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

Prevention and management of incontinence following radical prostatectomy

Incontinence after radical prostatectomy can have a significant impact on quality of life. Although several risk factors have been identified, the surgical technique and advancing age are important factors associated with postprostatectomy incontinence. Despite advances in technique, incontinence still occurs in a small group of men. Sphincteric dysfunction is the most common cause of postradical prostatectomy incontinence, but bladder dysfunction cannot be discounted. Treatments range from conservative to surgical and should be tailored to the individual based on the degree of bother and patient willingness to accept different therapeutic options.

Urethral resistance factor (URA) versus Schäfer's obstruction grade and Abrams-Griffiths (AG) number in the diagnosis of obstructive benign prostatic hyperplasia

Different methods of analyzing pressure/flow plots to quantify bladder outlet resistance in men with lower urinary tract symptoms (LUTS) due to benign prostatic hyperplasia (BPH) were developed in the past. The aims of this study were to quantify the degree of agreement between the diagnosis of obstruction by the different methods, and to compare the applicability of the different methods in the evaluation of bladder outflow conditions, in a large group of these men. In consecutive men with LUTS basic initial evaluations, recommended diagnostic tests, and urodynamic investigations were performed. From pressure/flow studies, the group-specific resistance factor (URA), Schäfer's obstruction grade, and Abrams-Griffiths (AG) number were estimated. Men with 21 cm H(2)O < or = URA < or = 29 cm H(2)O and men with Schäfer's grade equal 2 were classified as equivocal. In conformity with the provisional ICS definition, men with 20 < or = AG number < or = 40 were classified as equivocal. In 78% of the 565 included men Schäfer's classification agreed with URA classification. In 82% ICS classification agreed with URA classification. Most agreement (94%) existed between Schäfer's classification and ICS classification. All differences were near the points of intersection of the different boundaries, and a decision whether to perform surgery on a patient is not likely to be influenced by this disagreement. Males with relatively low detrusor pressure at maximum flow and relatively low maximum flow had a high prevalence among those in whom URA and Schäfer's classifications and among those in whom URA and ICS classifications differed.

Bladder outlet obstruction nomogram for women with lower urinary tract symptomatology

The aim of our study was to construct a bladder outlet obstruction nomogram for women with lower urinary tract symptoms. A urodynamic database of 600 consecutive women was reviewed. Bladder outlet obstruction, utilizing strict diagnostic criteria, was diagnosed in 50 (8.3%) patients. A comparison of patient characteristics, uroflowmetry, and detrusor pressure-uroflow studies was carried out between the obstructed patients (mean age, 64.4 +/- 17.6 years) and 50 age-matched unobstructed controls (mean age, 64.8 +/- 10.7 years). Maximum flow rates were significantly higher in free uroflow studies (free Qmax) than in pressure-flow studies (Qmax), in both obstructed (9.3 +/- 3.7 versus 5.7 +/- 3.6 mL/s, respectively. P = 2. 6 10(-6)) and unobstructed (25.6 +/- 11.2 versus 11.8 +/- 5.9 mL/s, respectively. P = 8.7 10(-12)) patients. Comparison of detrusor pressure at maximum flow (pdet.Qmax) and maximum detrusor pressure during voiding (pdet.max) values did not reveal significant differences, in both obstructed (39.3 +/- 18.4 versus 49.7 +/- 25.5 cm H(2)O, respectively) and unobstructed (16.5 +/- 8.4 versus 20.6 +/- 9.2 cm H(2)O, respectively) patients. Further statistical analysis was carried out to construct bladder outlet obstruction nomogram. The nomogram classifies any pair of values of free Qmax and pdet.max into one of the following four zones: no obstruction, mild obstruction, moderate obstruction, and severe obstruction. Of the 50 obstructed women, 34 (68%) were classified by the nomogram as mildly, 12 (24%) as moderately, and 4 (8%) as severely obstructed. A positive correlation was found between subjective severity of the symptoms (assessed by the AUA Symptom Index score) and the four nomogram zones. In conclusion, the nomogram makes it possible to differentiate between obstructed and unobstructed women and between various degrees of obstruction. We believe the nomogram may also serve as an instrument to assess treatment outcomes.

Variability of pressure-flow studies in men with lower urinary tract symptoms

The objective of this study was to assess the short-term test-retest variability of pressure-flow studies (PFS) in men with lower urinary tract symptoms (LUTS). By choosing a short interval between two consecutive PFS, but notably not performing two tests within a single session, both tests represent the same routine testing procedure. Eighty-nine patients with LUTS suggestive of bladder outlet obstruction or detrusor underactivity, who received PFS, were asked to undergo a second urodynamic evaluation within 4 weeks after the initial test. At both visits, specialized physicians performed the PFS. Obstruction was quantified using the Abrams-Griffiths number (AG number). Each patient was classified as obstructed, unobstructed, or equivocally obstructed according to the International Continence Society nomogram. As expected, no systematic difference was observed in AG number between the first and the second visit at the group level. There was, however, considerable variation at the individual level. The average within-patient standard deviation was 14 cm H(2)O. This finding shows that if a patient's AG number is 30 at the first visit, his true AG number can be any value between 30 +/- 1.96 * 14 = 3 to 57, owing to random variability alone. The average within-patient standard deviation did not differ significantly between sub-groups of obstruction and other variables such as patient age, symptom score, prostate volume, or residual volume. The variability appeared to increase slightly with an increased interval between visits. Of all patients, 39% changed at least one category of obstruction at the second visit and 3% changed from definitely obstructed to definitely unobstructed or vice versa. We conclude that PFS cannot stand the test of serving as a gold standard to identify bladder outlet obstruction in patients with LUTS.

Pressure flow study data in a group of asymptomatic male control patients 45 years old or older

PURPOSE

The role of pressure flow studies in the routine evaluation of patients with benign prostatic hyperplasia remains a controversial issue in urological practice. There are little data on age matched asymptomatic control groups. We evaluated pressure flow findings in such a group.

MATERIALS AND METHODS

A total of 24 male patients 47 to 80 years old (mean age 62.5) attending a general surgical clinic were recruited for study after ethical committee approval. The volunteers had never sought medical attention for urinary symptoms and did not perceive themselves as having a urological problem. Volunteers were assessed by International Prostate Symptom Score (I-PSS) and Madsen symptom score, clinical examination, free uroflowmetry, post-void residual ultrasound, repeat pressure flow studies and transrectal ultrasonography. Pressure flow tracings were manually analyzed for standard urodynamic values and the degree of bladder outflow obstruction according to recognized International Continence Society, Abrams-Griffith nomogram, linear passive urethral resistance relation and urethral resistance factor classifications.

RESULTS

Median I-PSS was 2.0 (interquartile range 1.2 to 5.7). For I-PSS quality of life the median was 1.0 (interquartile range 0.75 to 2.0). On pressure flow studies 3 patients (13%) had unequivocal obstruction, 7 (29%) were in the equivocal area and 14 (58%) had no obstruction, while 15 (63%) had unstable contractions on medium fill cystometry.

CONCLUSIONS

The data show that a surprising number of apparently normal men are obstructed by commonly used criteria. This finding confirms asymptomatic obstruction, suggesting that obstruction may be less important in the development of symptoms than previously thought. Also, until the natural history of obstruction is more clearly defined surgery in obstructed asymptomatic patients is probably unwise.

Neurogenic failures of the external urethral sphincter closure and relaxation; a videourodynamic study

Urinary urgency and voiding difficulty are common features in neurological diseases, which can be attributed to dysfunction of the urethral sphincter and the detrusor. However, little is known about dynamic sphincter behaviour in neurological diseases. The present study aimed at investigating neurogenic failures of the external urethral sphincter closure and relaxation by videourodynamic study. We recruited 44 neurological patients with urinary urgency and frequency, 27 men and 17 women, mean age 61 years, and 28 of them had voiding difficulty as well. None had abnormal finding of digital examination or ultrasound echography of the pelvic organs. Using triple-lumen 7F catheter under X-ray fluoroscope, we measured detrusor pressure, external urethral sphincter pressure (Pura) and external sphincter EMG in all patients. We also performed pressure-flow study and obtained the Abram-Griffiths (AG) number, a numerical grade of obstruction. During filling 30 had detrusor hyperreflexia. EMG-cystometry showed uninhibited external sphincter relaxation (UESR) in eight patients, seven of whom had detrusor hyperreflexia as well. Patients with UESR showed an abnormal reduction of Pura, mean reduction 64 +/- 27 cmH2O (mean +/- standard deviation). During UESR the Pura and EMG activity fluctuated, and fluoroscopic image showed bladder neck opening in four with extreme urge sensation, including one without detrusor hyperreflexia. During an attempt of voiding three patients with voiding difficulty had detrusor-external sphincter dyssynergia (DESD) with detrusor contraction and eight had unrelaxing external sphincter without detrusor contraction. Fluoroscopic image showed an incomplete or absent urethral opening at the external sphincter. Four of them had severe straining on voiding together with intermittent increment of EMG activity without a normal funneling of the bladder neck. The mean reduction of Pura during voiding was 6.4 +/- 6.7 cmH2O and 5.0 +/- 9.5 cmH2O (in women and men, respectively) with DESD or unrelaxing external sphincter which was less than 39 +/- 25 cmH2O and 53 +/- 47 cmH2O in those without (P < 0.01). The mean AG number was 15 +/- 21 and 51 +/- 19 (for women and men, respectively) with DESD or unrelaxing external sphincter which was larger than 6.2 +/- 34 and 35 +/- 22 in those without (P < 0.05). In conclusion, UESR and DESD/unrelaxing external sphincter could be a factor for urinary urgency and voiding difficulty in neurological patients, evidence of central dysregulation affecting the Onuf's nucleus and its fibres to the external urethral sphincter.

Model-based estimation of male urethral resistance and elasticity using pressure-flow data

To assess urethral resistance and changes in the urethral elasticity during voiding, a lumped parameter model of the urethra was developed. The model uses pressure and flow measurements to estimate time-dependent resistance and elasticity factor. The model includes a resistance that has a function of the cross-section and urethral elasticity. Two resistivity types are compared in the constricted flow-controlling zone of the urethra: Poiseouille resistance and the Bernoulli effect. Using real pressure-flow data sets, the model was used to estimate urethral resistance and changes in urethral elasticity during voiding. Estimation of the elasticity show that in a normal patient relaxation of the urethra is a process that continues until the end of voiding. This has important implications with regard to the present methods that are used in the clinic to assess urethral obstruction or constriction. The resistance as calculated by this model, may be a useful indicator of urethral constriction and obstruction, since it is especially independent of the bladder function. Changes in the urethral elasticity during voiding which are estimated by the model add a new diagnostic parameter to pressure-flow studies.

Tamsulosin in men with confirmed bladder outlet obstruction: a clinical and urodynamic analysis from a single centre in New Zealand

OBJECTIVE

To evaluate the clinical and pressure-flow effects of tamsulosin 0.4 mg once daily in patients with lower urinary tract symptoms (LUTS) caused by benign prostatic obstruction (BPO), as documented by pressure-flow studies performed according to a standardized protocol in one centre.

PATIENTS AND METHODS

A single-centre study was conducted with an open-label design comprising a 2-week, single-blind, placebo run-in period and a 12-week active treatment period with tamsulosin 0.4 mg once daily. Eligible patients were men (aged > or = 45 years) with LUTS (total International Prostate Symptom Score, IPSS, > or = 13) with a free-flow maximum urinary flow rate (Qmax) of > or = 4 mL/s for a voided volume of > or = 120 mL. After the 2-week placebo run-in period, only patients with BPO (i.e. in the obstructed zone of the Abrams-Griffiths, AG, nomogram) received active treatment with tamsulosin. The two primary efficacy variables were the change in detrusor pressure at maximum flow (PdetQmax) and the total IPSS, from baseline to endpoint. A standardized protocol was used for all pressure-flow studies.

RESULTS

In all, 42 patients were enrolled into the 2-week placebo run-in period, after which 30 received active treatment with tamsulosin 0.4 mg once daily. All 12 patients (29%) who discontinued during the placebo run-in period failed to fulfil the pressure-flow entry criterion of confirmed obstruction. The 30 patients who received tamsulosin had a high mean PdetQmax (82.1 cm H2O) and high mean AG number (68.1) at baseline, as would be expected in obstructed patients. Tamsulosin produced a significant reduction in mean PdetQmax (-10.6 cm H2O or -13%; P = 0.005 vs baseline). The mean AG number decreased accordingly (-15.5 points or -23%; P < 0.001 vs baseline). The pressure-flow mean Qmax was increased by 2.5 mL/s (36%) from 7.0 mL/s at baseline (P = 0.002 vs baseline). Urodynamic improvements were accompanied by a good symptomatic response; the mean total IPSS was reduced by 6.7 points from a baseline value of 18.1 (-37%, P < 0.001 vs baseline). At the endpoint, 67% of patients had a clinically significant symptomatic response (defined as a decrease in total IPSS of > or = 25% from baseline). Twenty-six patients (87%) were either slightly improved (13) or were much improved (13) in the opinion of the investigator. Twelve patients with LUTS who were unobstructed after the 2-week placebo run-in (PdetQmax 44.1 cm H2O) received tamsulosin treatment outside of the study protocol. Although these patients had no decrease in mean PdetQmax, the magnitude of the symptomatic response (decrease in total IPSS -6.4 or -34%, P = 0.001) was comparable with that in unobstructed patients; the free-flow Qmax was also significantly improved. Possibly or probably drug-related adverse events were reported in nine patients; one discontinued tamsulosin treatment because of a serious adverse event.

CONCLUSION

Tamsulosin 0.4 mg once daily can produce a significant decrease in detrusor pressure, increase in flow rate and a symptomatic improvement in patients with LUTS and confirmed obstruction. Patients with LUTS who are unobstructed and have a low initial detrusor pressure appear to have no improvement in detrusor pressure, but have similar clinical responses to those in obstructed patients. Pressure-flow studies can be reserved for those patients with LUTS who fail to respond to these agents and in whom further diagnosis and management is warranted.

Reliability of color Doppler ultrasound urodynamics in the evaluation of bladder outlet obstruction

OBJECTIVES

To analyze the intrarater and interrater reliability of a newly developed noninvasive urodynamic technique based on color Doppler ultrasound for the evaluation of bladder outlet obstruction. We previously demonstrated the feasibility of this new technique.

METHODS

Color Doppler ultrasound urodynamic evaluations were performed on 31 men with and without bladder outlet obstruction. An ultrasound image-directed Doppler system with a 3.75-MHz probe operated by a remote control robotic manipulator was used to obtain color scale data using the transperineal approach in men during voiding. We measured the flow velocities in the distal prostatic (V1) and membranous urethra (V2) and used them to obtain the velocity ratio (VR = V1/V2). Combining this information with simultaneous uroflowmetry, the functional cross-sectional area of the distal prostatic urethra (A1) was calculated. These parameters were independently reinterpreted by an inexperienced investigator using the color image data stored in a personal computer. The intrarater and interrater reliability for VR were assessed using a classification based on cutoff values previously shown to indicate the presence or absence of obstruction.

RESULTS

The retest correlation using Spearman's rho for VR in terms of intrarater and interrater reliability was 0.95 and 0.57, respectively; that for A1 was 0.97 and 0.64, respectively. Using a VR of less than 1.1 (to indicate the absence of obstruction) and a VR greater than 1.6 (to indicate the presence of obstruction) for classification, intrarater and interrater agreement occurred in 93.6% to 96.8% and 77.4% to 83. 9% of cases, respectively.

CONCLUSIONS

The color Doppler ultrasound urodynamic technique for noninvasive evaluation of bladder outlet obstruction can be performed with reasonable reliability.

Use of peripheral neuromodulation of the S3 region for treatment of detrusor overactivity: a urodynamic-based study

OBJECTIVES

To determine the efficacy of peripheral neuromodulation of the S3 region in patients with urgency-frequency syndrome due to an overactive bladder.

METHODS

Fifteen patients (11 women and 4 men) with urgency-frequency syndrome, as documented by a voiding chart, were diagnosed with overactive bladder. Pelvic pain was assessed by a visual analogue scale (VAS). Full urodynamic workup was performed before and after 12 peripheral stimulations with a 9-V monopolar generator, the so-called Stoller Afferent Nerve Stimulator (SANS). Follow-up was for a mean (SD) of 10.9 (4 to 15) months.

RESULTS

Reduction in pain was achieved in all patients, with a decrease in VAS from a mean (SD) of 7.6 (5 to 10) to 3.1 (1 to 7) (P = 0.00049). Seven patients (46.7%) had a complete response and were considered cured, 3 (20.0%) showed significant improvement, and 5 (33.3%) were classified as nonresponders. Urodynamic evidence of bladder instability, evident in all patients before treatment, was eliminated in 76.9% of patients. In all patients, mean (SD) total bladder capacity increased significantly from 197 (35 to 349) to 252 (78 to 384) mL (P = 0.00795), mean (SD) volume at first bladder sensation from 95 (16 to 174) to 133 (32 to 214) mL (P = 0.00166), and mean (SD) bladder volume at normal desire to void from 133 (27 to 217) to 188 (47 to 296) mL (P = 0.00232). In the responding group, the mean (SD) total numbers of voids was reduced from 16.1 (9 to 24) times during the day and 4.4 (2 to 6) times during the night to 8.3 (6 to 10) and 1.4 (1 to 2) times (P = 0.002539), respectively. No complications from treatment were observed.

CONCLUSIONS

Peripheral neuromodulation of the S3 region can successfully treat patients with urgency-frequency syndrome due to an overactive bladder.

Clinical significance of detrusor sphincter dyssynergia type in patients with post-traumatic spinal cord injury

OBJECTIVES

To investigate the significance of categorizing detrusor sphincter dyssynergia (DSD) by type in patients with chronic spinal cord injury.

METHODS

A retrospective review of the charts, video-urodynamic studies, and upper tract radiographic studies of 269 patients with post-traumatic, suprasacral spinal cord injuries was performed. The patients were categorized according to the DSD type (intermittent or continuous), level and completeness of injury, intravesical pressure at leak, upper tract complications, and interval since injury.

RESULTS

Of the 269 patients, 20 (7.4%), 216 (80.3%), and 33 (12.3%) had no DSD, intermittent DSD, and continuous DSD, respectively. No significant association between the specific level of injury and the DSD type was found (P = 0.71). The presence of DSD was associated with complete injuries, elevated intravesical pressures, and upper tract complications (P <0.01); these associations were more prominent with continuous DSD than with intermittent DSD. The proportion of patients with no DSD, intermittent DSD, and continuous DSD was unchanged during the chronic follow-up period.

CONCLUSIONS

The clinical significance of DSD type is not crucial, since patients with both intermittent and continuous DSD require urodynamic surveillance and expedient treatment to minimize urologic complications. However, the presence of continuous DSD is one of several factors that may require earlier urodynamic follow-up.

Noninvasive urodynamic evaluation of bladder outlet obstruction using Doppler ultrasonography

OBJECTIVES

Previously we had developed a new method of noninvasive urodynamics using color Doppler ultrasound. Using this technique, we attempted to identify parameters that would diagnose bladder outlet obstruction (BOO).

METHODS

Twenty-two men who underwent pressure-flow urodynamic studies were included. Color scale transperineal ultrasound and uroflowmetry data were analyzed by custom-made software. The maximum flow velocities in the entire prostatic urethra (V(0)), in the distal prostatic urethra just proximal to the external urethral sphincter (V(1)), and in the membranous urethra (V(2)) were obtained. Corresponding functional cross-sectional areas of the urethra at these three sites (A(0), A(1), and A(2)) were calculated as Qmax/V. The velocity ratio (VR), which was equal to V(1)/V(2), was also calculated as a parameter. All these parameters obtained by the velocity-flow urodynamics were compared with the Abrams-Griffiths number (AG).

RESULTS

From the x-y plots obtained, VR correlated best with AG, with Spearman's rho of 0. 728. A(0) and A(1) had rho values of -0.461 and -0.708 against AG, respectively. All men with VR exceeding 1.6 had obstruction, whereas those with VR less than 1.1 did not.

CONCLUSIONS

The VR was found to be the best parameter for diagnosing BOO. When prostatic urethral obstruction was present, the velocity in the prostatic urethra would be high but the velocity slows down to 62.5% or greater immediately below the sphincter. We believe that noninvasive pressure-flow-like urodynamic evaluation based on Doppler ultrasound has clear potential for diagnosing BOO.

Sequential changes in voiding dynamics related to the development of detrusor instability in women with stress urinary incontinence

We evaluated 31 women who had undergone a conservative treatment regimen for stress urinary incontinence and who, during the treatment period, were assessed twice urodynamically (by cystometry and pressure/flow study) at an interval of months between the two examinations. Seventeen (Group 1) had stable bladders at time 1 and detrusor instability (DI) after a mean of 12 months (time 2). Fourteen (Group 2) had stable bladders both at time 1 and after a mean of 15 months. Of the urodynamic parameters evaluated, the opening detrusor pressure (pdet.op) reflected the height of the bladder neck pressure rise that normally occurs during the opening phase of micturition and that is overcome by the detrusor contraction pressure at the onset of flow. At the second testing, Group 1 patients showed greater detrusor strength. They also showed a more elevated pdet.op (= a more elevated bladder neck pressure rise during the onset of voiding detrusor contraction), which may have been necessary to ensure an enhanced bladder contractility level. Indeed, a higher rise in pressure, hence in muscular tension, at the bladder neck region should obviously lead to increased afferent signals from tension receptors, and positive feedback to the detrusor of such increased signals may yield more intense neural stimulation. This would amplify the facilitating effect on bladder contractility of a possible DI-related decrease in electrical resistance between the detrusor smooth muscle cells.

Different voiding dynamics in stable and unstable bladders with and without outlet obstruction

Of 120 men with benign prostatic enlargement who were evaluated urodynamically, 60 had stable bladders, with (n=30) and without (n=30) outlet obstruction (OO), whereas 60, both obstructed (n=30) and unobstructed (n=30), had detrusor instability (DI). The unstable bladders, wither in the absence or presence of OO, always showed a greater mechanical capability. In particular, compared to the stable bladders, the unstable ones not only had greater strength, but also showed a higher maximum shortening velocity (as well as a shorter opening time and not significantly higher internal work). In the obstructed unstable series, compared to the obstructed stable one, such findings paralleled a more severely increased urethral impedance, which suggests that a functional "compensatory" response to a greater OO was facilitated. All such data were hypothesized to result from microstructural changes yielding an easier electrical coupling between the detrusor smooth muscle cells and hence both a state of DI and better synchronized (thus, stronger and faster) micturition contractions. At least, the latter would be the case should there be no heavy bladder collagenosis upsetting the spread of the depolarization wave.

Low reproducibility of maximum urinary flow rate determined by portable flowmetry

To evaluate the reproducibility in maximum urinary flow rate (Qmax) in men with lower urinary tract symptoms (LUTSs) and to determine the number of flows needed to obtain a specified reliability in mean Qmax, 212 patients with LUTSs (mean age, 62 years) referred to the University Hospital Nijmegen, with various degrees of obstruction on pressure-flow studies, used a portable home-based uroflowmeter with 12 disposable beakers. Voided volume and maximum flow rate were recorded continuously during micturition. Flows with voided volumes of at least 100 ml and without possible artifacts were included. All analyses were repeated while excluding flows with voided volumes <150 ml. A coefficient of variation (CV) was calculated for each patient. The CV represents the standard deviation relative to the mean. All individual CVs were subsequently pooled into a population mean CV. This parameter was used to estimate the number of flows required to obtain a mean Qmax with specified reliability for an individual patient. All analyses were repeated, while successively excluding the first, the first two, and the first three flows, to assess a possible learning curve. A total of 1,854 flows was available for analyses, yielding an average of nine flows per patient. Mean Qmax was 13.2 ml/sec; the mean CV was 24%. To allow, for instance, a 10% deviation from the true mean Qmax (e.g., 15 ml/s +/- 1.5 ml/s), approximately 25 flows are necessary. The actual number of flows needed is in fact even higher due to the presence of small and artifactual flows. Using a 150 ml volume cutoff point, somewhat fewer flows are required, but the total number of flows needed (that is, valid, small, and artifactual flows) increases. There was no evidence of a learning curve. The boundaries of a confidence interval around a single Qmax measurement that is likely to contain the true mean Qmax, lie approximately 50% below or above that single Qmax measurement. To reduce this proportion down to 10%, approximately 25 flows are needed. Thus, to obtain reliable mean Qmax values, considerably more flows are required than are normally performed in urologic practice.

Bladder outlet obstruction in women: definition and characteristics

The prevalence of bladder outlet obstruction in women is unknown and most probably has been underestimated. Moreover, there are no standard definitions for the diagnosis of bladder outlet obstruction in women. Our study was conducted to define as well as to examine the clinical and urodynamic characteristics of bladder outlet obstruction among women referred for evaluation of voiding symptoms. Bladder outlet obstruction was defined as a persistent, low, maximum "free" flow rate of <12 mL/s in repeated non-invasive uroflow studies, combined with high detrusor pressure at a maximum flow (p(det.Q)(max) >20 cm H(2)O) during detrusor pressure-uroflow studies. A urodynamic database of 587 consecutive women identified 38 (6.5%) women with bladder outlet obstruction. The mean age of the patients was 63.9 +/- 17.5 years. The mean maximum "free" flow, voided volume, and residual urinary volume were 9.4 +/-3.9 mL/s, 144. 9 +/- 72.7 mL, and 86.1 +/- 98.8 mL, respectively. The mean p(det. Q)(max) was 37.2 +/- 19.2 cm H(2)O. Previous anti-incontinence surgery and severe genital prolapse were the most common etiologies, accounting for half of the cases. Other, less common, etiologies included urethral stricture (13%), primary bladder neck obstruction (8%), learned voiding dysfunction (5%), and detrusor external sphincter dyssynergia (5%). Symptomatology was defined as mixed obstructive and irritative in 63% of the patients, isolated irritative in 29%, and isolated obstructive in other 8%. In conclusion, bladder outlet obstruction in women appears to be more common than was previously recognized, occurring in 6.5% of our patients. Micturition symptoms relevant to bladder outlet obstruction are non-specific, and a full urodynamic evaluation is essential in making the correct diagnosis and formulating a treatment plan.

Intra- and inter-investigator variation in the analysis of pressure-flow studies in men with lower urinary tract symptoms

The objective of this study was to assess the intra- and inter-investigator variation in the analysis of pressure-flow studies that were performed in men with lower urinary tract symptoms. Two hospitals were involved in this study. In each hospital 100 PFS were selected. Photocopies of printouts of all PFS were analyzed manually by six experienced investigators, including determination of P(detQmax) and Q(max). Afterward, all 200 PFS were analyzed again in a different order. For each P(detQmax) and accompanying Q(max) the AG-number was calculated. With these AG numbers, the intra-investigator SD, the inter-investigator SD and the intra- and inter-investigator SD combined were calculated. The intra- and inter-investigator SD combined was 10.7. This implies that if one investigator analyzes a PFS once and determines an AG number of 40, another investigator may determine an AG number between 40 +/- 2. 77*10.7 = 10-70, using a 95% confidence interval. The inter-investigator SD was 10.0 and the intra-investigator SD was 3.7. The reproducibility of the manual analysis of urodynamic studies is moderate owing to a considerable intra- and inter- investigator variation. This is mostly caused by the substantial intra-investigator variation.

Pressure-flow study as an evaluating method of neurogenic urethral relaxation failure

Voiding difficulty is a common feature in neurological diseases, which can be attributed to dysfunction of the urethral sphincter and the detrusor. Electromyography (EMG)-cystometry can reveal the presence of detrusor-external sphincter dyssynergia (DESD), however, internal sphincter function on voiding is not easily evaluated. Pressure-flow study is widely used to diagnose benign outlet obstruction due to prostatic hypertrophy. We applied pressure-flow study in neurological patients in order to evaluate neurogenic urethral relaxation failure. We recruited 71 patients with neurological diseases. All were men under 60 years, with mean age of 44 years, ranging from 18 to 59 years. None had abnormal finding of digital examination or ultrasound echography of the prostate. Standard cystometry showed detrusor hyperreflexia in 33 patients and residual urine was noted in 36. DESD was noted in seven of 43 patients. Pressure-flow relation curve and a detrusor pressure (P(det)) at the point of maximum flow rate (Q(max)) (i.e., P(det)Q(max)) were obtained by urodynamic computers. The Abram-Griffiths (AG) number (P(det)Q(max)-2Q(max)), showing outlet obstruction particularly over 40, was also obtained. The points of P(det)Q(max) of the patients fell into three categories of the AG nomogram, showing obstruction in 19.7%, equivocal in 52.1% and unobstructed in 28.2%. Patients with DESD had AG number over 40 more commonly (57.1%) than those without DESD (8.4%) (p<0.05). The mean AG number was 46.4 in patients with DESD, which was larger than 17.1 in patients without DESD (p<0.01). Patients with detrusor hyperreflexia had AG number over 40 more commonly (42.4%) than those with normal cystometric curve (0%) (p<0.01). The mean AG number was 30.6 in patients with detrusor hyperreflexia, which was larger than 13.6 in patients with normal cystometric curve (p<0.01). The results showed that 19.7% of patients with neurological diseases had obstructive pattern (high pressure voiding), evidence of urethral relaxation failure with relatively preserved detrusor contraction. DESD is a factor contributing to the urethral relaxation failure of the patients. The results also indicated a relationship between detrusor hyperreflexia and obstructed pattern, probably reflecting co-occurrence of detrusor hyperreflexia with DESD or detrusor-internal sphincter dyssynergia.

Mitochondrial DNA deletion of the human detrusor after partial bladder outlet obstruction-correlation with urodynamic analysis

OBJECTIVES

To investigate mitochondrial DNA (mtDNA) mutations in human detrusor after partial bladder outlet obstruction (BOO) and correlate the findings with the results of urodynamic studies.

METHODS

Sixty-two male patients with and without BOO were recruited and assessed by the International Prostate Symptom Score, a quality-of-life assessment index, and sonography. The severity of partial BOO was determined by pressure-flow study with an International Continence Society (ICS) nomogram. Random detrusor biopsies obtained cystoscopically were analyzed by polymerase chain reaction (PCR) techniques to detect possible mtDNA deletions. Primer-shift PCR and DNA sequencing were then performed to characterize specific mtDNA deletions. A semiquantitative PCR method was used to determine the proportion of the deleted mtDNA in detrusor. Finally, the mtDNA deletion and the urodynamic results were compared statistically.

RESULTS

A 4977-bp mtDNA deletion was identified in the human detrusor. Its incidence and proportion were found to increase after partial BOO (P = 0.005 and 0.012, respectively). The incidence of the mtDNA deletion was 4.2% (1 of 24) in the unobstructed group, 27.8% (5 of 18) in the equivocal group, and 40% (8 of 20) in the obstructed group. The mean proportion of the 4977-bp deleted mtDNA was 23.7 and 12.7 times higher in the obstructed and equivocal groups, respectively, compared with that of the unobstructed group.

CONCLUSIONS

We found mtDNA with the 4977-bp deletion in human detrusor and an increase of this deletion after partial BOO. This molecular change might account for the previous observations of mitochondrial functional impairment and voiding dysfunction after partial BOO.

Association of level of injury and bladder behavior in patients with post-traumatic spinal cord injury

OBJECTIVES

The expected urodynamic findings of patients with suprasacral and sacral spinal cord injury have previously been reported. However, the associations between the radiographically determined level or levels of injury and urodynamic findings are ill defined. This study investigated these relationships, specifically the bladder behavior of patients with post-traumatic spinal cord injury with combined suprasacral and sacral injuries.

METHODS

A retrospective review of the patient records, spinal imaging studies, and video-urodynamic studies of 316 patients with post-traumatic spinal cord injury was performed. Of these patients, 243 had complete spinal computed tomography or magnetic resonance imaging studies and constitute the study population. Patients were categorized by the radiographically determined level or levels of injury, clinical neurologic level and completeness of injury, and urodynamic findings.

RESULTS

Of the 196 patients with suprasacral injuries, 186 (94.9%) demonstrated hyperreflexia and/or detrusor sphincter dyssynergia, 82 (41.8%) had low bladder compliance (less than 12.5 mL/cm H(2)O), and 79 (40.3%) had high detrusor leak point pressures (greater than 40 cm H(2)O). Of the 14 patients with sacral injuries, 12 (85.7%) manifested areflexia, 11 (78.6%) had low compliance, and 12 (85.7%) had high leak point pressures. Of the 33 patients with combined suprasacral and sacral injuries, urodynamic studies showed 23 with hyperreflexia and/or detrusor sphincter dyssynergia (67.7%), 9 with areflexia (27.3%), 19 (57.6%) with low compliance, and 20 (60.6%) with high leak point pressures.

CONCLUSIONS

In patients with a single level of spinal cord injury, this study revealed a significant association between the level of injury and the type of voiding dysfunction. Patients with combined suprasacral and sacral injuries, as identified with precise spinal imaging techniques, had relatively unpredictable urodynamic findings. Management of the urinary tract in patients with spinal cord injury must be based on urodynamic findings rather than inferences from the neurologic evaluation.

Identifying patients who require urodynamic testing before surgery for stress incontinence based on questionnaire information and surgical history

OBJECTIVES

To determine whether knowledge about previous surgical history for incontinence and responses to a validated lower urinary tract symptom questionnaire for women could identify those who should undergo urodynamic testing before surgery for stress urinary incontinence (SUI).

METHODS

A retrospective analysis of all women who completed the Urogenital Distress Inventory-6 questionnaire (UDI-6) and then underwent complete urodynamic studies was conducted. The critical urodynamic diagnoses to determine before anti-incontinence surgery were defined as coexisting SUI and detrusor instability (DI), Valsalva leak point pressure less than 60 cm H(2)O, and DI alone in women suspected clinically of having SUI. Models were established for deciding who should undergo urodynamic studies on the basis of questionnaire responses and information about previous surgical history. Cost savings and the ability of the various models to identify patients with critical urodynamic diagnoses were calculated.

RESULTS

A total of 174 women completed the UDI-6 and underwent urodynamics studies. Sixty-two had SUI (36%), 54 had DI (31%), 18 had both SUI and DI (10%), and 19 women suspected of having SUI were found instead to have DI (11%). Among women with SUI, 39 had a Valsalva leak point pressure less than 60 cm H(2)O (63%). No group of question responses or combination of question responses and presence of previous incontinence surgery was able to identify all three critical urodynamic diagnoses with statistical significance. Still, the combination of a response of "2" or "3" to question 3 on the UDI-6 and a positive history of previous surgery would have identified 91% of the critical diagnoses, and a substantial cost savings would have been realized.

CONCLUSIONS

Using the UDI-6 and information obtained from the patient's history to determine who should undergo urodynamic testing before surgery for SUI can result in substantial cost savings without sacrificing patient care.

Interstitial laser coagulation in patients with lower urinary tract symptoms from benign prostatic obstruction: treatment under sedoanalgesia with pressure-flow evaluation

OBJECTIVES

To evaluate the effects on lower urinary tract symptoms and pressure-flow variables after interstitial laser coagulation (ILC) of the prostate using the Indigo diode laser system (Indigo, Palo Alto, USA).

PATIENTS AND METHODS

Forty-nine men (median age 68 years, range 52-80) were assessed using symptom scores and voiding variables before and at 3 and 12 months after ILC. A subset of 26 men (median age 68 years, range 63-72) underwent pressure-flow measurements before and at 6 months after ILC. All treatments were performed in the outpatient department using sedoanalgesia.

RESULTS

The International Prostate Symptom Score decreased from 22 to 11 at 12 months after ILC. The peak urinary flow (Qmax ) was 8.6 mL/s at baseline and increased to 9.9 mL/s at 12 months. Residual urine volumes were unchanged. The median duration of urinary retention after ILC was 3 days. From pressure-flow recordings, 17 patients were categorized as obstructed and seven as equivocally obstructed before ILC (using the International Continence Society definition). Their Qmax increased from 7.7 to 9.0 mL/s after 6 months, the detrusor pressure at Qmax decreased from 68 to 51 cmH2O and the Abrams-Griffiths number decreased from 54 to 29 (P<0.01). Patients with moderate to equivocal obstruction had a greater relief of symptoms than those who were clearly obstructed. Patients with prostate volumes of >40 mL had a greater decrease in the Abrams-Griffiths number than had patients with smaller prostates. Postoperative perineal pain was reported by 72% of patients; the pain subsided after 1-2 weeks. The re-treatment rate was 15% within the first year.

CONCLUSION

Treatment with ILC produced substantial effects on symptoms and moderate to small changes in urodynamic variables. Patients with moderate or equivocal bladder outlet obstruction or large prostates seem to be the best candidates for this treatment. However, treatment was followed by perineal pain for 1-2 weeks in most cases. A long-term follow-up is necessary to determine the role of ILC.

Non-invasive measurement of bladder pressure using an external catheter

Previous studies showed that, on the basis of a combination of maximum flow rate and isovolumetric bladder pressure, objectively diagnosing infravesical obstruction is possible. In this study, we validated a newly developed external catheter to measure non-invasively this pressure, which avoids the risk of damaging or infecting the urethral and bladder wall as occurs with invasive urodynamics. To evaluate the external catheter, we simultaneously recorded the internal bladder pressure signal (measured invasively) and the external pressure signal (measured non-invasively) in 40 non-obstructed and obstructed patients. Additionally, we tested whether the external pressure depended on bladder volume in five healthy volunteers. The simultaneously measured internal bladder pressure and external pressure showed good agreement in the non-obstructed patients. There was less agreement in the obstructed group. Nevertheless, the external pressure in these patients was significantly higher than in the non-obstructed patients. The maximum external pressure depended significantly on the bladder volume in all volunteers. We concluded that isovolumetric bladder pressure can be measured non-invasively with the external catheter. In non-obstructed patients, this pressure accurately represents the internal bladder pressure. We think that it is possible to distinguish between obstructed patients and patients with a weak detrusor by combining the non-invasively measured isovolumetric bladder pressure with a separately measured maximum flow rate. Neurourol. Urodynam. 18:455-475, 1999.

Predictability of urodynamic findings based on the Urogenital Distress Inventory-6 questionnaire

OBJECTIVES

The Urogenital Distress Inventory (UDI-6) is a validated 6-item questionnaire that assesses lower urinary tract symptoms, including incontinence, in women. Similar indexes developed in men to evaluate symptoms of benign prostatic hyperplasia have failed to show a relationship with urodynamic (UD) parameters indicating bladder outlet obstruction (BOO). In this study, we sought to determine whether UDI-6 responses could predict information obtained during UD evaluations.

METHODS

All women referred to our clinic with lower urinary tract complaints who completed a UDI-6 questionnaire and subsequently underwent UD evaluation were included (n = 128). UD findings used for analysis included Valsalva leak point pressure (VLPP), maximum flow rate (Qmax), and detrusor pressure at Qmax (PdetQmax). BOO was defined as Qmax of 1 5 mL/s or less and PdetQmax of greater than 20 cm H2O; detrusor overactivity (DO) was defined as any rise in detrusor pressure associated with urge during filling.

RESULTS

The most common chief complaints were incontinence (mixed, 26.6%; stress, 20.3%; and urge, 13.3%), urgency/frequency (14.1%), and symptomatic prolapse (10.1%). There was a moderate correlation between a positive response to question 3 (stress urinary incontinence [SUI]) and leakage with strain or cough during UD evaluation (correlation coefficient = 0.51). In fact, most patients answering that SUI was moderately or greatly bothersome were found to have stress-induced leakage during the UD evaluation (82%), which differed significantly from those who reported no bother (Fisher's exact test, P = 0.0006). Severity of leakage assessed by VLPP, however, did not correlate with the severity assessed by any question. With regard to BOO in women, most patients who answered that incomplete emptying was their most bothersome symptom had BOO (61%), and most women with a different main complaint were unobstructed (73%, P <0.002). Finally, 30 of 36 women who answered that leakage related to urgency was moderately or greatly bothersome were found to have DO, which was significantly different than the incidence of DO in women who did not report this complaint (correlation coefficient = 0.38, P <0.001).

CONCLUSIONS

Unlike similar indexes used to assess lower urinary tract symptoms in men, specific items from the UDI-6 may provide predictive information regarding UD findings in women, particularly with regard to SUI, BOO, and DO. However, if VLPP is considered vital to planning treatment, UD studies will still be required, since no question could estimate the severity of incontinence as determined by serial VLPP measurement.

Prevalence and characteristics of voiding difficulties in women: are subjective symptoms substantiated by objective urodynamic data?

OBJECTIVES

To examine the prevalence and characteristics of voiding difficulties in women.

METHODS

Two hundred six consecutive female patients who attended a urogynecology clinic were recruited. Patients were interviewed regarding the presence and severity of symptoms that would suggest voiding difficulties (ie, hesitancy, straining to void, weak or prolonged stream, intermittent stream, double voiding, incomplete emptying, reduction, and positional changes to start or complete voiding). Urodynamic evidence of voiding difficulty was considered as a peak flow rate less than 12 mL/s (voided volume greater than 100 mL), or residual urine volume greater than 150 mL, on two or more readings. Residual urinary volume, flow patterns, and pressure-flow parameters were analyzed and compared between symptomatic and asymptomatic patients who had urodynamic parameters of voiding difficulties.

RESULTS

One hundred twenty-seven (61.7%) women reported having voiding difficulty symptoms; 79 others (38.3%) were free of such symptoms. Urodynamic diagnosis of voiding difficulty was made in 40 women (19.4% of the study population): 27 in the symptomatic group and 13 in the asymptomatic group (21.2% and 16.5%, respectively). Only 1 patient had voiding difficulty due to bladder outlet obstruction. All other cases of low flow rate were due to impaired detrusor contractility.

CONCLUSIONS

Objective evidence of voiding difficulty may be found in both symptomatic and asymptomatic patients and is usually due to impaired detrusor contractility. The clinical significance of the abnormal flow parameters in asymptomatic patients is unclear.

Relation between urethral elasticity and bladder outlet obstruction and histologic composition of the prostate in patients with benign prostatic hyperplasia

OBJECTIVES

In benign prostatic hyperplasia (BPH), bladder outlet obstruction is caused by mechanical blockage resulting from an enlarged prostate, and by the increased tone of prostatic smooth muscle. In patients with obstructive BPH, the prostatic urethra urodynamically corresponds to the flow-controlling zone (FCZ). We sought to investigate the relation between the obstruction and elastic properties of the FCZ and the histologic composition of the prostate in symptomatic patients with BPH.

METHODS

The grade of infravesical obstruction was classified according to preoperative pressure-flow data from 30 men with symptomatic BPH, and the elastic properties of the FCZ were evaluated as the mean elastance, which was calculated using the three-parameter model. The area densities of smooth muscle, fibrous tissue, epithelium, and lumen were determined by quantitative morphometry, using BPH tissue obtained by transurethral resection.

RESULTS

The area density of smooth muscle had a negative correlation with mean elastance (p = -0.50, P <0.01), the linear passive urethral resistance relation (p = -0.43, P <0.05), and the group-specific urethral resistance factor (p = -0.39, P <0.05). No other histologic element was correlated with these variables.

CONCLUSIONS

Our results suggest that urethral elasticity and bladder outlet obstruction grade are influenced by the relative content of smooth muscle within the prostate in patients with BPH.

The use of voiding studies (flowmetry and urodynamics) in the assessment and follow-up of patients

The role of urinary flow measurement and pressure-flow studies in the diagnostic work-up of men presenting with lower urinary tract symptoms suggestive of benign prostatic obstruction is still an unresolved issue. In this paper, evidence from the peer-reviewed literature of the last 12 months is critically reviewed in the light of the recent recommendations of the 4th International Consultation on benign prostatic hyperplasia.

Diagnostic research in benign prostatic hyperplasia--from sensitivity to neural networks

Establishing the diagnosis in patients with lower urinary tract symptoms is complicated. Several tests have been developed, but the importance of each of these tests in the diagnostic process is not well understood. This paper describes the methods used to evaluate diagnostic tests, ranging from traditional sensitivity and specificity to more sophisticated techniques such as logistic regression and neural networks.

Comparison of three methods of quantifying urethral resistance in men

OBJECTIVES

To determine how well three methods of quantifying urethral resistance from pressure-flow plots compared in men.

METHODS

The pressure-flow plots of 312 men who attended a Continence Clinic for evaluation of lower urinary tract symptoms were analyzed. The Abrams-Griffiths number (AG), detrusor-adjusted mean PURR [passive urethral resistance relation] factor (DAMPF), and group-specific urethral resistance factor (URA) were obtained for each plot. The correlation coefficients and simple regression equations were computed for AG versus DAMPF and AG versus URA. Using the provisional International Continence Society method for definition of obstruction to categorize the AG values as obstructed, equivocal, or unobstructed, we obtained the corresponding DAMPF and URA values for our study population.

RESULTS

The Pearson correlation coefficient, r, for AG versus DAMPF and AG versus URA was 0.941 and 0.889, respectively. The corresponding regression equations obtained were AG = - 32.6 + (DAMPF)1.27 (95% confidence interval [CI] 1.22 to 1.32) and AG = - 16.4 + (URA) 1.67 (95% CI 1.58 to 1.77). The 5th to 95th percentiles of the DAMPF and URA for men who were obstructed (AG number more than 40) were 56 to 92 and 28 to 71, those for men who were equivocal (AG 20 to 40) were 35 to 62 and 17 to 38, and those for men who were unobstructed (AG less than 20) were 12 to 44 and 5 to 24, respectively.

CONCLUSIONS

The DAMPF and URA were highly correlated to the AG in a linear fashion. Although these parameters were developed differently, they appeared to compare well. When using the DAMPF or URA to quantify urethral resistance, it was possible to estimate the corresponding AG value with reasonable confidence.