Current trends in the management of posterior urethral valves in the pediatric population

Ultrasound for the evaluation of the urethra in pediatric patients

Urethral lesions in pediatric patients can be visualized using ultrasonography. Therefore, sonographers and physicians should be familiar with the technique.

Thulium Laser for the Treatment of Posterior Urethral Valves in Infants

Objective: Thulium laser (ThL) has become popular in urology, because of its powerful action on tissue, achieving optimal ablation and hemostasis. Aim of our article was to evaluate efficacy of ThL in infants affected by posterior urethral valve (PUV) ablation. Patients and Methods: Clinical charts of 25 infants (age ≤12 months) who underwent PUV ablation were retrospectively reviewed. According to our protocol, all patients performed voiding cystourethrography and cystoscopy 6 to 8 months after initial treatment. Several factors, including age and weight at surgery, operative time, postoperative bleeding, catheterization period, postoperative urinary retention, retreatment for valve remnants, and stricture at follow-up, were evaluated. Preoperative, intraoperative, and postoperative data were analyzed. Results: Mean age at primary surgery was 4.5 months (5 days-10.5 months) and mean weight at primary surgery was 5.7 kg (2.5-10.3 kg). Mean operative time was 29.5 minutes (range 15-50 minutes). None of the patients experienced intraoperative and postoperative bleeding. In all cases, postoperative catheterization period was 1 day. Residual valves were found in 6 of 25 (24%) patients. No cases of urethral stricture were registered during follow-up (48.4 months, range: 11-95). Analyzing literature data using other techniques, complication rate of ThL PUV ablation seems lower than standard treatments (electrofulguration, cold knife) and comparable with those reported with other laser techniques. Conclusion: PUV ablation with ThL has proven to be feasible and safe in infants. Further studies are needed to define the real effectiveness of this laser technology in PUV ablation. Miniaturized instruments and ThL technology make early PUV treatment feasible also in low body weight newborns.

Infantile versus childhood posterior urethral valve diagnosis: management patterns and clinical outcomes at opposite ends of the spectrum

BACKGROUND

Management patterns and outcomes are poorly defined in cases of late PUV diagnosis.

OBJECTIVE

To compare post-ablation management and clinical outcomes of patients with infantile (<1 year) versus childhood (>5 year) PUV diagnosis to gain insight into the pathologies at opposite ends of the PUV spectrum.

STUDY DESIGN

A multicenter retrospective cohort study was conducted using the TriNetX research network between 2006 and 2022. TriNetX synthesizes insurance claims and electronic medical record data for over 110 million patients from 92 healthcare organizations. We defined two cohorts: 1) The <1 year arm had an index diagnosis of PUV and cystoscopy with valve ablation within 1 year of life, 2) the >5 year arm had an index diagnosis of PUV and valve ablation after age 5. We report rates and time-to-first use of antispasmodics, alpha-blockers, CIC, bladder botox, enterocystoplasty or Mitrofanoff or secondary cutaneous vesicostomy, and CKD.

RESULTS

We identified 569 patients (323 <1 year; 246 >5 year). Median age at diagnosis was 1 month (median follow-up 8 years) and 9 years (median follow-up 10 years) for the <1 year and >5 year cohorts, respectively. Following ablation, both arms were primarily managed with antispasmodics, with no difference between groups. The >5 year arm was significantly more likely to receive alpha-blockers or bladder botox. The <1 year arm was significantly more likely to be started on CIC, undergo enterocystoplasty, Mitrofanoff or secondary cutaneous vesicostomy, or renal transplantation. The <1 year arm had significantly higher rates and shorter time-to-progression to all stages of CKD.

DISCUSSION

Despite higher utilization of conservative strategies among patients with a late PUV diagnosis, these patients had superior renal outcomes and low rates of progression to invasive treatments. Limitations include potential inaccuracies in medical coding as well as variations in thresholds to initiate CIC, perform surgical reconstruction, or proceed with renal transplantation at participating centers.

CONCLUSIONS

These findings provide evidence that a late PUV diagnosis reflects an overall milder disease process.

Renal outcome among children with posterior urethral valve: When to worry?

INTRODUCTION

Posterior urethral valve (PUV) is a congenital obstructive defect of male urethra that is diagnosed early during antenatal period with a presence of hydroureteronephrosis and associated with several morbidities including chronic kidney disease (CKD) that requires management, therefore, this study aim to evaluate the renal outcome of endoscopic valve ablation and urinary tract diversion in children with PUV, "when to worry, and what to do."

METHODOLOGY

This is a retrospective cohort study reviewing medical records of all patients diagnosed with PUV that has been managed in Pediatric Urology Unit at King Abdul-Aziz Medical City, Jeddah in the period of 1998-2008 with proven diagnosis at age younger than 16 accounted for 39 patients, and with different multiple demographics such as antenatal and postnatal ultrasound findings, serum levels of preoperative creatinine, mode of surgical treatment (i.e., endoscopic valve ablation and urinary diversions). Patients were divided into two groups according to the initial surgical intervention. Patient's characteristics and other variables were analyzed; t-test and Chi-square test were used.

RESULTS

During the follow-up period, (45%) developed CKD with a mean time of 5.5 years, 18% reach to end stage renal disease (ESRD), (10%) requiring dialysis. Abnormal creatinine level was detected in 69% (27/39) of our patients before the intervention and normalized in 97% after intervention. In comparison between the two intervention groups, CKD were developed in 60% of patients with urinary diversion in comparison to 33% for the endoscopic ablation group with no statistical significance with P = 0.09. The time to develop CKD was faster in the diversion group with mean age of 18 months (standard deviation [SD] 2 years) in comparison to endoscopic ablation group with mean age 6 years (SD 4 years). Similar results were observed for development of ESRD, patients who underwent diversion had slightly higher incidence of ESRD. In our cohort group, the main determinant for deterioration of the future kidney function was the level of serum creatinine, preoperatively. Moreover, recurrent urinary tract infections (UTIs) were developed in 64% of our cohort group and 49% of our population diagnosed with voiding dysfunction at 6 years of age.

CONCLUSION

A child with PUV who has a risk factor does have an increased potential of developing CKD, knowing that the type of intervention offered to treat PUV has no impact on the outcome. Furthermore, not having any of the study mentioned risk factors doesn't rule out the possibility of developing comorbidities which suggest that any child with PUV always need to be worried about and longer follow-up is indicated. Early intervention, check cystoscopy after ablation, close follow-up with appropriate laboratory and radiological investigation when necessary are recommended, and to improve the quality of data to the level reaching to a meaningful conclusion with high accuracy, a national database system from all centers across the country should be implemented.

<p>Is Endoscopic Transurethral Incision Really Effective for Boys with Refractory Daytime Incontinence?</p>

Purpose

To determine the clinical efficacy of endoscopic transurethral incision (TUI) for boys with refractory daytime incontinence due to a posterior urethral valve with or without nocturnal enuresis.

Patients and Methods

A total of 20 boys with daytime incontinence were assessed. Twelve boys underwent TUI (TUI+ group) and eight boys continued receiving oral drugs (TUI- group). The primary endpoint was the cure rate associated with TUI or NE in both groups.

Results

Only two boys achieved daytime continence 6 months after TUI, but no boys were cured of nocturnal enuresis 6 months after TUI. The median time to daytime continence was significantly longer in the TUI+ than in the TUI- group (52 vs 27 months, respectively; log rank P = 0.041) and the median time to dry nights was significantly longer in the TUI+ than in the TUI- group (56 vs 36 months, respectively; log rank P = 0.021).

Conclusion

TUI might be not effective in boys with refractory daytime incontinence.

The ANTENATAL multicentre study to predict postnatal renal outcome in fetuses with posterior urethral valves: objectives and design

Background

Posterior urethral valves (PUV) account for 17% of paediatric end-stage renal disease. A major issue in the management of PUV is prenatal prediction of postnatal renal function. Fetal ultrasound and fetal urine biochemistry are currently employed for this prediction, but clearly lack precision. We previously developed a fetal urine peptide signature that predicted in utero with high precision postnatal renal function in fetuses with PUV. We describe here the objectives and design of the prospective international multicentre ANTENATAL (multicentre validation of a fetal urine peptidome-based classifier to predict postnatal renal function in posterior urethral valves) study, set up to validate this fetal urine peptide signature.

Methods

Participants will be PUV pregnancies enrolled from 2017 to 2021 and followed up until 2023 in >30 European centres endorsed and supported by European reference networks for rare urological disorders (ERN eUROGEN) and rare kidney diseases (ERN ERKNet). The endpoint will be renal/patient survival at 2 years postnatally. Assuming α = 0.05, 1–β = 0.8 and a mean prevalence of severe renal outcome in PUV individuals of 0.35, 400 patients need to be enrolled to validate the previously reported sensitivity and specificity of the peptide signature.

Results

In this largest multicentre study of antenatally detected PUV, we anticipate bringing a novel tool to the clinic. Based on urinary peptides and potentially amended in the future with additional omics traits, this tool will be able to precisely quantify postnatal renal survival in PUV pregnancies. The main limitation of the employed approach is the need for specialized equipment.

Conclusions

Accurate risk assessment in the prenatal period should strongly improve the management of fetuses with PUV.

Association between the clinical presentation of congenital anomalies of the kidney and urinary tract (CAKUT) and gene mutations: an analysis of 66 patients at a single institution

BACKGROUND

The association between the clinical presentation of congenital anomalies of the kidney and urinary tract (CAKUT) and gene mutations has yet to be fully explored.

METHODS

In this retrospective cohort study, we examined patients with CAKUT who underwent gene analysis. The analysis was performed in patients with bilateral renal lesions, extrarenal complications, or a family history of renal disease. The data from the diagnosis, gene mutations, and other complications were analyzed.

RESULTS

In total, 66 patients with CAKUT were included. Of these, gene mutations were detected in 14 patients. Bilateral renal lesions were significantly related to the identification of gene mutations (p = 0.02), and no gene mutations were observed in patients with lower urinary tract obstruction (six patients). There was no significant difference in the rate of gene mutations between those with or without extrarenal complications (p = 0.76). The HNF1β gene mutation was identified in most of the patients with hypodysplastic kidney with multicystic dysplastic kidney (six of seven patients). There was no significant difference in the presence or absence of gene mutations with respect to the renal survival rate (log-rank test p = 0.53). The renal prognosis varied, but the differences were not statistically significant for any of the gene mutations.

CONCLUSIONS

CAKUT with bilateral renal lesions were significantly related to gene mutations. We recommend that CAKUT-related gene analysis be considered in cases of bilateral renal lesions. No gene mutations were observed in patients with lower urinary tract obstruction. The renal prognosis varied for each gene mutation.

Mesenchymal stem cell therapy inhibited inflammatory and profibrotic pathways induced by partial bladder outlet obstruction and prevented high-pressure urine storage

BACKGROUND

Partial bladder outlet obstruction (pBOO) is characterized by an initial inflammatory response that progresses to smooth muscle hypertrophy and fibrosis. Current treatment modalities carry high risk of morbidity. Mesenchymal stem cells (MSCs) are undifferentiated adult cells with reparative, immunomodulatory, and anti-inflammatory capacities. The ability of MSCs to inhibit inflammatory and profibrotic pathways in bladder cells has been recently reported.

OBJECTIVES

This study aimed to investigate the therapeutic effects of MSCs on pBOO-induced inflammatory, profibrotic signaling pathways and end-organ physiology.

MATERIALS AND METHODS

Twenty Sprague Dawley rats were randomly assigned to 5 groups: unobstructed controls, pBOO for 2 and 4 weeks, pBOO+MSCs for 2 and 4 weeks. Partial bladder outlet obstruction was surgically induced followed by intravenous injection of MSCs. Endpoint urodynamics was performed, and bladder tissue harvested for analysis. Reverse transcription real time polymerase chain reaction (RT-PCR) and immunohistochemistry were performed to study gene and protein expression of major inflammatory and profibrotic markers.

RESULTS

Partial bladder outlet obstruction resulted in an upregulation of transforming growth factor beta (TGFβ1), mothers against decapentaplegic homolog 2/3 (SMAD2/3), hypoxia inducible factor 1 alpha (HIF1α), hypoxia inducible factor 3 alpha (HIF3α), vascular endothelial growth factor (VEGF), tumor necrosis factor (TNFα), mechanistic target of rapamycin (mTOR), p70 ribosomal S6 protein kinase (p70 S6K), collagen 1 (COL1), and collagen 3 (COL3) expression in a time-dependent manner. This was coupled with a downregulation of interleukin (IL)-10 expression. Increase of bladder fibrosis was directly related to the duration of pBOO and associated with high urine storage pressure. Injected MSCs were identified in the bladder 4 weeks after therapy. The immunomodulatory effect of MSCs(defined by reduced TNFα and increased IL-10 and VEGF) was most predominant 2 weeks after therapy. Significant downregulation of profibrotic genes occurred 4 weeks after therapy. End filling pressure, hypertrophy, and fibrosis were significantly reduced after MSC therapy (P < 0.05).

DISCUSSION

Mesenchymal stem cell therapy led to a profound systematic improvement of the obstructed bladder. This included an initial anti-inflammatory response and a subsequent antifibrotic reaction. Essentially, both phases were associated with a reduction of urine storage pressure. The intravenously injected MSCs were tracked in the bladder. However, their presence in non-target organs such as the lungs, spleen, and liver was not tracked.

CONCLUSIONS

Partial bladder outlet obstruction induced significant upregulation of hypoxic, inflammatory, and profibrotic markers. Mesenchymal stem cell therapy potently inhibited these pathways and improved bladder function.

Developmental pathology of congenital kidney and urinary tract anomalies

Congenital anomalies of the kidneys or lower urinary tract (CAKUT) are the most common causes of renal failure in children and account for 25% of end-stage renal disease in adults. The spectrum of anomalies includes renal agenesis; hypoplasia; dysplasia; supernumerary, ectopic or fused kidneys; duplication; ureteropelvic junction obstruction; primary megaureter or ureterovesical junction obstruction; vesicoureteral reflux; ureterocele; and posterior urethral valves. CAKUT originates from developmental defects and can occur in isolation or as part of other syndromes. In recent decades, along with better understanding of the pathological features of the human congenital urinary tract defects, researchers using animal models have provided valuable insights into the pathogenesis of these diseases. However, the genetic causes and etiology of many CAKUT cases remain unknown, presenting challenges in finding effective treatment. Here we provide an overview of the critical steps of normal development of the urinary system, followed by a description of the pathological features of major types of CAKUT with respect to developmental mechanisms of their etiology.

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

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

The changes of urethral morphology recognized in voiding cystourethrography after endoscopic transurethral incision for posterior urethral valve in boys with intractable daytime urinary incontinence and nocturnal enuresis

PURPOSE

Endoscopic transurethral incision (TUI) of posterior urethral valve (PUV) can improve daytime urinary incontinence (DUI) and nocturnal enuresis (NE). However, the underlying mechanism has not been elucidated. In this study, we retrospectively examined the mobility of the urethra before and after TUI by measuring the urethral angle with voiding cystourethrography (VCUG), to clarify the effects of TUI on the morphology of the urethra during voiding.

METHODS

Between July 2010 and December 2014, 29 boys with intractable DUI and/or NE were diagnosed as PUV and underwent endoscopic TUI. VCUG during voiding phase was performed at sequential radiographic spot images (1 image per second) at a 45° angle in oblique standing position. The point at which the angle of the urethra was the smallest during urination was regarded as the minimum urethral angle. The maximum urethral angle during early voiding phase was compared with the minimum urethral angle, and the percentage by which this angle changed was calculated as the flexion rate. Then changes in minimum urethral angle and flexion rate were analyzed before and 3-4 months after TUI.

RESULTS

After TUI, the minimum urethral angle on VCUG became more obtuse (before vs. after TUI, respectively: 112.7 vs. 124.5°, p < 0.001), the flexion rate decreased (before vs. after TUI, respectively: 11.8 vs. 4.1%, p < 0.001).

CONCLUSIONS

This study demonstrated a significant difference in the degree of change. The findings may contribute to understanding of the mechanism of improvement in symptoms after TUI in patients with PUV.

Postnatal Evaluation and Outcome of Prenatal Hydronephrosis

BACKGROUND

Prenatal hydronephrosis (PNH) is dilation in urinary collecting system and is the most frequent neonatal urinary tract abnormality with an incidence of 1% to 5% of all pregnancies. PNH is defined as anteroposterior diameter (APD) of renal pelvis ≥ 4 mm at gestational age (GA) of < 33 weeks and APD ≥ 7 mm at GA of ≥ 33 weeks to 2 months after birth. All patients need to be evaluated after birth by postnatal renal ultrasonography (US). In the vast majority of cases, watchful waiting is the only thing to do; others need medical or surgical therapy.

OBJECTIVES

There is a direct relationship between APD of renal pelvis and outcome of PNH. Therefore we were to find the best cutoff point APD of renal pelvis which leads to surgical outcome.

PATIENTS AND METHODS

In this retrospective cohort study we followed 200 patients 1 to 60 days old with diagnosis of PNH based on before or after birth ultrasonography; as a prenatal or postnatal detected, respectively. These patients were referred to the nephrology clinic in Zahedan Iran during 2011 to 2013. The first step of investigation was a postnatal renal US, by the same expert radiologist and classifying the patients into 3 groups; normal, mild/moderate and severe. The second step was to perform voiding cystourethrogram (VCUG) for mild/moderate to severe cases at 4 - 6 weeks of life. Tc-diethylene triamine-pentaacetic acid (DTPA) was the last step and for those with normal VCUG who did not show improvement in follow-up examination, US to evaluate obstruction and renal function. Finally all patients with mild/moderate to severe PNH received conservative therapy and surgery was preserved only for progressive cases, obstruction or renal function ≤35%. All patients' data and radiologic information was recorded in separate data forms, and then analyzed by SPSS (version 22).

RESULTS

200 screened PNH patients with male to female ratio 3.5:1 underwent first postnatal control US, of whom 65% had normal, 18% mild/moderate and 17% severe hydronephrosis. 167 patients had VCUG of whom 20.82% with VUR. 112 patients performed DTPA with following results: 50 patients had obstruction and 62 patients showed no obstructive finding. Finally 54% of 200 patients recovered by conservative therapy, 12.5% by surgery and remaining improved without any surgical intervention.

CONCLUSIONS

The best cutoff point of anteroposterior renal pelvis diameter that led to surgery was 15 mm, with sensitivity 88% and specificity 74%.

Rare copy number variants implicated in posterior urethral valves

The cause of posterior urethral valves (PUV) is unknown, but genetic factors are suspected given their familial occurrence. We examined cases of isolated PUV to identify novel copy number variants (CNVs). We identified 56 cases of isolated PUV from all live-births in New York State (1998-2005). Samples were genotyped using Illumina HumanOmni2.5 microarrays. Autosomal and sex-linked CNVs were identified using PennCNV and cnvPartition software. CNVs were prioritized for follow-up if they were absent from in-house controls, contained ≥ 10 consecutive probes, were ≥ 20 Kb in size, had ≤ 20% overlap with variants detected in other birth defect phenotypes screened in our lab, and were rare in population reference controls. We identified 47 rare candidate PUV-associated CNVs in 32 cases; one case had a 3.9 Mb deletion encompassing BMP7. Mutations in BMP7 have been associated with severe anomalies in the mouse urethra. Other interesting CNVs, each detected in a single PUV case included: a deletion of PIK3R3 and TSPAN1, duplication/triplication in FGF12, duplication of FAT1--a gene essential for normal growth and development, a large deletion (>2 Mb) on chromosome 17q that involves TBX2 and TBX4, and large duplications (>1 Mb) on chromosomes 3q and 6q. Our finding of previously unreported novel CNVs in PUV suggests that genetic factors may play a larger role than previously understood. Our data show a potential role of CNVs in up to 57% of cases examined. Investigation of genes in these CNVs may provide further insights into genetic variants that contribute to PUV.

Nadir creatinine in posterior urethral valves: How high is low enough?

INTRODUCTION

Large retrospective studies of people with posterior urethral valves (PUV) have reported chronic renal insufficiency (CRI) in up to one third of the participants and end-stage renal failure in up to one quarter of them. Nadir creatinine (lowest creatinine during the first year following diagnosis) is the recognised prognostic indicator for renal outcome in PUV, the most commonly used cut-off being 1 mg/dl (88.4 umol/l).

OBJECTIVE

To conduct a statistical analysis of nadir creatinine in PUV patients in order to identify the optimal cut-off level as a prognostic indicator for CRI.

STUDY DESIGN

Patients treated by endoscopic valve ablation at the present institution between 1993 and 2004 were reviewed. Chronic renal insufficiency was defined as CKD2 or higher. Statistical methods included receiver operating characteristic (ROC) curve analysis, Fisher exact test and diagnostic utility tests. Statistical significance was defined as P < 0.05.

RESULTS AND DISCUSSION

Nadir creatinine was identified in 96 patients. The median follow-up was 9.4 (IQR 7.0, 13.4) years. A total of 29 (30.2%) patients developed CRI, with nine (9.4%) reaching end-stage renal failure. On ROC analysis, Nadir creatinine was highly prognostic for future CRI, with an Area Under the Curve of 0.887 (P < 0.001). Renal insufficiency occurred in all 10 (100%) patients with nadir creatinine >88.4 umol/l compared with 19 of 86 (22.2%) patients with lower nadir creatinine (P < 0.001). As a test for future CRI, a nadir creatinine cut-off of 88.4 umol/l gave a specificity of 100%, but poor sensitivity of 34.5%. Lowering the cut-off to 75 umol/l resulted in improvement in all diagnostic utility tests (Table). All 14 (100%) patients with nadir creatinine >75 umol/l developed CRI, compared with 15 of 82 (18.3%) patients with lower nadir creatinine (P < 0.001). Sensitivity only approached 95% at 35 umol/l, at which level specificity was low (Table). Two out of 36 (5.6%) patients with nadir creatinine <35 umol/l developed CRI. Multivariate analysis found recurrent UTI (OR 4.733; CI 1.297-17.280) and nadir creatinine >75 umol/l (OR 48.988; CI 4.9-490.11) to be independent risk factors for progression to CRI. Using cut-off values of 35 umol/l and 75 umol/l, patients can be stratified into low-, intermediate- and high-risk groups, with development of CRI in 5.3%, 28.3% and 100%, respectively (P <0.001). The stage of CKD was higher in higher risk groups.

CONCLUSION

Patients with nadir creatinine >75 umol/l (0.85 mg/dl) should be considered at high risk for CRI, while patients with nadir creatinine ≤35 umol/l (0.4 mg/dl) should be considered low risk. Patients with nadir creatinine between these two values have an intermediate risk of CRI.

Long-term follow-up after transurethral treatment of infravesical obstruction in boys

OBJECTIVE

To study whether boys who underwent transurethral treatment of (mild) infravesical obstruction during childhood have lower urinary tract symptoms and complications at young adult age.

MATERIALS AND METHODS

Young adult men who underwent transurethral treatment for infravesical obstruction as a child were contacted. The following measurements were done: International Prostate Symptom Score (IPSS), International Consultation on Incontinence Modular Questionnaire on Urinary Incontinence, frequency volume chart uroflowmetry, and postvoid residual. A group of 151 male students who completed IPSS and underwent uroflowmetry was used as reference group to compare with patients.

RESULTS

Of 135 traceable patients, 87 men (median age 21.9 years; interquartile range [IQR] 19.6-25.6) returned the questionnaires, and 71 underwent uroflowmetry. Median age at initial treatment was 7.9 years (IQR 1.0-10.8). Compared with men in the reference group, patients had similar IPSS and quality of life scores; median IPSS was 3, and IPSS-quality of life 1 (IQR 0.0-1.0). Urgency incontinence and postmicturition incontinence were reported in 2.4% and 8.5%, respectively. Frequency volume charts (n = 29) showed normal frequency and voided volumes. Uroflowmetry results were comparable with the reference group, although 16 (22.5%) patients voided volumes >600 mL. One patient had urethral stricturing, and one a significant postvoid residual.

CONCLUSION

Young adult men treated for (mild) urethral obstruction in childhood have few micturition symptoms and good uroflowmetry results, not different from a reference group. Some patients, however, report incontinence, and this group deserves close attention. Late complications were rare.

The impact of posterior urethral valves on adult quality of life

OBJECTIVE

To investigate the quality of life of men who had been treated for posterior urethral valves (PUV) in childhood.

PATIENTS AND METHODS

Questionnaires were mailed to 108 patients with PUV treated at the Children's Hospital, University of Helsinki, and 67 (62%) of them responded. Three different questionnaires (15D, LSS, and RAND) were used to evaluate the quality of life.

RESULTS

The total quality of life in PUV patients was reported as good compared to the general population in the RAND and LSS surveys. However, in the 15D analysis the PUV patients reported lower scores in sleeping, eating, and sexual activity. Those PUV patients who had been treated for renal insufficiency reported lower scores in several dimensions in all three surveys. Patients with urinary incontinence reported more sleeping problems and regarded themselves physically more disabled.

CONCLUSIONS

The PUV patients with renal insufficiency or urinary incontinence had impaired quality of life in several dimensions.

Urinary infections in children

Urinary tract infection (UTI) is a common infection in infants and children. During infancy, boys are more commonly affected than girls and thereafter, female preponderance is found. Presentation varies among different age groups. Clinical features in neonates and young infants are non-specific, manifest as septicemia where a high index of suspicion is needed. Older children typically present as simple or complicated UTI. Rapid diagnosis, institution of early treatment and further evaluation by imaging modalities are of utmost importance. The prevention of recurrent UTI and detection of congenital anomalies of kidney and urinary tract are major objectives in the management. Use of ultrasound is required to detect underlying congenital abnormalities, whereas voiding cystourethrogram and dimercaptosuccinic acid (DMSA) scan are useful in the diagnosis of obstructive uropathy and vesicoureteric reflux and renal scar, respectively. The children requiring surgical interventions are to be recognised early to prevent recurrent UTI. The treatment of vesicoureteric reflux by chemoprophylaxis in lower grades and surgical treatment in higher grades are important consideration in prevention of recurrent UTI. This is required to prevent renal parenchymal damage and scarring that can cause hypertension and progressive renal insufficiency in later life.

Revised guidelines on management of antenatal hydronephrosis

Widespread antenatal screening has resulted in increased detection of anomalies of the kidneys and urinary tract. The present guidelines update the recommendations published in 2000. Antenatal hydronephrosis (ANH) is transient and resolves by the third trimester in almost one-half cases. The presence of oligohydramnios and additional renal or extrarenal anomalies suggests significant pathology. All patients with ANH should undergo postnatal ultrasonography; the intensity of subsequent evaluation depends on anteroposterior diameter (APD) of the renal pelvis and/or Society for Fetal Urology (SFU) grading. Patients with postnatal APD exceeding 10 mm and/or SFU grade 3-4 should be screened for upper or lower urinary tract obstruction and vesicoureteric reflux (VUR). Infants with VUR should receive antibiotic prophylaxis through the first year of life, and their parents counseled regarding the risk of urinary tract infections. The management of patients with pelviureteric junction or vesicoureteric junction obstruction depends on clinical features and results of sequential ultrasonography and radionuclide renography. Surgery is considered in patients with increasing renal pelvic APD and/or an obstructed renogram with differential renal function <35-40% or its subsequent decline. Further studies are necessary to clarify the role of prenatal intervention, frequency of follow-up investigations and indications for surgery in these patients.

Early outcome following diathermy versus cold knife ablation of posterior urethral valves

OBJECTIVE

To compare early outcomes following diathermy versus cold knife ablation of posterior urethral valves (PUV).

METHODS

All neonates and children who underwent primary ablation of PUV between January 2004 and March 2011 were included. Primary ablation was performed using an 8.5 resectoscope, with either diathermy hook (Group I) or sickle-shaped cold knife (Group II). A uniform management protocol was used and voiding cystourethrogram was repeated in all patients at 3 months follow-up. All patients with poor anterior urethral stream and persistent dilatation of posterior urethra on follow-up underwent repeat cystoscopy. Early outcomes were compared between Groups I and II using Fisher's exact test.

RESULTS

During the study period, a total of 83 cases underwent primary PUV ablation. Group I included 42 patients (mean age 6.2 months; 10 days to 9 years) while Group II included 41 (mean age 3.4 months; 12 days to 5 years). Overall 12/83 (14.4%) required repeat procedure for persistent obstruction: stricture 9 (10.8%); residual valve 3 (3.6%). Group I had a significantly higher stricture rate (9/42; 21.4%) than Group II (0/41) (p = 0.02). There was no significant difference in terms of residual valves, haematuria, retention or extravasation between groups.

CONCLUSION

Cold knife ablation is superior to diathermy in relieving PUV obstruction in a single attempt.

Risk factors for renal insufficiency in children with urethral valves

Posterior urethral valves (PUV) associated with renal dysplasia are one of the most common causes of end stage kidney disease (ESKD) in childhood. In order to identify risk factors for the progression of this condition to early renal failure, we have retrospectively analyzed the clinical course, renal function, and first postnatal renal ultrasound in a sample of 42 young male patients with PUV, who were followed at a single center. Twelve (28.6%) were diagnosed with ESKD at a median age of 11.3 years. Our comparison of PUV patients without decreased estimated glomerular filtration rate (eGFR) (group A; K/DOQI CKD stage 0-1) with PUV patients showing a decreased eGFR (group B; K/DOQI CKD stage 2-5) revealed the following significant risk factors for loss of eGFR: renal volume <3rd percentile (P < 0.001), elevated echogenicity (P = 0.001), pathologic corticomedullary differentiation (P < 0.001), >3 febrile urinary tract infections (P = 0.012), and decreased eGFR at 1 year of age (P < 0.001). Receiver operating characteristic curve analysis in the cohort confirms that patients showing a renal volume >88.2 ml/m(2) body surface area (BSA) are not at risk to develop K/DOQI CKD stage 5 (sensitivity 75%, specificity 77.3%, positive/negative predictive value 37.5/94.4%). Ultrasound promises to be a valuable tool for identifying endangered patients.

Timing of posterior urethral valve diagnosis and its impact on clinical outcome

OBJECTIVE

Our goals were to assess long-term outcome for patients with posterior urethral valves (PUV) and determine the impact of the timing of diagnosis.

PATIENTS AND METHODS

We reviewed the hospital records for patients with PUV treated in 1994-2008. Only those patients diagnosed, treated surgically, and followed clinically at our center were included.

RESULTS

There were 52 patients with PUV. Thirty-nine were diagnosed by 1 year of age (early diagnosis cohort), while 13 were diagnosed after 1 year (late diagnosis cohort). Mean follow up after valve operation was 7.2 years (range 15 months-14 years). Chronic renal failure rates were not statistically different between the early and late diagnosis groups after surgical intervention: 48% (14/29) vs 25% (3/12), P = 0.30. Among the early diagnosis cases, 10% (3/29) eventually required renal transplant, while no child in the late diagnosis group has developed end-stage renal disease to date (P = 0.55).

CONCLUSIONS

Gestational age at diagnosis is an important predictor of postnatal renal outcome. Our results suggest that diagnosis after 1 year of age is associated with a lower risk of developing renal insufficiency on long-term follow up.

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

PURPOSE

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

MATERIALS AND METHODS

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

RESULTS

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

CONCLUSIONS

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

Surgical complications of posterior urethral valve ablation: 20 years experience

PURPOSE

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

MATERIALS AND METHODS

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

RESULTS

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

CONCLUSIONS

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

Cleft palate, arachnoid cyst and posterior urethral valve

A 5-month-old infant presented with cleft palate, febrile urinary tract infection and abnormal movements. His urinary stream was poor and investigations revealed posterior urethral valve and grade V vesicoureteric reflux. This baby was investigated for seizure activity and on MRI of the brain was found to have a large arachnoid cyst, splaying the occipital horns and compressing the posterior aspect of third ventricle leading to dilatation of the ventricles. This seems to be a very unusual coexistence of three abnormalities in one patient for which no plausible explanation can be given. It appears to be a chance finding.

Obstructive renal injury: from fluid mechanics to molecular cell biology

Urinary tract obstruction is a frequent cause of renal impairment. The physiopathology of obstructive nephropathy has long been viewed as a mere mechanical problem. However, recent advances in cell and systems biology have disclosed a complex physiopathology involving a high number of molecular mediators of injury that lead to cellular processes of apoptotic cell death, cell injury leading to inflammation and resultant fibrosis. Functional studies in animal models of ureteral obstruction using a variety of techniques that include genetically modified animals have disclosed an important role for the renin-angiotensin system, transforming growth factor-β1 (TGF-β1) and other mediators of inflammation in this process. In addition, high throughput techniques such as proteomics and transcriptomics have identified potential biomarkers that may guide clinical decision-making.

Abnormal antenatal sonogram: an indicator of disease severity in children with posterior urethral valves

PURPOSE

To review the association of an abnormal prenatal sonogram with most recent serum creatinine in patients with proven posterior urethral valves (PUV).

METHODS

Since 1992, all live-born patients between 1992-2004 with clinically proven PUV, with postnatally proven PUV, from 2 pediatric tertiary care centers, were reviewed for age at diagnosis, most recent serum creatinine, presence of chronic renal failure (CRF) (serum creatinine >2 standard deviations above normal for age), or end stage renal disease (dialysis or transplant). Available antenatal reports from the 2 centres and surrounding community hospitals were reviewed for gestational age (GA) at the time of ultrasound, volume of amniotic fluid, and urinary-tract abnormality.

RESULTS

Thirty-four patients with proven PUV and prenatal sonograms were identified (1992-2004). Eighteen patients had abnormalities on their prenatal sonogram, with poor outcome in 5 (mean follow-up, 8 years [1-13 y]). No specific features were identified on prenatal sonogram. Sixteen patients had normal prenatal sonograms, with poor outcomes in 2 (mean follow-up, 8 years [3-13y]). There is an increased risk of an abnormal serum creatinine among those patients with an abnormal prenatal study, odds ratio (OR) 2.6 (95% confidence interval, 0.35-32).

CONCLUSIONS

PUV represents a spectrum of disease severity. A normal prenatal ultrasound does not preclude PUV. The majority of patients with a normal prenatal examination have good outcomes. The OR suggests that there may be increased risk for poor outcome in those with an abnormal prenatal examination. A multicenter study is necessary to obtain a larger sample size and more precise ORs.

Detrusor glycogen reflects the functional history of bladders with partial outlet obstruction

OBJECTIVE

To assess the relationship between glycogen content in bladder detrusor tissue and historical bladder function in a guinea-pig model of partial bladder outlet obstruction (PBOO).

MATERIALS AND METHODS

In male immature guinea pigs PBOO was created with a silver ring around the proximal urethra; a control group had a sham operation for comparison. Longitudinal individual urodynamic data were obtained weekly, so that guinea pigs were killed at different levels of bladder dysfunction. Bladder sections were stained with periodic acid-Schiff (PAS) to assess overall morphology and glycogen granule density, scored from 0 (no glycogen) to 3. Glycogen scores were related to both the end-stage and historical extremes of bladder function values.

RESULTS

Glycogen granules were seen only in the detrusor; as their number increased their location expanded from only close to the serosa (glycogen score 1), through the detrusor (score 2) up to the urothelium (score 3). A glycogen score of 0 correlated with normal values for all urodynamic variables. Compared with a glycogen score of 0 a score of 1 correlated with significant (P < 0.05) changes in end-stage compliance (decrease) and contractility (increase) and significantly higher historical values for contractility, pressure and number of unstable contractions (NUC). In the group with a glycogen score of 2 there were significant changes in both the end-stage values and historical extremes for compliance, pressure, contractility and NUC (all P < 0.05). In the group with a glycogen score of 3 all these changes were even more dramatic, except for the end-stage contractility, for which the increase was not significant. From glycogen score 0 to score 3 all changes increased in magnitude.

CONCLUSION

A high glycogen content reflects a history of abnormal urodynamic function. This finding exemplifies the added value of structural analysis to urodynamic studies. Further studies are needed to relate bladder structure to the potential for functional recovery.

Posterior urethral valve: Outcome of antenatal intervention

INTRODUCTION AND AIM

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

Obstructive uropathy

Routine second trimester ultrasound screening has resulted in more infants diagnosed with antenatal hydronephrosis. Current recommendations suggest postnatal evaluation of all infants with a renal pelvic diameter >5 mm with ultrasound and voiding cystourethrogram (VCUG.) There are many etiologies of obstructive uropathy including ureteropelvic junction (UPJ) obstruction, ureterovesical junction (UVJ) obstruction, posterior urethral valves (PUV), prune belly syndrome, and vesicoureteral reflux (VUR). Obstructive uropathy can result in tubular damage and decreased nephron number. Tubular damage can result in sodium wasting, hyperkalemic acidosis, and nephrogenic diabetes insipidus. Most patients do not require renal replacement therapy in the neonatal period; however, chronic renal insufficiency can occur if the neonate has a significant reduction in nephron number or progressive renal damage from obstruction or infection.

Posterior Urethral Valves: Prenatal Diagnostic Signs and Outcome

INTRODUCTION

Urethral valves can be of enormous clinical importance. Both the prognosis for an affected fetus and the indication for a prenatal therapeutic intervention depend to a high degree on the accuracy of the prenatal diagnosis.

PATIENTS AND METHODS

The sonographic findings and the results of the postnatal diagnostic workup of 24 boys treated for urethral valves in our institute are analyzed in the present paper.

RESULTS

Out of a group of 900 children, diagnosed prenatally as having urinary tract anomalies, the postnatal diagnostic workup revealed 24 boys suffering from posterior urethral valves. The combination of megacystis, oligohydramnios, and bilateral renal abnormalities was present in 3 boys, and it was only in these cases that urethral valves were correctly identified as the underlying pathology. The largest group (n = 16) of these fetuses presented with bilateral hydronephrosis with and without megaureter. Megacystis in any combination with other findings was detected only in 4 patients. Oligohydramnios as a sign of impaired renal function was observed in four pregnancies. Four children suffered postnatally from beginning renal insufficiency. Eight infants (33%) required some form of respiratory support. This group included the 4 newborns with oligohydramnios during the pregnancy.

CONCLUSIONS

Posterior urethral valves represent a rare but severe congenital malformation. They can disrupt the development of the entire urinary tract and may be life-limiting to the affected boy. Only rarely, however, are they manifested as the complete pathological picture on prenatal ultrasound. In most cases, bilateral impairment of the fetal renal development suggests severe subvesical obstruction. Thus in cases with bilateral renal impairment on prenatal ultrasonography, posterior urethral valves are to be excluded postnatally. Oligohydramnios is a predictor of a poor outcome of the renal function.