Posterior urethral valve

Primary non-refluxing megaureter: Natural history, follow-up and treatment

Primary non-refluxing megaureter (PMU) is a congenital dilation of the ureter which is not related to vesicoureteral reflux, duplicated collecting systems, ureterocele, ectopic ureter, or posterior urethral valves and accounts for 5 to 10% of all prenatal hydronephrosis (HN) cases. The etiology is a dysfunction or stenosis of the distal ureter. Most often PMU remains asymptomatic with spontaneous resolution allowing for non-operative management. Nevertheless, in selective cases such as the development of febrile urinary tract infections, worsening of the ureteral dilatation, or reduction in relative renal function, surgery should be considered.

CONCLUSION

Ureteral replantation with excision of the dysfunctional ureteral segment and often ureteral tapering is the gold-standard procedure for PMU, although endoscopic treatment has been shown to have a fair success rate in many studies. In this review, we discuss the natural history, follow-up, and treatment of PMU.

WHAT IS KNOWN

• PMU is the result of an atonic or stenotic segment of the distal ureter, resulting in congenital dilation of the ureter, and is frequently diagnosed on routine antenatal ultrasound.

WHAT IS NEW

• Most often, PMU remains asymptomatic and clinically stable, allowing for non-operative management. • Nevertheless, since symptoms can appear even after years of observation, long-term ultrasound follow-up is recommended, even up to young adulthood, if hydroureteronephrosis persists. • Ureteral replantation is the gold standard in case surgery is needed. In selected cases, however, HPBD could be a reasonable alternative.

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.

Mechanical Ablation of the Posterior Urethral Valve Omitting Thermal Energy: A Brief Report

Management of the posterior urethral valve (PUV) is a clinical challenge in pediatric urology. We report the results of a modified valve ablation method without using a pediatric resectoscope and thermal energy. Patients were selected from children with PUV who were referred to the pediatric urology clinic of Shahid Labbafinejad Hospital, Tehran, Iran, and have undergone endoscopic valve ablation surgery between May 2019 to May 2021. Ten male patients with PUV underwent mechanical valve ablation without the use of the conventional pediatric resectoscope, and thermal energy was replaced by a 6F semi-rigid urethroscope and 3Fr ureteral catheter. Patients were assessed both pre-and postoperatively using serum creatinine, urinary tract ultrasound imaging, and voiding cystourethrography. The mean age was 23.88±30.13 months (range= 25 days to 8 years). Four out of 10 patients (40%) had elevated serum creatinine, and seven had unilateral or bilateral hydroureteronephrosis (70%). No major complications were reported according to Clavien-Dindo Classification System. The level of serum creatinine, the grade of hydroureteronephrosis, and the ratio of the prostatic urethra to anterior urethra diameter in postoperative voiding cystourethrography were decreased. A decrease in serum creatinine level occurred in patients after valve ablation, but this decrease was not statistically significant (P=0.059). The decrease in hydroureteronephrosis grade on the right (P=0.006) and left (P=0.022) was statistically significant. There was no evidence of urethral stenosis or need for repeating resection. It can be concluded that our mechanical valve ablation method might be a safe and effective technique for PUV ablation.

Primary ablation versus urinary diversion in posterior urethral valve: Systematic review and meta-analysis

PURPOSE

To determine differences in long-term kidney and bladder outcomes in boys with posterior urethral valves (PUV) managed by a primary valve ablation or primary urinary diversion.

MATERIALS AND METHODS

A systematic search was performed in March 2021. Comparative studies were evaluated according to Cochrane collaboration recommendations. Assessed measures included kidney outcomes (chronic kidney disease, end-stage renal disease, kidney function) and bladder outcomes. Odds ratios (OR) and mean difference (MD) with 95% confidence interval (CI) were extrapolated from available data for quantitative synthesis. Random-effects meta-analysis and meta-regression were performed according to study design, and potential covariates were assessed with subgroup analysis. The systematic review was prospectively registered on PROSPERO (CRD42021243967).

RESULTS

Thirty unique studies describing 1547 boys with PUV were included in this synthesis. Overall effect estimates demonstrate that patients undergoing primary diversion have significantly increased odds of developing renal insufficiency [OR 0.60, 95% CI 0.44, 0.80; p < 0.001]. However, when adjusting for baseline kidney function between intervention groups, there was no significant difference in long term kidney outcomes [p = 0.09, 0.35], or the development of bladder dysfunction or requiring clean-intermittent catheterization with primary ablation rather than diversion [OR 0.89, 95% CI 0.49, 1.59; p = 0.68].

CONCLUSIONS

Current low-quality evidence suggests that medium-term kidney outcomes in children are similar between primary ablation and primary diversion after adjusting for baseline kidney function, while bladder outcomes are highly heterogenous. Further research with covariate control is warranted to investigate sources of heterogeneity.

LEVEL OF EVIDENCE

Level III.

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.

Modelling human lower urinary tract malformations in zebrafish

Advances in molecular biology are improving our understanding of the genetic causes underlying human congenital lower urinary tract (i.e., bladder and urethral) malformations. This has recently led to the identification of the first disease-causing variants in the gene BNC2 for isolated lower urinary tract anatomical obstruction (LUTO), and of WNT3 and SLC20A1 as genes implicated in the pathogenesis of the group of conditions called bladder-exstrophy-epispadias complex (BEEC). Implicating candidate genes from human genetic data requires evidence of their influence on lower urinary tract development and evidence of the found genetic variants' pathogenicity. The zebrafish (Danio rerio) has many advantages for use as a vertebrate model organism for the lower urinary tract. Rapid reproduction with numerous offspring, comparable anatomical kidney and lower urinary tract homology, and easy genetic manipulability by Morpholino®-based knockdown or CRISPR/Cas editing are among its advantages. In addition, established marker staining for well-known molecules involved in urinary tract development using whole-mount in situ hybridization (WISH) and the usage of transgenic lines expressing fluorescent protein under a tissue-specific promoter allow easy visualization of phenotypic abnormalities of genetically modified zebrafish. Assays to examine the functionality of the excretory organs can also be modeled in vivo with the zebrafish. The approach of using these multiple techniques in zebrafish not only enables rapid and efficient investigation of candidate genes for lower urinary tract malformations derived from human data, but also cautiously allows transferability of causality from a non-mammalian vertebrate to humans.

Relation between blood levels of heavy metals and some markers of oxidative stress among boys with neuropathic bladder and posterior urethral valve

BACKGROUND

The status of heavy metals in children with lower urinary tract pathology that may harm the upper tract, e.g., neuropathic bladder and posterior urethral valve and its relationship with oxidative stress has not been adequately investigated. Therefore, the object of the current work was to evaluate the concentrations of copper, zinc, cadmium and lead and their relations with levels of catalase (CAT), malondialdehyde (MDA) and glutathione (GSH) in boys with neuropathic bladder and posterior urethral valve.

METHODS

Thirty-six children with neuropathic bladder, 35 children with posterior urethral valve and 33 health controls were included in the study. In addition to routine laboratory tests, blood samples were collected from patients and controls to assess levels of Cu, Zn, Cd and Pb in addition to plasma concentrations of CAT, MDA and GSH.

RESULTS

Significantly elevated levels of Cu, Pb, CAT, MDA and GSH and significantly lower concentration of blood Zn were found in the studied groups compared to the controls. In the posterior urethral valve group, blood level of Cu was positively correlated with GSH while a significantly negative relation was observed between blood Zn and CAT activity among the neuropathic bladder patients.

CONCLUSION

Neuropathic bladder and posterior urethral valve may lead to abnormalities in the blood levels of heavy metals (i.e. Cu, Pb and Zn) and markers of oxidative stress (CAT, MDA and GSH). Therefore, the levels of theses metal ions should be monitored during the treatment course of neuropathic bladder and posterior urethral valve patients to prevent or minimize long-term oxidative injury.

The Pseudo-Bladder: A Case of the Prostatic Urethra Masquerading as the Bladder

Congenital bladder underdevelopment has detrimental genitourinary effects. We present a male infant with declining renal function, recurrent urinary tract infections, and epididymo-orchitis, in the setting of bilateral high grade hydronephrosis and vesicoureteral reflux. Cystoscopic evaluation revealed the presumed "bladder" to be a massively dilated prostatic urethra. The small dysplastic "true bladder" was found at the anterior surface of the prostatic urethra with massively dilated ureteral orifices. Temporizing diversion was performed in the form of bilateral cutaneous ureterostomies, with an ultimate plan for reconstructive bladder surgery. This case presents diagnostic challenges utilizing current modalities due to a massively dilated prostatic urethra in the rare case of bladder dysplasia.

Disease mechanisms of monogenic congenital anomalies of the kidney and urinary tract American Journal of Medical Genetics Part C

Congenital Anomalies of the Kidney and Urinary Tract (CAKUT) is a developmental disorder of the kidney and/or genito-urinary tract that results in end stage kidney disease (ESKD) in up to 50% of children. Despite the congenital nature of the disease, CAKUT accounts for almost 10% of adult onset ESKD. Multiple lines of evidence suggest that CAKUT is a Mendelian disorder, including the observation of familial clustering of CAKUT. Pathogenesis in CAKUT is embryonic in origin, with disturbances of kidney and urinary tract development resulting in a heterogeneous range of disease phenotypes. Despite polygenic and environmental factors being implicated, a significant proportion of CAKUT is monogenic in origin, with studies demonstrating single gene defects in 10%-20% of patients with CAKUT. Here, we review monogenic disease causation with emphasis on the etiological role of gene developmental pathways in CAKUT.

Experience with the use of mohan's valvotome for posterior urethral valve ablation at a centre in North-Eastern Nigeria

INTRODUCTION

Posterior urethral valve (PUV) is the most common congenital cause of lower urinary tract obstruction in boys. Management has remained challenging in our region, with features of renal impairment evident in some patients at the time of presentation. Endoscopic valve ablation is the gold standard of treatment, but this is not readily available in our setting. Mohan's valvotome has been described as an alternative device for valve ablation. This study aimed to highlight the clinical presentation, management and early outcomes following valve ablation using Mohan's valvotome.

METHODS

A retrospective study of boys with PUVs managed between September 2014 and June 2018 was done. The demographic characteristics, clinical features, investigations, treatment and initial outcomes were reviewed. The main outcome measures were improved post-ablation urinary stream, serial serum creatinine values at presentation, 4-5 days of initial catheter drainage and at follow-up.

RESULTS

There were ten boys with the median age at presentation of 4 months (mean: 23.9 months; range 10 days to 7 years). Four patients presented after 1 year. All the patients had features of bladder outlet obstruction with associated fever in seven patients and urinary tract infections in six patients. Nine patients (90%) had suprapubic masses, while 2 had ballotable kidneys with co-existing urinary ascites in one patient. Valve ablation was achieved with Mohan's valvotome. There was a significant improvement in the urine stream in all patients. The median duration of follow-up was 7.5 months. Median serum creatinine was 0.95 mg/dl (mean 0.94 mg/d ± 0.38 mg/dl) at follow-up, compared to a median of 4.03 mg/dl at presentation (P = 0.01).

CONCLUSION

Initial drainage and definitive valve ablation with Mohan's valvotome is associated with improved serum creatinine and urinary stream.

Abdominal distension and lower extremity edema

Posterior urethral valves are a congenital malformation in males that results in the obstruction of urinary outflow from the proximal urethra. Presentation depends on severity of disease, with patients presenting antenatally with oligohydramnios and hydronephrosis, to postnatally with delayed or poor voiding, urinary tract infections, or renal anomalies on ultrasound. Our case illustrates an 11-day-old male who presented to the emergency department with poor feeding, vomiting, significant abdominal distension, and pitting edema of the lower extremities. The patient was found to have hypoglycemia, hyponatremia, hyperkalemia, and acute renal failure. Point of care ultrasound showed severe bilateral hydronephrosis with a significantly distended bladder that was compressing the inferior vena cava. Early recognition of the obstruction via ultrasound led to rapid decompression of the bladder using catheterization and immediate involvement of urology, nephrology, and neonatology consults in the pediatric emergency department.

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.

Prenatally diagnosed lower urinary tract obstruction: A 15-year experience at two tertiary centers in Japan

AIM

To examine the outcomes of prenatally diagnosed lower urinary tract obstruction (LUTO) with current management using vesicoamniotic shunting (VAS).

METHODS

A retrospective study of prenatally diagnosed LUTO before 26 weeks of gestation at two tertiary centers in Japan between March 2002 and September 2017. LUTO was diagnosed by ultrasound demonstration of an enlarged fetal bladder associated with hydronephrosis and/or hydroureters. VAS was offered for fetuses with LUTO at ≤26 weeks of gestational age, in the presence of oligohydramnios or decreasing amniotic fluid and a favorable fetal urinary analysis.

RESULTS

Among 87 fetuses with LUTO, 46 (53%) were terminated before 22 weeks of gestation. Eight cases (9%) underwent VAS and one underwent fetoscopic urethrotomy. The live birth rates in the VAS and expectant groups were 100% (8/8) and 56% (18/32), respectively (p = 0.034), and the survival rates at 6 months old with a normal renal function were 38% (3/8) and 16% (5/32), respectively (p = 0.608). The etiology varied with six cases of associated anomalies among 23 diagnosed cases. Among the nine cases of posterior urethral valve (PUV), only one fetus underwent VAS at 25 weeks of gestation, ultimately surviving with mild renal dysfunction. Among the other eight cases of PUV that were managed expectantly, two died, and only one of the six survivors showed a normal renal function.

CONCLUSIONS

More than half of the prenatally diagnosed LUTO cases were terminated. VAS seemed effective for achieving a perinatal survival, regardless of etiology. The outcomes were poor in cases of expectantly managed PUV.

Delayed Presentation of Urethral Valves: A Diagnosis That Should Be Suspected Despite a Normal Prenatal Ultrasound

Background. Congenital urethral obstruction occurs most frequently as a result of urethral valves. The diagnosis is usually confirmed pre- or neonatally. Though not ideal, delayed diagnosis can occur in childhood, adolescence, or adulthood. Despite a normal prenatal ultrasound, there may still be a delayed diagnosis of urethral valves. Methods. We present 4 patients with delayed diagnosis of posterior urethral valves (PUV) and 1 patient with delayed diagnosis of anterior urethral valves (AUV) who were evaluated by a pediatric urologist at our Institution. We determined the age and symptoms at presentation, physical examination, micturating cystourethrogram (MCU) findings prior to the valve ablation, renal function before and after valve ablation, type of valve ablation, and urine culture and sensitivity. The urological courses following urethral valve ablation including urodynamic study findings are described. Results. The median age at presentation was 33 months. All 5 patients presented with decreased urine output and urinary retention. All 5 patients underwent a MCU that demonstrated bladder trabeculations (3 cases), vesicoureteral reflux (3 cases), and bladder diverticula (2 cases). A urethral valve ablation was performed in all cases. Four patients underwent a renal function panel prior to this procedure, and their serum BUN/creatinine levels decreased 1 day postoperatively. Conclusion. Pediatricians should consider urethral valves as causing urethral obstruction although the prenatal ultrasound may be normal. Early diagnosis and prompt treatment of urethral valves may mitigate the potentially devastating morbidities such as renal failure, congestive heart failure, and respiratory distress that may ensue.

Modeling the nexus between pollutant emission, energy consumption, foreign direct investment, and economic growth: new insights from China

Most nations are predominately preoccupied with the need to increase economic growth amidst pressure for increased energy consumption. However, higher energy consumption from fossil fuel has its environmental implication(s) especially in a high industrial economy like China. In this context, the current study explores the interaction between pollutant emission, foreign direct investment, energy consumption, tourism arrival, and economic growth for quarterly frequency data from 1995Q1 to 2016Q4 for econometrics analysis. Pesaran's autoregressive distributed lag-bound test traces long-run relationship between all outlined variables over the investigated period. Empirical results show positive relationship between pollutant emissions with all other variables with the exception of economic growth. This further exposes the environmental degradation in China with the curtailing strength from the GDP. The Granger causality analysis detects that CO₂ emissions and energy consumption show a two-way causality observed. Also, one-way causality existing between growth and foreign direct investment is seen running to pollutant emission. Furthermore, one-way causality is observed among foreign direct investment, energy consumption, pollutant emission, and tourism arrivals with economic growth, and this established their impact on the economic growth which will be a guide to the policy implication on how to ameliorate environmental degradation from the effect of consumption of fossil energy sources and foreign direct investment-induced pollutant emission.

Short-Term Outcomes of Treatment of Boys with Posterior Urethral Valves

Background:

Posterior urethral valve (PUV) is a significant cause of morbidity and mortality among male children resulting in renal failure in 25%–30% before adolescence irrespective of initial treatment. This study aimed at evaluating the early outcomes of children managed for PUV.

Materials and Methods:

This was a prospective study of all children who were treated for PUV between 2012 and 2016 at a single referral institution. Information reviewed included demographic and clinical data, imaging findings, pre- and post-operative serum electrolytes, and postoperative renal outcomes.

Results:

Twenty-nine male children were managed for PUV at a median age of 6 months including 7 (24.1%) neonates. Two (6.9%) patients had antenatal diagnosis. Micturating cystourethrogram confirmed PUV in all patients. Fourteen (48.3%) patients had impaired renal function (IRF) at presentation and 8 (57%) had improved renal function (RF) after initial catheter drainage. The mean creatinine at presentation was 1.86 ± 1.69 mg/dl and the mean serum creatinine following initial catheter drainage was 0. 93 ± 0.49 mg/dl (P = 0.003). For those patients with normal RF, the mean creatinine at presentation was 0.81 ± 0.22 mg/dl versus 0.74 ± 0.21 mg/dl (P = 0.012), following initial catheter drainage. Children with IRF on admission had mean creatinine at presentation of 2.61 ± 2.00 mg/dl compared to 1.17 ± 0.53 mg/dl (P = 0.002) after initial catheter drainage. Valve ablation was achieved with Mohan's valvotome in 26 (96.3%) patients. All patients had good urine stream at a median follow-up of 5 months. Four (13.8%) patients developed IRF at follow-up. Renal outcomes of patients presenting before 1 year and those presenting after 1 year were similar. Two children died preoperative of urosepsis and one out of hospital death given an overall mortality of 10.3% (n = 3).

Conclusion:

There was significant improvement in RF after initial catheter drainage. The incidence of IRF at follow-up was 13.8%. Long-term follow-up is necessary to identify patients at risk of end-stage renal disease.

Outcome of posterior urethral valve in 64 children: a single center's 22-year experience

BACKGROUND

Posterior urethral valve (PUV) is the most serious form of congenital anomalies of kidney and urinary tract (CAKUT) in boys with significant risk of progression to chronic kidney disease (CKD). We present our long-term results in children with PUV.

METHODS

Retrospective chart review of 113 children with PUV followed within the years of 1996-2018 was performed. Clinical, laboratory and epidemiologic parameters were analyzed for their impact on renal outcome.

RESULTS

The median age of diagnosis was 1.00 month (1.00-132.00) and the median follow-up period was 70 months (60.00-216.00). Antenatal diagnosis was present in 33 patients (51.5%) mainly with bilateral hydronephrosis and oligohydramnios. The most common postnatal presentation was recurrent urinary tract infection (UTI) in 14 cases (21.9%) and incontinence in three cases (4.7%). Vesicoureteral-reflux (VUR) was present in 31 cases (48.4%). All patients had surgery and urinary diversion was needed in 18 (28.2%). Varying stages of chronic kidney disease (CKD) developed in 23 cases (35.9%) and rise in serum creatinine was especially prominent after the 4th year of follow-up. Of 23 CKD patients, seven (10.9%) were in ESRD and on dialysis. Mortality occurred in one (1.5%) patient. Hypertension, proteinuria and high initial serum creatinine (>1.28 mg/dL) were statistically significant risk factors for CKD, as expected. Surprisingly VUR and UTI did not show such a significant impact on CKD development. Antenatal detection was with significantly less risk for CKD.

CONCLUSIONS

Our results confirm that PUV has a considerable risk for CKD development. Antenatal diagnosis, management of proteinuria and hypertension may modify this progression. But already injured kidneys still have a potential risk. The need for further research to evaluate the impact of any intervention on long term renal outcome is obvious.

Neonate with urinary ascites but no hydronephrosis: unusual presentation of posterior urethral valves

Posterior urethral valves (PUV) are an important cause of paediatric obstructive uropathy. PUV are usually diagnosed by prenatal ultrasonography (US) revealing hydronephrosis and bladder distention. We describe a 17-day-old male infant with abdominal distention who had no hydronephrosis on prenatal US. Laboratory investigations showed serum creatinine of 12 mg/dL, hyperkalaemia and metabolic acidosis. Abdominal US showed large amount of ascites, normal-sized kidneys without hydronephrosis and incompletely distended bladder. Paracentesis revealed clear, yellow ascitic fluid with creatinine level of 27 mg/dL compatible with urinary ascites. Voiding cystourethrogram (VCUG) demonstrated PUV with a dilated posterior urethra, grade 5 right vesicoureteral reflux and a ruptured kidney fornix with peritoneal extravasation of contrast. Foley decompression resulted in normalisation of creatinine within 72 hours. Transurethral resection of PUV was performed, and a repeat VCUG showed recovery of forniceal rupture. This case illustrates an unusual presentation of a potentially life-threatening but treatable cause of urinary tract obstruction.

Posterior urethral valves: 10 years audit of epidemiologic, diagnostic and therapeutic aspects in Yaoundé gynaeco-obstetric and paediatric hospital

BACKGROUND

The incidence of posterior urethral valve (PUV) is estimated at 1:5000-1:8000 males. It is the most common paediatric urologic urgency and the most common cause of male obstructive uropathy and chronic renal failure in children. The study aimed to describe the experience of Yaoundé gynaeco-obstetrics and paediatric hospital in the management of PUV.

METHODS

Retrospectively, medical records were retrieved over a ten year period and all data recorded and analyzed for study objectives. Patients were called and evaluated for outcomes regarding morbidity and mortality.

RESULTS

A total of 18 patients all males were managed over the ten year period, given prevalence of 13 cases/100,000 admissions and an admission rate of 2 per annum. The median age at presentation was 22 months and 13 (72.2%) participants presented late. Voiding urethrocystogram was done in all the participants where it showed dilated and elongated posterior urethral valves in 16 (88.9%) of the cases. Endoscopic valve ablation resulted in the relief of obstruction in all but 3 (16.7%) participants that had residual valves and 2 (11.2%) participants that had urethral stenosis. Type I valves were most common in 14 (78.0%) participants. The mean duration of follow up was 34.56 ± 21.47 months. Complications at final follow up were: 10 (55.6%) chronic renal failure, 2 (11.2%) end-stage renal failure. The case fatality rate was 5.6%.

CONCLUSION

Many patients present late in our setting with already established complications. There is the need to counsel parents/guardians on the importance of long-term follow up after relief of obstruction.

Novel Insights into the Pathogenesis of Monogenic Congenital Anomalies of the Kidney and Urinary Tract

Congenital anomalies of the kidneys and urinary tract (CAKUT) comprise a large spectrum of congenital malformations ranging from severe manifestations, such as renal agenesis, to potentially milder conditions, such as vesicoureteral reflux. CAKUT causes approximately 40% of ESRD that manifests within the first three decades of life. Several lines of evidence indicate that CAKUT is often caused by recessive or dominant mutations in single (monogenic) genes. To date, approximately 40 monogenic genes are known to cause CAKUT if mutated, explaining 5%-20% of patients. However, hundreds of different monogenic CAKUT genes probably exist. The discovery of novel CAKUT-causing genes remains challenging because of this pronounced heterogeneity, variable expressivity, and incomplete penetrance. We here give an overview of known genetic causes for human CAKUT and shed light on distinct renal morphogenetic pathways that were identified as relevant for CAKUT in mice and humans.

Posterior urethral valves: Impact of low birth weight and preterm delivery on the final renal outcome

Objective

To investigate the relationship between low birth weight (LBW; <2.5 kg) and preterm delivery (<37 weeks gestational age) and final renal outcome in infants with posterior urethral valves (PUVs), emphasising the risk factors for the development of chronic kidney disease (CKD).

Patients and methods

A retrospective review was performed for all infants with PUVs who were treated between 1990 and 2010. In all, 52 infants were identified to have LBW and/or delivered preterm (Group 1). Infants in Group 1 were compared with a matching group (Group 2) of 60 full-term normal birth weight (NBW) infants with PUVs managed during the same period. The outcome of both groups was analysed.

Results

During follow-up, CKD developed in 17 (32.5%) and 22 patients (36.5%) in Groups 1 and 2, respectively (P = 0.812). Patients with LBW or delivered preterm had significantly higher incidence of oligohydramnios (P = 0.009), increased risk of vesicostomy (P < 0.001), longer hospital stay (P < 0.001), and higher incidence of vesico-ureteric reflux (VUR, P = 0.024). In the LBW patients, initial serum creatinine, nadir serum creatinine, oligohydramnios and Neonatal Intensive Care Unit (NICU) length of stay were significant predictors of final renal outcome (P < 0.001, P = 0.002, P = 0.004 and P = 0.012, respectively).

Conclusion

In our cohort of LBW and preterm delivery infants with PUVs, outcomes were similar to those of NBW full-term infants with PUVs but with an increased risk of vesicostomy, longer hospital stay, and higher incidence of VUR. LBW was associated with oligohydramnios, longer NICU admission, high initial and nadir serum creatinine, which were associated with a poor prognosis.

Refractory Urinary Incontinence in Girls: The Role of the Bladder Neck

BACKGROUND

Prevalence of lower urinary tract dysfunction (LUTD) in children is between 6 and 9% with urinary incontinence (UI) being one of the most common symptom.

VARIOUS ASPECTS OF LOWER URINARY TRACT SYMPTOMS LUTS

Anatomical anomalies of the urinary tract as well as neurogenic underlying pathology can results in LUTS. Comorbidities and long-term consequences of the LUTD for the female patients as well as genetic issues are also briefly discussed.

THE ROLE OF THE BLADDER NECK

Thanks to urodynamics, we have learnt a lot about the lower urinary tract function, but the role of the bladder neck in the pathophysiology of LUTS in children is not clear. Secondary bladder neck hypertrophy is a well-described pathology, but there is no standardized treatment for this phenomenon. Primary bladder neck dysfunction has already been defined by the International Children's Continence Society.

REFRACTORY UI IN GIRLS

Uniform diagnostic protocols are used in these girls with UI. Treatment consists of standard urotherapy, additional interventions, and pharmacotherapy in selected cases. Those with refractory UI require careful reassessment to look for the unrecognized disorders. Invasive urodynamics should be done in those patients. Ultrasound of the bladder neck region and the pelvic floor can be helpful, but its interpretation is very subjective. In a small group bladder neck insufficiency can be found and those might benefit from a surgical intervention.

FUTURE PERSPECTIVE

Strict criteria of the bladder neck insufficiency in children must be defined. Early surgical intervention in girls with bladder neck insufficiency might reduce the long period of intensive conservative treatment.

Long-term Impacts of Concurrent Posterior Urethral Valve Ablation and Bladder Neck Incision on Urinary Continence and Ejaculation

OBJECTIVE

To assess the long-term impacts of bladder neck incision (BNI) on continence and ejaculatory function of adults who underwent concurrent posterior urethral valve (PUV) ablation and BNI during childhood.

MATERIALS AND METHODS

A retrospective chart review was performed to find all adult patients with relevant history. All patients had undergone BNI at 6 o'clock proximal to the verumontanum with caution to leave the adventitia and verumontanum untouched. Charts were reviewed and attempts were made to contact those ≥18 years old for follow-up. Patients were specifically evaluated for lower urinary tract symptoms and ejaculatory condition.

RESULTS

Among patients treated for PUV between 1998 and 2015 in our center, 21 were ≥18 years old at the time of assessment. Until February 2016, we were able to contact 18 patients, all of whom agreed to participate. Mean age was 21.1 ± 2.9 years with a mean follow-up of 12.5 ± 4.8 years. None of those contacted had incontinence or dry ejaculations. All considered their ejaculations normal and only one complained of weak ejaculations. Four of 5 patients who consented to perform a semen analysis had normal tests and 1 had low sperm count with abnormal motility.

CONCLUSION

BNI is not associated with additional risk of incontinence and dry ejaculation in early adulthood and preserves antegrade ejaculation. Concomitant valve ablation with BNI may provide additional benefits in care of PUV children, especially those with prominent bladder neck and poor bladder function at presentation.

Ultrasonography of hydronephrosis in the newborn: a practical review

Widespread use of fetal ultrasonography is accompanied by more frequent detection of antenatal hydronephrosis. Therefore, sonographic evaluation of neonates with a history of antenatal hydronephrosis is becoming more widespread. As an initial postnatal non-invasive imaging modality, ultrasonography is used to screen for persistence of hydronephrosis, determine the level and severity of obstruction, and contribute to appropriate diagnosis and treatment. This review aims to provide a practical overview of the sonographic evaluation of neonatal hydronephrosis and to describe the sonographic findings of conditions associated with hydronephrosis in the newborn.

Vesicostomy and Colostomy in a Premature Neonate With Posterior Urethral Valves, Bilateral Dysplastic Kidneys, and High Imperforate Anus: The Challenge of Stoma Placement

Although anorectal malformations are often associated with urinary tract abnormalities, the association with posterior urethral valves is exceptionally rare. We report a unique case of a premature (35 gestational weeks) male neonate born with posterior urethral valves, bilateral dysplastic kidneys, and imperforate anus, successfully treated by Blocksom vesicostomy and left upper quadrant loop colostomy. The challenges involving placement of both stomas in a small abdominal wall of a 2200 g premature neonate are discussed.

Posterior Urethral Valves in Children: Pattern of Presentation and Outcome of Initial Treatment in Ile-Ife, Nigeria

Background:

The management of posterior urethral valves (PUV) and its sequelae is still a challenge to most pediatric surgeons in our environment due to late presentation and inadequate facilities for long-term evaluation and treatment. Despite initial successful treatment about 40% would develop chronic renal failure. The aim is to describe the presentation, management and outcome of the initial treatment in boys with PUV.

Materials and Methods:

It is a retrospective analysis of PUV in boys 8 years and below over a 17 years period. Demographic characteristics, clinical features, investigations, and treatment outcome were reviewed.

Results:

Thirty-seven cases were analyzed. The median age was 5 months (range from birth to 8 years). Three (8.1%) patients had prenatal ultrasound diagnosis. The most common presentation was voiding dysfunction 37 (100%). Part of the preoperative investigation included micturating cystourethrogram (n = 31: 83.8%) and abdomino-pelvic ultrasonography (n = 37:(100%). The mean serum creatinine value of those who presented within the first 30 days of life and those who presented afterwards were 325 (±251) µmol/L and 141 (±100) µmol/L respectively, P = 0.003. Surgical interventions included trans-vesical excision of valves (n = 9: 28.1%), valvotomy (n = 10: 31.3%), balloon avulsion (n = 8: 25.0%), vesicostomy (n = 4: 12.5%) and endoscopic valve avulsion (n = 1: 3.1%). Seventeen (56.7%) patients had serum creatinine >70.4 µmol/L after 1-month of valve excision. Five (13.5%) patients had postrelief complications and 5 (13.5%) died on admission. Ninety percentage (27/30) of patients had poor prognostic indices.

Conclusions:

The initial treatment outcome was good but most had poor prognostic factors.

Posterior urethral valves: Metabolic consequences in a cohort of patients

BACKGROUND

Despite the improvements in diagnosis and management of posterior urethral valves (PUVs), about one third of patients develop chronic kidney disease (CKD). Children with PUVs might have abnormal calcium, phosphorus, vitamin D and parathyroid hormone levels, which could affect their bone growth and overall health.

OBJECTIVE

The aim was to determine the relationship between kidney function, vitamin D deficiency and secondary hyperparathyroidism in children with PUVs.

PATIENTS AND METHODS

Sixty-four children with PUVs were followed for a period of 3.64 ± 2.50 years after their initial presentation and management. Their laboratory parameters were compared with 20 age-, gender- and race-matched children in a control group, including: serum calcium, phosphorus, intact parathyroid hormone (iPTH), 25-hydroxyvitamin D levels, and kidney function.

RESULTS

Children with PUVs had significantly lower estimated kidney function (P = 0.006) and vitamin D levels (P < 0.001) and higher iPTH levels (P = 0.042). There were no significant between-group differences in serum calcium, phosphorus, alkaline phosphatase, sodium, potassium, and bicarbonate levels. There was a strong correlation between the degree of vitamin D deficiency and hyperparathyroidism and the degree of kidney dysfunction (r = 0.52 and -0.52, respectively) in the PUV group. On a multivariate analysis, the kidney dysfunction was the only independent predictor of vitamin D deficiency (ρ = 0.271, P < 0.001), while kidney dysfunction, serum calcium and alkaline phosphatase were independent predictors for hyperparathyroidism (ρ = 0.925, P<0.001, ρ = 0.933, P<0.001 and ρ = 0.913, P < 0.001, respectively).

DISCUSSION

The prevalence of CKD in children with PUVs ranges from 30 to 60%. Patients with CKD are more likely to have vitamin D deficiency and display more-prominent hyperparathyroidism. Compared with a control group with normal kidney function, the present cohort had lower 25-hydroxyvitamin D and higher iPTH serum levels. Abnormal kidney function was a major predictor for both serum levels. In this cohort, there were no significant differences in serum calcium and phosphorus between children with PUVs and the control group, and also between those with and without CKD. On the contrary, vitamin D level decreased early in the disease and progressively declined thereafter, while iPTH was the opposite. These findings were comparable to previous studies. This study had some limitations because it was a single center cross-sectional non-randomized study. However, the findings in this study can be extrapolated to children with PUVs and CKD from other origins because the unit is considered as a referral center in the Middle East region.

CONCLUSION

Abnormal kidney function, vitamin D deficiency, and secondary hyperparathyroidism are prevalent in children with PUVs. Kidney function is the main determinant of vitamin D and parathyroid hormone levels. Efforts should be directed toward managing CKD, and controlling vitamin D deficiency and hyperparathyroidism in children after ablation of PUV.

Proteomic urinary biomarker approach in renal disease: from discovery to implementation

Biomarkers hold the promise of significantly improving health care by enabling prognosis and diagnosis with improved accuracy, and at earlier points in time. Previous results have indicated that single biomarkers are not suitable to describe complex diseases such as kidney disease. Here we provide an update on the progress of urinary proteomics-based studies and strategies to develop biomarker-based classifiers that tolerate instability and inconsistency of individual biomarkers. The examples focus on two major fields in nephrology: chronic kidney disease in the adult population and obstructive nephropathies in the pediatric population. When employed adequately, urinary proteomics demonstrates a clear value in kidney disease, indicating that the current status quo ruling for decades now could be changed by applying modern "omics" approaches. However, while research is able to deliver these useful tools for patient management, the issues associated with implementation are not yet solved. Active engagement of the relevant clinical professional societies, as well as patient's organizations, might help to implement these omics approaches that have shown a clear benefit for the patient.

Posterior urethral valve with unilateral vesicoureteral reflux and patent urachus: A rare combination of urinary tract anomaliess

Posterior urethral valve (PUV) is a common cause of lower urinary tract obstruction in male infants with an incidence of 1:5000-8000. PUV continues to be a significant cause of morbidity and ongoing renal damage in infants and children. It can coexist with vesicoureteral reflux (VUR) in about 50% of cases and also with patent urachus in about one-third of cases. It is a case of a 22-day-old full-term male child who presented with poor urinary stream and progressive abdominal distension of 5-day duration as well as leakage of clear fluid from umbilicus of 1-day duration. Abdominopelvic ultrasonography showed bilateral hydronephrosis. Micturating cystourethrogram also showed features of bladder outlet obstruction and PUV. In addition, a grade V left VUR and a fistulous tract between the dome of the urinary bladder and the umbilicus, which was consistent with a patent urachus was demonstrated. In conclusion, this case demonstrates a rare combination of congenital urinary tract anomalies involving PUV, left VUR and patent urachus.

Presentation, management, and outcome of posterior urethral valves in a Nigerian tertiary hospital

BACKGROUND

Posterior urethral valves (PUV) remain the most common cause of bladder outlet obstruction and renal insufficiency in male children. The aim of this study was to evaluate the presentation, management, challenges, and outcome of the disease in a Nigerian tertiary health institution.

PATIENTS AND METHODS

Retrospectively, medical records of male children with a diagnosis of PUVs over a 10 year period (2003-2012) were retrieved. All data in relation to the study objectives were recorded and analyzed.

RESULTS

A total of 44 patients was managed for PUV within the period. The mean age of presentation was 3.95 years with 56.8% of the patients presenting after the age of 1 year. Voiding dysfunction noted in 40 (91.0%) patients was the most common mode of presentation. The most common finding on physical examination was a palpable bladder while urinary tract infection noted in 23 (52.3%) patients was the most common complication noted. Abdominal ultrasonography revealed dilated posterior urethra in 16 (36.4%) cases, while micturating cystourethrogram revealed a dilated proximal urethra in all 35 cases in which it was done, diverticulum in 6 and vesicoureteric reflux in 9. The creatinine value at presentation ranged between 0.4 mg/dl and 4.0 mg/dl with a mean of 1.02 ± 0.93 mg/dl. Urethroscopy in 37 patients confirmed type I and type III PUV in 35 and 2 patients, respectively. Valve ablation with a diathermy bugbee electrode provided relief of obstructions in the 37 patients who underwent the procedure without any significant immediate complication. The period of follow-up ranged between 2 weeks and 3 years with a mean of 10.2 months. There was sustained improvement in urine stream, reduction in the mean creatinine concentration and incidence of UTI during follow-up. However, patients with significantly impaired renal function had a poorer outcome.

CONCLUSION

Many patients with PUV presented late within the reviewed period. Valve ablation provided relief of obstruction in most of the cases. There is a need to counsel parents/guardians on the need for long-term follow-up.

Laser ablation in the management of obstructive uropathy in neonates

INTRODUCTION

Endoscopic management of posterior urethral valves and congenital ureteroceles is the current standard to relieve the obstruction. While the most commonly used techniques involve cystoscopic incision with cold knife or electrosurgery, an alternative is to ablate the obstructive tissue with laser energy. With increasing prenatal diagnoses, there has been an increasing shift in the timing of intervention toward earlier periods. The literature contains only two reports of laser ablation in neonates for these disease entities.

MATERIALS AND METHODS

A case series was conducted by retrospectively reviewing our surgical database for all consecutive infants <28 days old (i.e., neonates) diagnosed in utero with obstructive uropathy and with postnatal imaging consistent with either urethral valves (anterior or posterior) or ureterocele. Holmium: yttrium aluminum-garnet (Ho:YAG) laser ablation was used as the exclusive modality of endoscopic management during the study period. All patients were followed with voiding cystourethrogram and renal/bladder ultrasounds postoperatively.

RESULTS

Seventeen neonates underwent retrograde transurethral laser ablation procedures at a median age of 7 days (range 3-27). There were nine cases of urethral valve ablation (seven posterior, two anterior) and eight ureterocele ablations. Median operative time was 23 minutes (range 18-33). There were no intraoperative complications or reoperative procedures required for any case. All patients voided after postoperative catheter removal, and no patient had evidence of residual valve tissue or urethral stricture at mean follow-up of 10.1 months. All patients with ureterocele demonstrated partial or complete decompression of the ureterocele and improvement in hydroureteronephrosis at 3 months.

CONCLUSIONS

Ho:YAG laser ablation appears safe, effective, and efficient for the management of urethral valves and ureteroceles in the neonatal period. With a continuing trend toward early definitive intervention for these conditions, laser ablation remains an important alternative to electrosurgery in this population.

Role of vesicostomy in the management of posterior urethral valve in Sub-Saharan Africa

OBJECTIVE

To review the role of vesicostomy in the management of posterior urethral valve (PUV), in neonates and infants, given the limitations for endoscopic treatment in this setting.

METHODS

A review of 35 patients who presented with posterior urethral valve over a 10-year period. Demographic and clinical information were prospectively recorded on a structured pro forma, and the data extracted analysed using SPSS 11.0.

RESULTS

The 35 boys were aged 3 days to 10 years (median 3 weeks). Twenty-three (65.7%) had a vesicostomy (age range 3 days-3 years, median 3 weeks). The mode of presentation was poor urinary stream 15 (65.2%), urinary retention 4 (17.4%), and renal failure 6 (26.1%). Main findings were palpable bladder 23 (100%), hydronephrosis 4 (17.4%). Abdominal ultrasound confirmed hydronephrosis and thickened bladder wall, and voiding/expressive cystourethrogram confirmed dilated posterior urethra and vesicoureteric reflux in all 23 patients. Complications following vesicostomy were stoma stenosis 1 (4.3%), bladder mucosal prolapse 1 (4.3%), perivesicostomy abscess 1 (4.3%); there was no mortality. Following vesicostomy, 10 (43.5%) patients had excision of the valves and vesicostomy closure at age 2-8 years (median 4 years). They are well, with normal renal ultrasonographic findings, bladder capacity range 115-280 ml, and normal urea, serum electrolytes, creatinine, at 3 years of follow up. Thirteen (56.5%) are still awaiting valvotomy but have remained well and with normal ultrasonographic renal findings.

CONCLUSION

Vesicostomy is a useful temporising mode of urinary diversion in neonates and infants with posterior urethral valve (in the absence of unobstructed upper tracts) when facilities for endoscopic valve ablation are not readily available.

Which patients are at higher risk for residual valves after posterior urethral valve ablation?

Purpose

To find patients at high risk of obstructive remnant leaflets after valve ablation among boys with posterior urethral valve (PUV), we evaluated any possible relationship between preoperative findings in our patients and residual obstructive leaflets after valve ablation.

Materials and Methods

We retrospectively reviewed the medical records of 55 patients with PUV that was treated by the same surgeon between 2008 and 2012. Of these, 37 patients (67.3%) had no obstructive remnant leaflets (group A) and 18 patients (32.7%) had obstructive remnant leaflets (group B) in follow-up cystoscopy. Preoperative clinical and radiological findings were evaluated and compared between the groups.

Results

Among all the preoperative data we examined, the analysis revealed that age at the time of surgery (median age: group A, 15 months; group B, 7 months; p=0.017), echogenicity of kidneys (p<0.05), presence of vesicoureteral reflux (p<0.05), and grade of reflux (p<0.05) were significantly different between the groups. Method of valve ablation, anterior-posterior diameters of the renal pelvis, renal cortical thickness, bladder wall thickening, and scarring on the dimercaptosuccinic acid scan showed no significant differences between the two groups.

Conclusions

In our patients, younger age at surgery time, hyperechogenicity of renal parenchyma, presence of vesicoureteral reflux, and grade 4 or 5 reflux before surgery had a significant relationship with residual valves. More studies may result in enhanced management of patients at high risk of residual valves after PUV ablation, because the sooner the obstruction is resolved entirely, the better the outcome.

Clinical proteomics in obstetrics and neonatology

Clinical proteomics has been applied to the identification of biomarkers of obstetric and neonatal disease. We will discuss a number of encouraging studies that have led to potentially valid biomarkers in the context of Down's syndrome, preterm birth, amniotic infections, preeclampsia, intrauterine growth restriction and obstructive uropathies. Obtaining noninvasive biomarkers (e.g., from the maternal circulation, urine or cervicovaginal fluid) may be more feasible for obstetric diseases than for diseases of the fetus, for which invasive methods are required (e.g., amniotic fluid, fetal urine). However, studies providing validated proteomics-identified biomarkers are limited. Efforts should be made to save well-characterized samples of these invasive body fluids so that many valid biomarkers of pregnancy-related diseases will be identified in the coming years using proteomics based analysis upon adoption of 'clinical proteomics guidelines'.

Renal impairment in children with posterior urethral valves

BACKGROUND

Posterior urethral valves (PUV) are a common cause of end-stage renal failure in childhood. Our aim was to describe a cohort of patients with PUV and to investigate the predictors of renal impairment.

METHODS

We performed a retrospective chart review of children with PUV who were followed at King Abdulaziz University hospital between 2002 and 2011.

RESULTS

The cohort comprised 68 boys. There was a significant difference in the duration of follow-up (p = 0.024), nadir serum creatinine (p < 0.001), and last known serum creatinine level (p = 0.001) between the patients with and without renal impairment. The duration of follow-up appeared to be a significant predictor for serum creatinine doubling (p = 0.003; odds ratio, 1.8). There was no difference in the age of presentation, age at the time of the study, and first or last serum creatinine between children who initially had vesicostomy and children who had ablation.

CONCLUSIONS

Ablation of PUV or vesicostomy did not influence kidney function in our study cohort. Children with a normal nadir serum creatinine who presented early had a better outcome.

Lower urinary tract development and disease

Congenital anomalies of the lower urinary tract (CALUT) are a family of birth defects of the ureter, the bladder, and the urethra. CALUT includes ureteral anomaliesc such as congenital abnormalities of the ureteropelvic junction (UPJ) and ureterovesical junction (UVJ), and birth defects of the bladder and the urethra such as bladder-exstrophy-epispadias complex (BEEC), prune belly syndrome (PBS), and posterior urethral valves (PUVs). CALUT is one of the most common birth defects and is often associated with antenatal hydronephrosis, vesicoureteral reflux (VUR), urinary tract obstruction, urinary tract infections (UTI), chronic kidney disease, and renal failure in children. Here, we discuss the current genetic and molecular knowledge about lower urinary tract development and genetic basis of CALUT in both human and mouse models. We provide an overview of the developmental processes leading to the formation of the ureter, the bladder, and the urethra, and different genes and signaling pathways controlling these developmental processes. Human genetic disorders that affect the ureter, the bladder and the urethra and associated gene mutations are also presented. As we are entering the postgenomic era of personalized medicine, information in this article may provide useful interpretation for the genetic and genomic test results collected from patients with lower urinary tract birth defects. With evidence-based interpretations, clinicians may provide more effective personalized therapies to patients and genetic counseling for their families.

Outcome of late presentation of posterior urethral valves in a resource-limited economy: challenges in management

Delayed presentation of patients with posterior urethral valve with complications like severe urosepsis, uremia, and anemia are seen in our setting. Renal replacement therapy which should have been offered to these patients is not readily available for children in our country. The aim of this study is to determine the pattern of late presentation and outcome of management of posterior urethral valve in a resource-limited setting. A descriptive retrospective study (1997–2009) was conducted. Data including pattern of presentation, duration of symptoms, complications, and outcome of initial management were analyzed. Twenty-one patients were seen. The median age was 3 years (2 days–13 years). The mean duration of symptoms before presentation was 2.6 years. Nineteen patients (91%) presented with urosepsis while 8 patients (36%) presented with significant renal insufficiency. Laboratory findings varied from-mild-to marked elevation in serum creatinine. Radiological findings confirmed the diagnosis of posterior urethral valve. We concluded that late presentation is common in our setting. This is associated with high morbidity and mortality rates. Efforts at improving awareness and early diagnosis among the health team should be made to stem the tide.