Bladder Volume at Onset of Vesicoureteral Reflux is an Independent Risk Factor for Breakthrough Febrile Urinary Tract Infection

The impact of the distal ureteral diameter ratio, bladder volume at onset of vesicoureteral reflux, and/or grade in predictive models of clinical outcomes in children with vesicoureteral reflux

PURPOSE

Vesicoureteral reflux (VUR) grade has been used as a primary factor in assessing a child's risk of clinical outcomes. Unfortunately, grade has poor inter-observer reliability. We hypothesized that more objective and reliable VCUG parameters including the distal ureteral diameter ratio (UDR) and volume at onset of VUR (Vol) may either augment or replace the current grading system to provide more reliable prediction of clinical outcomes.

MATERIALS AND METHODS

Multivariate clinical outcome models were analyzed to assess the impact on predictive accuracy by the addition of voiding cystourethrogram (VCUG) data including grade, UDR, and Vol, alone or in combinations. Clinical variables from retrospective review of 841 children's records included age, gender, presentation, VUR laterality, bowel and bladder dysfunction, history of febrile urinary tract infection (UTI), and number of UTIs. The primary outcomes assessed included VUR resolution or persistence and need for operative intervention.

RESULTS

Grade, UDR, and Vol were independent predictors of resolution and operative intervention. Vol increased predictive accuracy in resolution models with grade or UDR alone; however, no significant difference occurred in models with the substitution of grade with UDR.

CONCLUSIONS

A more reliable classification system for VUR, with improved predictive accuracy regarding clinical outcomes, may be developed incorporating UDR and Vol. Whether VUR grade can be completely replaced by Vol and UDR measurements requires further evaluation with larger number of patients.

Update on imaging recommendations in paediatric uroradiology: the European Society of Paediatric Radiology workgroup session on voiding cystourethrography

Voiding cystourethrography (VCUG) is a fluoroscopic technique that allows the assessment of the urinary tract, including the urethra, bladder, and-if vesicoureteral reflux (VUR) is present-the ureters and the pelvicalyceal systems. The technique also allows for the assessment of bladder filling and emptying, providing information on anatomical and functional aspects. VCUG is, together with contrast-enhanced voiding urosonography (VUS), still the gold standard test to diagnose VUR and it is one of the most performed fluoroscopic examinations in pediatric radiology departments. VCUG is also considered a follow-up examination after urinary tract surgery, and one of the most sensitive techniques for studying anatomy of the lower genitourinary tract in suspected anatomical malformations. The international reflux study in 1985 published the first reflux-protocol and graded VUR into five classes; over the following years, other papers have been published on this topic. In 2008, the European Society of Paediatric Radiology (ESPR) Uroradiology Task Force published the first proposed VCUG Guidelines with internal scientific society agreement. The purpose of our work is to create a detailed overview of VCUG indications, procedural recommendations, and to provide a structured final report, with the aim of updating the 2008 VCUG paper proposed by the European Society of Paediatric Radiology (ESPR). We have also compared VCUG with contrast-enhanced VUS as an emergent alternative. As a result of this work, the ESPR Urogenital Task Force strongly recommends the use of contrast-enhanced VUS as a non-radiating imaging technique whenever indicated and possible.

Upper urinary tract function of patients with multiple sclerosis

BACKGROUND

Neurogenic lower urinary tract dysfunction (NLUTD) is frequent in multiple sclerosis (MS) and renal prognosis is a key point of bladder management.

OBJECTIVE

To assess upper urinary tract damage risk using voiding cystourethrography (VCUG) in patients with (PwMS) and NLUTD.

METHODS

We conducted a retrospective study between 2010 and 2020. Demographic data, urinary symptoms, urinary tract infection (UTI), renal ultrasounds findings, glomerular filtration rate (GFR), VCUG data, and urodynamic parameters were collected in PwMS with NLUTD.

RESULTS

Among 325 PwMS included, 67% were female, mean age was 51.6 ± 12.0 years, and mean EDSS 4.6 ± 1.8. VCUG showed vesicoureteral reflux (VUR) in 18 patients. A link was found between VUR and progressive MS course (p = 0.04), hydronephrosis (odds ratio [OR] = 17.44; 95% confidence interval [CI] = 3.46-87.87; p = 0.001), low GFR (p < 0.001), and detrusor overactivity (p = 0.04). No association with UTIs, EDSS, detrusor sphincter dyssynergia, were elicited. On multivariate analysis, alteration of GFR was independently related to the presence of VUR (OR = 0.95; 95% CI = 0.92-0.98).

CONCLUSIONS

VUR elicited on VCUG is associated with lower GFR and hydronephrosis. However, due to the low prevalence (5.5%) of this abnormality in PwMS, VCUG should be performed in selected cases and not in routinary practice.

Abnormal DMSA renal scan findings and associated factors in older children with vesicoureteral reflux

AIM

There are scanty data on the rate of abnormal Tc-99 m dimercaptosuccinic acid (DMSA) renal scintigraphy and associated factors in children older than 5 years with diagnosis of VUR. We do not have knowledge about which older children should undergo DMSA after VUR diagnosis. This study aims to assess the rate of abnormal DMSA findings and associated factors in children older than 5 years of age diagnosed with VUR.

MATERIALS AND METHODS

We retrospectively reviewed the medical records of 258 children with VUR diagnosed at or older than 5 year age. 179 children [42 (23.5%) males and 137 (76.5%) females] with complete data were included. 268 reflux units were compared according to gender, bilaterality, grade, reflux phase at voiding cystourethrography, febrile urinary tract infection (fUTI), lower urinary tract dysfunction (LUTD), and DMSA findings with uni- and multivariate analysis.

RESULTS

The median age was 110 (60-216) months. VUR grades were I, II, and III in 197 (73.6%) units and IV-V in 71 (26.4%). 138 (51.5%) renal units had abnormal DMSA. VUR grade (p < 0.01), unilaterality (p = 0.048), and fUTI (p = 0.031) in univariate but only grade and unilaterality in multivariate analysis are significantly associated with abnormal DMSA. Although reflux at filling phase was predominant in high-grade VUR group, reflux at voiding phase (p = 0.006) in low-medium-grade (1-3) VUR was associated with abnormal DMSA.

CONCLUSION

Children older than 5 years of age diagnosed with VUR should be regarded as a high-risk group for abnormal DMSA regardless of gender, unilaterality, grade, reflux phase, fUTI, and LUTD.

Additional VCUG-related parameters for predicting the success of endoscopic injection in children with primary vesicoureteral reflux

INTRODUCTION AND OBJECTIVE

Prediction of vesicoureteral reflux (VUR) prognosis and decision for treatment are usually made according to the reflux grading classification. But the management of VUR is still controversial since there are difficulties in distinguishing reflux grade due to inter- and intra-observer variations. Previous studies have demonstrated that the distal ureteral diameter ratio (UDR) on voiding cystourethrography (VCUG) may be more predictive for clinical prognosis than reflux grade. We aimed to predict the success of endoscopic injection in primary VUR by creating new models that include other additional parameters (timing of reflux, delayed post-voiding contrast drainage of the upper urinary tract) as well as UDR.

STUDY DESIGN

A total of 200 patients aged 2-15 years with primary VUR undergoing endoscopic injection were retrospectively evaluated. Demographic and clinical data for a total of 248 renal units were recorded. Besides reflux grade and laterality, distal ureteral diameter, UDR, timing of reflux [early filling, late filling or voiding] and presence of contrast delay in upper tract drainage were also assessed on VCUG. According to the complete resolution of VUR on the control VCUG at the postoperative 3rd month, the renal units were divided into two main groups: successful (n = 171, 68.9%) and unresolved (n = 77, 31.1%) RESULTS: The failure rate of endoscopic injection was found to be 4.068 times greater with early filling reflux on VCUG, 3.076 times greater with UDR>0.24, 2.745 times greater with delayed contrast drainage of the upper urinary tract, 2.666 times greater with the presence of scar in DMSA, 2.493 times greater with bladder-bowel dysfunction and 2.341 times greater with febrile urinary tract infection. We also observed that a model in which all VCUG-related parameters were combined provided a better estimation of endoscopic injection outcomes compared to only the reflux grade (AUC: 0.903 vs. 0.604, respectively).

DISCUSSION

Distal ureteral dilatation is considered to be a more decisive factor for clinical outcomes of primary VUR rather than upper urinary tract dilatation since ureterovesical junction anatomy plays a more important role in primary VUR pathophysiology. Studies investigating new prediction models on this topic have recently become more popular. However, a consensus has not yet been achieved.

CONCLUSION

We consider that UDR level, the timing of reflux and delayed upper tract drainage on VCUG may be more predictive parameters of endoscopic injection success compared with reflux grade, and could facilitate selecting the best candidates for surgery.

Standardized protocol for voiding cystourethrogram: Are recommendations being followed?

BACKGROUND

Voiding cystourethrogram (VCUG) images the urethra and bladder during filling and emptying, as well as ureters and kidneys when vesicoureteral reflux (VUR) is present, providing detailed information about both anatomical and functional status of the urinary tract. Given the importance of information obtained, and the varying quality depending on VCUG technique and radiology reporting, the American Academy of Pediatrics Sections on Urology and Radiology published a joint standardized VCUG protocol in 2016.

OBJECTIVE

We compared VCUG reports from multiple institutions before and after publication of the protocol to determine adherence to recommendations.

STUDY DESIGN

VCUG reports generated during two separate time periods were assessed - before and after publication - to evaluate impact of the protocol. Adherence to the reporting template was evaluated. Studies performed on patients >18 years of age and those obtained for trauma evaluation were excluded from study.

RESULTS

A total of 3121 VCUG reports were analyzed, 989 (31.7%) were generated before and 2132 (68.3%) after protocol publication. Comparing cohorts, there was no difference in gender (62.6% female versus 61.4%; p = 0.53) though children in the post-cohort were slightly older (3.34 ± 3.82 versus 3.68 ± 4.19 years; p = 0.03). A significant increase in scout image reporting (91.5%) and cyclic studies (20.5%) were observed in the post-cohort, in comparison to 79.2% and 13.1%, respectively, in the pre-protocol cohort (p < 0.001) [Figure]. Measured PVR and recorded infused volume actually decreased between study periods (84.7% vs 72.8% and 97.2% vs 91.5%, p < 0.001). There was no statistically significant difference between VUR grade reporting (99.4 vs 98.5%, p = 0.25). Recorded volume in which reflux occurred increased between periods (0.6% vs 2.3%, p < 0.05), while reporting of filling vs voiding reflux decreased in the post-cohort (84.4% pre-vs 77.4% post-protocol, p < 0.008).

DISCUSSION

The 2016 VCUG protocol recommended inclusion of various data points, however the volume at which reflux occurs remained vastly underreported. Timing of reflux has been shown to predict likelihood of spontaneous resolution and risk of breakthrough urinary tract infection; thus, its omission may limit the information used to counsel families and provide individualized care.

CONCLUSION

Despite consensus on standard VCUG protocol to best perform and record data, reports remain inconsistent. While VUR grade is routinely reported, other important anatomic and functional findings which are known to impact resolution and breakthrough urinary tract infection rates, such as volume at which reflux occurs, are consistently underreported.

Management of Vesicoureteral Reflux: What Have We Learned Over the Last 20 Years?

Vesicoureteral reflux (VUR) is associated with increased risks of urinary tract infection, renal scarring and reflux nephropathy. We review advancements over the last two decades in our understanding and management of VUR. Over time, the condition may resolve spontaneously but it can persist for many years and bladder/bowel dysfunction is often involved. Some factors that increase the likelihood of persistence (e.g., high grade) also increase the risk of renal scarring. Voiding cystourethrography (VCUG) is generally considered the definitive method for diagnosing VUR, and helpful in determining the need for treatment. However, this procedure causes distress and radiation exposure. Therefore, strategies to reduce clinicians' reliance upon VCUG (e.g., after a VUR treatment procedure) have been developed. There are several options for managing patients with VUR. Observation is suitable only for patients at low risk of renal injury. Antibiotic prophylaxis can reduce the incidence of UTIs, but drawbacks such as antibiotic resistance and incomplete adherence mean that this option is not viable for long-term use. Long-term studies of endoscopic injection have helped us understand factors influencing use and the effectiveness of this procedure. Ureteral reimplantation is still performed commonly, and robot-assisted laparoscopic methods are gaining popularity. Over the last 20 years, there has been a shift toward more conservative management of VUR with an individualized, risk-based approach. For continued treatment improvement, better identification of children at risk of renal scarring, robust evidence regarding the available interventions, and an improved VUR grading system are needed.

Accuracy of subjective vesicoureteral reflux timing assessment: supporting new voiding cystourethrogram guidelines

BACKGROUND

Bladder volume at the onset of vesicoureteral reflux (VUR) is an important prognostic indicator of spontaneous resolution and the risk of pyelonephritis.

OBJECTIVE

We aim to determine whether pediatric urologists and pediatric radiologists can accurately estimate the timing of reflux by examining voiding cystourethrogram (VCUG) images without prior knowledge of the instilled contrast volume.

MATERIALS AND METHODS

Total bladder volume and the volume at the time of reflux were collected from VCUG reports to determine the volume at the onset of VUR. Thirty-nine patients were sorted into three groups: early-/mid-filling reflux, late-filling and voiding only. Thirty-nine images were shown to three pediatric urologists and two pediatric radiologists in a blinded fashion and they were then asked to estimate VUR timing based on the above categories. A weighted kappa statistic was calculated to assess rater agreement with the gold standard volume-based report of VUR timing.

RESULTS

The mean patient age at VCUG was 3.1±2.9 months, the median VUR was grade 3, and 20 patients were female. Overall agreement among all five raters was moderate (k=0.43, 95% confidence interval [CI] 0.36-0.50). Individual agreement between rater and gold standard was slight to moderate with kappa values ranging from 0.13 to 0.43.

CONCLUSION

Pediatric radiologists and urologists are unable to accurately and reliably characterize VUR timing on fluoroscopic VCUG. These findings support the recently published American Academy of Pediatrics protocol recommending the routine recording of bladder volume at the onset of VUR as a standard component of all VCUGs to assist in a more accurate assessment of the likelihood of resolution and risk of recurrent urinary tract infections.

The ABCs of Voiding Cystourethrography

Voiding cystourethrography (VCUG) demonstrates the anatomy of the urinary system and is used to detect the presence/absence of vesicoureteral reflux. It is the most important modality for urological fluoroscopic examination in children. For improved patient care, it is important to understand and perform VCUG appropriately. Therefore, an in-depth review of VCUG protocols and techniques has been presented herein. In addition, tips, tricks, and pitfalls associated with the technique have also been addressed.

Prevalence of Bladder and Bowel Dysfunction in Toilet-Trained Children With Urinary Tract Infection and/or Primary Vesicoureteral Reflux: A Systematic Review and Meta-Analysis

Introduction: Urinary tract infection (UTI) in children leads to renal scarring in 10-15% of patients. Urinary tract anomalies and bladder and bowel dysfunction (BBD) are documented risk factors for recurrent UTIs. Estimates of baseline prevalence of BBD in children with UTI will help the clinician in the management strategy. Hence, a systematic review and meta-analysis was conducted to estimate the pooled prevalence of BBD. Methods: MEDLINE, EMBASE, and CENTRAL (Cochrane Central Register of Controlled Trials) databases were searched for articles related to UTI, primary vesicoureteral reflux (VUR), and BBD. We included studies that provided prevalence of BBD in toilet-trained patients aged 1-18 years with UTI and/or VUR. BBD was defined based on clinical history or questionnaire or urodynamic studies. Two authors independently reviewed, assessed, and abstracted data from studies. Pooled prevalence was calculated based on a random effects model. Results: Forty-three studies fulfilling the eligibility criteria were selected from a total of 1,731 studies. Among patients presenting with UTI without primary VUR, pooled prevalence of BBD was 41% (95% CI: 26-55; nine studies, 920 patients, I ² = 96.0%), whereas its prevalence in patients with primary VUR was 49% (43-56; 30 studies, 5,060 patients, I ² = 96.0%). Weighting by the study design and quality did not affect the prevalence. In patients with primary VUR, prevalence of BBD was higher in females (53%; 42-65) than in males (44%; 15-73). In studies where urodynamic study was used for the diagnosis of BBD, prevalence was 63%. The presence of BBD in patients with primary VUR increased risk of recurrent UTIs [relative risk (RR): 2.1; 1.7-2.5]. In five studies that reported separate data on constipation, pooled prevalence of constipation was 27% (16-37). Conclusion: Almost half of the patients with primary VUR have BBD, and its presence increases the risk of recurrent UTIs. Trends of high BBD prevalence were also observed in patients presenting with UTI without VUR. These prevalence estimates suggest that all toilet-trained children presenting with UTI with or without VUR should be assessed for BBD, which will help in their further management.

New trends in voiding cystourethrography and vesicoureteral reflux: Who, when and how?

Vesicoureteral reflux, retrograde flow of urine from the bladder into the upper urinary tract, is one of the most common urological diagnoses in the pediatric population. Diagnosis and subsequent management of urinary reflux have become increasingly debated in the past decade, with divergent opinions over which patients should be evaluated for reflux, and when detected, which children should receive intervention. Although some argue that vesicoureteral reflux is a "phenotype" that often resolves without intervention, others contest that untreated reflux has the potential to cause irreversible renal damage over time. Voiding cystourethrogram images the urethra and bladder during both bladder filling and emptying, as well as the ureters and kidneys when reflux is present, and is considered the gold standard for diagnosing vesicoureteral reflux. Once detected, therapeutic options for urinary reflux are diverse, ranging from observation with or without low-dose antibiotic prophylaxis to a variety of operative interventions. Management should be based on a multitude of factors including patient age, risk of subsequent urinary tract infections, risk of renal parenchymal injury, a given child's projected clinical course and parental preference. Over the past two decades, investigators have elucidated many crucial voiding cystourethrogram findings in addition to grade that provide significant prognostic information and are useful in determining the best course of action for a child on a more individualized basis.

Pediatric voiding cystourethrography: An essential examination for urologists but a terrible experience for children

Voiding cystourethrography is the most important fluoroscopic examination in pediatric urology for the investigation of lower urogenital tract diseases, such as vesicoureteral reflux or urethral stricture. However, this invasive procedure imposes a significant burden on children and their parents, and recently there has been a paradigm shift in the diagnosis and treatment of vesicoureteral reflux. In the 2011 revision, the American Academy of Pediatrics guidelines on urinary tract infection recommended abandoning routine voiding cystourethrography after the first febrile urinary tract infection. In 2014, the randomized intervention for children with vesicoureteral reflux study recommended discontinuation of routine continuous antibiotic prophylaxis for vesicoureteral reflux. The time is now ripe to radically reconsider indications for voiding cystourethrography and the procedure itself.

Diagnosis and management of bladder bowel dysfunction in children with urinary tract infections: a position statement from the International Children's Continence Society

BACKGROUND

We present a consensus view from the International Children's Continence Society (ICCS) on the evaluation and management of bladder bowel dysfunction (BBD) in children with urinary tract infection (UTI). The statement aims to highlight the importance of BBD in the development and recurrence of childhood UTI and its management to reduce its associated morbidity and sequelae.

METHODS

A systematic literature search was done on PubMed, Embase, and Scopus databases until August 15, 2016. Relevant publications concerning BBD and its relationship with UTI among children were reviewed and aggregated for statements of recommendation. Discussion by the ICCS Board and a multi-disciplinary core group of authors resulted in a document available on its website for all ICCS members to review. Insights and feedback were considered with consensus and agreement reached to finalize this position statement.

RESULTS

BBD in children with UTI is summarized. Details regarding epidemiology, pathophysiology, and recommendations for general and family practitioners and pediatricians relating to the evaluation and management of this condition are presented.

CONCLUSIONS

This document serves as the position statement from ICCS, based on literature review and expert opinion providing our current understanding of BBD in children with UTI.

Reflux Timing Is a Predictor of Successful Endoscopic Treatment of Vesicoureteral Reflux

OBJECTIVE

To determine whether vesicoureteral reflux (VUR) that occurs during either the filling or voiding phase on voiding cystourethrogram (VCUG) has prognostic significance on successful endoscopic treatment.

MATERIALS AND METHODS

A retrospective review was performed of 299 patients (438 ureters) with VUR who underwent endoscopic treatment with dextranomer/hyaluronic acid copolymer (Deflux) at a single institution from 2010 to 2013. Success was defined as absence of VUR on 3-month follow-up VCUG. Preoperative VCUGs were analyzed to determine whether the onset of VUR occurred during the filling or voiding phase. Predictor variables to determine success were analyzed, with a specific focus on VUR timing.

RESULTS

Success rate was 319/438 (72.8%) by ureter and 202/299 (67.6%) by patient. Reflux was seen during the filling and voiding phases in 290 and 148 ureters, respectively. Success rate was 203/290 (78%) for filling VUR and 116/148 (70%) for voiding VUR. Univariable analysis revealed voiding VUR had significantly increased odds of success (odds ratio [OR] 3.2, P = .049), while high-grade reflux (OR 0.53, P = .005) had significantly decreased odds of success. Multivariable analysis showed that voiding VUR (OR 3.2, P = .005) had significantly higher odds of success while those with high grade reflux (OR 0.42, P = .017) had significantly decreased odds of success.

CONCLUSION

The timing of VUR on preoperative VCUG appears to be an important independent predictor of successful endoscopic treatment of VUR. This has important clinical considerations when selecting VUR patients who would be best candidates for endoscopic treatment.

Validation of the ureteral diameter ratio for predicting early spontaneous resolution of primary vesicoureteral reflux

INTRODUCTION AND OBJECTIVE

Management of primary vesicoureteral reflux (VUR) remains controversial, and reflux grade currently constitutes an important prognostic factor. Previous reports have demonstrated that distal ureteral diameter ratio (UDR) may be more predictive of outcome than vesicoureteral reflux (VUR) grade. We performed an external validation study in young children, evaluating early spontaneous resolution rates relative to reflux grade and UDR.

STUDY DESIGN

Voiding cystourethrograms (VCUGs) were reviewed. UDR was computed by measuring largest ureteral diameter within the pelvis and dividing by the distance between the L1 and L3 vertebral bodies (Figure). VUR grade and UDR were tested in univariate and multivariable analyses. Primary outcome was status of VUR at last clinical follow-up (i.e. resolution, persistence, or surgical intervention). Demographics, VUR timing, laterality, and imaging indication were also assessed.

RESULTS

One-hundred and forty-seven children (98 girls, 49 boys) were diagnosed with primary VUR at a mean age of 5.5 ± 4.7 months. Sixty-seven (45.6%) resolved spontaneously, 55 (37.4%) had persistent disease, and 25 (17%) were surgically corrected. Patients who spontaneously resolved had significantly lower VUR grade, refluxed later during bladder filling, and had significantly lower UDR. In a multivariable model, grade of VUR (p = 0.001), age <12 months (p = 0.008), ureteral diameter (p = 0.02), and UDR (p < 0.0001) achieved statistical significance. For every 0.1 unit increase in UDR, there was a 2.6 (95% CI 1.58-4.44) increased odds of persistent VUR, whereas a 1.6 (95% CI 0.9-3.0) increased odds was observed for every unit increase in grade.

DISCUSSION

Both grade of reflux and UDR were statistically significant in a multivariable model; however, UDR had a higher likelihood ratio and was more predictive of early spontaneous resolution than grade alone. Furthermore, unlike traditional VUR grading where children with grade 1-5 may outgrow reflux depending on other factors, there appears to be a consistent UDR cutoff whereby patients are unlikely to resolve. In the present study, no child with a UDR greater than 0.43 experienced early spontaneous resolution, and only three (4.5%) of those with spontaneous resolution had a UDR above 0.35.

CONCLUSIONS

UDR correlates with reflux grade, and is predictive of early resolution in children with primary VUR. UDR is an objective measurement of VUR, and provides valuable prognostic information about spontaneous resolution, facilitating more individualized patient care.

Distal Ureteral Diameter Ratio is Predictive of Breakthrough Febrile Urinary Tract Infection

PURPOSE

Distal ureteral diameter ratio is an objective measure that is prognostic of spontaneous resolution of vesicoureteral reflux. Along with likelihood of resolution, improved identification of children at risk for recurrent febrile urinary tract infections may impact management decisions. We evaluated the usefulness of ureteral diameter ratio as a predictive factor for breakthrough febrile urinary tract infections.

MATERIALS AND METHODS

Children with primary vesicoureteral reflux and detailed voiding cystourethrogram were identified. Ureteral diameter ratio was computed by measuring largest ureteral diameter within the pelvis and dividing by the distance between L1 and L3 vertebral bodies. Demographics, vesicoureteral reflux grade, laterality, presence/absence of bladder-bowel dysfunction, and ureteral diameter ratio were tested in univariate and multivariable analyses. Primary outcome was breakthrough febrile urinary tract infections.

RESULTS

We analyzed 112 girls and 28 boys with a mean ± SD age of 2.5 ± 2.3 years at diagnosis. Vesicoureteral reflux was grade 1 to 2 in 64 patients (45.7%), grade 3 in 50 (35.7%), grade 4 in 16 (11.4%) and grade 5 in 10 (7.2%). Mean ± SD followup was 3.2 ± 2.7 years. A total of 40 children (28.6%) experienced breakthrough febrile urinary tract infections. Ureteral diameter ratio was significantly greater in children with (0.36) vs without (0.25) breakthrough febrile infections (p = 0.004). Controlling for vesicoureteral reflux grade, every 0.1 U increase in ureteral diameter ratio resulted in 1.7 times increased odds of breakthrough infection (95% CI 1.24 to 2.26, p <0.0001).

CONCLUSIONS

Children with increased distal ureteral diameter ratio are at greater risk for breakthrough febrile urinary tract infections independent of reflux grade. Ureteral diameter ratio provides valuable prognostic information about risk of recurrent pyelonephritis and may assist with clinical decision-making.

Application of the Strengthening the Reporting of Observational Studies in Epidemiology (STROBE) statement to publications on endoscopic treatment for vesicoureteral reflux

OBJECTIVE

Following an increasing number of submissions on endoscopic treatment of vesicoureteral reflux (VUR), the Journal of Pediatric Urology sought to establish a quality guideline that would enable reviewers to select the best papers for publication in the journal. The "Strengthening the Reporting of Observational Studies in Epidemiology" (STROBE) Statement, established in 2007, is a 22-item checklist designed to assist with clear reporting of observational studies. This checklist includes a description of methodological items and instructions on how to use them to transparently report observational studies. The aim of the present study was to apply the STROBE principle to observational studies about endoscopic management of VUR, and to establish a "check-list" to assist authors with good-quality submissions.

STUDY DESIGN

The 22 STROBE criteria were listed and applied to publications on endoscopic treatment by utilizing examples from the current literature, with additional suggestions about how future studies could build upon the information already published on the subject.

RESULTS

Based on this strategy, a checklist that is particular to endoscopic treatment studies was produced as a guideline for authors and reviewers.

DISCUSSION

Application of the STROBE statement principles, in combination with key VUR data, will allow better quality submissions and a higher chance of positive reviews and acceptance rates.

Imaging studies and biomarkers to detect clinically meaningful vesicoureteral reflux

The work-up of a febrile urinary tract infection is generally performed to detect vesicoureteral reflux (VUR) and its possible complications. The imaging modalities most commonly used for this purpose are renal-bladder ultrasound, voiding cystourethrogram and dimercapto-succinic acid scan. These studies each contribute valuable information, but carry individual benefits and limitations that may impact their efficacy. Biochemical markers are not commonly used in pediatric urology to diagnose or differentiate high-risk disease, but this is the emerging frontier, which will hopefully change our approach to VUR in the future. As it becomes more apparent that there is tremendous clinical variation within grades of VUR, the need to distinguish clinically significant from insignificant disease grows. The unfortunate truth about VUR is that recommendations for treatment may be inconsistent. Nuances in clinical decision-making will always exist, but opinions for medical versus surgical intervention should be more standardized, based on risk of injury to the kidney.

Vesicoureteral Reflux Index: Predicting Primary Vesicoureteral Reflux Resolution in Children Diagnosed after Age 24 Months

PURPOSE

The Vesicoureteral Reflux Index is a validated tool that reliably predicts spontaneous resolution of reflux or at least 2 grades of improvement for patients diagnosed before age 24 months. We evaluated the Vesicoureteral Reflux Index in children older than 2 years.

MATERIALS AND METHODS

Patients younger than 18 years who were diagnosed with primary vesicoureteral reflux after age 24 months and had undergone 2 or more voiding cystourethrograms were identified. Disease severity was scored using the Vesicoureteral Reflux Index, a 6-point scale based on gender, reflux grade, ureteral abnormalities and reflux timing. Proportional subdistribution hazard models for competing risks identified variables associated with resolution/improvement at different time points.

RESULTS

A total of 21 males and 250 females met inclusion criteria. Mean ± SD age was 4.0 ± 2.1 years and patients had a median vesicoureteral reflux grade of 2. The Vesicoureteral Reflux Index score improved by 1 point in 1 patient (100%), 2 points in 25 (67.6%), 3 points in 48 (37%), 4 points in 18 (21.4%) and 5 to 6 points in 4 (18.2%). Female gender (p = 0.005) and vesicoureteral reflux timing (late filling, p = 0.002; early/mid filling, p <0.001) independently predicted nonresolution. Median resolution time based on Vesicoureteral Reflux Index score was 2 months or less in 15.6% of patients (95% CI 11.0-13.8), 3 months in 34.7% (95% CI 25.4-44.1), 4 months in 55.9% (95% CI 40.1 to infinity) and 5 months or more in 30.3% (95% CI 29.5 to infinity). High grade (IV or V) reflux was not associated with resolution at any point. Ureteral abnormalities were associated with lack of resolution in the first 12 to 18 months (HR 0.29, 95% CI 0.29-0.80) but not in later followup. Vesicoureteral Reflux Index scores of 3, 4 and 5 were significantly associated with lack of resolution/improvement compared to scores of 2 or less (p = 0.031).

CONCLUSIONS

The Vesicoureteral Reflux Index reliably predicts primary vesicoureteral reflux improvement/resolution in children diagnosed after age 24 months. Spontaneous resolution/improvement is less likely as Vesicoureteral Reflux Index score and time from diagnosis increase.

Establishing a standard protocol for the voiding cystourethrography

The voiding cystourethrogram (VCUG) is a frequently performed test to diagnose a variety of urologic conditions, such as vesicoureteral reflux (VUR). The test results determine whether continued observation or an interventional procedure is indicated. VCUGs are ordered by many specialists and primary care providers, including pediatricians, family practitioners, nephrologists, hospitalists, emergency room physicians, and urologists. Current protocols for performing and interpreting a VCUG are based on the International Reflux Study in 1985. However, more recent information provided by many national and international institutions suggests a need to refine those recommendations. The lead author of the 1985 study, R.L. Lebowitz, agreed to and participated in the current protocol. In addition, a recent survey directed to the chairpersons of pediatric radiology of 65 children's hospitals throughout the United States and Canada showed that VCUG protocols vary substantially. Recent guidelines from the American Academy of Pediatrics (AAP) recommend a VCUG for children between 2 and 24 months of age with urinary tract infections but did not specify how this test should be performed. To improve patient safety and to standardize the data obtained when a VCUG is performed, the AAP Section on Radiology and the AAP Section on Urology initiated the current VCUG protocol to create a consensus on how to perform this test.

Establishing a Standard Protocol for the Voiding Cystourethrography

The voiding cystourethrogram (VCUG) is a frequently performed test to diagnose a variety of urologic conditions, such as vesicoureteral reflux. The test results determine whether continued observation or an interventional procedure is indicated. VCUGs are ordered by many specialists and primary care providers, including pediatricians, family practitioners, nephrologists, hospitalists, emergency department physicians, and urologists. Current protocols for performing and interpreting a VCUG are based on the International Reflux Study in 1985. However, more recent information provided by many national and international institutions suggests a need to refine those recommendations. The lead author of the 1985 study, R.L. Lebowitz, agreed to and participated in the current protocol. In addition, a recent survey directed to the chairpersons of pediatric radiology of 65 children's hospitals throughout the United States and Canada showed that VCUG protocols vary substantially. Recent guidelines from the American Academy of Pediatrics (AAP) recommend a VCUG for children between 2 and 24 months of age with urinary tract infections but did not specify how this test should be performed. To improve patient safety and to standardize the data obtained when a VCUG is performed, the AAP Section on Radiology and the AAP Section on Urology initiated the current VCUG protocol to create a consensus on how to perform this test.

Delayed upper tract drainage on voiding cystourethrogram may not be associated with increased risk of urinary tract infection in children with vesicoureteral reflux

INTRODUCTION

Urinary stasis in the setting of obstruction provides an opportunistic environment for bacterial multiplication and is a well-established risk factor for UTI. Vesicoureteral reflux (VUR) with delayed upper tract drainage (UTD) on VCUG has been reported to correlate with increased UTI risk. We sought to determine whether delayed UTD can be reliably classified, and whether it correlates with UTI incidence, VCUG, or endoscopic findings.

METHODS

Children undergoing endoscopic surgery for primary VUR (2009-2012) were identified. VUR grade, timing, and laterality were abstracted. Demographics, hydrodistention (HD) grade, reported febrile and culture-proven UTI were assessed. UTD on VCUG was graded on post-void images as 1 = partial/complete UTD or 2 = no/increased UTD. Inter-observer agreement was calculated. Patients were excluded for incomplete imaging or inability to void during VCUG.

RESULTS

The cohort included 128 patients (10M, 118F), mean age 4.1 ± 2.1 years. Mean age at diagnosis was 2.8 ± 2.8 years. Mean maximum VUR grade was 3 ± 0.9: 1 (7.8%), 2 (20.3%), 3 (43%), 4 (25.8%), 5 (3.1%). UTD occurred in 45 (35%), and no drainage in 83 (65%) patients. Agreement coefficient between graders was 0.596 (p < 0.0001). Cultures were available in 100 patients (70 positive). Patients experienced a mean of 2 ± 1.2 parent-reported fUTIs and 1.2 ± 1.2 culture-proven UTIs from birth to surgery. UTI rate did not differ by UTD status for parent or culture-proven UTI (Table). On multivariate analysis, no patient characteristic was a significant predictor of UTI based on drainage status. Children diagnosed with VUR before 1 year of age had a higher verified UTI rate (p < 0.001). However, drainage was not a significant predictor of UTI rate and when testing the interaction of drainage and age.

CONCLUSION

We sought to determine whether UTD was an accurate predictor of UTI risk to maximize available prognostic information from a single VCUG. Delayed UTD was not a predictor of infection in our patients, nor was it associated with previously described UTI risk factors, such as VUR timing or grade, and voiding dysfunction. Limitations included the retrospective nature of the study in patients undergoing endoscopic VUR treatment, and possible inaccurate UTI reports from parents and pediatricians. UTD can be reliably scored using a binary system with high inter-observer correlation. Our data call into question the previous finding that children with poor UTD are at increased risk of recurrent UTI. Delayed UTD is also not associated with higher HD, or VUR grade compared with those with more prompt UTD.

Computer model predicting breakthrough febrile urinary tract infection in children with primary vesicoureteral reflux

INTRODUCTION AND OBJECTIVE

Factors influencing the decision to surgically correct vesicoureteral reflux (VUR) include risk of breakthrough febrile urinary tract infection (fUTI) or renal scarring, and decreased likelihood of spontaneous resolution. Improved identification of children at risk for recurrent fUTI may impact management decisions, and allow for more individualized VUR management. We have developed and investigated the accuracy of a multivariable computational model to predict probability of breakthrough fUTI in children with primary VUR.

STUDY DESIGN

Children with primary VUR and detailed clinical and voiding cystourethrogram (VCUG) data were identified. Patient demographics, VCUG findings including grade, laterality, and bladder volume at onset of VUR, UTI history, presence of bladder-bowel dysfunction (BBD), and breakthrough fUTI were assessed. The VCUG dataset was randomized into a training set of 288 with a separate representational cross-validation set of 96. Various model types and architectures were investigated using neUROn++, a set of C++ programs.

RESULTS

Two hundred fifty-five children (208 girls, 47 boys) diagnosed with primary VUR at a mean age of 3.1 years (±2.6) met all inclusion criteria. A total 384 VCUGs were analyzed. Median follow-up was 24 months (interquartile range 12-52 months). Sixty-eight children (26.7%) experienced 90 breakthrough fUTI events. Dilating VUR, reflux occurring at low bladder volumes, BBD, and history of multiple infections/fUTI were associated with breakthrough fUTI (Table). A 2-hidden node neural network model had the best fit with a receiver operating characteristic curve area of 0.755 for predicting breakthrough fUTI.

DISCUSSION

The risk of recurrent febrile infections, renal parenchymal scarring, and likelihood of spontaneous resolution, as well as parental preference all influence management of primary VUR. The genesis of UTI is multifactorial, making precise prediction of an individual child's risk of breakthrough fUTI challenging. Demonstrated risk factors for UTI include age, gender, VUR grade, reflux at low bladder volume, BBD, and UTI history. We developed a prognostic calculator using a multivariable model with 76% accuracy that can be deployed for availability on the Internet, allowing input variables to be entered to calculate the odds of an individual child developing a breakthrough fUTI.

CONCLUSIONS

A computational model using multiple variables including bladder volume at onset of VUR provides individualized prediction of children at risk for breakthrough fUTI. A web-based prognostic calculator based on this model will provide a useful tool for assessing personalized risk of breakthrough fUTI in children with primary VUR.

Urinary tract infection in the setting of vesicoureteral reflux

Vesicoureteral reflux (VUR) is the most common underlying etiology responsible for febrile urinary tract infections (UTIs) or pyelonephritis in children. Along with the morbidity of pyelonephritis, long-term sequelae of recurrent renal infections include renal scarring, proteinuria, and hypertension. Treatment is directed toward the prevention of recurrent infection through use of continuous antibiotic prophylaxis during a period of observation for spontaneous resolution or by surgical correction. In children, bowel and bladder dysfunction (BBD) plays a significant role in the occurrence of UTI and the rate of VUR resolution. Effective treatment of BBD leads to higher rates of spontaneous resolution and decreased risk of UTI.

The role of voiding cystourethrography in the investigation of children with urinary tract infections

Urinary tract infections (UTIs) represent a common bacterial cause of febrile illness in children. Of children presenting with a febrile UTI, 25-40% are found to have vesicoureteral reflux (VUR). Historically, the concern regarding VUR was that it could lead to recurrent pyelonephritis, renal scarring, hypertension, and chronic kidney disease. As a result, many children underwent invasive surgical procedures to correct VUR. We now know that many cases of VUR are low-grade and have a high rate of spontaneous resolution. The roles of surveillance, antibiotic prophylaxis, endoscopic injection, and ureteral reimplantation surgery also continue to evolve. In turn, these factors have influenced the investigation of febrile UTIs. Voiding cystourethrography (VCUG) is the radiographic test of choice to diagnose VUR. Due to its invasive nature and questionable benefit in many cases, the American Academy of Pediatrics (AAP) no longer recommends VCUG routinely after an initial febrile UTI. Nevertheless, these guidelines pre-date the landmark Randomized Intervention of Children with Vesicoureteral Reflux (RIVUR) trial and there continues to be controversy regarding the diagnosis and management of VUR. This paper discusses the current literature regarding radiographic testing in children with febrile UTIs and presents a practical risk-based approach for deciding when to obtain a VCUG.

Controversies in the Management of Vesicoureteral Reflux

Vesicoureteral reflux (VUR) is the abnormal retrograde flow of urine from the bladder into the upper urinary tract. Diagnosis and subsequent management of VUR have become increasingly controversial, with differing opinions over which children should be evaluated for reflux, and when detected, who should undergo treatment. Management goals include prevention of recurrent febrile urinary tract infection (fUTI) and renal injury while minimizing the morbidity of treatment and follow-up. Management options include observation with or without continuous antibiotic prophylaxis and surgical correction via endoscopic, open or laparoscopic/robotic approaches. Management should be individualized and based on patient age, health, risk of subsequent renal injury, clinical course, renal function, and parental preference.