What is the risk of urinary tract infection in children with antenatally presenting dilating vesico-ureteric reflux?

Stratifying Antenatal Hydronephrosis: Predicting High-Grade VUR Using Ultrasound and Scintigraphy

(1) Background: Antenatal hydronephrosis (AHN), detected in approximately one percent of prenatal ultrasounds, is caused by vesicoureteral reflux (VUR) in 15-21% of cases, a condition with significant risks such as urinary tract infections and renal scarring. Our study addresses the diagnostic challenges of VUR in AHN. Utilizing renal ultrasonography and scintigraphy, we developed a novel scoring system that accurately predicts high-grade VUR, optimizing diagnostic precision while minimizing the need for more invasive methods like voiding cystourethrogram (VCUG); (2) Methods: This retrospective study re-analyzed renal ultrasonography, scintigraphy, and VCUG images from infants admitted between 2003 and 2013, excluding cases with complex urinary anomalies; (3) Results: Our analysis included 124 patients (75% male), of whom 11% had high-grade VUR. The multivariate analysis identified visible ureter, reduced renal length, and decreased differential renal function (DRF) as primary predictors. Consequently, we established a three-tier risk score, classifying patients into low, intermediate, and high-risk groups for high-grade VUR, with corresponding prevalences of 2.3%, 22.2%, and 75.0%. The scoring system demonstrated 86% sensitivity and 79% specificity; (4) Conclusions: Our scoring system, focusing on objective parameters of the visible ureter, renal length, and DRF, effectively identifies high-grade VUR in AHN patients. This method enhances diagnostics in ANH by reducing reliance on VCUG and facilitating more tailored and less invasive patient care.

The role of circumcision in preventing urinary tract infections in children with antenatal hydronephrosis: Systematic review and meta-analysis

INTRODUCTION

Circumcision has been reported to reduce the risk of urinary tract infections (UTIs) in boys with antenatal hydronephrosis (HN). Our aim was to compare the incidence of UTIs in circumcised vs. uncircumcised boys with antenatal HN by conducting a systematic review and meta-analysis.

STUDY DESIGN

A comprehensive search was performed until December 2022. Comparative studies were evaluated according to Cochrane collaboration recommendations. Assessed measures included: UTIs, continuous antibiotic prophylaxis (CAP) use, renal outcomes, and circumcision complications. Odds ratios (OR) and mean difference with 95% confidence interval (CI) were extrapolated from available data. Random-effects meta-analysis were performed.

RESULTS

Twenty-three studies describing 9093 boys with antenatal HN were identified, including 4677 uncircumcised and 4416 circumcised boys. Overall effect estimates demonstrate that circumcised boys have significantly reduced odds of developing any UTI [OR 0.26, 95%CI 0.21, 0.32; p < 0.001]]. In addition, there a significantly reduced odds of developing UTI when circumcised and on CAP [OR 0.19, 95% CI 0.13, 0.30; p < 0.001]. When stratifying by etiology, circumcision reduced the odds of UTI in boys with isolated HN [OR 0.33, 95% CI 0.16, 0.68; p = 0.003], vesicoureteral reflux [OR 0.23, 95% CI 0.13, 0.42; P < 0.00001], or with posterior urethral valves [OR 0.29, 95% CI 0.13, 0.64; p = 0.002].

DISCUSSION

Circumcision reduces the incidence of UTIs in boys with antenatal HN. This review is limited by the varied definitions of UTIs and inconsistent reporting on HN etiology, renal outcomes, and circumcision complications.

CONCLUSIONS

Circumcision should be considered in boys with antenatal HN to prevent the risk of developing UTI. Further research is warranted to individualize the prophylactic role of circumcision for patients with HN.

Frequency of Urinary Tract Infection When Diagnosing Vesico Uretheral Reflux in Children in Tuzla Canton

Background

Vesicoureteral reflux (VUR) represents the return of urine from the bladder into the ureter and the renal canal system. Reflux can occur only on one or both kidneys. VUR most often occurs due to an incompetent ureterovesical junction, which consequently leads to hydronephrosis and dysfunction of the lower parts of the urinary system.

Objective

The aim of the study was to determine the frequency of urinary infection when diagnosing vesicouretheral reflux in children in the Tuzla Canton, in the five-year period from 01.01.2016 to 01.01.2021.

Methods

Through a retrospective study, we analyzed data from 256 children with vesiocouretheral reflux (VUR), examined in the Nephrology Outpatient Clinic, Clinic for Children's Diseases, University Clinical Center Tuzla, in the period from 01.01.2016 to 01.01.2021, from early neonatal to 15 years of age. The age and gender of children, the most common symptoms of urinary tract infections during the detection of VUR, and the degree of VUR were analyzed.

Results

From 256 children with VUR, 54% were male and 46% female. The highest prevalence of VUR was in the age group 0-2 years, and the lowest in the age of children > 15 years. There was no statistically significant difference between the groups of our respondents in relation to age groups, nor in relation to the gender of the children. Statistically significantly more children were without nonspecific symptoms and with asymptomatic bacteriuria in the group without UTI symptoms in children with VUR compared to the group with UTI symptoms in children with VUR. Pathological urine culture between the groups was without a statistically significant difference.

Conclusion

Although urinary tract infection in children is common, the possibility of permanent consequences should always be kept in mind if VUR is not diagnosed and treated in time.

Circumcision reduces urinary tract infection in children with antenatal hydronephrosis: Systematic review and meta-analysis

INTRODUCTION

Urinary tract infection (UTI) is more prevalent in boys with antenatal hydronephrosis (ANH). Circumcision is known to lessen the risk of UTI. This study was performed to examine the associations between circumcision and UTI among patients with ANH.

METHODS

The Preferred Reporting Items for Systematic Reviews and Meta-Analyses standards were followed for conducting this systematic review and meta-analysis. PubMed, ScienceDirect, EMBASE, and Cochrane Library databases were searched through August 4th, 2022 to identify eligible studies. The risk of bias was measured using the Newcastle-Ottawa Scale (NOS). Review manager 5.4 was used for all analysis.

RESULTS

A total of 21 studies involving 8,968 patients with ANH were included in the meta-analysis. The incidences of UTI were 18.1% in the uncircumcised group and 4.9% in the circumcised group. From analysis, circumcision had significant protective effect against UTI with pooled OR of 0.28 (95% CI 0.23-0.32). The significant protective effects were also found in subgroup analysis of hydronephrosis etiology, including vesicoureteral reflux (pooled OR of 0.24; 95% CI 0.17-0.32), obstructive hydronephrosis (pooled OR of 0.34; 95% CI 0.21-0.53), and posterior urethral valve (pooled OR of 0.28; 95% CI 0.16-0.52).

CONCLUSION

Our meta-analysis showed that circumcision was associated with a decreased incidence of UTI in children with ANH. This benefit was consistent irrespective of the underlying cause of hydronephrosis.

Update of the EAU/ESPU guidelines on urinary tract infections in children

INTRODUCTION/BACKGROUND

Urinary tract infections (UTIs) are common in children and require appropriate diagnostic evaluation, management and follow-up.

OBJECTIVE

To provide a summary of the updated European Association of Urology (EAU) guidelines on Pediatric Urology, which were first published in 2015 in European Urology.

STUDY DESIGN

A structured literature review was performed of new publications between 2015 and 2020 for UTIs in children. The guideline was updated accordingly with relevant new literature.

RESULTS

The occurrence of a UTI can be the first indication of anatomical abnormalities in the urinary tract, especially in patients with a febrile UTI. The basic diagnostic evaluation should include sufficient investigations to exclude urinary tract abnormalities, but should also be as minimally invasive as possible. In recent years, more risk factors have been identified to predict the presence of these anatomical anomalies, such as a non-E. Coli infection, high grade fever and ultrasound abnormalities. When these risk factors are factored into the diagnostic work-up, some invasive investigations can be omitted in a larger group of children. In addition to the treatment of active UTIs, it is also essential to prevent recurrent UTIs and consequent renal scarring. With the increase of antimicrobial resistance good antibiotic stewardship is needed. In addition, alternative preventative measures such as dietary supplements, bladder and bowel management and antibiotic prophylaxis could decrease the incidence of recurrent UTI.

CONCLUSION

This paper is a summary of the updated 2021 EAU guidelines on Pediatric Urology. It provides practical considerations and flowcharts for the management and diagnostic evaluation of UTIs in children.

Management of antenatal hydronephrosis

Antenatal hydronephrosis (AHN) is the most frequently detected abnormality by prenatal ultrasonography. Differential diagnosis of AHN includes a wide variety of congenital abnormalities of the kidney and urinary tract ranging from mild abnormalities such as transient or isolated AHN to more important ones as high-grade congenital vesicoureteral reflux or ureteropelvic junction obstruction. It is well known that the outcome depends on the underlying etiology. Various grading systems have been proposed for the classification of AHN on prenatal and postnatal ultrasonography. Mild isolated AHN represents up to 80% of cases, is considered to be benign, and majority of them resolve, stabilize, or improve during follow-up. Controversies exist regarding the diagnosis and management of some important and severe causes of AHN such as high-grade vesicoureteral reflux and ureteropelvic junction obstruction. Current approach is becoming increasingly conservative during diagnosis and follow-up of these patients with less imaging and close follow-up. However, there is still no consensus regarding the clinical significance, postnatal evaluation, and management of infants with AHN. The aim of this review is to discuss the controversies and provide an overview on the management of AHN.

Antibiotic prophylaxis for prevention of urinary tract infections in the first year of life in children with vesicoureteral reflux diagnosed in the workup of antenatal hydronephrosis: a systematic review

BACKGROUND

Children with antenatal hydronephrosis (ANH) diagnosed with postnatal asymptomatic vesicoureteral reflux (VUR) are thought to be at higher risk of urinary tract infection (UTI). As such, continuous antibiotic prophylaxis (CAP) is empirically recommended until age of toilet training; however, there are limited data to support this. The objective of this systematic review was to summarize the existing data and compare UTI rates in infants with asymptomatic VUR on CAP during the first year of life, to those not on CAP. Secondary objectives were to determine associated risk factors with UTI development.

METHODS

A systematic search of all relevant studies and abstracts was conducted using 4 electronic databases by utilizing appropriate key words by an expert hospital librarian. Eligible studies included children with prenatal hydronephrosis, asymptomatic VUR with or without CAP, and reported on development of UTI in the first year.

RESULTS

Of 6903 citations screened, 18 were selected, giving a total population of 829 (69.4% male, median age 57 days) who met the inclusion criteria. Most studies were retrospective and of low-quality evidence. Overall, 15.4% of patients developed at least one breakthrough UTI and females had a higher risk of UTI (odds ratio (OR) 2.3, 95% CI 1.1-4.7). Comparison with children not taking CAP was not readily reported, and meta-analysis could not be completed.

CONCLUSIONS

Randomized controlled trials and standardized reporting of clinical variables are required to understand the protective effect of antibiotic prophylaxis in this cohort.

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.

Reduced differential renal function in scintigraphy predicted high-grade vesicoureteral reflux in children with antenatal hydronephrosiss

AIM

A top-down approach is widely used for detecting vesicoureteral reflux (VUR) in children with febrile urinary tract infections. We evaluated the diagnostic value of renal scintigraphy in predicting VUR in children with antenatal hydronephrosis (AHN).

METHODS

The voiding cystourethrogram (VCUG) and renal scintigraphy results of 125 AHN patients (76% male) admitted to the Children's Hospital of Helsinki University, Finland, from 2003 to 2013 were analysed. Of those, 94 had nonrefluxing hydronephrosis, nine had low-grade VUR and 22 had high-grade VUR.

RESULTS

Scintigraphy was performed at a median age of 1.4 (0.8-15.6) months. In patients with high-grade VUR, the differential renal function (DRF) of the worse kidney was significantly lower than in patients without VUR, with a median of 35% and interquartile range (IQR) of 20-45 versus 47% (IQR: 44-49), (p < 0.001). There was no difference between patients with low-grade VUR and patients without VUR (p = 0.181). DRFs below 44% showed a sensitivity of 73% and specificity of 79% and predicted significantly high-grade VUR (odds ratio 9.82, 95% confidence interval 3.44-28.05, p < 0.001) in the univariate analysis.

CONCLUSION

A DRF below 44% predicted high-grade VUR in patients with AHN and supported the decision to perform VCUG.

Postnatal imaging of prenatally detected hydronephrosis-when is voiding cystourethrogram necessary?

OBJECTIVE

To evaluate whether grade 4-5 vesicoureteral reflux (VUR) can be predicted from renal ultrasound (RUS) findings and perform voiding cystourethrograms (VCUGs) only on high-risk patients.

METHODS

The RUS and VCUG images of infants with prenatally detected hydronephrosis admitted to our institution between 2003 and 2013 were re-evaluated. The UTI episodes were collected retrospectively from patient journals. Patients with complex urinary tract anomalies were excluded.

RESULTS

One hundred eighty, 44 female and 136 male, patients (352 renal units (RU)), 23 (30 RU) of them having grade 4-5 VUR, were included. The median age of the patients at the time of the RUS was 1.3 (0.1-3.0) months and the median follow-up time was 2.0 (0.1-11.2) years. In multivariate analysis, a visible ureter (OR 12.72; CI 5.33-32.04, p < 0.001) and shorter renal length (OR 2.67; CR 1.50-4.86, p < 0.001) in RUS predicted grade 4-5 VUR while a visible ureter predicted UTIs (OR 5.75; CI 2.59-12.66, p < 0.001). A three-grade risk score for high-grade VUR was developed based on the RUS findings and the patients were categorized into low-, intermediate-, and high-risk groups. The incidence of grade 4-5 VUR was 2.9% in the low-risk, 12.2% in the intermediate-risk, and 52.2% in the high-risk group. The sensitivity and specificity for detecting grade 4-5 VUR were 79 and 82%, respectively.

CONCLUSIONS

In patients with antenatally detected hydronephrosis, a visible ureter and reduced renal length in RUS are significant risk factors for high-grade VUR. A RUS-based risk scoring would probably reduce the proportion of unnecessary VCUGs.

Reflux nephropathy and the risk of preeclampsia and of other adverse pregnancy-related outcomes: a systematic review and meta-analysis of case series and reports in the new millennium

BACKGROUND

Reflux nephropathy is a common urinary tract malformation, and a substantial cause of morbidity in women of childbearing age. While recent studies provide further new information on pregnancy-related outcomes, their results are heterogeneous and a systematic meta-analysis may help the interpretation. The aim of this review was to analyze pregnancy-related outcomes in the recent literature on reflux nephropathy (2000-2016), to perfect the estimation of risks, and to identify specific research needs.

METHODS

We searched Medline, EMBASE and the Cochrane review databases for the period 2000-2016 (PROSPERO registration no. 42016042713).

SELECTION CRITERIA

all case series and case reports dealing with reflux nephropathy and reporting on at least one pregnancy outcome. Data were extracted from eligible case series (≥ 6 cases). For the outcomes preeclampsia (PE), pregnancy-induced hypertension (PIH), preterm birth, and newborns small for gestational age, we employed as a control group the low-risk pregnancies from a multicenter database including 1418 live-born singletons. Case reports were analyzed narratively.

RESULTS

The search retrieved 2507 papers, of which 7 case series and 4 case reports were retained. The series report on 434 women with 879 pregnancies; no study reported controls. Compared to the low-risk controls, the meta-analysis showed an increased risk of PIH (odds ratio, OR 5.55; confidence interval, CI 3.56-8.66), PE (OR 6.04; CI 2.41-15.13), and all hypertensive disorders combined (OR 10.43; CI 6.90-15.75). No difference was observed in preterm delivery and caesarean sections. A higher incidence of stillbirth was reported in one paper. Conversely, the 4 case reports (on 10 pregnancies) alert us to a potentially severe complication, hydro(uretero)nephrosis with or without infection.

CONCLUSION

Reflux nephropathy is associated with an increased risk of PIH and PE, but not of preterm delivery, suggesting the occurrence of late 'maternal' PE. The finding of a higher incidence of stillbirths in one series requires further analysis. Strict follow-up of these women is needed, in particular in late pregnancy stages, to avoid and manage in particular hypertensive pregnancy complications.

Incidence of urinary tract infections in infants with antenatally diagnosed hydronephrosis-A retrospective single center study

OBJECTIVE

To evaluate the incidence of urinary tract infections (UTIs) in infants with antenatal hydronephrosis (AHN).

MATERIALS AND METHODS

A cohort of AHN patients admitted to our institution between 2003 and 2013 were identified. Altogether 192 patients with nonrefluxing hydronephrosis (HN, n=135), nonrefluxing hydroureteronephrosis (HUN, n=21), or vesicoureteral reflux (VUR, n=36) were identified. Patients with complex anomalies or neonatal decompression of the urinary tract were excluded. Information about UTIs diagnosed among the AHN patients was collected and compared with data from 58 controls.

RESULTS

During the median follow-up time of 2.6 (0.3-11.2) years, 24 (13%) patients (15 (10%) males and 9 (19%) females) and 2 (3%) controls experienced at least one UTI (p=0.033). Eighteen (69%) UTIs were febrile. The males had the first UTI at significantly younger age than the females (0.3, 0.0-1.7years vs. 1.0, 0.4-4.8years, p=0.010). UTI was detected in 15 (63%) patients with grade 4-5 VUR, in 8 (6%) patients with HN, and in one (5%) patient with HUN (p-values <0.001, 0.726 and >0.999 against the controls). None of the patients with grade≤3 VUR had UTI. Fifty-eight percent of the patients with UTI were on antimicrobial prophylaxis. In five (12%) cases UTI appeared within one week after voiding cystourethrography (VCUG).

CONCLUSIONS

Infants with AHN and grade 4-5 VUR had the highest risk of UTI. UTIs tented to be more common in females than in males; however, males experienced UTI at younger age than females. VCUG caused UTI in 2.3% in our material.

LEVEL OF EVIDENCE

III.