Anatomical and functional significance of urogenital hiatus in primary urodynamic stress incontinence

3D Ultrasound in Pelvic Floor: Is It Useful as a Prognostic Tool in Type of Labor Development and Subsequent Pelvic Floor Diseases?

The objective of our study is to determine the thickness of the pubovisceral fasciculus of the levator ani muscle and the area of the genital hiatus by means of three-dimensional perineal ultrasound, in pregnant women in the 2nd trimester, and to analyze the related maternal, perinatal and postpartum clinical variables. Furthermore, to compare the results of our study with two similar series previously published. An observational, prospective study of pelvic floor ultrasound was carried out, performed at week 20, whose delivery was attended in the obstetrics service of the Hospital General Universitario Gregorio Marañón de Madrid (HGUGM), during the period of August from 2021 to June 2022. Maternal, ultrasound, perinatal and postpartum clinical variables were collected from each participant. During the study period, a total of 54 patients were included in it. The mean gestational age at which the ultrasound was performed was 19.81 ± 0.91 weeks. In relation to the ultrasound variables, the mean thickness of the pubovisceral muscle was 0.87 ± 0.13 cm (95% CI, 0.64-1.38 cm), while, in the plane of minimum dimension of the genital hiatus, the hiatal area at rest was 13.41 ± 3.22 (95% CI, 4.60-18.78) cm². There is a significant correlation between the age of pregnant women (over 35 years of age) and the increase in the area of the genital hiatus (r = 0.295, p = 0.031). 3D ultrasound of the pelvic floor performed at week 20 of gestation can to be an effective, non-invasive, reproducible and cheap tool in the prognosis of the development of labor and of possible subsequent perineal dysfunctions.

UROKIN: A Software to Enhance Our Understanding of Urogenital Motion

Transperineal ultrasound (TPUS) allows for objective quantification of mid-sagittal urogenital mechanics, yet current practice omits dynamic motion information in favor of analyzing only a rest and a peak motion frame. This work details the development of UROKIN, a semi-automated software which calculates kinematic curves of urogenital landmark motion. A proof of concept analysis, performed using UROKIN on TPUS video recorded from 20 women with and 10 women without stress urinary incontinence (SUI) performing maximum voluntary contraction of the pelvic floor muscles. The anorectal angle and bladder neck were tracked while the motion of the pubic symphysis was used to compensate for the error incurred by TPUS probe motion during imaging. Kinematic curves of landmark motion were generated for each video and curves were smoothed, time normalized, and averaged within groups. Kinematic data yielded by the UROKIN software showed statistically significant differences between women with and without SUI in terms of magnitude and timing characteristics of the kinematic curves depicting landmark motion. Results provide insight into the ways in which UROKIN may be useful to study differences in pelvic floor muscle contraction mechanics between women with and without SUI and other pelvic floor disorders. The UROKIN software improves on methods described in the literature and provides unique capacity to further our understanding of urogenital biomechanics.

On the Stiffness of the Mesh and Urethral Mobility: A Finite Element Analysis

Midurethral slings are used to correct urethral hypermobility in female stress urinary incontinence (SUI), defined as the complaint of involuntary urine leakage when the intra-abdominal pressure (IAP) is increased. Structural and thermal features influence their mechanical properties, which may explain postoperative complications, e.g., erosion and urethral obstruction. We studied the effect of the mesh stiffness on urethral mobility at Valsalva maneuver, under impairment of the supporting structures (levator ani and/or ligaments), by using a numerical model. For that purpose, we modeled a sling with “lower” versus “higher” stiffness and evaluated the mobility of the bladder and urethra, that of the urethrovesical junction (the α-angle), and the force exerted at the fixation of the sling. The effect of impaired levator ani or pubourethral ligaments (PUL) alone on the organs displacement and α-angle opening was similar, showing their important role together on urethral stabilization. When the levator ani and all the ligaments were simulated as impaired, the descent of the bladder and urethra went up to 25.02 mm, that of the bladder neck was 14.57 mm, and the α-angle was 129.7 deg, in the range of what was found in women with SUI. Both meshes allowed returning to normal positioning, although at the cost of higher force exerted by the mesh with higher stiffness (3.4 N against 2.3 N), which can relate to tissue erosion. This finite element analysis allowed mimicking the biomechanical response of the pelvic structures in response to changing a material property of the midurethral synthetic mesh.

Clinical Importance and Surgical Outcomes of Green Type III Cystocele in Women With Anterior Vaginal Prolapse

OBJECTIVES

To explore the clinical importance and surgical outcomes of Green type III cystocele in women with anterior vaginal prolapse.

METHODS

A database of 336 women with a Ba point higher than -3 cm on the Pelvic Organ Prolapse Quantification system was retrospectively reviewed. Investigated data comprised those obtained from a clinical interview, the Pelvic Organ Prolapse Quantification system, and sonography. Initially, the baseline data between women with (n = 126) and without (n = 210) Green type III cystocele on sonography were compared. Subsequently, 6-month postoperative data between women who had Green type III cystocele on sonography and underwent either anterior colporrhaphy (n = 25) or a Perigee procedure (n = 76) were compared.

RESULTS

Women with Green type III cystocele had symptoms of voiding dysfunction more frequently, stress urinary incontinence less frequently, and more bulging (mean ± SD, 2.7 ± 1.2 versus 1.9 ± 1.5 for women with versus without Green type III cystocele; P = .001), a greater likelihood of stage II or higher cystocele (86.5% versus 60.0% for women with versus without Green type III cystocele; P < .001), as well as more caudodorsal bladder neck and genitohiatal positions and a wider genital hiatus on sonography. Women with Green type III cystocele had a greater likelihood of stage 0 cystocele (64.0% versus 89.5% for anterior colporrhaphy versus Perigee; P< .001) and more ventral bladder neck positions after Perigee procedures.

CONCLUSIONS

The presence of Green type III cystocele in women with anterior vaginal prolapse is associated with more functional impairments and anatomic defects. Despite comparable functional outcomes, Perigee procedures provide better anatomic outcomes for the anterior vagina in women with Green type III cystocele than anterior colporrhaphy does in the short term.

Ultrasound Characteristics of Patients with Urinary Stress Incontinence with or without Genital Prolapse

Purpose

The study purpose was to evaluate the clinical and ultrasound characteristics of women with urinary stress incontinence (USI) with or without genital prolapse (GP).

Materials and Methods

A total of 268 patients who underwent ultrasound perineal evaluation were divided into two groups: isolated USI (n=132) and USIGP (n=136) with USI/GP stage I/II. The latter group was additionally divided into two subgroups: USIGP(A) (n=78) with USI/GP stage I and USIGP(B) (n=58) with USI/GP stage II.

Results

Point Aa (pelvic organ prolapse quantification system), which is the projection of the bladder neck (BN) on the anterior vaginal wall, was situated higher in the rest position (RP) but moved lower during a Valsalva maneuver (VM) in the USI group than in the USIGP group (p<0.05). The ultrasound parameters α-angle and the distance Sy-BN (symphisis-bladder neck) decreased, whereas distance H increased, in the USIGP group during VM. The ultrasound parameters that gave the best insight into the range of BN movements were as follows: distance R→V and angle of rotation (ρ), which were significantly higher in the USI group than in the USIGP group during VM.

Conclusions

According to the clinical and ultrasound findings, we can conclude that the BN is situated higher during the RP but moved lower during a VM in patients with isolated USI compared with those with concomitant USI/GP, which could be explained by the cystocele-immobilizing effect on the BN during the VM in the latter group but also by the deteriorated pubo-urethral ligaments in the former group.

Clinical and pathophysiological correlates of the symptom severity of stress urinary incontinence

INTRODUCTION AND HYPOTHESIS

The pathophysiology of stress urinary incontinence (SUI) is multifactorial. The aim of this study was to explore the factor determining the symptom severity of SUI.

METHODS

One hundred twenty-four women with SUI were retrospectively investigated. Clinical data for analyses included demographics, pelvic organ prolapse quantification, SUI severity using a 4-point Likert scale, ultrasound, 1-h pad tests, and urodynamic studies. Data were analyzed using the Spearman's rho test and Kruskal-Wallis test.

RESULTS

The symptom severity was not correlated with risk factors of SUI or the morphologic manifestations representing urethral support defect, but was significantly correlated with urine loss on 1-h pad test, Valsalva leak point pressure (VLPP) grading, and maximum urethral closure pressure (MUCP). Women with higher SUI severity had greater urine loss on 1-h pad tests, worse VLPP grading, and lower MUCP.

CONCLUSIONS

Urethral sphincter function appears to be an important determinant for the symptom severity of SUI.

Validation of new ultrasound parameters for quantifying pelvic floor muscle contraction

OBJECTIVE

To determine the reliability and validity of new ultrasound parameters, measured in the polar coordinate system, for quantifying pelvic floor muscle action.

METHODS

This was a prospective study, from January 2005 to December 2007, in 209 women with urodynamic stress incontinence, to validate new ultrasound parameters for quantifying pelvic floor muscle contraction. The examination of each patient included intravaginal digital palpation of voluntary pelvic floor muscle contractility and an ultrasound assessment of the positions of the bladder neck and anorectal junction at rest and during pelvic floor muscle contraction. The position of the bladder neck was expressed by bladder neck angle and bladder neck distance from the lower border of the pubic symphysis, and the position of the anorectal junction was expressed by the levator hiatal angle and sagittal hiatal diameter. The vector lengths of the motion of the bladder neck and anorectal junction during pelvic floor muscle contraction were calculated from the positions at rest and during pelvic floor muscle contraction by mathematical formulae.

RESULTS

There was good inter- and intraobserver reliability of measurement of ultrasound parameters on stored volumes. During pelvic floor muscle contraction, elevated bladder neck distance and shortened sagittal hiatal diameter were valid parameters representing stronger pelvic floor muscle contractility, with shortened sagittal hiatal diameter having the best correlation (r = - 0.348, P < 0.001).

CONCLUSION

The methods used in this study appear to be reliable for quantifying pelvic floor muscle action. The bladder neck distance with respect to the lower border of the pubic symphysis and the sagittal hiatal diameter were both valid parameters reflecting PFM contractility.

Three-dimensional transperineal ultrasonography of the pelvic floor: improving visualization for new clinical applications and better functional assessment

OBJECTIVE

With increasing awareness of the scope of pelvic floor disorders has come development and introduction into clinical practice of new imaging techniques, with increasing importance of ultrasonography. Complex pelvic floor anatomy, the conceptual difficulty in the basics of some pelvic floor disorders, and the uneven standardization of ultrasonographic techniques were the impetuses of this review. The purpose of this study was to review the basic anatomy of the pelvic floor and the transperineal ultrasonographic evaluation technique and to provide an overview of the current clinical use of 3-dimensional transperineal ultrasonography in the evaluation of the anterior and posterior pelvic floor compartments.

METHODS

A literature review illustrated with index cases from our center was conducted.

RESULTS

Ultrasonography has been widely applied to evaluation of the anterior and posterior compartments of the pelvic floor. Three-dimensional ultrasonography has a role in improving pelvic floor assessment.

CONCLUSIONS

Three-dimensional transperineal ultrasonography has been applied to evaluation of normal and pathologic pelvic floor anatomy. Practical application, through well-designed and sufficiently powered clinical studies, will establish the association between the clinical presentations of dysfunction with ultrasonographic findings.

Three-dimensional transperineal sonographic characteristics of the anal sphincter complex in nulliparous women

OBJECTIVE

To explore the morphological characteristics and normal biometry of the anal sphincter complex in nulliparous Chinese women using three-dimensional (3D) transperineal ultrasound.

METHODS

3D sonographic data from 55 nulliparous Chinese women (aged 19-38 years) who had no pelvic organ prolapse and no symptoms of pelvic floor dysfunction were retrieved from an image dataset and analyzed by offline post-processing. The morphological characteristics of the external and internal anal sphincters, puborectalis muscle and perineal body were assessed in the sagittal, coronal and axial views.

RESULTS

The external anal sphincter had three sonographic components: the circular main body, a subcutaneous part and an extension portion. It was significantly thinner at 12 o'clock than at the 3, 6 and 9 o'clock positions. The internal anal sphincter was seen as dark echolucent strips of equal thickness. In the mid-sagittal view, it started from the anal verge and ended at the anorectal junction. The perineal body was an ovoid structure covering the upper margin of the external sphincter, while the puborectalis muscle was banana-shaped in the sagittal view and was located behind the anorectal junction, extending downward along the inferior margin of the posterior external sphincter extension. Sonographic characteristics of the anal sphincter complex did not vary with age, weight, height or body mass index.

CONCLUSIONS

3D transperineal ultrasound clearly demonstrates the spatial relationships of each component of the anal sphincter complex. This should allow standardized measurement of the complex for investigations of its function.

Ultrasound evaluation of dynamic responses of female pelvic floor muscles

Ultrasound imaging of the pelvic floor carries diagnostically important information about the dynamic response of the pelvic floor muscles (PFM) to potentially incontinence-producing stress, which cannot be readily captured and assimilated by the observer during the scanning process. We presented an approach based on motion tracking quantitatively to analyze the dynamic parameters of PFM on the ano-rectal angle (ARA). Perineal ultrasonography was performed on 22 asymptomatic females and nine stress urinary incontinent (SUI) patients with a broad age distribution and parity. The ventral-dorsal and cephalad-caudad movements of the ARA were resolved and kinematic parameters, in terms of displacement, trajectory, velocity and acceleration, were analyzed. The results revealed the possible mechanisms of PFM responses to prevent the urine from incontinence in fast and stress events such as coughs. The statistical analyses showed that the PFM responses of the healthy subjects and the SUI patients are significantly different in both the supine and standing experiments.

Biometry of the pubovisceral muscle and levator hiatus in nulliparous Chinese women

OBJECTIVES

To identify using three-dimensional (3D) ultrasound the morphological features and normal biometry of the levator hiatus in nulliparous Chinese women and to explore ethnic differences between these measurements and those in nulliparous Caucasian women.

METHODS

3D sonographic data from 59 nulliparous Chinese women (aged 19-38 years) who had no pelvic organ prolapse and no symptoms of pelvic floor dysfunction were retrieved from an image dataset and analyzed by offline post-processing. The pubovisceral muscle and levator hiatus were measured in the planes of maximal pubovisceral muscle thickness and minimum hiatal dimension, respectively. In addition, the genitohiatal and levator ani angles were measured. These values were compared with those in a published study of Caucasian women.

RESULTS

In Chinese women there was no relationship between minimum anteroposterior (AP) hiatal diameter and minimum lateral hiatal diameter. Body weight was correlated with hiatal area and minimum AP hiatal diameter (r = 0.391, P = 0.003 and r = 0.378, P = 0.004, respectively), whereas body mass index was correlated only with minimum AP hiatal diameter (r = 0.349, P = 0.008). There was a significant difference in average pubovisceral muscle thickness (P = 0.001) between nulliparous Chinese and Caucasian women.

CONCLUSIONS

Body weight, body mass index, and ethnicity are factors affecting the biometry of the levator hiatus in Chinese nulliparous women.