Stress Urinary Incontinence in Women: Review and Update on Neurological Control

A structured review on the female urethral anatomy and innervation with an emphasis on the role of the urethral longitudinal smooth muscle

A damaged sphincteric unit or support system, unstable urethral deformability or damaged sensory innervation are all potential causes of a dysfunctional urethral sphincter. With the current improvement in pharmacological targets and urodynamic understanding, studies have begun quantifying individual structures and their importance in closure pressure and consequently urethral continence. However, when it comes to the function of the longitudinal urethral smooth muscle layer, there is currently no consensus. The intent of this structured review is to critically examine literature regarding the female urethral anatomy and closure mechanism. We hypothesized that the longitudinal smooth muscle is a prerequisite for sufficient urethral closure and not merely involved during micturition. Overall opinions on a dysfunctional closure mechanism are controversial. Nonetheless, basic mechanics may be applied to understand simple urodynamics. With the assumption of longitudinal muscles forming a plug when contracted, this could have a substantial effect on the continence mechanism.

Prevalence of urinary incontinence in older Turkish women, risk factors, and effect on activities of daily living

PURPOSE

The study was conducted to determine the prevalence of urinary incontinence (UI) among older women, risk factors, and the effect on activities of daily living (ADLs).

METHOD

The study was conducted in family health centers located in a city in eastern Turkey. The study population consisted of 1094 women age 65 and older chosen with a simple random sampling method. The inclusion criteria were 65 years and older, female, and not diagnosed with mental or emotional diseases or conditions that obstruct communication. Data were collected in face-to-face interviews with the Questionnaire and Daily Life Activities Data Form created by the researchers based on the Roper, Logan, and Tierney model.

RESULTS

The prevalence of UI in women age 65 and older was 51.6%, and the most common type was urge incontinence. The number of births, number of abortions, age at last birth, and home births affected the development of UI (p<0.001). In addition, body mass index, constipation, urinary tract infection, cough, hormone replacement therapy, genital prolapse, cystocele, urogenital surgery, nocturia, and daily urine output were determined to be risk factors (p<0.001). Among the ADLs, 13.7% with UI reported that they had fallen when getting up from the toilet, 34.3% had experienced a sense of shame, 45.8% avoided coughing, and 46.5% restricted fluid intake.

CONCLUSION

Prevalence of UI in women age 65 and older was high, and the most common was urge incontinence. UI has many risk factors and affects many ADLs.

Serotonin and noradrenaline reuptake inhibitors improve micturition control in mice

Poor micturition control may cause profound distress, because proper voiding is mandatory for an active social life. Micturition results from the subtle interplay of central and peripheral components. It involves the coordination of autonomic and neuromuscular activity at the brainstem level, under the executive control of the prefrontal cortex. We tested the hypothesis that administration of molecules acting as reuptake inhibitors of serotonin, noradrenaline or both may exert a strong effect on the control of urine release, in a mouse model of overactive bladder. Mice were injected with cyclophosphamide (40 mg/kg), to increase micturition acts. Mice were then given one of four molecules: the serotonin reuptake inhibitor imipramine, its metabolite desipramine that acts on noradrenaline reuptake, the serotonin and noradrenaline reuptake inhibitor duloxetine or its active metabolite 4-hydroxy-duloxetine. Cyclophosphamide increased urine release without inducing overt toxicity or inflammation, except for increase in urothelium thickness. All the antidepressants were able to decrease the cyclophosphamide effects, as apparent from longer latency to the first micturition act, decreased number of urine spots and volume of released urine. These results suggest that serotonin and noradrenaline reuptake inhibitors exert a strong and effective modulatory effect on the control of urine release and prompt to additional studies on their central effects on brain areas involved in the social and behavioral control of micturition.

Regeneration of degenerated urinary sphincter muscles: improved stem cell-based therapies and novel imaging technologies

Stress urinary incontinence (SUI) is a largely ousted but significant medical, social, and economic problem. Surveys suggest that nowadays approximately 10% of the male and 15% of the female population suffer from urinary incontinence at some stage in their lifetime. In women, two major etiologies contribute to SUI: degeneration of the urethral sphincter muscle controlling the closing mechanism of the bladder outflow and changes in lower pelvic organ position associated with degeneration of connective tissue or with mechanical stress, including obesity and load and tissue injury during pregnancy and delivery. In males, the reduction of the sphincter muscle function is sometimes due to surgical interventions as a consequence of prostate cancer treatment, benign prostate hyperplasia, or of neuropathical origin. Accordingly, for women and men different therapies were developed. In some cases, SUI can be treated by physical exercise, electrophysiological stimulation, and pharmacological interventions. If this fails to improve the situation, surgical interventions are required. In standard procedures, endoprostheses for mechanical support of the weakened tissue or mechanical valves for a bladder outflow control are implanted. In 20% of cases treated, repeat procedures are required as implants yield all sorts of side effects in time. Based on preclinical studies, the application of an advanced therapy medicinal product (ATMP) such as implantation of autologous cells may be a curative and long-lasting therapy for SUI. Cellular therapy could also be an option for men suffering from incontinence caused by injury of the nerves controlling the muscular sphincter system. Here we briefly report on human progenitor cells, especially on mesenchymal stromal cells (MSCs), their expansion and differentiation to smooth muscle or striated muscle cells in vitro, labeling of cells for in vivo imaging, concepts of improved, precise, yet gentle application of cells in muscle tissue, and monitoring of injected cells in situ.

Cell-based therapy for the deficient urinary sphincter

When sterile culture techniques of mammalian cells first became state of the art, there was tremendous anticipation that such cells could be eventually applied for therapeutic purposes. The discovery of adult human stem or progenitor cells further motivated scientists to pursue research in cell-based therapies. Although evidence from animal studies suggests that application of cells yields measurable benefits, in urology and many other disciplines, progenitor-cell-based therapies are not yet routinely clinically available. Stress urinary incontinence (SUI) is a condition affecting a large number of patients. The etiology of SUI includes, but is not limited to, degeneration of the urinary sphincter muscle tissue and loss of innervation, as well as anatomical and biomechanical causes. Therefore, different regimens were developed to treat SUI. However, at present, a curative functional treatment is not at hand. A progenitor-cell-based therapy that can tackle the etiology of incontinence, rather than the consequences, is a promising strategy. Therefore, several research teams have intensified their efforts to develop such a therapy for incontinence. Here, we introduce candidate stem and progenitor cells suitable for SUI treatment, show how the functional homogeneity and state of maturity of differentiated cells crucial for proper tissue integration can be assessed electrophysiologically prior to their clinical application, and discuss the trophic potential of adult mesenchymal stromal (or stem) cells in regeneration of neuronal function.

Evaluation of the EmbaGYN™ Pelvic Floor Muscle Stimulator in Addition to Kegel Exercises for the Treatment of Female Stress Urinary Incontinence: A Prospective, Open-Label, Multicenter, Single-Arm Study

Aim: To assess the efficacy and safety of the EmbaGYN™ Pelvic Floor Exerciser, a battery-powered neuromuscular stimulation device with a vaginal, two-electrode stimulation probe in women with stress urinary incontinence. Materials & methods: In this prospective, open-label, multicenter, single-arm study, patients with stress urinary incontinence (n = 83) underwent 12 weeks of treatment with EmbaGYN with Kegel exercises. Results: At week 12, the mean number of incontinence episodes/day (primary end point) fell 56.2% (p = 0.152). A ≥50% decrease from baseline in incontinence episodes was seen in 65.3% of subjects (p = 0.006). The mean number of incontinence pads/day fell 57.1% (p = 0.001). Mean 24- and 1-h in-office urine loss declined 59.0% (p < 0.001) and 67% (p = 0.019), respectively. There was one nonserious device-related adverse event. Conclusion: EmbaGYN with Kegel exercises resulted in significant reductions in urine loss, incontinence pad use and improved incontinence-related quality of life, but did not have a significant effect on incontinence episodes/day.

Urinary incontinence among Turkish women: an outpatient study of prevalence, risk factors, and quality of life

PURPOSE

The aim of this study was to determine the prevalence and potential risk factors associated with urinary incontinence (UI) in women and to assess its impact on quality of life (QOL).

DESIGN

We undertook a cross-sectional study based on interviews, using a structured questionnaire.

SUBJECTS AND SETTING

Two hundred eighty-eight women, aged 19 years and older, from gynecology outpatient clinics attached to a university hospital in Ankara, Turkey, were interviewed.

INSTRUMENTS

Data were collected via a Turkish version of the international consultation on incontinence questionnaire short form (ICIQ-SF) and the Wagner's quality of life scale.

METHODS

Data were collected by face-to-face interviews with subjects and took approximately 30 minutes to complete. Potential risk factors were analyzed using logistic regression.

RESULTS

The prevalence of UI was 31.9%. Logistic regression analysis indicated that the number of pregnancies (odds ratio [OR] = 0.53, 95% CI: 0.28-0.99), UI in mother (OR = 2.46, 95% CI: 1.35-4.50) and sister (OR = 0.34, 95% CI: 0.16-0.77), previous UI during pregnancy (OR = 12.22, 95% CI: 4.11-36.36) and postpartum period (OR = 11.28, 95% CI: 3.66-34.76), and body mass index (OR = 0.49, 95% CI: 0.29-0.85) were associated with a higher likelihood of incontinence (P < .05). Ninety-two of 288 women (31.9%) stated that UI has a negative impact on their QOL and only 40 of 92 (43.5%) had asked for medical help. Impairment of QOL was related with the type of UI, frequency of UI episode, and amount of leakage.

CONCLUSION

Our study results determined that UI is common in Turkish women. The QOL of women was mostly mildly or moderately affected by UI.

Urodynamic and haemodynamic effects of a single oral administration of ephedrine or phenylpropanolamine in continent female dogs

This study investigated the effects of a single oral administration of ephedrine (2 mg/kg) or phenylpropanolamine (PPA) (1.5 mg/kg) on the vesico-urethral and cardiovascular functions in continent female dogs. Urethral pressure profilometry (UPP), arterial blood pressures and heart rate were measured in five control dogs and after single-dose treatment with ephedrine or PPA at T(0), T(2h), T(4h), T(6h), T(12h), T(18h) and T(24h). UPPs were performed under propofol anaesthesia and other measurements were performed on awake dogs. A telemetric urodynamic investigation was performed on three additional dogs for 24 h after the administration of each drug. Urethral pressures increased over 4-6 h and urethral functional lengths increased 2-6h after administration of both drugs. During micturition, a decrease in detrusor pressure coupled with an increase in bladder volume was observed after ephedrine administration and there was also an increase in bladder volume after PPA had been given. With both drugs increased arterial blood pressures at 4-6 h were compensated by a decreased heart rate over 12 h. Urethral function was improved after both ephedrine and PPA, and bladder function also improved during micturition following ephedrine.

Predictive risk factors for impaired quality of life in middle-aged women with urinary incontinence

PURPOSE

Urinary incontinence (UI) has substantial and important impacts on quality of life (QoL). The purpose of this study was to identify the associated risk factors of QoL in middle-aged women with UI.

METHODS

The participants were 127 women aged 40-64 years who experienced UI. Data were collected from October to November, 2008 using a self-reported questionnaires. The data were analyzed through t-test, one-way ANOVA, Scheffe test, and multiple linear regression with SPSS ver. 16.0 program.

RESULTS

The distribution of UI severity was mild 18.1%, moderate 40.2% and severe 41.7%. In univariate analysis, differences in the score for QoL according to participants' characteristics were statistically significant on the type of delivery, number of births and severity of UI. In multiple linear regression analysis after adjustment of other variables, the most powerful predictor of QoL is severity of UI. Number of births was also significant predictor. These two variables explained 25% of variance in QoL of women with UI.

CONCLUSIONS

UI is highly prevalent and causes suffering and impaired QoL among middle-aged women, but it stands beyond our attention. The results of this study suggest that women with moderate to severe UI should be screened for QoL by health care providers regularly. Further research is needed to determine comprehensive factors including psychosocial factors predicting the QoL for incontinent women.

Ex vivo biomechanical, functional, and immunohistochemical alterations of adrenergic responses in the female urethra in a rat model of birth trauma

Birth trauma and pelvic injury have been implicated in the etiology of stress urinary incontinence (SUI). This study aimed to assess changes in the biomechanical properties and adrenergic-evoked contractile responses of the rat urethra after simulated birth trauma induced by vaginal distension (VD). Urethras were isolated 4 days after VD and evaluated in our established ex vivo urethral testing system that utilized a laser micrometer to measure the urethral outer diameter at proximal, middle, and distal positions. Segments were precontracted with phenylephrine (PE) and then exposed to intralumenal static pressures ranging from 0 to 20 mmHg to measure urethral compliance. After active assessment, the urethra was rendered passive with EDTA and assessed. Pressure and diameter measurements were recorded via computer. Urethral thickness was measured histologically to calculate circumferential stress-strain response and functional contraction ratio (FCR), a measure of smooth muscle activity. VD proximal urethras exhibited a significantly increased response to PE compared with that in controls. Conversely, proximal VD urethras had significantly decreased circumferential stress and FCR values in the presence of PE, suggesting that VD reduced the ability of the proximal segment to maintain smooth muscle tone at higher pressures and strains. Circumferential stress values for VD middle urethral segments were significantly higher than control values. Histological analyses using antibodies against general (protein gene product 9.5) and sympathetic (tyrosine hydroxylase) nerve markers showed a significant reduction in nerve density in VD proximal and middle urethral segments. These results strongly suggest that VD damages adrenergic nerves and alters adrenergic responses of proximal and middle urethral smooth muscle. Defects in urethral storage mechanisms, involving changes in adrenergic regulation, may contribute to stress urinary incontinence induced by simulated birth trauma.

MR imaging evaluation of the pelvic floor for the assessment of vaginal prolapse and urinary incontinence

Pelvic MR imaging using the combination of motion-insensitive T2-weighted single-shot fast spin echo and high soft tissue resolution standard T2-weighted fast spin echo techniques has helped to identify soft tissue abnormalities that directly correlate with the clinical and intraoperative findings related to pelvic floor prolapse. In particular, the authors have shown that pelvic MR imaging has the ability to identify changes related to uterosacral ligament disruption and to document the corrective changes after surgical repair of this ligament. In the future, pelvic MR imaging is expected to play a progressively larger role in preoperative planning for complex or uncertain cases and for more detailed evaluation of repair in cases that do not show good symptomatic response. Pelvic MR imaging should also help to document and advance knowledge of surgical repair methodology.

Ephedrin als Alternative zu Akrinor® in der geburtshilflichen Regionalanästhesie

Hypotension in anesthesia and obstetric anesthesia in particular, is a widespread problem. After the temporary withdrawal of Akrinor from the market, the internationally available drug ephedrine is available for prevention and therapy of hypotension in anesthesia and its effect is comparable with Akrinor. In obstetric epidural anesthesia the intravenous prophylactic drug application of ephedrine seems to be superior to therapeutic application only. The aim of this overview is to show alternatives to the currently administered catecholamines for prevention of hypotension in obstetric anesthesia.