Standardization of terminology of lower urinary tract function: pressure-flow studies of voiding, urethral resistance, and urethral obstruction. International Continence Society Subcommittee on Standardization of Terminology of Pressure-Flow Studies

Comparison of voiding parameters in men and women with lower urinary tract symptoms

AIM

The aim of this study was to compare voiding parameters by using urodynamic investigations in men and women with lower urinary tract symptoms (LUTS).

METHODS

A total of 164 individuals (76 men and 88 women) completed the International Prostate Symptom Score (IPSS) and underwent a detailed urodynamic investigation. Patients were stratified by voiding function, which included bladder voiding efficiency (BVE) of < 80% and of >or= 80%.

RESULTS

IPSSs were similar in the men and women except for voiding symptoms for those with a BVE of >or= 80% (12 for men vs. 9 for women, P=0.016). When voiding parameters were compared according to BVE in men and women, respectively, maximum flow rate (Q(max)) (P=0.002), average flow rate (Q(ave)) (P=0.003), voided volume (P=0.037), post-void residual (PVR) (P<0.001), and bladder outlet obstruction index (P=0.016) were different for men with a BVE of < 80% and men with a BVE of >or= 80%. However, for women with a BVE of < 80% or >or= 80%, PVR (P<0.001), detrusor pressure at maximum flow rate (P=0.022), and opening detrusor pressure (P=0.024) were different.

CONCLUSIONS

The voiding parameters of women differ from those of men according to voiding function. The present results show that a pressure-flow study may represent a difference according to BVE in women as well as in men. Our findings suggest that opening detrusor pressure in women reflects the urethral and detrusor during voiding phase accurately as detrusor pressure at maximum flow rate does.

The natural history of lower urinary tract dysfunction in men: the influence of detrusor underactivity on the outcome after transurethral resection of the prostate with a minimum 10-year urodynamic follow-up

OBJECTIVES

To assess the long-term outcome of the efficacy of transurethral resection of the prostate (TURP) in men with detrusor underactivity (DUA), a cause of lower urinary tract symptoms (LUTS) in a significant minority of men.

PATIENTS AND METHODS

Neurologically intact men with LUTS, who were investigated in our department between 1972 and 1986, diagnosed with DUA and who underwent surgical intervention, were invited for a repeat symptomatic and urodynamic assessment. Identical methods were used, allowing direct comparison of the results.

RESULTS

In all, 224 men were initially diagnosed with DUA; 87 (39%) of these died in the interim and 22 followed had a TURP, with a mean follow-up since surgery of 11.3 years. There were no significantly sustained reductions in any symptoms. There was a small but significant reduction of questionable clinical significance in the bladder outlet obstruction index, but this did not translate into an improved flow rate. Comparison with 58 age-matched patients with DUA who remained untreated showed no significant advantage of surgical intervention in the long-term; on the contrary, there was more chronic retention in those who had had surgery.

CONCLUSIONS

There are no long-term symptomatic or urodynamic gains from TURP in men shown to have DUA. The results of TURP in men with DUA are important, as urologists who surgically treat patients based on the symptoms and uroflowmetry alone will do so in a significant minority of men with DUA. These results strengthen the argument for a routine preoperative urodynamic assessment.

Noninvasive assessment of prostatic obstruction in elderly men with lower urinary tract symptoms associated with benign prostatic hyperplasia

OBJECTIVES

To investigate what combination of easily available parameters allows the noninvasive prediction of infravesical obstruction in optimal agreement with urodynamic classification. Urodynamically, men with lower urinary tract symptoms suggestive of benign prostatic hyperplasia are classified as nonobstructed or obstructed.

METHODS

Mandatory and recommended tests were performed in 160 consecutive men with lower urinary tract symptoms suggestive of benign prostatic hyperplasia. The classification of the International Continence Society, the group-specific urethral resistance factor, and Schäfer's obstruction grade were estimated from urodynamic studies. The frequency-volume charts were analyzed. A separate group of 173 consecutive men was used for validation.

RESULTS

The formula, prostate volume (in cubic centimeters) - 3 x maximal urinary free flow rate (in milliliters per second) - 0.2 x mean voided volume (in milliliters; as estimated from frequency-volume charts), was optimal in the classification compared with the urodynamic classification. Extension of this formula to more than three parameters did not result in better selection. As estimated from receiver operating characteristic curves, the accuracy of the formula appeared to be good. The method of quantifying urethral resistance minimally affected the classification that resulted from the combination. From the results, a diagram was created presenting the probability of an individual to have infravesical obstruction. The validation results were satisfactory.

CONCLUSIONS

The prediction of the probability of a man with lower urinary tract symptoms suggestive of benign prostatic hyperplasia to have infravesical obstruction can be deduced from a diagram based on a formula composed of three readily available parameters: prostate volume, maximal urinary free flow rate, and mean voided volume.

Positive response to ice water test associated with high-grade bladder outlet obstruction in patients with benign prostatic hyperplasia

OBJECTIVES

To elucidate the clinical significance of detrusor overactivity (DO) that is probably due to C-fiber activation caused by bladder outlet obstruction (BOO), we examined the responses to the ice water test (IWT) in patients with benign prostatic hyperplasia (BPH) and assessed the results with reference to the clinical manifestations and urodynamic findings.

METHODS

A total of 127 patients without neurologic disease, who were older than 50 years of age, with an International Prostate Symptom Score of 8 points or greater and a quality of life index of 2 or more points, were enrolled in this study. We tested the response to ice water instillation by monitoring the intravesical pressure in all cases and assessed the results with reference to the findings of International Prostate Symptom Score and quality of life index questionnaires, BOO indexes, 48-hour frequency volume charts, prostate volume, and data from free-flowmetry and pressure flow studies for detecting DO. Twenty patients with neurogenic bladder dysfunction underwent IWT as a control group.

RESULTS

The responders to the IWT accounted for 14 (70%) of the 20 patients with neurogenic bladder dysfunction and 35 (27%) of the 127 patients without neurologic disease. All of these responders showed DO on the pressure flow studies. The patients without neurologic disease who responded to the IWT had higher BOO indexes than did the nonresponders and had a smaller volume at a maximal desire to void on the urodynamic studies. The largest single-voided volume recorded from the 48-hour frequency volume charts was also smaller for the responders than for the nonresponders.

CONCLUSIONS

The patients with BPH clearly showed that DO was mainly due to active C-fibers stimulated by high-grade BOO and that DO was a cause of urgency and frequency-related symptoms with decreased bladder capacity. It will be necessary to assess the inhibitory effect of capsaicin on DO caused by activation of C-fibers and the reversibility of C-fiber activation after surgical treatment for BPH, so that the criteria for decision-making for the treatment of BPH may be clarified with the aid of the IWT.

Weak correlation between bladder outlet obstruction and probability to void to completion

OBJECTIVES

To investigate the weak correlation between bladder outlet obstruction (BOO), as diagnosed using the provisional International Continence Society nomogram for the definition of BOO in men, and postvoid residual urine volume.

METHODS

The relationship between voiding to completion and several indexes for bladder outlet resistance and bladder contractility was studied in 131 pressure flow studies in male patients using multivariate logistic regression analysis.

RESULTS

The International Continence Society nomogram and the related BOO index weakly predict for postvoid residual urine volume (areas under the receiver operating characteristic curve 0.63 and 0.64, respectively). The BOO index primarily measures bladder outlet resistance. If the nomogram or BOO index is augmented with bladder contractility information, the postvoid residual urine volume can be predicted significantly better (eg, area under the receiver operating characteristic curve [0.89] for the combination of the BOO index and bladder contractility information).

CONCLUSIONS

The weak correlation between BOO and postvoid residual urine volume is related to the fact that emptying the bladder to completion depends on bladder contractility, as well as bladder outlet resistance. It is possible to estimate the probability to void to completion quite accurately on the basis of bladder outlet resistance and bladder contractility. We named this probability "relative bladder outlet resistance." A high probability of a postvoid residual urine volume may be assumed to indicate "relative BOO." By its very nature, the correlation between "relative BOO" and postvoid residual urine volume is good.

Comparison of outcomes of transurethral prostate resection in urodynamicallyobstructed versus selected urodynamicallyunobstructed or equivocal men

OBJECTIVES

To compare the benefits of transurethral resection of the prostate in urodynamically obstructed versus selected urodynamically unobstructed or equivocal men with severe lower urinary tract symptoms associated with benign prostatic enlargement.

METHODS

In this case series study, men with lower urinary tract symptoms were selected if they met the study criteria and underwent the tests recommended by the International Scientific Committee on Benign Prostatic Hyperplasia. They also underwent urodynamic investigations. Men were included when transurethral resection of the prostate was selected as the treatment modality. Of the 132 included subjects, 93 could be re-evaluated 6 months after surgery.

RESULTS

Of the 93 re-evaluated men, 59 were obstructed and 34 were unobstructed or equivocal. Both groups were similar with respect to age, symptoms, bother, benign prostatic hyperplasia-impact index, and quality of life. The quantified reductions in symptoms and bother in the unobstructed and equivocal men were about 70% of those reductions in the obstructed men. In the equivocal men, and even in the unobstructed men, a significant reduction with 40% of the urethral resistance occurred.

CONCLUSIONS

Transurethral resection of the prostate may be a good treatment alternative for unobstructed or equivocal men with severe lower urinary tract symptoms associated with prostatic enlargement, who opt for resection or who do not respond to or do not tolerate medical therapy.

Effectiveness of intravesical resiniferatoxin for anticholinergic treatment refractory detrusor overactivity due to nonspinal cord lesions

PURPOSE

Evidence suggests that unmyelinated C fibers become predominant in the mediation of the detrusor reflex in patients with chronic spinal cord lesions and possibly in idiopathic detrusor hyperactivity. Intravesical vanilloid therapy might be effective in treating refractory detrusor overactivity due to nonspinal cord lesion. This study investigated the clinical effect of intravesical resiniferatoxin in treating detrusor overactivity of nonspinal cord lesions refractory to anticholinergics.

MATERIALS AND METHODS

A total of 41 patients received intravesical resiniferatoxin therapy with 10 ml of 100 nM resiniferatoxin in 10% ethanol solution for 40 minutes. The clinical effects on a decrease in incontinence episodes and urodynamic study were evaluated at baseline and after treatment. Clinical improvement was considered if patients became dry or had a decrease in incontinence episodes of 50%. Therapeutic results were analyzed by disease category and type of initial detrusor response.

RESULTS

Of the 41 patients 10 had neurogenic lesions, 18 had previous transurethral prostatectomy and 13 had idiopathic detrusor overactivity. There were 20 women and 21 men with a mean age of 73.6 years (range 43 to 82) and a symptom duration of 3.6 +/- 4.5 years. After resiniferatoxin treatment 21 patients had clinical improvement (51.2%) including 5 with neurogenic (50%), 11 with previous transurethral prostatectomy (61.1%) and 5 with idiopathic detrusor overactivity (38.5%). An improvement was found in 11 patients with type I initial response (84.6%), 3 patients with type II response (23%) and 7 patients with type III response (46.7%). The 21 patients with improvement had a significant increase in cystometric capacity (208 +/- 80.7 vs 287.2 +/- 118.6 ml, p = 0.001) and a significant decrease in detrusor pressure (33.6 +/- 11.1 vs 27.4 +/- 11.8 cmH(2)O, p = 0.047), but no significant difference in maximal flow rate and residual urine volume.

CONCLUSIONS

Intravesical resiniferatoxin was effective in treating refractory detrusor overactivity in 51.2% of patients with nonspinal cord lesions. Patients with detrusor overactivity due to previous bladder outlet obstruction benefited the most. Detrusor contractility decreased after resiniferatoxin treatment in the group with improvement but did not influence voiding efficiency. The initial detrusor response to resiniferatoxin treatment might predict the clinical outcome.

Perugia urodynamic method of analysis (PUMA): a new advanced method of urodynamic analysis applied clinically and compared with other advanced methods

AIMS

The aim of this study is to compare PUMA curves with different pathologic conditions causing bladder dysfunction in 158 men and 83 women.

METHODS

PUMA results in terms of bladder outlet obstruction and detrusor contractility were compared in 92 men with benign prostatic hypertrophy (BPH) and p(ves) congruent with p(det) (i.e., p(abd) congruent with 0) with the results of the urodynamics operator's opinion, the provisional International Continence Society method, Abrams and Griffith's diagram, urethral resistence factor (URA), Schäfer's diagram, and Watt factor. PUMA curves correlated reliably with different pathologic conditions such as obstructive BPH, orthotopic bladder, cystocele, the neurological bladder, and bladder diverticulum. Statistical analysis indicated excellent agreement between PUMA and URA; agreement with other methods was good in cases of obstruction and nonobstruction. In doubtful cases, as diagnosed by standard methods, PUMA agreed only with the Abrams and Griffith's diagram. PUMA and Wmax were in good agreement on detrusor con traction force. Agreement between PUMA and Schäfer's diagram was excellent for patients with detrusor hypercontractility and good for patients with detrusor hypocontractility and normocontractility. PUMA is the only method applicable to women. It is easy to perform. When integrated with other diagnostic tests, it provides realistic data for diagnosis, medical or surgical therapy, and outcome.

Voiding urgency and detrusor contractility in women with overactive bladders

AIMS

To check whether the contractility of overactive bladders would be affected by voiding urgency.

METHODS

We urodynamically studied 100 women: 20 normal controls (group 1), 60 patients with idiopathic detrusor overactivity (DO), and 20 with neurogenic DO from intracerebral lesions. The idiopathic DO groups 2A (n = 20), 2B (n = 20), and 3 (n = 20) had moderate, severe, and no voiding urgency, respectively. The neurogenic DO group 4 had severe urgency. The delay time of urgent void at cystometry (2 minutes or more or, respectively, less than 2 minutes) defined moderate or severe urgency. Detrusor contractility was defined by the maximum bladder external voiding power (WF(max)).

RESULTS

WF(max) was higher in the idiopathic DO patients than in the controls, had the highest values in group 2B, and did not differ significantly between groups 1-4 and 2A-3.

CONCLUSIONS

We inferred from our data that idiopathic DO suggests a facilitation of voiding contractions and that such facilitation might be centrally amplified by severe urgency. This amplifying effect would probably be impaired in cases of neurogenic DO from intracerebral lesions.

The management of female voiding dysfunction: Fowler's syndrome -- a contemporary update

PURPOSE OF REVIEW

Several aspects of voiding dysfunction in women remain under investigation, including standardization of the diagnosis and management of bladder outflow obstruction. This article describes a specific cause of urinary retention in young women, associated with a failure of urethral sphincter relaxation, and a treatment option that can restore voiding in this group of patients - sacral nerve electrical stimulation therapy. Recently there have been advances in the stimulator implantation technique, as well as in our appreciation of its mechanism of action.

RECENT FINDINGS

Advances include the use of ancillary investigations such as urethral function tests as well as better understanding of the clinical profile of these patients. Improvements in the surgical technique include better methods of lead fixation and a less invasive surgical approach. Research suggests the action of neuromodulation is on the afferent pathway, though it remains to be shown whether this is at a spinal or supraspinal level. It is likely that sacral nerve stimulation has an indirect modulatory effect on detrusor contractility rather than a direct effect on the sphincter.

SUMMARY

Experience of sacral nerve stimulation has increased over the past few years, and its application is expanding to other clinical domains. This knowledge has helped improve the therapy, which is particularly effective in the treatment of women with urinary retention. Although how it works is still not fully understood, this is something that is being addressed by ongoing research.

Causes for variability in repeated pressure-flow measurements

OBJECTIVES

To study the causes for the variation between measurements, which is considerable, in maximal flow rate (Qmax) and the associated detrusor pressure (PdetQmax). Because of the central role of Qmax and PdetQmax in the diagnosis of bladder outlet obstruction, this is reason for concern.

METHODS

Spectral analysis was carried out on two consecutive urodynamic measurements in 131 patients. The parameters for bladder outlet resistance and bladder contraction strength were determined, and difference plots were made to study the systematic variations. Logistic regression analysis was used to study whether the differences represent true changes of the function of the lower urinary tract.

RESULTS

Signal components in the detrusor pressure and the flow rate signal with frequencies of 1 Hz or greater may be considered noise. Filtering out these frequencies changes the estimates of Qmax and PdetQmax, but not the between-measurement difference in them. Bladder contractility and bladder outlet resistance were systematically lower in the second measurement. Both the systematic and nonsystematic between-measurement variations were statistically significant predictors for postvoid residual urine volume.

CONCLUSIONS

The nonsystematic between-measurement variability in Qmax and PdetQmax apparently reflects true variability in the physiologic state of the bladder outlet. It therefore does not discredit the pressure-flow study as the preferred method in the diagnosis of bladder outlet obstruction. Rather, the pressure-flow study is the only currently available method to study and quantify the apparent within-patient variability in bladder outlet resistance and bladder contractility.

Benign prostatic hyperplasia

In both ageing men and women, there is an increasing incidence of lower urinary tract symptoms (LUTS) which are increasing. These infections have many possible causes, including smooth muscle dysfunction, neurological factors and benign prostatic hyperplasia. Up to 15% to 25% of men aged 50-65 years have LUTS of sufficient severity to interfere with their quality of life. Although benign prostatic hyperplasia is an important cause of these symptoms, and can have serious consequences, clinicians should be aware of these other causes so that the appropriate diagnosis is made before invasive treatments are started. New medical treatments, including alpha-adrenergic blocking agents and 5 alpha-reductase inhibitors mean that many men without complications such as infection, bleeding, or chronic retention, and with mild to moderate symptoms, should be managed in primary care. Combined local protocols between primary and secondary care will help to establish which men with persistent symptoms or complications need referral for a urological opinion to determine the need for further investigation and more invasive forms of management. We review the pathophysiology of the disease, and current approaches to investigation and management of this common problem.

Which stop test is best? Measuring detrusor contractility in older females

PURPOSE

Impaired detrusor contractility has an important role in geriatric voiding dysfunction but there are many competing methods of measurement. We compared the performance of 3 methods of measuring detrusor contraction strength to identify the best one.

MATERIALS AND METHODS

We retrospectively analyzed urodynamics data on 84 females 53 years old or older. All had urge incontinence and were enrolled in a placebo controlled oxybutynin trial. Stop tests (voluntary interruption, mechanical interruption and continuous mechanical occlusion of flow) were performed on each subject.

RESULTS

At baseline the voluntary stop test measured lower mean isovolumetric detrusor pressure +/- SD than the mechanical and continuous methods (31.2 +/- 16.0 versus 47.2 +/- 26.5 and 48.7 +/- 24.4 cm. water, respectively). The latter 2 values also correlated highly (r = 0.87). Followup data on 76 women confirmed these results. Based on baseline and followup values in the 20 women who received placebo the continuous occlusion test showed highest test-retest reliability (r = 0.9, p <0.01), followed by the mechanical (r = 0.69, p = 0.01) and voluntary (r = 0.67, p <0.01) stop tests. Treatment with oxybutynin decreased isovolumetric detrusor pressure in all 3 stop tests by up to 6 cm. water. However, the decrease was statistically significant only for the continuous occlusion test.

CONCLUSIONS

To assess detrusor contraction strength in elderly females with urge incontinence the mechanical stop and continuous occlusion tests are acceptable but the continuous occlusion test has better reliability and better detects slight drug induced changes. Voluntary stop tests greatly underestimate detrusor isovolumetric pressure and should no longer be used.

Effect of botulinum a toxin in the treatment of voiding dysfunction due to detrusor underactivity

OBJECTIVES

To investigate the effects of botulinum A toxin in treating patients with voiding dysfunction due to detrusor underactivity.

METHODS

Twenty patients with chronic urinary retention (n = 13) or severe dysuria (n = 7) received 50 U of botulinum A toxin by urethral injection. The clinical effects, obstructive symptom score, quality-of-life index, and urodynamics were compared at baseline and after treatment.

RESULTS

Of the 4 males and 16 females (age range 14 to 86 years) with voiding dysfunction (cauda equina lesion in 5, dysfunctional voiding in 5, peripheral neuropathy in 6, and detrusor failure of unknown origin in 4), 18 (90%) were treated satisfactorily. Among these patients, the mean quality-of-life score decreased significantly from 5.68 +/- 0.67 to 1.16 +/- 1.61. The median voiding pressure (56.5 +/- 41.2 versus 39.0 +/- 38.4 cm H(2)O) decreased significantly, as did the maximal urethral closure pressure (65.5 +/- 38.1 versus 50 +/- 32.1 cm H(2)O) and residual urine volume (300 +/- 189.1 versus 50 +/- 153.6 mL) at 2 weeks after treatment and remained stationary for 3 months. The subjective maximal effect was achieved within 1 to 2 weeks. In 7 patients, the indwelling catheters were removed, and in 4 patients who performed clean intermittent self-catheterization, the frequency decreased or it was discontinued. The other 7 patients with difficult urination had significant improvement in the obstructive symptom score (18 +/- 3.3 versus 7 +/- 4.5, P = 0.000).

CONCLUSIONS

Botulinum A toxin at a dose of 50 U was effective in reducing urethral sphincter resistance among our patients with detrusor underactivity and difficult urination.

Quality control in urodynamics: a review of urodynamic traces from one centre

OBJECTIVE

To investigate quality control in our unit and to enable other units to compare their results, as experience from central reviews of urodynamic traces for multicentre trials has suggested that poor quality control is common.

PATIENTS AND METHODS

All consecutive male urodynamic tests conducted over 1 year were reviewed. A list of criteria to assess the quality of the records was devised, based upon International Continence Society guidelines on "good urodynamic practice", and on other sources. Eligible traces were analysed for aspects of quality control, e.g. baseline pressures and coughs to test pressure transmission. The data were analysed to establish how often quality criteria were met, and identify areas for improvement.

RESULTS

In 100 eligible traces, the baseline detrusor pressure was 0-10 cmH2O in 86, and - 5 to +10 cmH2O in 94%. Baseline intravesical and abdominal pressure were 30-50 cmH2O in 68% and 73% of cases, respectively. Coughs were present before filling in 94%, during filling in 95%, before voiding in 72% and after voiding in 87% of cases. The cough-test frequency was sufficient in 30% of traces. In 11 the intravesical pressure line fell out during voiding.

CONCLUSION

Most of the traces assessed met the quality criteria defined, but significant defects were not uncommon. Some of the problems identified suggest areas of urodynamic technique which should be studied in more detail. We intend to modify our quality control practices, and hope to show an improvement on re-audit. We hope that other urodynamic departments will be encouraged to review their practice, and we aim to improve our results.

Pre-selection of patients for pressure-flow analysis based on the maximum flow rate

OBJECTIVE

To study the effects of the application of flow rate prescreening to select men for invasive pressure-flow studies, notably the reduction of invasive pressure-flow measurements that can be achieved and the proportion of men in whom, on the basis of the application of a prescreening, an invasive measurement is unjustly not indicated (false negatives). In addition, the variables on which these effects depend are studied.

MATERIALS AND METHODS

Two hundred and sixty-two pressure-flow measurements in 131 patients (2 measurements/patient) and 89 free-flow measurements that preceded the invasive measurements in some patients were studied. A mathematical model was developed based on the outcomes of the invasive measurements. By means of the model the effects of several flow rate prescreening scenarios were estimated. A comparison of the model predicted and actually observed effects of flow rate prescreening was made for those measurements that were preceded by a free-flow rate measurement.

RESULTS

The application of a free-flow rate prescreening may result in a reduction of the number of invasive measurements of 20-30% at a 5% false negative rate. The reduction that may be achieved at an assumed constant false negative rate depends on the distribution of the maximum flow rate in the population and on the definition of bladder outlet obstruction used. When the measurement selection procedure was applied to the free-flow rate measurements that were available in 89 patients, a 21% reduction in invasive measurement indications was found (25% expected). Four patients (4.5%) would have been unjustly excluded from invasive procedures (maximally 5% expected), three of these four patients were borderline obstructed.

CONCLUSION

Considering the bother and risk to the patient and the cost of invasive measurements we think that a 20-30% gain in efficiency at a 5% risk of unjustly declaring a patient unobstructed makes a flow rate prescreening procedure cost effective in the diagnosis of bladder outlet obstruction.

Comparison of parameters to determine the cause of urinary disturbance in men with prostate volume less than 20 milliliters

BACKGROUND

A pressure-flow study, although a slightly invasive procedure, can evaluate bladder outlet obstruction and detrusor contractility. This study was conducted in men with a non-enlarged prostate to determine the cause of urinary disturbance by less invasive examinations that might eventually replace pressure-flow study.

METHODS

Thirty-six men with lower urinary tract symptoms were enrolled. Their prostate volume, estimated by transrectal ultrasonography, was less than 20 mL. All patients were examined using pressure-flow study, free-flowmetry, transrectal ultrasonography, prostate specific antigen and an interview using the International Prostate Symptom Score and Quality of Life Index. With determination of the cause for urinary disturbance, parameters that correlated with outflow obstruction or impaired detrusor contractility were sought.

RESULTS

Twenty-one (60%) of the 36 men were judged as having outflow obstruction, and 16 of these 21 men had normal detrusor function. Impaired detrusor contractility was observed in 17 men. Only three of these 17 men had no outflow obstruction. Four patients had an unstable bladder. All these four had normal detrusor contractility, but had outflow obstruction. Among the parameters examined, only the maximum flow rate in a flow metrogram (Qmax) correlated significantly with the degree of outflow obstruction (P = 0.04). The positive predictive value of Qmax for outflow obstruction was 65% at a flow rate of less than 10 mL/s, and 100% at that of less than 5 mL/s. No parameter correlated with detrusor contractility.

CONCLUSION

The only parameter that was a clear indicator of outflow obstruction was Qmax. Other indicators of detrusor contractility should be sought.

Impaired detrusor contractility: anything new?

Impaired detrusor contractility (IDC) is a poorly defined entity that represents a treatment challenge for the urologist. The etiology of IDC is variable and may include neurologic disorders, inflammatory conditions, and pharmacologic and psychogenic causes. The gold standard for the treatment of IDC is clean intermittent catheterization (CIC). Although well-established as efficacious and safe, CIC may be conceived as a major burden on a patient's quality of life and has been associated with urinary tract infections and urethral and/or bladder injury. Alternative treatment modalities for IDC can be divided into interventions at the nervous system supplying the bladder, the bladder itself, or the bladder outlet. We review and discuss novel and creative treatment options for patients with IDC that have been developed or tested over the past decade.

Comparative study of pressure-flow parameters

Methods for quantification of bladder outlet obstruction (BOO) are still controversial. Parameters such as detrusor opening pressure (p(det.open)), maximum detrusor pressure (p(det.max)), minimum voiding pressure (p(det.min.void)), and detrusor pressure at maximum flow rate (P(det.Qmax)) separate obstructed from nonobstructed patients to some extent, but two nomograms, the Abrams-Griffiths nomogram and the linearized passive urethral resistance relation (LinPURR), are more accepted for this purpose, along with the urethral resistance algorithm. In this retrospective, methodologic study, we evaluated the properties of these parameters with regard to test-retest reproducibility and ability to detect a moderate (pharmacologic) and a pronounced (surgical) relief of bladder outlet obstruction. We studied the pressure-flow charts of 42 patients who underwent 24 weeks of androgen suppressive therapy, 42 corresponding patients who received placebo, and 30 patients who had prostate surgery. The patients performed repeat void pressure-flow examinations before and after treatment or placebo. The various parameters were compared. Among the bladder pressure parameters, P(det.Qmax) seemed to have some advantages, supporting the belief that it is the most relevant detrusor pressure parameter to include in nomograms to quantify BOO. In assessment of a large decrease in urethral resistance, such as after TURp, resistance parameters that are based on maximum flow rate as well as detrusor pressure are preferable.

Good urodynamic practices: uroflowmetry, filling cystometry, and pressure-flow studies

This is the first report of the International Continence Society (ICS) on the development of comprehensive guidelines for Good Urodynamic Practice for the measurement, quality control, and documentation of urodynamic investigations in both clinical and research environments. This report focuses on the most common urodynamics examinations; uroflowmetry, pressure recording during filling cystometry, and combined pressure-flow studies. The basic aspects of good urodynamic practice are discussed and a strategy for urodynamic measurement, equipment set-up and configuration, signal testing, plausibility controls, pattern recognition, and artifact correction are proposed. The problems of data analysis are mentioned only when they are relevant in the judgment of data quality. In general, recommendations are made for one specific technique. This does not imply that this technique is the only one possible. Rather, it means that this technique is well-established, and gives good results when used with the suggested standards of good urodynamic practice.

Non-neurogenic female voiding dysfunction

PURPOSE OF REVIEW

The pathophysiological mechanisms of female voiding phase dysfunction are poorly understood, and there are neither standard definitions nor guidelines for diagnosis and treatment. The aim of this review is to present up-to-date data and controversies associated with non-neurogenic female voiding dysfunction.

RECENT FINDINGS

Conceptually, voiding phase dysfunction may have bladder or urethral causes. Bladder causes include detrusor contraction of inadequate magnitude or duration to effect bladder emptying (detrusor underactivity), or the absence of detrusor contraction (detrusor arreflexia). Urethral causes consist of bladder outlet obstruction as a result of urethral overactivity (functional obstruction), or anatomical (mechanical obstruction) pathologies. The specific prevalence and contribution of each of the above mechanisms is unknown. Furthermore, a correct and timely diagnosis may be difficult, because clinical features are very similar to those of other lower urinary tract symptoms, and diagnostic modalities are often inconclusive or even misleading. A full urodynamic evaluation is essential in making the diagnosis; however, standard urodynamic definitions are still lacking. In the following review, we will present recent findings associated with the prevalence, etiology and diagnosis of each of the different categories of female voiding phase dysfunction, and highlight new advances presented during the past year.

SUMMARY

Further epidemiological and pathophysiological investigations are needed to evaluate the causes and main risk factors of voiding dysfunction in women. A better understanding of the pathophysiological mechanisms associated with this challenging condition may provide the possibility to use appropriate diagnostic and treatment modalities, thus avoiding unnecessary interventions.

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

To diagnose bladder outlet obstruction in male patients with lower urinary tract symptoms (LUTS), it is necessary to measure the bladder pressure via a transurethral (or suprapubic) catheter. This procedure incurs some risk of urinary tract infection and urethral trauma and is sometimes painful to the patient. We developed an external condom catheter to measure non-invasively the bladder pressure and developed a strategy to classify bladder outlet obstruction (BOO) based on this measurement. Seventy-five patients with a wide range of urological diagnoses underwent a pressure-flow study followed by a non-invasive study. We tested five different strategies to classify the patients using the provisional International Continence Society (ICS) method for definition of obstruction as the gold standard. Leakage of the external catheter occurred in eight (40%) of the first 20 tested patients. In the remaining 55 patients, only five (9%) of the measurements failed because of leakage. Of the 75 patients, 56 were successfully tested non-invasively. According to the ICS nomogram, the PFS showed that 22 of these patients were non-obstructed, 12 patients were equivocal, and 22 patients were obstructed. Ten of these 56 patients strained, and we found that the relatively high abdominal pressures in these patients were not reflected in the externally measured bladder pressure. Of the remaining 46 patients, 12 of 13 non-obstructed patients and 30 of 33 combined equivocal and obstructed patients could be correctly classified. We developed a simple, non-invasive classification strategy to identify BOO in those male patients who did not strain during voiding.

Comparison of long-term results of transurethral incision of the prostate with transurethral resection of the prostate, in patients with benign prostatic hypertrophy

One hundred patients with benign prostatic hypertrophy (BPH) were randomized to transurethral incision (TUIP) or transurethral resection of the prostate (TURP). The average prostate weight before operation was not more than 30.0 g. Indications for the operations were based on the disease history, physical examination, digital rectal examination, laboratory values, and pressure-flow examination. All operations were performed with patients under spinal anesthesia. TUIP was performed with a Collins knife, and TURP was performed with a resectoscope. Follow-up was performed 24 months after the operations. After treatment there were statistically significant daytime and nocturnal reduction in voiding frequencies of 2.9 and 1.7, respectively, after TUIP, and 2.0 and 1.5 after TURP. In both groups, there occurred significantly better maximal flow rate from 7.6 mL/s to 16.9 mL/s in group I and from 6.9 mL/s to 17.6 mL/s in group II. The mean values of linearized passive urethral resistance relation in both groups significantly decreased from 3.6 +/- 0.6 to 1.0 +/- 0.5 after TUIP and from 3.9 +/- 04 to 1.4 +/- 0.5 after TURP. The TUIP procedure is effective and safe for patients with a small number of complications.

Development of a low-cost flow meter to grade the maximum flow rate

We developed an inexpensive flow meter to grade the maximum flow rate of individuals at locations other than the clinical setting. This flow meter consists of a funnel connected to a collecting tube with several exit ports. Urine directed into this tube flows through one or more ports and is collected in a measuring cup to measure the voided volume. The number of ports emitting the liquid is a measure for the flow rate. We made four experimental models to test and compare some of the physical properties. One of these models was selected as a prototype and was tested in five healthy volunteers. All volunteers voided repeatedly in a standard rotating disk flow meter and in this prototype to test its accuracy. The response time of the experimental models depended on the outlet resistance of the exit ports and the volume of the collecting tube. In two models, this time was comparable with that of currently used volume-based electronic flow meters (approximately 2 seconds). In healthy volunteers, the maximum flow rates graded with the selected prototype and those measured with the rotating disk flow meter showed good agreement (difference=0.4+/-2.6 mL/s; mean+/-SD). The low-cost flow meter may be used repeatedly to grade the maximum flow rate at private and familiar locations (for example, at home), which may increase the accuracy of evaluating the urinary stream in patients with lower urinary tract symptoms.

Quest for a detrusor overactivity index

PURPOSE

Urge incontinence, which is the predominant type of geriatric incontinence, is generally attributed to detrusor overactivity. However, detrusor overactivity is present in up to half of continent elderly individuals. We postulated that detrusor overactivity associated with urge incontinence would be more severe but there are no established criteria for judging severity. Using urge incontinence frequency as a yardstick and controlling for nonurodynamic contributing factors we sought intrinsic lower urinary tract parameters that reflect detrusor overactivity severity. We postulated that parameters in 1 or more of 5 domains would be important, namely characteristics of uninhibited contraction, bladder capacity, bladder proprioception, detrusor contractility and sphincter adequacy.

MATERIALS AND METHODS

We analyzed data on 79 community dwelling incontinent individuals older than 60 years old. All subjects had urge incontinence on a 4-day voiding record and underwent multichannel videourodynamics. We examined the associations of urge incontinence frequency with the postulated key factors.

RESULTS

Multivariable analysis revealed that 24-hour urine output and functional bladder capacity consistently predicted urge incontinence frequency. Bladder proprioception was significant in some models. Uninhibited contraction pressure was another predictor. Surprisingly higher uninhibited contraction pressure was associated with lower urge incontinence frequency. This negative correlation was more pronounced in a subgroup with a less adequate sphincter but absent in those with good sphincter function, implying that low uninhibited contraction pressure does not necessarily indicate less severe detrusor overactivity but rather reflects sphincter inadequacy in many patients. Age was not independently associated with urge incontinence frequency.

CONCLUSIONS

We identified functional bladder capacity as a measure of detrusor overactivity severity. The measure commonly used, namely uninhibited contraction pressure, is inappropriate because it is severely confounded by sphincter function, especially in older individuals. Furthermore, we confirmed that urine output, and possibly bladder sensation and sphincter strength modify the clinical manifestation of detrusor overactivity.

Videourodynamic and sphincter motor unit potential analyses in Parkinson's disease and multiple system atrophy

OBJECTIVES

Urinary dysfunction is a prominent autonomic feature in Parkinson's disease (PD) and multiple system atrophy (MSA), which is not only troublesome but also a cause of morbidity in these disorders. Recent advances in investigative uroneurology offer a better insight into the underlying pathophysiology and appropriate management for urinary dysfunction.

METHODS

twenty one patients with PD (15 men, six women, mean age 64 (49-76), mean disease duration 4 years (1-8 years), median Hoehn and Yahr grade 3 (1-4), all taking 300 mg/day of levodopa (100-500 mg)) and 15 with MSA (eight men, seven women, mean age 59 (48-72), mean disease duration 3 years (0.5-6 years)) were recruited. Videourodynamic and sphincter motor unit potential analyses in the patients with PD and MSA were carried out, looking for distinguishing hallmarks that might be useful in the differential diagnosis of these two diseases.

RESULTS

Urinary symptoms were found in 72% of patients with PD and in 100% with MSA. Filling phase abnormalities in the videourodynamic study included detrusor hyperreflexia in 81% of patients with PD and 56% with MSA, and uninhibited external sphincter relaxation in 33% of patients with PD and 33% of those with MSA. However, open bladder neck at the start of filling was not seen in patients with PD but was present in 53% of those with MSA, suggestive of internal sphincter denervation. Sphincter motor unit potential analysis showed neurogenic motor unit potentials in 5% of patients with PD and in 93% of those with MSA, suggestive of external sphincter denervation. On voiding, detrusor-external sphincter dyssynergia was not seen in patients with PD but was present in 47% of those with MSA. Pressure-flow analysis showed that the Abrams-Griffiths number, a grading of urethral obstruction (outflow obstruction >40), in PD (40 in women and 43 in men) was larger than that in MSA (12 in women and 28 in men). Weak detrusor in PD (66% of women and 40% of men) was less common than that in MSA (71% of women and 63% of men). Postmicturition residuals >100 ml were absent in patients with PD but were present in 47% of patients with MSA.

CONCLUSION

Patients with PD had less severe urinary dysfunction with little evidence of internal or external sphincter denervation, by contrast with the common findings in MSA. The findings of postmicturition residuals >100 ml, detrusor-external sphincter dyssynergia, open bladder neck at the start of bladder filling, and neurogenic sphincter motor unit potentials are highly suggestive of MSA.

Bladder outlet obstruction in women: prevalence, recognition, and management

Bladder outlet obstruction in women is an infrequently diagnosed urological condition. Its prevalence has been estimated to be between 2.7% and 29%. The large variation in prevalence is likely a result of the lack of standard diagnostic definition for the evaluation of female bladder outlet obstruction. A combination of history taking; physical examination; and diagnostic tests, including simple pressure void studies, radiographic imaging, endoscopic visualization, and multichannel videourodynamics provides a consistent way to accurately recognize and diagnose bladder outlet obstruction. Causes of obstruction are varied and numerous but generally fall within two broad categories: functional and anatomic. Treatment options are tailored to individual causes of obstruction and range from conservative pharmacologic and behavioral options to more-invasive surgical procedures.

Evaluation of female lower urinary tract symptoms: overview and update

Female lower urinary tract symptoms are nonspecific, and a thorough clinical evaluation is required to establish the correct diagnosis. Such evaluation should consist of a structured micturition history or questionnaire, physical examination with full bladder, micturition diary, pad test and urodynamic evaluation. The urodynamic evaluation should consist at least of cystometry, detrusor pressure/uroflow study, simple ('free') uroflowmetry, assessment of the relative contribution of urethral hypermobility and intrinsic sphincter deficiency, and estimation of postvoid residual urine by ultrasound or catheterization. Recent studies regarding the role of pad tests, micturition diaries and urodynamic studies in the evaluation of female voiding dysfunction are presented. Factors that are associated with the use of transurethral catheter during pressure-flow studies and current controversies regarding the diagnosis of female bladder outlet obstruction are reviewed and discussed. Although the urodynamic study is considered to be the best diagnostic tool in assessment of lower urinary tract function, some practitioners believe that urodynamic evaluation is not routinely warranted and prefer to employ a symptom-based empirical management strategy. Lower urinary tract symptoms are nonspecific, however, and should be used mainly to identify what bothers the patient. Urodynamic studies define the underlying pathophysiology. We believe that treatment of the underlying pathophysiology facilitates better treatment of symptoms.