Posterior urethral valve in thai boys.

BACKGROUND: Posterior urethral valve (PUV) is the most common congenital bladder outlet obstruction in boys, causing renal damage beginning in utero. There are scarce data from Thailand regarding the long-term outcomes of PUV in boys, thus the aim of this study was to examine the presentation, clinical course, complications, outcomes and renal survival in PUV boys. METHODS: We reviewed the medical records of PUV boys treated at the Pediatric Nephrology Clinic, Prince of Songkla University, Thailand, over a 30-year-period. RESULTS: Seventy-seven PUV boys were identified, with a median age at diagnosis of 4.8 months. The most common presentations were urinary tract infection (UTI), poor urine stream and urinary dribbling in 26 (33.8%), 19 (24.7%) and 11 (14.3%) boys, respectively. Renal ultrasound results in 70 boys showed 8 (11.4%) unilateral and 56 (80%) bilateral hydronephroses. Of 72 voiding cystourethrograms, 18 (25.0%) showed unilateral and 22 (30.6%) bilateral vesicoureteral refluxes. 99mTc dimercaptosuccinic acid renal scans in 30 boys showed 12 (40%) unilateral and 8 (26.7%) bilateral renal damage. Fifty-nine (76.6%) boys had 149 UTIs; 42 (54.4%) had recurrent UTI. Forty-eight boys had valve ablation at the median age of 30.3 months. 22 boys (28.6%) developed chronic kidney disease (CKD) at a median age of 15.0 years. CONCLUSION: Of 77 PUV Thai boys, UTI was the most common presentation. Recurrence of UTI and CKD was the most common consequence. Lifelong follow-up for renal and bladder functions is essential for all PUV patients.

Rare Variants in BNC2 Are Implicated in Autosomal-Dominant Congenital Lower Urinary-Tract Obstruction.

Congenital lower urinary-tract obstruction (LUTO) is caused by anatomical blockage of the bladder outflow tract or by functional impairment of urinary voiding. About three out of 10,000 pregnancies are affected. Although several monogenic causes of functional obstruction have been defined, it is unknown whether congenital LUTO caused by anatomical blockage has a monogenic cause. Exome sequencing in a family with four affected individuals with anatomical blockage of the urethra identified a rare nonsense variant (c.2557C>T [p.Arg853∗]) in BNC2, encoding basonuclin 2, tracking with LUTO over three generations. Re-sequencing BNC2 in 697 individuals with LUTO revealed three further independent missense variants in three unrelated families. In human and mouse embryogenesis, basonuclin 2 was detected in lower urinary-tract rudiments. In zebrafish embryos, bnc2 was expressed in the pronephric duct and cloaca, analogs of the mammalian lower urinary tract. Experimental knockdown of Bnc2 in zebrafish caused pronephric-outlet obstruction and cloacal dilatation, phenocopying human congenital LUTO. Collectively, these results support the conclusion that variants in BNC2 are strongly implicated in LUTO etiology as a result of anatomical blockage.

Biometric and morphological features on magnetic resonance imaging of fetal bladder in lower urinary tract obstruction: new perspectives for fetal cystoscopy.

OBJECTIVES: Incompatibility between currently available fetoscopes and the anatomical constraints of the distended fetal bladder, with the resulting curvature around the bladder neck, account for most technical difficulties during fetal cystoscopy in lower urinary tract obstruction (LUTO). The aim of this anatomical study was to assess by magnetic resonance imaging (MRI) the variation in three bladder angles (bladder-neck angle (BNA), vesicourethral angle (VUA) and angle between bladder dome and posterior urethra (DUA)), according to gestational age (GA), bladder volume and the presence of LUTO. METHODS: From our fetal medicine database, we retrieved for review 46 MRI examinations of male fetuses between 2015 and 2019, including 17 with LUTO, examined at a mean GA of 28.1 (range, 17.3-35.0) weeks and 29 age-matched controls, examined at 29.9 (range, 21.9-35.0) weeks. We measured bladder volume, bladder-wall thickness and the three bladder angles, and used the Mann-Whitney U-test to compare values between groups. Variations according to GA and bladder volume were determined using analysis of variance (ANOVA). A reliability study was performed using the Bland-Altman method and Lin's correlation coefficient was calculated. RESULTS: Both bladder volume and bladder-wall thickness were significantly greater in the LUTO group (P < 0.01). BNA was significantly larger in LUTO compared with control fetuses: the mean (range) was 127.1° (101.6-161.6°) vs 111.2° (88.5-157.3°) (P < 0.01). DUA averaged 117° and showed no difference between the groups (P = 0.92). No statistical comparison was performed on VUA since this was not measurable in most control fetuses. ANOVA showed no variation of any angle with bladder volume in both LUTO fetuses and control fetuses. BNA in LUTO fetuses was the only angle to vary with GA, being larger after, compared with at or before, 25 weeks (P = 0.04). The reliability study showed an acceptable bias for both intra- and interobserver reproducibility for all three angles. CONCLUSION: The findings that BNA is increased by approximately 15° in fetuses with LUTO and DUA averages 117° could aid in development of a customized fetal cystoscope and help to overcome the current technical challenges of fetal cystoscopy. Copyright © 2019 ISUOG. Published by John Wiley & Sons Ltd.

Current State of Fetal Intervention for Lower Urinary Tract Obstruction.

PURPOSE OF THE REVIEW: In this article, we explore the origins of intervention of fetal lower urinary tract obstruction, and we specifically discuss the background and recent outcomes of vesicoamniotic shunt placement and fetal cystoscopy. The article seeks to provide a comprehensive overview of the field while bringing the reader quickly up to speed on the pertinent literature and the critical data that are available to guide decision-making regarding intervention. RECENT FINDINGS: Appropriate patient selection for fetal intervention remains challenging despite advances in prenatal imaging. Both a randomized controlled trial and multiple systematic reviews show evidence of a perinatal survival benefit following fetal intervention but rates of renal morbidity remain very high. Despite 30 years of research, fetal lower urinary tract obstruction remains a difficulty entity to treat. Intervention may lead to survival, but physicians and caregivers must remain alert for the distinct possibility of long-term renal morbidity in survivors.

Long-term renal outcome in infants with congenital lower urinary tract obstruction.

INTRODUCTION: Congenital Lower Urinary Tract Obstructions (LUTO) is a heterogeneous group of diseases in which urine elimination is obstructed at the level of bladder neck or urethra. The aim of the study is to evaluate the long-term renal outcome of patients suffering of congenital LUTO. PATIENTS AND METHOD: We retrospectively reviewed patients with congenital LUTO. All patients had at least 1 year follow-up. Data on surgery, renal imaging and Schwartz estimate creatinine clearance were collected. Incidence of Chronic Renal Disease (CRD) is presented with Kaplan-Meier method. RESULTS: 40 patients were included, 23 patients with Posterior Urethral Valve (PUVs) and 17 patients with other aetiologies: anterior urethral valve (2), urethral atresia (2), urethral stenosis (2), cloacal malformations (2), obstructive ureterocele (1), bladder trigone malformation (1) and neonatal bladder-sphincter dysfunction without neurological abnormalities (7). Incidence of CRD at age 10 years was 37% in congenital LUTO, 42% in PUVs and 30% in other aetiologies, and was significantly higher in PUVs (P=0.032). Renal prognosis was significantly worsened by discover of retentional bladder wall changes in initial cystoscopy, and by loss of parenchymal differentiation or cortical microcysts in first ultrasonography. The use of urinary diversion was significantly higher in LUTO of other aetiologies. CONCLUSION: A high incidence of CRD is observed in patients with congenital LUTO, significantly higher in patients with PUV. LUTO of other aetiologies require step by step surgical management and higher use of urinary diversion. Precise initial evaluation in cystoscopy and ultrasonography is required and participate to evaluate future renal outcome. LEVEL OF INCIDENCE: 4.

[Lower urinary tract obstruction (LUTO)--clinical picture, prenatal diagnostics and therapeutic options]. / Lower Urinary Tract Obstruction (LUTO)--Krankheitsbild, pränatale Diagnostik und Therapiemöglichkeiten.

The aetiology of urinary tract obstructions (LUTO) is heterogeneous. The most common entities are isolated posterior urethral valves or urethral atresia in male foetuses. In female foetuses LUTO is frequently a part of complex malformations. The natural history of LUTO is characterised by high morbidity and mortality due to the development of severe pulmonary hypoplasia caused by oligo- or anhydramnios affecting the cannalicular phase (16-24 weeks of gestation) of pulmonary development. The degree of renal damage is variable and ranges from mild renal impairment in infancy to end-stage renal insufficiency, necessitating dialysis and transplantation. Foetal interventions in order to bypass the obstruction are biologically plausible and technically feasible. Vesico-amniotic shunting as well as (currently less frequent) foetoscopic cystoscopy and laser ablation of posterior urethral valves are minimally invasive treatment options. Previous reports indicate that prenatal therapy is suitable to reduce perinatal mortality but does not improve postnatal renal function. Selection of foetuses who may profit from prenatal intervention is aggravated by the lack of reliable prognostic criteria for the prediction of postnatal renal function in both ultrasound and foetal urine analysis. Furthermore, there is no randomised trial available at the time of writing. Because of a relevant complication rate and still no clear evidence for foetal benefit, interventions should be performed in specialised centres. Further studies are necessary to improve case selection of affected foetuses and to evaluate the impact of interventions in earlier gestational weeks. The data from the PLUTO trial (percutaneous shunting in lower urinary tract obstruction) conducted by the University of Birmingham may help to answer these questions. In the meantime selection of foetuses for prenatal intervention puts high requirements on interdisciplinary counselling in every case. A general treatment algorithm for foetal therapy is not available at the moment.

Development of an animal model to study congenital urinary obstruction.

PURPOSE: We outline the development of a reliable model of obstructive uropathy in fetal lambs highlighting our understanding of the critical time points for interventions and the variability of any such model. We identify some discoveries that may have clinical implications. METHODS: The model requires 60-day-gestation fetal lambs. In lambs, glomerulogenesis is complete by 90 days gestation. (Term is 145 days.) The ability to develop a reliable method of creating bladder outlet obstruction in females, ligating both the urethra and urachus was critical. The lambs are bred to an accuracy of ±24 h. RESULTS: Creating the model at 50-60 days gestation, produces different expressions of renal dysplasia in groups of lambs undergoing identical interventions at the same stage of gestation. Early complete urethral obstruction can produce the Potter phenotype. An appropriately timed vesico-amniotic shunt preserves renal development, producing a shrunken, non-compliant bladder. Shunting the normal fetal bladder at 80 days gestation produces a similar bladder. Provision of a low-pressure valve in the shunt preserves bladder development and compliance. Using a high-pressure shunt produces results similar to non-shunted lambs. DISCUSSION: We developed a reliable animal model for obstructive uropathy. Being alert to peripheral results can lead to new findings.

Congenital lower urinary tract obstruction: a population-based epidemiological study.

OBJECTIVE: To determine the prevalence and outcome of lower urinary tract obstruction (LUTO), including the sensitivity of antenatal diagnosis. DESIGN: A retrospective population-based study. SETTING: Regional population-based congenital anomalies register (WMCAR). POPULATION: Fetuses affected by LUTO delivered between 1995 and 2007 to women resident in the West Midlands. METHODS: Cases were selected from the WMCAR using codes and keyword terms from the International Classification of Diseases, tenth revision (ICD10). Diagnoses were validated using additional data sets from Regional Fetal Medicine, Perinatal Pathology and Paediatric services. MAIN OUTCOME MEASURES: Rates of prevalence, prenatal diagnosis and mortality, with trends. RESULTS: There were 284 LUTO cases in 851 419 births during the study period, representing a total prevalence of 3.34 (2.95-3.72) per 10 000 births, and this prevalence did not change significantly over time. The prevalence of LUTO was significantly higher in Black and minority ethnic groups when compared with white Europeans (OR 2.38; 95% CI 1.87-3.03), and are associated with area-based deprivation measures (P < 0.01). Of all LUTO cases, 221 (77.8%) were isolated, and the remainder were associated with other structural or chromosomal anomalies. The most common subtype was posterior urethral valves (PUVs; n = 179, 63%). In total there were 211 (74.3%) cases of isolated, non-female, singleton fetuses that fitted the referral criteria for in utero vesico-amniotic shunting, giving a prevalence of 2.48 (2.14-2.81) per 10 000 live births. Within this group, the prenatal diagnosis rate was 46.9% (99/211). CONCLUSION: This is the largest population-based study of LUTO that has been performed to date, and provides accurate estimates for prevalence. The low prevalence and relatively low rate of antenatal detection limit the number of cases amenable to prenatal surgical intervention.

Posterior urethral valves: long-term outcome.

Posterior urethral valves represent the most common cause of bladder outlet obstruction in infancy that impairs renal and bladder function. Long-term outcome of patients with previous PUV is evaluated. Patients over 18 years of age, treated from 1982 to 1995 before the age of 3 years were considered. Previous surgery, renal function, bladder activity, urinary incontinence, and fertility/sexual activity were evaluated. Clinical interview, creatinine clearance, uroflowmetry with ultrasound post-void urine residue, and self-administered questionnaire were recorded. Out of 45 identified records, 24 patients (53.3%) accepted to be enrolled (age 18-34 years, mean 23 years). The mean follow-up was 19.5 years (16-30 years). Out of the 21 excluded patients, 20 did not reply to the clinical interview and 1 died at age of 6 years. All the 24 patients had early endoscopic section of PUV; nine also received transient ureterocutaneostomy or vesicostomy. Ureteroneocystostomy was performed in five patients and ureterocystoplasty with unilateral nephrectomy in two. At follow-up chronic renal failure was detected in 13 patients (54.1%) and 9 (37.5%) had arterial hypertension. End-stage renal disease developed in five patients (20.8%): three had successful renal transplantation and two were in dialysis. Lower urinary tract symptoms were present in seven patients (29.1%). No significant fertility deficit and sexual dysfunction were observed in 23 patients, while 1 patient was azoospermic. No paternity was reported so far. Long-term outcome of patients with previously treated PUV is mandatory. Kidney, bladder, and sexual functions should be monitored till adulthood to verify any modified behaviour.

An atypical bladder diverticulum presented with recurrent peritonitis: case report.

Bladder diverticula develop from congenital detrusor muscle defect and frequently present with urinary tract infection, which occurs as a result of urinary stasis in the diverticula. Different clinical presentations, such as bladder outlet obstruction, cyanosis of the lower extremities, intestinal obstruction, ureteral obstruction (which may occur due to direct diverticular compression), and peritonitis due to spontaneous rupture of the diverticula, were reported previously. Here, we report a case with the diagnosis of bladder diverticulum that caused recurrent generalized peritonitis without perforation and mimicked perforated appendicitis.

Phenotypic transition of the collecting duct epithelium in congenital urinary tract obstruction.

Epithelial-mesenchymal transition (EMT) has emerged in recent years as an important process in the development of organ fibrosis in many human diseases. Our previous experience in a nonhuman primate model of obstructive nephropathy suggested that EMT of collecting duct epithelium contributes to the development of interstitial fibrosis. In this study we demonstrate for the first time in humans that obstructed fetal collecting duct epithelium undergoes transition to mesenchymal phenotype, characterized by decreased expression of epithelial markers, de novo expression of mesenchymal markers with subsequent loss of cell-cell interaction, disruption of the basement membrane, and increased deposition of extracellular matrix into the expanded interstitium of the obstructed kidney. The results of this study therefore support the previous findings from animal studies and suggest that EMT of the collecting duct epithelium might contribute to the development of interstitial fibrosis in human fetal obstructive nephropathy.

Systematic review of the effectiveness of antenatal intervention for the treatment of congenital lower urinary tract obstruction.

BACKGROUND: Congenital lower urinary tract obstruction is associated with high mortality and morbidity. Antenatal detection has improved with advances in ultrasound technology, and has allowed the option of antenatal intervention. OBJECTIVES: To systematically review the literature to evaluate the effectiveness of antenatal interventions to improve perinatal survival and postnatal renal function in congenital lower urinary tract obstruction. SEARCH STRATEGY: Extensive electronic searches (database inception 2009) using Medical Subject Headings (MeSH) and keywords, without restrictions. Reference lists of included studies were checked, and all authors were contacted. SELECTION CRITERIA: Studies were selected according to a predefined protocol. The included studies were observational or randomised trials, where an intervention was performed in utero to treat congenital lower urinary tract obstruction, compared with another intervention or no treatment. DATA COLLECTION AND ANALYSIS: Data were extracted on study design, quality and results to construct 2 x 2 tables. Meta-analysis was performed where possible. Peto ORs with 95% CIs were computed. MAIN RESULTS: Prenatal bladder drainage improved perinatal survival compared with no treatment (OR 3.86, 95% CI 2.00-7.45). This effect was amplified in a subgroup with poor predicted prognosis (OR 12.85, 95% CI 1.25-153.03). However, although treatment increases survival, it appears that the residual risk of poor long-term postnatal renal function is uncertain (OR 0.50, 95% CI 0.13-1.90). AUTHOR'S CONCLUSIONS: Antenatal bladder drainage appears to improve perinatal survival in cases of congenital lower urinary tract obstruction, but may confer a high residual risk of poor postnatal renal function, based on observational studies. Randomised research with long-term follow up is necessary to determine the role of antenatal treatment in clinical practice.

Antenatal ultrasound to predict postnatal renal function in congenital lower urinary tract obstruction: systematic review of test accuracy.

BACKGROUND: Congenital urinary tract obstruction can lead to perinatal mortality and morbidity. Assessing antenatal ultrasound features may help identify fetuses likely to suffer complications. OBJECTIVE: To evaluate the accuracy of antenatal ultrasound in the prediction of postnatal renal function in cases of congenital lower urinary tract obstruction (LUTO). SEARCH STRATEGY: We conducted electronic searches in MEDLINE, EMBASE, the Cochrane Library, MEDION, SIGLE, SCISEARCH Index of scientific and technical proceedings, National Research Register (database inception - 2008) and Medical Conferences register and searched reference lists. SELECTION CRITERIA: Two reviewers independently selected articles in which the accuracy of fetal ultrasound features were evaluated to predict postnatal renal function with no language restrictions. DATA COLLECTION AND ANALYSIS: Data were extracted on study characteristics, quality and results to construct 2 x 2 tables. Likelihood ratios for positive (LR+) and negative (LR-) test results, sensitivity and specificity were generated for the different ultrasound parameters and reference standards. MAIN RESULTS: Thirteen articles that met the selection criteria, including 215 women and 33 2 x 2 tables. Meta-analysis was performed using clinically similar subgroups to minimise clinical heterogeneity. The ultrasound parameter that showed the best predictive value for postnatal renal function in survivors was renal cortical appearance, sensitivity 0.57 (95% CI 0.37-0.76) and specificity 0.84 (95% CI 0.71-0.94), area under the curve 0.78. CONCLUSION: Measurement of amniotic fluid volume and the appearance of the renal cortex at diagnosis of LUTO show promising predictive accuracy for poor postnatal renal function.

Rectal duplication cyst causing acute urinary retention with bladder outlet obstruction: an unusual presentation.

Anterior rectal duplication cyst is rare entity with <50 reported cases to date. It has myriad presentations like bleeding per rectum, constipation, rectal prolapsed and intestinal obstruction due to extrinsic compression of rectum. However, the association of enlarged duplication cyst compressing the bladder neck or ureter, and leading to bladder outlet obstruction or hydroureteronephrosis is extremely rare with only a handful of reported cases. We report a rare case of large anterior rectal duplication cyst in a young girl leading to acute urinary retention with bladder outlet obstruction which was eventually managed by laparoscopic-assisted transabdominal surgical excision of the cyst. The authors believe that such an association has not been previously reported in this age group.

Congenital urinary tract obstruction.

Congenital bladder neck obstruction (or lower urinary tract obstruction [LUTO]) describes a heterogeneous group of congenital anomalies presenting with similar prenatal ultrasonographic findings of dilated posterior urethra, megacystis, hydronephrosis, oligohydramnios and often with associated renal dysplasia. Untreated LUTO has high rate of perinatal morbidity and mortality from associated pulmonary hypoplasia and early-onset renal failure in infancy. Ultrasonographic features and prospective fetal urinalysis may help in predicting the overall prognosis of congenital LUTO. Currently, fetal vesicoamniotic shunt (of various designs), and fetal cystoscopy and fulguration of the obstruction are potential prenatal interventions. Retrospective and prospective cohort studies and a relatively small randomized controlled trial have demonstrated these treatments may possibly improve perinatal survival. Despite this, concerns remain as to the high rates of renal impairment observed in paediatric survivors. A clinical prospective scoring/staging system may improve prenatal diagnostic criteria and case selection for fetal therapy.

The role of renal biomarkers to predict the need of surgery in congenital urinary tract obstruction in infants.

INTRODUCTION: The diagnosis of renal function impairment and deterioration in congenital urinary tract obstruction (UTO) continues to be extremely challenging. The use of new renal biomarkers in this setting may favor early renal injury detection, allowing for a reliable choice of optimal therapeutic options and the prevention or minimization of definitive renal damage. OBJECTIVE: The aim of the study was to investigate a selection of promising biomarkers of renal injury with the intention of evaluating and comparing their profile with clinically based decisions for surgical intervention of infants with congenital obstructive uropathies. STUDY DESIGN: The first-year profile of renal biomarkers, serum creatinine (sCr), serum and urine cystatin C (CyC), neutrophil gelatinase-associated lipocalin (NGAL), kidney injury molecule-1 (KIM-1), transforming growth factor beta-1 (TGF-ß1), retinol-binding protein (RBP), and microalbuminuria (µALB), was analyzed in a cohort of 37 infants with congenital UTO, divided into three subgroups, 14 cases with grade III unilateral hydro(uretero)nephrosis, 13 cases with grade III bilateral hydro(uretero)nephrosis, and 10 cases with low urinary tract obstruction (LUTO), compared with 24 healthy infants matched by gestational age and birth weight. Serum and urine samples were stored at -70 °C and thereafter analyzed by quantitative enzymatic immunoassay. RESULTS: Compared with the control group (Figure), all renal biomarker values were significantly increased in patients (P ≤ 0.02). In the unilateral hydronephrosis and LUTO group, RBP (P ≤ 0.043), NGAL (P ≤ 0.043), KIM-1 (P ≤ 0.03), and TGF-ß1 (P ≤ 0.034) values dropped significantly after surgery. Neutrophil gelatinase-associated lipocalin alone and in combination with urine and serum CyC demonstrated the best performance in determining the need for surgery (area under the curve, 0.801 and 0.881, respectively). Biomarker profile analysis was suggestive of surgical intervention in 55.4% (7/13) of non-operated cases, and most of the biomarker values were above the cutoff levels within at least 3 months before the clinically based surgical decision in 58% (14/24) of all operated patients. DISCUSSION: To the best of the authors' knowledge, this is the first study to present the clinical use of selected group of serum and urinary biomarkers in the setting of UTO to distinguish between patients who would benefit from surgery intervention. The most promising results were obtained using NGAL, RBP, TGF-ß1, and KIM-1, especially in the unilateral hydro(uretero)nephrosis and LUTO subgroups when compared with the control group. CONCLUSIONS: Urine biomarkers, alone and in combination, demonstrated high potential as a non-invasive diagnostic tool for identifying infants who may benefit from earlier surgical intervention.

The postnatal management of boys in a national cohort of bladder outlet obstruction.

AIM: The most common cause of congenital bladder outlet obstruction (BOO) is posterior urethral valves (PUV). Initial treatment requires decompression, but transurethral incision (TUI) or primary diversion is all described. There is no randomized control trial to guide management. This study aims to describe management, circumcision, and UTI rate in a national cohort of PUV boys. METHODS: Boys diagnosed with BOO were recruited (via BAPS CASS) over 1 year with ethics committee approval (ref: 12/SC/0416). Data were collected via questionnaire, presented as number (%), analyzed by Mann-Whitney/chi-square/Fisher Exact tests, and p < 0.05 was taken as significant. RESULTS: BOO presented in 121 boys during 2014-2015, and 113 were PUV. Catheter placement in 87/121(72%) was more likely to happen in antenatal vs. postnatal vs. late(>1 y) presentations, p < 0.0001. Polyuria occurred in 23/45(51%), 12/48(25%), 0/28(0%), respectively, p < 0.0001. Initial surgical treatment was TUI in 108/121(89%) and vesicostomy in 2. Two ureterostomies were secondary procedures. Circumcision was performed in 52/121(43%) in antenatal presentation vs. postnatal vs. late 27/45(60%), 20/48(42%), 2/28(7%), respectively, p = 0.01. 69 UTIs occurred in 49 patients. Circumcision was associated with an 86% reduced risk of UTI, p < 0.0001. There was a 66% reduction in UTI risk associated with TUI alone, p < 0.01. There was 1 death due to pulmonary hypoplasia and renal failure, and 2 experienced end-stage renal failure (ESRF). CONCLUSION: Standard treatment for BOO and PUV in the current UK cohort is urethral catheterization followed by TUI. Supravesical diversion is a rescue therapy. UTIs are common and reduced by circumcision, with 43% being circumcised. Initial mortality rate was 1%, and 1.6% present in ESRF. LEVEL OF EVIDENCE: Prognostic study - Level I - Prospective National Cohort Study.

Current epidemiology and antenatal presentation of posterior urethral valves: Outcome of BAPS CASS National Audit.

AIM: Posterior urethral valves (PUVs) are the most common cause of congenital bladder outlet obstruction (BOO) in boys and end-stage renal failure (ESRF) in childhood. In the 1980s, 1 in 4000 boys had PUV. Presentation was 1/3 antenatal/neonatally, 1/3 postnatal, 1/3 late (>1 year). This study aimed to describe the current proportions in a contemporary cohort. METHODS: A national audit (BAPS CASS) of referrals in the UK and Ireland of boys diagnosed with suspected or confirmed PUV in a year was conducted. National registration data provided the male birth-rate. Data were presented as number (%), analysed by Mann-Whitney U-test and Chi-square test, with P < 0.05 taken as significant. The study was approved by a national ethics committee (NRES Committee South Central Oxford A (12/SC/0416)). RESULTS: Data were collected from 1st October 2014 to 30th September 2015 from 25/26 centres on 121 cases of suspected bladder outlet obstruction (BOO), of which 113 (93%) were because of PUV. The male birth rate during the period was 432,806/year. The calculated incidence of BOO was 1/3580 and for PUV was 1/3800 per-annum. The proportion of PUV presenting according to age was: antenatally (n = 40, 35%), infancy (n = 47, 42%), and late (n = 26, 23%). Plasma creatinine was higher in antenatally-diagnosed BOO vs. postnatal, 54 (39.5-109.5) µmol/l vs. 34(21-47) µmol/l, P = 0.0005. Hydronephrosis and ureteric dilatation were significantly greater in antenatally diagnosed BOO vs. postnatal vs. late. Renal dysplasia (cortical thinning, poor corticomedullary differentiation, or renal cysts) was significantly more likely in antenatally diagnosed BOO. CONCLUSION: Neither the incidence (~1/4000) nor the proportion antenatally diagnosed (~1/3) of boys with PUV appears to have changed in the past 30 years. Those boys who were antenatally diagnosed have significantly higher postnatal plasma creatinine, more hydroureteronephrosis, and renal dysplasia than those diagnosed in infancy or later. It may be hypothesized that this is the reason they are detected antenatally. LEVEL OF EVIDENCE: Prognosis study - Level I - prospective national cohort study.