Bladder outlet resistance

PURPOSE: We developed a method to objectively compare methods for the quantification of bladder outlet resistance. MATERIALS AND METHODS: We studied unselected voiding cystometries from 131 male patients. Several models proposed for bladder outlet resistance were fitted to the lowest monotonically increasing part (bottom) of the pressure flow plots. In conjunction with a parameter for bladder contractility, the model parameters were used as predictors of post-void residual greater than 20% of filled volume. RESULTS: The pressure decrease in relaxed bladder outlet was best described by a linear function of the flow rate. The flow rate independent and dependent parts of that function were statistically significant predictors for residual. However, they could be combined into 1 index that was as efficient as the 2 numbers separately in predicting residual. This index is the average pressure of the bottom of the pressure flow plot. CONCLUSIONS: We describe how different models for the quantification of bladder outlet resistance can be compared objectively on the basis of their ability to predict a significant post-void residual. Using this criterion in an unselected group of measurements, the average pressure of the bottom of the pressure flow plot performed best as an index for bladder outlet resistance quantification. It combines (or weights) 2 components (dependent and independent flow rates) without losing its power to predict post-void residual.     

相对膀胱出口梗阻的研究及临床意义

目的:研究相对膀胱出口梗阻参数与膀胱排空能力之间的关系,探讨其对于BPH患者的临床意义。方法:66名年龄在55岁以上并表现有下尿路症状的BPH患者被纳入本研究。所有患者均行尿动力学检查,对相对膀胱出口梗阻参数和排尿后剩余尿(PVR)之间的相关性进行研究。结果:相对膀胱出口梗阻参数(AG值/WFmax和URA/WFmax)与PVR之间的相关性强于AG值和URA。结论:相对膀胱出口梗阻参数能够更好地评价膀胱排空能力,有重要的临床指导意义。     

A PROBABILITY BASED SYSTEM FOR COMBINING SIMPLE OFFICE PARAMETERS AS A PREDICTOR OF BLADDER OUTFLOW OBSTRUCTION

PURPOSE: We explored the relationships of office assessment of lower urinary tract symptoms, transrectal ultrasound measurement and the bladder outlet obstruction index, as derived from pressure flow studies. We also developed and validated a multivariate analysis for predicting the bladder outlet obstruction index. MATERIALS AND METHODS: We evaluated 384 men with lower urinary tract symptoms using the International Prostate Symptom Score, maximum urine flow, post-void residual urine, transrectal ultrasound and urodynamic studies. Data were analyzed by multiple linear regression with continuous variables. A simple algorithm, that is the predicted bladder outlet obstruction index, was created using the best fit variables identified from a derivation set and assessed in a separate validation set. The predicted index was applied to predict the probability of actual obstruction according to office parameters. RESULTS: Maximum urine flow and total prostate volume predicted the bladder outlet obstruction index most completely (adjusted R2 = 0.50, F 75.9, p <0.0001), while other variables were not helpful. These variables were used to create the predicted bladder outlet obstruction index algorithm, antilog10 (2.21 - 0.50 log maximum urine flow + 0.18 log total prostate volume) - 50. In the 42% of patients with a predicted index of greater than 40 there was a 92% risk or positive predictive value of equivocal or worse obstruction, whereas a predicted index of less than 20 in 23% indicated a 4% risk of significant obstruction. CONCLUSIONS: The bladder outlet obstruction index can be predicted from maximum urine flow and prostate volume. Development of the predicted bladder outlet obstruction index algorithm enables the mathematical prediction of obstruction from these simple measures. Using the predicted bladder outlet obstruction index clinicians can determine the risk of obstruction in individuals. In 65% of patients we predicted equivocal or worse obstruction with greater than 90% confidence.     

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

AIMS: The aim of this study is to compare PUMA curves with different pathologic conditions causing bladder dysfunction in 158 men and 83 women. METHODS: PUMA results in terms of bladder outlet obstruction and detrusor contractility were compared in 92 men with benign prostatic hypertrophy (BPH) and p(ves) congruent with p(det) (i.e., p(abd) congruent with 0) with the results of the urodynamics operator's opinion, the provisional International Continence Society method, Abrams and Griffith's diagram, urethral resistence factor (URA), Sch?fer's diagram, and Watt factor. PUMA curves correlated reliably with different pathologic conditions such as obstructive BPH, orthotopic bladder, cystocele, the neurological bladder, and bladder diverticulum. Statistical analysis indicated excellent agreement between PUMA and URA; agreement with other methods was good in cases of obstruction and nonobstruction. In doubtful cases, as diagnosed by standard methods, PUMA agreed only with the Abrams and Griffith's diagram. PUMA and Wmax were in good agreement on detrusor con traction force. Agreement between PUMA and Sch?fer's diagram was excellent for patients with detrusor hypercontractility and good for patients with detrusor hypocontractility and normocontractility. PUMA is the only method applicable to women. It is easy to perform. When integrated with other diagnostic tests, it provides realistic data for diagnosis, medical or surgical therapy, and outcome.     

Treatment of primary bladder neck obstruction in women with transurethral resection of the bladder neck

PURPOSE: We describe the presentation, clinical characteristics, treatment and followup of a series of women with primary bladder neck obstruction (PBNO). MATERIALS AND METHODS: A patient data base was searched for women who underwent transurethral resection for bladder outlet obstruction diagnosed by videourodynamic study (VUDS) according to the Blaivas-Groutz nomogram for female bladder outlet obstruction between 1993 and 2002. A total of 37 women with obstruction were identified. Patients with neurogenic, traumatic, anatomical or iatrogenic causes of obstruction were excluded. Seven patients remained who had been diagnosed with PBNO, of whom all underwent transurethral bladder neck resection. Office records were reviewed for history, presentation, surgical treatment and clinical outcome. RESULTS: Seven patients were diagnosed with PBNO. Age was 39 to 81 years. Six of 7 patients presented with symptoms of obstruction, including a weak or intermittent stream and urinary hesitancy. These 6 patients had unremarkable physical examination findings with normal perianal sensation, anal sphincter tone and lower extremity reflexes. One patient presented with abdominal swelling, which on physical examination was found to be a markedly distended bladder containing more than 1000 cc urine. All patients had overt urethral obstruction on VUDS. In 6 of 7 patients obstruction was clearly at the vesical neck and in 1 the obstruction site was equivocal. Three patients were treated or had previously been treated pharmacologically with alpha-blockers. All patients were subsequently treated with intermittent self-catheterization. All patients then underwent transurethral bladder neck resection at the vesical neck and proximal urethra. Surgical specimens weighed 1 to 5 gm and showed urethral fragments or fibromuscular tissue without specific pathological findings. Followup was 1 to 10 years (median 3) and it included physical examination, uroflowmetry, post-void residual urine measurement and videourodynamic study. Six patients considered themselves cured of lower urinary tract symptoms and 1 was improved. In 1 patient the obstruction site was not clear. One patient had mild stress incontinence under rare circumstances not severe enough to require protective pads. The average change in flow was 6 +/- 10 vs 30 +/- 17 ml per second (p <0.03). The average change in voided volume was 194 +/- 170 vs 416 +/- 206 ml per second (p <0.06). Average change in post-void residual urine was 680 +/- 445 vs 173 +/- 366 ml (p <0.05). CONCLUSIONS: PBNO is an exceedingly rare condition, which is easily treatable when properly diagnosed by VUDS. The presentation of patients in urinary retention in middle age suggests that PBNO may be more common in less apparent forms than has previously been recognized.     

Transurethral incision of bladder neck for voiding dysfunction after radical hysterectomy: A report of 24 cases

Twenty-four women who had radical abdominal hysterectomy, and subsequently developed persistent high post-void residual urine underwent transurethral bladder neck incision. Persistent high post-void residual urine is defined as a residual urine volume 20% greater than the amount just voided. This was determined during a 24-hour period, 3 months or more after the radical hysterectomy. Our results indicated that the bladder outlet resistance before and after the procedure was 0.96±1.01 and 0.19±0.07 respectively (P<0.05). The mean ratios between residual urine and total bladder volume in 24 cases were reduced from 93.45±42.93% to 33.47±22.79% after the procedure (P<0.001). In addition, there was a significant decrease of functional urethral length, maximal urethral closure pressure and bladder outlet resistance. Based on the ratios of residual urine and total bladder volume, 7 patients were markedly improved, 10 were partially improved, 7 remained unchanged and none worsened. The overall improvement rate was 71% (17/24). Urinary incontinence was a rare complication which occurred in only one woman (4%).     

Noninvasive methods of diagnosing bladder outlet obstruction in men. Part 1: Nonurodynamic approach

PURPOSE: Many methods have been suggested for diagnosing bladder outlet obstruction, as defined by the gold standard of pressure flow studies. Difficulty arises when comparing completely different methods of diagnosing bladder outlet obstruction. A comprehensive review of the literature of the different methods used to diagnose bladder outlet obstruction by noninvasive means was performed with a view to allow such a comparison. MATERIALS AND METHODS: A MEDLINE search was done of the published literature covering until the end of 2004 on noninvasive methods used to diagnose bladder outlet obstruction. A direct comparison of all different methods was made using the sensitivity and specificity, positive predictive value and likelihood ratio of each test. For many of the techniques these values were calculated from the data presented in the article. RESULTS: A multitude of methods has been applied to diagnose bladder outlet obstruction. Broadly the methods were divided into nonurodynamic and noninvasive urodynamic methods. Nonurodynamic methods include symptoms, biochemical tests such as prostate specific antigen, ultrasound derived measurements such as post-void residual urine, bladder weight, prostate configuration and size, intravesical prostatic protrusion and the Doppler resistive index. Part 1 of the review explores and discusses the relative merits of the nonurodynamic based methods. CONCLUSIONS: Ultrasound derived measures such as bladder wall thickness and bladder weight offer a promising possibility of diagnosing bladder outlet obstruction noninvasively. However, further reproducibility and large accuracy studies with better methodological standards are required before they can replace pressure flow studies.     

Lack of correlation of the American urological association symptom 7 index with urodynamic bladder outlet obstruction

The objective of this study is to assess whether subjective information from the American Urological Association (AUA) Symptom 7 Index correlates with or predicts objective urodynamic parameters of bladder outlet obstruction. Seventy-five men, mean age 67 years (range 42–85 years), were referred for evaluation of “prostatism.” Evaluation consisted of the AUA Symptom 7 Index, noninvasive uroflow, post-void residual (PVR) urine measurement, and pressure-flow analysis. Men were categorized as “obstructed,” “equivocal,” or “unobstructed” according to the pressure-flow nomogram of Abrams and Griffiths. The total AUA 7 score, and all individual components, were compared with all invasive urodynamic parameters, and to the pressure-flow categories of obstructed, equivocal, or unobstructed. The AUA index severity categories (mild 0–7, moderate 8–19, and severe ≥20) were compared to the urodynamic pressure flow categories. Thirty-three men had severe symptoms, and 42 had moderate or mild symptoms. Forty men were urodynamically obstructed, and 35 men were equivocal or unobstructed. There was no correlation of any AUA index parameter (total symptom score, obstructive or irritative score component, or any individual question) with any noninvasive or invasive urodynamic parameter. The sensitivity and specificity of the AUA index for urodynamic obstruction was 42.5% and 54.3% respectively. Multivariable logistic regression analysis was used to determine whether clinical data easily obtained in the office setting (age, PVR, noninvasive maximum and average flow rates) could predict urodynamic obstruction when combined with any component of the AUA index. Only age was found to be a significant predictor of obstruction status (P = 0.026). Subjective information from the AUA Symptom 7 Index does not correlate with objective data assessing bladder outlet obstruction. Though the AUA index is a valid clinical tool, it should not be used to gauge the presence or severity of bladder outlet obstruction. © 1996 Wiley-Liss, Inc.     

前列腺增生症患者剩余尿与膀胱出口梗阻逼尿肌收缩力的相关性研究

目的 :探讨前列腺增生症 (BPH)患者剩余尿 (RUV )与膀胱出口梗阻 (BOO)、逼尿肌收缩力相关性。方法 :对 42例 BPH患者进行尿动力学检查。结果 :RUV与 BOO呈正相关 (r =0 .716 0 ,P <0 .0 1) ,与逼尿肌等容收缩压 (Piso)呈负相关 (r =- 0 .5 718,P <0 .0 1)。术前和术后的 RU V、尿道阻力因子 (URA )的差异有显著性意义 (P<0 .0 5 ) ,而术前和术后的 Piso差异无显著性意义 (P>0 .0 5 )。结论 :BPH患者 RUV的产生及增多是由于 BOO的加重和逼尿肌功能受损的共同结果 ,在病程的不同阶段 ,BOO和逼尿肌收缩力对 RUV的产生、增多及减少具有不同的作用和意义。     

Bladder overactivity in mice after 1 week of outlet obstruction. Mainly afferent dysfunction?

PURPOSE: Partial bladder outlet obstruction (BOO) is an established way to create bladder overactivity in animals. However, the micturition pattern achieved can vary considerably. We investigated the correlation between different micturition patterns, post-void residual urine, bladder capacity, bladder weight and in vitro contractility in a conscious mouse model of BOO. MATERIALS AND METHODS: Female MNRI mice with moderate (urethral) outlet obstruction were used. After 7 days of BOO cystometry without anesthesia was performed with the animal in a metabolic cage. Results were compared with those in unoperated controls and sham operated animals. In vitro contractility studies were performed. RESULTS: The majority of obstructed animals had an overactive voiding pattern with increased nonvoiding detrusor activity and without increased bladder weight. The remaining obstructed animals had significantly increased bladder weight and normal micturition volume but increased threshold pressure, bladder capacity and post-void residual urine. Subtle in vitro differences were found among the groups. CONCLUSIONS: The urodynamic characteristics of BOO mice correlate with bladder weight. However, detrusor overactivity in obstructed mice may develop without an increase in bladder weight and with only subtle changes in smooth muscle function, as investigated in vitro. This observation suggests that major disturbances caused by BOO may lie in the afferent arm of the signaling pathway.     

Validity of cuff-uroflow as a diagnostic technique for bladder outlet obstruction in males

OBJECTIVE: To investigate the validity of the cuff-uroflow method as a diagnostic technique for bladder outlet obstruction (BOO) in males. MATERIAL AND METHODS: A cross-sectional study was carried out on a consecutive series of 93 males (mean age 54.1 years) referred on presenting with lower urinary tract symptoms. The patients were subjected to measurement of the isovolumetric pressure (Pcuff.op) and its corresponding flow (Qcuff.op) by means of the cuff-uroflow method. Subsequently, a study was carried out of the conventional pressure-flow, calculating the degree of BOO according to the provisional International Continence Society (ICS) nomogram. RESULTS: There was a statistical relationship between the Pcuff.op and Qcuff.op values and the degree of BOO according to the provisional ICS nomogram: patients with BOO had a lower value of Qcuff.op and a higher value of Pcuff.op than those without BOO. Using a logistic regression model a nomogram was constructed to link Pcuff.op with Qcuff.op. This nomogram was divided into three areas (obstructed, indeterminate and not obstructed). Most patients (44.1% of the sample) were situated in the indeterminate area. If those patients were excluded, the nomogram gave a sensitivity for the diagnosis of obstruction of 100% and a specificity of 55.6%. The overall rate of correct diagnosis was 84.6%. CONCLUSIONS: The parameters obtained using the cuff-uroflow method were related to the presence of BOO. According to the provisional ICS nomogram, this method showed a better sensitivity than specificity for the diagnosis of BOO.     

Diagnosis of female bladder outlet obstruction and relevance of the parameter area under the curve of detrusor pressure during voiding: preliminary results

PURPOSE: The diagnosis of bladder outlet obstruction in women by pressure flow study may be difficult because there are several definitions of bladder outlet obstruction, several parameters and no standard cutoffs. We evaluated the ability of pressure flow studies to separate women into unobstructed, equivocal and obstructed groups. MATERIALS AND METHODS: In a prospective study 85 women with lower urinary tract symptoms underwent clinical evaluation, including physical examination, voiding cystourethrography, endoscopy, flow rate and post-void residual volume measurement. A pressure flow study was performed 15 days later. The pressure flow study parameters were maximum flow, post-void residual volume, detrusor pressure at maximum flow, vesical pressure at maximum flow, area under the curve of detrusor pressure during voiding and area under the curve of detrusor pressure during voiding adjusted for voided volume. After considering the clinical evaluation 2 urologists classified the patients into 3 groups, namely unobstructed, equivocal and obstructed, as the traditional classification. Linear discriminant analysis was then performed using the traditional classification and pressure flow study data. RESULTS: Mean patient age was 55 years (range 18 to 83). According to the traditional classification there were 36 unobstructed, 28 equivocal and 21 obstructed cases. Significant differences were noted in all pressure flow study parameters (analysis of variance p <0.05). Linear discriminant analysis showed that area under the curve of detrusor pressure during voiding adjusted for voided volume was the most statistically discriminating parameter. Of the cases 86%, 36% and 57% were identically categorized by the traditional and area under the curve of detrusor pressure during voiding adjusted for voided volume parameter classifications in the unobstructed, equivocal and obstructed groups, respectively. The other pressure flow study parameters showed less satisfactory results. CONCLUSIONS: Area under the curve of detrusor pressure during voiding adjusted for voided volume appears to be the most discriminating urodynamic parameter of female bladder outlet obstruction. Other studies are needed to test the reliability and validity of this new parameter.     

The relationship of detrusor instability and symptoms with objective parameters used for diagnosing bladder outlet obstruction: a prospective study

PURPOSE: Detrusor instability is a common urodynamic finding in patients with prostatic obstruction. In prospective fashion we evaluated detrusor instability in patients with lower urinary tract symptoms attributable to benign prostatic hyperplasia and determined its possible association with the degree of obstruction. MATERIALS AND METHODS: A total of 459 men with a mean age plus or minus standard deviation of 60.4 +/- 9.4 years who were investigated for lower urinary tract symptoms at our facility answered an Arabic standardized version of International Prostate Symptom Score and underwent simple uroflowmetry, outpatient cystoscopy and transrectal ultrasound. Invasive urodynamics, including filling and voiding cystometry, was done with pressure flow analysis according to the Sch?fer nomogram. Statistical significance was tested by the Mann-Whitney U and Wilcoxon rank sum tests. RESULTS: Of the 459 patients 108 (23.5%) had detrusor instability. Instability significantly affected patient symptom score and conception of quality of life. Moreover, instability significantly affected the degree of obstruction, as measured by the maximum flow rate, post-void residual urine, prostate volume and Sch?fer grade of obstruction. CONCLUSIONS: Detrusor instability affects patient symptoms and quality of life. It also signifies a more severe degree of obstruction in male patients with lower urinary tract symptoms and bladder outlet obstruction due to benign prostatic hyperplasia.     

Detrusor Contractility and Compliance Characteristics in Adult Male Patients With Obstructive and Nonobstructive Voiding Dysfunction

Purpose

To understand better the contractility and compliance characteristics of the detrusor in patients with varying degrees of outlet obstruction, we analyzed urodynamic studies in elderly men with obstructive and nonobstructive voiding dysfunction.

Materials and Methods

All patients were evaluated with video urodynamics, including cystometry, isometric tests, voiding profilometry and post-void residual measurement. Bladder compliance, detrusor contractility, detrusor reserve, detrusor instability and the severity of outlet obstruction were determined in each patient. Patients were stratified into 4 groups: urodynamically normal, detrusor instability, outlet obstruction and outlet obstruction with detrusor instability.

Results

A significant correlation was found between the maximum isometric contraction pressure and the severity of obstruction in 168 patients. Maximum isometric contraction pressure was significantly greater in patients with than without obstruction, independent of detrusor instability. Although compliance was not significantly different among the groups, the proportion of patients with poor compliance (less than 30 ml./cm. water) was lowest in the normal group. The detrusor reserve was significantly less in patients with chronic retention (post-void residual more than 200 ml.) than in those with lower post-void residuals.

Conclusions

The increase in detrusor contractility with increasing outlet obstruction suggests a compensatory response to obstruction. Furthermore, a decrease in bladder compliance does not appear to be a consistent finding in patients with outlet obstruction,although the proportion of patients with poor compliance is higher in the group with obstruction and/or detrusor instability than in those with normal urodynamic findings. The decrease in detrusor reserve in patients with high post-void residual volumes suggests that the detrusor reserve reflects the degree of detrusor decompensation.     

alpha1-Adrenergic blockers in young men with primary bladder neck obstruction

PURPOSE: We assessed the efficacy and safety of the mid term use of alpha1-adrenergic blockers for treating primary bladder neck obstruction in young and middle-aged men. MATERIALS AND METHODS: Between May 1998 and February 2001 primary bladder neck obstruction was diagnosed by videourodynamic study in 28 men younger than 55 years. The degree of obstruction was graded by the Schafer nomogram. Mean patient age and mean symptom duration were 39.3 years and 18.1 months, respectively. The presenting symptom was frequency in 22 cases (78.6%), urgency in 10 (35.7%), weak stream in 9 (32.1%), nocturia greater than 2 times in 7 (25%) and hesitancy in 7 (25%). A dose of 1 to 2 mg. doxazosin was administered at bedtime for at least 3 months. International Prostate Symptom Score (I-PSS), quality of life, uroflowmetry and post-void residual urine were assessed before and 3 months after medication. Improved urine flow was defined as at least a 2.5 ml. per second increase in the maximum flow rate. Improved symptoms was defined as more than a 50% decrease in I-PSS. Successful treatment was defined as improved urine flow and symptoms. RESULTS: Followup data were available in 24 patients. The medication period and followup were 7 and 12 months, respectively. Mean I-PSS plus or minus standard deviation decreased from 18.3 +/- 4.6 to 11.6 +/- 5.2 (p <0.01) and mean quality of life decreased from 4.1 +/- 1.1 to 2.6 +/- 1.0 (p <0.01). Mean maximum flow increased from 11.8 +/- 3.2 to 15.9 +/- 3.9 ml. per second (p <0.01). Mean post-void residual urine decreased from 80.2 +/- 17.1 to 48.5 +/- 10.3 ml. (p <0.01). Treatment was successful in 13 patients (54.2%) and 3 (12.5%) were free of medication for at least 6 months. More successful outcomes were noted in patients with high grades III to IV obstruction than in those with low grades 0 to II obstruction (80% versus 35.7%, p = 0.03). Before treatment higher detrusor pressure at maximum flow (70.1 versus 47.8 cm. water, p = 0.01) and lower maximum flow (10.6 versus 13.3 ml. per second, p = 0.02) were observed in patients with successful versus unsuccessful treatment, respectively. Differences in patient age, I-PSS, quality of life, prostate size and post-void residual urine were not statistically significant. No significant adverse effects were noted. CONCLUSIONS: alpha1-Blockers were effective and safe for treating young men with primary bladder neck obstruction.     

连续测定的压力-流率分析

目的 通过一组混合疾病的随机病例的回顾分析，探讨用不同方法对于同一病人的膀胱流出道梗阻(BOO)分级和膀胱收缩能力评价的可重复性。方法 连续2次测定22例的结果进行配对比较研究，按线性被动尿道阻力关系(linPURR)和膀胱流出道梗阻指数(BOOI)对每次测定作出BOO分级，用Schafer列线图和膀胱收缩能力指数(BCI)对膀胱收缩能力进行分级，比较四个参数前后两次分析结果的差异。结果 对于BOO以linPURR和BOOI分级P值分别为0．00l和0．057；对于膀胱收缩能力以Sehafer列线图和BCI分级P值分别为0．033和0．325。结论 linPURR对BOO分级的可重复性较差，而按公式计算BOOI方法简便，重复性好。     

Clinical diagnosis of bladder outlet obstruction in men with lower urinary tract symptoms: reliability of commonly measured parameters and the role of idiopathic detrusor overactivity

AIMS: There is no generally accepted consensus how to evaluate patients with lower urinary tract symptoms (LUTS) suggestive of bladder outlet obstruction (BOO). We have tried to determine whether the most frequently used objective variables as prostate volume, IPS-score, maximum flow rate, residual urine volume, functional bladder capacity, and pressure-flow study are reliable for diagnosis of BOO and we investigated the influence of idiopathic detrusor overactivity (IDO) on this condition. METHODS: A total of 153 men with LUTS and suspected BOO were systematically examined with routine investigation including digital rectal examination, transrectal ultrasound (TRUS), post-void residual urine volume measurement, uroflowmetry, and pressure-flow study. All patients completed IPS-score. Patients were divided into groups based on Sch?fer's grade of obstruction and incidence of IDO and clinical and urodynamical variables were compared. RESULTS: At baseline, 45.8% of the patients were urodynamically moderately obstructed and 37.9% were found to be severely obstructed. The grade of obstruction did not correlate with age. Prostate volume, post-void residual volume (PVR), and maximum flow rate correlated significantly with the degree of obstruction. The mean IPS-score remained almost unchanged throughout all obstruction groups. The incidence of IDO was 40.5% and increased from 16% in the minor obstruction group to 38.6% and 53.4% in the moderate and severe obstruction group, respectively. The patients with IDO were older, had larger prostates and were more obstructed. There was no impact of IDO on symptomatology of BOO. CONCLUSIONS: These data indicate that IPS-score does not achieve sufficient diagnostic accuracy and its role in the assessment of BOO is limited. The grade of obstruction is more related to prostate volume, PVR, and maximum flow rate. BOO and IDO seem to be related and have numerous mutual interactions.     

Comparison of passive urethral resistance relation and urethral resistance factor in analysis of bladder outlet obstruction in patients with benign prostatic enlargement

Analysis of the pressure/flow relation renders objective and detailed information on bladder outlet obstruction. The benefit of pressure/flow analysis for clinical and fundamental research questions, however, cannot be acknowledged without comparison of the different methods that exist. We compared one parameter analysis (URA) with two parameter (PURR) analysis in 99 consecutive patients with benign prostatic enlargement. The normal (instantaneous intrapatient) variability of both the PURR parameter Pvoid_min (minimal pressure during voiding) and the URA is ≈ 10–15 cm H₂O. Within these limits agreement between the two methods of analysis in the quantification of (minimal) outlet obstruction was observed in about 50% of the cases. However, when Qmax is less than 6 ml/s (in 49.5% of the patients) the URA number exceeds the value Pvoid_min in 96% of the cases. Predominantly this is caused by the fact that in the majority of these cases the type of bladder outlet obstruction is more constrictive than the URA curve, based on P_det at Q_max indicated. In patients with a low flow rate and/or a constrictive type of obstruction, the Pvoid_min resulting from PURR analysis indicates a lower minimal pressure during voiding compared to URA. © 1996 Wiley-Liss, Inc.     

Comparison of diagnostic criteria for female bladder outlet obstruction

PURPOSE: There is no universally accepted definition of bladder outlet obstruction in women. We compared 5 contemporary urodynamic definitions and determined how well they correlated with each other and with clinical suspicion of bladder outlet obstruction. MATERIALS AND METHODS: A total of 154 women who underwent videourodynamics were prospectively evaluated. Clinical obstruction was suspected when history, physical examination, symptoms and basic testing before urodynamics raised the suspicion. Women were classified as having obstruction based on 5 contemporary definitions, including 3 pressure flow cutoff point criteria, videourodynamic criteria and the Blaivas-Groutz nomogram. The McNemar Test was used to compare each definition to the others and to suspicion of clinical obstruction. RESULTS: Of the women 91 were evaluable, including 26 (29%) with obstruction by videourodynamic criteria, 28 (31%) with obstruction by 1998 cut point criteria, 18 (20%) with obstruction by 2000 cut point criteria, 13 (14%) with obstruction by 2004 cut point criteria and 38 (42%) with obstruction by the Blaivas-Groutz nomogram. Videourodynamic and 1998 cut point criteria were not significantly different from each other (78.9% concordance) and each agreed with the clinically obstructed category in the comparison. Compared to the other criteria, the Blaivas-Groutz nomogram overestimated obstruction, while 2004 cut point criteria tended to underestimate it. CONCLUSIONS: Each urodynamic definition of female bladder outlet obstruction has merit. Videourodynamic criteria and 1998 cut point criteria have the highest concordance. The Blaivas-Groutz nomogram overestimates obstruction compared to the other criteria. Therefore, it should not be used as the sole or standard definition of obstruction in women.     

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. © 1999 Wiley-Liss, Inc.