The Impact of Late Presentation of Posterior Urethral Valves on Bladder and Renal Function

Congenital anomalies of the kidney and urinary tract: defining risk factors of disease progression and determinants of outcomes

Congenital anomalies of the kidney and urinary tract (CAKUT) result from disruptions in normal kidney and urinary tract development during fetal life and collectively represent the most common cause of kidney failure in children worldwide. The antenatal determinants of CAKUT are diverse and include mutations in genes responsible for normal nephrogenesis, alterations in maternal and fetal environments, and obstruction within the normal developing urinary tract. The resultant clinical phenotypes are complex and depend on the timing of the insult, the penetrance of underlying gene mutations, and the severity and timing of obstruction related to the sequence of normal kidney development. Consequently, there is a broad spectrum of outcomes for children born with CAKUT. In this review, we explore the most common forms of CAKUT and those most likely to develop long-term complications of their associated kidney malformations. We discuss the relevant outcomes for the different forms of CAKUT and what is known about clinical characteristics across the CAKUT spectrum that are risk factors of long-term kidney injury and disease progression.

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

OBJECTIVE

To determine the adulthood outcomes of bladder, kidney, and sexual functions of posterior urethral valve (PUV) patients.

MATERIALS AND METHODS

The records of patients who were treated for PUV between 1980, and 2001 and aged ≥18 years by the end of 2019 were retrospectively reviewed. Patients with complete adulthood data were included in the study. Renal, bladder, and sexual functions were assessed. Adulthood uroflowmetry results of 22 patients were also evaluated.

RESULTS

Thirty-nine patients with complete adulthood data out of 89 were included. The median follow-up time was 22.7 years (15-33 years). Median age at initial surgery for PUV was 36 months (1-168 months), and median age at last follow-up was 26 years (18-46 years). Lower urinary tract dysfunction was noted in 15 (38%) patients. In 22 patients (56%) with uroflowmetric analyses, median values of Q_max, voided volume, and post voiding residual urine volume were 20.5 mL/sec (7-43 mL/sec), 389 mL (154-1750 mL), and 18.5 mL (range 0-190 mL), respectively. Nineteen patients (48.7%) had normal glomerular filtration rate, 2 patients (5.1%) had chronic kidney disease, and the remaining 18 patients (46.1%) had end stage renal disease, 14 (35.9%) of whom underwent renal transplantation. Thirty-two patients (82%) had sexual function evaluation, none of which reported erectile dysfunction. However, 4 patients (12.5%) reported slow ejaculation. Five patients fathered a child whereas infertility was observed in 2 patients.

CONCLUSION

After 2 decades, glomerular filtration rate was normal almost in half of the PUV patients while lower urinary tract dysfunction was detected in 38%. Furthermore, erectile dysfunction was rare.

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.

An Unusual Urological Manifestation of Williams-Beuren Syndrome: Posterior Urethral Valve

Williams-Beuren syndrome (WBS) is a genetic, well-defined, rare, neurodevelopmental disorder characterized by intellectual disability, congenital heart defects, abnormal facial features, and growth, endocrine, and genitourinary abnormalities. The genitourinary abnormalities in WBS frequently include congenital structural renal defects, vesicoureteral reflux, nephrocalcinosis, proteinuria, and chronic renal insufficiency. Treatment of patients with posterior urethral valve (PUV) remains a clinical challenge, requiring long-term management from early infancy into adulthood in order to avoid progressive renal insufficiency. To my knowledge, this is the first worldwide case of WBS with PUV in a 12-year-old boy. Due to the delayed detection of the defect, chronic renal disease occurred as a risk for him. This case demonstrates the importance of early diagnosis of genitourinary anomalies such as PUV to prevent chronic renal disease in boys and especially in patients with WBS.

Predicting and Modifying Risk for Development of Renal Failure in Boys with Posterior Urethral Valves

PURPOSE OF REVIEW

The purpose of this review is to bring the reader up to date on the current risk factors for the development of renal deterioration in the boys with posterior urethral valves (PUV) and approaches to modify this risk.

RECENT FINDINGS

Renal bladder ultrasound (RBUS) is routinely performed in boys with PUV and recent advancements allow imaging processing that can more accurately quantify renal parenchyma and correlate this with risk for renal loss. Refinement of urine studies may improve our ability to stratify patients into renal loss categories. Use of videourodynamics (VUDS) allows refined assessment of the valve bladder to identify those who might benefit from secondary procedures and/or the addition of targeted pharmacotherapy to improve bladder emptying or dangerous storage pressures. All boys with a history of PUV are at a significant long-term risk of renal deterioration. The literature suggests that several technical advances have improved our ability to predict this risk, although there needs to be further refinement and validation before widespread use. Utilization of close follow-up, VUDS, pharmacotherapy, and bladder drainage provide the best methods to improve care to this group of patients and if more studies confirm their utility, adoption of these as part of standard of care protocols may be warranted.

Late diagnosis of posterior urethral valves

CLINICAL PROBLEM

We diagnosed 8 patients with late-stage posterior urethral valves (PUV) between 1 and 14 years of age. Five patients complained of symptoms related to voiding dysfunction. The other 3 patients required urethrocystoscopy for other reasons (hypospadias fistulae, difficulty with catheterisation and high-grade vesicoureteral reflux [VUR]). A second review of the first 2 patients' medical history showed voiding dysfunction symptoms. All patients underwent preoperative ultrasonography: 3 patients had normal results and 5 had renal or vesical disorders. The diagnosis was reached through voiding cystourethrogram (VCUG), and 4 patients underwent urodynamic studies. The diagnosis was confirmed by urethrocystoscopy, performing valve electrofulguration. We performed urethrocystoscopy during the check-ups at 3-6 weeks and observed no stenosis. The symptoms disappeared for all patients after 20 months of follow-up. The patient with VUR was cured. The ultrasounds showed no progression of the renal involvement and showed improvement in the vesical involvement. The velocimetries during check-ups presented curves within normal ranges.

DISCUSSION

Most children with PUV are diagnosed through ultrasound during the neonatal period. Some patients present PUV at later ages with diverse symptoms, which impedes its diagnosis. We should suspect PUV in male patients with symptoms of voiding dysfunction, either when they have normal or pathological results from ultrasounds or VCUG. We recommend performing urethrocystoscopy to rule out urethral obstruction.

Antenatal Determinants of Long-Term Kidney Outcome in Boys with Posterior Urethral Valves

Background: Posterior urethral valves (PUV) are the most important cause of end-stage renal disease (ESRD) in young boys. The objective of this report was to define the antenatal determinants of long-term postnatal renal outcome in this condition. Design: This was a retrospective cohort analysis. The primary outcome was the development of ESRD defined as starting dialysis or receiving a preemptive kidney transplant. Results: Eighty-two cases of PUV were identified, with 17 (21%) developing ESRD at 6.1 ± 7.1 years. Cases developing ESRD were more likely diagnosed antenatally (41 vs. 19%, p = 0.05), had a younger gestational age (35.5 ± 3.4 weeks vs. 37.3 ± 2.1 weeks, p = 0.02), and on antenatal ultrasound scan were more likely to have oligohydramnios (60 vs. 26%, p = 0.02), renal cortical cysts (47 vs. 17%, p = 0.02), and the combination of oligohydramnios, renal cortical cysts, and increased renal echogenicity (47 vs. 9%, p = 0.002). Conclusions: In boys with PUV, decreased gestational age, oligohydramnios, renal cysts, and the combination of oligohydramnios, cortical cysts, and echogenic kidneys were associated with ESRD, while the combination was an independent predictor of poor long-term postnatal kidney function.

Posterior urethral valve: delayed presentation in adolescence

Posterior urethral valves (PUV) are now commonly suspected on antenatal ultrasound, but can present with a broad spectrum of severity postnatally. Rarely, the diagnosis is missed until adolescence or adulthood when the patient usually presents with lower urinary tract symptoms. We describe an even rarer case of PUV in a late adolescent who first presented with preserved renal function and urinary incontinence. We review the literature on presentation, natural history and outcomes of both early and late presenting PUV cases.

The significance of detrusor wall thickness as a prognostic factor in pediatric bladder outlet obstruction

PURPOSE

The purpose of this study is to determine detrusor thickness as a prognostic factor in posterior urethral valves.

METHODS

The medical information of 41 patients diagnosed with posterior urethral valves at our institute was retrospectively reviewed. The serum creatinine level after bladder decompression, results of ultrasonography, and voiding cystourethrography were compared between groups divided according to the final bladder and renal function. Detrusor thickness was measured using Müller's method.

RESULTS

The median detrusor thickness was 1.3 mm (0.4-2.5 mm). After median 45.6 months (7.2-96.0 months) of follow-up, impaired bladder function (IBF) was observed in 14 patients. In multivariate analysis, detrusor thickness greater than 1.3 mm (odds ratio, 32.6; 95% confidence interval, 3.1-340.6; P = .004) was the only independent risk factor for later IBF. Final renal function impairment developed in 24 patients (58.5%), and 3 patients (7.3%) were diagnosed with end-stage renal disease after median 66.0 months (32.4-133.2 months) of follow-up period. On multivariate analysis, age-specific elevated serum creatinine level at presentation (odds ratio, 11.1; 95% confidence interval, 1.1-112.5; P = .042) was an independent risk factor.

CONCLUSIONS

Detrusor thickness more than 1.3 mm on ultrasonography was an independent prognostic factor for later IBF.

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.

Posterior urethral valves: multivariate analysis of factors affecting the final renal outcome

PURPOSE

Posterior urethral valves represent the most common obstructive uropathy in children with a broad spectrum of clinical severity. We evaluated prognostic variables affecting the outcome of renal function in such children.

MATERIALS AND METHODS

Between 1987 and 2004, 120 patients with a mean age of 2 years with posterior urethral valves were treated initially with valve ablation at our center. We studied certain parameters, including age at presentation, serum creatinine (initial and nadir), initial creatinine clearance, renal ultrasound findings (hydronephrosis and renal parenchymal echogenicity), vesicoureteral reflux on initial voiding cystourethrogram, bladder dysfunction and popoff mechanisms such as the syndrome of large vesical diverticulum, urinoma and ascites. Long-term renal outcome was assessed.

RESULTS

Followup was 2 to 16 years (median 3.6). Renal insufficiency developed at the end of followup in 44 patients (36.5%). Serum creatinine at hospital admission, nadir serum creatinine, initial creatinine clearance and renal parenchymal echogenicity were significant predictors of the final renal outcome (p < 0.05). Patient age at diagnosis (2 or less vs greater than 2 years), upper tract dilatation, the presence or absence of vesicoureteral reflux, popoff mechanisms and bladder dysfunction had no significant impact on future renal function. On multivariate analysis nadir serum creatinine was the only independent prognostic factor.

CONCLUSIONS

Our data confirm the high prognostic value of nadir creatinine after primary valve ablation. Also, initial serum creatinine, creatinine clearance and renal parenchymal echogenicity on initial renal ultrasound correlate significantly with long-term renal function in children with posterior urethral valves.

Risk factors associated with chronic kidney disease in patients with posterior urethral valves without prenatal hydronephrosis

PURPOSE

Postnatal diagnosis of posterior urethral valves continues despite the prevalence of prenatal ultrasound. We identified risk factors associated with chronic kidney disease in these children.

MATERIALS AND METHODS

We retrospectively reviewed the medical records of boys with posterior urethral valves with clinical presentations other than prenatal hydronephrosis. We recorded presenting symptoms, age at presentation, and preoperative hydronephrosis and/or vesicoureteral reflux. Chronic kidney disease was defined as previous renal transplantation, dialysis dependence or glomerular filtration rate less than 60 ml per minute/1.73 m(2) at last followup. We used univariate survival analysis with the log rank test of equality for categorical variables and Cox proportional hazard regression for continuous variables to identify risk factors associated with progression to chronic kidney disease.

RESULTS

We identified 141 boys with posterior urethral valves with a postnatal presentation. Median age at presentation was 46 months (range 0.3 to 174). Febrile urinary tract infection in 28% of patients and voiding complaints in 50% were the most common presentations. A total of 12 patients (9%) progressed to chronic kidney disease up to 23 years after initial presentation. Preoperative bilateral hydronephrosis, increased hydronephrosis severity and bilateral vesicoureteral reflux were associated with progression to chronic kidney disease.

CONCLUSIONS

Approximately 10% of cases with postnatal presentation of posterior urethral valves progress to chronic kidney disease, sometimes decades after the initial presentations. Although all patients with posterior urethral valves should be counseled on the potential loss of renal function, children with risk factors warrant close followup into adulthood.

Lower abdominal mass in a 16-year old adolescent: an unusual presentation of posterior urethral valves

Posterior urethral valves (PUV) are now commonly suspected on antenatal ultrasound, but can present with a broad spectrum of severity postnatally. Rarely, the diagnosis is missed until adolescence or adulthood when the patient usually presents with lower urinary tract symptoms. We describe an even rarer case of PUV in an adolescent who first presented with renal failure and a palpable lower abdominal mass due to urinary retention. We review the literature on presentation, natural history and outcomes of both early and late presenting PUV cases.

CONGENITAL URINARY BLADDER OUTLET OBSTRUCTION

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

Effects of doxycycline on voiding behaviour of rats with bladder outlet obstruction

OBJECTIVE

To examine the voiding behaviour changes in rats with bladder outlet obstruction (BOO) while inhibiting matrix metalloproteinase (MMP) activity with doxycycline, as increased MMP activity may be involved in obstruction-induced bladder hypertrophy.

MATERIALS AND METHODS

Female Sprague-Dawley were divided into eight groups (three rats in each group): normal control (NC) +/- doxycycline, 3 weeks partial BOO (3WPBOO) +/- doxycycline, 6 weeks PBOO +/- doxycycline, and 3 weeks PBOO followed by 3 weeks de-obstruction (3WOD) +/- doxycycline. All rats received the same food and water and were on the same 12 h dark/light cycle housed in metabolic cages. Treatment groups were given doxycycline 15 mg/kg/day subcutaneously twice daily. The voiding variables measured were average voided volume (AV V) and voiding frequency (VF) in 24 h. After completion of the voiding behaviour studies, the rats were killed and their bladders were excised and weighed.

RESULTS

The AV Vs were significantly increased (P < 0.05) in all study groups compared with the NC group except for the 3WPBOO-doxycycline and 3WOD-doxycycline groups. The VF was significantly increased (P < 0.05) only in the 3WOD-doxycycline group. The bladder weights were significantly increased after PBOO in all the study groups (P < 0.05), except for the 3WOD group.

CONCLUSION

These data show that MMP inhibition may affect voiding behaviour during the response to BOO or its relief. This is the first clinical demonstration that interfering with a principal target of bladder muscle wall remodelling may have a direct effect on bladder function.

Clinical and radiological characteristics of Nigerian boys with posterior urethral valves

Posterior urethral valve (PUV) obstruction is the most common cause of bladder outlet obstruction in boys. Currently, the diagnosis of PUV is commonly made prenatally. In our environment, however, prenatal diagnosis is rare and the diagnosis is usually made postnatally from the clinical and radiological features. This study therefore examines the clinical and radiological spectrum of boys with PUV in our environment. We examined the clinical presentations, ultrasonographic and the micturating cystourethrographic (MCUG) features of boys with PUV in our institution over a 22-month period from June 2006. There were 28 patients with PUV over this period. The age at presentation ranged from 11 days to 11 years (mean age = 2.7 years). Although prenatal ultrasound scan was done in 23 (82.1%) patients, no prenatal diagnosis was made in any of the patients. The diagnosis was made after infancy in 16 (57.1%) patients. Recurrent urinary tract infection (UTI) was the most common mode of presentation occurring in 14 (50.0%) patients with 7 (50.0%) of the patients with UTI presenting with septicaemia. Voiding dysfunctions, which occurred in all the patients, were the primary mode of presentation in 12 (42.9%) patients. Three (10.7%) patients presented with renal insufficiency, which was significantly associated with the age at presentation (P = 0.026). Ultrasound scan done in the postnatal period strongly suggested the diagnosis of posterior urethral valves in 22 (78.6%) patients in whom the posterior urethra was found to be dilated, associated with thick-walled urinary bladder and bilateral hydronephrosis. Trabeculations of the bladder was a constant feature on MCUG. Other features on MCUG included dilatation of the posterior urethra in 26 (92.8%), bladder diverticuli in 15 (53.6%) and unilateral and bilateral vesicoureteric reflux in 3 (10.7%) and 1 (3.6%) patient(s), respectively. The diagnosis of PUV obstruction which is often made late in our environment, is mainly by clinical, sonographic and MCUG features in the postnatal period. A majority of patients present late, with recurrent UTI.

Imaging in childhood urinary tract infections: time to reduce investigations

The correct protocol for investigating urinary tract infections (UTI) is unknown but remains a hotly debated topic. The main objective in investigating children with UTI is to prevent the long-term complications of developing hypertension, chronic kidney disease (CKD) and/or pregnancy complications. However, the prognosis for childhood UTI remains good, with low long-term risks, from epidemiological studies, of developing these sequelae. Although childhood UTI is common, the occurrence of CKD and the likelihood that acute pyelonephritis will cause renal damage progressing to CKD are rare. We studied the current literature on investigations of childhood UTI and propose a protocol for carrying out selected investigations in high-risk children. By identifying this group of children with increased risk of having an abnormal urinary tract that warrant investigation, we recommend that targeting investigations to specific children (as opposed to protocol-based investigations of all children with UTI), will be clinically safe and effective and will avoid the unnecessary distress and cost of invasive investigations.

Current diagnosis and management of fetal genitourinary abnormalities

Prenatal assessment with ultrasonography provides excellent imaging of fluid-filled structures (eg, hydronephrosis, renal cysts, and dilated bladder) and renal parenchyma. This information allows for the generation of a differential diagnosis, identification of associated anomalies, and assessment of the prenatal and postnatal risks of a given anomaly. This enhances parental education and prenatal and postnatal planning. This article discusses the current methods of diagnosis and management of fetal genitourinary anomalies, and also the postnatal evaluation and treatment of these conditions.