Compliance of the bladder neck supporting structures: importance of activity pattern of levator ani muscle and content of elastic fibers of endopelvic fascia

Association Between Urinary Stress Incontinence and Levator Avulsion Detected by 3D Transperineal Ultrasound

PURPOSE

 To determine the association between levator avulsion and urinary stress incontinence (USI) by 3/4D transperineal ultrasound.

MATERIALS AND METHODS

 842 patients who were admitted to our hospital from 2016 to 2019 were recruited for our study. 3D/4D transperineal ultrasound was performed. After standard interview and clinical evaluation, general conditions and levator hiatus data were collected and measured to compare with each group. The odds ratio (OR) of USI symptoms or ultrasound features with levator avulsion were calculated.

RESULTS

 A total of 593 women were studied: 204 suffered from levator avulsion (96 cases of left-side avulsion, 80 cases of right-side avulsion and 28 cases of bilateral avulsion) and 389 women had no avulsion. The gravidity and episiotomy conditions of the avulsion groups were significantly different from the no-avulsion group. Significant differences were found in the transverse diameters and anteroposterior diameters between the levator avulsion group and the no-avulsion group, but there was no difference among the avulsion groups, regardless of whether the patient was at rest or performing the Valsalva maneuver. Interestingly, a significant difference was found in the presence of USI symptoms between the uni-avulsion group and the no-avulsion group. The odds ratio (OR) of USI symptoms in the uni-avulsion group is 2.786 (95 %CI, 1.663-4.669), but 0.939 (95 %CI, 0.276-3.199) for the bilateral avulsion and no-avulsion groups.

CONCLUSION

 Unilateral levator avulsion may be a risk factor for urinary stress incontinence.

The pathophysiology of stress urinary incontinence: a systematic review and meta-analysis

Introduction and hypothesis

To evaluate the evidence for pathologies underlying stress urinary incontinence (SUI) in women.

Methods

For the data sources, a structured search of the peer-reviewed literature (English language; 1960–April 2020) was conducted using predefined key terms in PubMed and Embase. Google Scholar was also searched. Peer-reviewed manuscripts that reported on anatomical, physiological or functional differences between females with signs and/or symptoms consistent with SUI and a concurrently recruited control group of continent females without any substantive urogynecological symptoms. Of 4629 publications screened, 84 met the inclusion criteria and were retained, among which 24 were included in meta-analyses.

Results

Selection bias was moderate to high; < 25% of studies controlled for major confounding variables for SUI (e.g., age, BMI and parity). There was a lack of standardization of methods among studies, and several measurement issues were identified. Results were synthesized qualitatively, and, where possible, random-effects meta-analyses were conducted. Deficits in urethral and bladder neck structure and support, neuromuscular and mechanical function of the striated urethral sphincter (SUS) and levator ani muscles all appear to be associated with SUI. Meta-analyses showed that observed bladder neck dilation and lower functional urethral length, bladder neck support and maximum urethral closure pressures are strong characteristic signs of SUI.

Conclusion

The pathology of SUI is multifactorial, with strong evidence pointing to bladder neck and urethral incompetence. While there is also evidence of impaired urethral support and levator ani function, standardized approaches to measurement are needed to generate higher levels of evidence.

Proprioception in stress urinary incontinence: A narrative review

Background: Urinary incontinence (UI) is more common than any other chronic disease. Stress urinary incontinence (SUI), among the various forms of urinary incontinence, is the most prevalent (50%) type of this condition. Female urinary continence is maintained through an integrated function of pelvic floor muscles (PFMs), fascial structures, nerves, supporting ligaments, and the vagina. In women with SUI, the postural activity of the PFMs is delayed and the balance ability is decreased. Many women, by learning the correct timing of a pelvic floor contraction during a cough, are able to eliminate consequent SUI. Timing is an important function of motor coordination and could be affected by proprioception. This study was conducted to review and outline the literature on proprioception as a contributory factor in SUI.

Methods: PubMed, Scopus, and Google Scholar databases were systematically searched from 1998 to 2017 for articles on the topic of pathophysiology, motor control alterations, and proprioception role in women with SUI.

Results: A total of 6 articles addressed the importance of proprioception in motor control and its alterations in women with SUI. There were also publications on postural control, balance, and timing alterations in women with SUI in the literature. However, there was no research on measuring proprioception in the pelvic floor in this group.

Conclusion: Both the strength of the PFMs and the contraction timing and proprioception are important factors in maintaining continence. Thus, conducting research on PFMs proprioception in women with SUI, as a cause of incontinence, is encouraged.

Pelvic floor muscle activity during fast voluntary contractions in continent and incontinent women

AIMS

Stress urinary incontinence (SUI) has also been attributed to a lower speed of contraction of the pelvic floor muscles (PFM). Therefore, PFM assessment and training implement fast voluntary contractions (FVC). The purpose of the study was to explore FVC regarding feasibility, on-/offset and rate of activity determination, as well as differences between continent (CON) and stress urinary incontinent (SUI) women.

METHODS

Fifty women were included and examined by means of PFM EMG during rest, maximum voluntary contractions (MVC), and five FVC. MVC-peak activity was used to normalize EMG-data. On-/offset of muscle activity was determined as mean of rectified rest activity plus 1 standard deviation. Linear regression was calculated for rate of activity from onset to peak, peak to offset, and within 200 ms after both onset and peak. Peak activity and time variables related to onset, peak, and offset were calculated.

RESULTS

On-/offsets were evaluable for 234/222 of 250 FVC by a computer-based algorithm, 16/28 on-/offsets had to be determined manually. There was no significant difference between groups (CON/SUI) regarding FVC peak (92.1/99.3 %MVC), time to peak (514.2/525.6 ms), and increase of activity (182.8/182.1 %MVC/s). The SUI group showed a significantly slower activity decrease (-120.7/-74.4 %MVC/s).

CONCLUSIONS

FVC analyses were shown to be feasible. The significant difference observed between the groups did not refer to activity increase but instead to a prolonged relaxation phase in the SUI group. This prompts to reconsider the interpretation of FVC in PFM testing and training.

Evaluation of pelvic floor kinematics in continent and incontinent women during running: An exploratory study

AIMS

Impact activity like running is associated with an increase in intra-abdominal pressure which needs to be sufficiently countered by pelvic floor muscle (PFM) activity to secure continence. The aim of this study was to investigate and compare PFM kinematics in continent and incontinent women during running.

METHOS

Three-dimensional position and orientation was measured with the electromagnetic tracking device trakSTAR™. One sensor was attached to the vaginal probe and a second one was secured to the subjects' skin at the height of the second sacral vertebrae. Cranial-caudal and forward-backward displacement of the vaginal probe was measured during 10 sec running on a treadmill at the speeds 7, 11, and 15 km/h. Displacement data from 100 ms before to 300 ms after heel-strike were analyzed.

RESULTS

Nineteen incontinent and twenty-seven continent women were included in this study. Before the foot touched the ground caudal translation and forward rotation of the vaginal probe was detected, whereas after heel-strike a cranial translation and backward rotation was measured. Cranial-caudal translation as well as backward-forward-rotation did not differ significantly between continent and incontinent subjects for the three speeds. Analysis of maximum displacements showed significantly increasing displacement with increasing speeds.

CONCLUSIONS

Kinematic measurements during impact activity of running demonstrated caudal translation before and cranial translation after heel-strike. The hypothesis of caudal translation through impact activity was not confirmed. Patterns seem similar between continent and incontinent subjects. Associations between the direction of displacement and muscle action of PFMs remain assumptions.

Cystocele and functional anatomy of the pelvic floor: review and update of the various theories

INTRODUCTION AND HYPOTHESIS

We updated anatomic theories of pelvic organ support to determine pathophysiology in various forms of cystocele.

METHODS

PubMed/MEDLINE, ScienceDirect, Cochrane Library, and Web of Science databases were searched using the terms pelvic floor, cystocele, anatomy, connective tissue, endopelvic fascia, and pelvic mobility. We retrieved 612 articles, of which 61 matched our topic and thus were selected. Anatomic structures of bladder support and their roles in cystocele onset were determined on the international anatomic classification; the various anatomic theories of pelvic organ support were reviewed and a synthesis was made of theories of cystocele pathophysiology.

RESULTS

Anterior vaginal support structures comprise pubocervical fascia, tendinous arcs, endopelvic fascia, and levator ani muscle. DeLancey's theory was based on anatomic models and, later, magnetic resonance imaging (MRI), establishing a three-level anatomopathologic definition of prolapse. Petros's integral theory demonstrated interdependence between pelvic organ support systems, linking ligament-fascia lesions, and clinical expression. Apical cystocele is induced by failure of the pubocervical fascia and insertion of its cervical ring; lower cystocele is induced by pubocervical fascia (medial cystocele) or endopelvic fascia failure at its arcus tendineus fasciae pelvis attachment (lateral cystocele).

CONCLUSIONS

Improved anatomic knowledge of vaginal wall support mechanisms will improve understanding of cystocele pathophysiology, diagnosis of the various types, and surgical techniques. The two most relevant theories, DeLancey's and Petros's, are complementary, enriching knowledge of pelvic functional anatomy, but differ in mechanism. Three-dimensional digital models could integrate and assess the mechanical properties of each anatomic structure.

Pelvic floor muscle displacement during voluntary and involuntary activation in continent and incontinent women: a systematic review

INTRODUCTION

Investigations of the dynamic function of female pelvic floor muscles (PFM) help us to understand the pathophysiology of stress urinary incontinence (SUI). Displacement measurements of PFM give insight into muscle activation and thus help to improve rehabilitation strategies. This systematic review (PROSPERO 2013: CRD42013006409) was performed to summarise the current evidence for PFM displacement during voluntary and involuntary activation in continent and incontinent women.

METHODS

MEDLINE, EMBASE, Cochrane and SPORTDiscus databases were searched using selected terminology reflecting the PICO approach. Screening of Google Scholar and congress abstracts added to further information. Original articles investigating PFM displacement were included if they reported on at least one of the aims of the review, e.g., method, test position, test activity, direction and quantification of displacement, as well as the comparison between continent and incontinent women. Titles and abstracts were screened by two reviewers. The papers included were reviewed by two individuals to ascertain whether they fulfilled the inclusion criteria and data were extracted on outcome parameters.

RESULTS

Forty-two predominantly observational studies fulfilled the inclusion criteria. A variety of measurement methods and calculations of displacement was presented. The sample was heterogeneous concerning age, parity and continence status. Test positions and test activities varied among the studies.

CONCLUSIONS

The findings summarise the present knowledge of PFM displacement, but still lack deeper comprehension of the SUI pathomechanism of involuntary, reflexive activation during functional activities. We therefore propose that future investigations focus on PFM dynamics during fast and stressful impact tasks.

Factors affecting reflex pelvic floor muscle contraction patterns in women with pelvic floor disorders

OBJECTIVE

To explore factors affecting the presence of two reflex pelvic floor muscle contraction (PFMC) patterns in women with pelvic floor disorders.

METHODS

This was a retrospective analysis of pelvic floor ultrasonography and urodynamic data for 667 consecutive symptomatic women with pelvic floor disorders. We identified on ultrasonography the presence or absence of two reflex PFMC patterns, anorectal lift (ARL) and inward clitoral motion (ICM), preceding or occurring during coughing, and evaluated their associations with possible factors affecting reflex PFMC reactivity, including patient demographics, pelvic organ prolapse stages, ultrasonography findings and urodynamic data.

RESULTS

Of the 667 women, 560 (84.0%) clearly demonstrated reflex ARL and 536 (80.4%) demonstrated ICM. There were significant differences in age (P < 0.001), parity (P = 0.033) and menopausal status (P = 0.005) between women with and those without reflex ICM before or during coughing. The multivariable logistic regression model showed that age was the only independent factor associated with presence of reflex ICM (odds ratio, 0.93 (95% CI, 0.88-0.99), P = 0.017). In contrast, no significant differences were noted between women with and without reflex ARL.

CONCLUSIONS

Increasing age is negatively associated with the presence of reflex ICM during coughing in symptomatic women with pelvic floor disorders.

The role of lumbopelvic posture in pelvic floor muscle activation in continent women

This study was undertaken to determine the effect of changing standing lumbopelvic posture on pelvic floor muscle (PFM) activation amplitude and timing and the resultant vaginal manometry values recorded during static and dynamic tasks. Sixteen nulliparous, continent women between the ages of 22 and 41 years performed five tasks (quiet standing, maximal effort cough, Valsalva manoeuvre, maximum voluntary contraction (MVC) of the PFMs, and a load-catching task) in three different standing postures (normal lumbopelvic posture, hyperlordosis and hypolordosis). Electromyographic (EMG) data were recorded from the PFMs bilaterally using a Periform™ vaginal probe coupled to Delsys™ Bagnoli-8 EMG amplifiers. In separate trials, vaginal manometry was obtained using a Peritron™ perineometer. Lumbopelvic angle was recorded simultaneously with EMG and vaginal manometry using an Optotrak™ 3D motion analysis system to ensure that subjects maintained the required posture throughout the three trials of each task. All data were filtered using a moving 100 ms RMS window and peak values were determined for each trial and task. Repeated-measures analyses of variance were performed on the peak PFM EMG, intra-vaginal pressure amplitudes, and lumbopelvic angles as well as activation onset data for the cough and load-catching tasks. There was significantly higher resting PFM activity in all postures in standing as compared to supine, and in the standing position, there was higher resting PFM activity in the hypo-lordotic posture as compared to the normal and hyperlordotic postures. During the MVC, cough, Valsalva, and load-catching tasks, subjects generated significantly more PFM EMG activity when in their habitual posture than when in hyper- or hypo-lordotic postures. Conversely, higher peak vaginal manometry values were generated in the hypo-lordotic posture for all tasks in all cases. These results clearly indicate that changes in lumbopelvic posture influence both the contractility of the PFMs and the amount of vaginal pressure generated during static postures and during dynamic tasks. Lumbopelvic posture does not, however, appear to have a significant effect on the timing of PFM activation during coughing or load-catching tasks.

Women with stress urinary incontinence demonstrate motor control differences during coughing

INTRODUCTION

This study compared the patterns of pelvic floor muscle (PFM) activity during coughing between women with stress urinary incontinence (SUI) and continent women, using surface electromyography (EMG) and posterior vaginal wall (PVW) pressure.

METHODS

Twenty-four women participated: eight continent, eight with mild SUI and eight with severe SUI. Volunteers performed three maximum coughs in supine and standing. Maximum PFM EMG and PVW pressure amplitudes and the timing of the EMG peak relative to the PVW pressure peak were determined. Ensemble average PVW pressure versus EMG curves were created.

RESULTS

There were no significant differences among the groups in the maximum EMG or PVW pressure amplitudes. The EMG and PVW pressure peaked simultaneously in both positions in the continent group. In the mild SUI group, the EMG and PVW pressure peaked simultaneously in supine, but the EMG peaked before the PVW pressure in standing. In the severe SUI group, the EMG peaked before the PVW pressure in both positions. The shapes of the PVW pressure versus EMG curves were similar among the groups and positions, however the SUI groups displayed higher EMG-intercepts than the continent women.

CONCLUSION

These findings suggest that urine leakage during coughing in women with SUI may be related to delays in force generation rather than PFM weakness.

The effect of levator avulsion on hiatal dimension and function

OBJECTIVE

Pelvic floor trauma as a result of vaginal childbirth can cause significant pelvic floor morbidity. In this observational study, we intended to define whether such trauma is associated with abnormal hiatal biometry and/or abnormal biomechanical properties of the levator muscle.

STUDY DESIGN

The datasets of 414 urogynecologic patients were assessed in a retrospective study. Patients underwent an interview, clinical examination, and 3-/4-dimensional pelvic floor ultrasound. All analysis was performed offline using proprietary software. Hiatal dimensions and strain were measured.

RESULTS

In 21.1% of parous women with a history of vaginal delivery, an avulsion of the levator muscle was diagnosed, and in 8.6% it was bilateral. The relative risk of abnormal distensibility was 3.5 (95% confidence interval, 1.7-6.5) in unilateral and 3.96 (95% confidence interval, 1.7-9.2) in bilateral avulsion. Avulsion increased muscle distensibility on Valsalva and reduced muscle shortening on pelvic floor muscle contraction.

CONCLUSION

Avulsion injury is associated with abnormal levator biometry and function.

Mechanisms of pelvic floor muscle function and the effect on the urethra during a cough

BACKGROUND

Current measurement tools have difficulty identifying the automatic physiologic processes maintaining continence, and many questions still remain about pelvic floor muscle (PFM) function during automatic events.

OBJECTIVE

To perform a feasibility study to characterise the displacement, velocity, and acceleration of the PFM and the urethra during a cough.

DESIGN, SETTING, AND PARTICIPANTS

A volunteer convenience sample of 23 continent women and 9 women with stress urinary incontinence (SUI) from the general community of San Francisco Bay Area was studied.

MEASUREMENTS

Methods included perineal ultrasound imaging, motion tracking of the urogenital structures, and digital vaginal examination. Statistical analysis used one-tailed unpaired student t tests, and Welch's correction was applied when variances were unequal.

RESULTS AND LIMITATIONS

The cough reflex activated the PFM of continent women to compress the urogenital structures towards the pubic symphysis, which was absent in women with SUI. The maximum accelerations that acted on the PFM during a cough were generally more similar than the velocities and displacements. The urethras of women with SUI were exposed to uncontrolled transverse acceleration and were displaced more than twice as far (p=0.0002), with almost twice the velocity (p=0.0015) of the urethras of continent women. Caution regarding the generalisability of this study is warranted due to the small number of women in the SUI group and the significant difference in parity between groups.

CONCLUSIONS

During a cough, normal PFM function produces timely compression of the pelvic floor and additional external support to the urethra, reducing displacement, velocity, and acceleration. In women with SUI, who have weaker urethral attachments, this shortening contraction does not occur; consequently, the urethras of women with SUI move further and faster for a longer duration.

The integrated continence system: a manual therapy approach to the treatment of stress urinary incontinence

Stress urinary incontinence (SUI) constitutes a large-scale public health concern. The integrated continence system (ICS) developed by the authors is an evidence-based model that demonstrates how urinary incontinence is maintained through the interaction of three structural systems (intrinsic urethral closure, urethral support and lumbopelvic stability) and three modifiable factors (motor control, musculoskeletal and behavioural). The purpose of the ICS is first, to demonstrate the important role that manual physiotherapists can play in the treatment of SUI and second, to guide clinical practice decisions in order to improve clinical outcomes among women with SUI.

New imaging method for assessing pelvic floor biomechanics

OBJECTIVES

The investigation of female pelvic floor biomechanics is attracting attention due to its importance in pelvic floor dysfunction and childbirth. To date, there are no established means of assessing pelvic floor elasticity. We propose the use of translabial ultrasound to estimate strain, one element of pubovisceral muscle elasticity.

METHODS

Ultrasound datasets of 98 women seen at a tertiary urogynecology clinic were reviewed using proprietary software. Data were processed to estimate muscle fiber strain during Valsalva and contraction by measuring hiatal circumference and deducting bony arc length. Clinical assessment included levator palpation during maximal contraction (modified Oxford grading scale) and at rest, with tone recorded on a new six-point scale. Analysis of imaging data was performed without knowledge of clinical data.

RESULTS

Mean age was 52.2 (range, 19-87) years and mean parity was 2.4 (range, 0-8). Mean (SD) hiatal area during contraction, rest and Valsalva was 15.4 (3.8) cm(2), 18.9 (5.0) cm(2) and 27.3 (8.9) cm(2), respectively. There was a moderate association between strain during contraction and Oxford grade (r = 0.439, P < 0.0001), and a weak but significant association between strain during Valsalva and resting tone (r = - 0.224, P = 0.033).

CONCLUSIONS

Translabial ultrasound can be used to measure strain, a component of pubovisceral muscle elasticity, and we have validated the technique against clinical assessment. Pubovisceral strain during contraction correlates positively with Oxford grade. Pubovisceral strain during Valsalva correlates negatively with resting tone grade. This new non-invasive ultrasound technique may be of value for assessing patients with pelvic floor dysfunction.

Quantitative analysis of 17 amino acids in the connective tissue of patients with pelvic organ prolapse using capillary electrophoresis-tandem mass spectrometry

The simultaneous determination of 17 amino acids in connective tissue using capillary electrophoresis is described in this study. Separation was carried out on a fused silica capillary column (80 cm x 50 mm i.d.) with 1M formic acid as the running electrolyte. The detection was conducted on a mass spectrometer by selective reaction monitoring (SRM) mode via an electrospray ionization source. Tissue samples were prepared by reduction and acid hydrolysis to extract amino acids; over 84.3% recovery was seen for all compounds. The method allowed for sensitive, reproducible, and reliable quantification, and all 17 amino acids were separated using this method. Good linearity over the investigated concentration ranges was observed, with values of R higher than 0.993 for all the analytes. Precision and accuracy examined at three concentration levels ranged from 0.2% to 19.5% and 84.1% to 120.0%, respectively. Matrix effects were also tested and ranged from -9.1% to 15.4%. The validated method was applied to the quantitation of 17 amino acids in pelvic connective tissue of pelvic organ prolapsed patients. Methionine, glutamine, and histidine were significantly higher in the experimental patients compared to the controls. This suggests that changes in the amino acid concentrations within the connective tissue could be a factor in the genesis of pelvic organ prolapse. Therefore, this method is potentially applicable for amino acid analysis in tissue, providing a more complete understanding of pelvic organ prolapse.

Rehabilitative ultrasound imaging: understanding the technology and its applications

The use of ultrasound imaging by physical therapists is growing in popularity. This commentary has 2 aims. The first is to introduce the concept of rehabilitative ultrasound imaging (RUSI), provide a definition of the scope of this emerging tool in regard to the physical therapy profession, and describe how this relates to the larger field of medical ultrasound imaging. The second aim is to provide an overview of basic ultrasound imaging and instrumentation principles, including an understanding of the various modes and applications of the technology with respect to neuromusculoskeletal rehabilitation and in relation to other common imaging modalities.

Rehabilitative ultrasound imaging of pelvic floor muscle function

This commentary provides an overview of the current concepts and evidence related to rehabilitative ultrasound imaging of pelvic floor (levator ani) function. As this is an emerging topic, the goal is to provide a basic understanding of ultrasound imaging applications related to levator ani function: the available quantitative and qualitative information, the limitations, as well as how ultrasound imaging can be incorporated as a form of biofeedback during rehabilitation. Furthermore, as the ability to compile and compare existing evidence depends on the degree of similarity in methodology by investigators, this commentary highlights points of consideration and provides guidelines, as well as an agenda, for future investigation.

Lumbopelvic dysfunction and stress urinary incontinence: a case report applying rehabilitative ultrasound imaging

STUDY DESIGN

Case report.

BACKGROUND

It has been suggested that altered neuromuscular control of the transversus abdominis and pelvic floor muscles may contribute to sacroiliac joint (SIJ) region pain and stress urinary incontinence. There are limited examples describing the evaluation and management of individuals with both SIJ region pain and stress urinary incontinence in the literature. This case report describes a patient with both conditions and details the integration of rehabilitative ultrasound imaging (RUSI) during physical therapy evaluation. 6

CASE DESCRIPTION

A 35-year-old female soldier presented with a 6-week history of left buttock pain and 4-year history of stress urinary incontinence during activities that involved running, jumping, and fast walking. RUSI was used to supplement the physical assessment process, revealing altered motor control strategies of the transversus abdominis and pelvic floor muscles, and as a form of biofeedback during the rehabilitation process.

OUTCOMES

After completing a rehabilitation program that incorporated principles of lumbar stabilization and pelvic floor muscle re-education, this patient was able to complete all physical activities in basic combat training without SIJ region pain or urinary leakage.

DISCUSSION

This case demonstrates the importance of considering pelvic floor muscle dysfunction and training in a patient with primary complaints of SIJ region pain. It also highlights the potential role of RUSI as both an evaluation and biofeedback tool for the deep abdominal and pelvic floor muscles.

Displacement and recovery of the vesical neck position during pregnancy and after childbirth

AIMS

(i) To describe the displacement and recovery of the vesical neck position during pregnancy and after childbirth and (ii) to discriminate between compliance of the vesical neck supporting structures with and without pelvic floor contraction.

METHODS

We focussed on the biomechanical properties of the vesical neck supporting structures during pregnancy and after childbirth by calculating the compliance and the hysteresis as a result from of abdominal pressure measurements and simultaneous perineal ultrasound.

RESULTS

This study shows that compliance of the supporting structures remains relatively constant during pregnancy and returns to normal values 6 months after childbirth. Hysteresis, however, showed an increase after childbirth, persisting at least until 6 months post partum.

CONCLUSIONS

Vaginal delivery may stretch and or load beyond the physiological properties of the pelvic floor tissue and in this way may lead to irreversible changes in tissue properties which play an important role in the urethral support continence mechanism.

Ex vivo biomechanical properties of the female urethra in a rat model of birth trauma

Stress urinary incontinence (SUI) is the involuntary release of urine during sudden increases in abdominal pressures. SUI is common in women after vaginal delivery or pelvic trauma and may alter the biomechanical properties of the urethra. Thus we hypothesize that injury due to vaginal distension (VD) decreases urethral basal tone and passive stiffness. This study aimed to assess the biomechanical properties of the urethra after VD in the baseline state, where basal muscle tone and extracellular matrix (ECM) are present, and in the passive state, where inactive muscle and ECM are present. Female rat urethras were isolated in a rat model of acute SUI induced by simulated birth trauma. Our established ex vivo system was utilized, wherein we applied intraluminal static pressures ranging from 0 to 20 mmHg. Outer diameter was measured via a laser micrometer. Measurements were recorded via computer. Urethral thickness was assessed histologically. Stress-strain responses of the urethra were altered by VD. Quantification of biomechanical parameters indicated that VD decreased baseline stiffness. The passive peak incremental elastic modulus of the distal segment in VD urethras was less than for controls (1.84 ± 0.67 vs. 1.19 ± 0.70 × 106 dyne/cm2, respectively; P = 0.016). An increase was noted in passive low-pressure compliance values in proximal VD urethras compared with controls (9.44 ± 2.43 vs. 4.62 ± 0.60 mmHg−1, respectively; P = 0.04). Biomechanical analyses suggest that VD alters urethral basal tone, proximal urethral compliance, and distal stiffness. Lack of basal smooth muscle tone, in combination with these changes in the proximal and distal urethra, may contribute to SUI induced by VD.

A contextual model of pelvic floor muscle defects in female stress urinary incontinence: a rationale for physiotherapy treatment

On the basis of the current literature, we describe a model of structural defects in stress urinary incontinence (SUI) and how physiotherapy for SUI can affect each component of the model with reference to the relevant anatomy and pathophysiology. This model of SUI involves four primary structural defects: (1) increased tonic stress on the pelvic fascia due to pelvic floor muscle (PFM) tears; (2) fascial tearing due to PFM denervation; (3) fascial weakness resulting from tears; and (4) inefficient PFM contraction due to altered motor control. These four components interact to collectively weaken urethral closure and allow urine leakage under conditions of increased intra-abdominal pressure. Physiotherapy can strengthen the PFM and may improve the efficiency and/or timing of PFM contractions to reduce or eliminate SUI. It is worthwhile for motivated women with SUI to try PFM exercise therapy as a first approach to treatment. Women need to be individually instructed to ensure that they correctly perform PFM contractions and that they can monitor their own performance. Long-term, high-intensity exercise, including home exercise, is necessary to achieve maximum effect. Under these conditions the improvement in urinary continence with PFM exercise can be complete and enduring.

Postural activity of the pelvic floor muscles is delayed during rapid arm movements in women with stress urinary incontinence

The aim of this study was to determine whether postural activity of the pelvic floor (PF) and abdominal muscles differs between continent and incontinent women during rapid arm movements that present a postural challenge to the trunk. A further aim was to study the effect of bladder filling. Electromyographic activity (EMG) of the PF, abdominal, erector spinae (ES), and deltoid muscles was recorded with surface electrodes. During rapid shoulder flexion and extension, PF EMG increased before that of the deltoid in continent women, but after the deltoid in incontinent women (p = 0.002). In many incontinent women, PF EMG decreased before the postural activation. Although delayed, postural PF EMG amplitude was greater in women with incontinence (p = 0.010). In both groups, PF EMG decreased and abdominal and ES EMG increased when the bladder was moderately full. These findings would be expected to have negative consequences for continence and lumbopelvic stability in women with incontinence.

Electromyography of pelvic floor muscles

Pelvic floor muscles (PFM) are intimately involved in function of lower urinary tract, the anorectum and sexual functions, therefore their neural control transcends the primarily important somatic innervation of striated muscle, as they are directly involved in "visceral activity". Neural control of pelvic organs is affected by a unique co-ordination of somatic and autonomic motor nervous systems. Visceral and somatic sensory fibres supply sensory information from pelvic organs; their input influences through central integrative mechanisms also pelvic floor muscle activity. Anatomically, somatic afferent and efferent nerves of the sacral cord segments, reflexly integrated at the spinal cord and brainstem level, conduct neural control of PFM. The inputs from several higher centres influence the complex reflex control and are decisive for voluntary control, and for socially adapted behaviour related to excretory functions.

Comparison of transperineal and transabdominal ultrasound in the assessment of voluntary pelvic floor muscle contractions and functional manoeuvres in continent and incontinent women

Transperineal (TP) and transabdominal (TA) ultrasounds were used to assess bladder neck (TP) and bladder base (TA) movement during voluntary pelvic floor muscle (PFM) contraction and functional tasks. A sonographer assessed 60 asymptomatic (30 nulliparous, 30 parous) and 60 incontinent (30 stress, 30 urge) women with a mean age of 43 (SD=7) years, BMI of 24 (SD=4) kg m2 and a median parity of 2 (range, 0-5), using both ultrasound methods. The mean of three measurements for bladder neck and bladder base (sagittal view) movement for each task was assessed for differences between the groups. There were no differences in bladder neck (p=0.096) or bladder base (p=0.112) movement between the four groups during voluntary PFM contraction but significant differences in bladder neck (p<0.004) and a trend towards differences in bladder base (p=0.068) movement during Valsalva and abdominal curl manoeuvre. During PFM contraction, there was a strong trend for the continent women to have greater bladder neck elevation (p=0.051), but no difference in bladder base movement (p=0.300), when compared to the incontinent women. The incontinent women demonstrated increased bladder neck descent during Valsalva and abdominal curl (p<0.001) and bladder base descent during Valsalva (p=0.021). The differences between the groups were more marked during functional activities, suggesting that comprehensive assessment of the PFM should include functional activities as well as voluntary PFM contractions. TP ultrasound was more reliable and takes measures from a bony landmark when compared to TA ultrasound, which lacks a reference point for measurements. TA ultrasound is less suitable for PFM measures during functional manoeuvres and comparisons between subjects. Few subjects were overweight so the results may not be valid in an obese population.

2D Ultrasound image processing in identifying responses of urogenital structures to pelvic floor muscle activity

We present the analysis of sequences of voluntarily and reflexly generated pelvic floor muscle (PFM) contractions on the urethra, vagina, and rectum. A succession of observations were taken of perineal ultrasound at a frequency of 3.5 MHz imaging using a curved linear array probe in the sagittal plane and the videos captured and stored. An edge extraction algorithm was used to outline the coordinates of the symphysis pubis, urethra, and rectum interfaces on a frame-by-frame basis for sequences of 10-20 s. During each PFM contraction, the trajectory of the boundary of each structure was evaluated, colour coded, and overlaid to characterize the sequential history of the ensuing movement. The resulting image analysis was focused to reveal the anatomical displacement of the urogenital structures, which enables the evaluation of their biomechanical parameters in terms of displacement, velocity, and acceleration at any point in time. On the basis of these observations, the biomechanical mechanisms of pelvic floor muscle responses to voluntary and reflex contractions can be identified. It is concluded that a considerable amount of new, potentially useful clinical information can be revealed from video recordings of perineal ultrasound using the image analysis approach proposed.

Pelvic organ prolapse and the lower urinary tract: the relationship of vaginal prolapse to stress urinary incontinence

Vaginal prolapse and urinary incontinence frequently coexist. Rather than having a cause-and-effect relationship, these two common problems share etiologic factors. Specific tissue and functional deficiencies resulting in prolapse also are significant contributors to lower urinary tract symptoms, particularly stress urinary incontinence. This article reviews this relationship, the etiologic factors, and aspects of the clinical evaluation of the patient with prolapse and stress urinary incontinence.

[A new approach to the transvaginal needle suspension technique after Raz. Technique and long-term results]

AIM

Our aim is to describe the surgical technique and to present a long-term evaluation of the results.

MATERIALS AND METHODS

A total of 53 patients with stress incontinence underwent a Raz transvaginal needle suspension operation with the introduction of a polypropylene mesh strip (15x1.5-2 cm) pulled under the suspension threads. The suspension threads occur on the endopelvic fascia in order to support the bladder neck and to permit the function of the polypropylene mesh strip, which, however, does not take part in supporting the bladder neck. The same urologist carried out 53 consecutive operations with clinical evaluation at 6 months, 1 and 5 years after surgery.

RESULTS

After 6 months, 51 of the patients (96.2%) reported remaining dry after increasing intra-abdominal pressure. Two (3.7%) still had stress incontinence symptoms. After 1 and 5 years, 47 (88.6%) were dry and urinated normally, with spontaneous disappearance of nightly enuresis in two and surgery for subvesicular obstruction in one.

CONCLUSIONS

The introduction of a polypropylene mesh strip in the suspension threads in cases using the trasvaginal suspension technique has good, long-term results for the treatment of patients with stress incontinence.

Elastolytic activity in women with stress urinary incontinence and pelvic organ prolapse

AIMS

Weakening of pelvic supportive tissues is thought to be a contributing etiology in female pelvic floor disorders such as stress urinary incontinence and/or pelvic organ prolapse (SUI/POP). Since elastin modulates the mechanical properties of supportive tissues, we examined elastase activity in vaginal tissue from women with pelvic floor dysfunction compared to asymptomatic controls, by comparing overall elastase activity, human neutrophil elastase, cathepsin K, and alpha-1 antitrypsin (a serine protease inhibitor) mRNA and protein levels.

METHODS

Full-thickness peri-urethral vaginal wall tissues were collected from age and menstrual-phase matched SUI/POP and control women at the time of pelvic surgery. Elastolytic activity in the homogenized tissue was determined by the generation of amino groups from succinylated elastin. To quantify mRNA levels of each protein, quantitative competitive-PCR and confirmatory Western blot analyses were performed on the samples for human neutrophil elastase, cathepsin K, and alpha-1 antitrypsin.

RESULTS

The mean elastolytic activity in vaginal tissues from the SUI/POP group was similar to that in the control group. With respect to the proteolytic enzymes, neither human neutrophil elastase nor cathepsin K differed between the two groups. However, alpha-1 antitrypsin mRNA and protein levels were significantly decreased in tissues from affected women.

CONCLUSIONS

A significant decrease in alpha-1 antitrypsin expression was seen in tissues from women with SUI/POP compared to controls. This data suggest that altered elastin metabolism may contribute to the connective tissue alterations observed in pelvic floor dysfunction. Future investigations are warranted to help define the role of elastin turnover in pelvic floor dysfunction.