Pressure-flow studies of micturition

Long-term outcomes of bipolar transurethral enucleation and resection of the prostate on patients with benign prostatic obstruction: a 10-year follow-up

OBJECTIVE

We aimed to explore the long-term outcomes of bipolar transurethral enucleation and resection of the prostate (B-TUERP) in patients with benign prostatic hyperplasia (BPH).

METHODS

A total of 1195 patients with BPH who underwent B-TUERP from July 2006 to June 2010 were enrolled in this retrospective study. Preoperative data, particularly urodynamic study (UDS) parameters, were collected by questionnaire and examination. Postoperative follow-up was performed at 3, 6, 12, 36, 60 and 120 months, respectively. Demographic, perioperative and functional data were analysed. International Prostate Symptom Score, quality of life and overactive bladder syndrome score (OABSS) were used to assess the functional scores. Predictors of postoperative urgency incontinence were identified by univariate analysis.

RESULTS

Long-term outcomes of functional score were significantly better than the preoperative values. All UDS variables, including maximum urinary flow rate, postvoid residual urine volume, compliance, maximum cystometric capacity (MCC), bladder outlet obstruction index, prostatic urethral pressure and detrusor pressure at maximum urinary flow rate, were all significantly improved. No one required reoperation due to recurrent BPH. The postoperative rate of transient urinary incontinence was 31.7%, while the long-term incontinence rate was 0%. Retrograde ejaculation occurred in 44.3% patients who remained sexually active after operation. Patients who had transient urge incontinence were older with preoperative higher OABSS, prostate-specific antigen (PSA) and detrusor overactivity rate and lower MCC.

CONCLUSION

B-TUERP is a safe, successful and highly effective treatment for BPH at 10-year follow-up. Increased age, OABSS, PSA level and detrusor overactivity rate are potential predictors for urge incontinence after B-TUERP.

How correlated is BOO with different objective parameters commonly used in evaluation of BPH: a prospective study

OBJECTIVES

The use of non-intubated uroflowmetry, PVR, prostate volume, and I-PSS are the most commonly used tools for the evaluation of patients with BPH. In this prospective study, we elucidated the correlation between BOO as rated by pressure-flow study in men with LUTS attributed to BPH and those parameters.

METHODS

Over a period of 2 years 460 men above the age of 45 years old (mean age 60.46 ± 9.4) were prospectively included in this study. Symptoms were evaluated using the International Prostate Symptom Score, and digital rectal examination, prostate-specific antigen, and transrectal ultrasound were done. The urodynamic evaluation included uroflowmetry, filling cystometry, and voiding cystometry with the plotting of pressure-flow study according to Lin-PURR (Schäfer's nomogram). The correlation coefficient was calculated between these variables.

RESULTS

The correlation of other objective parameters with total score was not much better. The Spearman's correlation coefficient were - 0.09, 0.07 and - 0.1 for prostate weight, post voiding residual urine and maximum free flow rate respectively. Correlations between Schäfer's grade and Q_max, PVR and prostate volume were found to be weak to fair correlation (r values were - 0.4, 0.18, and 0.39 respectively).

CONCLUSION

Objective non-invasive parameters most commonly used in the evaluation of men with LUTS attributed to BPH have limited correlation with obstruction, as diagnosed by pressure flow nomogram.

The Use of Urodynamics Assessment Before the Surgical Treatment of BPH

Lower urinary tract symptoms (LUTS) are a common problem in men especially with aging. The International Continence Society (ICS) revealed an overall prevalence of LUTS of about two-thirds of men age 40 years and above. The treatment approach depends on accurate determination of the underlying etiology. LUTS is not unique to benign prostate enlargement (BPE) and can be secondary to other causes. In the era where quality of care is important, accurate diagnosis and counseling to meet patients' expectations is of extreme paramount. Thus, proper assessment of patients who present with BPE and LUTS should be an important part of the work up process. Accurate diagnosis and identification of the cause will help to improve quality of treatment, optimize counseling, and improve treatment outcomes. Pressure flow urodynamic studies (PFUDs) are not only important tools that help to identify the underlying causes of LUTS; it is considered the "gold standard" for diagnosis of bladder outlet obstruction (BOO) in patients with enlarged prostate [1, 2]. However, there is a continuous debate on the value of using PFUDs and its association with improved outcomes.

Work Capacity of the Bladder During Voiding: A Novel Method to Evaluate Bladder Contractile Function and Bladder Outlet Obstruction

Background:

Work in voiding (WIV) of the bladder may be used to evaluate bladder status throughout urination rather than at a single time point. Few studies, however, have assessed WIV owing to the complexity of its calculations. We have developed a method of calculating work capacity of the bladder while voiding and analyzed the associations of bladder work parameters with bladder contractile function and bladder outlet obstruction (BOO).

Methods:

The study retrospectively evaluated 160 men and 23 women, aged >40 years and with a detrusor pressure at maximal flow rate (P_det Q_max) of ≥40 cmH₂O in men, who underwent urodynamic testing. The bladder power integration method was used to calculate WIV; WIV per second (WIV/t) and WIV per liter of urine voided (WIV/v) were also calculated. In men, the relationships between these work capacity parameters and P_det Q_max and Abrams-Griffiths (AG) number were determined using linear-by-linear association tests, and relationships between work capacity parameters and BOO grade were investigated using Spearman's association test.

Results:

The mean WIV was 1.15 ± 0.78 J and 1.30 ± 0.88 J, mean WIV/t was 22.95 ± 14.45 mW and 23.78 ± 17.02 mW, and mean WIV/v was 5.59 ± 2.32 J/L and 2.83 ± 1.87 J/L in men and women, respectively. In men, WIV/v showed significant positive associations with P_det Q_max (r = 0.845, P = 0.000), AG number (r = 0.814, P = 0.000), and Schafer class (r = 0.726, P = 0.000). Conversely, WIV and WIV/t showed no associations with P_det Q_max or AG number. In patients with BOO (Schafer class > II), WIV/v correlated positively with increasing BOO grade.

Conclusions:

WIV can be calculated from simple urodynamic parameters using the bladder power integration method. WIV/v may be a marker of BOO grade, and the bladder contractile function can be evaluated by WIV and WIV/t.

Correlation between penile cuff test and pressure-flow study in patients candidates for trans-urethral resection of prostate

Background

Aim of this study was to make a comparison between penile cuff test (PCT) and standard pressure-flow study (PFS) in the preoperative evaluation of patients candidates for trans-urethral resection of prostate (TURP) for benign prostatic obstruction (BPO).

Methods

We enrolled male patients with lower urinary tract symptoms candidates for TURP. Each of them underwent a PCT and a subsequent PFS. A statistical analysis was performed: sensitivity (SE), specificity (SP), positive predictive value (PPV), negative predictive value (NPV), likelihood ratio and ratio of corrected classified were calculated. Fisher exact test was used to evaluate relationships between PCT and maximal urine flow (Q_max): a p-value < 0.05 was considered statistically significant.

Results

We enrolled 48 consecutive patients. Overall, at PCT 31 patients were diagnosed as obstructed and 17 patients as unobstructed. At the subsequent PFS, 21 out of 31 patients diagnosed as obstructed at PCT were confirmed to be obstructed; one was diagnosed as unobstructed; the remaining 9 patients appeared as equivocal. Concerning the 17 patients unobstructed at PCT, all of them were confirmed not to be obstructed at PFS, with 10 equivocal and 7 unobstructed. The rate of correctly classified patients at PCT was 79% (95%-CI 65%-90%). About detecting obstructed patients, PCT showed a SE of 100% and a SP of 63%. The PPV was 68%, while the NPV was 100%.

Conclusions

PCT can be an efficient tool in evaluating patients candidates for TURP. In particular, it showed good reliability in ruling out BPO because of its high NPV, with a high rate of correctly classified patients overall. Further studies on a huger number of patients are needed, including post-operative follow-up as well.

International Prostatic Symptom Score-voiding/storage subscore ratio in association with total prostatic volume and maximum flow rate is diagnostic of bladder outlet-related lower urinary tract dysfunction in men with lower urinary tract symptoms

OBJECTIVES

The aim of this study was to investigate the predictive values of the total International Prostate Symptom Score (IPSS-T) and voiding to storage subscore ratio (IPSS-V/S) in association with total prostate volume (TPV) and maximum urinary flow rate (Qmax) in the diagnosis of bladder outlet-related lower urinary tract dysfunction (LUTD) in men with lower urinary tract symptoms (LUTS).

METHODS

A total of 298 men with LUTS were enrolled. Video-urodynamic studies were used to determine the causes of LUTS. Differences in IPSS-T, IPSS-V/S ratio, TPV and Qmax between patients with bladder outlet-related LUTD and bladder-related LUTD were analyzed. The positive and negative predictive values (PPV and NPV) for bladder outlet-related LUTD were calculated using these parameters.

RESULTS

Of the 298 men, bladder outlet-related LUTD was diagnosed in 167 (56%). We found that IPSS-V/S ratio was significantly higher among those patients with bladder outlet-related LUTD than patients with bladder-related LUTD (2.28±2.25 vs. 0.90±0.88, p<0.001). TPV was similar between the two groups; however, in contrast to patients with bladder-related LUTD, patients with bladder outlet-related LUTD had higher detrusor voiding pressure, lower Qmax values, and greater postvoid residual volumes. The combination of TPV≥30 ml and Qmax≤10 ml/sec had a PPV of 68.8% and a NPV of 53.5% for bladder outlet-related LUTD. When IPSS-T≥12 or IPSS-T≥15 was considered as an additional criterion, PPV increased to 75.0% and 78.5%, respectively, and the NPV decreased to 50.9% and 50.2%, respectively. When IPSS-V/S>1 or >2 was factored into the equation instead of IPSS-T, PPV were 91.4% and 97.3%, respectively, and NPV were 54.8% and 49.8%, respectively.

CONCLUSIONS

Combination of IPSS-T with TPV and Qmax increases the PPV of bladder outlet-related LUTD. Furthermore, including IPSS-V/S>1 or >2 into the equation results in a higher PPV than IPSS-T. IPSS-V/S>1 is a stronger predictor of bladder outlet-related LUTD than IPSS-T.

Bladder contractility and urethral resistance relation: what does a pressure flow study tell us?

Hydrodynamic analysis of a pressure flow study is the only reliable method to determine the presence or absence of a bladder outlet obstruction, especially benign prostatic obstruction. To interpret the results of pressure flow study in benign prostatic obstruction, understanding the outlines of the basic theory about evaluation of the relationship between bladder contractility and urethral resistance relation is of paramount importance. In contrast, hydrodynamic analysis of pressure flow study in conditions other than benign prostatic obstruction is complicated by the limits of theories about the hydrodynamics of the lower urinary tract. In this review, the proposed hydrodynamic theories about the relationship between bladder contractility and urethral resistance relation are outlined. Then, problems encountered in the application of hydrodynamic analysis of pressure flow study to diseases other than benign prostatic obstruction are discussed.

Normal urodynamic parameters in women: part II--invasive urodynamics

INTRODUCTION AND HYPOTHESIS

This literature review, providing reference ranges of normal variability in urodynamic parameters, is the second part of a two-part article. The first part addresses non-invasive urodynamics (UDS), while the second part addresses invasive techniques.

METHODS

Data were obtained through MEDLINE from articles published between January 1956 and February 2011, International Continence Society meeting abstracts, and standardization reports. Search terms included cystometry, urethral pressure profilometry, leak point pressure, video UDS, normal volunteer, pressure flow studies, and electromyography.

RESULTS

Normal values varied widely in the literature. However, with the help of clinical data, it was possible to define "normality" ranges for most of the different parameters.

CONCLUSIONS

Urodynamic evaluation of lower urinary tract (LUT) function is not a physiological test. However, it is still the best available tool for LUT function assessment. Even if normality in UDS can be defined, tests must always be interpreted against patient characteristics, complaints, and symptoms.

The comparative pressure-flow plot properties of radiological bladder neck and prostatic obstruction

OBJECTIVES

To test the hypotheses that: (i) significant differences should exist in pressure/flow data between radiologically determined bladder neck and prostatic obstruction; (ii) these differences should inform understanding of the pathophysiology of male outflow obstruction. The biomechanics of the voiding/pressure/flow plot imply that a urodynamic assessment trace should identify outflow obstruction and characterise the urethral viscoelastic properties. Micturating cystourethrograms (MCUG) images might provide a useful diagnostic dichotomy for testing these assumptions.

MATERIALS AND METHODS

The pressure/flow data from 71 men who also provided video-urodynamic imaging data that a radiologist could classify unequivocally as showing bladder neck obstruction (42) or prostatic obstruction (29) were analysed. The following variables were recorded: the detrusor pressure at initiation of voiding (P(det.open)); the detrusor pressure at the end of voiding (P(det.close)); the detrusor pressure at maximum flow rate (Q(max)), (P(det.)Q(max)), and Q(max). The urethral resistance relation (URR) was drawn onto the pressure-flow plot and the gradient of the URR, DeltaP(det)/DeltaQ, was calculated.

RESULTS

There were significant between group differences in P(det.open) (95% confidence interval of the difference 5.2-28.6, U = 352, P = 0.003); P(det.close) (0.2-15.0, U = 428, P = 0.034); P(det).Q(max) (0.0-18.9, U = 439, P = 0.05); Q(max) and DeltaP(det)/DeltaQ did not distinguish between the MCUG groups (95% confidence interval of the difference 2.3-18, U = 111; P = 0.004). The best-fit model from linear combinations of the data achieved an area under the receiver operator curve of 0.72 for discriminating between the MCUG groups.

CONCLUSIONS

The urodynamic assessment identified interesting and coherent biomechanical differences, and could distinguish between the obstructions with a moderate degree of accuracy.

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

AIMS

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

MATERIALS AND METHODS

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

RESULTS

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

CONCLUSIONS

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

Application of artificial neural network in prediction of bladder outlet obstruction: a model based on objective, noninvasive parameters

OBJECTIVES

An artificial neural network model previously described by us that was based on lower urinary tract symptoms yielded a modest prediction of bladder outlet obstruction. The aim of this study was to establish another model, using more objective parameters, that could better predict for bladder outlet obstruction.

METHODS

The records of 457 patients were used in the construction of the model. Of the 457 records, 300 were allocated to the training phase and 157 to the testing phase. All patients had the average flow rate, maximal flow rate, postvoid residual urine volume (PVR), and total prostate volume recorded. The results of the pressure flow study of those patients were considered the reference standard against which the artificial neural network was tested.

RESULTS

Three models were tested. Models 1 and 2 were based on a three-output design (ie, nonobstructed, equivocal, and obstructed). The only difference was the number of iterations. The accuracy of the first model was 60.5% compared with 46.5% for the second. For a third model, in which the equivocal pressure flow study results were added to the nonobstructed group, the accuracy rose to 72%. Deletion of equivocal cases (around 19% of the total) was associated with an accuracy of 76% in the prediction of obstruction.

CONCLUSIONS

An artificial neural network based on objective and noninvasive parameters could replace the pressure flow study in only 72% of cases. An accuracy of 76% in the detection of bladder outlet obstruction is rather impractical, because an equivocal zone has always been available on pressure flow study nomograms.

Urodynamics after TURP and HoLEP in urodynamically obstructed patients: are there any differences at 1 year of follow-up?

OBJECTIVES

To compare urodynamic findings after holmium laser enucleation of the prostate (HoLEP) and transurethral resection of the prostate (TURP) for the treatment of benign prostatic hyperplasia-related bladder outlet obstruction.

METHODS

From January to October 2002, 100 consecutive patients with benign prostatic hyperplasia with obstructive lower urinary tract symptoms were randomized to surgical treatment with either HoLEP (group 1, n = 52) or TURP (group 2, n = 48). All patients were preoperatively assessed using the International Prostate Symptom Score and quality-of-life question, total serum prostate-specific antigen measurement, transrectal ultrasonography, and complete urodynamic study. The operative time, catheterization time, and overall hospital stay were also recorded for both groups. All patients were assessed at 1, 6, and 12 months postoperatively using a complete urodynamic evaluation.

RESULTS

All patients were obstructed preoperatively (Schäfer grade greater than 2). Both groups were comparable in terms of age, total serum prostate-specific antigen level, International Prostate Symptom Score, and urodynamic results. At 1, 6, and 12 months of follow-up, no statistically significant differences were recorded in terms of detrussor pressure at maximal urinary flow rate, Schäfer grade (linear passive urethral resistance relation), maximal urinary flow rate, International Prostate Symptom Score, and quality-of-life score. In the HoLEP group, the catheterization time and hospital stay were significantly shorter. Transitory lower urinary tract symptoms after 3 months of follow-up and dysuria were more frequent in the HoLEP group than in the TURP group, although at 12 months of follow-up, the results were comparable.

CONCLUSIONS

Both HoLEP and TURP were equally effective in relieving bladder outlet obstruction. Although associated with greater early self-resolving irritative symptoms, HoLEP can guarantee a shorter catheterization time and hospital stay with longer operative times, proposing itself as an attractive alternative to standard TURP.

Two- and three-dimensional ultrasonographic findings in urethral stenosis with bladder wall trabeculation: case report

Female bladder outlet obstruction is uncommon. We report a case of bladder outlet obstruction secondary to urethral stenosis leading to bladder wall trabeculation. The patient presented at our clinic because of lower urinary tract symptoms including nocturia, urgency, bed wetting, hesitancy, straining to void, and incomplete emptying. Urodynamic study revealed a low maximum free uroflow rate, high residual urine volume, and low compliance on filling phase cystometry. Introital ultrasonography with two- and three-dimensional (2D and 3D) scanning displayed a constriction in the echolucent part of the lower-mid urethra with hyperechogenicity and a lattice-like appearance of the bladder wall. Cystourethroscopy confirmed urethral stenosis and bladder wall trabeculation. The voiding symptoms subsided after the urethral stenosis was relieved by urethral dilatation, but, despite some improvement, the irritative symptoms persisted. Introital ultrasonography with 2D and 3D scanning may help to clarify the cause of female bladder outlet obstruction.

Smooth muscle membrane organization in the normal and dysfunctional human urinary bladder: a structural analysis

PURPOSE

The decline in contractile properties is a characteristic feature of the dysfunctional bladder as a result of infravesical outlet obstruction. During clinical progression of the disease, smooth muscle cells undergo structural modifications. Since adaptations to constant changes in length require a high degree of structural organization within the sarcolemma, we have investigated the expression of several proteins, which are involved in smooth muscle membrane organization, in specimens derived from normal and dysfunctional organs.

MATERIALS AND METHODS

Specimen from patients with urodynamically normal/equivocal (n = 4), obstructed (n = 2), and acontractile (n = 2) bladders were analyzed relative to their structural features and sarcolemmal protein profile.

RESULTS

Smooth muscle cells within the normal urinary bladder display a distinct sarcolemmal domain structure, characterized by firm actin-attachment sites, alternating with flexible "hinge" regions. In obstructed bladders, foci of cells displaying degenerative sarcolemmal changes alternate with areas of hypertrophic cells in which the membrane appears unaffected. In acontractile organs, the overall membrane structure remains intact, however annexin 6, a protein belonging to a family of Ca2+-dependent, "membrane-organizers," is downregulated.

CONCLUSION

Degenerative changes in smooth muscle cells, which are chronically working against high resistance, are preferentially located within the actin-attachment sites. In acontractile bladders, the downregulation of annexin 6 might have a bearing on the fine-tuning of the plasma membrane during contraction/relaxation cycles.

Application of the Blaivas-Groutz bladder outlet obstruction nomogram in women with urinary incontinence

AIMS

To test the applicability of the Blaivas-Groutz nomogram for female bladder outlet obstruction in urinary incontinent women presenting in a general gynecologic practice and to determine how the nomogram results related to the presence of obstructive symptoms according to a standardized questionnaire.

METHODS

All women with complaints of urinary incontinence underwent multichannel urodynamic testing, free uroflowmetry and were asked to complete a standardized quality of life questionnaire consisting of the urogenital distress inventory (UDI). The patients were classified according to the Blaivas-Groutz nomogram.

RESULTS

One hundred and nine patients were classified according to the nomogram. Thirty-three patients (30.3%) were classified as unobstructed, 63 patients (57.8%) as mildly, 12 patients (11%) as moderately, and 1 patient (0.9%) was classified as severely obstructed. Fifty patients correctly completed the UDI. There was no significant difference (P = 0.61) in the score on the domain UDI obstruction between, according to the nomogram, obstructed and unobstructed patients. Only 18% of the obstructed patients had isolated voiding symptoms suggestive of obstruction. Forty-nine percent of the obstructed patients had urgency-frequency symptoms as well as voiding symptoms suggestive of obstruction. There was no correlation (Pearson, r = -0.06, P = 0.61) between the severity of the symptoms (assessed by the UDI scale) and the degree of obstruction (the four nomogram zones).

CONCLUSIONS

Application of the Blaivas-Groutz nomogram gave an unlikely high prevalence of obstruction in our patient group, which showed no correlation with symptoms when measured with the UDI.

Possible contribution of prostatic anterior fibromuscular stroma to age-related urinary disturbance in reference to pressure-flow study

Recently, we reported that the anterior fibromuscular stroma (AFMS) of the prostate has significant different innervation compared with the other glandular regions of the prostate. In healthy volunteers (n = 12) using transrectal ultrasound (US), or TRUS, monitoring during voiding, we observed dynamic change (p < 0.0001) of the thickness of the AFMS during voiding. The aim of this study was to reveal the possible functional contribution of the AFMS to micturition, as well as the age-related voiding dysfunction. In the patients (n = 56) with voiding dysfunction who underwent both pressure-flow study (PFS) for determining obstruction and TRUS monitoring during voiding, we measured the ultrasonic dynamic change of the lower urinary tract during voiding. In old men with voiding dysfunction, ultrasonic measurements of dynamic change in the AFMS (p < 0.01) as well as the opening urethra (p < 0.05) could contribute to diagnosing of the anatomical localization of obstructive lesions. The poor movement of AFMS could account for the age-related urinary disturbance in the patients without benign prostatic enlargement and without bladder neck obstruction.

Does Surgical Repair of Pelvic Prolapse Improve Patients’ Quality of Life?

OBJECTIVES

The aims of this study were to evaluate the efficacy of surgical repair in patients with pelvic prolapse, and to assess the postoperative quality of life (QOL).

METHODS

A total of 70 patients (mean age: 66.7 years) underwent transvaginal two-corner bladder neck suspension in combination with transvaginal hysterectomy (63 cases), and anterior with (49) or without (21) posterior colporrhaphy. The status of recurrence and complications were followed in all patients at a mean follow-up period of 32.0 months. Postoperative patients' quality of life (QOL) consisting of four items (sensation of vaginal bulging, urinary incontinence, difficulty to urinate, and health-related QOL) was assessed in 52 cases whose were followed at least two years (mean: 41.6 months, range: 24.3-69.1).

RESULTS

Sixty-eight patients (97%) were recurrence-free. Nine of the 39 (23%) patients with difficulty to urinate before surgery had persistent symptoms postoperatively. Multivariate analysis revealed that cystometric abnormalities, voiding symptoms at seventh days after surgery, and weak detrusor contraction were independent prognostic factors for persistent voiding symptoms. As for the QOL, all items had significant improvement at 13 months after surgery as compared to baseline condition. A longitudinal study showed improvement of these symptoms sustained at least up to four years.

CONCLUSIONS

This study suggests that surgical repair can achieve results with long-term durability as well as improving the QOL. In addition, assessment of the detrusor function may be needed for patients who complain difficulty to urinate in avoiding persistent such symptoms.

Factors associated with voiding function in women with lower urinary tract symptoms: a mathematic model explanation

AIMS

The aim of this study was to explore the relationship between voiding function and factors such as age, gravidity, parity, menopause, and anterior vaginal wall relaxation.

METHODS

One hundred twenty-five women were identified from urodynamic records, 83 premenopausal and 42 postmenopausal. All had had a sonographic assessment of the lower urinary tract and a full urodynamic study, including a pressure-flow study. None had diabetes mellitus, overt neurologic disease, pelvic surgery, anticholinergic medication or estrogen therapy, or voiding difficulty symptoms. Voiding parameters included the following urodynamic variables: maximum flow rate, average flow rate, residual urine, the ratio of residual urine to total bladder volume on spontaneous uroflowmetry, maximum flow rate, and detrusor pressure at maximum flow on a pressure-flow study.

RESULTS

Uroflow rates were significantly correlated with age, parity, and urethral mobility. As a whole, the scatter plots of maximum and average flow rates versus voided volume on uroflowmetry displayed a significant correlation (P < 0.0001 and P < 0.0001, respectively). But, there was no association between maximum flow rate and detrusor pressure at maximum flow in the pressure flow study (P = 0.132). Age, menopause, parity, and urethral mobility may have affected the correlation on uroflowmetry but have no effect on pressure-flow plot. On subgroup analysis, significant correlation was identified only in women aged between 30 and 70, with parity greater than three, and urethral mobility greater than 70 degrees. These groups all had a reduced urethral pressure profile.

CONCLUSIONS

Age, menopause, parity, and urethral mobility may change the hydrodynamics of the lower urinary tract and have varying impact on the voiding function by altering urethral distensibility. Moreover, poor detrusor power in the postmenopausal women may complicate the analysis of voiding function.

Effect of catheter size on urodynamic assessment of bladder outlet obstruction

OBJECTIVES

To examine the effect of cross-sectional catheter diameter on urodynamic measurement of bladder outlet obstruction as predicted by the Abrams-Griffiths nomogram.

METHODS

Thirty-one patients with symptomatic benign prostatic hyperplasia underwent free flow measurements followed by pressure-flow urodynamic evaluation using 5F and 10F urethral catheters in randomly assigned order. The measurements of voided volume, maximal flow rate (Qmax), postvoid residual volume, and detrusor pressure at maximal flow (PdetQmax) were compared. Data points were then plotted on the Abrams-Griffiths nomogram, and categorization of bladder outlet obstruction was assigned for each catheter size.

RESULTS

The use of 10F catheters resulted in both a significant decrease in Qmax and increase in PdetQmax compared with the use of 5F catheters. Of 31 patients, 10 (32%) were incorrectly categorized as obstructed according to the Abrams-Griffiths nomogram when the larger sized catheter was used, and 17 (55%) experienced migration from a less obstructed to a more obstructed category.

CONCLUSIONS

The use of 5F catheters allows for more accurate diagnosis of bladder outlet obstruction. In urodynamic evaluations, the larger size 10F catheters should be avoided, especially in patients with borderline symptoms.

Implications of abdominal straining in women with lower urinary tract symptoms

OBJECTIVES

To explore the urodynamic significance of abdominal straining during voiding in female subjects with lower urinary tract symptoms.

METHODS

We retrospectively reviewed a urodynamic database to identify the 180 patients who met the inclusion criteria for this study. None had a history of pelvic surgery, neuropathy, diabetes mellitus, or subjective complaints of voiding difficulty (poor stream, straining to void, hesitancy, or incomplete emptying). None had distortion or compression of the urethra or urodynamic findings of genuine stress incontinence, overactive detrusor, or hypersensitive bladder. All had undergone the pressure-flow study as part of a full urodynamic study to investigate the voiding mechanism. Of the 180 subjects, 100 women were premenopausal and 80 were postmenopausal. One half of the patients in each group had abdominal straining during voiding; the other half did not. Abdominal straining was defined as an increase in abdominal pressure of at least 10 cm H2O greater than baseline, regardless of duration and patterns. Differences in demographics, anatomy, and urodynamic study findings in those with and without abdominal straining were compared in each group.

RESULTS

In premenopausal women, the intravesical opening pressure differed significantly between those with and without abdominal straining (P = 0.011); in postmenopausal women, the significant urodynamic difference was the time to peak flow and minimal urethral resistance (P = 0.017 and 0.023, respectively). Menopause did not affect the voiding patterns.

CONCLUSIONS

Although the clinical manifestation is devoid of voiding difficulty, straining at voiding in female subjects with lower urinary tract symptoms is significantly associated with the urodynamic parameters signifying urethral obstruction, and is a compressive effect in premenopausal women and a constrictive effect in postmenopausal women.

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.

Modified insitu vaginal wall sling in stress incontinence

To assess the efficacy of a modified technique in stress incontinence, that is vaginal wall sling reinforced with two layers of vaginal wall sutured inferiorly. 27 patients with Type II incontinence, 4 with Type III and 14 with mixed type who completed two years follow up were included into the study. Cure, improvement and failure rates were 84.4%, 8.9% and 6.7% respectively. Temporary retention is observed in 30 of the patients, vaginal stenosis and pelvic pain in 1 and suture granuloma in 5 of the patients. Reinforced insitu vaginal wall sling which gives additional support to urethral hammock inferiorly offers a better solution to both types of stress incontinence.

Valsalva leak point pressure: steps toward standardization

Valsalva leak point pressure (VLPP) has been used as the urodynamic indicator of intrinsic sphincteric deficiency in patients with stress urinary incontinence. However, further validation of VLPP as a tool for diagnosis and assessment of treatment outcome has been delayed mainly because of the lack of a universally accepted standardized methodology. The urodynamic parameters in need of standardization for measurement of VLPP include urethral catheter size, zeroing of the transducer, patient position, bladder volume, type of stress, and timing of measurement. Such standardization likely will allow for further validation of VLPP and its use in distinguishing the right treatment options for the correction of stress urinary incontinence.

The relationship of the International Prostate Symptom Score and objective parameters for diagnosing bladder outlet obstruction. Part II: the potential usefulness of artificial neural networks

PURPOSE

The International Prostate Symptom Score (I-PSS) is used exclusively for evaluating patients with a prostate condition and following various treatment modalities. As previously demonstrated, there is poor or no correlation of bladder outlet obstruction diagnosed by pressure flow study with the symptoms projected by the I-PSS. Thus, we applied an artificial neural network model to assess patients with lower urinary tract symptoms.

MATERIALS AND METHODS

Data on 460 patients enrolled in part 1 of our study were entered into a multilayer feed forward, back propagation network.

RESULTS

In the training set of 305 patients the model predicted obstruction in 94% with 94% sensitivity and 68% specificity. In the test set of 155 patients it predicted obstruction in 87% with 87% sensitivity and 44% specificity.

CONCLUSIONS

The accuracy of the model for diagnosing obstruction based on the I-PSS is acceptable, considering that statistical models failed to demonstrate a correlation of symptoms with objective obstruction.

Urinary tract anomalies and dysfunctional voiding: a spectrum dictated by the influence of amniotic pressure upon fetal urodynamics

The etiologic basis of urinary tract anomalies and dysfunctional voiding largely remain unknown. However, the travel of urine from renal pelvis into the amniotic cavity under the pressures exerted by amniotic fluid satisfactorily explains the etiologic basis. Amniotic pressure is affected by the changes in maternal intraabdominal pressure. The intraabdominal pressure of the fetus is also dictated by the amniotic pressure. Amniotic pressure compresses the urethra throughout the length, and may increase both bladder leak point pressure and urethral resistance. Furthermore, the urine is propelled against amniotic pressure. These factors closely simulate outflow obstruction. Since the pressure within the bladder with minimal urine content reflects the intraabdominal pressure, intravesical pressure is also elevated during fetal life. Additionally, elevated intravesical pressures impair ureteral drainage. The compressive effect exerted by fetal intraabdominal pressure upon ureters, further elevate the pressure within the renal pelvis. While forwarding the urine against these pressures may result in anomalies of the urinary tract, the increased work load of the detrusor may act as a state of injury that forms the basis of dysfunctional voiding.

Is bladder outlet obstruction normal in elderly men without lower urinary tract symptoms?

The aim of the present study was to correlate basic voiding parameters, including uroflowmetry, symptom score, and residual urine volume with the results of pressure-flow studies applying the Abrams/Griffith nomogram, in a series of urologically asymptomatic elderly men. Twenty-nine consecutive male volunteers (median age, 66 years) without past or present urological complaints participated. Fifteen (52%) of the 29 subjectively normal men proved to have bladder outlet obstruction (BOO). Qmax <10 mL/s had a positive predictive value of 100% in diagnosing obstruction, whereas the predictive information of higher flow rates proved very modest. No significant difference existed between obstructed and unobstructed persons at any cutoff value concerning symptom score. The sensitivity as well as the positive predictive value of a residual urine volume >50 mL was zero. It is concluded that a surprisingly high prevalence of BOO in asymptomatic elderly men was demonstrated and that the correlation between pressure flow investigations and alternative diagnostic tests, i.e., flow rate, symptom score, and residual volume was weak in this group of men. It is suggested that a possible explanation for the high frequency of BOO observed in the evaluated asymptomatic men could be that the values defining obstruction have been set too low. Neurourol. Urodynam. 18:545-552, 1999.

Physiologic evaluation of the pelvic floor

This article has addressed the value, technique, rationale, and limitations of the commonly performed physiologic tests of the pelvic floor. Urodynamics provides a means for evaluation of the lower urinary tract and for assessment of the filling and emptying phases of the bladder. Neurophysiologic tests including EMG and nerve conduction studies offer methods to assess the neuromuscular integrity of the urethral and anal sphincteric mechanisms and the pelvic floor. Anorectal manometry studies provide a means of measuring pressure in the rectum and anal canal, rectal compliance, and anorectal reflexes and sensation in patients with anal incontinence and select patients with constipation. Colonic transit studies permit an assessment of functional constipation and may be helpful in the evaluation of patients in whom standard management of constipation has failed. Any test used in the evaluation of patients with pelvic floor dysfunction should be validated and found to be reliable. Most patients in need of complex physiologic evaluation are identified on the basis of their history and physical examination findings.

Assessment of lower urinary tract functional deficit in rats with contusive spinal cord injury

Traumatic spinal cord injury (SCI) produces lower urinary tract (LUT) dysfunction that has been studied in surgical transection models. Our aim was to assess LUT functional deficit in a clinically relevant model of incomplete SCI to investigate how partial preservation of supraspinal connections might affect LUT dysfunction. Standardized weight-drop contusion (10 g x 2.5 cm) or complete transection, was produced at T8 in female Sprague-Dawley rats. Behavioral tests were used to assess hind limb sensorimotor function at Day 1 after surgery and weekly thereafter. The urometric experiments were conducted on groups (n = 7) of uninjured rats and on injured rats during Weeks 1 and 2 after SCI (before and after spontaneous voiding was established) as well as Week 2 after a complete transection (n = 3). Under anesthesia, the bladder was continuously perfused with saline. Changes in bladder pressure and external urethral sphincter (EUS) electrical activity were monitored. The bladder was then dissected and weighed and both the bladder and spinal cord were fixed for pathoanatomical analyses. Our results indicate that several aspects of LUT dysfunction after contusive SCI were similar to transection, e.g., reduction of voiding efficiency (approximately 5% of normal value), decrease in inter-contraction interval (47%), increase in bladder capacity (8-fold), and weight (4.6-fold). One aspect appeared different from transection--partial recovery from acute bladder/sphincter dyssynergia. Because the coordination of bladder and EUS function is mediated by brainstem pathways, partial recovery of synergy after SCI was likely due to sparing of some relevant bulbospinal projections as was confirmed by retrograde transneuronal viral tracing.