Sonographic transvaginal bladder wall thickness: does the measurement discriminate between urodynamic diagnoses?

Recent developments in diagnostic ultrasound for lower urinary tract function

Ultrasonography (US) is an essential tool in the clinical management of lower urinary tract dysfunction (LUTD), including lower urinary tract symptoms, overactive bladder, and benign prostatic hyperplasia, in which prostatic volume and post-void residual volume are routinely used to evaluate the pathophysiological characteristics of afflicted patients. US can also be employed to diagnose hydronephrosis and bladder calculus as complications of severe LUTD. Moreover, US is essential for identifying pathophysiological characteristics and surgical indications, predicting disease development and drug efficacy, and monitoring bladder function improvement by means of such parameters as bladder wall thickness, prostatic urethral length, intravesical prostatic protrusion, and prostatic urethral angulation/angle. Herein, I narratively review the recent advances in US approaches for the management of LUTD, especially in adult males.

ACR Appropriateness Criteria® Pelvic Floor Dysfunction in Females

Pelvic floor disorders including pelvic organ prolapse (POP), urinary dysfunction, defecatory dysfunction, and complications after pelvic floor surgery are relatively common in the female population. Imaging tests are obtained when the initial clinical evaluation is thought to be incomplete or inconclusive or demonstrates findings that are discordant with patients' symptoms. An integrated imaging approach is optimal to evaluate the complex anatomy and dynamic functionality of the pelvic floor. Fluoroscopic cystocolpoproctography (CCP) and MR defecography are considered the initial imaging tests of choice for evaluation of POP. Fluoroscopic voiding cystourethrography is considered the initial imaging test for patients with urinary dysfunction. Fluoroscopic CCP and MR defecography are considered the initial imaging test for patients with defecatory dysfunction, whereas ultrasound pelvis transrectal is a complementary test in patients requiring evaluation for anal sphincter defects. MRI pelvis without and with intravenous contrast, MRI pelvis with dynamic maneuvers, and MR defecography are considered the initial imaging tests in patients with suspected complications of prior pelvic floor surgical repair. Transperineal ultrasound is emerging as an important imaging tool, in particular for screening of pelvic floor dysfunction and for evaluation of midurethral slings, vaginal mesh, and complications related to prior pelvic floor surgical repair. The American College of Radiology Appropriateness Criteria are evidence-based guidelines for specific clinical conditions that are reviewed annually by a multidisciplinary expert panel. The guideline development and revision include an extensive analysis of current medical literature from peer reviewed journals and the application of well-established methodologies (RAND/UCLA Appropriateness Method and Grading of Recommendations Assessment, Development, and Evaluation or GRADE) to rate the appropriateness of imaging and treatment procedures for specific clinical scenarios. In those instances where evidence is lacking or equivocal, expert opinion may supplement the available evidence to recommend imaging or treatment.

Presurgical bladder wall thickness is a useful marker to predict the postsurgical improvement of symptoms in patients with pelvic organ prolapse-related overactive bladder

Objectives

Pelvic organ prolapse (POP) is a cause of overactive bladder (OAB), and transvaginal mesh (TVM) surgery can improve the symptoms. Bladder wall thickness (BWT) is a useful and safe marker to evaluate bladder function in urinary disorders. The main purpose of this study is to clarify the relationship between BWT and changes in the OAB symptom score (OABSS) after TVM operation in patients with POP.

Methods

BWT was measured by ultrasonography before and 6 months after surgery at three sites in the bladder: the anterior wall, trigone, and dome. Similarly, the OABSS was evaluated at the time of BWT measurement. Changes induced in BWT at each site and the mean BWT at all sites after TVM surgery were analyzed. Similarly, the relationship between presurgical BWT and the decrease in OABSS was investigated.

Results

TVM surgery improved OABSS in 30 patients (responders; 73.2%), while 11 patients were judged as nonresponders (26.8%). BWT at the anterior bladder wall and dome as well as the mean BWT at all three sites were significantly decreased by TVM surgery (P < .001). Similar trends were identified in OABSS responders; however, all markers showed no significant changes in OABSS nonresponders. All the BWT‐related markers before surgery were significantly lower in OABSS responders than in OABSS nonresponders.

Conclusions

BWT at the bladder anterior wall and dome, but not the trigone, were decreased by TVM surgery. We conclude that presurgical BWT may be a useful marker to predict the improvement in OAB symptoms by TVM surgery in patients with POP‐related OAB.

Sonographic evaluation of bladder wall thickness in women with lower urinary tract dysfunction

Objective

To investigate the correlation between bladder wall thickness (BWT) measured by ultrasonography and lower urinary tract dysfunction (LUTD) in patients with lower urinary tract symptoms (LUTS).

Methods

Forty-eight women with LUTS who underwent urodynamic study and BWT by ultrasonography as outpatients were studied. We assessed LUTS during a medical examination by interview. The thinnest part of the bladder wall was measured by a transabdominal ultrasonography. We excluded patients who had visited another hospital previously because we did not know what treatment they had received, including medications, behavioral therapy, or other treatments. We constructed receiver operating characteristic (ROC) curves for diagnosis of LUTD and also determined reliable BWT criteria by calculating the area under the curve. Statistical analyses were performed using the Kolmogorov-Smirnov method and Student's t-test.

Results

The mean age, body mass index, and duration of symptoms were 59.9±9.7 years, 26.06±3.4 kg/m², and 53.4±38.2 months, respectively. Urodynamic study parameters (Valsalva leak point pressure, maximal urethral closure pressure, functional length, and postvoid residual volume) were lower in patients with BWT <3 mm; however, these differences were not significant. Patients with BWT ≥3 mm developed a hypoactive bladder (P=0.009) and intrinsic sphincter deficiency (ISD) (P=0.001) at a significantly higher rate. According to the ROC analysis, the best BWT cut-off value was 3 mm for overactive bladder diagnosis.

Conclusions

Women with LUTD showed higher BWT values (≥3 mm), especially patients with hypoactive bladder and ISD. Sonographic evaluation of BWT is an easy, fast, and noninvasive method for possible diagnostic tool for LUTD.

Bladder ultrasonography for diagnosing detrusor overactivity: test accuracy study and economic evaluation

BACKGROUND

Urodynamics (UDS) has been considered the gold standard test for detrusor overactivity (DO) in women with an overactive bladder (OAB). Bladder ultrasonography to measure bladder wall thickness (BWT) is less invasive and has been proposed as an alternative test.

OBJECTIVES

To estimate the reliability, reproducibility, accuracy and acceptability of BWT in women with OAB, measured by ultrasonography, in the diagnosis of DO; to explore the role of UDS and its impact on treatment outcomes; and to conduct an economic evaluation of alternative care pathways.

DESIGN

A cross-sectional test accuracy study.

SETTING

22 UK hospitals.

PARTICIPANTS

687 women with OAB.

METHODS

BWT was measured using transvaginal ultrasonography, and DO was assessed using UDS, which was performed blind to ultrasonographic findings. Intraobserver and interobserver reproducibility were assessed by repeated measurements from scans in 37 and 57 women, respectively, and by repeated scans in 27 women. Sensitivity and specificity were computed at pre-specified thresholds. The smallest real differences detectable of BWT were estimated using one-way analysis of variance. The pain and acceptability of both tests were evaluated by a questionnaire. Patient symptoms were measured before testing and after 6 and 12 months using the International Consultation on Incontinence modular Questionnaire Overactive Bladder (short form) (ICIQ-OAB) questionnaire and a global impression of improvement elicited at 12 months. Interventions and patient outcomes were analysed according to urodynamic diagnoses and BWT measurements. A decision-analytic model compared the cost-effectiveness of care strategies using UDS, ultrasonography or clinical history, estimating the cost per woman successfully treated and the cost per quality-adjusted life-year (QALY).

RESULTS

BWT showed very low sensitivity and specificity at all pre-specified cut-off points, and there was no evidence of discrimination at any threshold (p = 0.25). Extensive sensitivity and subgroup analyses did not alter the interpretation of these findings. The smallest detectable difference in BWT was estimated to be 2 mm. Pain levels following both tests appeared relatively low. The proportion of women who found the test 'totally acceptable' was significantly higher with ultrasonography than UDS (81% vs. 56%; p < 0.001). Overall, subsequent treatment was highly associated with urodynamic diagnosis (p < 0.0001). There was no evidence that BWT had any relationship with the global impression of improvement responses at 20 months (p = 0.4). Bladder ultrasonography was more costly and less effective than the other strategies. The incremental cost-effectiveness ratio (ICER) of basing treatment on the primary clinical presentation compared with UDS was £491,500 per woman successfully treated and £60,200 per QALY. Performing a UDS in those women with a clinical history of mixed urinary incontinence had an ICER of £19,500 per woman successfully treated and £12,700 per QALY compared with the provision of urodynamic to all women. For DO cases detected, UDS was the most cost-effective strategy.

CONCLUSION

There was no evidence that BWT had any relationship with DO, regardless of the cut-off point, nor any relationship to symptoms as measured by the ICIQ-OAB. Bladder ultrasonography has no diagnostic or prognostic value as a test in this condition. Furthermore, despite its greater acceptability, BWT measurement was not sufficiently reliable or reproducible.

TRIAL REGISTRATION

Current Controlled Trials ISRCTN46820623.

FUNDING

This project was funded by the National Institute for Health Research (NIHR) Health Technology Assessment programme and will be published in full in Health Technology Assessment; Vol. 20, No. 7. See the NIHR Journals Library website for further project information.

Assessment of bladder wall thickness in women with overactive bladder

OBJECTIVE

To compare bladder wall thickness (BWT) between female patients with overactive bladder (OAB) and aged-matched healthy controls.

MATERIAL AND METHODS

Thirty-six female patients with OAB and 31 healthy women were enrolled in the present prospective observational study. Qmax and Qave were measured by using uroflowmetry in all of the women in the patient and control groups, and also maximum bladder capacity (MBC), post- void residual urine (PVRU), prevoiding and postvoiding BWT were measured by using transabdominal ultrasound. Lower urinary tract symptoms of the participants were assessed by using Overactive Bladder Version-8 (OAB-V8) and International Consultation on Incontinence Questionnaire-Short Form (ICIQ-SF). All of the data were statistically compared between the patient and control groups. In the patient group, the relationships between parameters were evaluated correlation analysis.

RESULTS

The mean age of the patients and controls were similar (respectively, 45.58±12.35 and 44.21±11.60 years (p=0.68). The mean pre- and post-voiding BWT, OAB-V8 and ICIQ-SF scores of the patients were significantly higher than the controls. In the patient group, the moderate positive correlations between BWT with Qmax (p=0.02) and Qave (p=0.02) were found.

CONCLUSION

This study showed that the BWTs of the female patients with OAB are higher than those of healthy women. Further studies should investigate the changes in BWT of patients with OAB after treatment of OAB.

Novel minimally invasive laser treatment of urinary incontinence in women

BACKGROUND AND OBJECTIVE

Urinary incontinence (UI) is a common disorder that affects women of various ages and impacts all aspects of life. Our aim was to evaluate the non-invasive erbium:yttrium-aluminum-garnet (Er:YAG) laser that exploits its thermal effect and has been used in reconstructive and rejuvenation surgery as a potential treatment strategy for stress UI (SUI) and mixed UI (MUI).

STUDY DESIGN/MATERIALS AND METHODS

We included 175 women (aged 49.7 ± 10 years) with newly diagnosed SUI (66% of women) and MUI (34%), respectively. Patients were clinically examined and classified by incontinence types (SUI and MUI) and grades (mild, moderate, severe, and very severe) using International Consultation on Incontinence Modular Questionnaire (ICIQ) and assessing Incontinence Severity Index (ISI). Using Er:YAG laser, we performed on average 2.5 ± 0.5 procedures in each woman separated by a 2 month period. At each session, clinical examination was performed, ICIQ and ISI assessed and treatment discomfort measured with visual analog system (VAS) pain scale, and adverse effects and patients' satisfaction were followed. Follow-ups were performed at 2, 6, and 12 months after the treatment.

RESULTS

After the treatment, ISI decreased for 2.6 ± 1.0 points in patients diagnosed with mild UI before the treatment, for 3.6 ± 1.4 points in those with moderate UI, for 5.7 ± 1.8 points in those with severe UI and for 8.4 ± 2.6 in those with very severe UI (P < 0.001, paired samples t-test). Altogether, in 77% patients diagnosed with SUI, a significant improvement was found after treatment, while only 34% of women with MUI exhibited no UI at one year follow-up. Age did not affect the outcome. No major adverse effects were noticed in either group.

CONCLUSION

The results of our study, have shown that new non-invasive Er:YAG laser could be regarded as a promising additional treatment strategy for SUI with at least one year lasting positive effects. On the other hand, it does not seem appropriate for treating MUI.

Bladder wall thickness in women with symptoms of overactive bladder and detrusor overactivity: Results from the randomised, placebo-controlled shrink study

AIMS

Measurement of bladder wall thickness (BWT) by transvaginal ultrasound (TVUS) may be a less invasive method to diagnose overactive bladder (OAB) or detrusor overactivity (DO) and monitor response to therapy. This study assessed whether treatment with solifenacin affects BWT.

METHODS

This was a double-blind, randomised, placebo-controlled, phase 4 study. Adult women with OAB symptoms received solifenacin 5 or 10 mg or placebo once daily for 12 weeks. The co-primary endpoints were change from baseline to Week 12 in TVUS-measured BWT and urinary nerve growth factor. Only results for BWT are presented here.

RESULTS

Overall, 547 patients were randomised, 501 patients had a baseline BWT measurement, and change from baseline could be calculated for 478 patients. Mean BWT at baseline was 5.08 mm (range 2.2-11.1, SD = 1.14) and was normally distributed. A significant reduction in BWT from baseline to 12 weeks versus placebo was observed with solifenacin 5 mg (-0.42 vs. -0.16 mm, P = 0.03), but not with the 10 mg dose or with pooled solifenacin, considered the primary comparison. Both solifenacin doses were associated with improvements in efficacy and patient satisfaction endpoints versus placebo. Solifenacin was well tolerated, with dry mouth being the most common adverse event.

CONCLUSIONS

There was no consistent effect of solifenacin on BWT in women with OAB/DO, despite improvements in efficacy endpoints. This study suggests that routine clinical assessment of BWT with TVUS for monitoring the effects of OAB/DO treatment is not clinically useful. Neurourol. Urodynam. 35:819-825, 2016. © 2015 Wiley Periodicals, Inc.

Ultrasound thickness of bladder wall in continent and incontinent women and its correlation with cystometry

Objective. To compare bladder wall thickness in two kinds of urinary incontinent women—stress urinary incontinence (SUI) and overactive bladder (OAB) with urodynamic detrusor overactivity (DO), and to compare them with continent patients by ultrasound, also, correlate with cystometric results in incontinent women. Methods. 91 women were divided into the following groups: continent (n = 31), SUI (n = 30), and DO (n = 30) groups after clinical evaluation and urodynamic test (only in incontinent women). Transvaginal ultrasound was performed to the bladder wall thickness (BWT) measurement. The mean of BWT was calculated and data were analyzed with ANOVA and Turkey's multiple comparison tests. Pearson's correlation coefficient (r) was used to compare two variables. Receiver operating characteristic (ROC) curve was performed to study BWT as a diagnostic parameter. Results. BWT in DO group was significantly higher than that in the other groups (P < 0.005). A moderate positive correlation was found between BWT and maximum bladder pressure during involuntary bladder contraction. There was no difference in BWT between SUI and continent groups. DO group had lower first desire to void and cystometric capacity. Maximum bladder pressure at detrusor contraction had a moderate positive correlation with BWT. The ROC revealed an area under the curve of 0.962 (95% CI, 0.90–1.01). Conclusions. DO patients have increased bladder wall thickness, lower first desire to void, and lower cystometric capacity. There was a moderate correlation between BWT and maximum bladder pressure during involuntary bladder contraction.

Review on ultrasound measurement of bladder or detrusor wall thickness in women: techniques, diagnostic utility, and use in clinical trials

PURPOSE

To provide a narrative review of literature evaluating ultrasound techniques for the measurement of bladder wall hypertrophy in women as an alternative to invasive urodynamic assessment for the diagnosis of lower urinary tract symptoms (LUTS).

METHODS

A literature review was performed using PubMed and all paper journals of congress abstracts searching for articles on ultrasound measurement of bladder wall thickness (BWT) or detrusor wall thickness (DWT) published between January 1990 and May 2012. Each study was classified with a level of evidence using the Oxford Centre for Evidence-based Medicine classification (2009).

RESULTS

Ultrasound measurement of bladder wall hypertrophy is not standardised, and techniques vary widely according to anatomical approach, ultrasound frequency and other factors. This review compared transvaginal, translabial/transperineal and suprapubic approaches for ultrasound BWT/DWT measurement. BWT/DWT measurements correlated well with urodynamic diagnoses of detrusor overactivity (DO) using all three ultrasound techniques. BWT values were consistently higher in women with DO than in women with stress incontinence, although threshold values for the differential diagnosis of DO varied between clinical studies (5.0-6.5 mm using transvaginal ultrasound). Few data were available on the use of translabial or suprapubic ultrasound in women. Inter- and intraobserver variability was higher with transperineal and suprapubic ultrasound, and these techniques appear less reliable than transvaginal ultrasound. Studies suggest that BWT is reduced in response to antimuscarinic therapy in women with overactive bladder or DO.

CONCLUSIONS

Data from clinical trials suggest that transvaginal ultrasound measurement of BWT is a reliable method of diagnosing DO in women with LUTS, and BWT decreases during antimuscarinic therapy.

Bladder-wall-thickness ultrasound scan in the investigation of LUTS in women: challenges and limitations

Bladder-wall-thickness (BWT) ultrasound assessment in lower urinary tract conditions has been studied extensively for the last 30 years. There is some evidence that it may have diagnostic utility in detrusor overactivity (DO). The cutoff value for BWT for diagnosing DO is still a matter of debate, with different studies using different values. Transvaginal scanning is the most accurate route of measuring BWT, with excellent interobserver variation and reproducibility. There is still ongoing evaluation of bladder ultrasound and its place in the investigation of overactive bladder symptoms.

Does bladder wall thickness decrease when obstruction is resolved?

INTRODUCTION AND HYPOTHESIS

The aim of the current study was to determine if sonographic bladder wall thickness diminishes after symptomatic obstruction is resolved in female patients after stress incontinence surgery.

METHODS

Between December 2008 and December 2010, 62 female patients with symptomatic bladder outlet obstruction, as defined by Blaivas, who had undergone prior surgery for urinary stress incontinence were included in the study. The patients' history was taken and symptoms were noted. Patients underwent gynaecological examination, and multichannel urodynamic assessment was performed. Vaginal sonographic assessment of the bladder wall thickness (BWT) was performed before and after urethrolysis.

RESULTS

62 patients were included in this study, 55 of whom had undergone suburethral sling insertion and seven had Burch colposuspension. Postoperatively, BWT decreased significantly from 9.1 mm  ±  2.1 to 7.6 mm  ±  2.2 (p < 0.0001). In seven patients, obstruction was still unresolved postoperatively; of these, two had undergone a retropubic sling insertion and two had a Burch colposuspension. An ROC curve analysis showed a significant positive association between residual urine and persistent obstruction before surgery (AUC 0.76, 95%CI 0.58-0.94; p < 0.05).

CONCLUSIONS

If obstruction is resolved, bladder wall thickness decreases. Preoperatively elevated residual urine may increase the risk of persistent obstruction after urethrolysis.

Novel biomarkers for overactive bladder

Biomarkers constitute any objectively measurable indicator of a biological process. The classic biomarker used in the diagnosis of overactive bladder (OAB) has been detrusor overactivity, which is assessed urodynamically. In the search for a reliable, noninvasive alternative to urodynamics, interest has focused on genetic, imaging, and urinary factors. Along with other cytokines detectable in urine, prostaglandin E2 and nerve growth factor are indicators of low-grade inflammation. Although they correlate with OAB symptom severity, they have not been shown to have independent prognostic benefit. Imaging biomarkers have been investigated since the earliest days of video urodynamics. Despite extensive research on the ultrasonographic estimation of bladder wall thickness, further standardization of the technique is required before conclusions can be reached regarding diagnostic accuracy. Genetic factors contribute approximately half of the total risk for urgency incontinence. Functional polymorphisms of the cytochrome P450 IID6 gene significantly alter the metabolism of some commonly used anticholinergic drugs, but no genetic loci that influence risk of OAB have been definitively identified. The first genome-wide association studies for OAB are in progress, and should identify new susceptibility genes. Although current putative biomarkers correlate with OAB severity, much future work is required to assess their prognostic value, and establish their role in clinical practice.