LONG-TERM BLADDER DYSFUNCTION AND RENAL FUNCTION IN BOYS WITH POSTERIOR URETHRAL VALVES BASED ON URODYNAMIC FINDINGS

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.

A grading system for evaluation of bladder trabeculation

PURPOSE

To establish a parameter-based grading system for evaluating bladder trabeculation (BT).

MATERIALS AND METHODS

A retrospective analysis was conducted on children diagnosed with posterior urethral valve (PUV) or neurogenic bladder (NB) who underwent voiding cystourethrogram (VCUG), urodynamic testing, and urological ultrasonography between January 2016 and October 2022. Cases involving urologic surgery, secondary bladder pathology, and an interval of more than 12 months between examinations were excluded. A parameter named Bladder Dispersion (BD) was calculated through fluoroscopic images, and the grading system was developed as follows: BD < 40 (Grade 0), 40 ≤ BD < 60 (Grade 1), 60 ≤ BD < 90 (Grade 2), BD ≥ 90 (Grade 3). Grades 0-1 were classified as low-risk group, while grades 2-3 were classified as high-risk group. Analysis of variance, Kruskal-Wallis test, and Chi-square test were performed to compare urodynamic results and complications across different grades and groups.

RESULTS

A total of 74 patients were eligible to participate, which included 46 boys (62.2%) and 28 girls (37.8%), the mean age was 75.18 ± 48.39 months. Among them, 11 (14.9%) were PUV, 50 (67.6%) were NB, and 13 (17.5%) were PUV and NB. Significant differences were observed in maximum detrusor pressure, post-void residual urine ratio, and compliance among grades 0-3. Severe hydronephrosis and histories of urinary tract infection were more prevalent in the high-risk group.

CONCLUSION

A reliable grading system with objective standards was proposed which could aid in the assessment of BT severity.

Posterior urethral valves, pressure pop-offs, and kidney function: systematic review and meta-analysis

PURPOSE

To determine the role of pressure pop-off mechanisms, including vesicoureteral reflux and renal dysplasia (VURD) syndrome, in determining long-term kidney outcomes in boys with posterior urethral valves (PUV).

METHODS

A systematic search was performed in December 2022. Descriptive and comparative studies with a defined pressure pop-off group were included. Assessed outcomes included end-stage renal disease (ESRD), kidney insufficiency (defined as chronic kidney disease [CKD] stage 3 + or SCr > 1.5 mg/dL), and kidney function. Pooled proportions and relative risks (RR) with 95% confidence intervals (CI) were extrapolated from available data for quantitative synthesis. Random-effects meta-analyses were performed according to the study design and techniques. The risk of bias was assessed with the QUIPS tool and GRADE quality of evidence. The systematic review was prospectively registered on PROSPERO (CRD42022372352).

RESULTS

A total of 15 studies describing 185 patients with a median follow-up of 6.8 years were included. By the last follow-up, overall effect estimates demonstrate the prevalence of CKD and ESRD to be 15.2% and 4.1%, respectively. There was no significant difference in the risk of ESRD in patients with pop-off compared to no pop-off patients [RR 0.34, 95%CI 0.12, 1.10; p = 0.07]. There was a significantly reduced risk for kidney insufficiency in boys with pop-off [RR 0.57, 95%CI 0.34, 0.97; p = 0.04], but this protective effect was not re-demonstrated after excluding studies with inadequate reporting of CKD outcomes [RR 0.63, 95%CI 0.36, 1.10; p = 0.10]. Included study quality was low, with 6 studies having moderate risk and 9 having a high risk of bias.

CONCLUSIONS

Pop-off mechanisms may be associated with reducing the risk of kidney insufficiency, but current certainty in the evidence is low. Further research is warranted to investigate sources of heterogeneity and long-term sequelae in pressure pop-offs.

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.

Posterior urethral morphology on initial voiding cystourethrogram correlates to early renal outcomes in infants with posterior urethral valves

INTRODUCTION

Posterior urethral valves (PUV) is a leading cause of chronic renal failure in childhood. Bladder and posterior urethral deformity in infants with PUV are highly variable on initial voiding cystourethrogram (VCUG). Some types of deformity may be more important than others in determining the severity of the condition. Identification of specific VCUG features may allow for a simple, early screening assessment for patients.

OBJECTIVE

Determine whether morphologic features on the initial VCUG correlate to renal outcomes as measured by the creatinine nadir in the first year after ablation.

METHODS

Children with PUV treated by primary valve ablation before 12 months old and followed >1 year were identified. Initial diagnostic VCUG was evaluated for the bladder height to width ratio (HW-B), posterior urethral height to width ratio (HW-PU), and posterior-anterior urethral ratio (PA-UR). A trabeculation grade was assigned by three pediatric urologists, and reflux was noted. Univariable analyses with chi-square and t-test were used to compare bladder and posterior urethral morphology factors among those who obtained a creatinine nadir <0.8 or ≥0.8 mg/dL in the first year after ablation. Linear regression was performed to correlate morphology values with true creatinine nadir.

RESULTS

A total of 120 boys were ablated at mean age of 40.5 days (range 0-342) and followed for 5.9 years (± 3.85). Among these, 21 (17.5%) had a creatinine nadir ≥0.8 mg/dL. Mean overall HW-B and mean PA-UR were not significantly different between those with creatinine nadir <0.8 versus ≥0.8 mg/dL. Bladder trabeculation grade was not associated with creatinine nadir. For the entire cohort, only the difference in HW-PU was statistically significant between creatinine nadir groups with a much higher ratio among those with a nadir ≥0.8 (p < 0.001). Linear regression demonstrated a significant positive correlation between the HW-PU and creatinine nadir (R 2 = 0.097, p = 0.002). The presence of bilateral reflux is significantly associated with creatinine nadir ≥0.8 mg/dL (p = 0.001).

DISCUSSION

We investigate for the first time the association of morphology features on the initial VCUG with renal outcome in PUV patients. Posterior urethral deformity as quantified by a higher HW-PU ratio is significantly correlated with a higher creatinine nadir, whereas measured bladder morphology metrics are not. HW-PU may be an indirect measure of the severity of obstruction in posterior urethral valves.

CONCLUSION

The HW-PU appears to be a meaningful early morphologic metric for renal outcome.

Urodynamic assessment in the management of the child's posterior urethral valves

BACKGROUND

Bladder dysfunction may be associated with valves of the posterior urethra. Their evaluation by urodynamic assessment is an important parameter for the therapeutic management. The objective of our study was to study the contribution of urodynamic assessment in the management of valves of the posterior urethra of the child.

METHODS

Our study was descriptive, retrospective, involving 43 children with posterior urethral valves (PUV), followed at the pediatric ward at Charles Nicolle Hospital in Tunis from January 1995 to December 2015. All the children had an urodynamic assessment after valves of the posterior urethra treatment.

RESULTS

The mean age was 15.8 months. Preoperatively, creatinine clearance was below 60 ml / min in 32 patients (74%). The worsening of renal function was noted in 32 (74%). A significant post-voiding residue proved in 34 patients (79%). Cystometry revealed a hypo compliant bladder in 24 (56%), low bladder capacity in 42% of cases; a hypertonic detrusor in 37% of cases. Bladder sphincter dyssynergia was diagnosed in 6 patients. Like urodynamic assessment data, bladder enlargement associated with a Mitrofanoff-type shunt was indicated and performed in 3 patients (7%).

CONCLUSION

Through our study, the urodynamic profile made it possible to specify the type of vesico-sphincter dysfunctions persistent in patients operated for PUV, and subsequently to adapt the therapeutic conduct in these patients. Given the lack of management and the consequences on the health of the child as well as on his quality of life, reflections on the preventive and therapeutic approach after PUV treatment are necessary.

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.

The posterior urethral valves revisited: embryological correlation, clinical classification, and risk stratification of the spectrum

Background

The diagnosis of posterior urethral valves (PUV) encompasses a vast spectrum of disease with variable severity and clinical features. It is vital to understand the extent of developmental insult and to define the different distinct entities grouped together under the diagnostic umbrella of PUV. This would help to determine the severity of the disease, enable better prognostication, and optimize therapy. The objective of this study is to analyze the variable features of PUV and correlate the different manifestations with the embryological development of the urinary system. The possible developmental basis of anomalies in PUV is analyzed, as recognition of the underlying defect would help to determine the severity of the disease. A clinical classification and a risk stratification approach encompassing the spectrum of PUV is proposed, to help define diagnosis and guide prognosis. A combined retrospective and prospective analysis of cases diagnosed as PUV at the tertiary teaching institute over a 5-year period from July 2014 to July 2019 was done. The outcome of selected cases was analyzed, based on the risk group stratification.

Results

The incidence of major complications during follow-up in each risk group was assessed individually and found to be highest in the high-risk group (92%), which was significantly higher than the other groups. The intermediate risk group was found to have a complication rate of 38%, while the low-risk group had only 12.5% complication rate. The three key concepts addressed in this study pertain to the embryological basis of PUV, the necessity of a clinical subdivision of patients, and the possibility of risk stratification based on clinical criteria. The limited review of institutional series is added to highlight the method of risk stratification and its probable utility.

Conclusions

The most critical factors to be accounted for in the diagnosis and management of PUV are the definition of disease severity, recognition of systemic complications, and identification of children at risk of progression to ESRD. The proposed developmental defect analysis, description of PUV sequence, clinical classification, and risk stratification approach are only the means to this end of segregating patient groups within the diagnostic spectrum.

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.

Consensus on the Management of Posterior Urethral Valves from Antenatal Period to Puberty

The need for successful management of posterior urethral valves always captivates the minds of pediatric surgeons. Its success, however, depends on several factors ranging from prenatal preservation of upper tracts to postoperative pharmacological compliance. Regardless of measures available, some cases do not respond and progress to end stage. The management depends on several issues ranging from age and severity at presentation to long-term follow-up and prevention of secondary renal damage and managing valve bladder syndrome. This article is based on a consensus to the set of questionnaires, prepared by research section of Indian Association of Paediatric Surgeons and discussed by experienced pediatric surgeons based in different institutions in the country. Standard operating procedures for conducting a voiding cystourethrogram and cystoscopy were formulated. Age-wise contrast dosage was calculated for ready reference. Current evidence from literature was also reviewed and included to complete the topic.

Long-term outcomes of kidney and bladder function in patients with a posterior urethral valve

We investigated long-term functional changes in the kidney and bladder of patients with posterior urethral valve (PUV) who underwent fetal intervention or postnatal surgery.We retrospectively reviewed the medical records of 28 consecutive patients treated for PUV at our institution. Detailed data on medical and surgical histories, particularly on pre- and postnatal treatment modality, including fetal vesicoamniotic shunt, endoscopic valve ablation, and vesicostomy, were collected and analyzed. Long-term renal function was evaluated based on serum levels of creatinine (sCr), estimated glomerular filtration rate (eGFR), and renal scans. Voiding function was evaluated in urodynamic tests.Vesicoamniotic shunting was performed in 12 (42.8%) patients. Although the mean initial sCr was significantly higher in patients in whom a fetal shunt was placed than in others (2.04 vs 1.17 mg/L, P = .038), the sCr at long-term follow-up was not significantly different between them (0.64 vs 0.40 mg/L, P = .186). The mean maximum detrusor pressure was significantly lower in patients with a fetal shunt than in others (37.7 vs 73.0 cm H2O, P = .019). Postnatal vesicostomy was performed in 14 patients, and primary valve ablation was performed in 13 patients. The mean initial sCr was higher in patients in the vesicostomy group than in the primary valve ablation group (2.08 vs 0.86 mg/L, P = .014). However, no significant differences were found in sCr (0.9 vs 0.3 mg/L, P = .252) or GFR (59.1 vs 68.5 mL/min/1.73 m, P = .338) at long-term follow-up. Bladder capacity was greater and residual urine volume was less in the vesicostomy group than in the primary valve ablation group, but without statistical significance.Vesicostomy is more beneficial in the recovery of renal function and is not inferior in terms of bladder function, even in patients with severe PUV disorder. It is a reliable surgical option that can spare renal function and guarantee adequate bladder function in the long term.

Outcome of pediatric renal transplantation in urological versus non-urological causes of end stage renal disease: Does it matter?

INTRODUCTION

Causes for end stage renal disease (ESRD) in children can be categorized into urological causes or non-urological causes. We sought to compare the outcomes of urological and non-urological causes of ESRD in children.

METHODS

Patients were divided into two groups: urological causes of ESRD versus non-urological causes of ESRD. All patients and donors had at least 6 months of follow-up. The main outcomes included the effect on complications and renal function. Comparisons were carried out using the chi-square test or the Student t-test. Multivariate logistic regression analysis was used to define the effect of different variables on the outcome of renal transplantation (Table).

RESULTS

Our study included 123 patients, 91 males. The mean age was 9 years and mean follow up was 46 months. Two-thirds of the patients had non-urological causes of ESRD. Overall survival was 100%, and only one patient needed a graft nephrectomy 3 months after the transplant. The mean estimated glomerular filtration rate was 117 mL/min, and did not differ significantly between the two groups (p = 0.13). Multivariable regression showed that female gender (OR 8.7, 95% CI 2.9-26, p = 0 0.0001) was associated with better renal function, while having a urological cause of ESRD (OR 0.28, CI 0.08-0.98, p = 0 0.05) was associated with worse renal function. Non-urological causes of ESRD were significantly less likely to develop complications following renal transplantation (OR 0.28, CI 0.09-0.89, p = 0 0.03).

CONCLUSION

Female patients with non-urological causes of ESRD are more likely to have better long-term renal functions, and less liable to develop complications following renal transplant.

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).

Trends in Urologic Indications for Pediatric Renal Transplantation Over a 27-Year-period United Network for Organ Sharing (UNOS) Database

OBJECTIVE

To elucidate the trends in urologic causes for renal transplant in the pediatric population using a national database. Little is known about the specific pediatric urologic conditions and resultant trends that precede renal transplantation.

MATERIAL AND METHODS

We reviewed the United Network for Organ Sharing (UNOS) database for pediatric patients (<18 years old) who underwent renal transplantation from January 1988 to September 2015. We included those patients who received a renal transplant because of a urologic condition.

RESULTS

Over 27 years, 7291 of 20,213 children (36%) underwent renal transplant secondary to a urologic condition. The 2 most common indications were hypoplasia/dysplasia/dysgenesis/agenesis (HDDA, 35.1%) and congenital obstructive uropathy (COU, 25.7%). The incidence of COU has increased from 18% to 30%, and the incidence of Wilms tumor has remained relatively consistent at 1.8% per year. In addition, 68% of all urologic renal transplants were performed in men compared with women. However, a higher percentage of women required transplantation because of Wilms tumor (3.1% vs 1.2%) and chronic pyelonephritis (17.6% vs 7.9%). Overall, the majority of patients (61.5%) who underwent renal transplantation were white, 18.8% Hispanic, and 15.3% black.

CONCLUSION

HDDA and COU consistently have been the most common urologic indications for renal transplantation. Both are the leading causes in men, whereas HDDA and chronic pyelonephritis are predominant in women. Higher rate of renal transplant during the ages of 11-17 years is suggestive of increased burden on poorly functioning kidneys during times of adolescent growth.

Chronic kidney disease in the neonate: etiologies, management, and outcomes

Neonatal chronic kidney disease (CKD) occurs with an estimated incidence of 1 in 10,000 live births, whereas the incidence of neonatal end-stage renal disease (ESRD) is about 7.1 per million age-related population. The most frequent etiologies are renal hypoplasia/dysplasia, posterior urethral valves, and other congenital anomalies of the kidney and urinary tract. Other etiologies include polycystic kidney disease, cortical necrosis, and renal vascular thrombosis. Management of CKD focuses primarily on replacing renal functions such as erythropoietin, 1,25-hydroxylation of vitamin D, electrolyte homeostasis/excretion, and, in ESRD, waste product removal. Nutrition and growth monitoring are of utmost importance, with the majority of ESRD infants requiring gastrostomy tube for nutrition. Outcomes of neonates (<31 days) started on dialysis continue to improve, with large cohort studies showing 2-3-year survival rates of 79-81%. As in other neonatal disciplines, the gestational age and size limits for safe provision of dialysis continue to decrease.

Outcomes of living donor renal transplantation in children with lower urinary tract dysfunction: a comparative retrospective study

OBJECTIVES

To compare outcomes of renal transplantation (RTx) in children with end-stage renal disease (ESRD) resulting from lower urinary tract dysfunction (LUTD) vs other causes.

PATIENTS AND METHODS

A database of children (<18 years old) who underwent RTx between May 2008 and April 2012 was reviewed. Patients were divided into those with LUTD (group A, n = 29) and those with other causes of ESRD (group B, n = 74). RTx was performed after achieving low intravesical pressure (<30 cmH2 O) with adequate bladder capacity and drainage. The groups were compared using Student's t-test, Mann-Whitney, chi-squared or exact tests. Graft survival rates (GSRs) were evaluated using Kaplan-Meier curves and the log-rank test.

RESULTS

The mean ± sd (range) age of the study cohort was 5.05 ± 12.4 (2.2-18) years. Causes of LUTD were posterior urethral valve (PUV; 41.4%), vesico-ureteric reflux (VUR; 37.9%), neurogenic bladder (10.3%), prune belly syndrome (3.4%), obstructive megaureter (3.4%) and urethral stricture disease (3.4%). There was no significant difference in age, dialysis duration or donor type. In group A, 25 of the 29 patients (86.2%) underwent ≥1 surgery to optimize the urinary tract for allograft. Pretransplant nephrectomy was performed in 15 of the 29 patients (51.7%), PUV ablation in nine patients (31%) and ileocystoplasty in four patients (13.7%). The mean ± sd follow-up was 4.52 ± 1.55 and 4.07 ± 1.27 years in groups A and B, respectively. There was no significant difference in creatinine and eGFR between the groups at different points of follow-up. The GSRs at the end of the study were 93.1 and 91.1% in groups A and B, respectively (P = 1.00). According to Kaplan-Meier survival curves, there was no significant difference in the GSR between the groups using the log-rank test (P = 0.503). No graft was lost as a result of urological complications. In group B, one child died from septicaemia. The rate of urinary tract infections was 24 and 12% in groups A and B, respectively, but was not significant. No significant difference was found between the groups with regard to the incidence of post-transplantation hydronephrosis. Of the 22 patients who had hydronephrosis after transplantation, three were complicated by UTI. Injection of bulking agents was required in two patients for treatment of grade 3 VUR. In the third patient, augmentation cystoplasty was needed.

CONCLUSION

Acceptable graft function, survival and UTI rates can be achieved in children with ESRD attributable to LUTD. Thorough assessment and optimization of LUT, together with close follow-up, are key for successful RTx.

[Urodynamic profile of voiding disorders persisting after treatment of posterior urethral valve]

PURPOSE

Posterior urethral valves (PUV) are the most common cause of bladder outlet obstruction in infancy that impairs renal and bladder function.

MATERIAL AND METHODS

We realize a retrospective study and examined 35 boys with urinary disorders post-treatment of PUV, seen at the urodynamic consultation.

RESULTS

The mean age: 7.56 years, urinary problems are dominated by recurrent urinary tract infections and urinary leakage, morphological assessment is marked by the constant expansion of the urinary tract and bladder, 18 children have end-stage renal disease of which 8 are candidates for transplantation. About urodynamic, the uroflowmetry with measure of post-void urine residue: dysuria with significant residual urine in 14 children; for cystometry, 20 children with bladder hyperactivity, 9 bladders are hypotonic hypoactive with high capacity, 6 explorations are normal.

CONCLUSION

Urodynamic explorations are all interest when voiding symptoms persist after endoscopic section valves and despite a good radiological result.

Best practice in the assessment of bladder function in infants

The purpose of this article is to review normal developmental bladder physiology in infants and bladder dysfunction in conditions such as neurogenic bladder, posterior urethral valves and high grade vesicoureteric reflux. We contrast the classical concept that bladder function in nontoilet-trained children is thought to be 'reflexive' or 'uninhibited', with the results of more recent research showing that infants most commonly have a stable detrusor. The infant bladder is physiologically distinct from the state seen in older children or adults. The voiding pattern of the infant is characterized by an interrupted voiding stream due to lack of proper urinary sphincter relaxation during voiding. This is called physiologic detrusor sphincter dyscoordination and is different from the pathologic 'detrusor sphincter dyssynergy' seen in patients with neurogenic bladder. Urodynamic abnormalities in neonates born with spina bifida are common and depend on the level and severity of the spinal cord malformation. Upper neuron lesions most commonly lead to an overactive bladder with or without detrusor sphincter dyssynergy while a lower neuron lesion is associated with an acontractile detrusor with possible denervation of the external urinary sphincter. In infants with neurogenic bladder, the role of 'early prophylactic treatment (clean intermittent catheterization and anticholinergics)' versus initial 'watchful waiting and treatment as needed' is still controversial and needs more research. Many urodynamic-based interventions have been suggested in patients with posterior urethral valves and are currently under scrutiny, but their impact on the long-term outcome of the upper and lower urinary tract is still unknown. Cumulative data suggest that there is no benefit to early intervention regarding bladder function in infants with high-grade vesicoureteric reflux.

Long-term consequences of posterior urethral valves

Posterior urethral valves (PUV) are the most common congenital cause of bladder outlet obstruction in infancy, and it is the effect of this obstruction on the bladder and the kidneys that will decide a patient's prognosis. With the improvements in diagnosis and treatments, what was previously a poor prognosis for boys with PUV has improved, and more patients will encounter the long-term sequelae of PUV during puberty and adulthood. In these patients the long-term prognosis in terms of renal and bladder function and fertility, as well as the risk of malignancy in those whose bladders were augmented with gastrointestinal segments, is still a matter of great concern and all of these topics will be discussed in this article.

Is a closed bladder neck on preoperative videourodynamic studies an important factor for continence following augmentation ileocystoplasty in myelodysplastic patients?

PURPOSE

The aim of this study is to evaluate the importance of a closed bladder neck during videourodynamic (VUDE) studies in relation to urinary continence following augmentation ileocystoplasty in myelodysplastic patients.

MATERIALS AND METHODS

We retrospectively reviewed the records of 24 myelodysplastic patients who underwent augmentation ileocystoplasty, using a standard technique. All patients had a closed bladder neck during preoperative VUDE studies. Their charts, imaging studies and VUDE data before and after surgery were analyzed. The mean follow-up after augmentation ileocystoplasty was 8.4 years.

RESULTS

The overall incidence of urinary incontinence following the augmentation ileocystoplasty was 12.5%. Continence was achieved in 21 of 24 (87.5%) patients without additional outlet procedures. No significant upper tract changes developed. A clinically apparent tethered cord significantly hindered the achievement of continence. No significant correlation was found between the other videourodynamic parameters and obtaining continence.

CONCLUSIONS

Our study provides evidence that a coexisting cord tethering in this myelodysplastic group can affect bladder neck morphology and function, and subsequent continence.

What has changed in pediatric kidney transplantation in Turkey? Experience of an evolving center

INTRODUCTION

Reluctance to perform kidney transplantations on children is an ongoing problem in Turkey. Moreover, urological pathologies still constitute the largest portion of the underlying etiologies in chronic renal failure patients. Herein, we retrospective analyzed the data acquired from our pediatric renal transplantation patients and reviewed the registry of dialysis and transplantation data prepared by the Turkish Society of Nephrology.

MATERIAL AND METHODS

Forty-six living donor kidney transplantations were performed in children between 2008 and 2012. Seventeen of 46 (37%) transplantations were preemptive. The mean age at operation time was 10.8 ± 5 years. The mean patient weight was 31.3 ± 15.8 kg (range, 9.4 to 66.4 kg). A detailed urologic evaluation was performed for every child with an underlying lower urinary tract disease. One enterocystoplasty and 2 ureterocystoplasties were performed for augmentation of the bladder, simultaneously.

RESULTS

One-year death-censored graft survival and patient survival rates were 100% and 97.8%, respectively. The mean serum creatinine level was 0.86 ± 0.32 mg/dL (range, 0.3 to 1.8 mg/dL). None of the patients had vascular complications or acute tubular necrosis. One patient suffered graft-versus-host disease during the second month after renal transplantation and died with a functioning graft. In one patient with massive proteinuria detected after transplantation, recurrence of primary disease (focal segmental glomerulosclerosis) was considered and the patient was treated successfully with plasmapheresis. One child had an acute cellular rejection and was administered pulse steroid treatment.

CONCLUSION

Although challenging, all patients in all pediatric age groups can successfully be operated and managed. With careful surgical technique, close postoperative follow-up, and efforts by the experienced and respectful surgical teams in this country, we could change the negative trends toward perform kidney transplantation in the Turkish pediatric population.

Efficacy of bladder neck incision on urodynamic abnormalities in patients with posterior urethral valves

PURPOSE

This study aims to study the efficacy of simultaneous endoscopic bladder neck incision (BNI) and primary endoscopic valve incision (PEVI) in patients with posterior urethral valves (PUV).

MATERIALS AND METHODS

Nine PUV patients underwent PEVI and BNI over a year. They were compared to nine comparable historical controls that had undergone only PEVI. Trends in renal function tests, urodynamics and changes in the upper urinary tracts were evaluated after 3 months during which no pharmacotherapy was given.

RESULTS

The incidence of bladder dysfunction in the two groups was similar-55.5 % in case group and 66.6 % in control group. Hypocompliant, high-pressure bladder was the predominant cystometric finding in both groups. Three patients in the case group and two patients in the control group had high end infusion pressure (EIP) with poor compliance. Detrusor overactivity (DOA) was seen in 23.1 % patients in the case group as compared to 55.5 % patients in the control group (P = 0.3348). Five patients in both groups were later started on anticholinergics due to raised EIP, small capacity bladder and/or DOA.

CONCLUSION

Although BNI should theoretically improve the outcome of PUV patients, the current pilot study failed to demonstrate any significant difference. A larger sample size and longer follow-up are required to prove or disprove its efficacy.

Large-conductance calcium-activated potassium channel activity, as determined by whole-cell patch clamp recording, is decreased in urinary bladder smooth muscle cells from male rats with partial urethral obstruction

OBJECTIVES

To examine the effect of partial urethral obstruction (PUO) on bladder smooth muscle outward potassium current and the contribution of the large-conductance calcium-activated potassium (Maxi-K, BKCa) channel to this activity in smooth muscle cells isolated from bladders of sham-operated and PUO male rats using whole-cell patch clamp recording techniques. To determine the effect of PUO on the expression of the Maxi-K channel α and β1 subunits and in vitro detrusor contractility.

MATERIALS AND METHODS

Twenty adult male Sprague-Dawley rats were divided equally into two groups and subjected to surgical ligation of the urethra (PUO) or sham surgery (SHAM). After 2 weeks, the detrusors from PUO and SHAM rats were used for molecular analyses (mRNA and protein quantification of Maxi-K subunits) or organ bath contractility studies, or myocytes were isolated for conventional whole-cell patch clamp analyses.

RESULTS

PUO increased bladder mass 2.5-fold and detrusor strips exhibited a more tonic-type contraction and increased contractility compared with controls (SHAM). Iberiotoxin (300 nM) sensitive Maxi-K channel current comprised about 40% of the outward whole-cell current in SHAM bladders but only about 8% in PUO bladders. Expression of the α subunit of the Maxi-K channel was significantly decreased ~40% while the expression of the β1 subunit was increased ~2-fold at the mRNA level. The increase in β1 expression was confirmed by Western blotting.

CONCLUSIONS

Our findings show that obstruction of the rat bladder is associated with decreased Maxi-K channel activity of bladder smooth muscle cells, determined via direct current measurement. Increased expression of the β1 subunit points to a compensatory reaction to decreased Maxi-K channel activity. Maxi-K channel openers or gene therapy may therefore provide therapeutic benefit for the overactive bladder.

Reduction of cystometric bladder capacity and bladder compliance with time in patients with end-stage renal disease

BACKGROUND/PURPOSE

Reduced bladder capacity and compliance in patients with end-stage renal disease (ESRD) may affect storage and voiding function after kidney transplantation. This study evaluated the bladder capacity, compliance, and lower urinary tract dysfunction in ESRD patients with duration after dialysis and anuria.

MATERIALS AND METHODS

Adults with ESRD on kidney transplantation waiting list were consecutively enrolled. The survey items included videourodynamic study (VUDS), renal ultrasound, and cystoscopy. The analytical variables assessed included the duration of dialysis, the duration of anuria, cystometric bladder capacity and bladder compliance, voiding phases in VUDS, and cystoscopic findings.

RESULTS

A total of 62 patients with a mean dialysis duration of 58.9 ± 6.3 months were enrolled. The mean cystometric bladder capacity was 178 ± 14 mL and decreased significantly with duration of dialysis (p < 0.001). Anuria was diagnosed in 26 patients, and the mean cystometric bladder capacity decreased significantly with the duration of anuria (p = 0.002). Among the 26 patients with anuria, 16 had a poor bladder compliance. VUDS revealed abnormal storage function in 44 (71.0%) patients and bladder outlet obstruction due to bladder neck dysfunction or urethral narrowing in the voiding phase in 32 (51.6%). Abnormal cystoscopic findings were also noted in 30 (48.4%) patients.

CONCLUSION

Cystometric bladder capacity and bladder compliance decreased with longer duration of dialysis, and the presence of anuria contributed to further decreases in cystometric bladder capacity and bladder compliance. More than two-thirds of patients with ESRD had abnormal findings on VUDS.

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.

Surgical complications of posterior urethral valve ablation: 20 years experience

PURPOSE

The aim of the study was to report the surgical complications that may occur during or after primary ablation of posterior urethral valve (PUV) in a large number of cases treated using different modalities.

MATERIALS AND METHODS

We retrospectively reviewed a database of 291 patients with PUV treated by primary valve ablation from 2 separate centers between 1987 and 2006. Primary valve ablation was performed in all patients regardless of serum creatinine level or upper tract configuration. A hot loop resectoscope was used in 122 patients, cold knife urethrotome in 108, a hook diathermy electrode in 18, a diathermy coagulation bugbee electrode in 20, whereas stripping using a Fogarty catheter was performed in 23.

RESULTS

The follow-up duration ranged from 1.5 to 20 years (median, 6.5). Early postoperative complications occurred in 22 patients (7.5%). The most common complication was urinary retention in 16 patients (5.5%). Urinary extravasations occurred in 3 cases, significant hematuria from urethral bleeding occurred in 2, and obstructive anuria developed in 1 patient. Most of cases were treated conservatively. Urethral strictures developed in 6 patients (2%) mainly after endoscopic loop resection (4/6). All were treated by visual internal urethrotomy and urethral dilatation with successful results without the need of open urethroplasty.

CONCLUSIONS

Primary valve ablation seems to be safe and is associated with low rate of postoperative complications. All the complications could be treated conservatively. Urethral stricture may occur after valve ablation in a minority of cases and can be successfully treated endoscopically. Loop resection is associated with more strictures.

CONGENITAL URINARY BLADDER OUTLET OBSTRUCTION

The term congenital ‘bladder outlet obstruction (BOO)’ describes the collection of conditions in which the normal, urethral egress of urine from the fetal bladder is impaired. The term is interchangeable with fetal ‘lower urinary tract obstruction’, as used by other authors. After considering normal urinary tract embryology, we describe the epidemiology of congenital BOO and the primary anatomical disorders associated with it. We then proceed to describe its fetal and postnatal clinical manifestations and then consider therapies and interventions which have been used to manage the condition. We not only focus on urethral and bladder disease with constitutes BOO itself, but also describe associated kidney disorders which, via chronic renal excretory failure, are important causes of morbidity. Rather than provide an exhaustive review, we emphasise studies published in the last decade, and therefore readers are referred to other reviews citing numerous earlier references.

Validation of initial serum creatinine as a predictive factor for development of end stage renal disease in posterior urethral valves

OBJECTIVE

The aim of this study was to determine the value of initial serum creatinine in prediction of End-stage renal disease (ESRD) in children with posterior urethral valves PUV.

METHODS

In this retrospective study, patients diagnosed with PUV admitted in Aliasghar Children's Hospital in Tehran, Iran from 1991 through 2001 were studied. Based on the development of ESRD (need for dialysis) they were classified in two groups and their demographics, initial presentations, laboratory data, imaging findings and outcomes were reviewed and compared.

RESULTS

Thirty six male patients with PUV, treated with valve ablation (13), vesicostomy (13), or high ureterostomy (10) were followed for developing ESRD. Sixteen of the 36 patients developed ESRD at their last follow-up. There was no significant difference in age at initial presentation, presence of urinary tract infections, incidence of vesicoureteral reflux, renal dysplasia or type of primary surgical intervention between the patients with or without ESRD. Patients who progressed to ESRD had serum creatinine concentration > 1.0 mg/dl at diagnosis as compared to those without ESRD (P = 0.001).

CONCLUSION

Initial serum creatinine is a valuable factor for prediction of renal outcome in patients with PUV.

Renal transplantation in children with lower urinary tract dysfunction of different origin: a single-center experience

INTRODUCTION

Renal transplantation in patients with lower urinary tract dysfunction (LUTD) of various origins is a challenging issue in the field of pediatric transplantation. We report our single-center experience to evaluate patient and graft survivals as well as the risks of the surgery and immunosuppressive therapy.

PATIENTS AND METHODS

Among 70 pediatric transplant patients, 11 displayed severe LUTD. Videourodynamic tests were performed on all patients preoperatively as well as postoperatively if required. The cause of urologic disorders were neurogenic bladder (n = 5) and urethral valves (n = 6). Clean intermittent catheterization (CIC) was needed in six patients to empty the bladder. To achieve a low-pressure reservoir with adequate capacity pretransplantation augmentation ileocystoplasty was created in four patients and gastrocystoplasty in one patient. Three of the patients received kidneys from cadaveric and eight from living donors. All patients were treated with calcineurin-based immunosuppressive therapy.

RESULTS

The mean age at transplantation was 15 +/- 4.7 years. The median follow-up after transplantation was 36 months (6 to 62 months). At their last visit the median creatinine level was 0.95 mg/dL (0.8 to 2.4 mg/dL). Three patients had recurrent symptomatic urinary tract infections who had augmented bladder on CIC. One patient with ileocystoplasty who developed urinary leak and ureteral stricture in the early postoperative period was treated by an antegrade J stent.

CONCLUSION

Severe LUTD carried high risks for the grafted kidney. However, our data suggested that renal transplantation is a safe and effective treatment modality, if the underlying urologic diseases properly managed during the transplantation course. Since surgery and follow-up is more complicated, patient compliance and experience of transplantation team have significant impacts on outcomes.

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.

Radiotelemetered urodynamics of obstructed ovine fetal bladders: correlations with ex vivo cystometry and renal histopathology

OBJECTIVE

To test the hypothesis that fetal bladder outlet obstruction (BOO) in sheep causes abnormal urodynamics correlating with the initiation of renal pathology, as most boys with posterior urethral valves (PUV) have bladder dysfunction when assessed after birth.

MATERIALS AND METHODS

Male ovine fetuses at 94 days of gestation were assigned to BOO (four) or sham control (five) groups. In BOO fetuses, radiotelemetry catheters were inserted transurachally and intraperitoneally, and the urethra was partly occluded. In two sham controls catheters were inserted directly through the bladder wall; the remaining three had sham surgery only. Radiotelemetered cystometry was recorded daily where possible. At the end of the experiment (9 days), ex vivo cystometry, bladder contractility studies and renal tract histology were assessed.

RESULTS

Ultrasonography showed dilated renal tracts only in BOO fetuses; three of four BOO fetuses had renal cortical cysts. The control fetuses with bladder catheters died in utero, so urodynamics were recorded only in fetuses with BOO. The baseline filling/storage detrusor pressures increased slightly (by a mean of 5 mmHg) during the first 4 days of BOO, thereafter returning to those at the outset. There were marked changes in the patterns of bladder activity from 1 to 9 days. The frequency and duration of 'voiding' increased; as such the higher sustained pressures of emptying activity were progressively extended and the periods of low pressure filling/storage accordingly shortened. The patterns among individual fetuses with BOO were not substantially different, except that the one with the non-cystic kidneys had a more moderate frequency and duration of voiding. Ex vivo compliance and contractility showed no consistent differences in detrusor compliance or contractility between BOO and sham bladders.

CONCLUSION

In this fetal model of PUV, there was a progressive increase in the duration and frequency of sustained elevated 'voiding' pressures, with no change in bladder compliance. Fetal kidneys were sensitive to these altered dynamics, with the formation of cortical cysts by 9 days after initiating BOO.

Posterior urethral valve: Outcome of antenatal intervention

INTRODUCTION AND AIM

Antenatal treatment of obstructive uropathy, although widely performed, remains controversial. This study evaluated the long-term outcome of managing patients with posterior urethral valves (PUV), highlighting the effect of antenatal vesicoamniotic shunt placement for patients who underwent fetal surgery.

METHODS

The medical records of 58 patients with PUV were retrospectively reviewed from June 1998 to June 2004. On the basis of prenatal assessment of sonographic findings and serial urinary electrolytes and protein measurements, patients were divided into two groups: group 1 comprised patients who had antenatal vesicoamniotic shunt placement whereas group 2 comprised patients who underwent postnatal surgical correction of PUV. Their outcomes and long-term results were evaluated.

RESULTS

Patients were followed up from 6 months to 6(1/2) years (mean 3.9 years). Group 1 included 12 patients who had vesicoamniotic shunt placement and were confirmed postnatally to have PUV. Four patients out of 12 died (33.3%); three out of the eight living patients had perinatal complications. Of the eight living patients, three (37.5%) underwent valve ablation and five (62.5%) underwent urinary diversion (three vesicostomies and two cutaneous ureterostomies). Renal function returned to normal in only four patients (50%). Radiological abnormalities (hydronephrosis and/or reflux) resolved in three (37.5%) patients, was downgraded in one (12.5%) patient and persisted in four patients (50%). Group 2 included 46 patients who were treated postnatally. Thirty-five patients (76%) underwent primary valve ablation, while 11 (24%) underwent urinary diversion (seven vesicostomies, four cutaneous ureterostomy and one pyelostomy). Renal function returned to normal in all patients who underwent valve ablation, except in three, while renal function returned to normal in only three of 11 patients who underwent urinary diversion. Radiological hydronephrosis and/or reflux resolved in 28 patients (60.9%), was downgraded in six patients (13%) and persisted in 12 patients (26.1%).

CONCLUSIONS

Antenatal vesicoamniotic shunt placement makes no difference to the outcome and long-term results of patients with PUV and debate about its efficacy on renal outcome remains. Primary valve ablation is the keystone of treatment for patients with PUV that might achieve the primary goal of nephron preservation. The lowest creatinine concentration in the first year of life is the most appropriate predictor of future renal function.

Significance of age-specific creatinine levels at presentation in posterior urethral valve patients

OBJECTIVE

Determination of prognostic factors is of great importance in decision making on therapies and informing parents about the probable outcome of disease. The present study aims to evaluate and assess the prognostic factors in posterior urethral valve (PUV) patients.

MATERIALS AND METHODS

The data of 68 patients treated between 1996 and 2004 were evaluated retrospectively. The mean age at diagnosis was 36.4 months. The serum creatinine levels were standardized using the age-specific creatinine reference (ASCR) levels. The age at diagnosis, clinical presentation, initial serum creatinine, method of treatment, presence of vesicoureteral reflux (VUR) and hydroureteronephrosis (HUN), all of which may effect the prognosis, were evaluated.

RESULTS

The analysis revealed that, of the 36 patients whose initial serum creatinine levels were within ASCR, only one (2.8%) had a final serum creatinine higher than ASCR values. In contrast, of the 32 patients whose initial serum creatinine levels were not within ASCR, 19 (59.4%) had final serum creatinine levels higher than ASCR (P<0.001). The distribution of final serum creatinine according to treatment method, presence of UTI before treatment and age at diagnosis was not statistically significant; however, the difference in distribution for initial serum creatinine (P<0.001), mode of clinical presentation (0.016), presence of HUN (0.019) and state of VUR (0.037) before treatment was statistically significant.

CONCLUSION

Final outcome with regard to renal function in PUV patients is affected by bilateral VUR and most significantly by serum creatinine levels higher than ASCR.

Experimental short-term partial fetal bladder outflow obstruction: II. Compliance and contractility associated with urinary flow impairment

PURPOSE

Posterior urethral valves (PUV) is the commonest cause of congenital bladder outlet obstruction. Despite valve ablation in the neonatal period, up to 70% of patients develop renal failure by their teenage years, and progressive bladder dysfunction. This study forms part of a continuing project examining the relationship between severity and duration of obstruction and urinary tract dysfunction. Here is the assessed result of short-term (9-day) obstruction.

MATERIALS AND METHODS

Fourteen male fetal lambs at 75 days' gestation were assigned to one of three groups: urachal ligation, urachal ligation with partial urethral obstruction, sham-operated controls. Pregnancy proceeded for 9 days. At autopsy, filling cystometry was performed with the urinary tract in situ and the bladder harvested for nerve counts using PGP 9.5 immunohistochemistry, or in vitro measurement of contractile function.

RESULTS

Obstruction was associated with an increase in bladder:fetal weight ratio. Compliance was variable in the obstructed bladders, but the calculated wall stress per unit strain was either similar or less than controls. Nerve-mediated or agonist-induced contraction magnitude in tissue from obstructed bladders and nerve counts did not differ from controls.

CONCLUSIONS

Nine days of outflow obstruction at mid-gestation generated a bladder of increased weight but without evidence of contractile failure. An increase in bladder compliance as a function of bladder growth was observed even at this stage, and represents one of the initial responses to outflow tract obstruction.

Dysfunction of lower urinary tract in renal transplant children with nephrologic disease

OBJECTIVES

To investigate the relationship between dysfunction of the lower urinary tract after renal transplantation and renal transplant function in children with an underlying nephrologic disease.

METHODS

The research group consisted of 21 renal transplant children (12 girls and 9 boys, mean age 13.5 years, range 6 to 18) with an underlying nephrologic disease. To indicate renal transplant function, the calculated creatinine clearance rate (Ccr) according to Schwartz was used. The Ccr was measured at two points, 2 months after transplantation and at the moment of study. The average graft age was 34 months (range 5 to 85). The data on dysfunction of the lower urinary tract were gathered using a written questionnaire, frequency volume chart, free uroflowmetry, transabdominal ultrasonography, and medical records. To determine the relationship between the symptoms of dysfunction of the lower urinary tract and Ccr at the moment of study, we computed bivariate correlations and performed multivariate regression analyses in which the associations were studied while controlling for the Ccr 2 months after transplantation and graft age.

RESULTS

A sensation of incomplete emptying (P = 0.03), postvoid residual urine volume (P = 0.06), and urinary tract infection (P = 0.004) correlated negatively with the Ccr at the moment of study. These effects remained present (P = 0.07, P = 0.03, and P = 0.003, respectively) while controlling for graft age and the Ccr at 2 months after transplantation in the regression analysis.

CONCLUSIONS

The results of our study have shown that a postvoid residual urine volume and urinary tract infections after renal transplantation may result in renal transplant deterioration in children with an underlying nephrologic disease.

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.