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PubMed1998

Few patients with "chronic prostatitis" have significant bladder outlet obstruction.

OBJECTIVES: A high prevalence of significant bladder outlet obstruction has been reported among men diagnosed as having "chronic prostatitis." To evaluate the possibility that case selection may determine this high prevalence, we compared findings in patients referred directly to our Urodynamic Unit with that of patients evaluated in our Prostatitis Clinic. METHODS: The videourodynamics records of 201 men aged 18 to 50 years who presented to the Urodynamic Unit with any lower tract symptoms (irritative and/or obstructive with or without pain) were compared with the findings in 123 Prostatitis Clinic patients. The latter were evaluated for obstruction with flow rates and, if abnormal, by retrograde urethrograms and videourodynamics. RESULTS: Only 37 (18%) of 201 patients referred to the Urodynamic Unit had pain as a significant symptom and might have been diagnosed as having chronic prostatitis. Of these 37 patients, 4 (11%) had definite obstruction, 6 (16%) were equivocal, 6 (16%) were hypocontractile, 1 (3%) had pseudodyssynergia, and 7 (19%) had normal findings. The remainder had abnormalities of bladder filling (hypersensitivity in 11 [30%] and detrusor instability in 2 [5%]). Fewer of the 123 patients with prostatitis had obstruction (definite in 2 [1.6%] and equivocal in 1 [0.8%]) (P = 0.03), 2 (1.6%) had hypocontractile detrusors, and 2 had urethral strictures. CONCLUSIONS: Patients referred to the Urodynamic Unit with lower urinary tract symptoms and pain rarely have bladder outlet obstruction. However, they are significantly more likely to have bladder outlet obstruction than patients referred to the Prostatitis Clinic who can be screened for obstruction by history, flow rate, postvoid residual, and retrograde urethrogram.

Adolescent↗
PubMed1990

Short term functional effects of bladder outlet obstruction in the cat.

Experimental bladder outlet obstruction in cats was produced by surgical placement of a silastic cuff around the urethra. Two sizes of cuff were used to produce either moderate or severe obstruction. The following is a summary of the short-term effects on bladder function. Obstruction induced a significant increase in the in vivo voiding pressure, in proportion to severity of the obstruction. There were no significant differences between control and obstructed cats in bladder mass, response of the isolated whole bladder to field stimulation or bethanechol, response of isolated bladder strips to field stimulation, bethanechol and ATP, or muscarinic receptor density in the bladder body. Although there were no differences in bladder mass between control and obstructed bladders, the hydroxyproline concentration of the severely obstructed bladders was significantly reduced. Creatine phosphate concentration was also significantly reduced in obstructed bladders. Although all whole cat bladder preparations displayed spontaneous contractile activity during in vitro cystometry, the obstructed bladders had a greater amplitude and frequency of spontaneous contractions with a lower volume threshold. In addition, the obstructed bladders had a greater tetrodotoxin-resistant contractile response to field stimulation. These results suggest that the obstructed cat bladder can compensate for increased outlet resistance without induction of bladder hypertrophy or significant functional changes, as seen in both rat and rabbit.

Adenosine Triphosphate↗
PubMed1999

Metabolic basis for contractile dysfunction following chronic partial bladder outlet obstruction in rabbits.

Prior studies have shown that partial outlet obstruction of the rabbit bladder causes a progressive increase in bladder mass, a progressive decrease in the contractile response to different forms of stimulation, and a selective decrease in the activity of mitochondrial enzymes. In this investigation the contractile responses to field stimulation and bethanechol were directly correlated with the activity of citrate synthase as a function of both the duration of obstruction and the bladder mass. Partial bladder outlet obstruction was surgically induced in twenty New Zealand White rabbits. The bladders were then rapidly excised at 30, 40, 90, 105 or 150 days post obstruction. The contractile responses to field stimulation (32 Hz) and bethanechol (250 microM) were determined. The remainder of the bladders were frozen and used for citrate synthase activity determinations. The data were grouped for analysis both by the duration of obstruction and by the bladder mass. Chronic partial outlet obstruction caused a parallel decline in the activity of citrate synthase and in the response of the obstructed tissue to stimulation.

Animals↗
PubMed2000

Bladder outlet obstruction in women: definition and characteristics.

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

Cystoscopy↗
PubMed1990

Effect of bladder outlet obstruction on the morphology, physiology, and pharmacology of the bladder.

Bladder outlet obstruction secondary to benign prostatic hyperplasia induces numerous changes in bladder morphology, physiology, and pharmacology. These changes have been studied experimentally in various animal models, and while each species has advantages and disadvantages, it is unclear which is most like man. It has been shown that tissue hypertrophy leading to an increase in tissue mass develops rapidly after bladder outlet obstruction. Ischemia induced by the obstruction results in acute muscle dysfunction. The degree of functional impairment is directly related to the degree of tissue hypertrophy. However, the bladder contractile apparatus appears to have a surprising regenerative ability, such that recovery of bladder function becomes obvious 14 days after obstruction. Urodynamic changes include an increase in urinary frequency and voiding pressure and a decrease in voided volume. Clinically, involuntary bladder contractions are often present. Determination of which of these specific aspects of outlet obstruction the investigator is interested in studying will dictate the selection of the most appropriate animal model.

Animals↗
PubMed2004

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.

Adolescent↗
PubMed1998

Detrusor contraction duration as a urodynamic parameter of bladder outlet obstruction for evaluating men with lower urinary tract symptoms.

PURPOSE: Recent studies suggest that detrusor contraction duration increases with bladder outlet obstruction and correlates with the American Urological Association (AUA) symptom index. Since the detrusor contraction duration may also depend on detrusor contractility and bladder volume, its use alone in characterizing bladder outlet obstruction is debatable. Therefore, we studied the relationship between detrusor contraction duration and bladder outlet obstruction, bladder capacity, detrusor contractility and symptoms to determine whether detrusor contraction duration is a useful parameter for characterizing bladder outlet obstruction in men with lower urinary tract symptoms. MATERIALS AND METHODS: Pressure-flow studies were performed in men with lower urinary tract symptoms. Bladder outlet obstruction was defined as passive urethral resistance relation greater than grade II and contractility was determined from Schäfer's nomogram. Detrusor contraction duration was defined as the contraction time elapsed between the first rise in detrusor pressure from baseline to the time at which detrusor pressure returned to baseline at the end of voiding. AUA symptom index was attained from each patient and categorized as mild (0 to 7), moderate (8 to 19) and severe (20 to 35). RESULTS: Detrusor contraction duration was determined from 58 consecutive pressure-flow studies. This parameter was not significantly different among 23 patients with mild (116.7+/-34.0 seconds), 15 with moderate (102.7+/-61.9 seconds) and 9 with severe (89.2+/-44.4 seconds) AUA symptom index scores. AUA symptom index, as well as irritative and obstructive scores did not significantly correlate with detrusor contraction duration. Detrusor pressure at maximal flow was weakly correlated with detrusor contraction duration (r=0.322, p=0.014). However, detrusor contraction duration in 27 obstructed patients (111.6+/-53.7 seconds) was not significantly different from that of 31 nonobstructed patients (91.5+/-41.5 seconds) and it did not increase with the severity of bladder outlet obstruction. Detrusor contraction duration in 40 patients with good contractility (94.3+/-49.2 seconds) was significantly lower than in 18 patients with poor contractility (115.5+/-43.3 seconds). Detrusor contraction duration was significantly lower in nonobstructed patients with good contractility (72.0+/-21.7 seconds) compared with either nonobstructed patients with poor contractility (118.4+/-47.7 seconds) or obstructed patients with good contractility (112.5+/-58.0 seconds). There was no difference in detrusor contraction duration between nonobstructed patients with poor contractility and obstructed patients with good contractility. Multiple regression analysis showed that detrusor contraction duration can be best predicted by a combination of detrusor pressure at maximal flow, bladder capacity and contractility (r=0.576). CONCLUSIONS: Our study showed that detrusor contraction duration cannot distinguish patients with from those without bladder outlet obstruction, and it does not correlate with the severity of symptoms. Since our results also showed that detrusor contraction duration depends on several factors related to detrusor and outlet function, it cannot be used as a reliable parameter to diagnose bladder outlet obstruction.

Aged↗
PubMed1998

Predictability of conventional tests for the assessment of bladder outlet obstruction in benign prostatic hyperplasia.

BACKGROUND: The degree of bladder outlet obstruction (BOO) in benign prostatic hyperplasia (BPH) is most accurately quantified by pressure flow studies (PFS), although these studies are more invasive and complicated than conventional tests. We examined how precisely conventional tests predicted the PFS-assessed degree of BOO. METHODS: The study population consisted of 232 BPH patients who had undergone routine conventional tests and PFS. Correlation of the conventional test results with the degree of BOO assessed by PFS was examined by Spearman's correlation coefficients. Regression and subgroup analyses were performed to predict the degree of BOO using the conventional test results as the explanatory variables. RESULTS: The degree of BOO correlated with prostate volume, the degree of endoscopic obstruction, and to a lesser extent, with the maximum flow rate (Qmax) and age. The predictability of conventional tests alone, or in combination, for BOO, was approximately 60% to 70%, which is not acceptable for investigational use. However, almost all patients with a prostate volume larger than 30 mL, or with severe obstruction on urethroscopic findings, had an obstructed bladder outlet. CONCLUSION: PFS is mandatory when the precise evaluation of the degree of BOO is required, and patients are highly likely to have an outlet obstruction when they have a prostate larger than 30 mL, or severely obstructed posterior urethra on endoscopy.

Aged↗
PubMed2001

In-utero treatment of fetal bladder-outlet obstruction by a ureterocele.

Fetal bladder-outlet obstruction by ureteroceles is usually treated at birth. However, such obstruction may be detrimental to the health of the fetus and so in-utero correction is preferable. We describe the successful cytoscopy guided laser incision, with no complications, of a uterocele that was causing bladder-outlet obstruction in a fetus of 19 weeks and 6 days gestation.

Adult↗
PubMed1999

Positive bladder cooling reflex in patients with bladder outlet obstruction due to benign prostatic hyperplasia.

The bladder cooling reflex was evaluated in patients with bladder outlet obstruction to study the effect of obstruction on the afferent neural function of the bladder, especially on the C-afferents. The bladder cooling test was performed by infusion of 0 degree C saline into the bladder with simultaneous detrusor pressure measurement in 104 patients with bladder outlet obstruction due to benign prostatic hyperplasia. In 49 patients (47%) a positive cooling reflex was observed. This was defined as a rise in the detrusor pressure following cold saline instillation exceeding 15 cmH2O (range 15-130 cmH2O, mean 60.6 cmH2O; positive group). In the remainder of cases the pressure rise ranged from 0 to 12 cmH2O (mean 6.1 cmH2O; negative group). Bladder outlet obstruction may cause some alteration in the afferent neural function of the bladder, in particular of the C-afferent fibers.

Aged↗
PubMed2001

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

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

Female↗
PubMed2000

Characterization of ureteral dysfunction in an experimental model of congenital bladder outlet obstruction.

PURPOSE: Ureteral dysfunction is a significant sequela of congenital bladder outlet obstruction. However, the structural and functional alterations associated with ureteral dysfunction are not well defined. A model of fetal bladder obstruction in sheep was used to characterize the changes in ureteral smooth muscle, extracellular matrix (ECM) and functional properties in response to bladder outlet obstruction. MATERIALS AND METHODS: Partial bladder outlet obstruction was created in fetal sheep at gestational age 95 days via placement of a metal ring around the proximal urethra as well as ligation of the urachus. Ureters were harvested at 109 and 135 days (full term = 140 days) to determine the relative composition of smooth muscle, ECM and urothelium by morphometric analysis and to measure DNA and protein concentrations. Ureteral tissue from 135 day gestation obstructed and control sheep was harvested and immediately placed in Krebs solution. Smooth muscle strips (2-3 mm. x 7-8 mm.) were suspended in organ baths. The frequency and amplitude of spontaneous ureteral contractions was as well as the response to electric field stimulation (EFS) were determined. RESULTS: Bladder outlet obstruction caused a significant increase in ureteral weight, smooth muscle mass and total ECM at both 109 and 135 days gestation. Total ureteral DNA was greater in obstructed compared with sham ureters at 135 days gestation. Obstructed ureters demonstrated greater amplitude and frequency of spontaneous contractions as well as more pronounced response to EFS when compared to sham ureters. CONCLUSIONS: The fetal ureter responds to bladder obstruction with smooth muscle hyperplasia and hypertrophy which is associated with increased spontaneous activity and augmented response to EFS. ECM content is markedly increased indicating a shift in the balance of connective tissue synthesis and degradation. Congenital post-obstructive ureteral dysfunction therefore appears to be the result of dysregulated smooth muscle cell growth and altered ECM homeostasis producing abnormal ureteral contractility.

Animals↗
PubMed1993

Urolase laser prostatectomy in patients on warfarin anticoagulation: a safe treatment alternative for bladder outlet obstruction.

Three patients with symptomatic bladder outlet obstruction due to benign prostatic hyperplasia underwent laser prostatectomy using a Neodymium:YAG source delivered with the Urolase right-angle laser fiber. All patients had significant underlying medical problems, and all were fully anticoagulated with oral warfarin (mean prothrombin time 17 seconds). Two were in urinary retention with indwelling catheters preoperatively. Laser prostatectomy was performed in each case without change in the medical regimen, including continuous warfarin dosing. No complications occurred, and in particular, no early or late bleeding episodes were encountered. All are symptomatically improved and catheter-free on follow-up. Laser prostatectomy provides a new and safe therapeutic option in the management of these high-risk patients.

Aged↗
PubMed1997

[Clinical significance of residual urine volume in bladder outlet obstruction with benign prostatic hyperplasia].

Bladder outlet obstruction (BOO) with benign prostatic hyperplasia (BPH) was determined by pressure-flow studies. Residual urine volume was measured by urethral catheterization. Fifty-one patients with or without BOO were investigated for residual urine. The mean residual urine volume was 32.8 +/- 35.9 ml and 25.2 +/- 22.7 ml in BOO group (31 patients) and no BOO group (20) respectively. The range of residual urine volume was from 6 to 210 ml and from 3 to 88 ml in the two groups respectively. Residual urine volume was not statistically different between the BOO group and no BOO group (P > 0.05). The results of pressure-flow studies were significantly different between the BOO group and no BOO group (P < 0.01). Residual urine determination was not a reliable criterion for selection of patients for surgery. The cause of residual urine is not only BOO. The patients with BOO may present insignificant residual urine. It is evident that the absence of post-void residual urine does not rule out BOO.

Aged↗
PubMed2005

Evaluation of two techniques of partial urethral obstruction in the male rat model of bladder outlet obstruction.

OBJECTIVES: To perform a comparison to determine which of two methods of partial urethral ligation produces the most consistent outcome and fewest side effects. Such a study has not been previously reported. Partial urethral ligation is a means of causing reproducible bladder outlet obstruction. In the male rat model, partial urethral obstruction can be performed either by perineal incision and bulbous urethral ligation or retropubic incision and midprostatic obstruction. METHODS: Fifteen male Sprague-Dawley rats were studied. Five were selected for bulbous urethral obstruction through a perineal incision, five for midprostatic obstruction using a retropubic approach, and five for a sham operation through a perineal incision. RESULTS: The operative time was shorter and morbidity lower with the perineal approach compared with the retropubic approach. Inflammation or infection, or both, were seen in the prostate, bladder, proximal urethra, ureters, and kidneys in the rats in which a midprostatic obstruction was performed. The proximal urethra and prostate were mildly inflamed in those rats that underwent bulbous obstruction. Sham-operated rats exhibited mild prostatitis only. CONCLUSIONS: The perineal approach to the bulbous urethra is the method of choice for creating a partial urethral obstruction model of bladder outlet obstruction in the male rat.

Animals↗
PubMed2004

Delayed treatment of bladder outlet obstruction after sling surgery: association with irreversible bladder dysfunction.

PURPOSE: Our urethrolysis cohort demonstrated an unusual delay time to surgical treatment of bladder outlet obstruction. We determined whether urethrolysis outcomes, ie persistent bladder symptoms, were associated with time between sling and urethrolysis surgeries. MATERIALS AND METHODS: Retrospective analysis of all patients who underwent urethrolysis for post-sling voiding dysfunction between June 1997 and June 2002 was performed. We excluded from study 6 patients with a known history of overactive bladder symptoms, neurogenic bladder dysfunction and use of anticholinergic pharmacotherapy before stress incontinence surgery. The remaining 15 patients were stratified into 2 outcomes groups based upon the absence or presence of post-urethrolysis bladder storage symptoms. Patients (7) in group 1 have no current bladder symptoms. Patients (8) in group 2 still require anticholinergic drug therapy for significant bladder symptoms of frequency and urgency. Data collected for the 2 groups included mean age, existence of urinary retention before urethrolysis, mean time to urethrolysis in months, urethrolysis outcome based upon subjective bladder symptoms and followup duration. For comparison of mean age between groups the standard t test was used. Fisher's exact test was used to compare frequency of urinary retention before urethrolysis between groups. Lastly the Mann-Whitney U test was conducted to compare time to urethrolysis between groups. All statistical analyses were conducted using the SPSS software package (SPSS, Inc., Chicago, Illinois). RESULTS: There was no statistically significant difference between the groups with respect to age or frequency of urinary retention before urethrolysis. Time to urethrolysis for the whole cohort ranged from 2 to 66 months. Mean followup after urethrolysis was 17.3 +/- 22.9 months. Comparison of mean time between incontinence and urethrolysis surgeries between group 1 (9.0 +/- 10.1 months) and group 2 (31.25 +/- 21.9 months) demonstrated a statistically significant difference (p = 0.01). CONCLUSIONS: This urethrolysis population demonstrated an unusual delay time to surgical treatment of bladder outlet obstruction. We categorized the cohort according to absence or presence of persistent bladder storage symptoms, and found a strong association between persistent bladder symptoms and greater delay to urethrolysis.

Aged↗
PubMed1993

A critical comparison of methods proposed for quantification of bladder outlet obstruction.

Performance studies of parameters for bladder outlet obstruction in BPH patients before and after a TURP in terms of sensitivity and specificity can easily be criticized because in roughly 25% of the patients it is not clear if the clinical symptoms are related to increased outlet obstruction or impaired bladder contractility. This abstract presents objective alternatives.

Humans↗