Posterior Urethral Valve Patients Research Articles

Long-term Follow Up of Posterior Urethral Valve Patients and Predictors of Outcome, Cairo University Specialized Pediatric Hospital

Long-term Follow Up of Posterior Urethral Valve Patients and Predictors of Outcome, Cairo University Specialized Pediatric Hospital

Chronic Kidney Disease in Boys with Posterior Urethral Valves-Pathogenesis, Prognosis and Management.

Posterior urethral valves (PUV) are the most common form of lower urinary tract obstructions (LUTO). The valves can be surgically corrected postnatally; however, the impairment of kidney and bladder development is irreversible and has lifelong implications. Chronic kidney disease (CKD) and bladder dysfunction are frequent problems. Approximately 20% of PUV patients will reach end-stage kidney disease (ESKD). The subvesical obstruction in PUV leads to muscular hypertrophy and fibrotic remodelling in the bladder, which both impair its function. Kidney development is disturbed and results in dysplasia, hypoplasia, inflammation and renal fibrosis, which are hallmarks of CKD. The prognoses of PUV patients are based on prenatal and postnatal parameters. Prenatal parameters include signs of renal hypodysplasia in the analysis of fetal urine. Postnatally, the most robust predictor of PUV is the nadir serum creatinine after valve ablation. A value that is below 0.4 mg/dl implies a very low risk for ESKD, whereas a value above 0.85 mg/dl indicates beneficial kidney outcome. Experimental urinary markers such as MCP-1 and TGF-β, as well as microalbuminuria, indicate progression to CKD. Until now, prenatal intervention may improve survival but yields no renal benefit. The management of PUV patients includes control of bladder dysfunction and CKD treatment to slow down progression by controlling hypertension, proteinuria and infections. In kidney transplantation, aggressive bladder management is essential to ensure optimal graft survival.

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

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. Determine whether morphologic features on the initial VCUG correlate to renal outcomes as measured by the creatinine nadir in the first year after ablation. 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 ≥0.8mg/dL in the first year after ablation. Linear regression was performed to correlate morphology values with true creatinine nadir. 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 ≥0.8mg/dL. Mean overall HW-B and mean PA-UR were not significantly different between those with creatinine nadir <0.8 versus ≥0.8mg/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 ≥0.8mg/dL (p=0.001). 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. The HW-PU appears to be a meaningful early morphologic metric for renal outcome.

Outcome of boys with posterior urethral valves from a single tertiary hospital in Singapore.

Posterior urethral valve (PUV) is the most common congenital cause of bladder outflow obstruction in male infants. Despite timely treatment, renal damage can still occur in the long-term leading to chronic kidney disease (CKD). A retrospective review of all PUV patients in a single tertiary institution between April 1998 and July 2019 was conducted to analyze their presentations, management and outcomes. Long-term renal function, radiologic scans and somatic growth were evaluated. A total of 16 patients were included in this study. Two patients who defaulted all follow-ups were excluded. Seven patients (43.7%) presented in the antenatal period; four patients (25%) presented in the neonatal period and five patients (31.3%) presented in the post-neonatal period. Primary transurethral fulguration of valves was done in 13 patients, while three had vesicostomies as the primary procedure. Three patients had associated anterior urethral valves (AUV), which were treated endoscopically. Nine boys had additional procedures for diversion and undiversion, VUR, non-functioning kidney and clean intermittent catheterization. Ten patients had urodynamic studies performed, of which eight patients received anticholinergic therapy. Eleven patients had DMSA scans, of which three patients had a normal study and eight patients showed unilateral reduced function. Four patients were diagnosed with CKD on long-term follow-up duration over 5 years. All patients were shown to have good somatic growth. Patients with PUV can suffer from complications despite primary treatment. In our small cohort, a quarter of our patients developed CKD on follow-up. Thus, patients need long-term follow-up to optimize bladder and renal function.

Correlation of Urethral Ratio and Bladder Wall Thickness with Cystoscopic Findings in Posterior Urethral Valve Patients to Assess Residual Valves.

Introduction:Posterior urethral valve (PUV) is life threatening congenital anomaly of urinary tract. Aim of the study was to correlate urethral ratio (UR) and bladder wall thickness (BWT) with cystoscopic findings in PUV patients to assess residual valves and to validate UR as a diagnostic tool for residual valves. It also aimed to assess the utility of bladder wall thickness in diagnosis of residual valves.Materials and Methods:A total of 31 patients were included in the prospective study done from 2017 to 2019. Calculation of UR was done in oblique VCUG films by dividing maximum posterior and anterior urethral diameter without the catheter insitu. Measurement of BWT was done at dome and bladder neck at full distension with feeding tube insitu and was done at same volume in follow up. The procedure was repeated at 3 months follow up. The findings were compared with cystoscopic findings for the status of residual valves as gold standard. Each patient served as control for self in the study.Results:Median age of presentation was 1 years with range of 1day to 10 years. The most common complains at the time of presentation in our study was straining (35.48%) followed by antenatally diagnosed patients (25.81%) and recurrent UTI (19.36%). Pre fulguration median UR was 2.45. Post Fulguration median UR was 1.20. It showed a statistically significant reduction (p < 0.001) after fulguration. Pre fulguration median BWT was 4 mm. Post fulguration median BWT was 2.5 mm. BWT showed a statistically significant reduction (p < 0.001) after fulguration as well. ROC curve was plotted for UR and BWT. BWT more than 1.95 mm (sensitivity-80%) and UR more than 1.2 (sensitivity-70%) indicates residual valves.Conclusion:A step ladder approach including BWT, UR and check cystoscopy can serve as a new diagnostic algorithm for the assessment of residual valves thereby avoiding extra radiation and general anesthesia exposure.

Serum and urine periostin and cytokeratin-18 in children with congenital obstructive nephropathy.

Congenital obstructive nephropathy (CON) is one of the most common causes of chronic kidney disease in children. The aim of the study was to investigate serum and urine periostin and cytokeratin-18 (CK-18) in children with CON in relation to CON etiology, treatment, and kidney injury. We evaluated 81 children with CON secondary to ureteropelvic junction obstruction (UPJO), ureterovesical junction obstruction (UVJO), posterior urethral valves (PUV) and 60 controls. Neither biomarker demonstrated any relation to CON etiology. However, all patients showed significantly higher urine periostin (uPeriostin) and uPeriostin/Cr levels than the controls. Also, UVJO patients showed higher sCK-18 and uCK-18/Cr levels, and PUV patients showed higher uCK-18/Cr levels than the controls. Neither biomarker was found to have any relation to CON treatment. However, conservatively treated children and those before and after surgery showed significantly higher uPeriostin and uPeriostin/Cr levels than the controls. uPeriostin strongly correlated with differential renal function (DRF) < 40%. The ROC analysis demonstrated the best area under the curve (AUC) for uPeriostin (0.831) and uPeriostin/Cr (0.768), and low for sPeriostin (0.656) and uCK-18 (0.615) for detecting renal injury. In conclusion, although serum and urine periostin and CK-18 did not display any relation to etiology or the type of CON treatment, uPeriostin seems to be a useful tool for detecting renal injury in children with CON, especially due to its strong negative correlation with DRF < 40%.

Does Early Upper Tract Diversion and Delayed Undiversion in Megaureters Secondary to Severe Posterior Urethral Valves Lead to Better Renal Outcomes?

Background:There are conflicting reports for the management of severe posterior urethral valve (PUV) after ablation. The primary objective was to assess the renal outcomes using the estimated glomerular filtration rate (eGFR) and secondary outcomes in severe PUVs who underwent early partially diverting reduction ureterostomy (PDRU) and a delayed undiversion protocol.Materials and Methods:This 10-year retrospective study reviewed the records of 1094 boys with PUV, where severe PUV cases were treated with early PDRU (324 surgeries). We then analyzed those patients who completed the early diversion and delayed undiversion protocol. The long-term renal outcomes using eGFR and antero-posterior diameter (APD) were compared at various time points using appropriate statistical methods.Results:Of the 171 severe PUV patients who underwent PDRU, 31 completed undiversion and 26 (47 renal units) were analyzed after exclusions. The mean age (standard deviation) at presentation was 1.46 ± 4.1 months. Thirty-two units were refluxing and 15 were nonrefluxing megaureters. PDRU was closed at a mean age of 3.9 years and had a mean duration of follow-up of 6.4 years. The mean eGFR increased from a minimum of 10.78 ± 10.25 at baseline and remained stable at 28.69 ± 18.89 after closure of both stoma. Similarly, mean APD decreased from 12.07 ± 6.79 at the diagnosis to 7.00 ± 6.20. Three patients (3 renal units) required revision of the stoma for stenosis and 1 patient had a parastomal hernia that was repaired at the time of undiversion.Conclusions:In severe PUVs, early PDRU with delayed undiversion is a reliable surgical option that may ensure better renal outcomes in the long-term. Nonrefluxing renal units recover better than the refluxing. APD measurements also are shown to improve favorably.

Genome-Wide Survey for Microdeletions or -Duplications in 155 Patients with Lower Urinary Tract Obstructions (LUTO).

Lower urinary tract obstruction (LUTO) is, in most cases, caused by anatomical blockage of the bladder outlet. The most common form are posterior urethral valves (PUVs), a male-limited phenotype. Here, we surveyed the genome of 155 LUTO patients to identify disease-causing CNVs. Raw intensity data were collected for CNVs detected in LUTO patients and 4.392 healthy controls using CNVPartition, QuantiSNP and PennCNV. Overlapping CNVs between patients and controls were discarded. Additional filtering implicated CNV frequency in the database of genomic variants, gene content and final visual inspection detecting 37 ultra-rare CNVs. After, prioritization qPCR analysis confirmed 3 microduplications, all detected in PUV patients. One microduplication (5q23.2) occurred de novo in the two remaining microduplications found on chromosome 1p36.21 and 10q23.31. Parental DNA was not available for segregation analysis. All three duplications comprised 11 coding genes: four human specific lncRNA and one microRNA. Three coding genes (FBLIM1, SLC16A12, SNCAIP) and the microRNA MIR107 have previously been shown to be expressed in the developing urinary tract of mouse embryos. We propose that duplications, rare or de novo, contribute to PUV formation, a male-limited phenotype.

Outcome of PUV Patients Following Ablation in a Tertiary Teaching Hospital in Addis Ababa, Ethiopia.

BackgroundPosterior urethral valve (PUV) is the most common cause of congenital lower urinary tract obstruction in boys. It is considered that early diagnosis and intervention have good outcomes in terms of renal function, though the varying extent of embryological insult requires these boys to remain in extended follow-up and care.ObjectiveTo assess the renal outcome of patients following PUV ablation.MethodsThis was a descriptive retrospective study. Data were collected from the operation logbooks of patients from 2015 to 2019 that had been admitted to the Tikur Anbessa Specialized Hospital pediatric surgery unit with a working diagnosis of PUV and had ablation done primarily or following diversion. Data were collected from January to April 2020 and analyzed using SPSS 25. P value≤0.05 was considered significant.ResultsSeventy patients were analyzed and followed for 3 years for the development of postoperative chronic kidney disease (CKD) after PUV ablation. Postoperative CKD was found in 52.9% of patients and end-stage renal disease in 2.9%. Risk factors associated with postoperative CKD were the presence of preoperative and postoperative proteinuria, postoperative hypertension, and elevated nadir serum creatinine. Results also showed that a delay between the development of vesicostomy and ablation had a significant correlation with renal outcome. Elevated nadir serum creatinine, postoperative proteinuria, and delay between the development of vesicostomy and ablation were found to be independent risk factors of development of CKD.ConclusionThere was a high rate of CKD development in patients who had had ablation for PUV, which was comparable to other studies. Three variables were found to be independent risk factors for the progression of CKD, unlike other findings seen in low- and middle-income countries.

Does Delayed Presentation of Posterior Urethral Valve Carry Worse Prognosis?

Posterior urethral valve (PUV) is the most common cause of lower urinary tract obstruction in male neonates, with an incidence of 1 in 8000–25,000 live births. The clinical course of PUV diagnosed late in life is quite unpredictable. The prognosis of late-diagnosed PUV depends chiefly on the renal function at presentation. A literature search was performed on the delayed presentation of PUV. Serum creatinine at presentation, nadir serum creatinine (defined as the lowest creatinine attained in the year after valve ablation), and renal parenchymal echogenicity were significant predictors of final renal outcome. A generalization cannot be made regarding the prognosis of late-presenting PUV patients. The prognosis varies from case to case. If renal function at presentation and after valve ablation is preserved, then late-presenting PUVs carry good prognosis. Age per se does not carry any prognostic significance.

Posterior urethral valves and the risk of neurodevelopmental disorders in two FINNISH cohorts

The Posterior Urethral Valve (PUV) is a persistent membrane of the urethra, which causes obstruction in the urogenital tract in boys. To our knowledge, no comprehensive reports have been published on whether PUV is associated to neurodevelopmental disorders. Here, we analyzed a cohort of PUV patients for neurodevelopmental disorders and verified findings in an older cohort. In a register based study, we reviewed the hospital registries for patients treated for PUV during 1992-2013 to identify those with neurodevelopmental disorders. Primary outcome measure was any neurodevelopmental diagnosis. Secondary outcome measures were specific disorders: ASD; ADHD, intellectual disability, learning disabilities. Birth weight and gestational age were recorded, serum creatinine levels at specific timepoints were noted. We then investigated these variables to see any correlations to neurodevelopmental disorders. We replicated the strategy for verification in an older cohort of PUV-patients, who had been treated in our institute during 1970-1991. We identified 87 patients treated for PUV of which thirteen (15%) had a verified diagnosis of a neurodevelopmental disorder. 2.3% of PUV patients fulfilled criteria of mild intellectual disability (F70.0/F79.0), 9% had ADHD/ADD-spectrum diagnoses (F90.0/F90.9) and 2.3% had learning disabilities (F83/F81.3). 5.7% of patients presented with difficulties in social interactions (F93.89, F94.8). Five patients presented with more than one neurodevelopmental diagnosis. We confirmed these findings in the older cohort of patients, where a verified neurodevelopmental diagnosis was detected in 14% of patients. We identified no statistically significant associations to gestational age, birth weight or creatinine levels of PUV-patients with neurodevelopmental diagnoses as compared to the PUV-patients not diagnosed for neurodevelopmental disorders. Intellectual disability/mental retardation was more prevalent in our material and this association was statistically significant. We show, that the prevalence of intellectual disability among PUV patients exceeds the cumulative prevalence in Finland in both cohorts analyzed here. 15% of PUV-patients presented with a diagnosis of a neurodevelopmental disorder. To our knowledge, this is the first study attempting to outlineneurodevelopmental disorders among boys with PUV. This study has limitations. It is register based and only diagnoses made at an institute within our hospital district are considered. The PUV-patients may be under closer surveillance than age-matched healthy children, which may lead to an overrepresentation of cases. The patient number is small and the small subsets of patients within each cohort hamper any further statistical analysis. The neurodevelopmental impacts of pediatric general anesthesia remain elusive and may have corollaries which must be kept in mind when interpretating our results. Patients with PUV require close follow-up in a multi-disciplinary manner, not forgetting neurodevelopmental aspects. Attention to intellectual disability is mandatory. Any suspicion of a developmental delay in a patient with PUV warrants further investigation and corresponding interventions.

Association of Renal Glomerular and Tubular Function With Renal Outcome in Patients With Posterior Urethral Valves

ObjectiveTo analyze renal glomerular and tubular function and their association in patients operated for posterior urethral valves and to prognosticate the risk for end-stage kidney disease (ESKD) MethodsSixty-three previously treated patients were evaluated for renal function during 1987-1991. The patients’ age at evaluation was 11 years (range 2-24). Glomerular function was assessed by measuring glomerular filtration rate (GFR) and urine albumin excretion. Tubular function was determined by measuring urine concentration capacity and excretion of electrolytes (Na, K, Cl, Ca, P, Mg) and β-2-microglobulin. Additionally, the prevalence of hypertension and serum parathyroid hormone and aldosterone values were registered. Tubular function was compared with GFR and the risk of developing ESKD before November 2018. ResultsTwenty of the study patients (32%) had decreased GFR. In addition, 19% had proteinuria and 56% were hypertensive. Those without proteinuria or hypertension had better GFR values (P < .01 for both). There was a significant correlation between GFR and all the tubular function (P < .05) variables (except excretion of chloride) measured. Compared to the patients with favorable renal outcome, the patients (n = 10) who later developed ESKD had significantly (P < .01) lower GFR and reduced urinary excretion of all measured electrolytes except calcium. Consistently, urine β-2 microglobulin and serum parathyroid hormone and aldosterone values were significantly higher in the patients who developed ESKD (P ≤ .01). ConclusionBoth glomerular and tubular function decline was common and several parameters were likely to predict ESKD in posterior urethral valves patients.

Renal, Bladder and Sexual Outcomes in Adult Men with History of Posterior Urethral Valves Treated in Childhood

To determine the adulthood outcomes of bladder, kidney, and sexual functions of posterior urethral valve (PUV) patients. The records of patients who were treated for PUV between 1980, and 2001 and aged ≥18 years by the end of 2019 were retrospectively reviewed. Patients with complete adulthood data were included in the study. Renal, bladder, and sexual functions were assessed. Adulthood uroflowmetry results of 22 patients were also evaluated. Thirty-nine patients with complete adulthood data out of 89 were included. The median follow-up time was 22.7 years (15-33 years). Median age at initial surgery for PUV was 36 months (1-168 months), and median age at last follow-up was 26 years (18-46 years). Lower urinary tract dysfunction was noted in 15 (38%) patients. In 22 patients (56%) with uroflowmetric analyses, median values of Qmax, voided volume, and post voiding residual urine volume were 20.5 mL/sec (7-43 mL/sec), 389 mL (154-1750 mL), and 18.5 mL (range 0-190 mL), respectively. Nineteen patients (48.7%) had normal glomerular filtration rate, 2 patients (5.1%) had chronic kidney disease, and the remaining 18 patients (46.1%) had end stage renal disease, 14 (35.9%) of whom underwent renal transplantation. Thirty-two patients (82%) had sexual function evaluation, none of which reported erectile dysfunction. However, 4 patients (12.5%) reported slow ejaculation. Five patients fathered a child whereas infertility was observed in 2 patients. After 2 decades, glomerular filtration rate was normal almost in half of the PUV patients while lower urinary tract dysfunction was detected in 38%. Furthermore, erectile dysfunction was rare.

Urodynamics in Posterior Urethral Valve: Pursuit of prognostication or optimisation

Detrusor dysfunction is known to persist in several patients of Posterior Urethral Valve (PUV) after successful fulguration leading to progressive deterioration of renal function. Persistent bladder outlet obstruction (BOO) in the form of bladder neck hypertrophy, residual valves or strictures may contribute to progressive detrusor dysfunction. These are assessed radiologically or cystoscopically and are managed variedly by anticholinergics, alpha-adrenergic blockers or even bladder neck incision. Unfortunately, currently we do not have any objective measures to evaluate the degree of BOO in children or follow treatment outcome of any such measures. To assess the feasibility of pressure flow studies in children and proposition of an age independent index to quantify outflow parameters. We retrospectively studied the urodynamic data of the follow up cases of PUV who had been referred to us for urodynamic evaluation. Free flow uroflowmetries and filling and voiding cystometrogram were performed as per recommended protocol. Parameters like Adjusted Bladder Capacity (ABC = Voided volume+post void residue; expressed as percentage of expected bladder capacity {EBC}), overactivity, compliance, Qmax and P det at Qmax were taken into consideration. Indices like Bladder Outlet Obstruction Index (BOOI) and Bladder Contractility Index (BCI) were calculated. Multivariate analysis was run to assess correlation of ABC with other parameters. Receiver Operating Characteristics (ROC) curve analysis was performed to assess predictive values of BOOI for ABC. We did not find the ABC to change with age as has been classically described. Qmax and BCI were found to correlate with age. Values obtained for P det at Qmax and BOOI were not dependent on age and were in similar range as observed in adults. On multivariate analysis, small bladder was found to positively correlate with presence of overactivity, high BOOI and low BCI. ROC curve analysis showed a BOOI >29 could predict ABC to be <100% EBC with moderate sensitivity and specificity. Pressure flow studies are the only objective means of quantifying outlet resistance, hitherto they have been considered to be unrepresentative in children. Documentation and correction of high outflow pressures may arrest the cycle of detrusor hypertrophy and dysfunction. Quality pressure flow studies are feasible in children. Values of P det at Qmax and BOOI in children are age independent and similar to those observed in adults. BOOI can be potentially used in children to assess degree of BOO.

Urodynamic Changes with Age in Boys with Posterior Urethral Valves

Introduction: Bladder dysfunction is a common cause of morbidity in posterior urethral valve (PUV) patients and urodynamic study provides a useful tool to identify the bladder dysfunction. The aim of this study was to evaluate the urodynamic patterns in different age groups in PUV patients. Material and Methods: Toilet trained patients more than 4 years of age were included in the study. Invasive urodynamic study was done in all patients. Patients were divided in to the three groups; Group-1 (4-8 years), group-2 (9-13 years) and group-3 (14-18 years). Various urodynamic parameters which were noted in each patient include compliance, bladder stability, bladder capacity, detrusor pressure during voiding, detrusor sphincter dysynergia and post void residue. Results: 47 patients were included in the study. Age of patients ranged from 4 years to 17.8 years with mean age of 6.4 years. Bladder hyperreflexia (14.3% in group-1, 14.3% in group-2 and 8.3% in group-3), poor compliance (9.5% in group-1, 28.6% in group-2 and 41.7% in group-3), bladder capacity (normal in 76.2% group-1, 50.0% in group-2 and 33.3% in group-3), (decreased in 14.3% group-1, 28.6% in group-2 and 16.7% in group-3) and (increased in 9.5% group-1, 21.4% in group-2 and 50.0% in group-3), detrusor pressure during voiding (sustained in 42.5% group-1, 42.8% in group-2 and 25.0% in group-3), (waxing and waning in 28.6% group-1, 28.6% in group-2 and 41.7% in group-3) and myogenic failure in 14.3% group-1, 21.4% in group-2 and 33.3% in group-3. Conclusion: Urodynamic pattern shows considerable overlap during childhood and through adolescence with hyper contractility generally seen in young children and hypo contractility and myogenic failure in older boys.

Posterior Urethral Valves with Lower Urinary Tract Symptoms: Perspective on Urodynamics

Background Lower urinary tract symptoms (LUTs) are common in young boys with posterior urethral valves (PUVs). It is crucial to investigate the characteristics of PUV patients with and without LUTs after valve ablation. Methods Between January 2017 and December 2019, PUV patients visited Children’s Hospital, Fudan University for following up were enrolled. Medical records and information from the patients’ urodynamic studies (UDS) were reviewed. Results A total of 54 enrolled PUV patients were divided into symptomatic PUV group (28 cases) and non-symptomatic PUV group (26 cases) according to daytime incontinence or not, and 21 OAB cases without structural abnormalities were set as UDS control group. The non-symptomatic PUV patients had lager filling volume (135 ± 46% of EBC) than the symptomatic PUV patients and OAB patients (106.1 ± 44.4% of EBC, p = 0.0255 and 88.1 ± 39.6% of EBC, p = 0.0007, respectively). The detrusor pressure at 1/4 and 3/4 of full filling was higher in PUV groups than the control group, but no significant difference was found between the PUV groups. PUV patients with LUTs had a higher rate (19/28, 67.9%) of impaired bladder compliance than non-symptomatic PUV patients (11/26, 42.3%, p = 0.0489). The PUV patients with LUTs had a trend of worse kidney functions in lower GFR, higher serum creatinine and lower estimated GFR. Conclusion PUV patients have higher detrusor pressure regardless of the presence or absence of LUT symptoms. Bladder function assessments are needed in boys with PUV, even without incontinence symptoms after valve ablation.

Anterior urethral valves – A rare but challenging congenital pathology

Anterior urethral valves (AUV) and associated anterior urethral diverticula (AUD) are a rare cause of congenital lower urinary tract obstruction. They occur 25-30 times less frequently than posterior urethral valves (PUV) and historically tend to have a less aggressive presentation and outcome. However, due to the low incidence, little is known about management and long-term prognosis. We aim to evaluate the outcomes after AUV valve ablation and compare this group to a previously studied PUV cohort. In this IRB-approved study, we retrospectively identified all patients from 2002 to 2017 undergoing valve ablation using CPT code 52400. Charts were manually reviewed to identify AUV patients, their presenting symptoms, timing of diagnosis, pre and postnatal imaging findings, age at presentation and valve ablation, creatinine, recurrences, additional surgeries and follow-up. The AUV group was then compared to a previously studied PUV cohort of 104 patients from our institution. Nine AUV patients were identified. Only four (44%) patients were diagnosed prenatally. Three (33%) patients were diagnosed neonatally, one for weak stream/dribbling and two for febrile UTIs. The remaining two patients were diagnosed at ages 3 and 4 due to dysuria and penile swelling with micturition. Patients presenting later in life had no evidence of renal dysfunction or VUR. All patients underwent primary TUR-AUV (1 laser, 4 cold knife, 4 cautery), but 55% had residual valves and/or diverticula identified on routine postoperative imaging in two patients and due to development of clinic symptoms in three patients. All five patients with recurrences underwent repeat endoscopic evaluation, and thereafter two patients required urethral reconstruction. In contrast, only 15% (16/104) of PUV patients required re-TUR (p=0.01). At an average follow-up time of 4.24 years (range 0.6-11.4 years), 44% of patients had no evidence of CKD, and two patients (22%) had progressed to CKD of at least stage IIIA, compared to 21.4% in the PUV cohort at a mean follow-up of 2.3 years. The overall incidence of AUV is low, making it difficult to characterize these patients definitively. However, despite a milder phenotype and later presentation in most AUV patients, they do require more aggressive surgical treatment for complete resolution of the AUV. Furthermore, the long-term renal outcomes appear more severe than previously reported. The poorer outcomes of AUV patients both with respect to recurrence and long-term CKD indicate that close urologic follow-up is essential in this group.

Renal Tubular Functions in Patients with Posterior Urethral Valve

Objectives: The aim of this study was to evaluate tubular functions of posterior urethral valve patients with preserved glomerular functions. Methods: A total of 25 children (ages 1 - 18) who underwent surgery for PUV and had an estimated glomerular filtration rate ≥ 90 mL/min per 1.73 m2 on long term follow-up and age-matched 25 healthy controls were enrolled. Blood and urine samples were collected to assess electrolyte reabsorption, proteinuria, enzymuria, urine acidification and concentration. Results: Even though microalbumin/creatinine ratio was higher in the patient group [1.00 (1.98) vs 0.31 (0.34) mg/gr creatinine, P = 0.005] none of the subjects had enzymuria, overt proteinuria or hyperphosphaturia. Serum bicarbonate levels were lower and urinary pH higher in patients than the controls (23.2 ± 2.1 vs. 24.6 ± 1.9 mmol/L, P = 0.028 and 6.24 ± 0.77 vs. 5.60 ± 0.64, P = 0.004); furthermore, patients had lower urinary osmolality and density (525 ± 214 vs. 743 ± 194 mOsm/L, P = 0.001 and 1011 ± 5.0 vs. 1016 ± 6.8, P = 0.005). When patients were compared among themselves according to presence or absence of renal scarring and when patients without renal scars were compared to healthy controls, similar findings persisted. Conclusions: This study showed that during long-term follow-up of posterior urethral valve patients with normal glomerular filtration rates, even though proximal tubular functions do not seem to be impaired, acidification and concentration defects exist indicating distal tubulopathy.

Early use of Bladder Relaxant (Oxybutynin) in Posterior Urethral Valve Patients. Is it Justified

Introduction: Posterior Urethral Valves (PUV) constitute the most common infravesical urinary obstruction in boys. Bladder dysfunction, the pattern of which changes with the age and is common cause of morbidity in PUV patients. Urodynamic study provides a useful tool to identify the bladder dysfunction and allow timely and appropriate management. The aim of this study was to determine the efficacy of early use of bladder relaxant (oxybutynin) on urodynamic parameters in PUV patients and to compare our results with other authors. Material and Methods: Patients with posterior urethral valves more than 4 years of age were included in the study. After the diagnosis, oxybutynin was started prophylactically in all patients. Invasive urodynamic study was done in all patients minimum one year after start of oxybutynin. Bladder relaxant (oxybutynin) was stopped 48 hours before the study. Various urodynamic parameters which were noted in each patient include compliance, bladder stability (normal/overactivity), bladder capacity, detrusor pressure during voiding (sustained, waxing and waning or myogenic failure), detrusor sphincter dysynergia and post void residue. Results: 47 patients were included in the study. Age of patients ranged from 4 years to 14.8 years with mean age of 8.4 years. Normal detrusor pressure during filling (stable bladder) was seen in 95.7% of patients, bladder overactivity in 4.3% of patients, compliance (compliance good in 89.4% and compliance poor in 6.4%), bladder capacity (normal (70.2%), decreased (10.6%) and increased (19.1%), detrusor pressure during voiding (sustained (68.1%), waxing and waning (21.3%) and myogenic failure (10.6%)). Conclusion: Early use of oxybutynin immediately after the diagnosis of PUV, improves the urodynamic parameters in these patients possibly because of protective effect of oxybutynin on bladder function and structure.

A clinical predictive model of chronic kidney disease in children with posterior urethral valves.

Posterior urethral valves (PUVs) are associated with severe consequences to the urinary tract and are a common cause of chronic kidney disease (CKD). The aim of this study was to develop clinical predictive model of CKD in a cohort of patients with PUVs. In this retrospective cohort study, 173 patients with PUVs were systematically followed up at a single tertiary unit. The primary endpoint was CKD ≥ stage 3. Survival analyses were performed by Cox regression proportional hazard models with time-fixed and time-dependent covariables. Mean follow-up time was 83months (SD, 70months). Sixty-five children (37.6%) developed CKD stage ≥ 3. After adjustment by the time-dependent Cox model, baseline creatinine, nadir creatinine, hypertension, and proteinuria remained as predictors of the endpoint. After adjustment by time-fixed model, three variables were predictors of CKD ≥ stage 3: baseline creatinine, nadir creatinine, and proteinuria. The prognostic risk score was divided into three categories: low-risk (69 children, 39.9%), medium-risk (45, 26%), and high-risk (59, 34.1%). The probability of CKD ≥ stage 3 at 10years age was estimated as 6%, 40%, and 70% for patients assigned to the low-risk, medium-risk, and high-risk groups, respectively (P < 0.001). The main limitation was the preclusion of some relevant variables, especially bladder dysfunction, that might contribute to a more accurate prediction of renal outcome. The model accurately predicts the risk of CKD in PUVs patients. This model could be clinically useful in applying timely intervention and in preventing the impairment of renal function.