Predictors of upper tract damage in pediatric neurogenic bladder

Is Retinol Binding Protein 4 a Good Biomarker of Renal Function in Children with Neurogenic Bladder After Myelomeningocele?

Background: This prospective study aimed to evaluate renal function using retinol binding protein 4 (RBP4), cystatin C, and glomerular filtration rate (GFR) in relation to physical activity and lesion level in children with neurogenic bladder (NB) post-myelomeningocele. Methods: Two groups were studied: 33 children with NB and 20 healthy controls. Data collected included demographic details, physical activity levels, uroflowmetry, urodynamic diagnosis, and renal function parameters. Urinary RBP4 and serum cystatin C were measured using ELISA, and GFR was calculated using the Schwartz formula. Results: The NB group had higher median serum cystatin C and urinary RBP4/creatinine ratios compared to the control group (0.28 vs. 0.22; 18.6 vs. 3.2, respectively). The participants were categorized based on activity levels, lesion levels, catheterization status, and urodynamic diagnosis. No differences in RBP4, cystatin C, or urodynamic diagnosis were observed according to activity and lesion levels. Significant differences in GFR were found based on activity and lesion levels, with higher median GFR in NB children (182.7 vs. 147.3). No differences were found between catheterized and non-catheterized children in the studied parameters. Conclusions: Elevated urinary RBP4 in NB patients suggests possible proximal renal tubule dysfunction. Higher serum cystatin C despite lower creatinine levels indicates altered renal function in NB children. Urinary RBP4 correlates positively with bladder pressure at maximum cystometric capacity, suggesting potential utility in therapy monitoring and modification.

Recent developments in diagnostic ultrasound for lower urinary tract function

Ultrasonography (US) is an essential tool in the clinical management of lower urinary tract dysfunction (LUTD), including lower urinary tract symptoms, overactive bladder, and benign prostatic hyperplasia, in which prostatic volume and post-void residual volume are routinely used to evaluate the pathophysiological characteristics of afflicted patients. US can also be employed to diagnose hydronephrosis and bladder calculus as complications of severe LUTD. Moreover, US is essential for identifying pathophysiological characteristics and surgical indications, predicting disease development and drug efficacy, and monitoring bladder function improvement by means of such parameters as bladder wall thickness, prostatic urethral length, intravesical prostatic protrusion, and prostatic urethral angulation/angle. Herein, I narratively review the recent advances in US approaches for the management of LUTD, especially in adult males.

The urological evaluation and management of neurogenic bladder in children and adolescents-what every pediatric nephrologist needs to know

Neurogenic bladder (NGB) is an encompassing term that includes multiple causes of bladder dysfunction linked to a congenital or acquired neurological condition that adversely impacts the innervation of the lower urinary tract. Multiple static or progressive conditions can be associated with NGB in pediatric and adolescent patients. Currently, spinal dysraphism (i.e., spina bifida) is one of the most common etiologies, which occurs in 3-4 per 10,000 live births in developed nations. Abnormal bladder dynamics can lead to kidney damage secondary to high pressures or recurrent infections, as well as urinary incontinence. The current management paradigm centers on a proactive approach to preserving kidney function and achieving continence through behavioral, pharmacological, and surgical means. This educational review highlights the key components of urological management to maximize collaboration with pediatric nephrologists.

Evaluation of Urinary L-FABP as a Tubular Damage Marker in Pediatric Neurogenic Bladder-A Pilot Study

The article aims to find potential biomarker for the detection of tubular damage in pediatric neurogenic bladder (NB) by investigating urinary levels of liver-type fatty acid-binding protein (uL-FABP). This prospective analysis was conducted on two groups: 42 children with NB and 18 healthy children. The uL-FABP concentrations were measured using ELISA methods. The medical charts of the children were examined to determine age, sex, anthropometric measurements, activity assessment using Hoffer's scale, and renal function parameters. The results revealed that the uL-FABP/creatinine ratio was higher in the study group compared with the reference group, but the difference was not statistically significant (p = 0.52, p > 0.05). However, the uL-FABP/creatinine ratio exhibited a wider range in NB patients compared to the reference group. NB children with proteinuria and the history of high-grade vesicoureteral reflux (VUR) tended to have the highest uL-FABP concentrations. In conclusion, uL-FABP may be considered a potential tubular damage biomarker in children with NB. Proteinuria and the history of VUR may be the factors influencing the uL-FABP.

Application of urodynamics combined with contrast-enhanced ultrasound in evaluation of the urinary tract in patients with low bladder compliance and vesicoureteric reflux who underwent bladder augmentation alone

We assessed the use of common urodynamics (CUD) combined with contrast-enhanced ultrasound (CEUS) to investigate the efficacy and durability of sigmoid cystoplasty alone in patients with low bladder compliance associated with vesicoureteric reflux (VUR). In this study, we recruited 25 patients with low bladder compliance and VUR who underwent bladder augmentation without antireflux surgery at our institutions between June 2017 and June 2021. The bladder condition and VUR grade were assessed preoperatively and postoperatively via CUD combined with CEUS. The mean follow-up period was 2.6 years. CUD showed significant improvement in bladder capacity and compliance and a decrease in intravesical pressure after sigmoid cystoplasty. CEUS demonstrated resolution of VUR compared with preoperative assessment. Of the 25 patients who had various degrees of reflux, VUR was eliminated in 18 patients and reduced to a lower grade in the remaining seven patients. CUD combined with CEUS is accurate and safe. They are invaluable and reliable tools for morphological and functional evaluations of the entire urinary tract in patients with low bladder compliance and VUR.

A Study of Urodynamic Parameters at Different Bladder Filling Stages for Predicting Upper Urinary Tract Dilatation

Purpose

To identify more accurate predictors of upper urinary tract dilatation (UUTD) in neurogenic bladder (NB) children, we studied the relationship among urodynamic parameters at different bladder filling stages, detrusor leak point pressure (DLPP) and UUTD.

Methods

A total of 158 children (3–16 years) with NB were included and then divided into 2 groups according to whether their NB diagnosis was complicated with UUTD: the UUTD group (39 patients) and those without UUTD group (control group, 119 patients). The bladder filling phase was divided into 3 equal parts: the early, middle, and end filling stages. The bladder compliance (BC) and detrusor pressure (△P_det) at each phase and DLPP at the end filling stage were recorded.

Results

A BC<8 mL/cm H₂O both in the middle and end stages is more specific than a BC<9 mL/cm H₂O in the end stage (72%, 73%, vs. 66%), and △P_det >8 cm H₂O in the early stage, 20 cm H₂O in the middle stage and 25 cm H₂O in the end stage are more sensitive than △P_det >40 cm H₂O in the end stage (82%, 85%, 85%, vs. 49%). A DLPP cutoff value of 20 cm H₂O showed higher sensitivity for predicting UUTD than 40 cm H₂O.

Conclusions

Low BC and a high △P_det in the middle and end filling stages are more accurate factors than classic indicators for predicting UUTD. In addition, a DLPP value of >20 cm H₂O in the end bladder filling stage shows high sensitivity.

The safety cutoff storage pressure for preventing upper urinary tract damage in neurogenic bladder from spinal cord pathology and risk factor analysis

INTRODUCTION

Low-compliance bladder or high bladder pressure undoubtedly leads to hydronephrosis and renal impairment. As four decades have elapsed since a previous study found a detrusor leak-point pressure (DLPP) >40 cm H₂ O to result in hydronephrosis, we suspected the possibility of hydronephrosis or vesicoureteral reflux occurring at any point below the 40 cm H₂ O DLPP reference. Therefore, this study aimed to determine the storage detrusor pressure value and risk factors related to upper urinary tract damage (UUTD).

MATERIALS AND METHODS

This study retrospectively reviewed the hospital records of 110 patients who visited the Neurogenic Bladder TU Service of Excellence Unit, Thammasat University Hospital, Pathum Thani, Thailand, and were diagnosed with neurogenic bladder between 2016 and 2020. The inclusion criteria were as follows: patients who were diagnosed with neurogenic bladder from spinal cord problems (spinal dysraphism, spinal cord disease [tumor, degenerative, arteriovenous malformation, etc.], or traumatic spinal cord injury) and underwent a complete examination, including urodynamic study and renal ultrasound. The exclusion criteria were as follows: patients who had previous pelvic irradiation, other concomitant neurological disease (stroke, Parkinson's disease, etc.), or other urological diseases (stone, tumor, etc.), and those who had an indwelling suprapubic or urethral catheter. We identified the cutoff point for storage pressure related to UUTD using receiver operating characteristic (ROC) curve analysis to identify the value that produced maximum sensitivity and specificity. To identify risk factors for developing UUTD, we included seven risk factors: intravesical pressure, poor compliance, detrusor overactivity (DO), detrusor sphincter dyssynergia (DSD), level of the spinal cord pathology, male sex, and spontaneous voiding in univariable and multivariable regression analyses.

RESULTS

Of the 110 patients who met the inclusion criteria, 22 were excluded from the study. Fifty-nine patients had a normal upper urinary tract, and 29 had UUTD. The mean age, sex, voiding pattern, type of spinal cord pathology, and level of spinal cord lesions were not different between the two groups. After performing ROC curve analysis, a cutoff value for daily storage pressure ≥15 cm H₂ O provided 79.31% sensitivity and 67.80% specificity (area under the ROC curve: 0.73) for UUTD development. From univariable analysis, low compliance (cutoff values at <12.5 and <20 ml/cm H₂ O) and a storage pressure ≥15 cm H₂ O was related to UUTD with statistical significance (risk ratio [RR]: 3.16, 2.3, and 3.6, respectively [p < 0.05]). After performing multivariable analysis, a storage pressure ≥15 cm H₂ O and both cutoff values for low compliance were related to UUTD with statistical significance (RR: 3.9, 2.4, and 3.2, respectively [p < 0.05]). However, other factors, including male sex, spontaneous voiding, suprasacral lesion, DSD, and DO, were not related to UUTD.

CONCLUSION

Our results demonstrated that low compliance and a storage pressure ≥15 cm H₂ O were significantly associated with UUTD. Various bladder-management strategies have been developed to prevent UUTDs. However, the main concept continues to be the maintenance of a low storage pressure.

Clinical utility of the maximum area of detrusor tracing measurement in the urodynamic studies in pediatric population diagnosed with neuropathic bladder: A pilot study

INTRODUCTION

Neuropathic bladder (NB) is a lower urinary tract dysfunction (LUTD) that may lead to kidney failure. Urodynamic study is the gold standard for its diagnosis and follow-up. A classic prognostic parameter to predict the risk of upper urinary tract damage (UUTD) is the detrusor leak point pressure (DLPP) ≥  40 cmH2O, although this factor alone may lack prognostic value. The area under the curve (AUC) of the detrusor pressure tracing has been recently described as a prognostic factor.

AIM

To analyze the clinical utility of the AUC of the detrusor pressure tracing in the pediatric population (<15 years).

METHODS

Retrospective study of urodynamic recordings in pediatric population with NB from 2011 to 2020. The following variables were evaluated: detrusor leak point pressure ≥ 40 cmH2O, voiding dysfunction, bladder compliance and overactivity. The sample is classified according to clinical-radiological findings at the time of the UD. AUC is calculated using Newton-Cotes rules (trapezium, Simpson's rule) and its indexes are calculated according to bladder capacity (TI: Trapezium Index, SI: Simpson Index). Statistical significance: P < .05.

RESULTS

Fifty-five recordings are analyzed. Unfavorable clinical condition was identified in 41.8% (n = 23) patients. Voiding dysfunction, low compliance and both indexes were associated with an unfavorable clinical condition (P < .05). ROC analysis showed the following AUC for the new indexes: TI (0.736, P = 0.0006), SI (0.755, P = .0001) with a cut-off value of 10,69 and 8 cmH2O·s/cc, respectively. We did not find differences in the diagnostic performance between them (P > .05).

CONCLUSIONS

The analyzed indexes are useful in the diagnosis of patients with NB and unfavorable clinical condition.

Defining Urinary Tract Infections in Children With Spina Bifida: A Systematic Review

CONTEXT

Children with spina bifida are at high risk for urinary tract infections (UTI). However, there is no standardized definition of UTI in this population, leading to variability in both clinical management and research. This was highlighted in the 2013 systematic review on the same topic.

OBJECTIVE

Evaluate the frequency with which researchers are defining UTI in their studies of children with spina bifida and to determine what parameters are used.

DATA SOURCES

We searched Medline and Scopus databases for articles that included pediatric patients with spina bifida and used UTI as an outcome.

STUDY SELECTION

Exclusion criteria included publication before October 1, 2012, non-English language, and nonprimary research articles.

DATA EXTRACTION

Two independent reviewers each extracted data.

RESULTS

A total of 39 studies were included; 74% of these analyzed included an explicit definition of UTI. The most commonly used definition included a combination of symptoms and culture results (34.5%), whereas 31% used a combination of symptoms, culture results, and urinalysis data. Only 3.4% of articles used a urine culture alone to define UTI.

CONCLUSIONS

More articles that focus on children with spina bifida included a definition of UTI. However, significant variability persists in the definition of UTI in this patient population.

The Importance of Early Diagnosis and Management of Pediatric Neurogenic Bladder Dysfunction

Neurogenic bladder dysfunction is a major source of urologic morbidity in children, especially in those with spina bifida (SB). Complications from progression of bladder dysfunction can include urinary tract infections (UTIs), urinary incontinence, upper tract deterioration, and renal dysfunction or failure. In these children, there has been a recent trend toward proactive rather than expectant management of neurogenic bladder. However, there is a lack of consensus on how to best achieve the three main goals of neurogenic bladder management: 1) preserving kidney function, 2) achieving continence (if desired by the family/individual), and 3) achieving social and functional urologic independence (if appropriate). Hence, our objective was to perform a narrative literature review to evaluate the approaches to diagnosis and management of pediatric neurogenic bladder dysfunction, with special focus on children with SB. The approach strategies vary across a spectrum, with a proactive strategy on one end of the spectrum and an expectant strategy at the other end. The proactive management strategy is characterized by early and frequent labs, imaging, and urodynamic (UDS) evaluation, with early initiation of clean intermittent catheterization (CIC) and proceeding with pharmacotherapy, or surgery if indicated. The expectant management strategy prioritizes surveillance labs and imaging prior to proceeding with invasive assessments and interventions such as UDS or pharmacotherapy. Both treatment strategies are currently utilized and data have historically been inconclusive in demonstrating efficacy of one regimen over the other. We performed a narrative literature evaluating proactive and expectant treatment strategies as they relate to diagnostics and management of Spina Bifida. From the available literature and our practice, a proactive strategy favors greater benefit in preventative management and may decrease risk of renal dysfunction compared with expectant management.

Integrated Ultrasound With Urodynamics Illustrates Effect of Bladder Volume on Upper Tract Dilation: Should we Trust Surveillance Ultrasounds?

OBJECTIVE

To evaluate if ultrasound during urodynamics (uUS) will show that traditional ultrasound (tUS) routinely underestimates the potential magnitude of upper tract dilation (UTD).

METHODS

Prospective pilot study of 10 consecutive patients ≥ 5 years of age undergoing same day uUS and tUS. Using randomized images, the study pediatric radiologist determined anterior-posterior renal pelvic diameter (APD), bladder volume, vesicoureteral reflux (VUR) and UTD grades. A single pediatric urologist determined urodynamic bladder capacity and assigned either hostile, intermediate, abnormal but safe, or normal national spina bifida patient registry classification (NSBPR).

RESULTS

Bladder volume on tUS was significantly smaller than final bladder volume on uUS (180 vs 363 ml: P<.001). On average, patient reported maximum catheterized/voided volumes were also 82 ml greater than final bladder capacity on uUS. UTD was upgraded in 25% of kidneys and APD increased by 0.6 cm on uUS over that seen on tUS (P=.001). Units with VUR had greater increases in APD (1.2 P=.007 vs. 0.3 cm P=0.06). Changes in APD stratified by NSBPR revealed average increases of up to 1.3 cm.

CONCLUSION

Despite instructions to the contrary, patients come for tUS with a relatively empty bladder as compared to either their urodynamic or patient-reported capacity. This translates to a significant underestimation of UTD with tUS, most notably in those with VUR. Alternatives to traditional protocols include insisting patients wait until their bladder is truly full for tUS, retrograde filling their bladder, or performing uUS. Accurate assessment of UTD severity may help guide long term management.

Virus-related neurological lower urinary tract dysfunction: Lessons learned during 4-year follow-up of patients with Congenital Zika Syndrome

INTRODUCTION

We have previously reported on neurogenic bladder dysfunction among Congenital Zika Vírus Syndrome (CZS) patients, but it is unknown how they will respond to treatment.

OBJECTIVE

To assess whether children with neurological lower urinary tract dysfunction and CZS will respond to Standard therapies.

METHODOLOGY

A prospective observational cohort study of children with CZS referred for urological assessment between 2016 and 2020 to our quaternary center in Brazil. Urological protocol included clinical history, urinalysis and culture, renal and bladder ultrasonography and urodynamic study. Patients were treated based on findings from the first evaluation, with oxybutynin chloride for overactive bladder and low bladder compliance, clean intermittent catheterization for ineffective bladder emptying, or dual therapy when both were observed. Urological outcomes were evaluated between the first and second visits considering patient's adherence. Outcomes measured included clinical, imaging, and urodynamic variables. Data was analyzed using the IBM SPSS 22 software.

RESULTS

From the cohort of 90 patients, 56 completed the second urodynamic assessment and were included. One presented underactive bladder and 55 overactive bladder. Among these 55, 39 were adherent and 16 non-adherents to the prescribed treatment. Among the 39 adherents, 8 adhered regularly to oxybutynin and clean intermittent catheterization (CIC), 29 to oxybutynin alone, and two to catheterization alone. During follow-up, the number of patients with urinary tract infection and postvoid residual increased, but all other parameters had improved. Renal and bladder ultrasonography improved in 10, maximum bladder pressure decreased in 22 and maximum cystometric capacity and compliance increased in 14 patients. Sixteen patients did not adhere regularly to the prescribed treatment and although the number of patients with urinary tract infection reduced with antibiotic therapy, their bladder capacity and compliance did not improve during follow-up.

DISCUSSION

Ultrasonographic and urodynamic improvements were observed after 10.8 ± 7.5 months of treatment, including one patient with ureterohydronephrosis that resolved. Adherence to CIC remains a challenge and reflected in the number of patients presenting urinary tract infection and postvoid residual. The immediate clinical relevance is the major study strength, given the previously uncharacterized therapy options for this patient population. The number of patients remains one of the study limitations, reducing our ability to perform more advanced statistical analyses.

CONCLUSION

Patients with Zika-related neurological lower urinary tract dysfunction may benefit from conventional therapies. Results confirmed ultrasonographic and urodynamic improvements after treatment, although not statically significant. Adherence to treatment, specifically to CIC, remains a challenge.

Urinary tract imaging in infants with spina bifida: a selective approach to a baseline DMSA

INTRODUCTION

There is no general agreement among paediatric urologists on how infants with spina bifida (SB) should be investigated after birth. Recently the EUA/ESPU guidelines have been published recommending a baseline DMSA scan in the first year of life and a Voiding Cystourethrogram (VCUG) or Videourodynamic (VUD) between the second and third month of life.

OBJECTIVE

The aim of this study was to evaluate the outcome of renal investigations in the first year of life in infants with SB to verify if an early DMSA scan is indicated in the management of this group of patients.

METHODS

All renal imaging, Renal and Bladder Ultrasound (RBUS), VCUGs, VUDs and DMSA were reviewed by two independent assessors to evaluate outcome.

RESULTS

Seventy patients with spina bifida (40 girls) were enrolled between June 2015 and February 2020. An early VUD detected vesico-ureteral reflux (VUR) in 8/49 (16%) of patients. An early VUD also gave additional information on detrusor under or over activity, bladder trabeculation, end filling detrusor pressure (EFDP) and sphincteric incompetence. DMSA scan detected renal scarring in 4/68 (6%) patients. Three of these 4 patients had significant history of febrile UTIs while the fourth patient had grade 2 left sided VUR.

CONCLUSIONS

The initial assessment of a newborn with myelodysplasia includes a Renal and Bladder Ultrasound during birth hospitalization. This study confirms the recently published EUA/ESPU guidelines on the management of neurogenic bladder in children and adolescents, which recommend a VUD or VCUG & Cystomanometry with Electromyogram (CMG) (if VUD not available) in the first 6-12 weeks of life. A selective approach to DMSA scan only in infants with SB who either had a febrile UTI or vesico-ureteric reflux would not have missed any scarring or dysplasia and would have saved 58 unnecessary nuclear scans.

[Clinical features of neurogenic bladder with vesicoureteral reflux in children]

OBJECTIVE

To study the clinical features of vesicoureteral reflux (VUR) in children with neurogenic bladder (NB), and to provide a reference for its early diagnosis and treatment.

METHODS

Clinical data were collected from 26 children with NB and urinary tract infection who were admitted to the Department of Pediatric Nephrology from January 2014 to December 2019. According to the presence or absence of VUR, the children were divided into a VUR group with 11 children and a non-VUR group with 15 children. Clinical features were compared between the two groups.

RESULTS

Compared with the non-VUR group, the VUR group had a significantly higher proportion of children with non-Escherichia coli urinary tract infection, hydronephrosis (the severity of hydronephrosis increased with the grade of VUR), abnormal ^99mTc-DMSA renal scanning findings, elevated ratios of urinary albumin, urinary IgG and urinary transferrin to creatinine, increased residual urine volume, and increased detrusor leak point pressure (P < 0.05).

CONCLUSIONS

When NB children have the clinical manifestations of non-Escherichia coli urinary tract infection, hydronephrosis, abnormal ^99mTc-DMSA renal scanning findings, glomerular proteinuria, increased bladder residual urine volume, and high detrusor leak point pressure, such children may already have VUR, and so diagnosis and intervention should be performed as early as possible.

Non-invasive markers in the management of pediatric neurogenic bladder over the last two decades - A review

Neurogenic bladder (NB) is one of the most challenging problems in nephro-urological management in pediatrics. It is an important risk factor of secondary upper urinary tract damage. A complete clinical evaluation is necessary and requires life-long extensive medical attention including invasive procedures that affect patients' quality of life. Potential non-invasive biomarkers would be desirable, especially in the pediatric population. The aim of this review was to analyze two decades of data regarding potential non-invasive biomarkers in the assessment and follow-up of children with NB. This paper summarizes and appraises the knowledge about both biochemical and imaging-based markers in 3 aspects: markers of urinary tract infections (UTIs), bladder and renal function, and this paper looks at their prospective application in everyday clinical care.

Functional Evaluation of Upper Urinary Tract with Diuretic Mercaptoacetyltriglycine Renal Scans in Patients with Benign Prostatic Obstruction before and after Surgical Intervention: A Pilot Study

Introduction

We investigated which benign prostatic hyperplasia-related lower urinary parameters are related to upper urinary tract obstruction and whether transurethral prostatectomy could improve upper urinary tract obstruction.

Materials and Methods

Patients with prostate size over 30 g and urodynamically proven bladder outlet obstruction were enrolled in this prospective observational study. Bladder wall thickness and prostate size were measured by ultrasonography. A urodynamic study with laboratory tests including serum creatinine, prostate-specific antigen, and urinalysis was performed. Finally, a diuretic scintigraphy using mercaptoacetyltriglycine was performed. Tests except the urodynamic evaluation were repeated after transurethral prostatectomy.

Results

In total, 24 patients were enrolled, and 19 patients completed the present study. The mean values of age (yrs), prostate size (mL), bladder thickness (mm), bladder compliance (ΔmL/Δpr), and the bladder outlet obstruction index were 68.42 ± 8.25, 72.29 ± 32.78, 4.42 ± 1.14, 50.17 ± 32.15, and 82.11 ± 34.68, respectively. The mean T_1/2 (min) was 17.51 ± 16.34 on the left side and 15.30 ± 11.96 on the right side. Statistical analysis showed that bladder compliance and bladder thickness were preoperatively related to upper urinary tract obstruction (p = 0.001 and p = 0.007, respectively). Diuretic mercaptoacetyltriglycine scan in 19 patients showed improvement 6 months after prostate surgery. Clinically significant proteinuria was associated with upper urinary tract obstruction, and proteinuria was also improved after prostate surgery.

Conclusion

Storage-phase bladder dysfunction could be a reliable urodynamic factor for the indication of upper urinary tract obstruction in patients with benign prostatic hyperplasia, and upper urinary tract obstruction with subsequent kidney damage could be improved by surgical decompression of benign prostatic obstruction.