Development of a non-invasive strategy to classify bladder outlet obstruction in male patients with LUTS

[Diagnostic work-up of benign prostatic hyperplasia : The German S2e-guideline 2023 part 1]

BACKGROUND

Lower urinary tract symptoms (LUTS) suggestive of benign prostatic hyperplasia (BPH; in German guidelines: benign prostatic syndrome [BPS]) is the most frequent urological disease in men and can result in a considerable deterioration of quality-of-life. BPS can be associated with LUTS, benign prostatic enlargement (BPE), and bladder outlet obstruction (BOO) or benign prostatic obstruction (BPO), respectively. The expert group on BPS of the German Society of Urology has re-evaluated the tests for the assessment of BPH and provides evidence-based recommendations.

OBJECTIVES

Presentation and evidence-based rating of tests for the assessment of patients with BPS.

MATERIALS AND METHODS

Summary and overview of chapters 5, 6, and 8 of the latest long version of the German S2e guideline on BPS.

RESULTS

The diagnostic work-up should clarify (1) whether the complaints of the patient are caused by BPS, (2) how relevant the complaints are and whether treatment is necessary, (3) whether complications of the lower or upper urinary tract already exist, and (4) which treatment will be most suitable. Baseline assessment should be done in all BPS patients and include history, measurement of LUTS and quality-of-life, urinalysis, serum prostate-specific antigen, post-void residual, ultrasound of the lower urinary tract, including measurements of prostate volume, intravesical prostatic protrusion and detrusor wall thickness, and ultrasound of the upper urinary tract. Additional tests can follow when questions remain unanswered after baseline assessment. These optional tests include bladder diaries, uroflowmetry, serum creatinine, urethrocystoscopy, other noninvasive tests for the determination of BOO/BPO such as penile cuff test, condom catheter method and near-infrared spectroscopy, and other imagining tests such as X‑ray and MRI investigations.

CONCLUSIONS

The updated German S2e guideline summarizes evidence-based recommendations on the diagnostic work-up, including the assessment of the BPS components BPE, LUTS, and BOO/BPO.

Artifacts and abnormal findings may limit the use of asymptomatic volunteers as controls for studies of multichannel urodynamics

BACKGROUND

Multichannel urodynamics is the gold standard for the evaluation of lower urinary tract symptoms (LUTS). When performing studies to validate new adjuncts to urodynamic testing with control patients undergoing urodynamic investigation, there is difficulty in the interpretation of urodynamic results in the asymptomatic patient due to artifacts and the invasive nature of the procedure. The purpose of this investigation was to examine urodynamics in asymptomatic volunteers in order to better understand the role of control participants in urodynamic research studies.

METHODS

Asymptomatic volunteers with no LUTS were recruited to undergo standard urodynamic testing as a comparison group in a study evaluating novel urodynamic techniques. To be eligible, participants had to report no LUTS, score ≤1 on all symptom questions of the International Consultation on Incontinence Questionnaire Overactive Bladder Module (ICIq-OAB) survey, have no medical conditions or to undergo any medications that affect bladder function. The urodynamics was done according to ICS standards. All tracings were evaluated by an expert neuro-urologist. Data were analyzed categorically for the presence or absence of low compliance (<30 mL/cmH20), detrusor overactivity, bladder outlet obstruction (Bladder Outlet Obstruction Index [BOOI]>40), weak contractility (bladder contractility index [BCI]<100), straining to void, poorly sustained detrusor contraction, uncoordinated EMG activity, and intermittent flow.

RESULTS

A total of 24 participants completed the study including 10 men and 14 women. All participants had at least 1 urodynamic abnormality/artifact with an average of 4.43±1.28 abnormalities/participant. The most common abnormalities included uncoordinated electromyography (EMG) activity (87.50%), straining to void (79.17%), and intermittent flow (70.83%). There were no significant differences for sex, age, Body Mass Index.

CONCLUSIONS

This study demonstrated that healthy, asymptomatic volunteers have high rates of abnormal urodynamic findings, suggesting that asymptomatic participants are not the ideal controls in research studies that involve urodynamic testing.

Non-Invasive Predictors of Response to Tamsulosin for Benign Prostatic Obstruction

Objectives

To identify non-invasive predictors of response to tamsulosin 0.4 mg in patients with benign prostatic obstruction (BPO).

Methods

Males ≥ 50 years of age with lower urinary tract symptoms (LUTS) suggestive of BPO for over three months were included in the study. We assessed change in the mean International Prostate Symptom Score (IPSS) and maximum flow rate (Qmax) after six weeks of medical therapy. Clinical and uroflowmetry parameters were compared between two groups of patients with >25% vs. <25% change in the IPSS after treatment. Pre- and post-treatment post-void residue (PVR), Qmax, and IPSS were compared by independent t-test, univariate/multivariate regression analysis.

Results

A total of 121 patients were included. At presentation, the mean prostate size was 35.7±12.2 grams and the mean IPSS was 16.3 ± 4.8. Improvement in the mean IPSS was 7.83, with more marked improvement in storage compared to voiding LUTS (5.26 vs. 2.57). Majority (58%) had a quality of life (QoL) score of 4-5 at presentation whereas after 6-weeks of medication (83.5%) had a QoL score of 0-2. Treatment failure was noted in 11 (9.1%) patients. IPSS was higher and Qmax was lower at the time of presentation in patients who had <25% improvement. However, the two groups were identical on the basis of demographic and other factors (BMI, age, prostate size, PVR).

Conclusion

Moderate LUTS secondary to BPO responds favourably to alpha-blocker (tamsulosin 0.4 mg) treatment. Uroflowmetry (UFM) parameters, that is, Qmax and IPSS are important factors in predicting short-term response to medical therapy.

Comparison of Penile Cuff Test and Conventional Urodynamic Study Prior to Photoselective Vaporization of Prostate for Benign Prostate Hyperplasia Using a 120 W GreenLight High Performance System Laser

Background: We compared the utility of the penile cuff test (PCT) and the conventional urodynamic study (UDS) for the preoperative assessment of patients undergoing scheduled photoselective vaporization of the prostate (PVP) for benign prostate hyperplasia (BPH). Methods: Fifty-nine patients with voiding lower urinary tract symptoms (LUTS) underwent a simultaneous PCT and conventional UDS before PVP. The modified International Continence Society (ICS) nomogram was used to confirm bladder outlet obstruction after measuring maximum urinary flow rate and highest pressure at flow interruption. The PCT and UDS results, in terms of modified ICS nomogram predictions, were compared. Their sensitivities, specificities, and positive and negative predictive values were calculated. Results: Thirty-six patients were diagnosed as obstructed and 23 as non-obstructed/equivocal using the modified ICS nomogram during the PCT. All 36 of the first group were confirmed as obstructed by UDS. Of the 23 diagnosed as non-obstructed/equivocal by the PCT, 14 were confirmed to be non-obstructed by UDS, with nine diagnosed as obstructed. The PCT showed a sensitivity of 80% and a specificity of 100%. The positive and negative predictive values were 100% and 60.9%, respectively. Conclusions: In conclusion, despite our small number of patients, the PCT’s high sensitivity and specificity suggest that it may provide diagnostic information about bladder outlet obstruction before PVP for patients with voiding LUTS. Evidently, the PCT has the potential to be used for some patients as a screening alternative to invasive UDS.

What developments are needed to achieve less-invasive urodynamics? ICI-RS 2019

AIMS

To assess the state of technologies for urodynamics that are less invasive than standard cystometry and pressure-flow studies and to suggest areas needing research to improve this.

METHODS

A summary of a Think Tank debate held at the 2019 meeting of the International Consultation on Incontinence Research Society is provided, with subsequent analysis by the authors. Less-invasive techniques were summarized, classified by method, and possible developments considered. Discussions and recommendations were summarized by the co-chairs and edited into the form of this paper by all authors.

RESULTS

There is a full spectrum of technologies available for less-invasive assessment, ranging from simple uroflowmetry through imaging techniques to emerging complex technologies. Less-invasive diagnostics will not necessarily need to replace diagnosis by, or even provide the same level of diagnostic accuracy as, invasive urodynamics. Rather than aiming for a technique that is merely less invasive, the priority is to develop methods that are either as accurate as current invasive methods, or spare patients from the necessity of invasive methods by improving early triaging.

CONCLUSIONS

Technologies offering less-invasive urodynamic measurement of specific elements of function can be potentially beneficial. Less-invasive techniques may sometimes be useful as an adjunct to invasive urodynamics. The potential for current less-invasive tests to completely replace invasive urodynamic testing is considered, however, to be low. Less-invasive techniques must, therefore, be tested as screening/triaging tools, with the aim to spare some patients from invasive urodynamics early in the treatment pathway.

New Diagnostics for Male Lower Urinary Tract Symptoms

PURPOSE OF REVIEW

Lower urinary tract symptoms (LUTS) is a common constellation of symptoms that affect the aging male population with an astonishing prevalence. New technology and new uses of established technology are being used to help further evaluate LUTS in the male population and help guide treatment options. This review focuses on the developments and future directions in diagnostic modalities for evaluation of male LUTS, focusing on evaluation of both the filling and voiding phases of micturition.

RECENT FINDINGS

New techniques in evaluating the voiding phase include penile cuff test, external pressure sensing condom catheter, ultrasound measurement of detrusor wall thickness, ultrasound measurement of intravesical prostatic protrusion, doppler ultrasound and NIRS technology. Evaluation of the filling phase is still undergoing much development and requires additional validation studies. The techniques undergoing evaluation include sensation meters during UDS, assessing bladder micromotion and wall rhythm, assessing detrusor wall biomechanics, ultrasound measurement of detrusor wall thickness, pelvic doppler ultrasound, as well as functional brain imaging including fNIRS and fMRI.

SUMMARY

The development of novel, non-invasive, diagnostic tools have the potential for better evaluation of LUTS with earlier and enhanced treatments. This will likely improve the quality of life for men with LUTS.

Intravescical prostatic protrusion is a predictor of alpha blockers response: results from an observational study

BACKGROUND

To investigate the efficacy of tamsulosin in patients with lower urinary tract symptoms (LUTS) and benign prostatic enlargement (BPE) with intravesical prostatic protrusion (IPP). Ultrasound measurement of the IPP has been previously described as an effective instrument for the evaluation of benign prostatic obstruction (BPO) and could help in clarifying the role of alpha-blockers in patients with (BPE).

METHODS

Patients with BPE and LUTS were enrolled in this observational study. Intravesical prostatic protrusion was graded as grade 1 (< 5 ml), 2 (5 < IPP < 10 ml) and 3 (> 10 ml). Patients were treated with tamsulosin for twelve weeks. Evaluation was performed before and at the end of treatment by means of International Prostate Symptom Score (IPSS) and uroflowmetry. Patients were considered responders if a reduction of IPSS > 3 points was reported.

RESULTS

One hundred forty-two patients were enrolled. Twelve patients were excluded because of incomplete data. Fifty patients showed an IPP grade 1 (group A), 52 a grade 2 (group B) and 28 a grade 3 (group C). Treatment success was obtained in 82%, 38,5% and 7,1% of patients respectively; these differences (group A vs B-C and group B vs C) were highly significant. The odd ratio to obtain a treatment success was of 59 and 8.1 in group A and group B respectively, in comparison to group C. After a multivariate regression, the relationship between IPP grade and treatment success remained significant. Improvement of uroflowmetry parameters has been reported in all the groups especially in patients with a low grade IPP (p value = 0,016 group A vs group B; p value = 0,005 group A vs group C). Prostate volume seems not to influence this relationship.

CONCLUSIONS

Intravesical prostatic protrusion has found to be significantly and inversely correlated with treatment success in patients with LUTS and BPE under alpha-blockers therapy. Alpha blockers odd ratio of success is 59 times higher in patients with a low grade IPP in comparison to patients with a high grade.

Systematic Review of the Performance of Noninvasive Tests in Diagnosing Bladder Outlet Obstruction in Men with Lower Urinary Tract Symptoms

CONTEXT

Several noninvasive tests have been developed for diagnosing bladder outlet obstruction (BOO) in men to avoid the burden and morbidity associated with invasive urodynamics. The diagnostic accuracy of these tests, however, remains uncertain.

OBJECTIVE

To systematically review available evidence regarding the diagnostic accuracy of noninvasive tests in diagnosing BOO in men with lower urinary tract symptoms (LUTS) using a pressure-flow study as the reference standard.

EVIDENCE ACQUISITION

The EMBASE, MEDLINE, Cochrane Database of Systematic Reviews, Cochrane Central, Google Scholar, and WHO International Clinical Trials Registry Platform Search Portal databases were searched up to May 18, 2016. All studies reporting diagnostic accuracy for noninvasive tests for BOO or detrusor underactivity in men with LUTS compared to pressure-flow studies were included. Two reviewers independently screened all articles, searched the reference lists of retrieved articles, and performed the data extraction. The quality of evidence and risk of bias were assessed using the QUADAS-2 tool.

EVIDENCE SYNTHESIS

The search yielded 2774 potentially relevant reports. After screening titles and abstracts, 53 reports were retrieved for full-text screening, of which 42 (recruiting a total of 4444 patients) were eligible. Overall, the results were predominantly based on findings from nonrandomised experimental studies and, within the limits of such study designs, the quality of evidence was typically moderate across the literature. Differences in noninvasive test threshold values and variations in the urodynamic definition of BOO between studies limited the comparability of the data. Detrusor wall thickness (median sensitivity 82%, specificity 92%), near-infrared spectroscopy (median sensitivity 85%, specificity 87%), and the penile cuff test (median sensitivity 88%, specificity 75%) were all found to have high sensitivity and specificity in diagnosing BOO. Uroflowmetry with a maximum flow rate of <10ml/s was reported to have lower median sensitivity and specificity of 68% and 70%, respectively. Intravesical prostatic protrusion of >10mm was reported to have similar diagnostic accuracy, with median sensitivity of 68% and specificity of 75%.

CONCLUSIONS

According to the literature, a number of noninvasive tests have high sensitivity and specificity in diagnosing BOO in men. However, although the majority of studies have a low overall risk of bias, the available evidence is limited by heterogeneity. While several tests have shown promising results regarding noninvasive assessment of BOO, invasive urodynamics remain the gold standard.

PATIENT SUMMARY

Urodynamics is an accurate but potentially uncomfortable test for patients in diagnosing bladder problems such as obstruction. We performed a thorough and comprehensive review of the literature to determine if there were less uncomfortable but equally effective alternatives to urodynamics for diagnosing bladder problems. We found that some simple tests appear to be promising, although they are not as accurate. Further research is needed before these tests are routinely used in place of urodynamics.

Application of guidelines to the evaluation of the male patient with urgency and/or incontinence

PURPOSE OF REVIEW

To review and evaluate the evidence from contemporary evidence-based guidelines regarding the assessment of men with urinary urgency and/or incontinence.

RECENT FINDINGS

There are a number of evidence-based guidelines which describe the pathways for assessing men with the symptoms of urgency and/or incontinence. We summarize the conclusions of the European Association of Urology, American Urological Association and National Institute of Clinical Excellence guidelines.

SUMMARY

All guidelines recommend a directed history, examination (including digital rectal examination), urinalysis and bladder diary as being essential in the assessment of men with lower urinary tract symptoms, although there are no high levels of evidence studies to support this. Creatinine estimation and prostate-specific antigen are recommended in selected groups of men, the latter after appropriate counselling. Uroflowmetry with postvoid residual assessment is recommended for at specialist assessment. Pad tests may be useful to quantify leakage. Ultrasound assessment of prostatic size and protrusion into the bladder base may be useful. Cystometry is recommended for men considering prostatic surgery, although there is a poor level of evidence underpinning this. Noninvasive surrogates for cystometry, such as penile plethysmography, lack sufficient evidence to allow recommendations to be made.

Assessment of BPH/BOO

The assessment of men with bladder outflow obstruction relies on an adequate history and examination. Uroflowmetry and post-void residue estimation are very revealing and may be sufficient in the majority of men. The prostate-specific antigen test may be used to select men who are at a high risk of progression. In specific situations, cystometry may be required. We discuss the use of cystometry and the newer less-invasive methods of assessment that have emerged over the last few years, including ultrasound estimation of intravesical prostatic protrusion, prostatic urethra angle, detrusor wall thickness, ultrasound-estimated bladder weight, near-infrared spectroscopy and the condom catheter and penile cuff tests. Although these techniques show promise, they still require further modifications, standardization and testing in larger populations. In addition, they should be used in men where only specific questions need to be answered.

Urine flow acceleration is superior to Qmax in diagnosing BOO in patients with BPH

We performed a retrospective, case-control study to evaluate whether the urine flow acceleration (UFA, mL/s(2)) is superior to maximum uroflow (Qmax, mL/s) in diagnosing bladder outlet obstruction (BOO) in patients with benign prostatic hyperplasia (BPH). In this study, a total of 50 men with BPH (age: 58±12.5 years) and 50 controls (age: 59±13.0 years) were included. A pressure-flow study was used to determine the presence of BOO according to the recommendations of Incontinence Control Society (ICS). The results showed that the UFA and Qmax in BPH group were much lower than those in the control group [(2.05±0.85) vs. (4.60±1.25) mL/s(2) and (8.50±1.05) vs. (13.00±3.35) mL/s] (P<0.001). According to the criteria (UFA<2.05 mL/s(2), Qmax<10 mL/s), the sensitivity and specificity of UFA vs. Qmax in diagnosing BOO were 88%, 75% vs. 81%, 63%. UFA vs. Omax, when compared with the results of P-Q chart (the kappa values in corresponding analysis), was 0.55 vs. 0.35. The prostate volume, post void residual and detrusor pressure at Qmax between the two groups were 28.6±9.8 vs. 24.2±7.6 mL, 60.4±1.4 vs. 21.3±2.5 mL and 56.6±8.3 vs. 21.7±6.1 cmH2O, respectively (P<0.05). It was concluded that the UFA is a useful urodynamic parameter, and is superior to Qmax in diagnosing BOO in patients with BPH.

The evidence for urodynamic investigation of patients with symptoms of urinary incontinence

Urodynamic studies are the gold standard to objectively diagnose dysfunction of the lower urinary tract. The widely available evidence for the clinical relevance is, however, fragmented. This article summarizes the published knowledge supporting the use of urodynamic studies in urinary incontinence in female, male and frail patients, as well as patients with relevant neurological disease. Five technological innovations are discussed briefly. Standard urodynamic cystometry can, on the basis of a solid body of evidence, objectively unveil the entire function of the lower urinary tract in all patients with urinary incontinence, regardless of the patients' perception of (ab-)normality of signs and or symptoms.

Longitudinal changes in isovolumetric bladder pressure in response to age-related prostate growth in 1,020 healthy male volunteers

AIM

To non-invasively study if compensation and decompensation occurs in the urinary bladder of healthy male volunteers in response to benign prostatic enlargement (BPE) using the condom catheter method.

METHODS

Between 2001 and 2010, 1,020 healthy male volunteers were included in a longitudinal study based on three non-invasive urodynamic examinations during a 5-year follow-up. Inclusion criteria were an informed consent, the ability to void in a normal standing position and a minimum free flow rate of 5.4 ml/sec. Study parameters were prostate volume (PV), maximum free urinary flow rate (Q(max)) and bladder contractility, quantified by the maximum isovolumetric bladder pressure, measured in the condom (P(cond.max)). Volunteers also completed the International Prostate Symptom Score Form (IPSS).

RESULTS

Within limitations, the included volunteers had a flat age distribution between 38 and 72 years. This made it possible to combine longitudinal analysis in a 5-year observation interval, with cross sectional analysis in a 35-year age range. Longitudinal analysis showed that with increasing age, PV increased with 1.9% per year, whereas Qmax decreased with 1.1% per year. IPSS increased with 1.1% per year when volunteers were older than 55 years. P(cond.max) increased during the 5-year longitudinal follow-up, but not in the cross sectional analysis.

CONCLUSIONS

The difference between cross sectional and longitudinal results of the P(cond.max) may have been caused by compensation of the urinary bladder resulting in a selection effect. This would imply that compensation is a relatively fast process, taking approximately 5 years.

Non-invasive evaluation of bladder outlet obstruction in men suspected of benign prostatic hyperplasia: usefulness of the d index

OBJECTIVE

To compare a new index of voiding dysfunction (D) based purely on free uroflow vs. Abrams-Griffiths (A-G) number obtained from intubated flow, for classification of bladder outlet obstruction in men.

PATIENTS AND METHODS

Urodynamic tracings of 60 non-neurological patients (30 before transurethral resection of the prostate and of 30 men suspected of benign prostatic hyperplasia included in a medical therapy trial) were retrospectively analyzed. The Valentini-Besson-Nelson model was used to evaluate the value of the D index. A-G was obtained from intubated flows. Obstruction was defined as D > 32.5 cm H2O (translation of A-G criterion).

RESULTS

D showed 82.05% sensitivity with 66.66% specificity; the positive predictive value was 82.05% and the negative predictive value 66.66% for the whole population, 83.3 vs. 80.9% sensitivity with 58.3 vs. 77.7% specificity for pre- transurethral resection of the prostate vs. medical therapy group.

CONCLUSION

D index which can be obtained from a free uroflow appears as a valuable alternative to invasive urodynamic investigations when the diagnosis of bladder outlet obstruction needs to be more solidly established before a treatment decision or in men suspected of benign prostatic hyperplasia who elect for watchful waiting.

[Predictive value of the penile cuff-test for the assessment of bladder outlet obstruction in men]

PURPOSE

To assess the diagnostic performances and the acceptability of the penile cuff test (PCT) which is a non invasive method for the evaluation of bladder outlet obstruction (BOO), in comparison with the pressure flow study (PFS), the actual gold-standard.

MATERIAL

Monocentric prospective study comparing the following subsets: "obstructed", "not obstructed" or "equivocal", deduced from PFS vs PCT, in 30 consecutive patients presenting with lower urinary tract symptoms. For the PCT, a cuff placed around the penis inflated automatically during the micturition, until flow rate interruption. The interruption cuff pressure revealed the isovolumetric bladder pressure (Pcuff-int). The data collected - Pcuff-int and maximum flow rate - were automatically reported on ICS modified nomogram.

RESULTS

With the PFS, 11 patients (39%) were classified "obstructed", six patients (22%) "non-obstructed" and 11 patients (39%) "equivocal". In 61% cases, the patient was classified in the same category by both techniques. The "obstructed positive predictive value" of the PCT was 82% and the "non-obstructed-equivocal negative predictive value" was 88%. The median acceptability visual analogic scale score was 1/10 (0-3) for the PCT whereas it was 5/10 (2-10) for the PFS. This difference was statistically significant (p=0.004).

CONCLUSION

The PCT was a reliable non-invasive tool for the diagnosis of BOO in male, in comparison with PFS. The predictive values of the PCT were relevant and its tolerance was better than PFS.

Continuous non-invasive measurement of bladder voiding pressure using an experimental constant low-flow test

PURPOSE

We developed a prototype device using an automatically controlled inflatable penile cuff to measure bladder voiding pressure continuously and non-invasively in men. The purpose of this study was to validate the pressure measurements made by this device by comparison to those during simultaneous invasive PFS.

METHODS

A device was developed to automatically modulate flow rate by controlling pressure in a penile cuff. Men undergoing conventional urodynamics studies were recruited to have an additional fill-void cycle whilst using the new device. We report on 40 men using a standardized protocol. Pressure measured by this device was compared with simultaneous vesical pressure by evaluating maximum pressure during voiding, and calculating the root mean square (RMS) difference between p(cuff) and p(ves) .

RESULTS

We recruited 80 men of whom 18 were excluded, 22 were involved in initial development phase and 40 in the standard protocol. Mean (SD) difference between maxima of p(cuff) and p(ves) (1.3 (15.6) cmH(2) O) was not significant. In 20 (50%) men, agreement between p(cuff) and p(ves) throughout the void was moderate or good (RMS difference <20 cmH(2) O). Causes of unsuccessful measurements were identified.

CONCLUSIONS

Although a prototype device, this technique appears to be promising for continuous non-invasive bladder pressure measurement. From the results of this study a number of improvements have been recommended and implemented. The next generation of this technique will allow assessment of clinical application.

Development and application of the condom catheter method for non-invasive measurement of bladder pressure

Objectives:

A non-invasive method to measure the bladder pressure in males using a condom catheter has been developed. The measurement technique, its validation and limitations, a diagnostic nomogram to non-invasively diagnose bladder outlet obstruction (BOO), and results of large-scale application are discussed.

Methods:

Modified incontinence condoms are attached to the penis. During voiding the flow of urine is mechanically interrupted. The subsequent maximum pressure in the condom reflects the isovolumetric bladder pressure. The method was validated in a group of 46 patients with lower urinary tract symptoms who were simultaneously studied invasively and non-invasively. Subsequently it was applied in a non-invasive epidemiological study in 1020 healthy males.

Results:

The reproducibility of the measured isovolumetric bladder pressure is comparable to that of conventional pressure-flow parameters. The measured pressure can be used to diagnose bladder outlet obstruction with a diagnostic accuracy (Area Under receiver operator characteristic curve) of 0.98, which compares most favorably with the area under the curve of 0.79 of Q_max in the same population. During condom catheter measurements, both the involuntary interruption of voiding and the forced diuresis increase post-void residual volume. This increase does not affect the accuracy of the pressure measurements.

Conclusions:

We conclude that in males bladder pressure can successfully be measured non-invasively using the condom catheter method. By combining the measured volumetric bladder pressure with a separately measured free flow rate, BOO can non-invasively and accurately be diagnosed.

Executive summary: The International Consultation on Incontinence 2008--Committee on: "Dynamic Testing"; for urinary incontinence and for fecal incontinence. Part 1: Innovations in urodynamic techniques and urodynamic testing for signs and symptoms of urinary incontinence in female patients

AIMS

The members of The International Consultation on Incontinence 2008 (Paris) Committee on Dynamic Testing' provide an executive summary of the chapter 'Dynamic Testing' that discusses (urodynamic) testing methods for patients with signs and or symptoms of urinary incontinence. Testing of patients with signs and or symptoms of faecal incontinence is also discussed.

METHODS

Evidence based and consensus committee report.

RESULTS

The chapter 'Dynamic Testing' is a continuation of previous Consultation-reports added with a new systematic literature search and expert discussion. Conclusions, based on the published evidence and recommendations, based on the integration of evidence with expert experience and discussion are provided separately, for transparency.

CONCLUSION

This first part of a series of three articles summarizes the committees recommendations about the innovations in urodynamic study techniques 'in general', about the test characteristics and normal values of urodynamic studies as well as the assessment of female with signs and or symptoms of incontinence and includes only the most recent and relevant literature references.

The Role of Non-Invasive Urodynamics in Bladder Outlet Obstruction Diagnosis in Male Patients

Purpose

Many Methods have been suggested to assess bladder outlet obstruction, as defined by the gold standard of pressure flow studies. A comprehensive review of the literature on the different methods used to diagnose bladder outlet obstruction by non-invasive means was performed in order to compare those methods to invasive urodynamics in terms of sensitivity and specificity.

Materials and Methods

A MEDLINE search was done of the published literature covering from December 2003 on non-invasive methods, including only single measures to diagnose bladder outlet obstruction. We performed a comparison between all methods in terms of sensitivity and specificity for each test. For many techniques these values were calculated directly from the data presented in the article.

Results

There has been applied many methods to diagnose bladder outlet obstruction. Those methods were divided into uroflowmetry condom-catheter method, penile cuff method and Doppler ultrasonography urodynamics. Each method has been described and discussed in terms of its role in adding information to the diagnostic work-up for bladder outlet obstruction.

Conclusions

Pressure flow studies still remain the gold standard for assessing bladder outlet obstruction. However non-invasive urodynamics is a promising branch. Probably the most reliable information is given by the association of numerous methods together.

A novel intraurethral device diagnostic index to classify bladder outlet obstruction in men with lower urinary tract symptoms

Objectives. Using a urethral device at the fossa navicularis, bladder pressure during voiding can be estimated by a minimal invasive technique. This study purposes a new diagnostic index for patients with lower urinary tract symptoms (LUTSs). Methods. Fifty one patients presenting with LUTSs were submitted to a conventional urodynamic and a minimal invasive study. The results obtained through the urethral device and invasive classic urodynamics were compared. The existing bladder outlet obstruction index (BOOI) equation that classifies men with LUTSs was modified to allow minimal invasive measurement of isovolumetric bladder pressure in place of detrusor pressure at maximum urine flow. Accuracy of the new equation for classifying obstruction was then tested in this group of men. Results. The modified equation identified men with obstruction with a positive predictive value of 68% and a negative predictive value of 70%, with an overall accuracy of 70%. Conclusions. The proposed equation can accurately classify over 70% of men without resorting to invasive pressure flow studies. We must now evaluate the usefulness of this classification for the surgical treatment of men with LUTSs.

New method for minimally invasive urodynamic assessment in men with lower urinary tract symptoms

OBJECTIVES

Urodynamic studies are considered the reference standard to diagnose bladder outlet obstruction. However, the procedure is invasive, expensive, and time-consuming. The purpose of this study was to evaluate a new minimally invasive urodynamic assessment model and compare the results with those of conventional urodynamic evaluation.

METHODS

The study included 50 male patients who presented with lower urinary tract symptoms. Their mean age was 62 years (range 34 to 82). After undergoing a conventional urodynamic study, they underwent the minimally invasive evaluation. The urethral device is a conical apparatus that adapts to the urethral meatus and fossa navicularis. The isometric bladder pressure and interrupted flow were recorded. The results of the conventional assessment were classified according to the Abrams-Griffiths number and a logistic regression fit was applied to the minimally invasive method.

RESULTS

Only two variables demonstrated the predictive capacity: the isometric pressure and interrupted flow. In addition to selecting the relevant variables, logistic regression analysis is a more adequate model that provides a binary result of obstructed and unobstructed, used to predict the normal and equivocal categories of the Abrams-Griffiths classification, and taken as the reference standard. The sensitivity and specificity of the new method was 67% and 79%, respectively.

CONCLUSIONS

The urethral device proved to be simple and easy to use. The minimally invasive method was able to detect most patients with bladder outlet obstruction; thus, the conventional urodynamic assessment could be avoided. We consider this method to have a place as a first-line noninvasive examination.

Role of UPP in evaluating bladder outlet obstruction due to benign prostatic enlargement

AIMS

To study the role of UPP in assessing bladder outlet obstruction (BOO) due to benign prostatic enlargement (BPE).

MATERIALS AND METHODS

Urodynamic results from 1281 elderly men with Lower urinary tract symptoms (LUTS) obtained from September 1999 through July 2005 were retrospectively analyzed. Independent sample t-test or Wilcoxon signed-rank test was used to compare the parameters of different groups according to PFS. Chi-square test was used to compare the percentage of urethral pressure profile (UPP) types between different groups. ROC curve was used to study the practical value of UPP parameters in diagnosing BOO.

RESULTS

According to PFS, patients were divided into three groups: Obstructed, equivocal obstructed and unobstructed. There was significant difference between the unobstructed and obstructed group in the age of patients, bladder capacity, residual volume, voided volume, voided time, prostatic plateau area (PPA), prostatic length, functional profile length, pressure of bladder neck, and pressure of seminal colliculus, but not in maximum urethral closure pressure. All UPP parameters correlated significantly to the diagnosis of bladder outlet obstruction due to BPE. The largest area under the ROC curve was that of PPA.

CONCLUSIONS

Our results indicate that PPA on UPP is useful in assessing the grade of obstruction due to BPE when PFS fails, a finding still to be evaluated by prospective studies.

Is it possible to improve elderly male bladder function by having them drink more water? A randomized trial of effects of increased fluid intake/urine output on male lower urinary tract function

OBJECTIVES

Several animal studies have shown that bladder performance improves as a result of diuresis. Whether increased urine output also has beneficial effects on elderly male bladder function and lower urinary tract symptoms is unknown.

METHODS

We performed a randomized placebo-controlled trial of 141 men, 55 to 75 years of age, with moderate lower urinary tract symptoms. The experimental group drank 1.5 L of extra water daily. The control group consumed one tablespoon of placebo syrup daily. After 6 months, we evaluated bladder contractility, voided volumes, and the severity of lower urinary tract symptoms. The actual increase in water consumption was measured using the deuterium urine dilution method.

RESULTS

Water consumption in the intervention group increased by 359 mL (95% confidence interval [CI] 171 to 548) per 24 hours compared with the control group. At 6 months, no statistically significant effect was found in the maximal flow rate (0.9 mL/s, 95% CI -0.4 to 2.2) compared with placebo. A statistically significant effect was found for bladder pressure (20 cm H2O, 95% CI 6 to 34) and bladder wall stress (1.9 N/cm2, 95% CI 0.3 to 3.5). In addition, it showed that the experimental group had greater maximal (44 mL, 95% CI -1 to 90) and average (26 mL, 95% CI 1 to 51) voided volumes per urination. The subjective effect parameters improved in both groups, but no statistically significant differences were found between the two groups.

CONCLUSIONS

It seems possible to improve some aspects of male bladder function by drinking more water. However, the effects are too small to be clinically relevant.

Noninvasive methods of diagnosing bladder outlet obstruction in men. Part 2: Noninvasive urodynamics and combination of measures

PURPOSE

Many methods have been suggested to diagnose bladder outlet obstruction, as defined by the gold standard of pressure flow studies. Difficulty arises when comparing completely different methods of diagnosing bladder outlet obstruction. A comprehensive review of the literature on the different methods used to diagnose bladder outlet obstruction by noninvasive means was performed with a view to allow such a comparison.

MATERIALS AND METHODS

A MEDLINE search was done of the published literature covering until the end of 2004 on noninvasive methods, including single measure and combinations of measures, to diagnose bladder outlet obstruction. A direct comparison of all of the different methods was made using the sensitivity, specificity, likelihood ratio, and pretest and posttest probability of diagnosing bladder outlet obstruction for each test. For many techniques these values were calculated from the data presented in the article.

RESULTS

A multitude of methods has been applied to diagnose bladder outlet obstruction. Broadly the methods were divided into nonurodynamic and noninvasive urodynamic methods. Nonurodynamic methods were considered in part 1 of the review. Part 2 considered noninvasive urodynamic techniques, such as uroflowmetry, the penile cuff, the condom method and Doppler urodynamics. A combination of single measures was also considered and the relative merits of these approaches were discussed.

CONCLUSIONS

A combination of noninvasive urodynamics and ultrasound derived measures provide promising methods of diagnosing bladder outlet obstruction. However, pressure flow studies still remain the gold standard for assessing bladder outlet obstruction.

[Non-invasive urodynamics in male patient]

PURPOSE

Pressure-flow studies are currently recognized as the criterion standard to quantify urethral obstruction and its consequence on detrusor contractility. These tests have some disadvantages: they are invasive, time-consuming and expensive and entail risk of disease for the patient. Less invasive methods have been proposed to give the same results without the disadvantages. In this study, we conducted a critical analysis of the devices and techniques and their results.

METHOD

After a brief reminder of the general behavior of the flow in an obstructed urethra, we describe the main non-invasive techniques: penile urethral compression-release (PCR), cuffs, and condoms. Using the VBN method, we tried to quantify data from these techniques to specify the relation with the usual parameters of bladder outlet obstruction.

RESULTS

In the absence of brisk change of the flow rate, the voiding phases are easily analyzed. With minor corrections, recorded external or cuff pressures could be used in the ICS nomogram; unfortunately, these pressures are greatly modified by perturbations of the nervous control. The spike of flow (due to urine storage in the urethra) observed at resumption of flow after each interruption presents mathematical difficulties for quantitative and reliable modeling but could give a consistent empirical interpretation.

CONCLUSION

Of the reported non-invasive tests, all except PCR have an important instrumental heaviness and induce strong perturbations of the nervous control. If they cannot allow an accurate quantification of urethral obstruction and detrusor contractility, they could allow for classification of benign prostatic hypertrophy (BPH) patients. Despite the mathematical problems set by the theory of spikes, the empirical use of the spikes amplitude could perhaps be clinically useful.

Correlation of non-invasive urodynamics with International Prostate Symptom Score (IPSS) and prostate volume

AIM

To study the correlation between non-invasive urodynamic data, the International Prostate Symptom Score (IPSS) and the prostate volume.

MATERIALS AND METHODS

Data of 667 healthy volunteers participating in a longitudinal study of changes in urinary bladder contractility secondary to BPE were analyzed. The prostate volume was assessed by transabdominal ultrasonography. Uroflowmetry followed to verify if a minimum free flow rate of 4.5 ml/sec could be achieved. While (re)filling the bladder by drinking, the subjects completed the Dutch version of the IPSS. Next, the bladder pressure was non-invasively measured using the condom catheter method. The urethral resistance (URR) was calculated from the maximum condom pressure and the maximum free flow rate.

RESULTS

The IPSS ranged from 0 to 29, (6.1 +/- 4.8) (mean +/- SD), whereas the prostate volumes ranged from 8 to 140 cm3, (34 +/- 18). Twenty eight percent (185/667) of the subjects had a non-invasively quantified high URR and a significantly higher IPSS (7.3 +/- 5.2) than those with a low URR (IPSS (5.7 +/- 4.6)), Mann-Whitney U-test: P < 0.001. The IPSS and the URR were significantly correlated, Spearman's rho (rho) = 0.20, P < 0.001. A significant difference between the prostate volumes, 36 +/- 21 cm3 in the high URR versus 33 +/- 17 cm3 in the low URR group, was not found, P = 0.18.

CONCLUSIONS

A weak though statistically significant correlation was found between the non-invasively quantified URR and the IPSS. This suggests that an elevated resistance is a necessary, but not a sufficient condition for lower urinary tract symptoms (LUTS). No correlation was found between the URR and the prostate volume.

Comparison of repeatability of non-invasive and invasive urodynamics

AIMS

We have developed a method for the non-invasive measurement of urinary bladder pressure, and we apply this method in a longitudinal study of changes in bladder contractility in response to prostatic enlargement. In each volunteer in this study, we measure the bladder pressure twice. In the present study we have used this data to compare the repeatability of the non-invasive method to that of pressure-flow studies in a comparable population of patients.

METHODS

Difference plots were made of non-invasive bladder pressure measurements in 457 volunteers and of pressure-flow studies in a comparable population of 397 male patients. To compare the repeatability of two different methods for clinical measurement, the standard deviation of differences between repeated measurements in one individual needs to be normalised. Often a normalisation by dividing by the mean is done. We show that that normalisation may lead to erroneous results. We have normalised the standard deviations by dividing by the difference between the 97.5th and 2.5th percentile of the mean of the two observations in each subject.

RESULTS

Normalised repeatability of the non-invasive method was 0.15, that of the various parameters derived from the pressure-flow studies varied from 0.11 to 0.22.

CONCLUSIONS

We conclude that the repeatability of the tested non-invasive urodynamic method is comparable to, or slightly better than, that of pressure-flow studies. We further conclude that normalising standard deviations of differences by dividing by the difference between the 97.5th and 2.5th percentile of the mean is a suitable method to compare the repeatability of different methods for clinical measurement.

Applicability and reproducibility of condom catheter method for measuring isovolumetric bladder pressure

OBJECTIVES

To report on the applicability, reproducibility, and adverse events of the noninvasive condom catheter method in the first 730 subjects of a longitudinal survey of changes in urinary bladder contractility secondary to benign prostatic hyperplasia, in which 1300 men will be evaluated three times in 5 years using this method.

METHODS

Subjects were recruited by general practitioners, general publicity, and e-mail. Only those meeting the study criteria were entered in the study. If the free flow rate exceeded 5.4 mL/s, at least two consecutive condom pressure measurements were attempted using the condom catheter method. The condom pressure measured reflected the isovolumetric bladder pressure, a measure of urinary bladder contractility. The reproducibility of the method was quantified by a difference plot of the two maximal condom pressures measured in each subject.

RESULTS

In 618 (94%) of 659 eligible participants, one condom pressure measurement was completed; two measurements were done in 555 (84%). The maximal condom pressure ranged from 28 to 228 cm H2O (overall mean 101, SD 34). A difference between the two pressures of less than +/-21 cm H2O was found in 80%. The mean difference was -1 cm H2O (SD 18), significantly different from 0. Some adverse events such as terminal self-limiting hematuria were encountered.

CONCLUSIONS

The condom catheter method is very suitable for large-scale use. It has a success rate of 94% and a reproducibility comparable to that of invasive pressure flow studies.

Noninvasive Techniques for the Measurement of Isovolumetric Bladder Pressure

PURPOSE

A total of 184,000 prostatectomies were performed in the United States in 2000 for the relief of presumed bladder outlet obstruction. However, it has been reported that prostatectomy using current indications fails to bring about symptomatic improvement in approximately one-fourth of patients. Pressure flow studies are currently recognized as the gold standard for the diagnosis of bladder outlet obstruction. However, these studies are associated with a number of disadvantages. They are time consuming, invasive and expensive, and carry some morbidity for the patient. It has been suggested that the use of pressure flow studies should be mandatory before surgery. The invasive nature of this test limits its application, and a variety of noninvasive methods have been suggested to circumvent the need for conventional urodynamics.

MATERIALS AND METHODS

We conducted a MEDLINE search of the published literature on the use of noninvasive techniques to measure bladder pressure.

RESULTS

Two promising techniques involve the noninvasive measurement of isovolumetric detrusor pressure. The first of these methods uses an external condom catheter and the second an inflatable cuff around the penis. Both of these methods rely on the interruption of urinary flow and the measurement of the bladder pressure transmitted along the fluid column between bladder and site of urethral occlusion. An alternative strategy analyzes flow patterns following compression and release of the urethra during voiding.

CONCLUSIONS

Of the methods reported the penile cuff, which is inflated during voiding, or the penile squeeze technique, which infers bladder pressure from flow patterns, would seem the most likely to be clinically useful. A noninvasive measure of bladder pressure, allied to a free flow rate, would give a useful adjunct to the assessment of men with lower urinary tract symptoms.

Diagnosis and treatment of voiding symptoms

Lower urinary tract symptoms (LUTS) are associated with lower urinary tract dysfunction. Symptoms are the subjective indicator of a disease or change in condition as perceived by the patient, caregiver, or partner and may lead the individual to seek help from health care professionals. LUTS are usually qualitative and, therefore, cannot usually be used to make a definitive diagnosis. LUTS also can indicate pathologies other than lower urinary tract dysfunction, such as urinary infection. LUTS are divided into 7 groups: storage, voiding (obstructive), postmicturition symptoms and 4 others. Voiding symptoms, which are caused by lower urinary tract obstruction, include slow stream, splitting or spraying, intermittency, hesitancy, straining, and terminal dribble. Postmicturition symptoms, which are experienced immediately after micturition, consist of the feeling of incomplete emptying and postmicturition dribble. Postmicturition dribble describes the involuntary loss of urine immediately after the individual has finished passing urine; in men, usually after leaving the toilet and in women, after rising from the toilet. Hence, postmicturition dribble is elicited by different situations or is considered as having different implications. For example, although postmicturition dribble usually implies incomplete emptying (voiding symptoms) in elderly men with benign prostatic hyperplasia, postmicturition dribble is often considered as urinary incontinence (a storage symptom) in many patients, even with bladder outlet obstruction. In such cases, detailed history taking and further evaluation, such as urinary flowmetry, postvoid residual volume, and comprehensive urodynamic evaluation, should be performed as appropriate. If no urodynamic abnormalities of either the detrusor or the outlet can be detected despite significant LUTS, factors unrelated to the lower urinary tract may be responsible for the voiding symptoms.

Relationship of abdominal pressure and body mass index in men with LUTS

AIMS

In the development of a non-invasive method for estimating isovolumetric intravesical pressure (pves,isv) we looked for a relationship between intra-abdominal pressure (pabd) and general build, expressed as body mass index (BMI) in men with lower urinary tract symptoms (LUTS).

MATERIALS AND METHODS

In 100 consecutive male patients undergoing an invasive pressure flow study (PFS) the pabd was recorded continuously during filling and voiding. The magnitude at four set points was measured: before filling, after filling, during voiding and at the end of voiding. Patients' weight (kg) and height (m) were also recorded and their BMI (weight/height(2)) was calculated.

RESULTS

During the fill/void cycle pabd increased during bladder filling from 37 +/- 7 cm H2O (mean +/- SD) to 38 +/- 8 cm H2O, fell during voiding to 35 +/- 9 cm H2O before increasing to 36 +/- 8 cm H2O at the end of voiding. There was a clear relationship between the individual values of pabd and BMI (correlation co-efficient = 0.52) and to a lesser extent weight (correlation co-efficient = 0.42). The relationship with BMI was clarified by separating the subjects into groups of normal, overweight and obese.

CONCLUSIONS

A clear relationship between BMI and pabd was demonstrated, but because of the difficulties in quantifying it for an individual, it is impractical to apply an adjustment to non-invasive estimates of pves,isv.

[Overactive bladder--which diagnosis investigations are necessary before initiating primary treatment?]

The symptom complex of frequency and urgency with or without urge incontinence is termed overactive bladder (OAB) according to the new definition by the International Continence Society. The background for this change in definition is the great economic and social importance of the disease, the rising costs in medicine, and the tendency to develop the simplest possible therapeutic strategies. Therapy consists of the administration of an anticholinergic/spasmolytic drug for at least 3 months. Although a great percentage of patients with OAB can be clinically identified, the required exclusion of "local pathologic and metabolic factors" calls for a minimal diagnostic program to come to fairly exact findings. This includes a detailed case history with standardized and evaluated questionnaires, a bladder diary, detailed clinical examination, urine analysis consisting of microscopic and microbiologic examination, uroflowmetry including measurement of residual urine, and examination of the kidneys and the upper urinary tract (determination of creatine and sonography). Minimally invasive tests to improve validity regarding obstruction and detrusor overactivity are being developed. These tests are intended to make an invasive pressure-flow study unnecessary. However, using the above-described minimal diagnostic program, one has to take into account that patients suffering from complaints without underlying idiopathic detrusor overactivity and with urgency/urge incontinence due to bladder outlet obstruction are referred for primary therapy with anticholinergic/antispastic drugs. In cases of neurologic signs, pathologic urinary findings, reduced urinary flow rate with residual urine, and problems of the upper urinary tract, further diagnostic studies are necessary. In any case, such patients need not undergo primary therapy on the basis of a clinical diagnosis. An ex iuvantibus therapy with anticholinergic drugs--even if limited to 3 months--is not acceptable if the diagnostic minimal program is not used.