Diagnosing bladder outlet obstruction in women

PURPOSE: There are no universally accepted urodynamic criteria for diagnosing female bladder outlet obstruction. When accepted criteria for men are applied to women, the diagnosis of obstruction may often be missed, which is most likely due to differences in voiding dynamics. We propose video urodynamic criteria for diagnosing obstruction in women, and describe the urodynamic findings in those with and without obstruction. MATERIALS AND METHODS: We reviewed the charts of 331 women who underwent multichannel video urodynamics for nonneurogenic voiding dysfunction. Of these women 261 (mean age 55.8 years) had evaluable voiding pressure flow studies with simultaneous video fluoroscopy of the bladder outlet during voiding. At video urodynamics cases were classified as obstructed if there was radiographic evidence of obstruction between the bladder neck and distal urethra in the presence of a sustained detrusor contraction. Strict pressure flow criteria were not used. Maximum flow rate, detrusor pressure at maximum flow rate, post-void residual, bladder capacity and the incidence of detrusor instability were compared between obstructed and unobstructed cases. RESULTS: A total of 76 women met the criteria for obstruction (mean age 57.5 years), while 184 (mean age 55) did not. Causes of obstruction were dysfunctional voiding in 25 cases, cystocele in 21, primary bladder neck obstruction in 12, iatrogenic from incontinence surgery in 11, urethral stricture in 3, uterine prolapse in 2, urethral diverticulum in 1 and rectocele in 1. Obstructed cases had lower mean maximum flow rate (9 versus 20.2 ml. per second, p <0.0001), higher mean detrusor pressure at maximum flow rate (42.8 versus 22.1 cm. water, p <0.0001) and higher mean post-void residual (157 versus 33 ml., p <0.0001). There was no difference in bladder capacity (381 versus 347 ml.) or incidence of detrusor instability (45 versus 41%). CONCLUSIONS: Using the proposed video urodynamic criteria obstructed cases had significantly higher voiding pressures, lower flow rates and higher post-void residual than unobstructed cases, as expected. However, absolute values, especially for voiding pressure, are not as dramatic in women as in men. Pressure flow studies alone may fail to diagnose obstruction but simultaneous imaging of the bladder outlet during voiding greatly facilitates diagnosis.     

Early diagnosis of fetal bladder outlet obstruction

Prenatal ultrasonography has facilitated early diagnosis of in utero bladder outlet obstruction. This represents one of the earliest diagnoses of prune-belly syndrome and sheds light on the natural history of the bladder outlet obstruction in the fetus.     

Ultrasound diagnosis of bladder outlet obstruction in rabbits

One of the primary characteristics of partial outlet obstruction secondary to BPH is an increase in bladder mass commonly referred to as bladder hypertrophy. This condition has been simulated in rabbits by the partial ligation of the catheterized urethra. Ultrasonography has been utilized in both adult and pediatric urology to visualize the bladder and diagnose specific bladder disorders. The aim of the present study is to determine if ultrasonography can visualize bladder wall hypertrophy induced by obstruction. Partial outlet obstructions were created in NZW rabbits using standard methodologies, and then 5 to 7 days later, sonography was performed. The films were read by both the principal investigator and blinded investigators instructed to determine bladder wall thickness and from this predict the bladder weight. Then results were correlated with cystometrograms (CMGs) and whole bladder weights. Both the principal investigator and the blinded investigators were consistently able to distinguish obstructed from control bladders based solely on sonographic depictions of relative bladder wall thickness. In addition, the investigators were able to distinguish between low (control), medium, and high bladder weights based on sonography. The accuracy of predicting the bladder weights increased when cystosonograms were correlated with CMC studies. Thus, the degree of bladder hypertrophy can be accurately estimated by the combination of cmg and ultrasonography. © 1994 Wiley-Liss, Inc.     

膀胱出口梗阻患者充盈性膀胱测压参数的重测信度评价

目的研究良性前列腺增生(BPH)膀胱出口梗阻(BOO)患者充盈性膀胱测压检查测量参数的重测信度。方法BPH患者24例,平均年龄65岁。经直肠超声测定前列腺体积(62.7±30.4)ml。接受3次充盈性膀胱测压检查,分别间隔10min和4周,其间不给予相关治疗。记录膀胱开放时逼尿肌压力(Pdet.open)、最大逼尿肌压力(Pdet.max)、最小逼尿肌压力(Pdet.min.void)、最大尿流率时逼尿肌压力(PdetQmax)、最大尿流率(Qmax),计算AG值、线性被动尿道阻力相关性(LPURR)、尿道阻力指数(URA)。分别计算上述参数在重复测定过程中的重复测定误差、可重复性系数、相对可重复性系数和平均变异系数。结果在第2次相对于第1次测定时Pdet.open、Pdet.max、Pdet.min.void、PdetQmax、Qmax、AG值、LPURR、URA的相对可重复性系数分别为17.1%、16.3%、24.0%、12.5%、16.5%、18.7%、21.4%、23.7%,第3次相对于第1次测定时分别为19.7%、20.5%、32.7%、14.8%、24.0%、23.9%、27.3%、27.2%;第2次相对于第1次测定时的平均变异系数分别为22.9%、16.6%、24.5%、12.5%、19.9%、17.9%、20.7%、31.5%,第3次相对于第1次测定时分别为20.6%、18.8%、20.6%、13.2%、21.0%、16.7%、21.7%、29.7%。在所有参数中,平均变异系数最低的3个依次为PdetQmax、AG值及Pdet.max;相对可重复性系数最低的3个参数依次为PdetQmax、Pdet.open及Pdet.max。结论应用充盈性膀胱测压检查BPH伴BOO患者获得的参数结果中,PdetQmax不论在同一次检查中还是间隔较长时间再重复检查都具有较优的重测信度。     

女性膀胱颈抬高程度与膀胱出口梗阻相关性尿动力学分析

目的 探讨女性膀胱颈抬高程度与膀胱出口梗阻相关性尿动力学特点及临床意义.方法 实验组64例,筛选条件为主诉有尿频、尿急、排尿困难.排尿时间延长、下腹部胀痛不适等下尿路症状(Lower urinary tract syndrome,LUTS).对照组34例,为无LUTS症状的正常女性.所有患者均无神经系统疾病史,无糖尿病...     

Bladder outlet obstruction in women: difficulties in the diagnosis

OBJECTIVE: To identify the difficulties in diagnosing bladder outlet obstruction in women. MATERIAL AND METHODS: 53 women with a mean age of 37.2 (range 16-70) with chronic lower urinary tract symptoms and no neurogenic or organic diseases were examined. The prevalent symptoms were frequency (96%), urgency (92%) and nocturia (75%), and the mean duration of symptoms was 3.8 years. After pressure-flow studies and voiding cystourethrography were conducted, patients either underwent bladder neck or urethral incisions based on their diagnosis. These patients were subsequently subjected to follow-up uroflow studies. RESULTS: Abnormal uroflow curves were observed in 19 of 53 women. In 10 of them (52.6%), bladder outlet obstruction based on pressure-flow results was confirmed. Voiding cystourethrography results from these 19 women confirmed that 17 patients had bladder neck obstruction, while the remaining 2 had urethral obstruction. 16 of 19 were treated endoscopically, with 14 patients undergoing bladder neck incisions through the 5- and 7-o'clock positions and 2 patients having a distal urethral incision through the 12-o'clock position. In all of these 16 cases, there were both a statistical increase in the maximum flow rate (Qmax) as well as an improvement in the flow curves. Symptomatic improvement was observed in 12 of the 16 women subjected to surgical intervention. CONCLUSION: Bladder outlet obstruction exists in women with lower urinary tract symptoms. Pressure-flow studies and voiding cystourethrography are reliable modalities for confirming bladder outlet obstruction. Bladder outlet obstruction can be functionally or structurally caused.     

Relative bladder outlet obstruction

PURPOSE: Currently bladder outlet obstruction in males is defined by the provisional International Continence Society nomogram which is partly based on expert opinion and partly on measurements before and after transurethral prostate resection. Recently there has been some interest in the development of a similar nomogram for females. MATERIALS AND METHODS: We studied the possibility of defining bladder outlet obstruction based on a sign that it causes, namely post-void residual urine. RESULTS: The probability of relative post-void residual urine exceeding 20% of bladder capacity was modeled in males and females using 1 parameter, that is URA/w20 or the ratio of the obstruction parameter urethral resistance factor (URA)-to-the bladder contractility parameter Watts factor at 20% (w20). URA/w20 represents relative bladder outlet resistance or bladder outlet resistance normalized to bladder contractility. Above a threshold of URA/w20 = 6.8 in females and 8.2 in males a relative post-void residual exceeding 20% was noted in 90% of measurements. These thresholds may be used to define relative obstruction. The provisional International Continence Society nomogram for obstruction in males was transformed into an identical nomogram for females by equating the probabilities of post-void residual urine in each gender. The latter differed from that in men, in that the lines demarcating the zones were horizontal or flow rate independent but the intercepts were approximately the same at 20 and 40 cm. water. CONCLUSIONS: Instead of defining obstruction as an absolute level of bladder outlet resistance we suggest that it is better to define it relatively, that is as a level of bladder outlet resistance that depends on bladder contractility.     

Developing and validating a new nomogram for diagnosing bladder outlet obstruction in women

Objective

To develop and validate a nomogram for assessing bladder outlet obstruction (BOO) in women derived from concurrent P_det.Qmax and Q_max based on radiographic evidence of increased urethral resistance.

Patients and Methods

Retrospective analysis of prospectively acquired video‐urodynamics and clinical data of 185 women (development cohort) was performed. The P_det.Qmax were plotted against Q_max and cluster analysis was performed to determine an axis that best divided the definitively obstructed and unobstructed. Using data from a further 350 women (validation cohort), the sensitivity and specificity of the derived criterion was calculated. Finally, the data from both groups was pooled together and using binary logistic regression analysis, a nomogram was produced.

Results

Of the 535 patients in the two cohorts, (122 [22.8%]) demonstrated radiographic evidence of BOO. Cluster analysis identified the axis that best separates the radiographically obstructed and unobstructed as P_det.Qmax = 2*Q_max. Using the data from the validation cohort, the sensitivity and specificity for this was calculated as 0.94 and 0.93, respectively. A nomogram, representing the probability of BOO for concurrent P_det.Qmax and Q_max measurements was derived by pooling data from both cohorts. Alternatively, a female BOO index (BOOIf) may be calculated mathematically using the formula BOOIf = P_det.Qmax ? 2.2*Q_{max, that is,} BOOIf < 0, <10% probability of obstruction, BOOIf > 5 likely obstructed (50%) and If BOOIf > 18, obstruction almost certain (>90%).

Conclusion

A female BOO nomogram (the SG nomogram) with high sensitivity and specificity is proposed. The nomogram can be used to stratify the degree of BOO or assess response to treatment.     

膀胱出口梗阻指数在评估良性前列腺增生症膀胱出口梗阻中的应用

目的 探讨膀胱出口梗阻指数(BOON)在评估前列腺增生患者膀胱出口梗阻(BOO)中的意义.方法 对临床有下尿路症状,怀疑存在因前列腺增生症(BPH)导致膀胱出口梗阻的76例患者,测定前列腺体积(经直肠),最大自由尿流率(Qmax)和平均排尿量,通过公式计算BOON=前列腺体积(cm3)-3×Qmax(ml/s)-0.2×平均排尿量(ml).同时对患者进行压力.流率测定,计算AG值和Schafer梗阻级别,与BOON对照,分析利用BOON评估膀胱出口梗阻的准确性.结果 将本组患者年龄、前列腺体积、最大尿流率、残余尿量及BOON值,以AG作为因变量,同AG进行多元线性回归分析.整体回归方程中R=0.542(P=0.000),其中BOON值同AG值相关性最强(P=0.000).18例BOON值>-10,此时利用BOON判断BOO的敏感性为31%,特异性为100%,取BOON>-20时,敏感性为42.4%,特异性为88.2%;取BOON>-30时,敏感性为66.1%,特异性为82.4%;而取BOON>-40时,敏感性为77.9%,其特异性为64.7%.取BOON值-30作为分界点,在不明显降低特异性的同时,能够更敏感的判断BOO,BOON数值越大,利用BOON判断膀胱出口梗阻的特异性越高.结论 通过测定前列腺体积,最大自由尿流率(Qmax)和平均排尿量计算膀胱出口梗阻指数,取BOON>-30为分界点,是预测前列腺增生症是否存在膀胱出口梗阻的一种简易、无创方法,具有较好的特异性和敏感性.     

经超声逼尿肌厚度测定在无创诊断女性膀胱出口梗阻中的应用

目的 探讨经超声逼尿肌厚度测定在女性膀胱出口梗阻诊断中的应用价值.方法 93例伴有LUTS的女性患者,行压力流率测定过程中,当膀胱容量为250 ml或最大膀胱容量的50％时,应用7.5 MHz高频线纵超声探头测定膀胱前壁逼尿肌厚度.以Qmax≤12 ml/s以及最大尿流率时逼尿肌压力≥25 cm H2O(1 cm H2O =0.098 kPa)作为诊断女性膀胱出口梗阻的标准,将患者分为梗阻及非梗阻两组,比较两组年龄、尿动力学参数及逼尿肌厚度的差异.应用相对工作特征曲线评价逼尿肌厚度测定作为诊断工具的价值. 结果 梗阻组42例,非梗阻组51例.两组年龄分别为(61.2±8.3)、(59.9±7.7)岁(P=0.44),最大膀胱灌注容量分别为(292.2±82.3)、(308.1±87.5)ml(P =0.37),组间比较差异均无统计学意义;两组最大逼尿肌压力[(43.1±11.2)、(16.2±7.1)cm H2O,P=0.00]、最大尿流率时逼尿肌压力[(34.3±8.2)、(13.1±7.8)cm H2O,P=0.00]、Qmax[(7.4±3.2)、(17.4±4.1)ml/s,P=0.00]、排尿量[(157.1±63.7)、(251.2±77.4)ml,P=0.00]、残余尿量[(117.5±71.3)、(37.7±18.1)ml,P=0.00]及逼尿肌厚度[(1.8±0.3)、(1.4±0.2)mm,P =0.00]比较差异均有统计学意义.当临界值≥1.9 mm时,特异性和阳性预测值均为100％,敏感性为38％,阴性预测值为62％.其曲线下面积为0.88±0.06. 结论 经超声逼尿肌厚度测定诊断女性膀胱出口梗阻具有无创、方便、可靠的特点.当临界值≥1.9 mm时,具有较高的特异度和阳性预测值,在一定程度上可取代压力流率测定.     

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.     

Test-retest variation of pressure flow parameters in men with bladder outlet obstruction

PURPOSE: We assess short-term (5 to 10 minutes) and long-term (24 weeks) test-retest changes of repeated pressure flow examinations. MATERIALS AND METHODS: The pressure flow charts of 84 patients with benign prostatic enlargement and bladder outlet obstruction who had received either androgen suppressive therapy or placebo were reviewed retrospectively. Pressure flow examinations were performed at baseline, and at weeks 24 and 48. Each pressure flow session included 3 sequential voids. RESULTS: Median detrusor opening pressure, maximum detrusor pressure, detrusor pressure at maximum flow rate and minimum voiding pressure decreased statistically significantly from void 1 to 2, ranging from 9.5% to 15.8%. From void 2 to 3 during the same pressure flow session there was a further reduction in obstruction parameters. Median Abrams/Griffiths number was 10.7% lower at void 2 compared to void 1 (p <0.0001) and the urethral resistance algorithm was 3.2% lower (p <0.0001). Long-term test-retest changes from baseline to week 24 and from week 24 to week 48 for the pressure flow parameters studied were negligible. CONCLUSIONS: Changes in pressure flow parameters at short-term test-retesting are considerable and probably of clinical significance. The standard pressure flow nomograms, which are based on single void pressure flow studies, might need modification when applied to repeat void studies.     

Urodynamic assessment of bladder-outlet obstruction in women

Bladder-outlet obstruction (BOO) in women has become an increasingly recognized entity over the past several years. This is partly because of the greater number of anti-incontinence surgeries being performed, which can infrequently result in iatrogenic obstruction; and partly because of improvements in the ability to diagnose and recognize BOO. In this review, the symptoms associated with BOO in women, and whether these symptoms can reliably predict the presence of BOO, will be discussed. The incidence of BOO following surgical anti-incontinence procedures and the urodynamic diagnosis of BOO in women, detailing the various criteria that have been proposed, are also reviewed.     

良性前列腺增生患者前列腺体积参数与膀胱出口梗阻的相关性研究

目的探讨前列腺体积参数对良性前列腺增生（BPH）患者膀胱出口梗阻（B00）及其程度的诊断价值。方法对BPH患者行自由尿流率检查、压力-流率测定和经直肠前列腺B超检查，测量最大尿流率、Shaefer梗阻级别、AG数、前列腺体积（PV）、移行带体积（TZV）和移行带指数（TZI）。结果共有62例BPH患者入选。PV、TZV、TZI与Qmax的相关系数分别为-0．105、-0．173和-0．258。P值均〉0．05。PV、TZV和TZI与Sharer梗阻级别的相关系数分别为0．277、0．315和0．200。P值均〈0．05。PV、TZV和TZI与AG数的相关系数分别为0．263、0．277和0．282，P值均〈0．05；当40〈PV≤60ml时。PV与AG数呈正相关（r=0．263，P〈0．05）；TZI：0．3是BOO的一个分界点。TZI〉0．3者的AG数明显大于PV≤0．3者（P〈0．05）。结论前列腺体积参数可以预测BPH患者B00及其程度。     

男性原发性膀胱颈梗阻的尿动力学特点

目的 评价原发性男性膀胱颈梗阻的尿动力学表现.方法 回顾性分析23例男性原发性膀胱颈梗阻之尿动力学改变,包括尿流率、残余尿量及多通道尿动力学检查,并结合排尿期膀胱尿道造影、膀胱镜检查进行分析.结果 所有病例尿流率异常,可表现为最大尿流率降低,尿流曲线为钟型达峰时间延长或低平型.压力-流率检查可出现三型:高压-低流、正常压-低流、低压-低流,膀胱颈开放时间延迟在三型中均有出现.结合排尿期膀胱尿道造影、膀胱镜检查分析对确定诊断有重要意义.结论 普通尿动力学检查对原发性膀胱颈梗阻可作出初步诊断,明确诊断需结合排尿期膀胱尿道造影.     

Urodynamic evaluation of bladder neck obstruction in chronic prostatitis

Urodynamic assessment was performed in 50 patients with symptoms which supported a diagnosis of chronic prostatitis and commonly suggested outflow obstruction. Twenty-three patients had bladder instability with an equal incidence with or without obstruction; this was demonstrated in 30 patients and was localised to the bladder neck in 24 and to the prostate in 6. A sensory problem presented on urodynamic testing in 26 patients (52% of the entire series), with a lower incidence (43%) in the obstructed group. Posterior urethritis was found in 28 (78%) of 36 patients subjected to cystourethroscopy. Endoscopic findings were suggestive of obstruction in 20 (95%) of 21 patients with urodynamic evidence of outflow obstruction and the sites of obstruction generally corresponded. The studies have provided urodynamic evidence that bladder neck obstruction could be a significant though not a predominant factor in the aetiology of the clinical syndrome of chronic prostatitis.