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PubMed1999

Up-regulation of endothelin-B (ETB) receptors and ETB receptor-mediated rabbit detrusor contraction in partial bladder outlet obstruction.

OBJECTIVE: To investigate, in a rabbit model of bladder outlet obstruction (BOO), whether ETB receptors initiate any contractile activity, and to assess the density of these receptors. MATERIALS AND METHODS: Partial BOO was produced in male New Zealand White rabbits, with age-matched sham-operated rabbits acting as controls. One and 3 weeks later, the detrusor and bladder neck strips were incubated in organ baths with either BQ788 (an ETB antagonist), BQ123 (an ETA antagonist) or vehicle. Concentration-response curves were constructed using IRL-1620 (a selective ETB agonist). Low-resolution autoradiography was performed on serial detrusor and bladder neck sections from control and partial BOO (3-week) rabbits using radioligands for ETA and ETB. RESULTS: In strips from controls and after 1 week of partial BOO, IRL-1620 induced no contractions, but after 3 weeks of BOO, IRL-1620 induced significant concentration-dependent detrusor contractions (producing 12%, 25% and 70% of the KCl response at 10-8, 10-7 and 10-6 mol/L, respectively). The ETA antagonist had no effect on IRL-1620-mediated contractions. In contrast, the ETB antagonist completely abolished these contractions. Autoradiography showed the presence of ETA and ETB receptors in the detrusor and bladder neck of normal and obstructed animals, and a significant up-regulation of ETA and ETB receptors only in the obstructed detrusor smooth muscle. CONCLUSIONS: In BOO, ETB receptors initiate detrusor contractile activity. This is a time-dependent process that may depend on the up-regulation of ETB receptors in the detrusor. Therefore, ETB receptors may play a role in the pathophysiology of partial BOO.

Animals↗
PubMed2006

Vesicoamniotic shunting using a double-basket catheter appears effective in treating fetal bladder outlet obstruction.

BACKGROUND: To estimate the effect of vesicoamniotic shunting using a double-basket catheter on treating fetal bladder outlet obstruction. METHODS: A retrospective study involving 8 prenatally diagnosed bladder outlet obstruction cases that underwent vesicoamniotic shunt placement using a double-basket catheter from 1998 to 2004. Patients were followed-up for prenatal and neonatal outcome analyses. RESULTS: Vesicoamniotic shunting was performed in 8 fetuses aged between 13.7 and 25.4 weeks' gestation (mean+/-SD, 19.7+/-3.5 weeks). Final diagnoses included 5 posterior urethral valves, 1 cloacal anomaly, 1 urethral stenosis, and 1 unknown. There were no maternal complications associated with the procedures. One woman diagnosed as having a fetus with posterior urethral valves decided to terminate her pregnancy and one fetus died in uterus spontaneously. Six women delivered live babies, and one baby required postnatal ventilatory support. Postnatal follow-up ranged from 3 to 60 months. Of the 6 newborns, 4 survived with normal renal function, 1 had renal insufficiency, and 1 died of renal failure at 3 months of age. CONCLUSIONS: Vesicoamniotic shunt placement using a double-basket catheter may be effective in improving perinatal and neonatal outcomes through long-term decompression of the fetal urinary tract in carefully selected cases.

Amnion↗
PubMed2003

Alterations in cholinergic and neuropeptide innervation of urinary bladder following partial bladder outlet obstruction.

Posterior urethral valves (PUV) are the most common cause of bladder outlet obstruction (BOO) in infancy. Bladder instability, poor compliance and myogenic failure are responsible for the poor long-term prognosis in these patients. Previous studies have reported abundance of sensory neuropeptides, e.g. substance P (SP), calcitonin gene-related peptide (CGRP), vasoactive intestinal polypeptide (VIP) and acetylcholinesterase (AchE) nerves in the urinary bladder. We hypothesized that the functional changes in the bladder following BOO are due to alteration in cholinergic and sensory neuropeptide innervation. We therefore investigated cholinergic and sensory innervation of urinary bladder following BOO. Fifteen immature male guinea pigs (Hartley strain) 3-4 weeks old and weighing approximately 250 g. underwent placement of a silk ligature around the bladder neck to induce BOO. Controls included 5 sham-operated animals. The animals were killed 1, 2 and 4 weeks following obstruction, respectively. Whole-mount preparation and conventional sections of bladder wall were performed. AchE histochemistry, and single-label immunofluorescence histochemistry for SP, CGRP and VIP were utilized. Light microscopy and laser scanning confocal microscopy were used to assess the results. AchE staining showed marked increase in cholinergic innervation density within the suburothelial region following BOO. The staining for SP, CGRP and VIP demonstrated marked reduction in sensory nerve density within the suburothelial region 1 week following BOO and the lack of sensory innervation 4 weeks after BOO. The marked reduction in sensory innervation of the bladder and simultaneous increase in cholinergic innervation following BOO may lead to bladder instability and decrease in bladder compliance.

Animals↗
PubMed2004

[Analysis of the diagnostic criteria of bladder outlet obstruction in benign prostatic hyperplasia].

OBJECTIVE: To analyze the value of the diagnostic criteria for bladder outlet obstruction in benign prostatic hyperplasia (BPH). METHODS: A total of 358 patients with BPH were divided into 3 grades according to fibrous urethrocystoscopy information on the severity of obstructions, which were classified as Grade 1 (slight), Grade 2 (moderate), and Grade 3 (severe). By Schäfer's graph they were divided into 7 grades, represented by 0 to VI. We analyzed the volume of prostate, maximum flow rate (Qmax), residual urine volume, International Prostatic Symptom Score (IPSS) and detrusor instability. Statistical analysis ANOVA (analysis of variance) was made, spearman correlation evaluated and the coefficient of determination measured. RESULTS: Of all the patients, 27 were classified as Grade 1, 236 as Grade 2 and 95 as Grade 3. Eighty-four patients had detrusor instability. The volumes of the prostate ranged from 16 ml to 145 ml, averaging (47.04 +/- 15.61) ml. The mean maximum flow rate was (10.02 +/- 2.12) ml/min and the mean residual urine volume was (84.06 +/- 36.50) ml. With the increase of the severity of obstruction, the volume of the prostate increased (F = 4.216, P < 0.05), IPSS rose (F = 8.408, P < 0.001), the maximum flow rate decreased (F = 22.43, P < 0.001), the residual urine volume rose (F = 163.232, P < 0.001), the incidence of detrusor instability increased (F = 23.637, P < 0.001) and Schäfer's grades were elevated (F = 202.897, P < 0.001). The volume of the prostate, the maximum flow rate (Qmax), residual urine volume, IPSS detrusor instability and Schäfer's grades were all correlated significantly with the severity of the obstruction. The correlation index and coefficient of determination were r = 0.29, R2 = 0.08; r = 0.35, R2 = 0.12; r = -0.69, R2 = 0.47; r = 0.60, R2 = 0.36; r = 0.33, R2 = 0.11; r = 0.72, R2 = 0.52; respectively. The correlation between the urethrocystoscopy information and Schäfer's graph on the severity of the obstruction were the best criteria of all. CONCLUSION: The severity of the obstruction at urethrocystoscopy correlates well with that at urodynamic investigation. Such criteria could improve the sensitivity and specificity of the diagnosis of bladder outlet obstruction.

Aged↗
PubMed2006

[Treatment of bladder outlet obstruction secondary to suburethral tape by section of the tape].

OBJECTIVES: To determine the results of treatment of chronic urinary retention secondary to bladder outlet obstruction complicating retropubic suburethral insertion of Tension-free Vaginal Tape (TVT) by section of this tape. MATERIAL AND METHODS: Between June 2000 and December 2004, 30 women with a mean age of 63.5 +/- 11.6 years underwent a single lateral urethral section of Tension-free Vaginal Tape to treat bladder outlet obstruction secondary to retropubic suburethral TVT insertion. Success was defined by resolution of the symptoms, a maximum urine flow rate greater than 15 ml/s and a post-voiding residual less than 50 ml and failure was defined by persistence of at least one of these three criteria. RESULTS: The mean interval between TVT placement and tape section was 12.7 +/- 14.7 months. The mean follow-up was 25.8 +/- 7.8 months. The cure rate was 70%. One complication (a bladder wound) was observed. Postoperatively, two patients (70%) developed recurrence of stress urinary incontinence. CONCLUSION: The treatment of chronic bladder outlet obstruction after retropubic TVT placement to treat stress urinary incontinence by single lateral urethral section of this tape is a simple and effective technique with low morbidity, accompanied by a very low urinary incontinence recurrence rate.

Female↗
PubMed2000

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

OBJECTIVES: To analyze the intrarater and interrater reliability of a newly developed noninvasive urodynamic technique based on color Doppler ultrasound for the evaluation of bladder outlet obstruction. We previously demonstrated the feasibility of this new technique. METHODS: Color Doppler ultrasound urodynamic evaluations were performed on 31 men with and without bladder outlet obstruction. An ultrasound image-directed Doppler system with a 3.75-MHz probe operated by a remote control robotic manipulator was used to obtain color scale data using the transperineal approach in men during voiding. We measured the flow velocities in the distal prostatic (V1) and membranous urethra (V2) and used them to obtain the velocity ratio (VR = V1/V2). Combining this information with simultaneous uroflowmetry, the functional cross-sectional area of the distal prostatic urethra (A1) was calculated. These parameters were independently reinterpreted by an inexperienced investigator using the color image data stored in a personal computer. The intrarater and interrater reliability for VR were assessed using a classification based on cutoff values previously shown to indicate the presence or absence of obstruction. RESULTS: The retest correlation using Spearman's rho for VR in terms of intrarater and interrater reliability was 0.95 and 0.57, respectively; that for A1 was 0.97 and 0.64, respectively. Using a VR of less than 1.1 (to indicate the absence of obstruction) and a VR greater than 1.6 (to indicate the presence of obstruction) for classification, intrarater and interrater agreement occurred in 93.6% to 96.8% and 77.4% to 83. 9% of cases, respectively. CONCLUSIONS: The color Doppler ultrasound urodynamic technique for noninvasive evaluation of bladder outlet obstruction can be performed with reasonable reliability.

Adult↗
PubMed1991

Bladder outlet obstruction versus impaired detrusor contractility: the role of outflow.

The uroflow curves of 45 men with either bladder outlet obstruction or impaired detrusor contractility were retrospectively reviewed. The definitive diagnoses were attained by clinical and video-urodynamic studies with simultaneous detrusor pressure and uroflow measurements. Eight parameters were analyzed to determine if uroflow can differentiate obstruction from impaired contractility. There were no differences between the 2 groups in any of the parameters. This finding suggests that uroflowmetry as a single examination cannot distinguish between bladder outlet obstruction and impaired detrusor contractility.

Aged↗
PubMed1993

Urodynamic effects of finasteride in the treatment of bladder outlet obstruction due to benign prostatic hyperplasia.

Urodynamic effects of the 5-alpha-reductase inhibitor, finasteride, were studied in the treatment of patients with bladder outlet obstruction due to benign prostatic hyperplasia (BPH). A total of 36 patients was randomly assigned in a double-bind manner to receive either 5 mg. finasteride daily (19) or placebo (17) for 6 months. The possible relief of bladder outlet obstruction was monitored with uroflowmetry and repeated urodynamics. The mean flow rate, detrusor opening pressure, detrusor pressure at maximum flow and maximum detrusor pressure improved significantly in the patients treated with finasteride. There were no significant differences in the improvement of symptom score or peak flow rate, or in the reduction of residual urine between the finasteride and placebo groups. The treatment resulted in 30% average decrease in prostatic size and 46% decrease in prostate specific antigen concentration. The efficacy of finasteride in relief of bladder outlet obstruction caused by BPH seems to be of the same degree as that achieved by chemical castration therapy but without any significant side effects. There were wide variations among BPH patient response to finasteride treatment. Further studies are needed to define the responders who benefit from this treatment.

5-alpha Reductase Inhibitors↗
PubMed1996

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 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 > or = 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 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.

Adult↗
PubMed2006

Participation of endogenous endothelin and ETA receptor in premicturition contractions in rats with bladder outlet obstruction.

A relationship between endogenous endothelins and bladder overactivity has recently been suggested, but the related endothelin receptor subtype has not been identified. Here, to evaluate the involvement of endothelin-1 and its receptors in bladder overactivity, we investigated endothelin-1 levels and the expression of its receptors in the bladder of rats with bladder outlet obstruction (BOO), a model for bladder overactivity. We also investigated the effects of a selective endothelin ET(A) receptor antagonist, (E)-N-[6-methoxy-5-(2-methoxyphenoxy)[2,2'-bipyrimidin]-4-yl]-2-phenylethenesulfonamide monopotassium salt (YM598), on bladder functions in conscious BOO rats. Partial obstruction of the urethra led to a progressive increase in bladder weight from weeks 1 to 6. Binding assays performed using plasma membranes prepared from these bladders to estimate endothelin receptor density from the maximum [(125)I]endothelin-1 binding showed increased endothelin receptor density (about double) at 1, 2, and 6 weeks after the operation in the BOO bladder. The densities of endothelin ET(A) receptors in the bladder of sham-operated and BOO rats at 2 weeks after operation were about 3.5 and 5 times those of endothelin ET(B) receptors respectively. Furthermore, the endothelin-1 level was also increased in the BOO bladder. Two weeks after operation, BOO rats showed an increase in maximum bladder capacity and micturition volume and the generation of premicturition contractions. The frequency of premicturition contractions was dose-dependently reduced by YM598 (0.1-3 mg/kg, i.v.) without any effect on other voiding parameters in BOO rats. These data suggest that endothelin-1 and endothelin ET(A) receptors might be involved in the generation of premicturition contractions in BOO rats, and that endothelin ET(A) receptor antagonists such as YM598 may have ameliorating effects in patients with bladder overactivity associated with BOO.

Animals↗
PubMed2003

A randomized trial comparing holmium laser enucleation of the prostate with transurethral resection of the prostate for the treatment of bladder outlet obstruction secondary to benign prostatic hyperplasia in large glands (40 to 200 grams).

PURPOSE: Holmium laser enucleation of the prostate (HoLEP) is a surgical treatment for bladder outlet obstruction secondary to benign prostatic hyperplasia. HoLEP is a transurethral procedure that uses the holmium laser fiber (wavelength 2,140 nm) to dissect whole prostatic lobes off of the surgical capsule in retrograde fashion, while maintaining excellent hemostasis. The lobes are removed from the bladder by a purpose built transurethral morcellator, which means that large volume prostates can be enucleated endoscopically. We compared this procedure with transurethral prostate resection (TURP) in a randomized trial by evaluating outcomes in patients with a prostate volume of 40 to 200 ml on transrectal ultrasound. MATERIALS AND METHODS: A total of 61 patients with urodynamically proved bladder outlet obstruction secondary to benign prostatic hyperplasia were randomized to TURP or HoLEP. Perioperative parameters recorded included resectoscope, laser, electrocautery, morcellation and catheter time, hospital stay, bladder irrigation, volume blood transfusion the rate and resected tissue weight. Patients were followed 1, 3, 6 and 12 months postoperatively with peak urinary flow rate measurement and quality of life and American Urological Association symptom scores. Patients also underwent urodynamic assessment at 6 months with measurement of peak detrusor pressure at maximal flow, post-void residual volume and prostate volume by transrectal ultrasound. Continence, potency and all adverse events were recorded at each visit. RESULTS: HoLEP was superior to TURP in terms of mean catheter time (17.7 +/- 0.7 vs 44.9 +/- 10 hours) and hospital stay (27.6 +/- 2.7 vs 49.9 +/- 5.6 hours) but it required more time to perform (62.1 +/- 5.9 vs 33.1 +/- 3.7 minutes). More prostate tissue was removed in the HoLEP group (40.4 +/- 5.7 vs 24.7 +/- 3.4 gm). HoLEP was also superior to TURP in terms of relieving urodynamic obstruction at 6 months of followup (postoperative detrusor pressure at maximum flow 20.8 +/- 2.8 vs 40.7 +/- 2.7 cm H2O). HoLEP and TURP led to significant improvements in peak flow rates, symptom scores and quality of life scores compared with baseline and there was no significant difference between the 2 procedures with respect to these parameters at 12 months. Fewer adverse events were recorded in the HoLEP group. CONCLUSIONS: HoLEP is superior to TURP for relieving bladder outlet obstruction in men with benign prostatic hyperplasia. It allows more rapid catheter removal and hospital discharge. It requires more time to perform than TURP but more prostate tissue is removed, resulting in similar efficiency in tissue retrieval. HoLEP is equivalent to TURP in relieving men of lower urinary tract symptoms and in improving peak urinary flow rates at 12 months of followup.

Aged↗
PubMed2004

Smooth muscle hypertrophy following partial bladder outlet obstruction is associated with overexpression of non-muscle caldesmon.

Partial bladder outlet obstruction (PBOO) induces remodeling of urinary bladder smooth muscle (detrusor). We demonstrate an increase in bladder wall mass, muscle bundle size, and a threefold increase in the cross-sectional area of detrusor myocytes following PBOO in male New Zealand White rabbits compared to that of controls. Some bladders with detrusor hypertrophy function close to normal (compensated), whereas others were dysfunctional (decompensated), showing high intravesical pressure, large residual urine volume, and voiding difficulty. We analyzed the expression of smooth muscle-specific caldesmon (h-CaD) and non-muscle (l-CaD) by Western blotting, RT-PCR, and real-time PCR. The expression of l-CaD is increased significantly at the mRNA and protein levels in the decompensated bladders compared to that of normal and compensated bladders. The CaD was also co-localized with myosin containing cytoplasmic fibrils in cells dissociated from obstructed bladders and cultured overnight. Our data show that the inability of decompensated bladders to empty, despite detrusor hypertrophy, is associated with an overexpression of l-CaD. The level of l-CaD overexpression might be a useful marker to estimate the degree of detrusor remodeling and contractile dysfunction in PBOO.

Animals↗
PubMed1994

Evidence of possible carcinogenesis during conformational changes in bladder mucosa induced by bladder outlet obstruction.

Fourier transform infrared spectroscopy with attenuated total reflectance technique was applied to determine the mucosa on the surface of the rabbit urinary bladder wall before and after obstruction. Several abnormal spectra related to the hydrogen bonding in nucleic acids of protein, previously found in the colon malignant tissues, appeared in the infrared spectra of the obstructed bladder mucosa, which could not be found in normal bladder mucosa. Urinary bladder outlet obstruction seemed to induce carcinogenesis in the obstructed bladder mucosa by forming several infrared spectral abnormalities.

Animals↗
PubMed1997

Partial bladder outlet obstruction in the fetal rabbit.

PURPOSE: We developed and tested an animal model of bladder dysfunction due to posterior urethral valves using partial outlet obstruction of the fetal rabbit bladder. MATERIALS AND METHODS: Partial bladder outlet obstruction of fetal rabbit bladders was created on day 23 of gestation. Of the litter of 8 to 10 fetuses half was obstructed and the remainder served as controls. The doe and fetuses were sacrificed on day 30 of gestation (full term 31 to 32 days) and the fetal bladders were removed. Bladders that had doubled in weight from the average bladder weight of the control littermates were deemed sufficiently obstructed. Hematoxylin and eosin staining was performed and bladder strip response to 32 Hz. field stimulation, 200 microM. bethanechol and 200 mM. potassium chloride was measured. RESULTS: Average body weight did not differ between the control and obstructed fetuses, indicating that surgery did not hinder fetal development. Hematoxylin and eosin staining confirmed smooth muscle cell hypertrophy and increased connective tissue in the obstructed bladders. Obstructed bladder strips responded significantly less to field stimulation, and significantly more to bethanechol and potassium chloride (mean plus or minus standard deviation 5.18 +/- 1.52, 6.29 +/- 1.3 and 10.15 +/- 2.18 x force per/100 mg. tissue, respectively)than control bladder strips (9.0 +/- 1.19, 3.5 +/- 0.46 and 6.16 +/- 1.33 x force per/100 mg. tissue, respectively) suggesting that denervation supersensitivity may have resulted from obstruction. CONCLUSIONS: Partial outlet obstruction of the fetal rabbit bladder results in bladder hypertrophy and dysfunction but these changes are markedly different from those in the adult rabbit. Since rabbit fetal development is delayed compared to human fetal development, this model can be used to assess the consequences of posterior urethral valves.

Animals↗
PubMed1992

Studies on experimental bladder outlet obstruction in the cat: long-term functional effects.

Experimental bladder outlet obstruction in cats induces a significant increase in the in vivo leakage pressure. The effects of obstruction on the detrusor function were analyzed, using control, 3, 6 and 12 month obstructed cats. The in vivo leakage pressures were substantially increased in all obstructed groups. From a previous study on the short-term effects of obstruction in the cat; although there was an immediate increase in pressure, there were no significant differences between control bladders and two week obstructed bladders in: bladder weight, peak pressure response to field stimulation and bethanechol, and emptying of the in vitro whole bladder model. In this current study, although there was no direct relationship between duration of obstruction and severity of the impaired pharmacological response of the isolated whole bladder, there was a direct relationship between the magnitude of the increase in bladder weight, leakage pressure, and impaired functional response of the in vitro whole bladder. In this regard the cats were separated into four groups: controls and shams (average bladder weight 2.95 gm.), obstructed group 1 with bladder weights less than 6.0 gm. obstructed group 2 with bladder weights between 6 and 10 gm., and obstructed group 3 with bladder weights greater than 10 gm. The results can be summarized as follows: A) In vivo leakage pressures were significantly increased in all obstructed groups, and progressively higher in proportion to the bladder weights. B) Bladder capacity significantly increased in all, being greatest in obstructed group 3. C) The magnitude of the response to field stimulation of obstructed groups 1 and 2 were significantly greater than the response of control bladders at virtually all frequencies. The frequency response curve of obstructed group 3 was similar to control. D) The ability of the bladder to empty in response to field stimulation was significantly reduced in all obstructed groups. The magnitude of the decrease was proportional to the increase in bladder weight. E) There were no differences between control and obstructed bladders in the pressure response to bethanechol or KCl; the ability of both bethanechol and KCl to empty the bladder was reduced in the obstructed groups. In general, the presence of bladder enlargement was accompanied by significant alterations in the ability of the in vitro bladder to empty in response to field stimulation, bethanechol, and KCl.(ABSTRACT TRUNCATED AT 400 WORDS)

Animals↗
PubMed2006

Smooth muscle trans-membrane sarcoglycan complex in partial bladder outlet obstruction.

The urinary bladder experiences both distension and contraction as a part of the normal filling and emptying cycle. To empty properly, tension generated intracellularly in a smooth muscle cell must be smoothly and efficiently transferred across its sarcolemma to the basement membrane, which mediates its binding to both the extracellular matrix and to other cells. As a consequence of urethral obstruction, the bladder cannot generate appropriate force to contract the organ, thereby leading to inefficient emptying and associated sequelae. In this study, an animal model of urethral obstruction was utilized to study the membrane-associated structures that transfer tension across the sarcolemma of bladder smooth muscle cells. Immunohistochemical localization of key components of the smooth muscle tension transfer apparatus (TTA) was performed utilizing specific antibodies against:(1) the alpha-chains of type IV collagen, a basement membrane component, and (2) beta-sarcoglycan, an integral membrane protein that is a participant in the physical linkage between the cytoskeleton and the basement membrane. We demonstrate, in obstructed animals, that there is a pronounced disruption of the TTA with a physical displacement of these two components that can be demonstrated at the level of the light microscope using scanning confocal microscopy. Electron microscopy further demonstrates significant increases in the size of the junctional plaques between smooth muscle cells.

Animals↗
PubMed2000

Urolume stent placement for the treatment of postbrachytherapy bladder outlet obstruction.

OBJECTIVES: Transurethral resection (TURP) or incision of the prostate is generally not effective for treating bladder outlet obstruction after transperineal brachytherapy for prostate cancer. Furthermore, TURP could compromise full-dose effective radiation delivery to the prostate. We analyzed the efficacy of the UroLume stent in treating the urinary outflow obstruction in such patients. METHODS: Five patients who had undergone brachytherapy (3 with (192)Ir high-dose radiation and 2 with (125)I) subsequently developed one or more episodes of urinary retention 2 weeks to 4 years after treatment. The patients failed or could not tolerate alpha-blockers or clean intermittent catheterization. Three patients subsequently underwent urethral dilation/optical internal urethrotomy for strictures, and 1 patient underwent suprapubic tube placement. Following the failure of these interventions, each of these patients had a UroLume stent placement. A single UroLume stent (2 cm in 3 patients and 2.5 cm in 2 patients) was placed under local/spinal anesthesia. RESULTS: All patients were able to void spontaneously immediately after stent placement. Of the patients with previous urethral strictures, 1 remained continent and 1 had persistent incontinence. Neither of the patients with early postbrachytherapy retention developed incontinence after stent placement. The main complaints following stent placement were referred pain to the head of the penis and dysuria. Stent-related symptoms necessitated stent removal in 2 of 5 patients, 4 to 6 weeks after placement. CONCLUSIONS: The UroLume stent can be used as an alternative form of therapy for managing postbrachytherapy bladder outlet obstruction. The treatment is easily reversible by removing the stent when obstruction resolves.

Aged↗
PubMed2006

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.

Humans↗