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

An evaluation of ureteral diameter ratio and vesicoureteral reflux index in the treatment of primary vesicoureteral reflux

Objective

Vesicoureteral reflux (VUR) index is a simple, validated tool that reliably predicts significant improvement and spontaneous resolution of primary reflux in children. The aim of this study was to evaluate and compare the ureter diameter ratio (UDR) and VUR index (VURx) of patients treated with endoscopic injection (EI) and ureteroneocystostomy (UNC) methods in the pediatric age group due to primary VUR.

Methods

Patients under the age of 18 years old who underwent EI and UNC with the diagnosis of primary VUR between January 2011 and September 2021 were determined as the participants. The UDR was assessed using voiding cystourethrography, and the VURx score was determined prior to treatment based on hospital records included in the study.

Results

A total of 255 patients, 60 (23.5%) boys and 195 (76.5%) girls, with a mean age of 76.5 (range 13.0-204.0) months, were included in the study. EI was applied to 130 (51.0%) patients and UNC was applied to 125 (49.0%) patients due to primary VUR. The optimum cut-off for the distal UDR was obtained as 0.17 with sensitivity and specificity of 73.0% and 63.0%, respectively. The positive and negative predictive values were 66.0% and 70.0%, respectively.

Conclusion

When the UDR and VURx score are evaluated together for the surgical treatment of primary VUR in the pediatric age group, it is thought that it may be useful in predicting the clinical course of the disease and evaluating surgical treatment options.

Artificial Intelligence in Pediatric Urology

Application of artificial intelligence (AI) is one of the hottest topics in medicine. Unlike traditional methods that rely heavily on statistical assumptions, machine learning algorithms can identify highly complex patterns from data, allowing robust predictions. There is an abundance of evidence of exponentially increasing pediatric urologic publications using AI methodology in recent years. While these studies show great promise for better understanding of disease and patient care, we should be realistic about the challenges arising from the nature of pediatric urologic conditions and practice, in order to continue to produce high-impact research.

Vesicoureteral Reflux: Current Care Trends and Future Possibilities

Although investigations over the past 2 decades have improved our understanding of the natural history of vesicoureteral reflux (VUR) and helped identify those at higher risk of both VUR itself as well as its potential severe sequelae, debate exists regarding key aspects of care, including when to perform diagnostic imaging and which patients benefit from continuous antibiotic prophylaxis. Artificial intelligence and machine learning have the potential to distill large volumes of granular data into practical tools that clinicians can use to guide diagnosis and management decisions. Surgical treatment, when indicated, remains highly effective and is associated with low morbidity.

A systematic review of the applications of Expert Systems (ES) and machine learning (ML) in clinical urology

BACKGROUND

Testing a hypothesis for 'factors-outcome effect' is a common quest, but standard statistical regression analysis tools are rendered ineffective by data contaminated with too many noisy variables. Expert Systems (ES) can provide an alternative methodology in analysing data to identify variables with the highest correlation to the outcome. By applying their effective machine learning (ML) abilities, significant research time and costs can be saved. The study aims to systematically review the applications of ES in urological research and their methodological models for effective multi-variate analysis. Their domains, development and validity will be identified.

METHODS

The PRISMA methodology was applied to formulate an effective method for data gathering and analysis. This study search included seven most relevant information sources: WEB OF SCIENCE, EMBASE, BIOSIS CITATION INDEX, SCOPUS, PUBMED, Google Scholar and MEDLINE. Eligible articles were included if they applied one of the known ML models for a clear urological research question involving multivariate analysis. Only articles with pertinent research methods in ES models were included. The analysed data included the system model, applications, input/output variables, target user, validation, and outcomes. Both ML models and the variable analysis were comparatively reported for each system.

RESULTS

The search identified n = 1087 articles from all databases and n = 712 were eligible for examination against inclusion criteria. A total of 168 systems were finally included and systematically analysed demonstrating a recent increase in uptake of ES in academic urology in particular artificial neural networks with 31 systems. Most of the systems were applied in urological oncology (prostate cancer = 15, bladder cancer = 13) where diagnostic, prognostic and survival predictor markers were investigated. Due to the heterogeneity of models and their statistical tests, a meta-analysis was not feasible.

CONCLUSION

ES utility offers an effective ML potential and their applications in research have demonstrated a valid model for multi-variate analysis. The complexity of their development can challenge their uptake in urological clinics whilst the limitation of the statistical tools in this domain has created a gap for further research studies. Integration of computer scientists in academic units has promoted the use of ES in clinical urological research.

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.

The additive impact of the distal ureteral diameter ratio in predicting early breakthrough urinary tract infections in children with vesicoureteral reflux

INTRODUCTION

Many factors influence patient and provider decisions to surgically correct vesicoureteral reflux (VUR), including risk of breakthrough febrile urinary tract infections and likelihood of spontaneous resolution. Ureteral diameter ratio has been shown in several studies to be more predictive than reflux grade with regard to breakthrough urinary tract infection (UTI). We developed and investigated the accuracy of a computational model for predicating febrile breakthrough urinary tract infection within 13 months of starting prophylactic antibiotics in children with VUR.

OBJECTIVE

The aim of this study was to validate a model for evaluating the impact of distal ureteral diameter ratio (UDR) in predicting early breakthrough urinary tract infections in children with VUR.

STUDY DESIGN

Following a retrospective review, we recorded patient demographics, presenting symptoms, VUR grade, laterality, VUR during filling or voiding, initial bladder volume at the onset of VUR, ureteral duplication, voiding dysfunction, distal ureteral diameter ratio, and number of UTIs prior to VUR diagnosis. NeUROn++, a set of C++ programs, was used to model each data set using logistic regression and neural networks with different architectures.

RESULTS

After exclusions, 136 children (93 girls and 43 boys) diagnosed with primary VUR had detailed VCUG and UDR data available. Fourteen children (10.3%) experienced breakthrough febrile UTI events within 13 months of VUR diagnosis. There was a significant association with UDR and breakthrough UTI (p = 0.008). Various computational prediction models for the outcome of breakthrough UTI were developed and evaluated. The computational model that fit best was a model using all variables with an ROC of 0.802.

DISCUSSION AND CONCLUSIONS

Clinicians and parents often opt for intervention based on likelihood of spontaneous resolution of VUR as well as clinical course, thereby placing an emphasis on the ability to predict likelihood of breakthrough UTI infections. Our statistical analysis and prediction models further confirm UDR as an important variable predictive of breakthrough UTIs within the first 13 months of beginning prophylactic antibiotics. Furthermore, we developed a neural network model incorporating UDR and grade with an ability to yield the greatest accuracy of any breakthrough UTI predictive calculator to date at 80%.

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.

A scoring system for predicting downgrading and resolution of high-grade infant vesicoureteral reflux

AIM

Aim of the study was to provide a scoring system for predicting downgrading and resolution of infantile high-grade vesicoureteral reflux (VUR).

METHODS

Eighty-nine infants (65 boys) with high-grade VUR (grade 4-5) diagnosed at median age 2.5 months and followed to 39 months had repeated investigations of VUR grade, renal damage/function and bladder function. Recurrent urinary tract infections (UTIs) were registered. Risk variables collected at 1 year were analysed as independent factors for spontaneous resolution to grades ≤2 and 0, using univariable/multivariable logistic regression.

RESULTS

A scoring system was built with a total of 14 points from four independent risk factors (sex, breakthrough UTI, type of renal damage and subnormal glomerular filtration rate). Children with persistent VUR (grade 3-5) had higher scores compared with the group with spontaneous resolution (grade 0-2) (mean 7.9 vs. 4.5, P < .0001). A score of ≥8 points indicated a low probability of VUR resolution (≤14%). The model was considered excellent based on area under the ROC curve (0.82) and showed satisfactory internal validity.

CONCLUSION

This model provides a practical tool in the management of infants born with high-grade reflux. High scores at one year of age indicate a high risk of persistent dilated reflux.

Brazilian consensus on vesicoureteral reflux-recommendations for clinical practice

Introduction

Vesicoureteral Reflux (VUR) is characterized by a retrograde flow of urine from the bladder into the ureters and kidneys. It is one of the most common urinary tract anomalies and the major cause of urinary tract infection (UTI) in the first years of life. If not properly diagnosed and treated can lead to recurrent UTI, renal scar and, in severe cases, to end stage renal disease. Despite recent advances in scientific and technological knowledge, evaluation and treatment of VUR is still controversial and there is still considerable heterogeneity in evaluation methods and therapeutic approaches. The aim of the present consensus is to give a practical orientation on how to evaluate and treat VUR.

Methods

The board of Pediatric Urology of the Brazilian Society of Urology joined a group of experts and reviewed all important issues on Vesicoureteral Reflux evaluation and treatment and elaborated a draft of the document. On November 2017 the panel met to review, discuss and write a consensus document.

Results and Discussion

Vesicoureteral Reflux is a common and challenging problem in children. Children presenting with Vesicoureteral Reflux require careful evaluation and treatment to avoid future urinary tract infections and kidney scars. The panel addressed recommendations on up to date choice of diagnosis evaluation and therapies.

The role of bladder function in the pathogenesis and treatment of urinary tract infections in toilet-trained children

Urinary tract infections (UTIs) are a common reason for referral to pediatric specialists and the risk profile of these children is influenced by age, sex, and underlying urinary tract abnormalities. UTIs in toilet-trained children represent a different entity than confirmed, febrile UTIs that occur in infants, impacted by suboptimal bladder habits, bladder dysfunction, constipation, or a combination of these factors. A comprehensive literature search was conducted using PubMed and MEDLINE and search terms included recurrent UTI, VUR, bladder and bowel dysfunction (BBD), constipation, lower urinary tract symptoms, and voiding dysfunction. Common presenting symptoms of UTI in children include fever (> 38 °C) with or without "traditional" lower urinary tract symptoms (LUTS) such as dysuria, malodorous urine, frequency, urgency, and incontinence. However, many infections in older children are afebrile episodes-consisting primarily of LUTS-which may or may not be confirmed with biochemical and/or microbiological evidence. Therefore, when evaluating toilet-trained children with recurrent UTIs, it is paramount to consider dysfunctional elimination as an underlying cause, diagnose, and treat it prior to indicating surgical options, even in the presence of VUR or other anatomical abnormalities. Although the impact of bladder function on the risk of infections is important, so is the accurate diagnosis and initial evaluation. This review article will focus on an often overlooked yet critical factor: the impact of bladder function, particularly for toilet-trained children, as well as the importance of implementing bladder training strategies, aggressive management of constipation, and pharmacological management as necessary.

Developmental loss, but not pharmacological suppression, of renal carbonic anhydrase 2 results in pyelonephritis susceptibility

Carbonic anhydrase II knockout (Car2^-/-) mice have depleted numbers of renal intercalated cells, which are increasingly recognized to be innate immune effectors. We compared pyelonephritis susceptibility following reciprocal renal transplantations between Car2^-/- and wild-type mice. We examined the effect of pharmacological CA suppression using acetazolamide in an experimental murine model of urinary tract infection. Car2^-/- versus wild-type mice were compared for differences in renal innate immunity. In our transplant scheme, mice lacking CA-II in the kidney had increased pyelonephritis risk. Mice treated with acetazolamide had lower kidney bacterial burdens at 6 h postinfection, which appeared to be due to tubular flow from diuresis because comparable results were obtained when furosemide was substituted for acetazolamide. Isolated Car2^-/- kidney cells enriched for intercalated cells demonstrated altered intercalated cell innate immune gene expression, notably increased calgizzarin and insulin receptor expression. Intercalated cell number and function along with renal tubular flow are determinants of pyelonephritis risk.

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.

Continuous Antibiotic Prophylaxis in Pediatric Urology

Continuous antibiotic prophylaxis (CAP) for urinary tract infection prevention in children with vesicoureteral reflux, hydronephrosis, and hydroureteronephrosis is reviewed. A more selective use of CAP is advocated based on a review of known individual risk factors in each of these conditions that subsequently helps identify the children most likely to benefit from CAP. Both short-term and potential long-term side effects of CAP are reviewed, including the impact of prophylactic antibiotics on bacterial resistance and the microbiome. Alternatives to continuous antibiotic prophylaxis including Vaccinium macrocarpon (Cranberry), probiotics, and vaccines are reviewed.

Critical appraisal of the top-down approach for vesicoureteral reflux

Vesicoureteral reflux (VUR) has been linked to recurrent urinary tract infections (UTIs), renal scarring, hypertension, renal insufficiency and end-stage kidney disease. Different imaging strategies have been proposed to approach children presenting with UTI to sort out patients with significant VUR while minimizing patient morbidity, radiation exposure and financial burden. None of these imaging strategies is universally accepted. The“top-down approach” (TDA) aims at restricting the number of voiding cystourethrograms (VCUGs) and its associated morbidity while identifying patients with clinically-significant reflux. In this approach, children presenting with febrile UTIs are acutely investigated with dimercapto-succinic acid (DMSA) renal scans to identify patients with renal parenchymal inflammation. Those with evidence of renal affection are offered VCUG and late DMSA scan to identify VUR and permanent renal scarring, respectively. Although TDA could identify clinically-significant VUR with high sensitivity, it is not without limitations. The approach segregates patients based on the presence of DMSA cortical lesions omitting the morbidity and the economic burden of UTI. Additionally, some of DMSA lesions are attributed to congenital dysplasia and unrelated to UTI. Ionizing radiation exposure, financial costs, limited availability of DMSA scans in the acute setting, variability in interpreting the results and low yield of actionable findings on DMSA scans are some other limitations. In this review, we tried to address the drawbacks of the TDA and reinforce the value of patient-centered approach for VUR.

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.