THE VALVE BLADDER SYNDROME: 20 YEARS LATER

Long-term bladder outcomes using a prescriber pattern scoring system for posterior urethral valves

BACKGROUND

Urinary drainage for posterior urethral valves can be achieved with valve ablation (VA) or diversion by vesicostomy (VES) or cutaneous ureterostomy (CU). The effect of these interventions on long-term bladder function remains debated, and voiding symptomatology after VES or CU reversal has been poorly characterized.

OBJECTIVE

The objective of this study was to examine the prevalence and scope of physician treatment patterns as a surrogate for retention or incontinence symptomatology among PUV patients undergoing primary VA or diversion by VES/CU and determine rates of progression to augmentation.

STUDY DESIGN

This is a single-institution retrospective cohort study. Retention Scores (R) were calculated 1 point for: retention behavior (double/timed void), alpha-blocker, intermittent catheterization, or overnight indwelling catheter. Incontinence Scores (I) were calculated 1 point for: incontinence behavior (double/timed void), oral medication, or botulinum toxin. Patients with R score above 3 or I score above 2 were deemed to have severe retention or incontinence symptomatology respectively. End stage bladder (ESB) was defined as need for bladder augmentation.

RESULTS

We identified 76 patients between 5 and 40 years old with median follow-up of 14.6 [5.0-40.4) years. There was no difference in the rates of severe retention or incontinence treatment pattern scoring between VA versus VES/CU (Figure). Rates of achieving R(1) status are similar between VA and VES/CU groups, though age of reaching R(1) was younger for those with VES/CU (4.8 years) compared to VA (6.6 years). There was no significant difference in rate of ESB by intervention category VA (9.4%) versus VES/CU (17.4%; p = 0.323).

DISCUSSION

Treatment of retention symptomatology was more common than treatment of incontinence symptomatology regardless of primary management, VA or VES/CU. This study also indicates that VES/CU patients were just as responsive as VA patients to conservative treatments (behavioral changes, pharmacotherapy) for any type of bladder symptomatology as the progression to treatment of severe symptomatology and ESB were similar between cohorts. In this cohort, bladder outcomes were not associated with type of urinary diversion (VA or VES/CU).

CONCLUSION

Long term bladder outcomes for valve patients demonstrated similar treatment patterns and progression to end-stage bladder regardless of diversion status. Patients went on to ESB approximately 4.4 years after diagnosis at similar rates between groups.

Simultaneous primary posterior urethral valves ablation and bladder neck incision may decrease kidney and bladder failure in long-term follow-up in patients with bladder neck hypertrophy and poor bladder function at presentation: report of 301 cases

OBJECTIVES

To investigate the effects of bladder neck incision (BNI) and primary valves ablation on long-term kidney and bladder function in children with posterior urethral valves (PUV) and bladder neck hypertrophy (BNH).

PATIENTS AND METHODS

From 1997 to 2016, a total of 1381 children with PUV were referred to our tertiary hospital. Of these patients, 301 PUV patients with bladder neck hypertrophy need concurrent BNI and valve ablation. All patients were followed up every 3-6 months on regular basis in first 2 post-surgical years and annually then after. The paired t-test and chi-square test were used to perform statistical analysis with p value < 0.05 defined as the level of significance.

RESULTS

Mean age at diagnosis was 7.22 ± 2.45 months (ranging from 7 days to 15 months) with a mean follow-up of 5.12 ± 2.80 years. The incidence of hydronephrosis was decreased from 266 (88.3%) at the baseline to 73 (24.3%) patients in long-term follow-up. At baseline, 188 (62.5%) patients were diagnosed with VUR, which decreased to 20 (6.6%) individuals at the end of follow-up. Bladder and renal function were improved in follow-ups following concomitant PUV ablation and BNI. No Myogenic failure was depicted in all patients with BNH. No ureteric reimplantation was needed during the two decades follow-up.

CONCLUSION

Simultaneous valve ablation with BNI may present further profits in children with PUV and BNH particularly cases of BNH with poor bladder function at the time of presentation. This method can improve the results of urodynamic and imaging studies after the surgery. We hypothesize every child with PUV presentation who has concurrent vesicoureteral reflux, CKD or persistent hydrourethronephrosis may suffer from secondary bladder neck obstruction. This secondary bladder outlet obstruction must be managed through BNI as the surgical relief.

Surrogate imaging markers of Urodynamic proven bladder dysfunction in posterior urethral valves: A comprehensive evaluation

INTRODUCTION

Although urodynamic evaluation forms the cornerstone of diagnosis and management of bladder dysfunction in posterior urethral valves (PUV), yet it could be helpful to learn if there are any non-invasive surrogate imaging markers for the same.

AIM

To study the diagnostic accuracy of various imaging surrogate markers of urodynamic proven bladder dysfunction in PUV.

METHOD

This cross-sectional study over two years included 38 children of endoscopically proven PUV. Based on bladder function on Urodynamics the patients were divided into 2 groups: Group 1: PUV with normal bladder function (n: 17, 44.7%); Group 2: PUV with impaired bladder function (n: 21, 55.3%). Voiding dysfunction, incidence of recurrent urinary tract infection (UTI), polyuria, grade of hydronephrosis, retrovesical ureteric diameter (mm) and detrusor wall thickness (DWT mm) was compared in the two groups. MCU at initial presentation and post definitive treatment was studied and a bladder hostility score (BHS) was assigned to each patient and compared in the two groups. Correlation between impaired bladder function and clinical and radiological variables was performed by using Spearman Rank correlation and data receiver operating curves (ROC) were plotted to identify the critical values predicting the probability of bladder dysfunction in PUV.

RESULTS

Mean age at evaluation was 6.1 ± 4.2 years with a mean follow-up of 5 ± 3.9 years (median: 3.5 years). Voiding dysfunction, persistent or worsening grade III and IV hydroureteronephrosis, retrovesical ureter diameter ≥13.1 mm (diagnostic accuracy: 68.4%, AUC: 0.738), DWT on full bladder ≥1.85 mm (diagnostic accuracy: 81.6%, AUC: 0.846) and pretreatment BHS ≥5.5 (diagnostic accuracy: 71.4%, AUC: 0.763) were the clinical and imaging predictors of impaired bladder function. Comparative analysis of the two groups is as shown in table.

CONCLUSION

Clinical and imaging parameters are unable to convincingly identify the type of bladder dysfunction which is often required to manage PUV patients appropriately. Increased detrusor wall thickness suggests underlying bladder dysfunction and while those with small capacity hypertonic bladders have higher mean detrusor wall thickness than those with myogenic failure, the difference was not statistically significant (p: 0.41). Attempts to predict underlying bladder dysfunction by MCU imaging may be erroneous in nearly one-third of the patients. Thus, these imaging parameters are complementary and sequential to urodynamic, which certainly continues to be the gold standard investigation to assess bladder dysfunction in PUV.

Bladder height width ratio on voiding cystourethrogram as a predictor of future valve bladder in children with posterior urethral valve

BACKGROUND/AIMS

Prompt and early treatment of valve bladder is known to improve renal outcome in patients with PUV. We hypothesized that bladder height width ratio (HWR) measurement on voiding cystourethrogram (VCUG) could predict development of valve bladder.

METHODS

All patients who underwent primary PUV ablation and evaluated later with urodynamics were included. Valve bladder was suspected when there were daytime wetting, persistent hydroureteronephrosis, and elevated detrusor pressures on urodynamics. VCUGs were analysed for HWR: maximum height/width of bladder. ROC curve analysis was performed to identify HWR that could predict development of urodynamic abnormality.

RESULTS

Between 2012 and 2017, 102 patients were studied: median age at valve ablation 25 days (3-125 days); follow-up 5 years (3-7 years). The ROC curve comparing post-ablation HWR with occurrence of valve bladder showed a cut-off of 1.45 (AUC 0.93). HWR cut-off of 1.45 had a sensitivity of 89% and specificity of 84% in predicting future valve bladder. Detrusor overactivity was noticed on urodynamics in 41/55 (74%) of those with HWR > 1.45 compared 5/47 (11%) in those with HWR < 1.45 (p = 0.001).

CONCLUSION

Bladder height width ratio on VCUG is a useful parameter to predict development of future valve bladder in children with PUV.

Can Concomitant Bladder Neck Incision and Primary Valve Ablation Reduce Early Re-admission Rate and Secondary Intervention?

Objective:

To assess the effect of bladder neck morphology and its incision (BNI) in patients with posterior urethral valve (PUV) on early reintervention rate.

Patients and methods:

Infants undergoing PUV ablation (PVA) before 24 months of age and had at least 18 months of follow-up, were categorized into three groups according to the bladder neck appearance on baseline radiological and endoscopic examination: group 1; normal bladder neck underwent PVA, group 2; high bladder neck underwent PVA plus BNI, group 3; high bladder neck underwent PVA only. Early reintervention was defined as the need for check cystoscopy because of persistent renal function deterioration, worsening hydronephrosis and/or unsatisfactory VCUG improvement during the 1st six months post primary PVA.

Results:

Between 2000 and 2017, a total of 114 patients underwent PVA and met the study criteria with a median follow-up of 58 (18-230) months. For group 1, 16 (22.9%) patients needed readmission. Check cystoscopy was free and no further intervention was performed in 5(7.5%) and re-ablation was performed in 11(15.7%) patients. For group 2, 3(14.3%) patients needed reintervention. Re-ablation and re-ablation plus BNI were performed in 1(4.8%) and 2(9.5%), respectively. For group 3, cystoscopy was free in 1(4.3%), re-ablation and re-ablation plus BNI were performed 2(8.7%) and 1(4.3%), respectively. There were no significant differences in the re-admission and re-intervention rates among the three study groups (p=0.65 and p=0.50, respectively).

Conclusion:

In morphologically high bladder neck associated PUV, concomitant BNI with PVA doesn’t reduce early re-intervention rate.

Pearls and Pitfalls in Pediatric Kidney Transplantation After 5 Decades

Worldwide, over 1,300 pediatric kidney transplantations are performed every year. Since the first transplantation in 1959, healthcare has evolved dramatically. Pre-emptive transplantations with grafts from living donors have become more common. Despite a subsequent improvement in graft survival, there are still challenges to face. This study attempts to summarize how our understanding of pediatric kidney transplantation has developed and improved since its beginnings, whilst also highlighting those areas where future research should concentrate in order to help resolve as yet unanswered questions. Existing literature was compared to our own data of 411 single-center pediatric kidney transplantations between 1968 and 2020, in order to find discrepancies and allow identification of future challenges. Important issues for future care are innovations in immunosuppressive medication, improving medication adherence, careful donor selection with regard to characteristics of both donor and recipient, improvement of surgical techniques and increased attention for lower urinary tract dysfunction and voiding behavior in all patients.

Safety and short-term efficacy of mirabegron in children with valve bladder: a pilot study

AIMS

This pilot study aims to assess the short-term efficacy and safety of mirabegron in valve bladder, an important cause of persistent hydronephrosis after successful treatment of posterior urethral valves (PUV).

METHODS

Twenty-two patients with early valve bladder (no residual PUV; persistent hydronephrosis, wetting and urodynamic evidence of detrusor overactivity) were included. Three subjective parameters: frequency, wetting episodes; patient perception of bladder condition score (PPBC) and four objective parameters: uroflow index (UI = Qave/Qmax), voided volume (VV = voided volume/ expected bladder capacity), maximum filling pressure (P det-max) and society of fetal urology (SFU) hydronephrosis grading were analysed pre- and post-3-month treatment with mirabegron (0.5-1 mg/kg/day). All patients were observed for heart rate, BP, ECG changes during therapy.

RESULTS

There was significant reduction (p = 0.001) in mean frequency (pre 15; post 10), wetting episodes (pre 5; post 2) and PPBC (pre 4; post 3). There was significant improvement (p = 0.01) in mean UI (pre 0.3; post 0.5), VV (pre 0.54; post 0.72), Pdet-max (pre 42; post 25) and hydronephrosis grade (pre 3.5; post 2.2). There were no significant side effects.

CONCLUSION

This pilot study establishes short-term efficacy and safety of mirabegron in valve bladder with overactivity. Further larger long-term studies are warranted.

Bladder function in children with posterior urethral valves: impact of antenatal versus postnatal diagnosis

Purpose:

Posterior urethral valves (PUVs) are the most common cause of congenital bladder obstruction in boys. Our aim was to assess the impact of early diagnosis and fulguration of PUVs on bladder function and compare their functional and urodynamic outcome with children who underwent delayed intervention.

Materials and Methods:

We retrospectively evaluated 153 patients who underwent primary valve ablation from two tertiary hospitals between 2001 and 2018. Patients have been divided into 2 groups, group 1 included 69 patients who were detected antenatally and underwent early fulguration of PUVs while group 2 included 84 children presented postnatally and underwent delayed valve ablation. The recorded data throughout follow-up in renal function tests, urodynamics and changes in the upper urinary tracts were evaluated and compared.

Results:

Median age at time of valve ablation was 10 days in group 1 and 7 months in group 2. The median follow-up period was 6.5 and 7 years in group 1 and 2, respectively. Chronic kidney disease (CKD) developed in 15 (22%) boys in group 1 while in group 2 it was observed in 31 (37%), p=0.04. While Q-max, mean bladder capacity and post-void residual (PVR) volumes were comparable in both groups, percent PVR was significantly higher in group 2 (3.27 vs. 1.44, p=0.002). Detrusor overactivity was slightly different in both groups (p = 0.07).

Conclusions:

Compared to delayed intervention, primary ablation of PUVs during the early neonatal life possibly provides the optimum chance to have optimum renal function without impact on bladder function.

Antenatal and postnatal management of posterior urethral valves: where do we stand?

Introduction

Posterior urethral valve (PUV) is the leading etiology of lower urinary tract obstruction (LUTO) in boys and is an important cause of end-stage renal disease (ESRD) in children. The aim of this article is to review the current status on antenatal intervention for PUV as well as postnatal medical and surgical management.

Main body

MEDLINE, EMBASE, Pubmed and Google Scholar search was conducted throughout December 2020 using the keywords: posterior urethral valves, congenital urinary obstruction, antenatal, valve bladder syndrome, medical, anticholinergics, alpha blocker, antibiotics, biofeedback, diversion, augmentation cystoplasty and renal transplantation. Only papers written in English were included. The relevant literature was summarized. Despite advances in antenatal intervention for fetal LUTO, it remains associated with considerable fetal and maternal morbidity. Patient selection criteria for antenatal intervention are greatly debated. Fetal intervention has resulted in improved perinatal survival in properly selected cases, with a questionable benefit to postnatal renal function. There is decent evidence supporting the use of anticholinergics in infants and young children following valve ablation, with less robust evidence advocating alpha blockers, overnight catheter drainage and biofeedback. The role of urinary diversion remains contentious. Optimizing bladder dynamics is crucial for successful renal transplantation outcomes.

Conclusion

While antenatal intervention has failed to improve renal function outcomes of PUV, patient-centered medical and sometimes surgical interventions can help delay the progression of chronic kidney disease. Lifelong monitoring and management of the associated bladder dysfunction is indispensable even after successful renal transplantation.

Evaluation of polyuria and polydipsia along with other established prognostic factors in posterior urethral valves for progression to kidney failure: experience from a developing country

BACKGROUND

Up to 50% of children with posterior urethral valves (PUV) progress to kidney failure. This study aimed to evaluate polyuria and polydipsia and other established variables with later development of kidney failure in children with PUV.

METHODS

Retrospective analysis of 297 children with PUV who underwent ablation of valves between January 1992 and January 2015 at our tertiary care center. Patients were divided into two groups: those who developed kidney failure (group 1) and those who did not (group 2). Specific prognostic factors for progression to kidney failure were analyzed including age at presentation < 1 year, nadir serum creatinine > 1.0 mg/dl, bilateral grade 3 or higher VUR at diagnosis, recurrent febrile UTIs, severe bladder dysfunction, polyuria, and polydipsia.

RESULTS

Thirty-eight (12.8%) patients progressed to kidney failure. Twenty-four and 64 patients were polyuric in group 1 and group 2 respectively (p < 0.001, Z-4.4666). Twenty-two and 61 patients were polydipsic in both groups respectively (p < 0.001). On univariate analysis, predicting variables were as follows: age at presentation < 1 year (p < 0.001), nadir serum creatinine > 1 mg/dl (p < 0.001), B/L high-grade VUR (p < 0.001), severe bladder dysfunction (p < 0.001), recurrent febrile UTIs (p = 0.002), polyuria (p < 0.001), and polydipsia (p < 0.001). On multivariate Cox regression analysis, severe bladder dysfunction, recurrent febrile UTIs, polyuria, and polydipsia were identified as significant prognostic factors predictive of ultimate progression to kidney failure.

CONCLUSION

Polyuria and polydipsia along with recurrent febrile UTI and bladder dysfunction are major prognostic factors affecting long-term kidney outcome in cases of PUV. Graphical abstract.

Challenges in pediatric urologic practice: a lifelong view

The role of the pediatric urologic surgeon does not end with initial reconstructive surgery. Many of the congenital anomalies encountered require multiple staged operations while others may not involve further surgery but require a life-long follow-up and often revisions. Management of most of these disorders must extend into and through adolescence before transitioning these patients to adult colleagues. The primary goal of management of all congenital uropathies is protection and/or reversal of renal insult. For posterior urethral valves, in particular, avoidance of end-stage renal failure may not be possible in severe cases due to the congenital nephropathy but usually can be prolonged. Likewise, prevention or minimization of urinary tract infections is important for overall health and eventual renal function. Attainment of urinary continence is an important goal for most with a proven positive impact on quality of life; however, measures to achieve that goal can require significant efforts for those with neuropathic bladder dysfunction, obstructive uropathies, and bladder exstrophy. A particular challenge is maximizing future self-esteem, sexual function, and reproductive potential for those with genital anomalies such as hypospadias, the bladder exstrophy epispadias complex, prune belly syndrome, and Mullerian anomalies. Few endeavors are rewarding as working with children and their families throughout childhood and adolescence to help them attain these goals, and modern advances have enhanced our ability to get them to adulthood in better physical and mental health than ever before.

International Consultation on Incontinence 2016; Executive summary: Urodynamic testing

AIMS

The International Consultation on Incontinence has published an update of the recommendations for the diagnosis and management of urine incontinence (ICI2016). This manuscript summarizes the consultations committee-recommendations with regard to urodynamic assessment.

METHODS

Expert consensus on the basis of structured evidence assessment has been the basis of the consultations publication and has been summarized by the committee for this manuscript.

RESULTS

Patients that are not satisfied with their initial management on the basis of their reported signs and symptoms of urinary incontinence, as well as all patients with neurological abnormalities that are potentially relevant for the function of the lower urinary tract, may very likely profit from objective diagnosis and staging and grading of their dysfunction, with urodynamic testing, regardless their age, vulnerability and/or comorbidities. The principles and technical innovations as well as the principal recommendations for the utilization of (invasive) urodynamic assessment for women, men, children, and vulnerable elderly, with or without neurogenic lower urinary tract dysfunction with urinary incontinence are provided in this abbreviated ICI recommendations-document.

CONCLUSIONS

The ICI2016 committee on urodynamics presents an executive summary of the most important reasons and recommendations for the use of urodynamic investigations for patients with urinary incontinence.

Current strategies to predict and manage sequelae of posterior urethral valves in children

Posterior urethral valves (PUV) constitute a significant urological cause of chronic kidney disease (CKD) in children. The condition is characterised by the unique pathophysiology of the evolution of bladder dysfunction after relief of obstruction, which contributes to CKD. Improvements in prenatal diagnosis followed by selective foetal intervention have not yet produced improvement in long-term renal outcomes, although better patient selection may alter this in the future. Proactive management with surveillance, pharmacotherapy, timed voiding, double voiding, and/or assisted bladder-emptying, is being increasingly offered to those with severe bladder dysfunction and has the potential of reducing the burden of renal disease. Clinicians are currently able to counsel regarding the prognosis using serum creatinine and other emerging markers. However, much of this work remains to be validated. Satisfactory graft survival rates are now reported with aggressive management of bladder dysfunction in children who are candidates for renal transplantation. Knowledge gaps exist in identifying early markers of renal injury, risk stratification, and in understanding patient and carer perspectives in PUV.

Bladder contractility index in posterior urethral valve: A new marker for early prediction of progression to renal failure

INTRODUCTION

Posterior urethral valve (PUV) is the most common cause of pediatric end stage renal disease (ESRD), imposing a major health burden on medical community caregivers and adversely affecting the quality of life of patients. Chronic kidney disease (CKD) stage III or estimated GFR of <60 mL/min/1.73 m² is known to be associated with more adverse renal, cardiovascular, and clinical outcomes. Thus, it is desirable to identify factors predicting the rapid and early progression of disease. In the present study, baseline characteristics and urodynamic study (UDS) parameters of boys with PUV are correlated with CKD progression to IIIB or more.

AIMS AND OBJECTIVES

To study the correlation of bladder contractility index (BCI) with development of CKD stage IIIB (eGFR of <45 mL/min/1.73 m²) or more in boys with PUV.

METHODOLOGY

Baseline characteristics and demographical variables of 270 boys with PUV who underwent valve fulguration at the hospital between 2000 and 2010 were recorded and certain UDS parameters in follow-up were noted such as bladder contractility index (BCI = PdetQmax + 5 Qmax), end filling pressure (EFP), compliance (ΔC), bladder outlet obstruction index (BOOI = Pdet Qmax - 2 Qmax), and bladder volume efficiency (BVE = Voided volume/total capacity). Fate of patients in follow-up was checked in December 2015.

RESULTS

Mean follow-up period was 8.5 years (range 5-15) and median age of patients at the time of evaluation was 5.8 years. At the end of the study, 21.8% (59/270) of patients had progressed to CKD stage IIIB or more (primary end point). Cox regression analysis was applied to risk factors predicting development of CKD stage IIIB. In the multivariate model, bladder contractility index (BCI) (HR 0.8; p = 0.004), end filling pressure (EFP) (HR 2.1; p = 0.010), and compliance (ΔC) (p = 0.020) were significantly associated with the event (i.e. an eGFR of <45 mL/min/1.73 m²), whereas BOOI (p = 0.053) and bladder BVE (p = 0.267) were not. ROC cut-off level for BCI predicting the primary end point was 75 (AUC ± SE, 0.73 ± 0.03, sensitivity of 78.2%, and specificity of 62.5%).

CONCLUSION

In a well performed UDS, BCI may be a useful tool for early detection of boys with PUV who are likely to progress to CKD stage IIIB or more.

Prediction of need for intervention in posterior urethral valves: Use of urine osmolality

AIM

Renal tubular dysfunction (RTD) causing obligate production of hypoosmolar urine in boys with posterior urethral valves (PUVs) has been described. It is not known how clinically significant this is. We hypothesize that a feedback loop is present in many PUV boys who suffer deterioration of their lower urinary tract (LUT). RTD results in hypoosmolar urine, obligate polyuria, and bladder stretch-injury. The increasing back-pressure worsens RTD, thus exacerbating the injury. Coexisting renal dysplasia and acquired renal scarring exacerbate this. We compared the concentrating ability (random clinic urine osmolality) of PUV boys who had no LUT deterioration to those who required intervention, examining the confounding effect of renal impairment with a subgroup analysis comparing those with plasma creatinine ≤80μmol/l.

METHODS

A retrospective review of our PUV database was performed. Age, intervention, and highest recorded random clinic urine osmolality (>1year) with concurrent plasma creatinine were recorded (normal urine osmolality 500-850 mOsm/kg). Data are given as median values, analyzed by Mann-Whitney u-test, with P<0.05 deemed significant.

MAIN RESULTS

Urine osmolality was available in 77 boys with PUV out of 125 in our series. Of these, 34 required subsequent intervention (e.g., Mitrofanoff procedure, bladder augmentation). Age at testing trended towards being higher in the intervention group [7.9 (4.3-10.9) years vs. nonintervention 6.3 (4-8.4); P=0.06]. Urine osmolality was significantly reduced in the intervention group [411(293-547) vs. 631 (441-805) mOsm/kg; P<0.001]. Subgroup analysis comparing only those with creatinine ≤80μmol/l was respectively 451 (322-567) mOsm/kg (n=22) vs. 645 (469-810) mOsm/kg (n=40), P<0.01.

CONCLUSION

This study confirms that hypoosmolar urine is highly associated with progression of LUT dysfunction, requiring intervention. Even boys with normal creatinine values have a greater risk of LUT deterioration if they have a RTD and produce hypoosmolar urine.

LEVEL OF EVIDENCE

IV (retrospective service development project).

Preventative effects of a HIF inhibitor, 17-DMAG, on partial bladder outlet obstruction-induced bladder dysfunction

Posterior urethral valves are the most common cause of partial bladder outlet obstruction (PBOO) in the pediatric population. Pathological changes in the bladder developed during PBOO are responsible for long-lasting voiding dysfunction in this population despite early surgical interventions. Increasing evidence showed PBOO induces an upregulation of hypoxia-inducible factors (HIFs) and their transcriptional target genes, and they play a role in pathophysiological changes in the obstructed bladders. We hypothesized that blocking HIF pathways can prevent PBOO-induced bladder dysfunction. PBOO was surgically created by ligation of the bladder neck in male C57BL/6J mice for 2 wk. PBOO mice received intraperitoneal injection of either saline or 17-DMAG (alvespimycin, 3 mg/kg) every 48 h starting from day 1 postsurgery. Sham-operated animals received injection of saline on the same schedule as PBOO mice and served as controls. The bladders were harvested after 2 wk, and basal activity and evoked contractility of the detrusor smooth muscle (DSM) were evaluated in vitro. Bladder function was assessed in vivo by void spot assay and cystometry in conscious, unrestrained mice. Results indicated the 17-DMAG treatment preserved DSM contractility and partially prevented the development of detrusor over activity in obstructed bladders. In addition, PBOO caused a significant increase in the frequency of micturition, which was significantly reduced by 17-DMAG treatment. The 17-DMAG treatment improved urodynamic parameters, including increases in the bladder pressure at micturition and nonvoid contractions observed in PBOO mice. These results demonstrate that treatment with 17-DMAG, a HIF inhibitor, significantly alleviated PBOO-induced bladder pathology in vivo.

Cystometrogram appearance in PUV is reliably quantified by the shape,wall, reflux and diverticuli (SWRD) score, and presages the need for intervention

OBJECTIVE

Radiological bladder abnormalities in boys with posterior urethral valves (PUV) are well recognised; however, the assessment is subjective. The shape, wall, reflux and diverticuli (SWRD) score objectively assesses shape, wall, reflux and diverticuli in a simple way. This study was undertaken to demonstrate that the SWRD score is reliable, reproducible and correlates with bladder outcome and videourodynamic (VUD) assessment in boys with PUV.

MATERIALS AND METHODS

Three blinded assessors determined the SWRD scores of PUV bladders from cystometrograms taken during VUD from September 2012 to October 2013. The scores were correlated with clinical outcome and VUD pressure measurements. Data were given as median (interquartile range), non-parametric tests used as appropriate (Mann-Whitney U test, or Kruskall-Wallis) and P < 0.05 was taken as significant.

RESULTS

A total of 55 boys with PUV underwent VUD assessment, for which 52 cystometrograms were available. The SWRD score for non-operative management was 1.0 (0.1-1.9) vs 2.0 (1.0-3.3) for operative intervention, P = 0.018 (Summary Figure). The SWRD score for compliant bladders was 1.1 (0.6-2.0) vs hypercompliant 1.7 (0.5-2.8) vs non-compliant 3.3 (2.8-5.0), Kruskall-Wallis P = 0.011. The hostile detrusor overactivity (DO) bladders (Pdet >40 cmH₂O) had a SWRD score of 2.0 (1.3-3.7) vs 1.0 (0.5-2.5) for low-pressure DO bladders, P < 0.05.

DISCUSSION

In this series of patients, increasingly distorted bladder shape was seen to be associated with poor bladder dynamics on VUD. Patients with poorly compliant bladders had a significantly higher SWRD score than normal or megacystis patients. Severe DO was also significantly associated with a high SWRD score. Therefore, the radiological appearance of a hostile bladder represented a marker for high intravesical pressure. VUR and bladder diverticuli may lead to spurious pressure measurements during VUD; however, the SWRD score provided an independent mechanism with which to objectively assess these patients, even in the presence of gross VUR.

CONCLUSIONS

The SWRD score is a simple and objective scoring system for the radiological abnormalities of PUV bladders. It correlates with clinical outcome and VUD assessment of compliance and DO, but is independent of pressure measurements and so not confounded by VUR acting as a 'pop-off' mechanism.

Effect of Botox injection at the bladder neck in boys with bladder dysfunction after valve ablation

OBJECTIVE

After posterior urethral valve ablation, some boys are still have a hostile bladder. We conducted a prospective randomized study to determine if Botox injection at the bladder neck will help improve vesical dysfunction in this subgroup of boys or not.

PATIENTS AND METHODS

Twenty boys with history of posterior urethral valve ablation and severe bladder dysfunction with a mean age of 16 months were studied. Cases were further randomized into two groups. Group I (study group) had endoscopic injection of a single dose of 100 IU of Botox into the hypertrophied bladder neck at 3, 6, and 9 o'clock. Group II (control group) patients with the same parameters had urethroscopy to exclude residual valves. Both groups had the standard conservative treatment. Cases were followed after 6 months of initiating the management protocol. This includes laboratory studies (urine culture and sensitivity, blood urea nitrogen, serum creatinine), ultrasound of the urinary tract. Voiding cysto-urethrogram and urodynamic study (pressure flow study).

RESULTS

There was no statistical difference in both groups regarding rate of urinary tract infection, improvement of hydronephrosis, resolution of vesico-ureteral reflux, creatinine level at the start or at the end of the study. Urodynamic parameters revealed an increase in cystometric capacity in both groups at the end of the study but without statistical difference. The mean voiding pressure reduced significantly in both groups but without statistical difference.

CONCLUSIONS

Temporarily abolishing the effect of bladder neck by Botox injection does not seem to improve the outcome of those boys who had a severe voiding dysfunction after valve ablation.

Posterior urethral valve: delayed presentation in adolescence

Posterior urethral valves (PUV) are now commonly suspected on antenatal ultrasound, but can present with a broad spectrum of severity postnatally. Rarely, the diagnosis is missed until adolescence or adulthood when the patient usually presents with lower urinary tract symptoms. We describe an even rarer case of PUV in a late adolescent who first presented with preserved renal function and urinary incontinence. We review the literature on presentation, natural history and outcomes of both early and late presenting PUV cases.

Posterior urethral valves and adult sexual function

OBJECTIVES

To evaluate sexual function and fertility in adult patients treated for posterior urethral valves (PUV) in childhood and to compare these patients with the normal population. To examine if patient characteristics such as chronic renal failure (CRF), history of cryptorchidism and bladder neck incision in childhood have an impact on sexual function.

PATIENTS AND METHODS

Information on sexual function was assessed using questions from the International Index of Erectile Function (IIEF). In addition, the patients were asked if they had had children or been treated for CRF. Out of 108 adult patients with PUV, 67 (62%) returned the questionnaires. Sexual function in these patients was compared with 201 controls and paternity rates were compared with a national database.

RESULTS

The mean (sd) age of the patients and controls was 38 (9) and 38 (7) years, respectively. Six percent of the patients and 9% of the controls reported problems in achieving erection during sexual stimulation and 9% of the patients and 10% of the controls reported problems with the hardness of erection (P = nonsignificant). Ejaculation was absent in 1/61 sexually active patients (2%). The only significant risk factor in patients for erectile dysfunction (ED) was increasing age. Thirty-three (49%) of all 67 patients and four (57%) of the seven patients with kidney transplantation had had children. The paternity rates were similar to those in corresponding age groups of the general Finnish population. Eight patients (12%) had attempted to have children without success.

CONCLUSIONS

Men treated for PUV have a similar prevalence of ED and similar paternity rates to men without PUV. Erectile function and paternity rates can be satisfactory in spite of CRF.

Age-related changes in expression in renal AQPs in response to congenital, partial, unilateral ureteral obstruction in rats

Previously we demonstrated that neonatally induced partial unilateral ureteral obstruction (PUUO) in rats is associated with changes in the abundance of renal acid-base transporters that were paralleled by reduction in renal functions dependent on the severity and duration of obstruction. The aim of the present study was to identify whether changes in renal aquaporin abundance are age-dependent. Semiquantitative immunoblotting and immunohistochemistry were used to examine the changes in abundance of AQP1, AQP2, p-S256AQP2 (AQP2 phosphorylated at consensus site Ser(256)) and AQP3 in the kidneys of rats with neonatally induced PUUO within the first 48 h of life, and then monitored for 7 or 14 weeks. Protein abundance of AQP2 and AQP3 increased in both obstructed and non-obstructed kidneys 7 weeks after induction of neonatal PUUO (PUUO-7W). In contrast, AQP1 and AQP2 protein abundance in the obstructed kidney were reduced after 14 weeks of PUUO (PUUO-14W). Importantly, pS256-AQP2 protein abundance was reduced in obstructed kidneys of both PUUO-7W and PUUO-14W. Immunohistochemistry confirmed the persistent pS256-AQP2 downregulation in both PUUO-7W and PUUO-14W rats. The study shows that the protein abundance of AQP1, AQP2, and AQP3 in the obstructed kidney is increased in PUUO-7W, which may be a compensatory phenomenon and reduced in PUUO-14W rats suggesting a time-/age-dependent dysregulation in response to PUUO. pS256-AQP2 protein abundance is reduced consistent with obstruction-induced direct effects in the apical part of the collecting duct principal cells in response to PUUO.

Urodynamic testing in children: indications, technique, interpretation and significance

PURPOSE

Urodynamic studies in children have been performed with increasing frequency as the techniques, reproducibility and reliability of the testing have been refined in the last quarter century. Children of all ages and with a variety of comorbidities are now often referred for urodynamic testing to evaluate and understand the causes of incontinence and/or persistence of lower urinary tract symptoms, as well as to appropriately define and evaluate treatment regimens.

MATERIALS AND METHODS

We performed a MEDLINE® search for relevant articles on urinary tract dysfunction, neurogenic bladder and urodynamic studies in the pediatric population. We also included 3 major textbooks that addressed the subject matter.

RESULTS

We review the current indications for urodynamic studies in children with nonneurogenic and neurogenic bladder dysfunction. We summarize the components and techniques of the current practice of urodynamic studies in the pediatric population, and explain how to identify abnormal results.

CONCLUSIONS

The use of urodynamic studies in pediatrics has become almost mandatory for the effective management of severe or therapy resistant urinary tract abnormalities. This review may be used as a guideline for the appropriate application of urodynamics in this patient population.

Lower urinary tract symptoms in adults treated for posterior urethral valves in childhood: matched cohort study

PURPOSE

We compared the prevalence and bother of lower urinary tract symptoms in adults treated for posterior urethral valves in childhood and population based controls.

MATERIALS AND METHODS

Questionnaires were mailed to patients 18 years and older treated at our institution for posterior urethral valves. Of the 124 patients 68 (64.2%) participated, 18 were unavailable and 38 did not participate. Age and sex matched controls were randomly identified from a population based study (response proportion 62.4%). Danish Prostatic Symptom Score was used to assess occurrence (never/rarely/often/always) and bother (none/small/moderate/major) of 12 different lower urinary tract symptoms. Chi-square test was used for the analyses stratified by patient/control status, with the 4-point ordinal scale as the outcome.

RESULTS

Median age of 68 patients with posterior urethral valves and 272 controls (ratio 1:4) was 38.5 years (range 18 to 57). Overall, at least 1 moderate or severe lower urinary tract symptom was reported by 32.4% of patients with posterior urethral valves and 15.8% of controls (p=0.002). Mild hesitancy, weak stream, incomplete emptying and straining were reported twice as often by patients with posterior urethral valves as by controls (p<0.05). Prevalence of any urgency incontinence (14.7% vs 4.8%, p=0.014) and any stress incontinence (11.8% vs 3.0%, p=0.005) was increased at least 3-fold in patients with posterior urethral valves compared to controls. Furthermore, prevalence of bother from several lower urinary tract symptoms was increased approximately 2-fold in patients with posterior urethral valves compared to controls (p<0.05). However, most patients and controls reported no or small bother.

CONCLUSIONS

In adulthood the occurrence and bother of most lower urinary tract symptoms are increased approximately 2-fold in patients with posterior urethral valves compared to the general population. However, in this cohort of young and middle-aged men most symptoms are mild.

Can a pressure-limited vesico-amniotic shunt tube preserve normal bladder function?

INTRODUCTION

We have previously shown that a vesico-amniotic shunt (V-A shunt) produces fibrotic bladders with poor compliance in normal fetal lambs. We hypothesized that using a ventriculo-peritoneal shunt (V-P shunt) as a V-A shunt in normal bladders may preserve the filling/emptying cycle and normal bladder development.

MATERIALS AND METHODS

The V-A shunting in normal fetal lambs was performed at 74 days of gestation using a V-P shunt (group A) and a free-draining shunt tube (group B). Sham-operated lambs were used as controls (group C). They were all delivered at term (145 days), and the pressure-volume curve, bladder volume, and histologic features of the bladder wall were compared.

RESULT

The mean bladder volume in group B (n = 5), 5 +/- 2.4 mL, was significantly smaller (P < .01) than that in group A (n = 6), 53 +/- 14 mL, and group C (n = 10), 57.3 +/- 12 mL. The bladder wall thickness in group A was 338 + 94.2 microm; group B, 741 +/- 128 microm; and group C, 374 +/- 120 microm. Group B bladders had very poor compliance with thick bladder wall (P < .01). Histologically, group B bladders showed prominent submucosal fibrotic change, but group A bladders were similar to controls.

CONCLUSION

This study shows that a pressure-limited shunt tube for V-A shunting preserves the normal fetal bladder development.

Augmentation ureterocystoplasty in boys with valve bladder syndrome

OBJECTIVE

Children with valve bladder syndrome represent the worst end of the posterior urethral valve spectrum. When conservative measures fail to control recurrent infections, prevent deterioration of the upper tract (in the form of increasing hydronephrosis and or worsening of kidney function) and improve incontinence, augmentation cystoplasty is considered. In most of these boys, renal insufficiency precludes the use of intestine for augmenting the bladder. Our aim was to evaluate the efficacy and safety of ureterocystoplasty in managing children with valve bladder syndrome.

PATIENTS AND METHODS

Eight boys (mean age 5 years) with valve bladder syndrome were included in this study. All boys had successful valve ablation at the time of presentation. When conservative treatment failed, ureterocystoplasty was scheduled. The entire ureter was folded and used in four boys after nephrectomy for a non-functioning kidney. The lower dilated ureter was used to augment the bladder, and transureteroureterostomy in two and re-implantation of the remaining ureter in two were performed. Radiological and urodynamic investigation was performed preoperatively and postoperatively at 3, 6 and 12 months. Improvement of hydroureteronephrosis was judged by ultrasound.

RESULTS

Bladder capacity (as measured during cystometry at 30 cmH(2)O) and compliance were significantly improved in all children following the procedure (P<0.001), and reached or exceeded the normal calculated capacity for age-matched boys. Hydroureteronephrosis improved in six boys (75%). The procedure avoids almost all the complications of enterocystoplasty. Clean intermittent self-catheterization was performed in all cases routinely after surgery, weaning off as judged by the voiding pattern of the child.

CONCLUSION

Ureterocystoplasty is an ideal option for augmenting the hypocompliant bladder in boys with valve bladder syndrome. The entire ureter or the dilated lower part can be used. This is a solution for boys with impaired renal function when enterocystoplasty cannot be performed.

The Effects of Bladder Neck Incision on Urodynamic Abnormalities of Children With Posterior Urethral Valves

PURPOSE

We evaluated the effects of simultaneous bladder neck incision and valve ablation on urodynamic abnormalities in patients with posterior urethral valves.

MATERIALS AND METHODS

A total of 46 patients with posterior urethral valves entered our prospective study between 1998 and 2003. Group 1 consisted of 22 patients who underwent simultaneous valve ablation and bladder neck incision at the 6 o'clock position. Group 2 consisted of 24 age matched patients with comparable prognostic factors who underwent simple valve ablation. Trends in renal function tests, urodynamics and changes in the upper urinary tracts were evaluated throughout followup.

RESULTS

Mean patient age at presentation was 1.6 years in group 1 and 1.8 years in group 2. Preoperatively, all patients in both groups had hypercontractile bladders and comparable high maximum voiding detrusor pressures. At the end of followup (mean 4.5 years) no patient in group 1 had bladder hypercontractility or detrusor overactivity, and the mean maximum voiding detrusor pressure was 53 +/- 15 cm H(2)O. In comparison, 9 patients in group 2 had bladder hypercontractility, 6 had detrusor overactivity and the mean maximum voiding detrusor pressure was 87 +/- 45 cm H(2)O (p <0.01). Myogenic bladder failure developed in 5 patients in group 2. The number of patients requiring anticholinergic medication and the duration of treatment were also significantly higher in group 2 compared to group 1.

CONCLUSIONS

Valve ablation with bladder neck incision may result in better bladder urodynamic function in comparison to simple valve ablation. However, long-term studies with followup through puberty are required to evaluate the final effects on renal function.

Changing concepts of bladder regeneration

During the last decade, there has been a dramatic increase in studies aimed at regeneration of the urinary bladder. Many studies employed animal-derived or synthetic materials as grafts for experimental bladder augmentation models, with or without additional measures to promote regeneration, such as autologous cell transplantation or growth factor loading. However, in spite of encouraging results in several reports, few methodologies have shown proven definitive clinical utility. One major problem in these studies is the lack of a clear distinction between native and regenerated bladder in total bladder function after augmentation. Another crucial problem is the absorption and shrinkage of larger grafts, which may result from insufficient vascular supply and smooth muscle regeneration. In contrast, researchers have recently attempted to establish alternative regenerative strategies for treating bladder diseases, and have employed far more diverse approaches according to the various pathological conditions to be treated. For total replacement of the bladder after cystectomy for invasive bladder cancer, urothelium-covered neobladder with non-urinary tract backbone remains a viable choice. In addition, functional bladder diseases such as urinary incontinence, weak detrusor, or non-compliant fibrotic bladder have also been major targets for many leading research groups in this field. These conditions are studied much more from different therapeutic standpoints, aiming at the prevention or reversal of pathological conditions in muscle remodeling or neural control. Such altered research direction would inevitably lead to less surgically based basic biological research, and also would include a far wider spectrum of adult and pediatric bladder diseases, from overactive bladder to dysfunctional voiding.

Does bladder augmentation stabilize serum creatinine in urethral valve disease? A series of 19 cases

OBJECTIVE

This study evaluates the results of bladder augmentation (BA) in 19 boys with posterior urethral valves, especially as regards its efficacy in stabilizing serum creatinine.

PATIENTS AND METHODS

In the period 1995-2005, 188 patients with urethral valves were surgically managed. Nineteen of these had undergone BA as a part of their surgical management after initial endoscopic valve ablation in 15 and diversion in four boys. The mean serum creatinine at the time of BA was 2.11 mg/dl.

RESULTS

BA stabilized the serum creatinine in 14 but failed to do so in five boys. A serum creatinine level of more than 2mg/dl at the time of BA was associated with a significantly worse rate of success. BA as part of an undiversion procedure in three boys was unsuccessful.

CONCLUSION

In an economic milieu where renal transplantation is not available for the majority of deserving children, careful selection is required before BA is considered as a surgical solution for the valve bladder. BA, when otherwise indicated, has been beneficial in children with pre-augmentation creatinine up to 2 mg/dl.

Urodynamic investigation of valve bladder syndrome in children

OBJECTIVE

To investigate urodynamic manifestations and their relationship with the postoperative experience of children with valve bladder syndrome (VBS).

METHODS

Included were 16 children (mean age 3.2+/-1.8 years) with VBS, who were divided into two groups. The urodynamic study was performed less than 1 year in group 1 (seven boys, aged 1-1.9 years) and more than 1 year in group 2 (nine boys, aged 2.9-6.5 years) after urethral valve fulguration; at the time of operation patients were less than 2 years old. Standards of the International Children's Continence Society were respected, and results were compared between the two groups.

RESULTS

Compared to group 1, group 2 showed a significant decrease in maximum detrusor voiding pressure (Pdet.void.max) and bladder compliance (BC), and an increase in post-voiding residual (PVR) and maximum bladder capacity (MBC) (p<0.05), but the difference in detrusor instability was not significant (p>0.05), Pdet.void.max and PVR were 56.2+/-14.1 cmH(2)O and 96.6+/-52.4 ml, respectively, in group 2, and there were more intermittent detrusor contractions during voiding in this group.

CONCLUSION

Patients with VBS frequently present with multiple bladder dysfunctions that can be diagnosed accurately using urodynamics. Even after urethral valve fulguration Pdet.void.max and BC were inclined to decrease, while PVR and MBC increased with the growth of the children.

Experimental short-term fetal bladder outflow obstruction: I. Morphology and cell biology associated with urinary flow impairment

PURPOSE

In fetal sheep, combined urethral and urachal obstruction initiated at 75 days' gestation and maintained for 30 days led to dysmorphic bladders, similar to those found in humans with prune belly syndrome, and uniformly disrupted kidney development. We aimed to create a less severe model of fetal bladder outlet obstruction, more closely resembling infants with posterior urethral valves, and additionally to further our understanding on the role of the urachus. We hypothesized that milder morphological renal tract changes would occur after shorter term experimental obstruction.

MATERIALS AND METHODS

Male fetal lambs were assigned to urachal and urethral ligation, urachal ligation only or sham operations. Analyses were performed after 9 days.

RESULTS

Concurrent urachal and urethral obstruction resulted in increased bladder weight, and protein and DNA content. Detrusor smooth muscle was well maintained, as assessed by light and electron microscopy, although urothelia showed basal apoptosis. Bladder obstruction led to hydronephrosis but failed to produce significant perturbations in urine osmolality. The nephrogenic cortex was either well preserved or was replaced by glomerular cysts; the latter group tended to have heavier bladders. Urachal obstruction alone produced similar changes suggesting that the male sheep fetal urethra is a high-resistance conduit in mid-gestation.

CONCLUSIONS

Concurrent urachal and urethral obstruction, or urachal obstruction alone, initiated in mid-gestation and maintained for 9 days leads to bladder overgrowth but preserved renal tubular function. In future, it will be interesting to determine whether bladder decompression around this stage leads to reversal of bladder overgrowth and/or ameliorates severe renal tract damage described after longer term fetal bladder outflow obstruction.

The Impact of Late Presentation of Posterior Urethral Valves on Bladder and Renal Function

PURPOSE

We retrospectively reviewed the records of patients with late presentation of PUVs, and compared bladder and renal function to that in patients with an early diagnosis of PUVs.

MATERIALS AND METHODS

We retrospectively reviewed the charts of 36 males (mean age at diagnosis 8.8 years, range 5 to 14) with late presentation of PUVs who were treated at our institution between 1986 and 2004. Of these patients 20 had undergone urodynamic evaluation during followup (mean age 10.65 years, range 5 to 23). We chose as controls 19 age matched children with PUVs who were diagnosed and treated before age 5 years and underwent urodynamic evaluation during followup (mean age at urodynamic evaluation 8.52 years, range 6 to 15). Urodynamic parameters were compared between the 2 patient groups. Renal function in the late presenting cases was also compared to controls.

RESULTS

The most common symptoms at presentation were diurnal enuresis (17 patients, 47.2%) poor stream (7, 19.4%) and urinary retention (5, 13.9%). Overall, urodynamic bladder abnormalities were detected in 17 of 20 patients (85%), detrusor overactivity in 3 (15%), significant post-void residual in 9 (45%) and bladder capacity greater than expected for age in 9 (45%). No significant difference in bladder capacity, compliance or post-void residual was demonstrated between the late presenting and control groups. Only detrusor overactivity was significantly lower in the late presenting group (p = 0.013). After a mean followup of 67.03 months age specific creatinine levels were increased in 13 of 27 patients (48.1%), including 7 (25.9%) with ESRD. Renal function was significantly impaired in the late presenting group compared to controls (48.1% vs 13.7%, p = 0.001).

CONCLUSIONS

We found a significantly lower rate of detrusor overactivity (15%) in patients with late presenting PUVs. Comparison of urodynamic parameters between the early and late presenting groups did not reveal any significant difference. This similar pattern of bladder dysfunction, independent of age at relief of obstruction, may indicate a common pathophysiological etiology for bladder dysfunction in all patients with PUVs. Also, renal function was significantly impaired in the late presenting group in this series.

Renal transplantation in children with posterior urethral valves

The objective of this study was to analyze whether renal transplantation (RT) in children with posterior urethral valves (PUV) constitutes a special group with respect to groups with different etiologies of end-stage renal disease (ESRD). Between 1979 and 2004, 22 RT were performed in 19 children with PUV. The median age at RT was 10 years (range: 1.3-17). Immunosuppression was provided by triple therapy and polyclonal/monoclonal antibodies. This group was compared with the two control groups: (1) glomerulopathy (n=62) and (2) pyelonephritis/dysplasia (n=42) without lower urinary tract disease, transplanted in the same period. Ten graft losses occurred in 22 transplants: thrombosis (2), acute rejection (3), chronic graft nephropathy (2), and death of patients (3) with a functioning graft in the 1st postoperative month. We did not find significant differences versus the control group in renal function or probability of graft or patient survival at 1, 5, and 10 years. We observed a greater risk of urological complication in patients with PUV. RT with PUV constitutes a special group due to the compulsory young age and the need for careful and complex medicosurgical management; nevertheless, the results achieved were similar to those obtained in our general RT population.

First report of overactive detrusor in association with hypospadias detected by urodynamic screening

AIMS

The purpose of this study was to determine urodynamic features in hypospadic patients.

METHODS

Thirty-seven patients with hypospadias (distal: 31, proximal: 6) underwent preoperative urodynamic study according to International Continence Society (ICS) recommendations. Statistical analysis were done for comparison between urethral obstruction and non-obstruction in patients with detrusor overactivity (DO) plus the relationship of DO with localization of hipospadias.

RESULTS

Nearly 45.9% of the patients showed overactive detrusor. Urethral obstruction was found in 60.8% of the patients. The rate of DO was higher in proximal hipospadias, and urethral obstruction than distal type, and non-obstructed patients (P > 0.005). The means overall cystometric capacity, maximum voiding detrusor pressure and maximal urinary flow measured were 132.6 +/- 111.14 ml (range 21-610), 72 +/- 53 cmH2O (range 12-181), and 7.9 +/- 7.1 ml/sec (range 2-30 ml/sec), respectively.

CONCLUSIONS

To the best of our knowledge, this is the first study ever to show that overactive detrusor is an accompanying entity in the hypospadic patients.

Initial and long-term management of posterior urethral valves

Posterior urethral valves are the most common cause of congenital obstructive uropathy, resulting in renal failure in childhood. Nowadays, in most cases, diagnosis is suggested by antenatal ultrasound. However, antenatal intervention has not resulted in a significantly improved outcome. Endoscopic valve ablation is the initial treatment in most of these neonates, but others procedures, like vesicostomy or ureterostomy, can also be justified in some particular cases in order to improve renal function prognosis. Different factors like bladder dysfunction, VUR, polyuria and proteinuria, can be responsible for the slow and progressive deterioration in renal function that some of these patients show over the years. By treating them all, we may prevent or delay the onset of end stage renal disease.

Pediatric renal transplantation and the dysfunctional bladder

We retrospectively reviewed our long-term experience with pediatric renal transplantation into a dysfunctional lower urinary tract to evaluate graft survival, function, and special urological complications. Between 1967 and March 2000, a total of 349 renal transplantations were performed in children younger than 18 years. Malformations of the lower urinary tract were the reasons for end-stage renal failure in 66 children (18.6%). The cause of urinary tract disorders included: meningomyelocele connected with neuropathic bladder (n = 4 transplantations); prune belly syndrome (n = 5 transplantations); VATER association (n = 2 transplantations); posterior urethral valves (n = 27 transplantations); and vesico-uretero-renal reflux (n = 28 transplantations). The majority of the patients underwent surgical interventions to preserve renal function or to prepare renal transplantation. The 1- and 5-year graft survival rate was evaluated with special reference to the underlying disease. The 1-year graft survival rate in all children with lower urinary tract malformations was 83.3%, compared with 88% for all children. In those children with vesico-ureteral reflux, it was 92.8% and in the children with Vater association and prune belly syndrome, it was 85.7%. One graft was lost in the children who had neurogenic bladder, so the 1-year graft survival rate was 75%. The worst 1-year graft survival rate was obtained for boys who had posterior urethral valves (1-year graft survival rate: 74%; 5-year graft survival rate: 62.9%). Concerning the 5-year graft survival rate, it was 70% for all children with malformations of the urinary tract. The best rate was obtained for children with reflux in the native kidneys (78.5%), followed by those with VATER association and prune belly syndrome. As an additional child with neurogenic bladder lost his graft, the 5-year graft survival rate was 50%. Pediatric renal transplantation into a dysfunctional bladder can be connected with high urological complication rates which may contribute to worse graft survival. The 1- and 5-year graft survival rate in children with malformations of the lower urinary tract is worse than in children without bladder dysfunction. We regarded a striking difference between graft survival and the urological disorders which led to renal insufficiency. We obtained the worst graft survival rates in children with posterior urethral valves which are usually connected with bladder emptying problems and dysfunctional voiding. Potential pediatric transplant recipients must be classified according to pathophysiological as well as anatomical abnormalities of the urinary tract and all urological problems have to be solved prior to transplantation. At our center, living donors are favored to plan transplantation of these children properly.

Early release of neonatal ureteral obstruction preserves renal function

The incidence of congenital hydronephrosis is approximately 1% and is often associated with renal insufficiency. It is unknown whether early release is essential to prevent deterioration of renal function. Rats were subjected to partial unilateral ureteral obstruction (PUUO) on postnatal day 2. The obstruction was left in place or released after 1 or 4 wk. Renal blood flow (RBF) and kidney size were measured sequentially over 24 wk using MRI. In rats in which the obstruction was left in place, RBF of the obstructed kidney was progressively reduced to 0.92 +/- 0.17 vs. 1.79 +/- 0.12 ml.min(-1).100 g body wt(-1) (P < 0.05) after 24 wk. Similarly, glomerular filtration rate of the obstructed kidney was severely reduced at 24 wk: 172 +/- 36 vs. 306 +/- 42 microl.min(-1).100 g body wt(-1) (P < 0.05). These changes were preceded by development of severe hydronephrosis and obstructive nephropathy with a reduction in total protein content: 45 +/- 3 vs. 58 +/- 4 mg/kidney. Moreover, nonreleased PUUO caused a marked natriuresis (0.32 +/- 0.07 vs. 0.11 +/- 0.02 micromol.min(-1).100 g body wt(-1), P < 0.05) and impaired solute free water reabsorption (0.47 +/- 0.16 vs. 2.71 +/- 0.67 microl.min(-1).100 g body wt(-1), P < 0.05), consistent with a significant downregulation of Na-K-ATPase to 62 +/- 7%, aquaporin-1 to 53 +/- 3%, and aquaporin-3 to 53 +/- 7% of sham levels. Release after 1 wk completely prevented development of hydronephrosis, reduction in RBF and glomerular filtration rate, and downregulation of renal transport proteins, whereas release after 4 wk had no effect. These results suggest that early release of neonatal obstruction provides dramatically better protection of renal function than release of obstruction after the maturation process is completed.