery: bone and levator ani injuries

OBJECTIVE

We sought to describe occurrence, recovery, and consequences of musculoskeletal (MSK) injuries in women at risk for childbirth-related pelvic floor injury at first vaginal birth.

STUDY DESIGN

Evaluating Maternal Recovery from Labor and Delivery is a longitudinal cohort design study of women recruited early postbirth and followed over time. We report here on 68 women who had birth-related risk factors for levator ani (LA) muscle injury, including long second stage, anal tears, and/or older maternal age, and who were evaluated by MSK magnetic resonance imaging at both 7 weeks and 8 months' postpartum. We categorized magnitude of injury by extent of bone marrow edema, pubic bone fracture, LA muscle edema, and LA muscle tear. We also measured the force of LA muscle contraction, urethral pressure, pelvic organ prolapse, and incontinence.

RESULTS

In this higher-risk sample, 66% (39/59) had pubic bone marrow edema, 29% (17/59) had subcortical fracture, 90% (53/59) had LA muscle edema, and 41% (28/68) had low-grade or greater LA tear 7 weeks' postpartum. The magnitude of LA muscle tear did not substantially change by 8 months' postpartum (P = .86), but LA muscle edema and bone injuries showed total or near total resolution (P < .05). The magnitude of unresolved MSK injuries correlated with magnitude of reduced LA muscle force and posterior vaginal wall descent (P < .05) but not with urethral pressure, volume of demonstrable stress incontinence, or self-report of incontinence severity (P > .05).

CONCLUSION

Pubic bone edema and subcortical fracture and LA muscle injury are common when studied in women with certain risk factors. The bony abnormalities resolve, but levator tear does not, and is associated with levator weakness and posterior-vaginal wall descent.

Evaluation of levator ani with no defect on elastography in women with POP

OBJECTIVE

It is difficult to evaluate the function of levator ani with no defect encountered in routine practice. Elastography is a new adjunct to real-time ultrasound imaging that overlays traditional B-mode imaging with a color graphic representation of tissue elasticity. The aim of this study is to specifically evaluate the function of levator ani with no defect by ES (elastography).

METHODS

This was a prospective, observational study. All patients were examined by MRI and the cases with levator ani defect were excluded. The included cases underwent conventional translabial ultrasound, and then ultrasound ES. A little levator ani were biopsied for immunohistochemistry check in the patients who underwent surgery.

RESULTS

Of the 52 cases with no levator ani defects, 22 had an elastography score of 1, 20 had a score of 2, 8 had a score of 3 and 2 had a score of 4 in levator ani. Cases of ES1 and ES2 were more than ES3 and ES4 (P = 0.004). The immunohistochemistry check indicated that 12 patients who underwent surgery showed weak expression and the other 4 patients showed moderate expression of collagen type I in levator ani, compared with 2 controls showing strong expressions.

CONCLUSIONS

Elastography can assess the change of elasticity function of levator ani though the structure has no defect which was detected by MRI and conventional ultrasound. And probably the change of function of levator ani was earlier than structure abnormity in POP.

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.

Pelvic floor trauma: does the second baby matter?

OBJECTIVE

To ascertain the effect of a second delivery on pelvic floor anatomy.

METHODS

This was a retrospective analysis of data obtained in two perinatal imaging studies. Women were invited for antenatal and two postnatal appointments. All had answered a standardized questionnaire and undergone a clinical examination and translabial four-dimensional ultrasound. Ultrasound volumes were acquired at rest, on Valsalva maneuver and on pelvic floor muscle contraction, and analyzed by postprocessing on a PC. Avulsion was diagnosed on tomographic ultrasound imaging. This study reports data obtained in those women who delivered a second child between the first and second postnatal assessments.

RESULTS

Of 715 participants, 94 reported a second birth at their second postnatal appointment on average 2.7 years after their first birth; 65 had a vaginal delivery and 29 a Cesarean section. There were nine attempts at vaginal birth after Cesarean section (VBAC), of which six were successful. When we analyzed the ultrasound findings before and after a second delivery, there was no significant change observed in bladder-neck descent, cystocele descent and hiatal area on Valsalva. Delivery mode of the second birth seemed to have little effect on changes observed between follow-ups, although there was a trend towards increased bladder-neck descent in women after vaginal delivery. On reviewing patients diagnosed with avulsion at their 2-3-year visit and comparing them with findings at the first follow-up visit, we found identical (normal) findings in 87 cases. In five there was an unchanged avulsion. In one case, findings had improved from complete to partial avulsion. There was one new avulsion, in a patient who had delivered her first baby by emergency Cesarean section and her second by vacuum delivery.

CONCLUSIONS

A second pregnancy and delivery do not seem to have a major effect on bladder support and/or levator function. However, we documented a case of major levator trauma after VBAC. The issue of pelvic floor trauma after VBAC may have to be investigated further.

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.

How common is pelvic floor muscle atrophy after vaginal childbirth?

OBJECTIVE

To determine if there is evidence of levator ani atrophy in primiparous women.

METHODS

This was a prospective observational cohort study of 202 primiparous women recruited between November 2006 and March 2008. Translabial ultrasound volumes were obtained at 36-38 weeks' gestation and at a mean of 4.5 months postpartum. Peripartum changes in bladder neck elevation and reduction of anteroposterior hiatal diameter on pelvic floor muscle contraction (PFMC) and changes in muscle thickness were analyzed.

RESULTS

Of the 202 participants enrolled, 158 (78%) completed the study. There was a significant reduction in bladder neck elevation (P = 0.001) and change in anteroposterior hiatal diameter (P = 0.03) on PFMC when comparing antenatal and postnatal results, the latter being significantly associated with delivery mode (P = 0.013). No significant changes were detected in muscle thickness (P = 0.76).

CONCLUSIONS

There is a reduction in sonographic measures of pelvic floor function after childbirth, but muscle atrophy is unlikely to be a significant factor.

Anterior compartment mesh: a descriptive study of mesh anchoring failure

OBJECTIVES

To define types of support failure after anterior compartment mesh placement and to investigate any association with predictors of recurrence.

METHODS

This was a retrospective study on patients ≥ 3 months after anterior mesh placement. All patients underwent a standardized interview, clinical examination using the International Continence Society Pelvic Organ Prolapse Quantification system (ICS POP-Q) and three-dimensional/four-dimensional (3D/4D) translabial ultrasound. Mesh failure was defined as recurrence of anterior/central compartment prolapse seen on ultrasound. Failures were classified as anterior, global and apical. Their association with hiatal area on Valsalva maneuver and levator avulsion was tested.

RESULTS

Three hundred and one patients were seen initially, of whom five were excluded because of missing data, leaving 296. Mean follow-up was 1.8 (range, 0.3-5.6) years. Mean age was 65 (range, 32-88) years. One hundred and thirty-nine (47%) women were fitted with a Perigee mesh, 66 (22%) with an Anterior Prolift mesh and 91 (31%) with an Anterior Elevate mesh. Recurrent symptoms (lump/drag) were reported in 65 (22%), a recurrent cystocele was noted in 128 clinically (43%) and in 105 on ultrasound (35%). Avulsion was diagnosed in 117 patients (40%). Mean hiatal area on Valsalva was 33.3 (range, 14.1-60.0) cm2. Mesh failure was diagnosed in 112 patients (38%), comprising global failure in 81 (27%), apical failure in 23 (8%) and anterior failure in eight (3%). Apical and global failures were significantly associated with hiatal area, associations that remained after controlling for potential confounders.

CONCLUSIONS

Mesh failure, i.e. anterior or central compartment recurrent prolapse, was noted in 38% of patients on average 1.8 years after placement of anterior compartment mesh. Global and apical failures together constituted 93% of all mesh failures, both types of failure being significantly associated with hiatal area on Valsalva maneuver.

Can hiatal ballooning be determined by two-dimensional translabial ultrasound?

INTRODUCTION

Imaging of the levator hiatus, the largest potential hernial portal in the human body, requires axial plane imaging by ultrasound or magnetic resonance imaging. The aim of this study is to determine whether 2D translabial ultrasound may identify excessive hiatal distensibility by measuring the anteroposterior (AP) diameter of the hiatus. This may become clinically relevant for risk stratification of women prior to prolapse surgery.

METHODS

This is a retrospective analysis of 577 women seen at a tertiary urogynaecological unit between May 2008 and September 2010. All women underwent a standardised interview, clinical prolapse assessment (ICS POP-Q) and translabial ultrasound. The hiatal AP diameter was measured at rest, on Valsalva and during pelvic floor muscle contraction. All analyses were performed offline, blinded against clinical data.

RESULTS

There was a strong statistical relationship between reported prolapse symptoms/pelvic organ descent and hiatal AP diameter on Valsalva (P < 0.001 on chi-squared test for trend). A cut-off of 6 cm of the AP hiatal diameter on Valsalva yielded a specificity of 0.64 and a sensitivity of 0.7 for detecting significant prolapse on ultrasound.

CONCLUSION

Hiatal ballooning can be diagnosed with 2D translabial ultrasound. We propose that an AP hiatal diameter on Valsalva of up to 5.99 cm be regarded as normal, with 6-<6.5 cm defined as mild, 6.5-<7 cm as 'moderate', 7-<7.5 cm as 'marked' and 7.5 or more as 'severe' ballooning.

Normal vulvovaginal, perineal, and pelvic anatomy with reconstructive considerations

A thorough insight into the female genital anatomy is crucial for understanding and performing pelvic reconstructive procedures. The intimate relationship between the genitalia and the muscles, ligaments, and fascia that provide support is complex, but critical to restore during surgery for correction of prolapse or aesthetic reasons. The external female genitalia include the mons pubis, labia majora and minora, clitoris, vestibule with glands, perineal body, and the muscles and fascia surrounding these structures. Through the perineal membrane and the perineal body, these superficial vulvar structures are structurally related to the deep pelvic muscle levator ani with its fascia. The levator ani forms the pelvic floor with the coccygeus muscle and provides vital support to all the pelvic organs and stability to the perineum. The internal female genital organs include the vagina, cervix, uterus, tubes, and ovaries with their visceral fascia. The visceral fascia also called the endopelvic fascia, surrounds the pelvic organs and connects them to the pelvic walls. It is continuous with the paraurethral and paravaginal fascia, which is attached to the perineal membrane. Thus, the internal and external genitalia are closely related to the muscles and fascia, and work as one functioning unit.

Pubic bone injuries in primiparous women: magnetic resonance imaging in detection and differential diagnosis of structural injury

OBJECTIVE

To evaluate the utility of magnetic resonance imaging (MRI) in diagnosing structural injury in primiparous women at risk for pelvic floor injury.

METHODS

This was an observational study of 77 women who underwent 3T MRI after delivery. Women were operationally defined as high risk (n = 45) for levator ani muscle tears (risk factors: second-stage labor > 150 min or < 30 min, anal sphincter tear, forceps, maternal age > 35 years and birth weight > 4000 g) or low risk (n = 32): vaginally delivered without these risk factors (n = 12); delivered by Cesarean section after second-stage labor > 150 min (n = 14) or delivered by Cesarean section without labor (n = 6). All women were imaged using fluid-sensitive MRI sequences. Two musculoskeletal radiologists reviewed images for bone marrow edema, fracture, pubic symphysis measurements and levator ani tear.

RESULTS

MRI showed pubic bone fractures in 38% of women at high risk for pelvic floor injury and in 13% of women at low risk for pelvic floor injury (χ(2) (3) = 9.27, P = 0.03). Levator ani muscle tears were present in 44% of the high-risk women and in 9% of the low-risk women (χ(2) (3) = 11.57, P = 0.010). Bone marrow edema in the pubic bones was present in 61% of women studied across delivery categories. Complex patterns of injury included combinations of bone marrow edema, fractures, levator ani tears and pubic symphysis injuries. No MRI-documented injuries were present in 18% of women at high risk and 44% at low risk for pelvic floor injury (χ(2) (1) = 6.2, P = 0.013).

CONCLUSIONS

Criteria identifying primiparous women at risk for pelvic floor injury can predict increased risk of bone and soft tissue changes at the pubic symphysis. Fluid-sensitive MRI has utility for differential diagnosis of structural injury in postpartum women.

Dynamics of female pelvic floor function using urodynamics, ultrasound and Magnetic Resonance Imaging (MRI)

In this review the diagnostic potential of evaluating female pelvic floor muscle (PFM) function using magnetic and ultrasound imaging in the context of urodynamic observations is considered in terms of determining the mechanisms of urinary continence. A new approach is used to consider the dynamics of PFM activity by introducing new parameters derived from imaging. Novel image-processing techniques are applied to illustrate the static anatomy and dynamics of PFM function of stress incontinent women pre- and post-operatively as compared to asymptomatic subjects. Function was evaluated from the dynamics of organ displacement produced during voluntary and reflex activation. Technical innovations include the use of ultrasound analysis for movement of structures during maneuvers that are associated with external stimuli. Enabling this approach is the development of criteria and fresh and unique parameters that define the kinematics of PFM function. Principal among these parameters, are displacement, velocity, acceleration and the trajectory of pelvic floor landmarks. To accomplish this objective, movement detection, including motion tracking algorithms and segmentation algorithms were developed to derive new parameters of trajectory, displacement, velocity and acceleration, and strain of pelvic structures during different maneuvers. Results highlight the importance of timing the movement and deformation to fast and stressful maneuvers, which are important for understanding the neuromuscular control and function of PFM. Furthermore, observations suggest that timing of responses is a significant factor separating the continent from the incontinent subjects.

Subject specific finite elasticity simulations of the pelvic floor

An anatomically realistic computational model of the pelvic floor and anal canal regions was used in this study to examine the mechanics of normal defecatory function within the female pelvic floor. This subject specific, MRI-based model enabled mechanical simulations to be performed and quantitatively assessed against experimental data retrieved from the same volunteer. The levator ani muscle group mesh was used as the domain over which the governing equations of finite elasticity were solved using the finite element method with a Mooney-Rivlin material law. Deformation of the levator ani was simulated during a 'bear down' maneuver in order to visualize the way this muscle group functions in an asymptomatic subject. A pressure of 4 kPa was imposed on the mesh and the computed mesh displacements were compared to those obtained from dynamic MR images with an average, experimentally consistent, downwards displacement of 27.2 mm being achieved. The RMS error for this movement was 0.7 mm equating to a percentage error of 2.6% in the supero-inferior direction and 13.7 mm or 74.5% in the antero-posterior direction.

Pelvic floor anatomy and applied physiology

Pelvic floor muscles have two major functions: they provide support or act as a floor for the abdominal viscera including the rectum; and they provide a constrictor or continence mechanism to the urethral, anal, and vaginal orifices (in females). This article discusses the relevance of pelvic floor to the anal opening and closure function, and discusses new findings with regards to the role of these muscles in the vaginal and urethra closure mechanisms.

The spinal nucleus of the bulbocavernosus: firsts in androgen-dependent neural sex differences

Cell number in the spinal nucleus of the bulbocavernosus (SNB) of rats was the first neural sex difference shown to differentiate under the control of androgens, acting via classical intracellular androgen receptors. SNB motoneurons reside in the lumbar spinal cord and innervate striated muscles involved in copulation, including the bulbocavernosus (BC) and levator ani (LA). SNB cells are much larger and more numerous in males than in females, and the BC/LA target muscles are reduced or absent in females. The relative simplicity of this neuromuscular system has allowed for considerable progress in pinpointing sites of hormone action, and identifying the cellular bases for androgenic effects. It is now clear that androgens act at virtually every level of the SNB system, in development and throughout adult life. In this review we focus on effects of androgens on developmental cell death of SNB motoneurons and BC/LA muscles; the establishment and maintenance of SNB motoneuron soma size and dendritic length; BC/LA muscle morphology and physiology; and behaviors controlled by the SNB system. We also describe new data on neurotherapeutic effects of androgens on SNB motoneurons after injury in adulthood.

The OECD program to validate the rat Hershberger bioassay to screen compounds for in vivo androgen and antiandrogen responses: phase 2 dose-response studies

OBJECTIVE

The Organisation for Economic Co-operation and Development (OECD) has completed phase 2 of an international program to validate the rodent Hershberger bioassay.

DESIGN

The Hershberger bioassay is designed to identify suspected androgens and antiandrogens based on changes in the weights of five androgen-responsive tissues (ventral prostate, paired seminal vesicles and coagulating glands, the levator ani and bulbocavernosus muscles, the glans penis, and paired Cowper's or bulbourethral glands). Protocol sensitivity and reproducibility were tested using two androgen agonists (17alpha-methyl testosterone and 17beta-trenbolone), four antagonists [procymi-done, vinclozolin, linuron, and 1,1-dichoro-2,2-bis-(p-chlorophenyl)ethylene (p,p'-DDE)], and a 5alpha-reductase inhibitor (finasteride). Sixteen laboratories from seven countries participated in phase 2.

RESULTS

In 40 of 41 studies, the laboratories successfully detected substance-related weight changes in one or more tissues. The one exception was with the weakest antiandrogen, linuron, in a laboratory with reduced sensitivity because of high coefficients of variation in all tissue weights. The protocols performed well under different experimental conditions (e.g., strain, diet, housing protocol, bedding, vehicle). There was good agreement and reproducibility among laboratories with regard to the lowest dose inducing significant effects on tissue weights.

CONCLUSIONS

The results show that the OECD Hershberger bioassay protocol is reproducible and transferable across laboratories with androgen agonists, weak androgen antagonists, and a 5alpha-reductase inhibitor. The next validation phase will employ coded test substances, including positive substances and negative substances having no androgenic or antiandrogenic activity.

The OECD program to validate the rat Hershberger bioassay to screen compounds for in vivo androgen and antiandrogen responses. Phase 1: use of a potent agonist and a potent antagonist to test the standardized protocol

The Organisation for Economic Cooperation and Development (OECD) has completed phase 1 of the Hershberger validation intended to identify in vivo activity of suspected androgens and antiandrogens. Seventeen laboratories from 7 countries participated in phase 1, and results were collated and evaluated by the OECD with the support of an international committee of experts. Five androgen-responsive tissues (ventral prostate, paired seminal vesicles and coagulating glands, levator ani and bulbocavernosus muscles, glans penis, and paired Cowper's or bulbourethral glands) were evaluated. The standardized protocols used selected doses of a reference androgen, testosterone propionate (TP), and an antiandrogen, flutamide (FLU). All laboratories successfully detected TP-stimulated increases in androgen-responsive tissue weight and decreases in TP-stimulated tissue weights when FLU was co-administered. The standardized protocols performed well under a variety of conditions (e.g., strain, diet, housing protocol, bedding). There was good agreement among laboratories with regard to the TP doses inducing significant increases in tissue weights and the FLU doses decreasing TP-stimulated tissue weights. Several additional procedures (e.g., weighing of the dorsolateral prostate and fixation of tissues before weighing) and serum component measurements (e.g., luteinizing hormone) were also included by some laboratories to assess their potential utility. The results indicated that the OECD Hershberger protocol was robust, reproducible, and transferable across laboratories. Based on this phase 1 validation study, the protocols have been refined, and the next phase of the OECD validation program will test the protocol with selected doses of weak androgen agonists, androgen antagonists, a 5alpha-reductase inhibitor, and chemicals having no androgenic activity.

The pathophysiology of pelvic floor disorders: evidence from a histomorphologic study of the perineum and a mouse model of rectal prolapse

The muscle changes related to pelvic floor disorders are poorly understood. We conducted an anatomical and histological study of the perineum of the normal mouse and of a transgenic mouse strain deficient in urokinase-type plasminogen activator (uPA-/-) that was previously reported to develop a high incidence of rectal prolapse. We could clearly identify the iliococcygeus (ILC) and pubococcygeus (PC) muscles and anal (SPA) and urethral (SPU) sphincters in male and female mice. The bulbocavernosus (BC), ischiocavernosus (ISC) and levator ani (LA) muscles could be found only in male mice. Histochemical analysis of the pelvic floor muscles revealed a majority of type IIA fibres. Rectal prolapses were observed only in male uPA-/- mice. The most obvious finding was an irreducible evagination of the rectal mucosa and a swelling of the entire perineal region corresponding to an irreducible hernia of the seminal vesicles through the pelvic outlet. The hernia caused stretching and thinning of the ISC, BC and LA. Myopathic damage, with degenerated and centronucleated myofibres, were observed in these muscles. The PC, ILC, SPA and SPU were not affected. This study provides an original description of a model of pelvic floor disorder and illustrates the differences existing between the perineum of humans and that of a quadruped species. In spite of these differences, the histopathologic changes observed in the pelvic floor muscles of uPA-/- mice with rectal prolapse suggest that prolonged muscular stretching causes a primary myopathic injury. This should be taken into account in the evaluation of pelvic floor disorders.

Direct androgenic regulation of calcitonin gene-related peptide expression in motoneurons of rats with mosaic androgen insensitivity

The spinal nucleus of the bulbocavernosus (SNB) and its target muscles, bulbocavernosus and levator ani (BC/LA), form a sexually dimorphic neuromuscular circuit whose development and maintenance are androgen-dependent. The mechanisms whereby androgen regulates gene expression in the SNB of adult rats are largely unknown, although a retrograde influence from the BC/LA muscles has been suggested to underlie the suppression of calcitonin gene-related peptide (CGRP) expression observed in SNB motoneurons after systemic androgen treatment. A mosaic paradigm was used to determine the site of action of androgen in the regulation of CGRP expression in SNB motoneurons. As a consequence of random X chromosome inactivation, androgenized female rats heterozygous for the tfm androgen receptor (AR) mutation (XwtXtfm-mosaics) express a mosaic of androgen-sensitive and androgen-insensitive motoneurons in the SNB, whereas the BC/LA target musculature appears to be uniformly sensitive to androgens. In adult mosaics, testosterone administration resulted in a reduction in the proportion of androgen-sensitive cells expressing CGRP, whereas no such reduction was observed in the androgen-insensitive population, indicating that neuronal AR plays an essential role in the neuromuscular regulation of CGRP expression in these motoneurons. This provides the first in vivo demonstration of AR regulation of gene expression unambiguously localized to a neuronal population.