Ultrasound of the female urethra

Background: Many theories have been put forward to explain the urinary continence mechanism. Though they seem logical, there is insufficient evidence to support them. Ultrasound has been implemented by researchers to investigate these theories. There is considerable difference in their methodologies and their conclusions. Most of the research on urethral ultrasound is related to stress incontinence; there is a lack of studies on other urodynamic diagnoses. Aim: To compare the measurements of the female urethra by transperineal ultrasound in women with different urodynamic diagnoses and different vaginal parities. Methodology: 150 women had urodynamic studies and 2 and 3 dimensional transperineal ultrasound. They were divided into 4 groups according to their urodynamic diagnosis as nondiagnostic urodynamics(NU), pure detrusor overactivity(PureDO), pure urodynamic stress incontinence(PureUSI) and mixed urinary incontinence(MUI) and also according to their vaginal parity. New methods of measuring urethral position, bladder neck position and urethral dimension are developed and used for measurement. Multiple regression analysis was performed using a model of urethral sphincter volume(USV), bladder neck position(BNP) and pubourethral distance. Key findings: USV was smallest in PureUSI and largest in PureDO groups. BNP at rest was lower in all incontinent groups than NU. MUI group had normal sphincter size but lower BNP. There was no difference in the bladder neck mobility or urethral mobility. Urethral compression was evident in all groups. The statistical model correctly classified 68.2% women with urodynamic stress incontinence and 69.8% women with detrusor overactivity. The urethral sphincter was smaller in women who had a vaginal delivery but there was no difference in the sphincter size of primiparous and multiparous women. Conclusion: Urethral sphincter volume and bladder neck position are the most differentiating factors for the types of urinary incontinence. Subsequent vaginal delivery in primiparous women may not increase their risk of having urinary incontinence.Open Acces

VOIDING DYSFUNCTION AND DETRUSOR INSTABILITY AFTER THE COLPOSUSPENSION OPERATION FOR GENUINE STRESS INCONTINENCE

Colposuspension is an effective treatment for genuine stress incontinence. Continence is restored by positioning the bladder neck in a fixed and elevated retro-pubic position. Despite a high success rate of up to 90%, post-operative complications occur which may have an adverse effect on quality of life. Voiding difficulties develop in 0-43% of patients and detrusor instability in 2- 25%. This considerable variability is due to differences in definition, the timing of assessment, patient selection, and probably also in surgical technique. The natural history of these complications is not clearly known due to the lack of prospective follow-up studies. There is also general uncertainty with regards to their causes. While retrospective studies have attempted to identify pre-operative risk factors, there are no prospective studies which attempt to correlate the anatomical and functional changes caused by surgery with the development of voiding dysfunction and detrusor instability. This study has investigated prospectively 77 women undergoing the operation of colposuspension in relation to the incidence, natural history and causes of post-operative voiding dysfunction and detrusor instability. The complications were identified and followed-up objectively by means of serial urodynamic studies. Patients were also assessed clinically and using quality of life measures. The development of complications were correlated to a number of anatomical and functional changes caused by surgery. Anatomical changes were identified mainly by imaging the bladder neck with Magnetic Resonance Imaging (MRI). Functional changes were identified using urodynamic studies. Voiding dysfunction after colposuspension was common, with 69% of women requiring a catheter for more than seven days, and 28% for longer than 14 days. Improvement occurred gradually in most cases, with only 7. 7% and 2.5% of them needing catheterization at three months and one year respectively. De novo detrusor instability occurred in 21% of women at three months follow-up, and was symptomatic in 66% of these cases. Objective and subjective resolution was seen in 50% of these at one year follow-up. Quality of life after colposuspension improved in most cases despite the development of these complications, probably due to the resolution of their incontinence. Voiding dysfunction and detrusor instability after colposuspension were found to be multifactorial, due to patient related factors (age and detrusor contractility for voiding dysfunction, and age and a past history of bladder neck surgery for detrusor instability), and to operative factors (amount of bladder neck elevation and urethral compression). These findings might lead to the development of preventative measures

Factors Associated with Subjective Improvement Following Midurethral Sling Procedures for Stress Urinary Incontinence: A Masters Thesis

Background Female stress urinary incontinence (SUI) greatly affects quality of life. The midurethal sling (MUS) procedure has been widely accepted as the standard of care treatment for SUI, although there is little information regarding patients\u27 subjective reports of symptom improvement. Objectives The objective of this study was to identify clinical and demographic characteristics that predict subjective symptom improvement following MUS procedures in women with SUI. Materials and Methods The study design was retrospective cohort. Subjects included women who underwent MUS between 2006 and 2008, returned mailed surveys and met our predefined inclusion criteria. Pre-operative data included demographics, prior surgery, co-morbid diseases, urodynamics and concomitant reconstructive surgery. Subjective improvement was measured by score improvement on the UIQ-7, UDI-6, the UDI stress subscale and Question 3 of the UDI, Do you experience urine leakage related to physical activity, coughing, or sneezing? Results The mean age of the study sample was 57 years, parity was 2.5 and BMI was 28. Subjects with lower MUCP demonstrated more improvement on the UIQ-7. ΔUDI-6 stress subscale scores were more sensitive to symptom change than either the ΔUDI-6 or ΔUIQ-7. Older, menopausal subjects with urethral hypermobility and concomitant vaginal suspension showed less improvement than subjects without these characteristics. After controlling for urethral straining angle, PVR, menopause and time out from surgery, older age and concomitant vaginal suspension were associated with persistent post-op symptoms on the UDI-6 Question 3 and age remained the only variable associated with persistent symptoms on the UDI-6 stress subscale. Conclusion Concurrent vaginal suspension and advancing age were risk factors for persistent symptoms following MUS procedures in patients with SUI. Symptoms may recur after 24 post-operative months. Clinicians are encouraged to provide additional preoperative counseling to those women who are at greatest risk for persistent symptoms

Accuracy of bladder ultrasound in the diagnosis of detrusor overactivity (BUS study)

Objective To estimate the accuracy of bladder wall thickness (BWT), measurement by transvaginal bladder ultrasound (BUS) in diagnosing detrusor overactivity (DO) Methods A multicenter study in 687 women with overactive bladder or urgency predominant mixed incontinence in 22 centres was undertaken. Index test was BWT and urodynamics was the reference standard. Reproducibility of BWT and the acceptability of BWT and urodynamics were also studied. Results BWT showed poor sensitivity, specificity and likelihood ratios at all pre-specified cut-offs. The ROC curve showed no evidence of discrimination at any threshold between those with and without DO (p=0.25): the AUC was 0.53, 95%CI: (0.48, 0.57). In the prospective interobserver variation study of scans performed by two independent observers, the SD 0.95mm with an analytical variability of 0.76mm.There was a trend towards greater acceptability of BWT scan compared to urodynamics (p<0.001), (81% versus 56%). Conclusion Bladder wall thickness measurement did not discriminate women with DO versus those without DO and hence is not an accurate test for diagnosing DO. Transvaginal BWT does not have sufficient reliability and reproducibility. Women experienced higher levels of embarrassment and a lower rate of acceptability with urodynamics compared to the BWT scan procedure

Human detrusor smooth muscle metabolism and the pathophysiology of detrusor instability in women

The pathophysiology of abnormal detrusor function and the development of unstable detrusor contractions is a significant clinical problem, particularly in women. The treatment available is often ineffective and is associated with many uncomfortable side effects. Often the unstable contractions occur together with damaged bladder neck support following pelvic floor damage sustained in childbirth. In women these unstable contractions are not usually associated with bladder outlet obstruction such as occurs in men with prostatic hypertrophy. Most of the human and animal research has concentrated on abnormal bladder function as a consequence of bladder outlet obstruction and this study sought to investigate possible mechanisms of the development of abnormal bladder function in the absence of such obstruction. Abnormal detrusor smooth muscle metabolism as a result of bladder ischaemia has been proposed as a pathophysiological process contributing to the development of abnormal bladder function and unstable bladder contractions. In this work the role of cellular hypoxia, specifically, in this pathophysiological process was studied in vitro using biopsies from human stable and unstable bladders, either as isolated multicellular preparations or isolated single myocytes. Cellular hypoxia was found to reduce the force of a carbachol induced contraction in isolated detrusor muscle strips, the biopsies from control bladders being more affected than those from unstable bladders. Isolated single cell experiments demonstrated that cellular hypoxia attenuated the intracellular Ca+2-transient released from the sarcoplasmic reticulum in response to muscarinic stimulation, however cellular hypoxia had no effect on the surface membrane electrophysiological properties

Muro-Neuro-Urodynamics:a review of the functional assessment of mouse lower urinary tract function

Background: Mouse urodynamic tests are fundamental to understanding normal lower urinary tract (LUT) function. These experiments also contribute to our understanding of neurological dysfunction, pathophysiological processes, and potential mechanisms of therapy. Objectives: Systematic assessment of published evidence on urodynamics, advantages and limitations of different urodynamic measurements in mice, and consideration of potential implications for the clinical field. Methods: A search using specific search-terms for urodynamic studies and mice was conducted on PubMed (from inception to 1 July 2016). Results: We identified 55 studies examining or describing mouse neuro-urodynamics. We summarize reported features of mouse urodynamic function deriving from frequency-volume chart (FVC) measurements, voiding spot assays, filling cystometry, and pressure-flow studies. Similarly, an influence of the diurnal cycle on voiding is observed in mice and should be considered when interpreting rodent urodynamic studies, especially FVC measurements and voiding spot assays. Anaesthesia, restraint conditions, or filling rate influence mouse neuro-urodynamics. Mouse cystometric studies have observed intravesical pressure oscillations that accompany urine flow, attributed to high frequency opening and closing of the urethra. This characterization is not seen in other species, except rats. In contrast to human clinical urodynamics, the terminology of these examinations has not been standardized although many rodent urodynamic studies have been described. Conclusion: Mice have many anatomical and physiological similarities to humans and they are generally cost effective, and allow investigation of the effects of aging because of their short lifespan. There are some differences between mouse and human urodynamics. These must be considered when interpreting LUT function in mice, and translational value of murine disease models

Animal Models of Double Incontinence: “Fecal and Urinary”

Throughout the world, animal models are being used as simulators of human anatomy and pathophysiology with most of the investigations and treatments first tested on them. Double incontinence (DI) includes both urinary and anal incontinence. This chapter is focused on the use of animals as models to understand pathogenesis, diagnosis and management of double incontinence (DI). DI is a complex disease with variant prevalence around the world which has a severe impact on quality of life (Qol). Many studies are designed to employ rodent and rabbit models to understand the pathogenesis of urinary and fecal incontinence. Urodynamic studies including leak point pressure (LPP) and urethral pressure profilometry (UPP) are used in establishing diagnosis of stress urinary incontinence. Rats have also been used to study fecal incontinence using neurophysiological and sacral nerve stimulation tests. The surgical treatment of double incontinence involves use of mesh, which was initially tested on animals. Animal models have also been used to train surgeons for perineal tear repair surgery. We conclude that the use of animal models provides best approach to learn these specialized surgical skills for medical practitioners and researchers