Bladder Neck Contractures Stabilize After Placement of the Artificial Urinary Sphincter

PURPOSE

For male cancer survivors, the combination of stress urinary incontinence and recurrent bladder neck contracture presents a management dilemma with poor consensus. Our objective was to assess the impact of artificial urinary sphincter placement on bladder neck contracture recurrence among prostate cancer survivors with stress urinary incontinence and bladder neck contracture.

MATERIALS AND METHODS

Men electing artificial urinary sphincter placement at our institution undergo synchronous bladder neck contracture treatment if indicated. An institutional database was queried for men with stress urinary incontinence and ≥1 intervention for bladder neck contracture. Records were divided according to whether an artificial urinary sphincter was ever placed. The impact of artificial urinary sphincter placement on bladder neck contracture recurrence was assessed using a multivariable conditional survival analysis, with survival defined as the recurrence-free interval following bladder neck contracture intervention. The proportional hazards assumption was assessed on the basis of Schoenfeld residuals.

RESULTS

The analytic cohort consisted of 118 in the artificial urinary sphincter group and 88 in the non-artificial urinary sphincter group. Patients in both groups underwent a median of 2 (range 1-8) bladder neck contracture interventions over the entire course of their care, encompassing 445 total bladder neck contracture interventions. The artificial urinary sphincter group was on average 2.6 years younger (P = .02) and had a higher pack-year smoking history (P < .01). The presence of an artificial urinary sphincter was associated with a 61% lower bladder neck contracture re-intervention rate (HR 0.39, P < .01, CI 0.30-0.50) at any time when accounting for number of prior bladder neck contracture interventions and bladder neck contracture risk factors.

CONCLUSIONS

Artificial urinary sphincter placement is associated with a lower rate of bladder neck contracture re-intervention. Artificial urinary sphincter placement should not be delayed or avoided due to the presence of bladder neck contracture.

Could CA 19-9 be a useful biomarker in the diagnosis, prognosis, and prediction of adequate relief in lower urinary tract obstructions?

INTRODUCTION

posterior urethral valves represent an important cause of childhood chronic kidney disease. The identification of biomarkers that indicate early kidney damage and even adequate clearance could reduce how many patients head towards kidney failure.

OBJECTIVE

this study evaluated how this easy-analysis biomarker (CA 19-9) could help identifying potential renal damage and adequate clearance in obstructive uropathies.

METHODS

46 female Wistar rats were divided into 5 groups, with different patterns of partial urinary tract obstruction: group control; group OIV: infravesical obstruction; group OIVd: infravesical obstruction with reversion, obstruction relief 7 postoperative days later; group OUu: unilateral ureteral obstruction; group OUb: bilateral ureteral obstruction. The CA 19-9s performance was compared to another biomarker: Ngal. Determination of basal CA 19-9 and Ngal in urine and blood and serum creatinine levels was performed in the rats prior to surgery (T0) and after 14 days (T1). Group OIVd underwent intermediate (Ti) collection before clearance.

RESULTS

the urinary concentration of CA 19-9 increased in groups OIV, OIVd and OUb; elevation at T1 and Ti, reached statistical significance compared to the T0 value (p<0,05). Changes in urinary CA 19-9 were more expressive in infravesical obstruction groups (AUC 0.81). Obstruction relief in group OIVd promoted significant urinary CA 19-9 reduction (p<0,05) in the final evaluation.

CONCLUSIONS

CA 19-9 urinary concentration increased in partial urinary tract obstruction. Its best performance was in the bladder neck obstruction group, in which the elevation was detected early (6 days after infravesical obstruction) and the CA19-9 urinary concentration declined after clearance.

Use of the penile cuff test to diagnose bladder outlet obstruction: A systematic review and meta-analysis

PURPOSE

Among noninvasive modalities for assessing bladder outlet obstruction (BOO), the penile cuff test (PCT) is the most used in clinical practice. The purpose of this review was to evaluate the performance of PCT in diagnosing and managing BOO.

MATERIALS AND METHODS

PubMed, Scopus, CINAHL, Embase, Cochrane Library, and Web of Science were searched for studies investigating use of PCT for BOO. Studies evaluating diagnostic parameters, inter-observer agreements, or treatment outcomes using PCT were included. The Preferred Reporting Items for Systematic Reviews and Meta-Analyses protocol was followed (PROSPERO ID: CRD42022300047). A proportional meta-analysis was done for diagnostic accuracy proportions. The Egger's and the Begg-Mazumdar rank-correlation tests were used to assess publication bias. Risk of bias was assessed using the Gradings of Recommendations, Assessment, Development, and Evaluations (GRADE) criteria.

RESULTS

Of the 272 articles retrieved, 17 were included in qualitative synthesis and meta-analysis was performed on five studies (comprising 448 patients). Two studies evaluating inter-observer agreement demonstrated 95% agreement and five studies evaluating procedures reported a 66%-80% surgical success rate on obstructed patients using PCT. From the proportional meta-analysis, the sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) were 0.85 (95% CI 0.71-0.95) 0.78 (95% CI 0.67-0.87), 0.74 (95% CI 0.52-0.91), and 0.87 (95% CI 0.73-0.96), respectively. Publication bias was noted for PPV but not for sensitivity, specificity, or NPV. Based on the GRADE criteria, there were two low, six moderate, and nine high-quality studies.

CONCLUSIONS

PCT performs sufficiently in diagnosing and managing BOO. However, due to variability in obstruction criteria assessment, more studies comparing diagnostic criteria are warranted.

Urodynamic autonomic bladder dysfunction in women with complex chronic pelvic pain is associated with small fiber polyneuropathy

AIMS

Small fiber neuropathy/polyneuropathy (SFN) has been found to be present in 64% of complex (refractory or multisystem) chronic pelvic pain (CPP) patients. The small fiber dysfunction seen in SFN can negatively impact autonomic control of micturition in addition to pain. This study investigated the clinical association of autonomic dysfunction (detrusor underactivity and primary bladder neck obstruction [BNO]) on video urodynamics (VUDS) with SFN in patients with CPP.

METHODS

This was a retrospective observational study, querying data from patients with complex CPP. Inclusion criteria were: the presence of complex (refractory or multisystem) CPP, and completion of both (1) subspecialty autonomic neurology evaluation for SFN and (2) high-quality VUDS performed according to ICS standards. Autonomic bladder dysfunction (BNO or detrusor underactivity) on VUDS was compared to the presence of SFN.

RESULTS

Thirty-two female patients with complex CPP met criteria. Of the 32, 23 (72%) were found to have SFN. Patient with autonomic bladder dysfunction (BNO or detrusor underactivity) were more likely to have SFN (OR = 9.5 [95% CI: 1.641, 55.00], p = 0.007). Post-void residual volume was higher in the SFN group (p = 0.011 [95% CI: 13.12, 94.0]) and symptoms of urge urinary incontinence were more likely to be present (p = 0.000 [95% CI: -3.4, -1.25]).

CONCLUSIONS

Patients with complex CPP with autonomic bladder dysfunction are more likely to have SFN. This suggests patients with complex CPP should be considered for diagnosis and treatment of SFN, particularly if BNO or detrusor underactivity is noted on VUDS evaluation.

One-Year Results for the ROBUST III Randomized Controlled Trial Evaluating the Optilume® Drug-Coated Balloon for Anterior Urethral Strictures

PURPOSE

The Optilume® drug-coated balloon (DCB) is a urethral dilation balloon with a paclitaxel coating that combines mechanical dilation for immediate symptomatic relief with local drug delivery to maintain urethral patency. The ROBUST III study is a randomized, single-blind trial evaluating the safety and efficacy of the Optilume DCB against endoscopic management of recurrent anterior urethral strictures.

MATERIALS AND METHODS

Eligible patients were adult males with anterior strictures ≤12Fr in diameter and ≤3 cm in length, at least 2 prior endoscopic treatments, International Prostate Symptom Score ≥11 and maximum flow rate <15 ml per second. A total of 127 subjects were enrolled at 22 sites. The primary study end point was anatomical success (≥14Fr by cystoscopy or calibration) at 6 months. Key secondary end points included freedom from repeat treatment, International Prostatic Symptom Score and peak flow rate. The primary safety end point included freedom from serious device- or procedure-related complications.

RESULTS

Baseline characteristics were similar between groups, with subjects having an average of 3.6 prior treatments and average length of 1.7 cm. Anatomical success for Optilume DCB was significantly higher than control at 6 months (75% vs 27%, p <0.001). Freedom from repeat intervention was significantly higher in the Optilume DCB arm. Immediate symptom and urinary flow rate improvement was significant in both groups, with the benefit being more durable in the Optilume DCB group. The most frequent adverse events included urinary tract infection, post-procedural hematuria and dysuria.

CONCLUSIONS

The results of this randomized controlled trial support that Optilume is safe and superior to standard direct vision internal urethrotomy/dilation for the treatment of recurrent anterior urethral strictures <3 cm in length. The Optilume DCB may serve as an important alternative for men who have had an unsuccessful direct vision internal urethrotomy/dilation but want to avoid or delay urethroplasty.

Artifacts and abnormal findings may limit the use of asymptomatic volunteers as controls for studies of multichannel urodynamics

BACKGROUND

Multichannel urodynamics is the gold standard for the evaluation of lower urinary tract symptoms (LUTS). When performing studies to validate new adjuncts to urodynamic testing with control patients undergoing urodynamic investigation, there is difficulty in the interpretation of urodynamic results in the asymptomatic patient due to artifacts and the invasive nature of the procedure. The purpose of this investigation was to examine urodynamics in asymptomatic volunteers in order to better understand the role of control participants in urodynamic research studies.

METHODS

Asymptomatic volunteers with no LUTS were recruited to undergo standard urodynamic testing as a comparison group in a study evaluating novel urodynamic techniques. To be eligible, participants had to report no LUTS, score ≤1 on all symptom questions of the International Consultation on Incontinence Questionnaire Overactive Bladder Module (ICIq-OAB) survey, have no medical conditions or to undergo any medications that affect bladder function. The urodynamics was done according to ICS standards. All tracings were evaluated by an expert neuro-urologist. Data were analyzed categorically for the presence or absence of low compliance (<30 mL/cmH20), detrusor overactivity, bladder outlet obstruction (Bladder Outlet Obstruction Index [BOOI]>40), weak contractility (bladder contractility index [BCI]<100), straining to void, poorly sustained detrusor contraction, uncoordinated EMG activity, and intermittent flow.

RESULTS

A total of 24 participants completed the study including 10 men and 14 women. All participants had at least 1 urodynamic abnormality/artifact with an average of 4.43±1.28 abnormalities/participant. The most common abnormalities included uncoordinated electromyography (EMG) activity (87.50%), straining to void (79.17%), and intermittent flow (70.83%). There were no significant differences for sex, age, Body Mass Index.

CONCLUSIONS

This study demonstrated that healthy, asymptomatic volunteers have high rates of abnormal urodynamic findings, suggesting that asymptomatic participants are not the ideal controls in research studies that involve urodynamic testing.

A narrative review of the management of benign prostatic hyperplasia in patients undergoing penile prosthesis surgery

Penile prosthesis surgery is an effective and durable treatment modality for patients who have failed conservative management for erectile dysfunction (ED). Thorough patient counseling and appropriate preoperative workup lay the foundation for a successful outcome. While the risk of infection of penile prosthesis is rare, it is a dreaded complication with dire consequences. The goal of the prosthetic surgeon is to minimize the risk of preventable complications. Given the common prevalence of benign prostatic hyperplasia (BPH) in this patient population, it is essential that providers are familiar with the implications and nuances of managing both conditions in order to maximize the chances of a favorable result. Due to the relatively infrequent nature of complications associated with the management of BPH in the setting of a penile prosthesis, literature regarding this topic is scarce. In this narrative review we present our own case series illustrating some of the most common scenarios that a prosthetic surgeon may encounter. We have included our suggestions for management in these difficult situations based on our clinical experience. In the following review we have highlighted the importance of identifying and treating BPH in penile implant candidates to reduce postoperative morbidity and to offer critical insights into managing BPH-related complications this population.

The effect of proliferative hypertrophic scars on determining treatment options for preventing recurrence of vesicourethral anastomotic stenosis after radical prostatectomy: a single-center cross-sectional study

BACKGROUND

Vesicourethral anastomotic stenosis (VUAS) following retropubic radical prostatectomy (RRP) significantly worsens quality of life.

OBJECTIVES

To investigate the relationship between proliferative hypertrophic scar formation and VUAS, and predict more appropriate surgical intervention for preventing recurrent VUAS.

DESIGN AND SETTING

Retrospective cross-sectional single-center study on data covering January 2009 to December 2019.

METHODS

Among 573 male patients who underwent RRP due to prostate cancer, 80 with VUAS were included. They were divided into two groups according to VUAS treatment method: dilatation using Amplatz renal dilators (39 patients); or endoscopic bladder neck incision/resection (41 patients). The Vancouver scar scale (VSS) was used to evaluate the characteristics of scars that occurred for any reason before development of VUAS.

RESULTS

Over a median follow-up of 72 months (range 12-105) after RRP, 17 patients (21.3%) had recurrence of VUAS. Although the treatment success rates were similar (79.5% versus 78.0%; P = 0.875), receiver operating characteristic (ROC) curve analysis indicated that dilatation using Amplatz dilators rather than endoscopic bladder neck incision/resection in patients with VSS scores 4, 5 and 6 may significantly reduce VUAS recurrence. A strong positive relationship was observed between VSS and total number of VUAS occurrences (r: 0.689; P < 0.001). VSS score (odds ratio, OR: 5.380; P < 0.001) and time until occurrence of VUAS (OR: 1.628; P = 0.008) were the most significant predictors for VUAS recurrence.

CONCLUSIONS

VSS score can be used as a prediction tool for choosing more appropriate surgical intervention, for preventing recurrent VUAS.

Minimally Invasive Radical Prostatectomy after Previous Bladder Outlet Surgery: A Systematic Review and Pooled Analysis of Comparative Studies

PURPOSE

Prostate cancer surgery after previous bladder outlet surgery of benign prostatic hyperplasia is an uncommon yet challenging scenario. We performed a systematic review and pooled analysis of comparative studies on laparoscopic and robotic minimally invasive radical prostatectomy after bladder outlet surgery.

MATERIALS AND METHODS

We searched the literature on PubMed®, Embase® and Web of Science™ up to February 2019 according to the PRISMA (Preferred Reporting Items for Systematic Review and Meta-Analyses) statement to identify eligible studies. Surgical, oncologic and functional outcomes in patients who underwent minimally invasive radical prostatectomy after bladder outlet surgery were compared to those without a history of bladder outlet surgery. Sensitivity analysis was done according to surgical technique (laparoscopic or robotic). RevMan 5.3 was used for statistical analysis.

RESULTS

A total of 12 comparative studies were included in analysis. Patients who underwent minimally invasive radical prostatectomy after bladder outlet surgery were older (p ≤0.00001) and had a smaller prostate (p = 0.04) and lower prostate specific antigen (p = 0.003). The previous bladder outlet surgery group had lower odds of nerve sparing procedures, longer operative time, a higher rate of bladder neck reconstruction (each p <0.0001) and longer catheter time (p = 0.03). They were at higher risk for intraoperative (p = 0.001), overall (p <0.00001) and major complications (p = 0.0008), a higher positive surgical margin rate (p = 0.0005) and biochemical recurrence (p = 0.05). Moreover, potency (p = 0.03) and continence recovery (p = 0.007) at 12 months were lower in men with previous bladder outlet surgery. Robotic surgery seemed to offer better outcomes than laparoscopy.

CONCLUSIONS

Minimally invasive radical prostatectomy after previous bladder outlet surgery represents a challenging surgical task with a higher risk of complications, and higher odds of worse functional and oncologic outcomes. Patients should be aware of these drawbacks and these factors should be considered during patient counseling. When surgery is pursued, robot-assisted radical prostatectomy should be preferred over laparoscopic radical prostatectomy since it can offer superior outcomes. The overall literature on this topic is of low quality and further efforts should be made to obtain higher levels of evidence.

Suture causing urethral meatus stricture: A novel animal model of partial bladder outlet obstruction

AIMS

Open surgery is the most commonly used methodological approach for generating a partial bladder outlet obstruction (pBOO) animal model. Surgical suturing closing a part of the urethral meatus induces comparable pathophysiological changes in bladder and renal functions, but the optimum degree of obstruction that closely mimics the clinical pathology of pBOO has not been elucidated. We investigated the optimum obstruction level by performing a comprehensive time-dependent analysis of the stability and reliability of this novel animal model.

METHODS

Six- to eight-week-old female BALB/c mice were divided into three groups according to the degree of urethral meatus stricture (UMS). Non-operated mice served as controls, and a pBOO model generated using the traditional method served as a positive control. A cystometric evaluation and long-term studies were performed to evaluate the validity and reliability of this novel animal model. An additional 35 mice were used to investigate the protein expression levels and histopathological features 24 h and 14 days postoperatively, respectively.

RESULTS

The characteristic cystometry features in the UMS group revealed increased changes in pressure-related parameters compared with the control. The 1/3 UMS model is an optional pBOO animal model because the cystometric evaluation and histopathological studies revealed a striking resemblance between the 1/3 UMS model and the model generated using the traditional open-surgery method.

CONCLUSIONS

The minimally invasive UMS model required less time and produced minimal alterations in pathophysiologically relevant processes compared with the traditional surgery model. Suturing to cause UMS produced effective and repeatable patterns in bladder function investigations in mice.

Bilateral Hydroureteronephrosis with a Hypertrophied, Trabeculated Urinary Bladder

Bilateral hydroureteronephrosis involves the dilatation of the renal pelvis, calyces and ureter; it develops secondary to urinary tract obstruction and leads to a build-up of back pressure in the urinary tract, and it may lead to impairment of renal function and ultimately culminate in renal failure. Although clinically silent in most cases, it can be diagnosed as an incidental finding during evaluation of an unrelated cause. In a minority of patients, it presents with signs and symptoms. Renal calculus is the most common cause, but there are multiple non-calculus aetiologies, and they depend on age and sex. Pelviureteric junction obstruction, benign prostatic hypertrophy, urethral stricture, neurogenic bladder, retroperitoneal mass and bladder outlet obstruction are some of the frequent causes of hydroureteronephrosis in adults. The incidence of non-calculus hydronephrosis is more common in males than in females. Ultrasonography is the most important baseline investigation in the evaluation of patients with hydronephrosis. Here, we report a rarely seen case of bilateral hydroureteronephrosis associated with a hypertrophied, trabeculated bladder in an adult male cadaver, suspected to be due to a primary bladder neck obstruction, and analyse its various other causes, clinical presentations and outcomes.

Postoperative Urinary Retention is an Independent Predictor of Short-Term and Long-Term Future Bladder Outlet Procedure in Men

PURPOSE

Postoperative urinary retention is a common complication across surgical specialties. To our knowledge no literature to date has examined postoperative urinary retention as a predictor of long-term receipt of surgery for bladder outlet obstruction.

MATERIALS AND METHODS

We retrospectively reviewed the records of inpatients who underwent nonurological surgery in California between 2008 and 2010. Postoperative urinary retention during the index admission was identified, as was receipt of a bladder outlet procedure (transurethral prostate resection, prostate photoselective vaporization or suprapubic prostatectomy) at a subsequent encounter. Patients were matched using propensity scoring of demographics, comorbidities and surgery type. Adjusted Kaplan-Meier analysis was performed to determine the cumulative incidence of subsequent bladder outlet procedures by patient group, including group 1-age 60 years or greater and postoperative urinary retention, group 2-age 60 years or greater and no postoperative urinary retention, group 3-age less than 60 years and postoperative urinary retention, and group 4-age less than 60 years and no postoperative urinary retention.

RESULTS

Of 769,141 eligible male patients postoperative urinary retention developed in 8,051 (1.1%). Following hospital discharge 1,855 patients (0.24%) underwent a bladder outlet procedure. Those treated with a bladder outlet procedure were significantly more likely to have experienced postoperative urinary retention during the index admission (6.3% vs 1.0%, p <0.001). On matched analysis the bladder outlet procedure rate at 3 years was 7.1%, 2.2%, 0.8% and 0.0% in groups 1, 2, 3 and 4, respectively.

CONCLUSIONS

In men 60 years old or older postoperative urinary retention identified those with an increased incidence of bladder outlet procedures within 3 years. Men younger than 60 years had a low rate of subsequent bladder outlet procedures regardless of a postoperative urinary retention diagnosis.

Aquablation of the Prostate for Symptomatic Benign Prostatic Hyperplasia: 1-Year Results

PURPOSE

We sought to establish the safety and effectiveness of aquablation, a novel, image guided, robotic assisted, water jet tissue ablation technology, for the treatment of benign prostatic hyperplasia.

MATERIALS AND METHODS

We performed a prospective, single arm, multicenter trial at a total of 3 centers in Australia and New Zealand with 1-year followup. Participants were men 50 to 80 years old with moderate to severe lower urinary tract symptoms as determined by urodynamics. All patients underwent aquablation under image guidance. Primary end points included procedural and perioperative safety. The main clinical end point was the change from baseline in I-PSS (International Prostate Symptom Score). Other secondary end points included uroflow measures, prostate volume on transrectal ultrasound and detrusor pressure. Detrusor pressure at maximum flow was only measured at 6 months.

RESULTS

A total of 21 men underwent aquablation at a mean age of 69.7 years (range 62 to 78). Prostate volume was 57.2 ml (range 30 to 102). Procedural duration averaged 38 minutes with a mean aquablation treatment time of 5 minutes. All but 1 subject were catheterized for 1 day only and 19 of 21 were discharged home the day after the procedure. Detrusor pressure at maximum flow decreased from 65 cm H₂O at baseline to 39 cm H₂O at 6 months (p <0.0027). Prostate volume decreased from 57 ml at baseline to 35 ml (p <0.0001). Mean I-PSS score improved from 23.0 at baseline to 6.8 at 12 months (p <0.0001) and maximum urinary flow increased from 8.7 to 18.3 ml per second (p <0.0001). There were no important perioperative adverse events. No urinary incontinence developed and sexual function was preserved postoperatively.

CONCLUSIONS

This phase II study provides early evidence to support the safety and effectiveness of aquablation for symptomatic benign prostatic hyperplasia.

Severe lower urinary tract symptoms due to anteriorly located midline prostatic cyst arising from the bladder neck in a young male: case report

CONTEXT:

Prostatic cysts are uncommon. These cysts are usually asymptomatic and are diagnosed incidentally during ultrasonographic examination. On rare occasions, they may cause drastic symptoms.

CASE REPORT:

We report on a case of severely symptomatic anteriorly located prostatic cyst arising from the bladder neck in a 30-year-old man presenting with lower urinary tract symptoms, without clinical evidence of benign prostatic hyperplasia. Transrectal ultrasonography (TRUS), computed tomography (CT) and cystourethroscopy demonstrated a projecting prostatic cyst that occupied the bladder neck at the precise twelve o'clock position. It was acting as a ball-valve, such that it obstructed the bladder outlet. Transurethral unroofing of the cyst was performed and the patient's obstructive symptoms were successfully resolved. Histopathological examination indicated a retention cyst.

CONCLUSIONS:

It should be borne in mind that midline prostate cysts can be a reason for bladder outlet obstruction in a young male. Such patients may have tremendous improvement in symptoms through transurethral unroofing of the cyst wall.

Inhibition of HIF Reduces Bladder Hypertrophy and Improves Bladder Function in Murine Model of Partial Bladder Outlet Obstruction

PURPOSE

Posterior urethral valves are the most common cause of partial bladder outlet obstruction in the pediatric population. However, to our knowledge the etiology and the detailed mechanisms underlying pathological changes in the bladder following partial bladder outlet obstruction remain to be elucidated. Recent findings suggest that hypoxia and associated up-regulation of HIFs (hypoxia-inducible factors) have a key role in partial bladder outlet obstruction induced pathology in the bladder. We examined the effects of pharmacological inhibition of HIF pathways by 17-DMAG (17-(dimethylaminoethylamino)-17-demethoxygeldanamycin) in pathophysiological phenotypes after partial bladder outlet obstruction.

MATERIALS AND METHODS

Partial bladder outlet obstruction was surgically created in male C57BL/6J mice. The animals received oral administration of 17-DMAG or vehicle daily starting from the initiation of obstruction up to 5 days. Sham operated mice served as controls. Bladders were harvested from each group 2, 4 and 7 days postoperatively, and analyzed for histological and biochemical changes. Bladder function was assessed by in vitro muscle contractility recordings.

RESULTS

Partial bladder outlet obstruction caused a significant increase in the bladder mass accompanying enhanced collagen deposition in the bladder wall while 17-DMAG treatment suppressed those increases. Treatment with 17-DMAG attenuated the degree of up-regulation of HIFs and their target genes involving the development of tissue fibrosis in obstructed bladders. Treatment with 17-DMAG improved the decreased responses of obstructed bladder strips to electrical field stimulation and KCl.

CONCLUSIONS

In vivo 17-DMAG treatment decreased partial bladder outlet obstruction induced pathophysiological changes in the bladder. HIF pathway inhibition has a potential clinical implication for the development of novel pharmacological therapies to treat bladder pathology associated with partial bladder outlet obstruction.

The NLRP3 Inflammasome Mediates Inflammation Produced by Bladder Outlet Obstruction

PURPOSE

While bladder outlet obstruction is well established to elicit an inflammatory reaction in the bladder that leads to overactive bladder and fibrosis, little is known about the mechanism by which this is initiated. NLRs (NOD-like receptors) and the structures that they form (inflammasomes) have been identified as sensors of cellular damage, including pressure induced damage, and triggers of inflammation. Recently we identified these structures in the urothelium. In this study we assessed the role of the NLRP3 (NACHT, LRR and PYD domains-containing protein 3) inflammasome in bladder dysfunction resulting from bladder outlet obstruction.

MATERIALS AND METHODS

Bladder outlet obstruction was created in female rats by inserting a 1 mm outer diameter transurethral catheter, tying a silk ligature around the urethra and removing the catheter. Untreated and sham operated rats served as controls. Rats with bladder outlet obstruction were given vehicle (10% ethanol) or 10 mg/kg glyburide (a NLRP3 inhibitor) orally daily for 12 days. Inflammasome activity, bladder hypertrophy, inflammation and bladder function (urodynamics) were assessed.

RESULTS

Bladder outlet obstruction increased urothelial inflammasome activity, bladder hypertrophy and inflammation, and decreased voided volume. Glyburide blocked inflammasome activation, reduced hypertrophy and prevented inflammation. The decrease in voided volume was also attenuated by glyburide mechanistically as an increase in detrusor contraction duration and voiding period.

CONCLUSION

Results suggest the importance of the NLRP3 inflammasome in the induction of inflammation and bladder dysfunction secondary to bladder outlet obstruction. Arresting these processes with NLRP3 inhibitors may prove useful to treat the symptoms that they produce.

The Patient Burden of Bladder Outlet Obstruction after Prostate Cancer Treatment

PURPOSE

Bladder outlet obstruction after prostate cancer therapy imposes a significant burden on health and quality of life in men. Our objective was to describe the burden of bladder outlet obstruction after prostate cancer therapy by detailing the type of procedures performed and how often those procedures were repeated in men with recurrent bladder outlet obstruction.

MATERIALS AND METHODS

Using SEER (Surveillance, Epidemiology and End Results)-Medicare linked data from 1992 to 2007 with followup through 2009 we identified 12,676 men who underwent at least 1 bladder outlet obstruction procedure after prostate cancer therapy, including external beam radiotherapy in 3,994, brachytherapy in 1,485, brachytherapy plus external beam radiotherapy in 1,847, radical prostatectomy in 4,736, radical prostatectomy plus external beam radiotherapy in 369 and cryotherapy in 245. Histogram, incidence rates and Cox proportional hazards models with repeat events analysis were done to describe the burden of repeat bladder outlet obstruction treatments stratified by prostate cancer therapy type. We describe the type of bladder outlet obstruction surgery grouped by level of invasiveness.

RESULTS

At a median followup of 8.8 years 44.6% of men underwent 2 or more bladder outlet obstruction procedures. Compared to men who underwent radical prostatectomy those treated with brachytherapy and brachytherapy plus external beam radiotherapy were at increased adjusted risk for repeat bladder outlet obstruction treatment (HR 1.2 and 1.32, respectively, each p <0.05). After stricture incision the men treated with radical prostatectomy or radical prostatectomy plus external beam radiotherapy were most likely to undergo dilation at a rate of 34.7% to 35.0%. Stricture resection/ablation was more common after brachytherapy, external beam radiotherapy or brachytherapy plus external beam radiotherapy at a rate of 28.9% to 41.2%.

CONCLUSIONS

Almost half of the men with bladder outlet obstruction after prostate cancer therapy undergo more than 1 procedure. Furthermore men with bladder outlet obstruction after radiotherapy undergo more invasive endoscopic therapies and are at higher risk for multiple treatments than men with bladder outlet obstruction after radical prostatectomy.

Durable Results of Mitomycin C Injection with Internal Urethrotomy for Refractory Bladder Neck Contractures: Multi-institutional Experience

INTRODUCTION

We evaluated our intermediate term experience with radial urethrotomy and intralesional mitomycin C injection in patients with recurrent bladder neck contractures. Recurrent bladder neck contractures in which previous endoscopic treatment failed pose a difficult management dilemma.

METHODS

Prospectively collected data were reviewed in a retrospective manner of patients presenting with recurrent bladder neck contractures from January 2007 to June 2014. All patients had at least 1 prior failed incision of a bladder neck contracture and many had additional dilations or catheter dependence. Radial cold knife incisions of the bladder neck were performed followed by injection of 0.3 to 0.4 mg/ml mitomycin C at each incision site. All surgeons performed the incision technique and injection in a reproducible fashion.

RESULTS

A total of 40 patients underwent urethrotomy with mitomycin C injection. At a median followup of 20.5 months 30 patients (75.0%) had a stable bladder neck after 1 procedure. An additional 5 patients required 2 procedures to obtain a stable patent bladder neck (87.5%). Of the 40 patients 14 (35.0%) presented in retention on catheter drainage and all had a stable, patent bladder neck. No recurrence was detected in the original 18 patients in the pilot study with patent bladder necks. Rigorous followup revealed no long-term complications.

CONCLUSIONS

Urethrotomy with mitomycin C injection for the management of recurrent bladder neck contractures is safe and efficacious. The addition of an antifibrotic agent in conjunction with internal urethrotomy offers a definitive solution to a problem that would otherwise be managed with repeat urethral incision/dilation, catheter dependence or open bladder neck reconstruction.

A clever technique for placement of a urinary catheter over a wire

Objective:

The objective was to present a straightforward, step-by-step reproducible technique for placement of a guide-wire into any type of urethral catheter, thereby offering a means of access similar to that of a council-tip in a situation that may require a different type of catheter guided over a wire.

Materials and Methods:

Using a shielded intravenous catheter inserted into the eyelet of a urinary catheter and through the distal tip, a “counsel-tip” can be created in any size or type of catheter. Once transurethral bladder access has been achieved with a hydrophilic guide-wire, this technique will allow unrestricted use of catheters placed over a wire facilitating guided catheterization.

Results:

Urethral catheters of different types and sizes are easily advanced into the bladder with wire-guidance; catheterization is improved in the setting of difficult urethral catheterization (DUC). Cost analysis demonstrates benefit overuse of traditional council-tip catheter.

Conclusion:

Placing urinary catheters over a wire is standard practice for urologists, however, use of this technique gives the freedom of performing wire-guided catheterization in more situations than a council-tip allows. This technique facilitates successful transurethral catheterization over wire in the setting of DUC for all catheter types and styles aiding in urologic management of patients at a cost benefit to the health care system.

Activation of P2Y6 Receptors Facilitates Nonneuronal Adenosine Triphosphate and Acetylcholine Release from Urothelium with the Lamina Propria of Men with Bladder Outlet Obstruction

PURPOSE

Deregulation of purinergic bladder signaling may contribute to persistent detrusor overactivity in patients with bladder outlet obstruction. Activation of uridine diphosphate sensitive P2Y6 receptors increases voiding frequency in rats indirectly by releasing adenosine triphosphate from the urothelium. To our knowledge this mechanism has never been tested in the human bladder.

MATERIALS AND METHODS

We examined the role of the uridine diphosphate sensitive P2Y6 receptor on tetrodotoxin insensitive nonneuronal adenosine triphosphate and [(3)H]acetylcholine release from the human urothelium with the lamina propria of control organ donors and patients with benign prostatic hyperplasia.

RESULTS

The adenosine triphosphate-to-[(3)H]acetylcholine ratio was fivefold higher in mucosal urothelium/lamina propria strips from benign prostatic hyperplasia patients than control men. The selective P2Y6 receptor agonist PSB0474 (100 nM) augmented by a similar amount adenosine triphosphate and [(3)H]acetylcholine release from mucosal urothelium/lamina propria strips from both groups of individuals. The facilitatory effect of PSB0474 was prevented by MRS2578 (50 nM) and by carbenoxolone (10 μM), which block P2Y6 receptor and pannexin-1 hemichannels, respectively. Blockade of P2X3 (and/or P2X2/3) receptors with A317491 (100 nM) also attenuated release facilitation by PSB0474 in control men but not in patients with benign prostatic hyperplasia. Immunolocalization studies showed that P2Y6, P2X2 and P2X3 receptors were present in choline acetyltransferase positive urothelial cells. In contrast to P2Y6 staining, choline acetyltransferase, P2X2 and P2X3 immunoreactivity decreased in the urothelium of benign prostatic hyperplasia patients.

CONCLUSIONS

Activation of P2Y6 receptor amplifies mucosal adenosine triphosphate release underlying bladder overactivity in patients with benign prostatic hyperplasia. Therefore, we propose selective P2Y6 receptor blockade as a novel therapeutic strategy to control persistent storage symptoms in obstructed patients.

Bladder function in obstructed men - does age matter?

AIM

The high prevalence of diseases and disabilities in the elderly will therefore impose major future challenges for governments, particularly in social security, health system and social care.

METHODS

Nine hundred and seventy-one men, 40 years or older referred for low urinary tract symptoms (LUTS) evaluation who underwent full urodynamic investigation, were reviewed. Urodynamic parameters were obtained, such as Uroflowmetry, those of Filling Cystometry and those of pressure flow study (PFS).

RESULTS

Mean age was of 66.1 years old. Most the patients included in the analysis were categorized as Schafer score 2-4. Correlation analysis of uroflowmetry parameters revealed statistically significant decrease in voided volume (p = 0.013), Qmax (p = 0.023) with aging. Cystometric parameters revealed significant age-related decrease in bladder capacity (p < 0.001) and bladder compliance (p = 0.004). PFS revealed significant decrease in voiding efficiency (p = 0.029), voided volume (p < 0.001), Qave (p = 0.008) and Qmax (p = 0.048) with progressing age. Age subgroup analyses showed significant differences in voiding efficiency (KW, p = 0.032), voided volume (KW, p < 0.001) and Qave (KW, p = 0.036).

CONCLUSIONS

Age-related changes in voiding function might not be a result of impaired detrusor contractility or increased outflow obstruction, intrinsic causes must be suspected. Changes in the storage function of the bladder represent specific pathophysiological mechanisms influenced by aging.

The value of surgical release after obstructive anti-incontinence surgery: An aid for clinical decision making

AIMS

To present satisfaction rates after surgical release of obstructive anti-incontinence surgery, to look for predictive factors for outcome and to define the optimal moment to perform the surgical release.

METHODS

We reviewed the charts of 87 women at first, second, and last follow-up at a median of 2 (0.5-7), 4 (2-12), and 108 (29-156) months after surgical release. Obstruction was defined as urinary retention, straining to void after overcorrected anti-incontinence treatment or urodynamic bladder outlet obstruction. Patients' satisfaction was assessed using a 4 point Likert scale.

RESULTS

Satisfaction rates at first, second, and last follow-up were 66% (n = 54/82), 54% (n = 37/69), and 74% (n = 43/58) respectively. Postoperatively, patients complained about overactive bladder (OAB) symptoms in 37% (n = 30/81) and SUI in 28% (n = 23/81) at first follow-up and in 41% (n = 28/68) and 27% (n = 18/68) at second follow-up for OAB symptoms and stress urinary incontinence (SUI) respectively. When surgical release was performed more than 180 days after original surgery, less SUI (P = 0.008) was reported. When performed within 70 days in patients without pre-operative OAB symptoms, less post-operative OAB symptoms (P = 0.05) were reported.

CONCLUSIONS

Surgical release can be very successful in relieving obstruction due to bladder outlet obstruction (BOO) after anti-incontinence surgery. Persistent OAB symptoms and recurrent SUI are the main reasons for being dissatisfied. To lower the odds for recurrent SUI, surgical release should be performed more than 180 days after original surgery. Patients without pre-operative OAB symptoms are at higher risk of developing post-operative OAB symptoms when treatment is delayed more than 70 days.

Intralesional injection of mitomycin C at transurethral incision of bladder neck contracture may offer limited benefit: TURNS Study Group

PURPOSE

Injection of mitomycin C may increase the success of transurethral incision of the bladder neck for the treatment of bladder neck contracture. We evaluated the efficacy of mitomycin C injection across multiple institutions.

MATERIALS AND METHODS

Data on all patients who underwent transurethral incision of the bladder neck with mitomycin C from 2009 to 2014 were retrospectively reviewed from 6 centers in the TURNS. Patients with at least 3 months of cystoscopic followup were included in the analysis.

RESULTS

A total of 66 patients underwent transurethral incision of the bladder neck with mitomycin C and 55 meeting the study inclusion criteria were analyzed. Mean ± SD patient age was 64 ± 7.6 years. Dilation or prior transurethral incision of the bladder neck failed in 80% (44 of 55) of patients. Overall 58% (32 of 55) of patients achieved resolution of bladder neck contracture after 1 transurethral incision of the bladder neck with mitomycin C at a median followup of 9.2 months (IQR 11.7). There were 23 patients who had recurrence at a median of 3.7 months (IQR 4.2), 15 who underwent repeat transurethral incision of the bladder neck with mitomycin C and 9 of 15 (60%) who were free of another recurrence at a median of 8.6 months (IQR 8.8), for an overall success rate of 75% (41 of 55). Incision with electrocautery (Collins knife) was predictive of success compared with cold knife incision (63% vs 50%, p=0.03). Four patients experienced serious adverse events related to mitomycin C and 3 needed or are planning cystectomy.

CONCLUSIONS

The efficacy of intralesional injection of mitomycin C at transurethral incision of the bladder neck was lower than previously reported and was associated with a 7% rate of serious adverse events.

Pressure-flow nomogram for women with lower urinary tract symptoms

INTRODUCTION

Results of urodynamic studies performed in female patients are often difficult to interpret. The objective of the study was to develop a nomogram that would help in diagnosing functional bladder outlet obstruction (BOO) in neurologically intact women with any kind of lower urinary tract symptoms.

MATERIAL AND METHODS

From the urodynamic database adult women were chosen with maximal flow rate (Q max ) ≤ 12 ml/s in a pressure-flow study. Four criteria were used to identify a group of patients suspected of BOO: thickened bladder wall, presence of bladder diverticula, subjective improvement on α-blockers and improvement of voiding symptoms on any form of treatment. The line separating high and low pressure zones on the pressure-flow chart was established according to the position of patients who met at least one of them.

RESULTS

Sixty-seven patientswere investigated. Twenty-one women met at least one of the specified criteria. They had significantly higher voiding pressures (p det(Qmax) 35 cm H2O vs. 16.5 cm H2O; p = 0.002). A new nomogram with one separating line (p det(Qmax) = 1.5 × Q max + 10) was proposed. The difference in the distribution of women fulfilling the criteria between high pressure zone and low pressure zone was highly significant (19/35 vs. 2/32; p < 0.0001). Sensitivity, specificity, positive and negative predictive values of our nomogram in identifying patients suspected of BOO was 90.5%, 65.2%, 54.3% and 94% respectively.

CONCLUSIONS

The new nomogram can be considered a screening test which efficiently excludes obstruction among women with low Q max in a pressure-flow study.

Transient increase in circulating myeloid-derived suppressor cells after partial bladder outlet obstruction

PURPOSE

Partial bladder outlet obstruction causes a significant increase in tissue and systemic oxidative stress markers and tissue inflammatory cytokine levels. Myeloid-derived suppressor cells, IFN-γ, IL-10 and aldosterone are believed to be associated with oxidative stress and inflammation. We investigated alterations in plasma myeloid-derived suppressor cells, IFN-γ, IL-10 and aldosterone levels in partial bladder outlet obstruction and after its reversal.

MATERIALS AND METHODS

Rats with surgically induced partial bladder outlet obstruction were divided into 4 groups of 3 each, including sham treated, 4-week obstruction, and 4 and 8-week obstruction with relief. Plasma levels of circulating myeloid-derived suppressor cells, IFN-γ, IL-10 and aldosterone were assessed by flow cytometry or enzyme-linked immunosorbent assay.

RESULTS

The circulating myeloid-derived suppressor cell level was markedly increased in the obstruction group compared to the sham treated group and it returned to normal in the 4 and 8-week obstruction with relief groups. Plasma IFN-γ, IL-10 and aldosterone were similarly increased in the obstruction group and returned to normal in the 4 and 8-week obstruction with relief groups.

CONCLUSIONS

Levels of circulating myeloid-derived suppressor cells, IFN-γ, IL-10 and aldosterone were increased in rats with partial bladder outlet obstruction but returned to normal after reversal. This suggests that an increase in these parameters may be a good predictive indicator of patients at increased risk for urinary symptoms.

F2-isoprostanes as a biomarker of oxidative stress in the mouse bladder

PURPOSE

We theorized that progressive bladder dysfunction due to clinical diagnoses such as outlet obstruction occurs as a result of cyclical oxidative stress events. We hypothesized that measurement of F2-isoprostane, a marker of lipid peroxidation, could serve as a biomarker of oxidative stress in the murine bladder.

MATERIALS AND METHODS

At age 5 to 6 weeks oophorectomized female mice were subjected to 1 of 2 bladder injury models, that is partial bladder outlet obstruction or acute bladder distension. The time points studied after injury included 4, 8 and 16 weeks after obstruction, and 0 to 48 hours after acute bladder distension. In a separate group short-term repetitive acute bladder distension was performed every other day for 14 days. Bladder samples were analyzed for F2-isoprostane using gas chromatography and mass spectroscopy. Mean tissue F2-isoprostane levels were compared.

RESULTS

F2-isoprostane increased significantly after 4 weeks of partial bladder outlet obstruction from 1.46 ng/gm in controls to 2.31 ng/gm at 4 weeks (p = 0.01). Eight and 16 weeks after partial bladder outlet obstruction F2-isoprostane remained significantly elevated (2.39 and 2.48 ng/gm, respectively). Acute bladder distension resulted in a significant increase in F2-isoprostane immediately after distension compared to controls (1.6 vs 0.75 ng/gm, p = 0.04). In mice that underwent repetitive acute bladder distension F2-isoprostane did not change.

CONCLUSIONS

Measurement of tissue F2-isoprostane in the bladder reflects the progression of oxidative stress, primarily in chronic injury models such as partial bladder outlet obstruction. The usefulness of F2-isoprostane measurements in shorter term injury models requires further study.

Non-invasive urodynamics predicts outcome prior to surgery for prostatic obstruction

OBJECTIVE

To assess whether the penile cuff non-invasive urodynamic test serves as an effective diagnostic tool for predicting outcomes prior to disobstructive surgery for men presenting with voiding lower urinary tract symptoms. Patients with proven urodynamic obstruction do better after surgery. The current gold standard, invasive pressure-flow studies, imposes cost, resource demand, discomfort and inconvenience to patients.

PATIENTS AND METHODS

Patients undergoing surgery for prostatic obstruction at Palmerston North Hospital had pre-operative non-invasive urodynamics and completed an International Prostate Symptom Score (IPSS). Catheterised patients were excluded. Two months post-operatively they completed a further IPSS score. An improvement of seven or greater was defined as a clinically successful outcome. Results were compared with the outcome predicted by the nomogram supplied with the urodynamic device.

RESULTS

Data was obtained for 62 patients with mean age 70 years (range 49 to 86 years; SD 9 years). Follow-up was complete for all patients. Thirty-eight patients underwent transurethral resection and 24 holmium laser enucleation of the prostate. Mean IPSS score was 21 (range 5 to 35; SD 6) pre-operatively and 11 (range 1 to 31; SD 9) post-operatively. Thirty-five patients were predicted obstructed and 27 not obstructed. 94% of those predicted obstructed had a successful outcome (p < 0.01). 70% predicted as not obstructed did not have a successful outcome after surgery (p < 0.01).

CONCLUSION

The penile cuff test is an exciting adjunct in the decision to proceed to surgery for prostatic obstruction. Patients predicted to be obstructed have an excellent likelihood of a good surgical outcome, yet 30% of those shown not to be obstructed will still do well. Whilst numbers in our study are small, outcomes compare favourably with published results on invasive urodynamic methods.

Changes in the function and expression of T-type and N-type calcium channels in the rat bladder after bladder outlet obstruction

PURPOSE

We evaluated possible changes in the function and expression of T-type and N-type Ca(2+) channels in the bladder of rats with bladder outlet obstruction.

MATERIALS AND METHODS

Female Sprague Dawley® rats were divided into a group with bladder outlet obstruction created by partial urethral ligation and a sham operated group. Six weeks postoperatively we determined the mRNA expression of T-type and N-type Ca(2+) channels in the bladder, dorsal root ganglion and spinal cord. We also cystometrically investigated expression by intravenous administration of the T-Ca blocker RQ-00311610 or the N-type Ca(2+) channel blocker ω-conotoxin GVIA. We then performed in vitro functional studies of detrusor strips using these blockers.

RESULTS

mRNA expression of T-type Ca(2+) channels in the bladder detrusor and mucosa layers, and the spinal cord dorsal horn, and N-type Ca(2+) channels in the whole bladder and detrusor layer, and the spinal cord dorsal horn was greater in the obstructed group than the sham operated group. In obstructed rats bladder capacity and voided volume increased after RQ-00311610 administration but the number of nonvoiding contractions decreased after ω-conotoxin GVIA administration. Detrusor strips from obstructed rats showed weaker contractile responses to electrical field stimulation, particularly in regard to the purinergic component. ω-Conotoxin GVIA suppressed electrical field stimulation induced contractions only in the detrusor of obstructed rats, especially the cholinergic component.

CONCLUSIONS

Blocking T-type Ca(2+) channels increased bladder capacity while N-type Ca(2+) channel blockade inhibited nonvoiding contractions in rats with bladder outlet obstruction. Decreased bladder efferent neurotransmission occurred after bladder outlet obstruction, predominantly in its purinergic component and detrusor contractions via cholinergic neurotransmission were activated in a compensatory manner, probably via N-type Ca(2+) channel up-regulation.

Poor quality of life in patients with urethral stricture treated with intermittent self-dilation

PURPOSE

We assessed patient perceptions of regular intermittent self-dilation in men with urethral stricture.

MATERIALS AND METHODS

We constructed and distributed a visual analog questionnaire to evaluate intermittent self-dilation via catheterization by men referred for urethral stricture management at a total of 4 institutions. Items assessed included patient duration, frequency, difficulty and pain associated with intermittent self-dilation as well as interference of intermittent self-dilation with daily activity. The primary outcome was patient perceived quality of life. Multivariate analysis was performed to assess factors that affected this outcome.

RESULTS

Included in the study were 85 patients with a median age of 68 years, a median of 3.0 years on intermittent self-dilation and a median frequency of 1 dilation per day. On a 1 to 10 scale the median intermittent self-dilation difficulty was 5.0 ± 2.7, the median pain score was 3.0 ± 2.7 and median interference with daily life was 2.0 ± 1.3. Overall quality of life in patients with stricture was poor (median score 7.0 ± 2.6 with poor quality of life defined as 7 or greater). On univariate analysis younger age (p <0.01), interference (p = 0.03), pain (p <0.01) and difficulty performing intermittent self-dilation (p = 0.03) correlated with poor quality of life in a statistically significant manner. On multivariate analysis only difficulty catheterizing (p <0.01) and younger age (p = 0.05) were statistically significant predictors. Patients with stricture involving the posterior urethra had a statistically significant increase in difficulty and decrease in quality of life (each p = 0.04).

CONCLUSIONS

Most patients with urethral stricture who are on intermittent self-dilation rate difficulty and pain as moderate, and inconvenience as low but report poor quality of life.

Urodynamics and safety of the β₃-adrenoceptor agonist mirabegron in males with lower urinary tract symptoms and bladder outlet obstruction

PURPOSE

Bladder outlet obstruction often presents as storage and voiding symptoms. We investigated urodynamic parameters in men with lower urinary tract symptoms and bladder outlet obstruction treated with the β₃ agonist mirabegron, a new therapy for overactive bladder symptoms.

MATERIALS AND METHODS

A total of 200 men 45 years old or older with lower urinary tract symptoms and bladder outlet obstruction were randomized to receive once daily mirabegron 50 mg (70) or 100 mg (65), or placebo (65) for 12 weeks. The primary urodynamic parameters assessed were change from baseline to end of treatment in maximum urinary flow and detrusor pressure at maximum urinary flow (noninferiority margins -3 ml per second and 15 cm H2O, respectively). We evaluated adverse events and vital signs.

RESULTS

Treatment with mirabegron 50 and 100 mg was noninferior to placebo based on the lower and upper limits of the 95% CI, respectively, for maximum urinary flow and detrusor pressure at maximum urinary flow. The adjusted mean difference vs placebo was 0.40 (95% CI -0.63, 1.42) and 0.62 ml per second (95% CI -0.43, 1.68) for maximum urinary flow, and -5.94 (95% CI -13.98, 2.09) and -1.39 cm H2O (95% CI -9.73, 6.96), respectively, for detrusor pressure at maximum urinary flow. The incidence of adverse events was similar for mirabegron and placebo.

CONCLUSIONS

Mirabegron did not adversely affect voiding urodynamics (maximum urinary flow and detrusor pressure at maximum urinary flow) compared with placebo after 12 weeks of treatment.

Chronic cyclic bladder over distention up-regulates hypoxia dependent pathways

PURPOSE

Bladder over distention secondary to anatomical or functional obstruction can eventually lead to pathological changes, including decreased elasticity and contractile dysfunction. We hypothesized that chronic bladder distention in a murine model would activate hypoxia dependent signaling pathways despite intermittent relief of distention.

MATERIALS AND METHODS

Female C57Bl/6 mice were oophorectomized at age 5 to 6 weeks and underwent urethral catheterization and 90-minute bladder distention. Acute and chronic time points were evaluated. Bladder tissue was harvested for hematoxylin and eosin, and immunohistochemical staining with the hypoxia markers Glut-1 (EMD Millipore, Merck, Darmstadt, Germany) and Hypoxyprobe™-1. Bladder tissue was also harvested for real-time polymerase chain reaction and oxidative stress measurement. Hypoxia polymerase chain reaction arrays were done to determine changes in gene expression. Oxidative stress was measured using F2-IsoP. Functional bladder changes were evaluated using voided urine blots.

RESULTS

After acute distention and 5 consecutive distentions, bladders showed marked inflammatory changes on hematoxylin and eosin staining, and evidence of tissue hypoxia on immunohistochemistry. Quantitative real-time polymerase chain reaction revealed up-regulation of hypoxia and oxidative stress related genes, including Hif1a, Arnt2, Ctgf, Gpx1 and Hmox1. Measurements of oxidative stress with F2-IsoP did not change. Voided urine blots before and after bladder distention showed marked changes with an overactive voiding pattern.

CONCLUSIONS

Chronic bladder distention is possible in the female mouse. It generates hypoxic injury, as characterized functionally by increased voiding patterns. This bladder injury model might more closely replicate bladder dysfunction in patients with poor bladder emptying due to neurological disease, including those noncompliant with intermittent catheterization.