Pathophysiology of adult urinary incontinence

Application of perineal ultrasound measurement and urodynamic study in the diagnosis and typing of stress urinary incontinence ultrasound and urodynamic study

AIMS

To explore the value of perineal ultrasound and urodynamic study in the clinical diagnosis with the morphological and functional changes and evaluation of clinical type in female patients with stress urinary incontinence (SUI).

METHODS

The records of 64 female patients with SUI were reviewed. Fifty females with urinary frequency but with no SUI symptoms served as controls. All of them underwent ultrasound and urodynamic measurement. P<0.05 was considered statistically significant.

RESULTS

The maximum flow rate (Q max) was significantly higher in the patients than in the control group, but the maximal urethral pressure (MUP), maximal urethral closing pressure (MUCP) and functional urethral length (FUL) were significantly lower than in the control group. Ultrasound measurements showed that the rotation angle and movement of urethrovesical junction, funneling of bladder neck and posterior urethrovesical angle (PUVA) at rest and during straining were greater in patients than in the control group. Patients with higher abdominal leak point pressure (ALPP) had higher maximal urethral closing pressure (MUCP), greater rotation angle and movement of urethrovesical junction. Patients with higher MUCP had higher ALPP, greater rotation angle and movement of urethrovesical junction.

CONCLUSIONS

The urodynamic study and perineal ultrasound have a great significance in the diagnosis and typing of SUI.

Long-term structural and functional effects of autologous muscle precursor cell therapy in a nonhuman primate model of urinary sphincter deficiency

PURPOSE

We measured the long-term efficacy of autologous muscle precursor cell therapy in premenopausal female nonhuman primates with sustained urinary sphincter deficiency.

MATERIALS AND METHODS

Urinary sphincter deficiency was created in adult premenopausal female cynomolgus monkeys by selectively cauterizing and then transecting the pudendal innervation to the sphincter complex. The monkeys were then treated (18) or not treated (18) with intra-urinary sphincter injections of 5 million autologous green fluorescent protein labeled skeletal muscle precursor cells. Four untreated, uninjured monkeys served as controls. Maximal urethral pressure measurement and corresponding histological analysis of the structural and cellular components of the sphincter complex were performed up to 12 months after injection.

RESULTS

Cell treatment produced sustained (12 months) increases in resting, somatic nerve stimulated and adrenergic nerve stimulated maximal urethral pressure, and a greater percent of sphincter area occupied by muscle as well as a decrease in the sphincter area occupied by collagen compared to the untreated group (each p>0.05). These results were within control values (each p>0.05). By 3 months after injection green fluorescent protein positive cells were found in the skeletal muscle layer, expressing desmin and connexin-43, and in the smooth muscle layer, expressing α-smooth muscle actin and connexin-43, and they were incorporated into the subendothelial vasculature, expressing Von Willebrand factor. Cell injected sphincter tissue contained a mixture of green fluorescent protein positive cells and predominantly green fluorescent protein negative cells.

CONCLUSIONS

Injected skeletal muscle progenitor cells incorporated into the injured sphincter complex resulted in long-term structural and functional restoration of the injured sphincter complex in this nonhuman primate model.

A nonhuman primate model of stable urinary sphincter deficiency

PURPOSE

The pathophysiology of urinary sphincter deficiency in women remains incompletely understood and current treatment options have limitations. Female nonhuman primates may represent a relevant animal model for studies of pathophysiology and treatment interventions because of their human-like reproductive and age associated stages of life (premenopause, perimenopause and postmenopause), lower urinary tract structure and bipedal posture. We developed and characterized a nonhuman primate model of defined injury to the urethral sphincter complex.

MATERIALS AND METHODS

We used 22 adult female cynomolgus monkeys in which injury to the sphincter complex was created by cauterizing and then transecting its pudendal innervation. Urodynamic studies were performed before and during pudendal and hypogastric nerve stimulation at baseline, and 3, 6 and 12 months after injury. We also analyzed sphincter structure in vivo by cystourethrography, and ex vivo by quantitative histology and immunohistochemistry at these time points.

RESULTS

Injury produced a 47% to 50% decrease in maximal urethral pressure (vs baseline p <0.05). It also abolished the increase in maximal urethral pressure in response to pudendal and hypogastric nerve stimulation (vs baseline p >0.05), which persisted more than 12 months after injury. Urodynamic changes were consistent with decreased skeletal and smooth muscle content, decreased nerve responses and an associated decrease in somatic and adrenergic innervation in the sphincter complex.

CONCLUSIONS

These structural and urodynamic changes are consistent with those in patients with stress urinary incontinence. They support the usefulness of nonhuman primates as translatable surrogates for pathophysiological studies of urinary sphincter deficiency and testing novel therapies for that condition.

Novel insight into the dynamics of male pelvic floor contractions through transperineal ultrasound imaging

PURPOSE

Transperineal ultrasound imaging enables the minimally invasive assessment of pelvic floor muscle function. Although commonly used in women, the approach has rarely been reported in men. This approach has advantages because the midsagittal view visualizes a bony landmark and the entire urethral length. This allows investigation of the displacement of multiple points along the urethra and the unique mechanical actions of multiple muscles that could influence continence. We used a new transperineal ultrasound technique to compare the relative displacement of urethrovesical junction, anorectal junction and distal urethra during voluntary pelvic floor muscle contractions in continent men.

MATERIALS AND METHODS

We performed measurement and comparison of urethral displacement at specific urethral regions in 10 continent men (age range 28 to 41 years). Measures made on 2-dimensional midsagittal plane ultrasound images included the displacements of specific points along the urethra. Anatomical considerations suggest that these are caused by contraction of the levator ani, striated urethral sphincter and bulbocavernosus muscles. Pearson's correlation coefficient was used to investigate the relationship between displacements of pairs of points.

RESULTS

Data show individual variation in displacement of the distal urethra (striated urethral sphincter contraction) and urethrovesical junction (levator ani contraction). A strong inverse linear relationship (0.723) between displacements of these points indicates 2 alternative strategies of urethral movement.

CONCLUSIONS

Transperineal ultrasound imaging allows the simultaneous investigation of multiple pelvic floor muscles by measuring urethral displacement. The data provide evidence of different but coordinated strategies of urethral displacement in men.

Does childbirth alter the reflex pelvic floor response to coughing?

OBJECTIVE

To determine the prevalence of and to quantify the effect of reflex pelvic floor activation on coughing in nulliparous pregnant women, and to assess peripartal changes and any association with stress urinary incontinence.

METHODS

Between April 2008 and March 2010, 131 nulliparous pregnant women were recruited from an antenatal clinic. All participants were interviewed and underwent four-dimensional translabial ultrasound examination at antepartum (35.8 (mean) weeks' gestation) and postpartum (4.6 (mean) months) visits. Four-dimensional ultrasound volume datasets of the pelvic floor during coughs were obtained at a minimum frame rate of 16 Hz, using a 10° volume acquisition angle. To quantify a reflex levator contraction we measured the midsagittal hiatal diameter at multiple time points. Levator integrity was determined using tomographic ultrasound imaging.

RESULTS

From 131 women recruited, 47 datasets were technically suboptimal, leaving 84. There was a visible pelvic floor reflex in 82 (98%) cases. At the postpartum visit this was reduced to 63/84, i.e. 75% (P < 0.001). The magnitude of a reflex contraction was markedly reduced postpartum, from 4.8 mm to 2.0 mm (P < 0.001), and this effect was associated with delivery mode (P = 0.042). There was a trend towards an association between lower reflex contraction magnitude and stress incontinence (0.87 ± 3.18 mm vs. 2.36 ± 3.5 mm; P = 0.08) at the postpartum follow-up visit.

CONCLUSIONS

Pelvic floor reflexes are altered by childbirth. This alteration may be associated with vaginal delivery. Reflex magnitude may be associated with postpartum stress urinary incontinence. The clinical significance of this finding is uncertain.

Is tissue engineering and biomaterials the future for lower urinary tract dysfunction (LUTD)/pelvic organ prolapse (POP)?

The fields of tissue engineering and regenerative medicine have seen major advances over the span of the past two decades, with biomaterials playing a central role. Although the term "regenerative medicine" has been applied to encompass most fields of medicine, in fact urology has been one of the most progressive. Many urological applications have been investigated over the past decades, with the culmination of these technologies in the introduction of the first laboratory-produced organ to be placed in a human body.1 With the quality of life issues associated with urinary incontinence, there is a strong driver to identify and introduce new technologies and the potential exists for further major advancements from regenerative medicine approaches using biomaterials, cells or a combination of both. A central question is why use biomaterials? The answer rests on the need to make up for inadequate or lack of autologous tissue, to decrease morbidity and to improve long-term efficacy. Thus, the ideal biomaterial needs to meet the following criteria: (1) Provide mechanical and structural support, (2) Maintain compliance and be biocompatible with surrounding tissues, and (3) Be "fit for purpose" by meeting specific application needs ranging from static support to bioactive cell signaling. In essence, this represents a wide range of biomaterials with a spectrum of potential applications, from use as a supportive or bulking implant alone, to implanted biomaterials that promote integration and eventual replacement by infiltrating host cells, or scaffolds pre-seeded with cells prior to implant. In this review we shall discuss the structural versus the integrative uses of biomaterials by referring to two key areas in urology of (1) pelvic organ support for prolapse and stress urinary incontinence, and (2) bladder replacement/augmentation.

Repair of recurrent prolapse

The pathogenesis of prolapse and the requirements for a successful surgical outcome vary from one person to another. The importance of traditional risk factors is questionable, but failed previous repair is definitely an adverse prognosticator. An ideal operation should re-attach apical support to the pelvic skeleton, restore integrity within anterior and posterior suspensory hammocks and re-distribute some of the expulsive load back onto the pelvic diaphragm. Reasons for failure are best analysed by location; recurrence within the operated compartment should also be distinguished from recurrence in a different compartment. There is no all-encompassing secret to re-operating on recurrent prolapse. Success depends on sound strategic planning and using tactics to negate the greater technical difficulty and reduced collagen strength in women with prior operative failure. If an augmented repair is to be carried out, choice of biomaterials must reflect surgical objectives, movement dynamics and functional anatomy at the intended implantation site.

Breathing with the pelvic floor? Correlation of pelvic floor muscle function and expiratory flows in healthy young nulliparous women

INTRODUCTION AND HYPOTHESIS

The aim of this cross-sectional study was to determine correlations between pelvic floor muscle (PFM) function and expiratory function in healthy young nulliparous women.

METHODS

In 40 volunteers, PFM function was assessed by vaginal palpation. Forced expiration patterns were evaluated visually and by palpation of the suprapubic insertion region of the anterolateral abdominal muscles. Forced vital capacity (FVC) and forced expiratory flows (FEF) were determined by spirometry.

RESULTS

Incremental positive correlation was found between voluntary PFM contraction strength and forced expiratory flow at 25%, 50% and 75% (FEF(25%), FEF(50%), FEF(75%)) of the FVC, respectively. Positive correlation was also found between PFM contraction strength and forced expired volume in 1 s (FEV(1)). No correlation was found between PFM contraction strength and FVC or peak expiratory flow (PEF).

CONCLUSIONS

Despite some limitations of this study, the observed correlation between PFM contraction strength and forced expiratory flows may serve as theoretical background for a potential role of coordinated abdominal and PFM training in diseases with expiratory flow limitations.

Stem cells for stress urinary incontinence: the adipose promise

Stress urinary incontinence (SUI), the most common type of incontinence in women, is a frequent and costly ailment responsible for an alteration in the quality of life. Although medical treatment gives some rather deceiving results, surgical techniques that include colposuspension or tension-free vaginal tape, employed in cases of urethral support defect, give a 5-year cure rate of more than 80%. However, these techniques could lead to complications or recurrence of symptoms. Recently, the initiation of urethral cell therapy has been undertaken by doctors and researchers. One principal source of autologous adult stem cells is generally used: muscle precursor cells (MPCs) which are the progenitors of skeletal muscle cells. Recently, a few research groups have shown interest in the MPCs and their potential for the treatment of urinary incontinence. However, using MPCs or fibroblasts isolated from a striated muscle biopsy could be questionable on several points. One of them is the in vitro cultivation of cells, which raises issues over the potential cost of the technique. Besides, numerous studies have shown the multipotent or even the pluripotent nature of stromal vascular fraction (SVF) or adipose-derived stem cells (ASCs) from adipose tissue. These cells are capable of acquiring in vitro many different phenotypes. Furthermore, recent animal studies have highlighted the potential interest of SVF cells or ASCs in cell therapy, in particular for mesodermal tissue repair and revascularization. Moreover, the potential interest of SVF cells or ASCs for the treatment of urinary incontinence in women is supported by many other characteristics of these cells that are discussed here. Because access to these cells via lipoaspiration is simple, and because they are found in very large numbers in adipose tissue, their future potential as a stem cell reservoir for use in urethral or other types of cell therapy is enormous.

The role of calpain-calpastatin system in the development of stress urinary incontinence

INTRODUCTION AND HYPOTHESIS

The objective of this study is to investigate the expression of calpain-1, calpain-2, and calpastatin in the human periurethral vaginal tissues and to show the potential link between calpain system and stress urinary incontinence (SUI).

METHODS

The periurethral vaginal tissues of 39 women with SUI and 31 women without SUI were collected to detect the expressions of calpains and calpastatin by using semi-quantitative competitive reverse transcription-polymerase chain reaction and Western blotting.

RESULTS

There were no significant differences on the expressions of calpain-1 at the levels of messenger RNA (mRNA) and protein in both groups (P > 0.05), but the patients with SUI had significantly higher levels of calpain-2 mRNA and protein than the control (P < 0.05); and the mRNA expressions of calpastatin in women with SUI were significantly higher than the control (P < 0.05), while the protein expressions were significantly lower when compared to the control (P < 0.01).

CONCLUSIONS

Overexpression of calpain-2 and low expression of calpastatin may involve in the pathological development of SUI.

Improvement of quality of life, anxiety and depression after surgery in patients with stress urinary incontinence: results of a longitudinal short-term follow-up

Objective

The objective of this study was to compare the effect of incontinence surgery and pelvic floor training on quality of life (QOL), anxiety and depression in patients with stress urinary incontinence (SUI).

Methods

In a prospective longitudinal study, females with proven SUI were asked to complete a set of standardized questionnaires (sociodemographic data sheet, FACT-G, I-QOL, HADS) before and eight weeks after treatment. The comparison groups consisted of a surgical treatment group and a conservative group that underwent supervised pelvic floor training for eight weeks.

Results

From the 67 female patients included in the study a number of 53 patients completed both assessment time points (mean age 57.4, mean years of SUI 7.6). The surgical treatment group consisted of 32 patients of which 21 patients received a modified Burch colposuspension and 11 patients a tension-free mid-urethral tape suspension. The 21 patients in the conservative group attended eight once-weekly supervised pelvic floor training sessions.

After treatment the surgical intervention group showed a significantly higher improvement of QOL (FACT-G and I-QOL) and anxiety (HADS) than the pelvic floor training group.

Conclusion

For female patients with SUI surgery yielded a better outcome than pelvic floor training with regard to quality of life and anxiety.

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.

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.

The role of neutrophil elastase in elastin metabolism of pelvic tissues from women with stress urinary incontinence

OBJECTIVE

Altered elastin metabolism is implicated in pelvic floor disorders. We studied neutrophil elastase (NE) and matrix metalloproteinase (MMP) activities in vaginal tissues from premenopausal women with stress urinary incontinence (SUI).

METHODS

Elastase and NE activities in vaginal tissues were assessed. Protein and mRNA expressions were determined by RT-PCR and Western blot. Total elastin and collagen contents were evaluated. To compare the relative elastolytic effect of NE and MMP-2, we used their respective antibodies to immunoprecipitate these proteins from vaginal fibroblast extracts prior to assessing elastase activity.

RESULTS

Elastase activity in vaginal wall tissues was significantly higher in the secretory compared to the proliferative phase. NE mRNA and protein expressions were similar between control and SUI tissues from the secretory phase. However, NE activity in the SUI tissues was higher compared to control tissues. The mRNA expression of alpha-1 antitrypsin (ATT) was higher in control tissues from the proliferative phase compared to those from the secretory phase, while no difference was observed in SUI tissues between either phase. Protein expression of the active form of ATT was decreased in SUI tissues compared to controls during the secretory phase. Anti-NE antibody reduced total elastase activity by 60-70%, compared to less than 20% reduction with anti-MMP-2 antibody.

CONCLUSION

During the secretory phase, elastolytic activity is increased in pelvic tissues from women with SUI, through an increase in NE activity and a concurrent decrease in ATT expression. The serine protease, NE, appears to be a more significant modulator of elastase activity compared to MMP-2.

Functional anatomy of the female pelvic floor

The anatomic structures in the female that prevent incontinence and genital organ prolapse on increases in abdominal pressure during daily activities include sphincteric and supportive systems. In the urethra, the action of the vesical neck and urethral sphincteric mechanisms maintains urethral closure pressure above bladder pressure. Decreases in the number of striated muscle fibers of the sphincter occur with age and parity. A supportive hammock under the urethra and vesical neck provides a firm backstop against which the urethra is compressed during increases in abdominal pressure to maintain urethral closure pressures above the rapidly increasing bladder pressure. This supporting layer consists of the anterior vaginal wall and the connective tissue that attaches it to the pelvic bones through the pubovaginal portion of the levator ani muscle, and the uterosacral and cardinal ligaments comprising the tendinous arch of the pelvic fascia. At rest the levator ani maintains closure of the urogenital hiatus. They are additionally recruited to maintain hiatal closure in the face of inertial loads related to visceral accelerations as well as abdominal pressurization in daily activities involving recruitment of the abdominal wall musculature and diaphragm. Vaginal birth is associated with an increased risk of levator ani defects, as well as genital organ prolapse and urinary incontinence. Computer models indicate that vaginal birth places the levator ani under tissue stretch ratios of up to 3.3 and the pudendal nerve under strains of up to 33%, respectively. Research is needed to better identify the pathomechanics of these conditions.

Kit-positive interstitial cells in the rabbit urethra: structural relationships with nerves and smooth muscle

OBJECTIVE

To identify interstitial cells (ICs) in the wall of the rabbit urethra using antibodies to the Kit receptor, and to examine their location, morphology and relationship with nerves and smooth muscle cells (SMCs), as studies of enzymatically isolated cells from the rabbit urethra have established that there are specialized cells that show spontaneous electrical activity and have morphological properties of ICs.

MATERIALS AND METHODS

Urethral tissues from rabbits were fixed, labelled with antibodies and examined with confocal microscopy. Some specimens were embedded in paraffin wax and processed for histology. Histological sections from the most proximal third and mid-third region of rabbit urethra were stained with Masson's Trichrome to show their cellular arrangement.

RESULTS

Sections from both regions had outer longitudinal and inner circular layers of SM, and a lamina propria containing connective tissue and blood vessels; the lumen was lined with urothelial cells. The mid-third region had a more developed circular SM layer than the most-proximal samples, and had extensive inner longitudinal SM bundles in the lamina propria. Labelling with anti-Kit revealed immunopositive cells within the wall of the rabbit urethra, in the circular and longitudinal layers of the muscularis. Double-labelling with an antibody to SM myosin showed Kit-positive cells on the boundary of the SM bundles, orientated parallel to the axis of the bundles. Others were in spaces between the bundles and often made contact with each other. Kit-positive cells were either elongated, with several lateral branches, or stellate with branches coming from a central soma. Similar cells could be labelled with vimentin antibodies. Their relationship with intramural nerves was examined by double immunostaining with an anti-neurofilament antibody. There were frequent points of contact between Kit-positive cells and nerves, with similar findings in specimens double-immunostained with anti-neuronal nitric oxide synthase (nNOS).

CONCLUSION

Kit-positive ICs were found within the SM layers of the rabbit urethra, in association with nerves, on the edge of SM bundles and in the interbundle spaces. The contact with nNOS-containing neurones might imply participation in the nitrergic inhibitory neurotransmission of the urethra.

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.

Reliability of speed of contraction and endurance dynamometric measurements of the pelvic floor musculature in stress incontinent parous women

AIMS

To evaluate the test-retest reliability of dynamometric measurements of the pelvic floor muscles (PFM) during speed and endurance tests.

METHODS

Nineteen parous women suffering from stress urinary incontinence (SUI) participated in the study. Two PFM evaluation sessions were conducted using the dynamometric speculum. For the speed test, the women were instructed to contract maximally and relax as quickly as possible during a 15-s test period. The speed of contraction was quantified by the rate of force development of the first contraction and the number of contractions performed. The maximal strength value attained during the speed test was also extracted from the curves. For the endurance test, the subjects were asked to maintain a maximal contraction for 90 s. The normalized area under the force curve was utilized as the endurance parameter. The reliability of the data was evaluated using the generalizability theory. Two reliability estimates were calculated, the dependability indices (Phi) and the standard error of measurement (SEM), for one measurement session involving one trial.

RESULTS

The indices of dependability obtained indicate that the reliability of the speed of contraction and endurance parameters are good (Phi=0.79-0.92). The corresponding SEMs were 1.39 N/s, 1 contraction, 1.00 N, and 298%*s for the rate of force development, number of contractions, maximal strength and normalized area, respectively.

CONCLUSION

This study indicates that the speed of contraction and endurance parameters possess good test-retest reliability. The inclusion of these parameters in the PFM assessment is therefore highly recommended for assessing changes in PFM in incontinent women.

Prevalence of diastasis recti abdominis in a urogynecological patient population

A urogynecologist's examination typically includes assessment of the abdominal musculature, including the determination of whether a diastasis recti abdominis (DRA) is present. The purposes of the current study were to examine the (1) prevalence of DRA in a urogynecological population, (2) differences in select characteristics of patients with and without DRA, and (3) relationship of DRA to support-related pelvic floor dysfunction diagnoses. A retrospective chart review was conducted by an independent examiner. Fifty-two percent of the patients examined presented with DRA. Patients with DRA were older, reported higher gravity and parity, and had weaker pelvic floor muscles than patients without DRA. Sixty-six percent of all the patients with DRA had at least one support-related pelvic floor dysfunction (SPFD) diagnosis. There was a relationship between the presence of DRA and the SPFD diagnoses of stress urinary incontinence, fecal incontinence, and pelvic organ prolapse.

Differences in muscle activation patterns during pelvic floor muscle contraction and Valsalva maneuver

AIMS

To investigate the different muscle activation patterns around the abdomino-pelvic cavity in continent women and their effect on pressure generation during a correct pelvic floor muscle (PFM) contraction and a Valsalva maneuver.

METHODS

Thirteen continent women were assessed. Abdominal, chest wall, and PFM activity and vaginal and intra-abdominal pressure (IAP), were recorded during two tasks: PFM contraction and Valsalva whilst bladder base position was monitored on trans-abdominal ultrasound. A correct PFM contraction was defined as one that resulted in bladder base elevation and a Valsalva resulted in bladder base depression.

RESULTS

Comparison of the mean of the normalized EMG activity of all the individual muscle groups was significantly different between PFM contraction and Valsalva (P = 0.04). During a correct PFM contraction, the PFM were more active than during Valsalva (P = 0.001). During Valsalva, all the abdominal muscles (IO (P = 0.006), EO (P < 0.001), RA (P = 0.011)), and the chest wall (P < 0.001) were more active than during PFM contraction. The change in IAP was greater during Valsalva (P = 0.001) but there was no difference in the change in vaginal pressure between PFM contraction and Valsalva (P = 0.971).

CONCLUSIONS

This study demonstrates a difference in muscle activation patterns between a correct PFM contraction and Valsalva maneuver. It is important to include assessment of the abdominal wall, chest wall, and respiration in the clinical evaluation of women performing PFM exercises as abdominal wall bracing combined with an increase in chest wall activity may cause rises in IAP and PFM descent.

Women's health 18 years after rupture of the anal sphincter during childbirth: II. Urinary incontinence, sexual function, and physical and mental health

OBJECTIVE

We studied maternal health 18 years postpartum in women having sustained an anal sphincter tear and controls.

STUDY DESIGN

We assessed symptoms with the short form of the urogenital distress inventory, the female sexual function index, and physical and mental health with the Short Form-12 summary scales.

RESULTS

Women with a sphincter tear had no increased risk of urinary symptoms (54 of 251, 22%, versus 51 of 273, 19%, risk ratio 1.2, 95% confidence interval 0.8 to 1.6) or sexual symptoms (84 of 223, 38%, versus 90 of 230, 39%, risk ratio 1.0, 95% confidence interval 0.8 to 1.2). Their physical health was also similar to controls (mean score +/- SD, 47 +/- 7 versus 47 +/- 6), whereas their mental health was slightly lower (score 45 +/- 6 versus 46 +/- 6, difference 1, 95% confidence interval 0 to 2, P = .05).

CONCLUSION

Women who sustained an anal sphincter tear have no more urinary or sexual symptoms 18 years after delivery.

What do we know about duloxetine's mode of action? Evidence from animals to humans

The serotonin (5-hydroxytryptamine [5-HT]) and noradrenalin (NA) reuptake inhibitor duloxetine is currently the only widely approved pharmacological treatment option for women with stress urinary incontinence (SUI). The rationale for employing duloxetine in SUI is based on the role of 5-HT and NA in the neurological control of the lower urinary tract. Animal studies have shown that duloxetine increases the concentration of 5-HT and NA in the sacral spinal cord, thereby facilitating an increased activity of the external urethral sphincter (rhabdosphincter) and preventing urine leakage during the storage phase of the micturition cycle. Importantly, 5-HT and NA exert only a modulatory effect as they are not able to directly excite motor neurons. Glutamate is the key descending neurotransmitter and can be considered as the "on/off" switch for micturition. In the absence of glutamate, no rhabdosphincter activity is observed, irrespective of the presence of 5-HT and NA. Hence, duloxetine enhances sphincter activity during urine storage when glutamate is released but allows complete relaxation of the rhabdosphincter once glutamate release is inhibited during the voiding phase. The efficacy of duloxetine for treating women with SUI, as shown in several double-blind, placebo-controlled randomised clinical trials, has suggested a similar mode of action, although no direct evidence for this pathway in humans was available until recently. Two recent studies provide support for duloxetine's mechanism of action in humans. Duloxetine was shown to have a significant effect on the excitability of pudendal motor neurons and on sphincter contractility in healthy women. In contrast, no relevant effect was observed on urethral resting tone. Another study reported important increases in Valsalva leak point pressure and in the rhabdosphincter electrical activity at rest and with coughing in women with SUI who responded to duloxetine. These studies support the hypothesis that duloxetine in women with SUI enhances urethral closure through neuromodulation of the rhabdosphincter.

[Female geriatric patients with urinary incontinence symptoms and their control over pelvic floor muscles]

Not only do anatomy and function of the pelvic floor play an important role as possible causes of female urinary incontinence, they are also crucial for its therapy. The aim of this case control study of female geriatric patients with symptoms of urinary incontinence was to determine the knowledge about their pelvic floor and to assess their ability to contract pelvic floor muscles voluntarily and reflexly.

METHODS

A total of 377 female geriatric patients with symptoms of urinary incontinence were investigated in a Basis Assessment for Urinary incontinence. The ability to contract their pelvic floor muscles was examined by a digital vaginal palpation. The extent of the registered muscle strength was graded by the Modified Oxford Grading Scale by Laycock (1994).

RESULTS

Of the patients, 65.5% were not aware of their pelvic floor and were not able to contract the pelvic floor muscles (Grade 0 to 1 by Laycock), 22% had an inaccurate knowledge and only performed an insufficient pelvic floor muscle contraction (Grade 2 by Laycock). Only 12.5% could contract their pelvic floor muscles properly (Grade 3 to 4 by Laycock). A subgroup of 83 patients had already absolved pelvic floor exercises in the past, 80 patients with conventional instructions, 3 patients with digital vaginal control. In this subgroup 54.2% of the patients were not able to contract the pelvic floor muscles (Grade 0 to 1 by Laycock) 25.3% only performed an insufficient contraction (Grade 2 by Laycock), while 20% were able to perform a sufficient and powerful contraction (Grade 3 to 4 by Laycock). The three patients in the past controlled by a digital vaginal palpation were part of this group and managed a pelvic floor muscle strength Grade 4 by Laycock. A high percentage of female geriatric patients with symptoms of urinary incontinence have a lack of understanding regarding the position and function of their pelvic floor. These results suggest that conventional pelvic floor muscle exercises without specific control are not an appropriate method to improve geriatric patients' ability to contract their pelvic floor muscles and to prevent urine leakage.

What are the supportive structures of the female urethra?

AIMS

Female stress urinary incontinence is thought to result from impairment of the connective tissue "ligaments" of the urethra. Surgical repair of female incontinence mainly involves fixation of the urethra to the pubic bone or other surrounding structures. In the present anatomical-radiological study, the anatomy of the connective tissue structures around the female urethra was investigated to determine the anatomical structures that support the urethra and the rhabdosphincter.

MATERIALS AND METHODS

The topography of the anterior compartment of the female pelvis was studied in serial sections and one anatomical preparation of 30 female fetuses and of six adult females. The pelves of 29 female fetuses were processed according to plastination histology technique. The pelves of the six adult specimens were processed according to sheet plastination technique. In addition, the anatomical findings were compared with MR images of 41 adult female volunteers.

RESULTS

The ventro-lateral aspect of the urethra remains free of fixating ligaments throughout its pelvic course. Ventro-laterally the urethra is enclosed by the ventral parts of the levator ani, its fasciae and a ventral urethral connective tissue bridge connecting both sides. Dorsally, the urethra is intimately connected to the wall of the vagina.

CONCLUSIONS

The female urethra has no direct ligamentous fixation to the pubic bone. Urethral continence after pregnancy and childbirth may be explained by a widening of the hiatus of the levator ani or the anterior vaginal wall, resulting in overstretching of the ventral urethral connective tissue bridge or the disruption of the fixation between urethra and vagina.