Bladder outlet obstruction index and maximal flow rate during urodynamic study as powerful predictors for the detection of urodynamic obstruction in women

Computational fluid dynamics of bladder voiding using 3D dynamic MRI

Over the last couple of decades, image-based computational fluid dynamics (CFD) has revolutionized cardiovascular research by uncovering hidden features of wall strain, impact of vortices, and its use in treatment planning, as examples, that were simply not evident in the gold-standard catheterization studies done previously. In the work presented here, we have applied magnetic resonance imaging (MRI)-based CFD to study bladder voiding and to demonstrate the feasibility and potential of this approach. We used 3D dynamic MRI to image the bladder and urethra during voiding. A surface mesh processing tool was developed to process the bladder wall prior to executing a wall-motion driven CFD simulation of the bladder and urethra. The obtained flow rate and pressure were used to calculate urodynamic nomograms, which are currently used in the clinical setting to assess bladder voiding dysfunction. These nomograms concluded that our healthy volunteer has an unobstructed bladder and normal contractility. We calculated the work done to void the bladder and propose this as an additional quantitative metric to comprehensively assess bladder function. Further, we discuss the areas that would improve this relatively new methodology of image-based CFD in urodynamics.

Validation of bladder health scales and function indices for women's research

BACKGROUND

Existing bladder-specific measures lack the ability to assess the full range of bladder health, from poor to optimal health.

OBJECTIVE

This study aimed to report evidence of validity of the self-administered, multidimensional bladder health scales and function indices for research in adult women.

STUDY DESIGN

A cross-sectional population-based validation study with random assignment to paper or electronic administration was conducted using national address-based probability sampling supplemented by purposive sampling of women with lower urinary tract symptoms in 7 clinical research centers. Construct validity of the bladder health scales and function indices was guided by a multitrait-multimethod approach using health and condition-specific questionnaires, bladder diaries, expert ratings of bladder health, and noninvasive bladder function testing. Internal dimensional validity was evaluated using factor analysis; internal reliability was assessed using paired t-tests and 2-way mixed-effects intraclass correlation coefficient models. Chi-square, Fisher exact, or t-tests were used for mode comparisons. Convergent validity was evaluated using Pearson correlations with the external construct measures, and known-group validity was established with comparison of women known and unknown to be symptomatic of urinary conditions.

RESULTS

The sample included 1072 participants. Factor analysis identified 10 scales, with Cronbach's alpha ranging from 0.74 to 0.94. Intraclass correlation coefficients of scales ranged from 0.55 to 0.94. Convergent validity of the 10 scales and 6 indices ranged from 0.52 to 0.83. Known-group validity was confirmed for all scales and indices. Item distribution was similar by mode of administration.

CONCLUSION

The paper and electronic forms of the bladder health scales and function indices are reliable and valid measures of bladder health for use in women's health research.

Diagnostic Tests for Female Bladder Outlet Obstruction: A Systematic Review from the European Association of Urology Non-neurogenic Female LUTS Guidelines Panel

CONTEXT

Female bladder outlet obstruction (fBOO) is a relatively uncommon condition compared with its male counterpart. Several criteria have been proposed to define fBOO, but the comparative diagnostic accuracy of these remains uncertain.

OBJECTIVE

To identify and compare different tests to diagnose fBOO through a systematic review process.

EVIDENCE ACQUISITION

A systematic review of the literature was performed according to the Cochrane Handbook and Preferred Reporting Items for Systematic Reviews and Meta-analyses (PRISMA) checklist. The EMBASE/MEDLINE/Cochrane databases were searched up to August 4, 2020. Studies on women ≥18 yr of age with suspected bladder outlet obstruction (BOO) involving diagnostic tests were included. Pressure-flow studies or fluoroscopy was used as the reference standard where possible. Two reviewers independently screened all articles, searched reference lists of retrieved articles, and performed data extraction. The risk of bias was assessed using Quality Assessment of Diagnostic Accuracy Studies (QUADAS-2).

EVIDENCE SYNTHESIS

Overall, 28 nonrandomised studies involving 10 248 patients were included in the qualitative analysis. There was significant heterogeneity regarding the characteristics of women included in BOO cohorts (ie, mixed cohorts including both anatomical and functional BOO). Pressure-flow studies ± fluoroscopy was evaluated in 25 studies. Transperineal Doppler ultrasound was used to evaluate bladder neck dynamics in two studies. One study tested the efficacy of transvaginal ultrasound. The urodynamic definition of fBOO also varied amongst studies with different parameters and thresholds used, which precluded a meta-analysis. Three studies derived nomograms using the maximum flow rate (Q_max) and voiding detrusor pressure at Q_max. The sensitivity, specificity, and overall accuracy ranges were 54.6-92.5%, 64.6-93.9%, and 64.1-92.2%, respectively.

CONCLUSIONS

The available evidence on diagnostic tests for fBOO is limited and heterogeneous. Pressure-flow studies ± fluoroscopy remains the current standard for diagnosing fBOO.

PATIENT SUMMARY

Evidence on tests used to diagnose female bladder outlet obstruction was reviewed. The most common test used was pressure-flow studies ± fluoroscopy, which remains the current standard for diagnosing bladder outlet obstruction in women. TAKE  HOME MESSAGE: The available evidence on diagnostic tests for female bladder outlet obstruction is limited and heterogeneous. The most common test used was video-urodynamics, which remains the current standard for diagnosing bladder outlet obstruction in women.

Obstructive patterns in videourodynamic studies predict responses of female dysfunctional voiding treated with or without urethral botulinum toxin injection: a long-term follow-up study

INTRODUCTION AND HYPOTHESIS

We report long-term changes in VUDS profiles of women with dysfunctional voiding and investigate potential predictors for treatment response.

METHODS

Women with dysfunctional voiding and available VUDS data between November 1997 and June 2018 were enrolled for retrospective analysis. The patients were all treated with medication first. In refractory patients, urethral botulinum toxin was provided as an additional option. The primary outcome was the change of VUDS parameters between baseline and follow-up studies. The secondary outcomes were baseline parameters and clinical factors that were associated with the BOOI response (> 10 points of BOOI reduction).

RESULTS

A total of 195 women with DV were included in this study. The mean age was 54.5 years old. Sixty patients received urethral botulinum toxin injection. For all patients, Pdet decreased from 47.2 to 36.8 cm H₂O (p < 0.0001), and BOOI decreased from 26.4 to 17.7 (p = 0.0001). Patients with urethral injection had significantly smaller Qmax, voided volume, and voiding efficiency (VE) and significantly larger PVR and BOOI at baseline, indicating a severer obstruction in this group. The overall BOOI response rate was 44% (85/195). A higher baseline BOOI was associated with the BOOI response in multivariate analysis.

CONCLUSIONS

In this long-term study of women with dysfunctional voiding, medical treatment with or without urethral botulinum toxin injection both resulted in reduction of Pdet and BOOI. A more prominent obstructive profile at baseline VUDS study was associated with a higher rate of BOOI response at follow-up study.

Predictors for De Novo Overactive Bladder after Readjustable Mid-Urethral Sling Procedure in Women with Stress Urinary Incontinence due to Intrinsic Sphincter Deficiency

Purpose

This study identified noninvasive factors that predict overactive bladder (OAB) after readjustable mid-urethral sling surgery (Remeex system) in women with stress urinary incontinence (SUI) due to intrinsic sphincter deficiency (ISD).

Materials and Methods

We retrospectively reviewed the medical records of 130 women with SUI due to ISD [Valsalva leak-point pressure (VLPP) <60 cm H₂O] who underwent the Remeex procedure between February 2011 and March 2017. Patients were classified according to OAB symptoms before and 6 months after the Remeex procedure: Group 1, without preoperative and postoperative OAB (n=46); Group 2, without preoperative OAB and with postoperative OAB (de novo OAB, n=15); Group 3, with preoperative OAB and without postoperative OAB (n=25); Group 4, with preoperative and postoperative OAB (n=44). Noninvasive clinical and urodynamic factors were evaluated as predictors of de novo OAB.

Results

The four groups significantly differed with respect to age (p=0.036), peak urinary flow rate (PUFR) one month after surgery (post-PUFR, p=0.001), and postvoid residual (PVR) one month after surgery (post-PVR, p=0.005). No significant differences were detected for body mass index, diabetes, multiparity, menopause, previous hysterectomy, previous incontinence surgery, previous pelvic organ prolapse surgery, pyuria, preoperative PUFR, preoperative PVR, maximal cystometric capacity, VLPP, maximum urethral closure pressure, detrusor pressure at PUFR, and detrusor overactivity (p>0.05). Post-PUFR decreased significantly compared with preoperative PUFR in Groups 1, 2, and 4 (p=0.002, p=0.001, and p=0.001, respectively). Pairwise comparisons of post-PUFR and post-PVR revealed statistically significant differences between Group 2 and other groups (p<0.0125). Multivariate logistic regression analyses showed that post-PUFR was the only significant predictor of de novo OAB (odds ratio = 0.823, 95% confidence interval 0.727-0.931, p=0.002).

Conclusions

Reduced PUFR after the Remeex procedure is a promising predictor of risk for de novo OAB. This metric is noninvasive and easy to measure.

Videourodynamic Studies of Women with Voiding Dysfunction

This retrospective study is aimed to present videourodynamic findings of women with symptoms of voiding dysfunction in a medical center. Of 1914 women, the diagnoses included bladder outlet obstruction (BOO, n = 810, 42.3%), bladder dysfunction (n = 1,048, 54.8%) and normal tracings (n = 56, 2.9%). Anatomic BOO (n = 49) included cystocele (n = 19) and urethral stricture (n = 30). Common functional BOOs included dysfunctional voiding (n = 325, 17.0%) and poor relaxation of the external sphincter (n = 336, 17.6%). Common bladder dysfunction subtypes included detrusor underactivity (n = 337, 17.6%), detrusor hyperactivity with impaired contractility (n = 231, 12.1%), and bladder oversensitivity (n = 325, 17.0%). Receiver operating characteristic (ROC) analysis were performed, and the following optimum cutoff values were determined: (1) voiding detrusor pressure at a maximum flow rate (Pdet.Qmax) = 30 cmH₂O for differentiating BOO from bladder dysfunction and normal tracings, with an ROC area of 0.78; (2) the Abrams-Griffiths number = 30 for differentiating anatomic from functional BOO, with an ROC area of 0.66; (3) post-void residual = 200 mL for differentiating bladder neck dysfunction from the other BOOs, with an ROC area of 0.69; (4) Pdet.Qmax = 30 cmH₂O for differentiating dysfunctional voiding from poor relaxation of the external sphincter with an ROC area of 0.93. The above findings can be used as initial guide for management of female BOO.

Use of free uroflowmetry vs pressure-flow studies in the diagnosis of overactive bladder syndrome in females

OBJECTIVES

To determine if pressure-flow study (PFS) parameters, including flow index (FI) calculated by dividing average urethral flow by maximal urethral flow, increase the accuracy of urodynamic studies in the diagnosis of overactive bladder (OAB).

STUDY DESIGN

Retrospective study to evaluate the medical history and urodynamic examination results of female patients diagnosed with lower urinary tract symptoms (LUTS) between January 2014 and December 2015. Patients were stratified into four groups depending on the type of LUTS: OAB; stress urinary incontinence (SUI); mixed urinary incontinence with predominant SUI symptoms (MUI-SUI); and mixed urinary incontinence with predominant OAB symptoms (MUI-OAB).

RESULTS

OAB was diagnosed in 26 (15%) patients, SUI was diagnosed in 93 (52%) patients, MUI-OAB was diagnosed in 43 (24%) patients, and MUI-SUI was diagnosed in 17 (9%) patients. FI calculated using free uroflowmetry (FI-free) was significantly lower in the OAB group compared with the other groups (p<0.01). Analysis revealed no difference in FI-free between the SUI, MUI-SUI and MUI-OAB groups. Significant differences were found between the study groups for most free uroflowmetric parameters, including maximal urethral flow, average urethral flow and micturition volume (p<0.05). Similar differences were not found in PFS parameters.

CONCLUSIONS

The decrease in the urethral lumen due to the presence of a transurethral catheter in patients with OAB, in contrast to women with SUI and MUI, was not found to influence FI calculated using free uroflowmetry or PFS. FI may serve as an important objective diagnostic tool for OAB, but only when calculated from free uroflowmetry parameters when assessing patients with LUTS.

Pressure-flow nomogram for women with lower urinary tract symptoms

INTRODUCTION

Results of urodynamic studies performed in female patients are often difficult to interpret. The objective of the study was to develop a nomogram that would help in diagnosing functional bladder outlet obstruction (BOO) in neurologically intact women with any kind of lower urinary tract symptoms.

MATERIAL AND METHODS

From the urodynamic database adult women were chosen with maximal flow rate (Q max ) ≤ 12 ml/s in a pressure-flow study. Four criteria were used to identify a group of patients suspected of BOO: thickened bladder wall, presence of bladder diverticula, subjective improvement on α-blockers and improvement of voiding symptoms on any form of treatment. The line separating high and low pressure zones on the pressure-flow chart was established according to the position of patients who met at least one of them.

RESULTS

Sixty-seven patientswere investigated. Twenty-one women met at least one of the specified criteria. They had significantly higher voiding pressures (p det(Qmax) 35 cm H2O vs. 16.5 cm H2O; p = 0.002). A new nomogram with one separating line (p det(Qmax) = 1.5 × Q max + 10) was proposed. The difference in the distribution of women fulfilling the criteria between high pressure zone and low pressure zone was highly significant (19/35 vs. 2/32; p < 0.0001). Sensitivity, specificity, positive and negative predictive values of our nomogram in identifying patients suspected of BOO was 90.5%, 65.2%, 54.3% and 94% respectively.

CONCLUSIONS

The new nomogram can be considered a screening test which efficiently excludes obstruction among women with low Q max in a pressure-flow study.

Changes in urodynamic measures two years after Burch colposuspension or autologous sling surgery

OBJECTIVE

To characterize the urodynamic (UDS) changes in subjects 24 months after Burch urethropexy and autologous fascial sling surgery for stress urinary incontinence.

METHODS

In the Stress Incontinence Surgical Treatment Efficacy Trial (SISTEr), 655 women underwent standardized UDSs before and 2 years after Burch or sling surgery. Paired t tests were used to compare the pre- and postoperative UDS measures by treatment group. Analysis of variance models were fit predicting the change in UDS measures, controlling for the treatment group.

RESULTS

The noninstrumented maximal flow rate decreased 3.6 mL/s in the Burch group and 4.7 mL/s in the sling group (P = .42). The average flow rates also decreased (2.4 mL/s in the Burch group and 3.8 mL/s in the sling group, P = .039). No difference was found in the increases in first sensation between the Burch and sling groups (23.3 and 29.3 mL, respectively, P = .61). Also, no differences were found in the reduction in the pressure flow study maximal flow rates (2.3 mL/s in the Burch group and 4.4 mL/s in the sling group, P = .11). An increased detrusor pressure at maximal flow rate (11.4 cm H(2)O, P < .001) was seen only after the sling procedure. Increases in the bladder outlet obstruction index occurred after both procedures, with greater increases seen after sling surgery (change, Burch +6.27 vs sling +20.12, P = .001).

CONCLUSION

The Burch colposuspension and autologous fascial sling procedures were associated with similar decreases in noninstrumented flow rates, and the sling was associated with greater increases in the detrusor pressure at maximal flow rate and bladder outlet obstruction index. These changes suggest that both procedures are effective, in part, because of increased outlet resistance. However, the sling procedure might be more obstructive.

Urodynamic changes associated with successful stress urinary incontinence surgery: is a little tension a good thing?

OBJECTIVE

To identify urodynamic changes that correlate with successful outcomes after stress urinary incontinence (SUI) surgery.

METHODS

Six-hundred fifty-five women were randomized to Burch colposuspension or autologous fascial sling as part of the multicenter Stress Incontinence Surgical Treatment Efficacy Trial. Preoperatively and 24 months after surgery, participants underwent standardized urodynamic testing that included noninvasive uroflowmetry, cystometrogram, and pressure flow studies. Changes in urodynamic parameters were correlated to a successful outcome, defined a priori as (1) negative pad test; (2) no urinary incontinence on 3-day diary; (3) negative cough and Valsalva stress test; (4) no self-reported SUI symptoms on the Medical, Epidemiologic and Social Aspects of Aging Questionnaire; and (5) no re-treatment for SUI.

RESULTS

Subjects who met criteria for surgical success showed a greater relative increase in mean Pdet@Qmax (baseline vs 24 months) than women who were considered surgical failures (P = .008). Although a trend suggested an association between greater increases in bladder outlet obstruction index and outcome success, this was not statistically significant. Other urodynamic variables, such as maximum uroflow, bladder compliance, and the presence of preoperative or de novo detrusor overactivity did not differ with respect to outcome status.

CONCLUSIONS

Successful outcomes in both surgical groups (Burch and sling) were associated with higher voiding pressures relative to preoperative baseline values. However, concomitant changes in other urodynamic voiding parameters were not significantly associated with outcome.

Subjective and objective measures of late genitourinary morbidity following hypofractionated radiotherapy in men with prostate cancer

To value the late genitourinary (GU) morbidity in men treated with a hypofractionated radiotherapy regimen for prostate cancer. Patients with intermediate risk factors according to D'Amico's criteria were selected. The hypofractionated schedule consisted of 15 fractions of 3.63 Gy delivered three times per week for a total dose of 54.3 Gy. Significant changes in storage-symptoms were not found. A significant transient worsening in the score of late effects of normal tissue late effects normal tissue task force (LENT)-subjective, objective, management, analytic (SOMA) urinary-function domain was observed at 12 months with subsequent improvement at 28 months. The assessment of voiding-symptoms and maximum urinary flow rate (Qmax) showed that no significant difference was measurable at 12 and 28 months. For PVR, a transient increase at 12 months with a subsequent decrease at 28 months was measured. No significant increase in alpha-blockers usage and in the percentage of men with pathological nonintubated uroflowmetry (NIF) was observed at 12 and 28 months. Finally, patients did not perceive any clinical worsening in their quality of life (QoL) as attested by the International Prostate Symptom Score (IPSS)-QoL. Our study seems to suggest that our hypofractionated radiotherapy schedule for the treatment of prostate cancer is safe in terms of late urinary morbidity. Further study will be required to confirm our results.

Measurement of the thickness of the urethrovaginal space in women with or without vaginal orgasm

INTRODUCTION

The physiology and anatomy of female sexual function are poorly understood. The differences in sexual function among women may be partly attributed to anatomical factors.

AIM

The purpose of this study was to use ultrasonography to evaluate the anatomical variability of the urethrovaginal space in women with and without vaginal orgasm.

METHODS

Twenty healthy, neurologically intact volunteers were recruited from a population of women who were a part of a previous published study. All women underwent a complete urodynamic evaluation and those with clinical and urodynamic urinary incontinence, idiopathic detrusor overactivity, or micturition disorders, as well as postmenopausal women and those with sexual dysfunction were excluded. The reported experience of vaginal orgasm was investigated.

MAIN OUTCOME MEASURE

The urethrovaginal space thickness as measured by ultrasound was chosen as the indicator of urogenital anatomical variability. Designated evaluators carried out the measurements in a blinded fashion.

RESULTS

The urethrovaginal space and distal, middle, and proximal urethrovaginal segments were thinner in women without vaginal orgasm. A direct correlation between the presence of vaginal orgasm and the thickness of urethrovaginal space was found. Women with a thicker urethrovaginal space were more likely to experience vaginal orgasm (r = 0.884; P = 0.015). A direct and significant correlation between the thickness of each urethrovaginal segment and the presence of vaginal orgasm was found, with the best correlation observed for the distal segment (r = 0.863; P < 0.0001). Interobserver agreement between the designated evaluators was excellent (r = 0.87; P < 0.001).

CONCLUSIONS

The measurement of the space within the anterior vaginal wall by ultrasonography is a simple tool to explore anatomical variability of the human clitoris-urethrovaginal complex, also known as the G-spot, which can be correlated to the ability to experience the vaginally activated orgasm.

Primary bladder neck obstruction in men, women, and children

The understanding of the presentation, diagnosis, and treatment of primary bladder neck obstruction (PBNO) has evolved over the last 20 years. It was first identified 70 years ago, but the etiology is still unclear. There are multiple theories as to the etiology, including muscular and neurological dysfunction and fibrosis. Over the years, many voiding parameters and cut points and nomograms have been presented for diagnosis of nonneurogenic functional bladder outlet obstruction in young men. Until recently, there was a paucity of data on PBNO in women and children. Videourodynamics provide an accurate diagnosis of PBNO but for some patients are an invasive option. Treatments vary from watchful waiting to alpha-blockade to surgery, depending on the severity of symptoms, urodynamic findings, and response to medical therapy. This paper reviews the theories on etiology, incidence, presentation, and diagnostic evaluation, and briefly discusses treatment options for PBNO.