Relationship Among Vesicoureteral Reflux, Urinary Tract Infection and Renal Damage in Children

Genetic determinants of renal scarring in children with febrile UTI

BACKGROUND

Febrile urinary tract infections (UTIs) are among the most severe bacterial infections in infants, in which a subset of patients develops complications. Identifying infants at risk of recurrent infections or kidney damage based on clinical signs is challenging. Previous observations suggest that genetic factors influence UTI outcomes and could serve as predictors of disease severity. In this study, we conducted a nationwide survey of infant genotypes to develop a strategy for infection management based on individual genetic risk. Our aims were to identify genetic susceptibility variants for renal scarring (RS) and genetic host factors predisposing to dilating vesicoureteral reflux (VUR) and recurrent UTIs.

METHODS

To assess genetic susceptibility, we collected and analyzed DNA from blood using exome genotyping. Disease-associated genetic variants were identified through bioinformatics analysis, including allelic frequency tests and odds ratio calculations. Kidney involvement was defined using dimercaptosuccinic acid (DMSA) scintigraphy.

RESULTS

In this investigation, a cohort comprising 1087 infants presenting with their first episode of febrile UTI was included. Among this cohort, a subset of 137 infants who underwent DMSA scanning was subjected to gene association analysis. Remarkable genetic distinctions were observed between patients with RS and those exhibiting resolved kidney involvement. Notably, the genetic signature indicative of renal scarring prominently featured mitochondrial genes.

CONCLUSIONS

In this nationwide study of genetic susceptibility to RS after febrile UTIs in infancy, we identified a profile dominated by mitochondrial polymorphisms. This profile can serve as a predictor of future complications, including RS and recurrent UTIs.

Predictors of reflux persistence after endoscopic dextranomer/hyaluronic Acid copolymer injection in pediatric patients with Vesicoureteral reflux: short-term results

This study aims to investigate the factors effective in predicting the persistence of reflux after the first subureteric transurethral injection (STING) of dextranomer/hyaluronic acid copolymer in pediatric patients with vesicoureteral reflux. The data of patients without a previous history of surgery to treat vesicoureteral reflux and who underwent STING for the first time between September 2011 and November 2020 were investigated retrospectively. After considering exclusion criteria, of 199 patients, 127 patients and 180 renal units were suitable for inclusion. A renal unit-based evaluation was made. Age < 61 months (univariate: p = 0.001, multivariate: p = 0.015, HR: 2.352 (1.181-4.686), OR (95% CI)), moderate reflux level (grade 3) (univariate: p < 0.001, multivariate: p = 0.019, HR: 2.703 (1.177-6.209), OR (95% CI)), DRF (differential renal function) < 45 (univariate: p = 0.020, multivariate: p = 0.047, HR: 1.992 (1.009-3.935), OR (95% CI)), and UDR (ureteral diameter ratio) > 0.15 (univariate: p < 0.001, multivariate: p = 0.005, HR: 2.786 (1.368-5.672), OR (95% CI)) were found predictors of reflux persistence after STING surgery both univariate and multivariate analysis. High reflux level (grade 4-5) was statistically significant in univariate analysis (p < 0.001) but not statistically significant in multivariate analysis (p = 0.215). In our study, UDR and DRF were found to be factors affecting reflux persistence. UDR and DRF should be considered in order to predict reflux resolution in patients who will undergo STING.

Parents' experiences of treatment and outcomes in high-grade vesicoureteral reflux in infants - One piece in the puzzle of VUR management?

INTRODUCTION

Countless papers have been published regarding the management and clinical outcome of vesicoureteral reflux (VUR), still no active treatment has been proven superior to another, regarding preserving renal function. When considering comparable treatment alternatives, qualitative research is needed to understand the parents' perspectives and preferences.

OBJECTIVE

This study aims to describe the parents' experiences of infant high-grade VUR (hVUR) regarding continuous antibiotic prophylaxis (CAP), surgical intervention (SI), urinary tract infection (UTI) and renal damage.

MATERIALS AND METHODS

We performed four randomized, semi-structured focus groups (FG) with 19 parents to 15 children (aged 1,5-6 years). All children had been diagnosed with hVUR at <8 months of age and treated with CAP (all groups) and SI (two groups). Discussions were recorded, transcribed and analysed to content. The sample size for the FGs was based on category saturation, which was confirmed through comparison analysis in multiple FGs.

RESULTS

The FGs generated 2,897 parent-reported experiences, of which this study reports on 1,123, sorted into the abovementioned four themes and underlying categories. Negative experiences regarding CAP, such as stress regarding the daily intake and worries about long-term use and side effects, were abundant, whereas positive experiences were few. The experiences regarding SI were negatively affected by inadequate information and postoperative difficulties and positively by empathy, accurate information and adequate preparations. The increased risk of UTIs were described as a constant emotional stress causing restricted social activities, frequent visits to the hospital and challenges regarding urine-sampling. There was a common awareness of renal damage, but few experiences reflected any actual worry.

DISCUSSION

The daily struggle with medications and monitoring for symptoms, concerns of future antibiotic resistance and a parental preference of SI have been documented in previous studies. FG methodology effectively collects data from several participants during the same occasion, the goal being to generate discussions that enable researchers to see the world from the participants' perspective. Since the management of infants with hVUR is still under debate, qualitative research can remind of valuable patient and parent perspectives.

CONCLUSION

This study shows that CAP and the risk of UTI have non-negligible, everyday impact on family life, while renal damage seems of secondary importance. The concerns of surgical treatment are related to an isolated occasion, which can be optimized with proper care and improved preoperative preparations. Awareness of parents' experiences and preferences is helpful when managing children with hVUR.

Risk factors for new renal scarring in children with vesicoureteral reflux receiving continuous antibiotic prophylaxis

To investigate the risk factors for new renal scarring (NRS) in children with vesicoureteral reflux (VUR) receiving continuous antibiotic prophylaxis (CAP). This was a single-center cohort study. The clinical data of 140 children with grade I-V VUR receiving CAP were analyzed. In this study, exposure variables were sex, younger age at the initial diagnosis of UTI ≤ 12 months, the occurrence of breakthrough urinary tract infection (BT-UTI), high-grade VUR, bilateral VUR, etiology, presence of renal scarring at the initial diagnosis and ultrasound abnormalities. The outcome was NRS. A total of 140 children were included in the risk factor analysis of NRS, 73 of whom experienced NRS, an incidence rate of 52.14%. Multivariate Cox regression suggested that the presence of renal function impairment after the initial diagnosis of UTI (OR 3.411, 95% CI 1.5751-6.646) and the occurrence of BT-UTI while receiving CAP (OR 1.995, 95% CI 1.089-2.958) were independent risk factors for NRS. Multivariate Cox regression showed that high-grade VUR had no significant effects on NRS (OR 0.940, 95% CI 0.462-1.912, P = 0.864). No significant difference was identified in multivariate Cox regression analysis in the IV-V group (vs I-III group) (OR 0.960, 95% CI 0.565-1.633, P = 0.960). Renal function impairment after the initial diagnosis of UTI and the occurrence of BT-UTI while receiving CAP were independent risk factors for NRS. Neither univariate analysis nor multivariate analysis found a correlation between VUR grade and NRS.

PIC cystography in occult vesicoureteral reflux: A systematic review highlighting its utility in children with recurrent urinary tract infections and normal VCUG

BACKGROUND

Vesicoureteral reflux (VUR) affects 1-2% of children, predisposing them to pyelonephritis, renal scarring, and reflux nephropathy. Treatment aims to prevent febrile urinary tract infections (f-UTI) and long-term sequelae. While guidelines differ, the current consensus proposes individual risk-stratification and subsequent management strategies. Here, we systematically analyzed the current literature on Positional Instillation of Contrast Cystography (PIC) for individualized diagnostics in patients with recurrent f-UTIs.

OBJECTIVE

We present a comprehensive qualitative and quantitative synthesis. Outcomes were: 1. the ability of PIC to predict VUR in patients with negative voiding cystographies (VCUG), 2. the ability of PIC to predict occult contralateral VUR, 3. the correlation of occult VUR in PIC with dimercaptosuccinic acid (DMSA) scan findings, and 4. the incidence of postoperative f-UTI in children treated for occult VUR picked up on PIC.

STUDY DESIGN

We conducted a systematic review following the PRISMA guidelines, applying the following inclusion criteria: Children with occult VUR in PIC with negative VCUG.

RESULTS

We included nine studies with 496 symptomatic patients with a mean age of 6.8 years, published between 2003 and 2021. PIC detected VUR in 73% of patients. Out of them, 81% had low-grade and 19% high-grade VUR. Occult contralateral VUR was present in 41% children. The presence of renal scars on DMSA scan was 1.39 times more likely with occult VUR on PIC. 85% of patients did not experience recurrent f-UTIs after PIC and subsequent treatment.

DISCUSSION

PIC can detect occult VUR in patients with recurrent f-UTIs in whom VCUG is negative. However, we recommend a cautious approach in the use of PIC in clinical practice until further prospective studies confirm the validity of our outcome measures.

CONCLUSION

Identification, risk stratification, and prompt action are central in managing VUR. PIC can be helpful in identifying VUR in patients with recurrent f-UTI.

How the 99mTc-DMSA scintigraphy findings are reflected in the adopted treatment of primary vesicoureteral reflux: One centre experience

BACKGROUND

Renal changes may have long-term sequalae and prevention is a main goal of management of primary vesicoureteral reflux (VUR).

AIM

This study aims to reveal how much ^99mTc-DMSA scintigraphy findings are reflected in the adopted surgical or non-surgical treatment in children with diagnosed primary VUR and to give the clinicians information regarding their final therapeutic decision.

PATIENTS AND METHODS

A total 207 children with primary VUR who underwent non-acute ^99mTc-DMSA scan were retrospectively evaluated. The presence of renal changes, their grading, differential function asymmetry (<45%) and grade of VUR were compared with subsequent choice of therapy.

RESULTS

Altogether 92 (44%) children had asymmetric differential function, 122 (59%) showed presence of renal changes, 79 (38%) had high-grade VUR (IV-V). Patients with renal changes had lower differential function (41%vs.48%) and higher grade of VUR. The incidence of high-grade changes (G3+G4B) afflicting more than one third of the kidney was significantly different between grade I-II, III and IV-V VUR (9%, 27%, 48%, respectively). Renal changes were detected in 76% of surgically and 48% of non-surgically treated patients, high-grade ^99mTc-DMSA changes in 69% and 31%, respectively. In children with no scars/dysplasia (G0+G4A), non-surgical treatment prevailed in 77%. The independent predictors for surgical intervention were presence of renal changes and higher grade of VUR, but not functional asymmetry.

DISCUSSION

Over the last 20 years, there has been a shift toward more non-surgical management of VUR. The long-term outcome of this approach should be thoroughly studied. This is the first study analysing renal status in VUR patients using ^99mTc-DMSA scan and its grading regarding the adopted treatment. Renal changes in almost half of non-surgically treated children with VUR should be an indicator for earlier diagnosis and effective treatment of acute pyelonephritis and VUR. We recommend distinguishing grade III VUR, as a moderate-grade VUR, because it is linked to higher incidence of high-grade ^99mTc-DMSA changes (G3+G4B); our findings of 65% of grade III VURs treated non-surgically should be cautionary. Grade III VUR does not mean a low-risk condition and should alert the clinician to evaluate the extent of renal changes and unmask high-risk cases.

CONCLUSIONS

Our data strengthens the need to investigate the extent of renal changes in VUR patients regarding treatment decision. Performing ^99mTc-DMSA scan individualizes the treatment of VUR patients; its grading can distinguish grade III-VUR as a separate risk entity because it differs significantly in terms of incidence of high-grade renal changes and chosen therapy.

Is technetium-99m dimercaptosuccinic acid renal scintigraphy available for predicting vesicoureteral reflux in children with first febrile urinary tract infection under the age of 24 months?

OBJECTIVE

Vesicoureteral reflux (VUR) is a common complication after urinary tract infection (UTI) and can lead to irreversible renal scar. Voiding cystourethrogram is the most reliable technology to detect VUR and its severity, but it is restricted in children's examinations for various shortcomings. This study aimed to evaluate and compare the efficiency of Tc-99m DMSA renal scintigraphy and conventional ultrasonography (USG) in predicting VUR with the gold standard of cystourethrogram results.

METHODS

This retrospective study consisted of 285 first febrile UTI children under the age of 24 months who completed inflammatory indicator examinations, USG, Tc-99m DMSA renal scintigraphy and underwent cystourethrography after controlling infection with prophylactic antibiotics. The efficiency of Tc-99m DMSA renal scintigraphy and USG in predicting VUR was calculated and compared.

RESULTS

Abnormal USG (40.23% vs. 21.72%, P = 0.001) and Tc-99m DMSA renal scintigraphy results (87.36% vs. 71.72%, P = 0.004) were more common in VUR children. The sensitivity of USG in predicting VUR was only 40.23%, whereas the sensitivity and negative predictive value of Tc-99m DMSA renal scintigraphy reached 87.63 and 83.58%, respectively. Tc-99m DMSA renal scintigraphy had a higher efficacy than USG in predicting high-grade reflux kidneys (73.87% vs. 33.33%; P < 0.001), but there was no significant difference in predicting low-grade reflux kidneys ( P = 0.703).

CONCLUSION

Tc-99m DMSA renal scintigraphy had a significant higher efficiency in predicting VUR (a common cause of renal scarring, detected on DMSA) in first febrile urinary tract infection children under the age of 24 months as compared with USG, especially in high-grade reflux.

Risk factors for breakthrough urinary tract infection in children with vesicoureteral reflux receiving continuous antibiotic prophylaxis

BACKGROUND

To investigate the risk factors for breakthrough urinary tract infection (BT-UTI) in children with vesicoureteral reflux (VUR) receiving continuous antibiotic prophylaxis (CAP).

METHODS

This was a single-centre cohort study (January 2016 to December 2019). The clinical data of 256 children with grade I-V VUR receiving CAP were analysed. In this study, exposure variables were sex, younger age at the initial diagnosis of UTI ≤12 months, high-grade VUR, bilateral VUR, aetiology, presence of renal scarring at the initial diagnosis, presence of renal function impairment at the initial diagnosis, ultrasound abnormalities, antibiotic used and bladder and bowel dysfunction (BBD). Outcome was BT-UTI.

RESULTS

BT-UTI occurred in 81 out of 256 children with grade I-V VUR who received CAP, an incidence of 31.64%. Univariate analysis showed that younger age at the initial diagnosis of UTI (≤12 months), bilateral VUR, renal scarring on the dimercaptosuccinic acid (DMSA) scan at the initial diagnosis of UTI and BBD were correlated with the occurrence of BT-UTI. Multivariate analysis showed that younger age at the initial diagnosis of UTI (≤12 months) [hazard ratio (HR): 4.629; 95% confidence interval (CI): 1.302-16.462], bilateral VUR (HR: 2.078; 95% CI: 1.084-4.022) and BBD (HR: 3.194; 95% CI: 1.243-8.206) were independent risk factors for the occurrence of BT-UTI.

CONCLUSIONS

For VUR children receiving CAP, younger age at the initial diagnosis of UTI (≤12 months), bilateral VUR, and BBD were independent risk factors for the occurrence of BT-UTI.

Analysis of Indications for Voiding Cystography in Children

In this study, we report the experience of our center with the prognosis of vesicoureteral reflux, depending on the indications for voiding cystography, during a 12-year period. Retrospective analysis included 4302 children who were analyzed according to the indication for voiding cystography: (1) a febrile urinary tract infection, (2) urinary tract malformations on ultrasonography and (3) lower urinary tract dysfunction. Vesicoureteral reflux was found in 917 patients (21.32%; 24.1% of girls and 17.9% of boys). In group (1), reflux was found in 437/1849 cases (23.63%), group (2) in 324/1388 cases (23.34%) and group (3) in 156/1065 cases (14.65%). A significantly lower prevalence of reflux and its lower degree was found in children from group (3) when compared to other groups (p < 0.01). VURs were confirmed in over 20% of children with urinary tract malformations on ultrasonography or after a febrile urinary tract infection, suggesting the need for voiding cystography in these children. Indications for this examination in children with lower urinary tract dysfunction should be limited.

Clinical and Epidemiological Analysis of Children's Urinary Tract Infections in Accordance with Antibiotic Resistance Patterns of Pathogens

The study was conducted to analyze urinary tract infections (UTI) in children by considering epidemiology and antibiotic resistance patterns of pathogens in accordance with inflammatory parameters. The research included 525 patients who demonstrated 627 episodes of UTI. The increasing resistance of bacteria was observed over the years covered by the study (p < 0.001). There was a significant increase of resistance to amoxicillin with clavulanic acid (p = 0.001), gentamicin (p = 0.017) and ceftazidime (p = 0.0005). According to the CART method, we managed to estimate C-reactive protein (CRP), procalcitonin (PCT) and white blood cell (WBC) values, in which antibiotic sensitivity was observed. In children with CRP > 97.91 mg/L, there was a high percentage of sensitive cases to amoxicillin with clavulanic acid (87.5%). Values of WBC above 14.45 K/µL were associated with E. coli more sensitivity to ampicillin. 100% of children with CRP > 0.42 mg/L and PCT ≤ 6.92 ng/mL had confirmed sensitivity to cefuroxime. Concerning sensitivity to gentamicin, the most optimal cut-off point of WBC was >7.80 K/µL, while in the case of nitrofurantoin, it was CRP value > 0.11 mg/L (which was presented in 98.50% of children). These results may guide us with antibiotic therapy and help to inhibit increasing antibiotic resistance.

X-ray videocystometry for high-speed monitoring of urinary tract function in mice

Lower urinary tract dysfunction (LUTd) represents a major health care problem with a high, unmet medical need. Design of additional therapies for LUTd requires precise tools to study bladder storage and voiding (dys)function in animal models. We developed videocystometry in mice, combining intravesical pressure measurements with high-speed fluoroscopy of the urinary tract. Videocystometry substantially outperforms current state-of-the-art methods to monitor the urine storage and voiding process, by enabling quantitative analysis of voiding efficiency, urethral flow, vesicoureteral reflux, and the relation between intravesical pressure and flow, in both anesthetized and awake, nonrestrained mice. Using videocystometry, we identified localized bladder wall micromotions correlated with different states of the filling/voiding cycle, revealed an acute effect of TRPV1 channel activation on voiding efficiency, and pinpointed the effects of urethane anesthesia on urine storage and urethral flow. Videocystometry has broad applications, ranging from the elucidation of molecular mechanisms of bladder control to drug development for LUTd.

How Swedish guidelines on urinary tract infections in children compare to Canadian, American and European guidelines

Urinary tract infections (UTI) are common in children and the guidelines focus on preventing kidney damage. We compared the 2013 national Swedish guidelines on UTIs in children with the guidelines from America, Canada, UK, Spain, Italy and European urologists. This showed that urinalysis and urine cultures are endorsed by all the guidelines, but sampling techniques and bacteria levels differ. They all recommend initial oral treatment and renal ultrasound to detect major anomalies in infants. The Swedish guidelines are more liberal on antibiotic prophylaxis.

Conclusion

Differences in diagnostic criteria, workup and accepted methods for urine sampling were noted and are discussed.

Effectiveness and risks of endoscopic management compared to vesicoureteral reimplantation in patients with high-grade vesicoureteral reflux: systematic review and network meta-analysis

The purpose of this study is to determine the effectiveness and safety of endoscopic management compared to ureterovesical reimplantation in pediatric patients with high-grade vesicoureteral reflux in terms of urinary tract infection. We performed a network meta-analysis. We searched in MEDLINE, EMBASE, LILACS, and CENTRAL. We included clinical experiments, quasi-experiments, and cohorts studies. The population was men and women between 1 month and 15 years old. Patients had primary high-grade VUR diagnosed by voiding cystourethrography. The interventions were subureteric bulking agent endoscopic injection (polytetrafluoroethylene, hyaluronic acid, collagen, Dx/Ha, and PPC) vs vesicoureteral reimplantation (Cohen, Politano-Leadbetter, Glenn-Anderson, and Lich-Gregoir), and the primary outcome was urinary infections. Nine studies accomplished the inclusion criteria (seven observational and two clinical experiments). A total of 1448 renal units underwent surgical treatments for the correction of high-grade VUR. Regarding the primary outcome, we compared Dx/Ha with Cohen, Lich-Gregoir, and PPC, finding an RD of -0.02 (95%CI -0.09 to 0.06), RD of -0.02 (95%CI -0.10 to 0.07), and an RD of -0.03 (- 0.13 to 0.07), respectively.Conclusion: Our study showed that there were no differences in UTI episodes after VUR correction in patients undergoing endoscopic management compared with vesicoureteral reimplantation. What is Known: • Primary vesicoureteral reflux is one of the most common congenital anomalies of the urinary tract. • The clinical practice guidelines recommend the surgical management of patients with high-grade VUR. What is New: • There were no differences in UTI episodes after VUR correction in patients undergoing endoscopic management compared with vesicoureteral reimplantation.

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.

The Change in the Renal Pelvis Anterior-Posterior Diameter Between Prevoiding and Postvoiding Status, and Its Correlation With Vesicoureteral Reflux

In this study, our aim was to evaluate the significance of the change in renal pelvis anterior-posterior diameter (RPAPD) before and after micturition between vesicoureteral reflux (VUR)-positive and -negative patients to whom had voiding cystourethrography (VCUG) was performed.In this study, 69 children, age ranging from 0 to 12 years, were included. Before the VCUG imaging, the RPAPD was measured first with a full bladder and then after urination via ultrasound (US). The differences between in RPAPD measurements were noted and values compared made among VUR-positive and -negative children. Data distribution was inhomogeneous, and the Wilcoxon Sign Rank test was utilized instead of Student t test. There was no statistically significant difference in prevoiding and postvoiding RPAPD in VUR (+) and VUR (-) patients (P = 0.672). There was no statistically significant relation between VUR and the presence of hydronephrosis (P = 0.126). Vesicoureteral reflux is more common in patients with urinary tract infections (UTI) (P = 0.001). There was no statistically significant relationship between prevoiding and postvoiding RPAPD change and VUR diagnosis (P = 0,164).Ultrasound is the modality of choice for urinary system evaluation. Diagnosis of hydronephrosis via US is not sufficient in predicting VUR; however, indirect findings may reveal the diagnosis. A decrease in RPAPD in postvoiding US evaluation may not rule out the VUR diagnosis for this reason further imaging modalities, such as VCUG, should be taken into consideration for the patients with clinical suspicion.

The risk factors for recurrence of febrile urinary tract infection and renal scarring in children with functional urinary incontinence

OBJECTIVES

Functional urinary incontinence is often associated with recurrent urinary tract infection (UTI), vesicoureteral reflux (VUR), and renal scarring. This study aims to evaluate the correlations between urodynamic findings and recurrence of UTI, VUR, and renal scarring in children with functional incontinence.

METHODS

In this retrospective observational study, data on the presence of VUR, urodynamics and 99Tc-dimercaptosuccinic acid scintigraphy findings, and episodes of febrile UTI were obtained from patients' records. The patients had at least 3 years of follow-up.

RESULTS

There were significant associations between recurrence of UTI and decreased bladder capacity (hazard ratio: 1.321, P = .028). The receiver operator characteristic curve analysis showed a cutoff value for compliance of 13.25 mL/cmH₂ O for renal scarring (P = .000). There was a significant association between bladder wall thickening and VUR (odds ratio: 2.311, P = .008). The compliance had a cutoff value of 14.7 mL/cm H₂ O (P = .023) for severe VUR. The frequency of renal scarring was higher in patients with severe VUR and dysfunctional voiding (P = .001 and P = .041, respectively). The independent risk factors for renal scarring were low compliance, severe VUR, and dysfunctional voiding in children with functional incontinence, but recurrence of febrile UTI was not a risk factor for renal scarring. Decreased bladder capacity was a risk factor for recurrence of febrile UTI.

CONCLUSIONS

The present study suggests that low compliance, severe VUR, and dysfunctional voiding, but not the recurrence of febrile UTI, are the independent risk factors for renal scarring in children with functional incontinence, and decreased bladder capacity is the risk factor for the recurrence of febrile UTI.

Procalcitonin, C-reactive protein, and erythrocyte sedimentation rate for the diagnosis of acute pyelonephritis in children

BACKGROUND

In children with urinary tract infection (UTI), only those with pyelonephritis (and not cystitis) are at risk for developing long-term renal sequelae. If non-invasive biomarkers could accurately differentiate children with cystitis from children with pyelonephritis, treatment and follow-up could potentially be individualized. This is an update of a review first published in 2015.

OBJECTIVES

The objectives of this review were to 1) determine whether procalcitonin (PCT), C-reactive protein (CRP), erythrocyte sedimentation rate (ESR) can replace the acute DMSA scan in the diagnostic evaluation of children with UTI; 2) assess the influence of patient and study characteristics on the diagnostic accuracy of these tests, and 3) compare the performance of the three tests to each other.

SEARCH METHODS

We searched MEDLINE, EMBASE, DARE, Web of Science, and BIOSIS Previews through to 17th December 2019 for this review. The reference lists of all included articles and relevant systematic reviews were searched to identify additional studies not found through the electronic search.

SELECTION CRITERIA

We only considered published studies that evaluated the results of an index test (PCT, CRP, ESR) against the results of an acute-phase ⁹⁹Tc-dimercaptosuccinic acid (DMSA) scan (conducted within 30 days of the UTI) in children aged 0 to 18 years with a culture-confirmed episode of UTI. The following cut-off values were used for the primary analysis: 0.5 ng/mL for procalcitonin, 20 mg/L for CRP and 30 mm/hour for ESR.

DATA COLLECTION AND ANALYSIS

Two authors independently applied the selection criteria to all citations and independently abstracted data. We used the bivariate model to calculate pooled random-effects pooled sensitivity and specificity values.

MAIN RESULTS

A total of 36 studies met our inclusion criteria. Twenty-five studies provided data for the primary analysis: 12 studies (1000 children) included data on PCT, 16 studies (1895 children) included data on CRP, and eight studies (1910 children) included data on ESR (some studies had data on more than one test). The summary sensitivity estimates (95% CI) for the PCT, CRP, ESR tests at the aforementioned cut-offs were 0.81 (0.67 to 0.90), 0.93 (0.86 to 0.96), and 0.83 (0.71 to 0.91), respectively. The summary specificity values for PCT, CRP, and ESR tests at these cut-offs were 0.76 (0.66 to 0.84), 0.37 (0.24 to 0.53), and 0.57 (0.41 to 0.72), respectively.

AUTHORS' CONCLUSIONS

The ESR test does not appear to be sufficiently accurate to be helpful in differentiating children with cystitis from children with pyelonephritis. A low CRP value (< 20 mg/L) appears to be somewhat useful in ruling out pyelonephritis (decreasing the probability of pyelonephritis to < 20%), but unexplained heterogeneity in the data prevents us from making recommendations at this time. The procalcitonin test seems better suited for ruling in pyelonephritis, but the limited number of studies and the marked heterogeneity between studies prevents us from reaching definitive conclusions. Thus, at present, we do not find any compelling evidence to recommend the routine use of any of these tests in clinical practice.

Vesicoureteral Reflux in Adults with Urinary Tract Infections: Is There a Role for Treatment?

PURPOSE OF REVIEW

Urinary tract infections (UTI) place a significant burden on individual patients and the healthcare system as a whole. Vesicoureteral reflux (VUR) is a risk factor for UTIs and is the focus of much research in the pediatric field due to the opportunity for early intervention and prevention of long-term sequelae. However, VUR in the adult population is not well studied and can present different treatment challenges. The goal of this review article is to discuss the role VUR plays in UTIs in the adult population with a specific focus on complications and treatment.

RECENT FINDINGS

The true prevalence of VUR in the adult population remains unknown, and urologists need to maintain an index of suspicion for VUR when evaluating adult patients with recurrent pyelonephritis or complicated UTIs. A number of case series and smaller retrospective studies have documented successful endoscopic treatment of adult VUR patients with recurrent pyelonephritis. Ureteral reimplantation remains an option for adult patients who are refractory to endoscopic treatment of VUR. The current treatments and recommendations for VUR in adults have been extrapolated from the pediatric population due to the scarcity of research. VUR is uncommon in the adult population and requires a high index of suspicion by the clinician. Accurate diagnosis and treatment of VUR can relieve patients from recurrent infections, repetitive antibiotic use, and the risk of hospitalization.

Guidelines for the medical management of pediatric vesicoureteral reflux

Urinary tract infection is a bacterial infection that commonly occurs in children. Vesicoureteral reflux is a major underlying precursor condition of urinary tract infection, and an important disorder in the field of pediatric urology. Vesicoureteral reflux is sometimes diagnosed postnatally in infants with fetal hydronephrosis diagnosed antenatally. Opinions vary regarding the diagnosis and treatment of vesicoureteral reflux, and diagnostic procedures remain debatable. In terms of medical interventions, options include either follow‐up observation in the hope of possible spontaneous resolution of vesicoureteral reflux with growth/development or provision of continuous antibiotic prophylaxis based on patient characteristics (age, presence/absence of febrile urinary tract infection, lower urinary tract dysfunction and constipation). Furthermore, there are various surgical procedures with different indications and rationales. These guidelines, formulated and issued by the Japanese Society of Pediatric Urology to assist medical management of pediatric vesicoureteral reflux, cover the following: epidemiology, clinical practice algorithm for vesicoureteral reflux, syndromes (dysuria with vesicoureteral reflux, and bladder and rectal dysfunction with vesicoureteral reflux), diagnosis, treatment (medical and surgical), secondary vesicoureteral reflux, long‐term prognosis and reflux nephropathy. They also provide the definition of bladder and bowel dysfunction, previously unavailable despite their close association with vesicoureteral reflux, and show the usefulness of diagnostic tests, continuous antibiotic prophylaxis and surgical intervention using site markings.

Predictive factors for bacteremia in febrile infants with urinary tract infection

This study aimed to investigate the predictive factors of concomitant bacteremia occurring in febrile infants who initially presented with pyuria and fever, and were subsequently diagnosed with culture-proven urinary tract infection (UTI). We conducted a retrospective cohort study for January 2010–October 2018 that included infants younger than six months with febrile UTI at a tertiary hospital. The study included 463 patients, of whom 34 had a concomitant bacteremic UTI. Compared to those in the non-bacteremic urinary tract infection (UTI) group, the bacteremic UTI group had a lower mean age; higher levels of C-reactive protein (CRP), delta neutrophil index (DNI, reflects the fraction of immature granulocytes) and blood urea nitrogen (BUN); lower levels of hemoglobin (Hb) and albumin; and a lower platelet count. Vesicoureteral reflux (VUR) was detected nearly twice as often in patients with bacteremic UTI compared to those with non-bacteremic UTI (59.3% vs. 30.6%; P = 0.003). Univariate logistic analyses showed that age ≤90 days; higher DNI, CRP, and creatinine levels; lower Hb and albumin levels; and the presence of VUR were predictors for bacteremic UTI. On multivariate logistic regression analysis, age ≤90 days, higher DNI and CRP levels, and the presence of VUR were independent predictors of bacteremic UTI. The area under the receiver operating characteristic curve of the multivariate model was 0.859 (95% CI, 0.779–0.939; P < 0.001). Age ≤90 days, higher DNI and CRP values may help predict bacteremia of febrile infants younger than 6 months with UTI. Vesicoureteral reflux imaging is also recommended in infants with bacteremic UTI to evaluate VUR.

The long-term prognosis of nephropathy in operated reflux

OBJECTIVE

To investigate the postoperative long-term prognosis and the factors predicting the renal function of patients with reflux nephropathy. As the serum creatinine (s-Cr) level tends to increase during infancy, the degree of reflux and renal parenchymal damage are thought to be more important factors in pediatric patients than in older patients.

MATERIALS AND METHODS

This study examined s-Cr, urinary protein, and blood pressure of patients who underwent anti-reflux surgery 10 years before. It also calculated the postoperative estimated glomerular filtration rate (eGFR) and examined the correlation between the eGFR and preoperative factors (age, gender, number of urinary tract infections [UTIs], primary diagnosis, reflux grade, percentage of dimercaptosuccinic acid uptake, degree of renal parenchymal damage, s-Cr abnormality, proteinuria, and hypertension), and analyzed the factors associated with the long-term prognosis.

RESULTS

The study population was 51 infants (37 boys and 14 girls). The mean age of the patients before surgery and at the follow-up examination was 3.41 ± 3.61 and 14.63 ± 3.74 years, respectively. After surgery, the s-Cr, urinary protein, and blood pressure values showed (44.7%, 26.7%, and 18.2%, respectively) were abnormal. The postoperative eGFR was a mean 90.27 ± 20.42 ml/min/1.73 m² and primary correlated with an older age (P = 0.0361), no UTI at the primary diagnosis (P = 0.0044), reflux grade ≥8 (P = 0.0180), degree of renal parenchymal damage (group ≥2b, P < 0.0001), s-Cr abnormality (P < 0.0001), and proteinuria (P = 0.0001) at baseline. A total of 20 patients had chronic kidney disease (CKD; Fig. 1). The multiple regression analysis of these factors revealed that an older age (P = 0.0021), reflux grade ≥8 (P = 0.0134), and degree of renal parenchymal damage (group ≥2b, P < 0.0001) were significantly associated with the long-term postoperative prognosis of reflux nephropathy. Using these three factors, this study derived a multiple regression equation estimating eGFR in the 10th year after surgery (Fig. 1).

DISCUSSION

In this study, severe vesico-ureteral reflux (reflux grade ≥8) and severe renal parenchymal damage (group ≥2b) were associated with a long-term decrease in the eGFR. In particular, renal parenchymal damage was closely correlated with the postoperative eGFR; thus, this was clearly a critical factor. The age at surgery showed a better correlation with the postoperative eGFR in the multiple regression analysis; thus, age was regarded as an independent prognostic factor.

CONCLUSIONS

The age, reflux grade, and degree of renal parenchymal damage at baseline were factors that affected the long-term postoperative prognosis of reflux nephropathy. Patients with high-grade reflux and severe renal parenchymal damage were more likely to show a reduced CKD level at 10 years after anti-reflux surgery.

Predictors of Renal Dysfunction in Adults with Childhood Vesicoureteral Reflux after Long-Term Follow-Up

BACKGROUND:

Triad of childhood vesicoureteral reflux (VUR), urinary infection (UTI) and renal scarring might initiate potentially serious consequences that lead to renal dysfunction manifested at the second or third decade of life.

AIM:

To identify the risk factors predictive for renal dysfunction in adults with primary VUR after long-term follow-up.

METHODS:

We evaluated the records of 101 children (94.1% female, 5.9% male) at a median age of 5.2 ± 2.3 years (1-12 years), suffering from UTI and VUR. The patients were interviewed after mean 21 years from the first episodes of VUR (8 to 32 years). Renal function was determined from the estimated glomerular filtration rate (eGFR).

RESULTS:

Renal scarring was detected in 68.3% out of 82 patients and bilateral one in 7.3% patients. Linear regression analysis revealed that presence of proteinuria (B = -33.7, p=0.0001), the greater number of years from VUR diagnosis (B = -1.6, p = 0.002) and renal scarring (B = -14.8, p = 0.005) appeared as independent predictors of reduced global eGFRcreat. The same variables plus microalbuminuria (B = -1.0, p = 0.012) appeared as independent predictors of reduced global eGFRcreat-cys. Bilateral scarring (OR=25.5, p = 0.003) appeared as independent predictor of greater risk for CKD assessed using eGFRcreat while greater number of years from VUR diagnosis (OR = 1.7, p = 0.092), microalbuminuria (OR = 1.3, p = 0.047) and again bilateral scarring (OR = 31.3, p = 0.040) appeared as predictors of risk for CKD assessed using eGFRcreat-cys.

CONCLUSION:

Identification of those with an increased risk of progression to CKD should be the goal in all patients with childhood VUR. Their systematic follow-up should be till adulthood and older age.

Prediction of vesicoureteral reflux in children with febrile urinary tract infection using relative uptake and cortical defect in DMSA scan

BACKGROUND

Vesicoureteral reflux (VUR) is an important urologic anomaly that causes renal injury in children with febrile urinary tract infection (UTI). The present study aimed to evaluate the associations of abnormalities detected on technetium-99m-labeled dimercaptosuccinic acid (DMSA) scans, focusing on the association with VUR of the levels of relative decrease in kidney function and cortical defects after a first febrile UTI in children.

METHODS

All 171 children underwent ultrasonography, DMSA scan and voiding cystourethrography (VCUG). The features of ultrasound and DMSA scans were compared between patients with (n = 48) and without VUR (n = 123). The relative uptake (RU) by each kidney was derived from the absolute value of the differences between the value for RU of radionuclide in the right kidney and that in the left kidney. The extent of cortical defects (ECD) was graded according to the number of compartments that contained cortical defect in both kidneys (right upper/right lower, left upper/left lower). Receiver operating characteristic curves were constructed to examine the diagnostic value of these parameters of ultrasound and DMSA scans for predicting VUR.

RESULTS

The ratio of patients having hydronephrosis on ultrasound or cortical defects on DMSA scan did not differ significantly between VUR and non-VUR groups. However, the absolute values of the RU and the scores for ECD were significantly higher in the VUR group than in the non-VUR group. The area under the curves for these two parameters were higher than those for the presence of hydronephrosis or the presence of cortical defects or both.

CONCLUSION

Decreased relative function and increased extents of cortical defects on DMSA scan may be associated with the presence of VUR. These findings may assist pediatricians to decide whether febrile UTI children need to undergo VCUG.

Endoscopic Injection of Dextranomer/Hyaluronic Acid as First Line Treatment in 851 Consecutive Children with High Grade Vesicoureteral Reflux: Efficacy and Long-Term Results

PURPOSE

Endoscopic injection of dextranomer/hyaluronic acid is widely acknowledged as first line treatment of lower grade vesicoureteral reflux. We demonstrate its long-term efficacy and safety in eradicating high grade reflux.

MATERIALS AND METHODS

A total of 518 girls and 333 boys with a median age of 2.3 years (range 2 months to 13.7 years) underwent endoscopic correction of high grade vesicoureteral reflux using dextranomer/hyaluronic acid. Reflux was unilateral in 415 cases and bilateral in 436, comprising 1,287 refluxing units. Reflux was grade IV in 1,153 ureters (89.6%) and grade V in 134 (10.4%). ^99mTechnetium-dimercaptosuccinic acid scintigraphy identified renal scarring in 317 patients (37.3%). Followup ultrasound and voiding cystourethrogram were performed 3 months after intervention and renal ultrasound yearly thereafter. Median followup was 8.5 years (range 6 months to 16 years).

RESULTS

Overall resolution rate after the first endoscopic injection was 69.5% (895 of 1,287 cases), with resolution in 70.4% of grade IV and 61.9% of grade V cases. Reflux resolved after a second injection in 259 cases (20.1%) and after a third injection in 133 (10.4%). Persistent reflux after initial treatment was significantly more common in patients younger than age 1 year and in individuals with renal scarring. No significant postoperative complications were observed and no patient required ureteral reimplantation. Following reflux resolution febrile urinary tract infection developed in 43 children (5.1%), including 24 (55.8%) during the first year, 15 (34.9%) during the second year and 4 (9.3%) during year 3 or later. Of these patients 6 had reflux recurrence and 8 had neocontralateral grade III reflux, which was successfully treated with a single endoscopic injection of dextranomer/hyaluronic acid.

CONCLUSIONS

Endoscopic injection of dextranomer/hyaluronic acid is an efficient and safe long-term treatment for grade IV and V vesicoureteral reflux, and can easily be repeated in patients with treatment failure with a high subsequent resolution rate.

A Reanalysis of the RIVUR Trial Using a Risk Classification System

PURPOSE

The RIVUR (Randomized Intervention for Children with Vesicoureteral Reflux) trial showed a 50% decrease in the risk of urinary tract infection recurrence in children with reflux receiving continuous antibiotic prophylaxis. We reanalyzed the RIVUR data with the purpose of using a risk classification system to identify children who are more likely to benefit from continuous antibiotic prophylaxis.

MATERIALS AND METHODS

Data from 607 children enrolled in the RIVUR trial were obtained from the National Institute of Diabetes and Digestive and Kidney Diseases Central Repository and analyzed. We stratified these children into low and high risk categories. The proportion of children and risk of urinary tract infection recurrence in the stratified treatment groups were compared.

RESULTS

Of the children 385 (63.9%) were stratified into the low risk and 217 (36.1%) into the high risk category. The proportions of children with urinary tract infection recurrence were not significantly different in the low risk category between the placebo and continuous antibiotic prophylaxis groups (p = 0.151), while urinary tract infection recurrence was significantly higher in the placebo group (31.5% vs 11.4%, p = 0.001) for high risk children. Furthermore, high risk children on placebo had a 3.7-fold increased risk of urinary tract infection recurrence during 2 years of followup compared to those on continuous antibiotic prophylaxis.

CONCLUSIONS

Although the RIVUR trial concluded that children with vesicoureteral reflux benefit from continuous antibiotic prophylaxis, our reanalysis of the data demonstrates that high risk children benefit more, with a number needed to treat of 5 compared to 18 in low risk children. The clinical implications of these findings suggest a need to refine current indications for continuous antibiotic prophylaxis in children with reflux, supporting a shift toward a "selective" risk based approach for management.

Ultrasound is an effective and noninvasive method of evaluating renal swelling in infants with their first urinary tract infection

AIM

This study evaluated renal swelling in infants with a first urinary tract infection (UTI) by correlating renal length and volume with C-reactive protein (CRP) and body temperature.

METHODS

Ultrasounds were carried out on 104 infants at The Queen Silvia Children's Hospital, Gothenburg, Sweden - 58 boys (mean age 3.3 months) and 46 girls (mean age 4.8 months) - during the acute phase of their UTI. A second scan was performed on 94 of them 4 weeks later. Renal length and volume were computed to standard deviation scores (SDS).

RESULTS

The mean renal length and volume at the first ultrasound were 1.90 SDS (±1.54) and 1.67 SDS (±1.13) for the larger kidney and 0.86 SDS (±1.01) and 0.84 SDS (±0.90) for the smaller kidney. There was a significant decrease in renal length and volume between the two ultrasounds, with a mean difference of 0.96 SDS (±1.24) and 1.07 SDS (±1.10) for the larger kidney (p < 0.0001). The length and volume of the larger kidney correlated with CRP (p < 0.001), but only the renal length correlated with fever (p < 0.001).

CONCLUSION

Early ultrasound determined renal swelling in infants with a UTI and may be a valuable noninvasive way of identifying infants with renal parenchymal involvement.

Contemporary Management of Vesicoureteral Reflux

CONTEXT

Vesicoureteral reflux (VUR) remains the most interesting topic of pediatric urology due to the dynamic nature of recent controversial publications. Starting from the need for a diagnosis to the necessity and effectiveness of treatment in preventing scars, VUR remains in the mist. Although recent strong evidence helped as fog lights in this blurriness, more data are required for achieving crystal clearance. This article aims to summarize and discuss the current state of the evidence regarding VUR management.

OBJECTIVE

To provide a comprehensive synthesis of the main evidence in the literature on the current and contemporary management of VUR in children; to discuss conservative management with continuous antibiotic prophylaxis (CAP), especially its effectiveness and safety; and to review the current evidence regarding contemporary surgical techniques.

EVIDENCE ACQUISITION

We conducted a nonsystematic review of the literature using the recent guidelines and PubMed database regarding surveillance, CAP, endoscopic, open, laparoscopic, and robot-assisted ureteral surgical treatment.

EVIDENCE SYNTHESIS

Despite the striking results of previous studies revealing the ineffectiveness of CAP, more recent studies and their two fresh meta-analyses revealed a positive role for CAP in the contemporary management of VUR. One of the most interesting findings is the redundant rising of endoscopic correction and its final settlement to real indicated cases. Patient individualization in the contemporary management of VUR seems to be the keyword. The evidence in the literature showed a safe and effective use of laparoscopic and robot-assisted laparoscopic reimplantations.

CONCLUSIONS

The goal of VUR treatment is to prevent the occurrence of febrile urinary tract infections and formation of scars in the renal parenchyma. The approach should be risk adapted and individualized according to current knowledge. Individual risk is influenced by the presentation age, sex, history of pyelonephritis and renal damage, grade of reflux, bladder bowel dysfunction, and circumcision status.

PATIENT SUMMARY

Vesicoureteral reflux is a nonphysiological reflux of urine from the bladder through the ureters to the kidney. Treatment depends on the presentation of the vesicoureteral reflux (VUR). Therapeutic options range from watchful waiting to open surgery. This article aims to summarize and discuss the current state of the evidence regarding VUR management.

The Swedish infant high-grade reflux trial: UTI and renal damage

INTRODUCTION

High-grade vesicoureteral reflux (VUR) in children is associated with recurrent urinary tract infection (UTI) and renal damage. Breakthrough UTI despite continuous antibiotic prophylaxis (CAP) during the first years of life is a matter of concern and evokes early intervention. We investigated whether early endoscopic treatment (ET) of VUR grade 4-5 can reduce the risk of UTI recurrence and renal scarring.

MATERIALS AND METHODS

This prospective, randomized, controlled, multicentre, 1-year follow-up trial comprised 77 infants, <8 months of age with VUR grade 4-5 (Table) randomized to CAP (n = 39) or ET (with prophylaxis until resolution) (n = 38). Voiding cystourethrogram, ultrasound, renal scintigraphy, and free voiding observation were performed at study entry and after 1 year. Parenchymal defects were seen in 67 (87%) children at entry, 39 (34 boys, 5 girls) of them characterized as generalized. At follow-up, renal deterioration (new scars or progress in old damaged area) and symptomatic UTIs were reported.

RESULTS

There were 27 recurrent febrile UTIs in 6 (16%) children in the ET group and in 10 (26%) in the CAP group (p = 0.43), in eight (36%) girls and eight (15%) boys (p = 0.039). Successful VUR outcome (VUR 0-2) was seen in 22 (59%) in the ET and eight (21%) in the CAP group (p = 0.0014). Multiple recurrences were only seen in patients with persistent dilating reflux at follow-up (p = 0.019). Deterioration on scintigraphy was seen in eight children (9 kidneys) with no difference between treatment groups (p = 0.48) or sex (p = 0.17). Renal deterioration was associated with high bladder capacity (BC) and large residual volume (PVR) at 1 year (p = 0.0092 and p = 0.041). Six of the eight children with renal deterioration had a recurrent UTI (p = 0.0032). Seven of nine renal units with deterioration were seen in children with persistent VUR 3-5 at follow-up. Univariable logistic regression identified female sex and high PVR as positive predictors for recurrent UTI (p = 0.039 and 0.034) and high PVR tended to predict renal deterioration (p = 0.053).

DISCUSSION

No differences between the treatment groups regarding recurrent UTI and renal deterioration could be found. Increased PVR and female sex were positive predictors for UTI recurrences. VUR grade at follow-up was correlated to UTI recurrence and renal deterioration.

CONCLUSION

This study did not show any difference between ET and CAP in reducing the risk of UTI recurrence or renal deterioration. The rate of VUR resolution was higher in the ET group and VUR grade at follow-up correlated with both UTI recurrence and renal deterioration.

The Swedish infant high-grade reflux trial: Study presentation and vesicoureteral reflux outcome

INTRODUCTION

High-grade vesicoureteral reflux (VUR) in infants is associated with congenital renal abnormalities, recurrent UTI, and bladder dysfunction. Endoscopic treatment (ET) is a well-established method in children with low to moderate reflux grades, but there is a lack of randomised controlled trials regarding the use of ET versus continuous antibiotic prophylaxis in infants with high-grade VUR.

OBJECTIVE

This study aimed to determine whether high-grade VUR in infants can be treated with endoscopic injection and whether ET is superior to antibiotic prophylaxis in the treatment of VUR.

MATERIALS AND METHODS

This prospective, randomised, controlled, multicentre, 1-year follow-up trial comprised 77 infants (55 boys, 22 girls) <8 months of age with VUR grade 4-5 (n = 30/n = 47). Of the infants, 52 (68%) had bilateral VUR. Thirty-nine were randomised to antibiotic prophylaxis and 38 to ET (with prophylaxis until resolution). Voiding cystourethrogram, ultrasound, renal scintigraphy, and free voiding observation were performed at study entry and after 1 year to evaluate VUR grade, and renal and bladder function.

RESULTS

VUR grade ≤2 was seen in 22 (59%) infants in the endoscopy group and eight (21%) in the prophylaxis group at follow-up (p = 0.0014). The success rate in the endoscopy group was 100% in unilateral grade 4, falling to 31% in bilateral grade 5 (p = 0.0094). Correspondingly, the results in the prophylaxis group were 40% in grade 4 down to 0% in bilateral grade 5 (p = 0.037) (Table). Logistic regression analyses identified ET, VUR grade 4, unilaterality, and low residual urine at baseline as positive predictors of VUR down-grading to ≤2 (area under ROC curve 0.88). In four patients with reflux resolution after one injection, dilating reflux recurred at the 1-year follow-up. One patient had a UTI possibly related to ET. In our material four patients required re-implantation, of whom one was obstructive after injection.

DISCUSSION

The opportunity to offer even small infants with high-grade VUR an alternative, minimally invasive treatment option is a great advance in paediatric urology. In this high-risk group, bilateral VUR grade 5 stands out with its poor bladder function and low chance of resolution. The recurrence rate of dilating VUR after successful ET is consistent with previous studies. The limitations are the relatively small number of patients and the short follow-up.

CONCLUSION

High-grade VUR in infants can be treated with injection therapy and the resolution rate is higher than that of prophylaxis treatment. The complication rate is low and VUR grade 4, unilaterality, and low residual urine are favourable for the resolution and down-grading of VUR.

Voiding cystourethrogram: How much should we be selective?

OBJECTIVE

In this study, we examined the patients' characteristics, who underwent voiding cystourethrography (VCUG), in order to determine any selectivity for indication of this invasive method.

MATERIAL AND METHODS

After exclusion of indications of neurogenic bladder or antenatal hydronephrosis and control VCUGs, 159 VCUGs performed in our clinic within one year were evaluated. Patients are divided into three groups accoding to age. Clinical characteristic and findings of renal ultrasonography (US) and renal scintigraphy were examined.

RESULTS

Vesicoureteral reflux (VUR) was detected in 61 (38.3%) of 159 patients who underwent cystourethrographic examinations, in 45.8% of the patients with a history of recurrent urinary tract infection (UTI), in 22.0% of the patients with pathological urinary system US without history of recurrent UTI. High-grade reflux rate was significantly more frequent in renal units with pathological US findings. Severe scar was significantly more frequent in renal units with high-grade reflux when compared to renal units without reflux and those with low-grade reflux. Predictive values of recurrent UTI, scarring status and pathological US for VUR were separately analyzed and seen that likelihood of indicating VUR was increased when all 3 risk factors were assessed together.

CONCLUSION

Vesicoureteral reflux is a problem in which diagnostic process and management strategy should have to be considered in individualized manner for each patient. Before prescribing invasive VCUG, imaging urinary system by US and scintigraphy and determining whether there is recurrent UTI will improve selectivity and success of VCUG.

Urinary tract infection in small children: the evolution of renal damage over time

BACKGROUND

Our objective was to analyze the evolution of kidney damage over time in small children with urinary tract infection (UTI) and factors associated with progression of renal damage.

METHODS

From a cohort of 1003 children <2 years of age with first-time UTI, a retrospective analysis of 103 children was done. Children were selected because of renal damage at index ^99mTc-dimercaptosuccinic acid (DMSA) scintigraphy at least 3 months after UTI, and a late DMSA scan was performed after at least 2 years. Damage was classified as progression when there was a decline in differential renal function (DRF) by ≥4%, as regression when there was complete or partial resolution of uptake defects.

RESULTS

Of 103 children, 20 showed progression, 20 regression, and 63 remained unchanged. There were no differences between groups regarding gender or age. In the progression group, 16/20 (80%) children had vesicoureteral reflux (VUR) grade III-V and 13 (65%) had recurrent UTI. In multivariable regression analysis, both VUR grade III-V and recurrent UTI were associated with progression. In the regression group, 16/20 (80%) had no VUR or grade I-II, and two (10%) had recurrent UTI.

CONCLUSIONS

Most small children with febrile UTI do not develop renal damage and if they do the majority remain unchanged or regress over time. However, up to one-fifth of children with renal damage diagnosed after UTI are at risk of renal deterioration. These children are characterized by the presence of VUR grades III-V and recurrent febrile UTI and may benefit from follow-up.

Decreased Identification of Vesicoureteral Reflux: A Cautionary Tale

AIM

To find the trend in patient's visits to our centers for vesicoureteral reflux (VUR). We hypothesize that VUR diagnosis and hence possible nephropathy recognition may be diminishing because of changing practice patterns.

METHODS

Data were extracted from electronic medical records for new and follow-up patients aged 0-18 years with ICD-9/10 codes to correspond with VUR, VUR unilateral, VUR bilateral, and VUR with reflux nephropathy, as well as new patients with diagnoses of urinary tract infections (UTI) and pyelonephritis at two major pediatric centers from 2012 to 2015. Figures and statistics to reflect absolute clinic visits and annual trends were created with SPSS 2010. Linear regression was applied.

RESULTS

Annually, Le Bonheur Children's Hospital and Nationwide Children's Hospital experienced an average decrease of 13 and 17% in total VUR visits, and an average decrease of 22 and 27% in VUR nephropathy visits, respectively, for each institution. Patient visits for UTIs were reduced an average of 16% annually in both centers. Linear regression demonstrated that number of patients (patients/year ± SE) decreased annually 69 ± 19 (P = 0.02), 7 ± 2 (P = 0.02), and 67 ± 25 (P = 0.04) for VUR, VUR nephropathy, and UTI, respectively.

CONCLUSION

We conclude that the decreased number of VUR and VUR nephropathy cases identified in subspecialty clinics (Nephrology/Urology) at two major children's hospitals reflect a possible decreased identification of VUR. This trend may also be due to decreased referral of low grade cases of VUR. We cannot conclude that "undifferentiated UTI" referrals increased concomitantly to account for the decreased VUR as our data reflects a decreased trend in those visits as well. We suggest that clinicians following the American Academy of Pediatrics guidelines ensure that all UTI are accounted for and surveillance is appropriately escalated for recurrent UTI or abnormal imaging results.

Antimicrobial Resistance and Diagnostic Imaging in Infants Younger Than 2 Months Old Hospitalized With a First Febrile Urinary Tract Infection: A Population-based Comparative Study

BACKGROUND

Data on urinary tract infection (UTI) in infants ≤2 months of age are limited. We examined clinical characteristics, antimicrobial resistance, imaging findings and clinical outcomes in infants ≤2 months of age and children 2-24 months of age hospitalized with the first febrile UTI.

METHODS

Children ≤24 months of age hospitalized with their first-diagnosed febrile UTI were prospectively studied. Renal ultrasonography, Tc-dimercaptosuccinic acid scanning and voiding cystourethrography were performed in all children.

RESULTS

Of the 388 children analyzed (255 boys and 133 girls), 61 patients were ≤2 months of age, representing 15.7% of the whole population, whereas 327 patients were 2-24 months of age. Escherichia coli was the predominant bacterium, with similar antimicrobial resistance in the 2 groups, and associated E. coli bacteremia occurred in 9 patients (2.3%). Renal ultrasonography showed abnormal findings in 130 patients (33.5%), but there was no difference in the rate of abnormal findings between the groups. Vesicoureteral reflux (VUR) was present in 130 children (33.5%), including 93 (24%) with grades III-V VUR. VUR was more prevalent in the infants ≤2 months of age (P = 0.007), but there was no difference in the prevalence of grades III-V VUR between the groups. The incidence of renal scarring was 28.6% (111/388), and it did not differ between the groups.

CONCLUSIONS

There are similarities in clinical characteristics, antimicrobial resistance, imaging findings and clinical outcomes after a first UTI between the young infants ≤2 months and children 2-24 months of age. The same guidelines for the diagnosis and management after the first febrile UTI can be applied to children who are ≤24 months of age.

Genetics of Vesicoureteral Reflux

Vesicoureteral reflux (VUR) is the retrograde passage of urine from the bladder to the upper urinary tract. It is the most common congenital urological anomaly affecting 1-2% of children and 30-40% of patients with urinary tract infections. VUR is a major risk factor for pyelonephritic scarring and chronic renal failure in children. It is the result of a shortened intravesical ureter with an enlarged or malpositioned ureteric orifice. An ectopic embryonal ureteric budding development is implicated in the pathogenesis of VUR, which is a complex genetic developmental disorder. Many genes are involved in the ureteric budding formation and subsequently in the urinary tract and kidney development. Previous studies demonstrate an heterogeneous genetic pattern of VUR. In fact no single major locus or gene for primary VUR has been identified. It is likely that different forms of VUR with different genetic determinantes are present. Moreover genetic studies of syndromes with associated VUR have revealed several possible candidate genes involved in the pathogenesis of VUR and related urinary tract malformations. Mutations in genes essential for urinary tract morphogenesis are linked to numerous congenital syndromes, and in most of those VUR is a feature. The Authors provide an overview of the developmental processes leading to the VUR. The different genes and signaling pathways controlling the embryonal urinary tract development are analyzed. A better understanding of VUR genetic bases could improve the management of this condition in children.

Renal ultrasound and DMSA screening for high-grade vesicoureteral reflux

BACKGROUND

Selection of the appropriate radiologic investigation in a child after first febrile urinary tract infection (UTI) remains a contentious issue. This report investigated the effectiveness of renal bladder ultrasound (RBUS) and late 6 month dimercaptosuccinic acid (DMSA) renal scan in the detection of high-grade vesicoureteral reflux (VUR) after first febrile UTI in infants aged <1 year.

METHODS

A total of 387 infants aged <1 year with first febrile UTI who completed diagnostic follow up consisting of RBUS, voiding cystourethrogram (VCUG) and late 6 month DMSA scan were enrolled in the study. The effectiveness of RBUS and DMSA scan in the detection of high-grade VUR, including cost and benefit were assessed.

RESULTS

Abnormal RBUS was identified in 95 infants (24.5%). VUR was identified on VCUG in 79 (20.4%), of whom eight (2.1%) had high-grade VUR (grade IV-V). Abnormal renal parenchyma was identified on late 6 month DMSA scan in 22 infants (5.7%). The sensitivity of abnormal RBUS and of late 6 month DMSA scan in the prediction of high-grade VUR was 50% and 87.5%, and the proportion of infants who avoided unnecessary VCUG was 75.5% and 94.3%, respectively.

CONCLUSIONS

Fifty percent of high-grade VUR was not identified on RBUS screening after first febrile UTI. Although late 6 month DMSA scan had higher sensitivity in the detection of high-grade VUR, with the added benefit of detection of renal scars, the practical application of this method was limited due to its high cost, radiation exposure and the associated delay in decision making.

Urinary tract infection in infants: the significance of low bacterial count

BACKGROUND

In national guidelines for urinary tract infection (UTI) in children, different cut-off levels for defining bacteriuria are used. In this study, the relationship between bacterial count in infant UTI and inflammatory parameters, frequency of vesicoureteral reflux (VUR), kidney damage, and recurrent UTI was analyzed.

METHODS

We conducted a population-based retrospective study of 430 infants age <1 year with symptomatic UTI diagnosed by suprapubic aspiration. Clinical and laboratory parameters, findings on voiding cystourethrography and (99m)technetium dimercapto-succinic acid scintigraphy, and frequency of recurrence were related to bacterial count at the index UTI.

RESULTS

Eighty-three (19%) infants had bacterial counts <100,000 colony-forming units (CFU)/ml and 347 (81%) had ≥100,000 CFU/ml. There was similar frequency of VUR (19% in both groups), kidney damage (17 and 23%, p = 0.33) and recurrent UTI (6 and 12%, p = 0.17) in the low and high bacterial group. Non-E. coli species were more prevalent (19 versus 6%, p = 0.0006) and mean C-reactive protein was lower (50 vs. 79 mg/l, p <0.0001) in the low bacteria group.

CONCLUSIONS

UTI with low bacterial count is common and of importance since it may be associated with VUR and renal damage. Non-E. coli species and low inflammatory response were more prevalent in UTI with low bacterial count.

Insignificant impact of VUR on the progression of CKD in children with CAKUT

BACKGROUND

Vesicoureteral reflux (VUR) is associated with an increased risk of kidney disorders. It is unclear whether VUR is associated with progression from chronic kidney disease (CKD) to end-stage kidney disease (ESKD) in children with congenital anomalies of the kidney and urinary tract (CAKUT).

METHODS

We conducted a 3-year follow-up survey of a cohort of 447 children with CKD (stage 3-5). Rates of and risk factors for progression to ESKD were determined using the Kaplan-Meier method and Cox regression respectively.

RESULTS

Congenital anomaly of the kidney and urinary tract was the primary etiology in 278 out of 447 children; 118 (42.4 %) had a history of VUR at the start of the cohort study. There were significantly more boys than girls with VUR, whereas the proportions were similar in children without VUR. The types of urinary anomalies/complications of the two groups were significantly different. Three-year renal survival rates of the groups were not significantly different, irrespective of CKD stage. Age  < 2 years and age after puberty, stage 4 or 5 CKD, and heavy proteinuria, but not history of VUR, were significantly associated with progression to ESKD.

CONCLUSIONS

History of VUR at the start of follow-up was not associated with the progression of stage 3-5 CKD in children with CAKUT.

Urinary microprotein concentrations in the long-term follow-up of dilating vesicoureteral reflux patients who underwent medical or surgical treatment

PURPOSE

This study examined the relationship between urinary microprotein concentrations and renal functional parameters in children with dilating (grade III-V) vesicoureteral reflux (VUR) who underwent either medical or surgical treatment.

METHODS

All 44 dilating VUR patients who were followed for 4 years were screened for inclusion in this study. The patients' clinical features and clinical outcomes, as well as the urinary activities of albumin (ALB), transferrin (TRF), immunoglobulin G (IgG), alpha-1-microglobulin (α1-MG), and N-acetyl-β-glucosaminidase (NAG), were retrospectively analyzed.

RESULTS

High values of NAG, α1-MG, IgG, TRF, and ALB were noted in 73.33, 58.33, 43.33, 24.14, and 53.33 % of patients, respectively, at the first examination. Cystatin C, eGFR, and urinary microprotein levels were associated with a good prognosis after 4 years of follow-up. No differences in recurrent UTI, cystatin C concentration, most microprotein/creatinine (Cr) ratios, eGFR, or ΔGFR4 % were found between the groups. High levels of urinary proteins were found in 2.38-9.52 % of cases after 4 years of follow-up. ALB/Cr, IgG/Cr, and α1-MG/Cr levels were positively correlated with 99mTc-dimercaptosuccinic acid (DMSA) grade, and α1-MG excretion was inversely correlated with eGFR.

CONCLUSIONS

The levels of microprotein were elevated at diagnosis in a higher proportion of patients than for the other markers examined. At long-term follow-up, the reflux level had decreased or completely resolved in all patients, and the proportions of microproteins that were elevated were significantly reduced. Renal impairment measured by eGFR and DMSA grade was related to increased urinary α1-MG levels.

Sonographic assessment of the effect of vesicoureteral reflux and urinary tract infections on growth of the pediatric solitary kidney

INTRODUCTION

Perusal of recent guidelines relating to proper evaluation of infants and children with urinary tract infection (UTI) suggests that the occurrence of vesicoureteral reflux (VUR) may not have the clinical import previously ascribed to this anatomic abnormality. Patients with a solitary kidney uniquely allow investigation of the effects of both vesicoureteral reflux (VUR) and urinary tract infection (UTI) on renal growth unencumbered with the inevitable questions of laterality that confound analysis in patients with two kidneys. Several previous studies with conflicting results have addressed whether vesicoureteral reflux (VUR) impacts ultimate renal size in children with a solitary kidney. Few published studies have considered the occurrence of both urinary tract infection (UTI) and VUR on the degree of compensatory hypertrophy. This is the largest series to date investigating the effect of both UTI and VUR on the degree of compensatory hypertrophy with time.

OBJECTIVE

Our objective was to analyze sonographically determined renal growth in patients with a solitary kidney, stratifying for both the occurrence and severity of UTIs and the occurrence and severity of VUR.

STUDY DESIGN

We retrospectively reviewed the clinical history (including bladder and bowel dysfunction (BBD)) and radiology reports of 145 patients identified as having either a congenital or acquired solitary kidney in our pediatric urology practice from the prior 10 years. UTIs were tabulated by severity, where possible, and the grade of VUR was recorded based on the initial cystogram. Sonographically determined renal length was tabulated for all ultrasounds obtained throughout the study. Based on a mixed-effects model, we investigated the influence of UTI and VUR on renal growth.

RESULTS

Of the 145 patients analyzed, 105 had no VUR and 39 had VUR (16 = Gr I&II, 11 = GIII, 12 = GIV&V). Comparison showed that there was no difference in the occurrence of UTI between those without VUR (27/105 with UTI) and those with VUR (15/39 with UTI; p = 0.14). There was no difference in the occurrence of BBD in patients with VUR (15/39) and those without VUR (36/106, p = 0.62). While neither VUR nor UTI alone affected renal growth in the solitary kidney, the three-way interaction term among age, VUR, and UTI was significant (p = 0.016). The growth of the kidneys in the various patient groups is depicted in the table. From the analysis, a refluxing solitary kidney with UTI showed a significantly lower growth rate than the other groups (p < 0.001).

DISCUSSION

This study is limited by the inherent selection bias of retrospective studies. Additionally, the variability of sonographic renal measurement is well recognized. Lastly, our sample size did not allow us to incorporate the severity of the UTIs and the grades of VUR in our final regression model. Nevertheless, the overall patterns suggest that when both VUR and UTI are present, the solitary kidney demonstrates less renal growth with time. Study of larger cohorts of patients with solitary kidneys will be necessary to confirm our observations and discern what, if any, are the consequences of high-grade VUR and upper tract UTI in these patients.

CONCLUSION

In the largest series to date we were able to discern no independent effect of either VUR or UTI on sonographically determined renal growth in patients with a solitary kidney. However, UTI and VUR together result in kidneys that are smaller than other solitary kidneys not so affected. Follow-up studies of larger cohorts seem warranted to confirm these findings and discern the clinical import of these smaller kidneys.

Consequences of following the new American Academy of Pediatrics guidelines for imaging children with urinary tract infection

OBJECTIVE

Urinary tract infections (UTIs) and vesicoureteral reflux (VUR) are assumed to predispose children to renal damage. Awareness of the significance of VUR and the possibility of reducing UTI recurrence and renal damage has warranted guidelines on which patients should undergo imaging after UTI. An authoritative guideline has been issued by the American Academy of Pediatrics (AAP). This study assessed the applicability of the AAP guidelines to a subpopulation of patients with UTI, 2-24-month-old children with febrile UTI.

MATERIALS AND METHODS

The records of 394 children aged 2-24 months with their first UTI were reviewed. Data were recorded on the indications for renal and bladder ultrasonography (RBUS) and voiding cystourethrography (VCUG) according to the AAP guidelines, RBUS results, VCUG results, use of antimicrobial prophylaxis, antireflux procedures and other urological treatment, and UTI recurrence.

RESULTS

An indication for RBUS was seen in 344 patients. RBUS results were abnormal in 87, including 53 with urinary tract dilatation. An unnecessary RBUS would have been avoided in 43 patients. Seven patients with an abnormal RBUS would not have undergone RBUS. An indication for VCUG was seen in 126 patients. VCUG was performed in 206 patients; VUR was found in 72 patients, including 36 with high-grade VUR. An unnecessary VCUG would have been avoided in 82 patients. High-grade VUR would have been missed in six patients. Five patients would not have undergone surgery.

CONCLUSION

The AAP guidelines for imaging studies in children aged 2-24 months with febrile UTI seem applicable to clinical practice.

Procalcitonin, C-reactive protein, and erythrocyte sedimentation rate for the diagnosis of acute pyelonephritis in children

BACKGROUND

In children with urinary tract infection (UTI), only those with pyelonephritis (and not cystitis) are at risk for developing long-term renal sequelae. If non-invasive biomarkers could accurately differentiate children with cystitis from children with pyelonephritis, treatment and follow-up could potentially be individualized.

OBJECTIVES

The objectives of this review were to 1) determine whether procalcitonin, C-reactive protein (CRP), erythrocyte sedimentation rate (ESR) can replace the acute DMSA scan in the diagnostic evaluation of children with UTI; 2) assess the influence of patient and study characteristics on the diagnostic accuracy of these tests, and 3) compare the performance of the three tests to each other.

SEARCH METHODS

We searched MEDLINE, EMBASE, DARE, Web of Science, and BIOSIS Previews for this review. The reference lists of all included articles and relevant systematic reviews were searched to identify additional studies not found through the electronic search.

SELECTION CRITERIA

We only considered published studies that evaluated the results of an index test (procalcitonin, CRP, ESR) against the results of an acute-phase DMSA scan (conducted within 30 days of the UTI) in children aged 0 to 18 years with a culture-confirmed episode of UTI. The following cutoff values were used for the primary analysis: 0.5 ng/mL for procalcitonin, 20 mg/L for CRP and 30 mm/h for ESR.

DATA COLLECTION AND ANALYSIS

Two authors independently applied the selection criteria to all citations and independently abstracted data. We used the bivariate model to calculate pooled random-effects pooled sensitivity and specificity values.

MAIN RESULTS

A total of 24 studies met our inclusion criteria. Seventeen studies provided data for the primary analysis: six studies (434 children) included data on procalcitonin, 13 studies (1638 children) included data on CRP, and six studies (1737 children) included data on ESR (some studies had data on more than one test). The summary sensitivity estimates (95% CI) for the procalcitonin, CRP, ESR tests at the aforementioned cutoffs were 0.86 (0.72 to 0.93), 0.94 (0.85 to 0.97), and 0.87 (0.77 to 0.93), respectively. The summary specificity values for procalcitonin, CRP, and ESR tests at these cutoffs were 0.74 (0.55 to 0.87), 0.39 (0.23 to 0.58), and 0.48 (0.33 to 0.64), respectively.

AUTHORS' CONCLUSIONS

The ESR test does not appear to be sufficiently accurate to be helpful in differentiating children with cystitis from children with pyelonephritis. A low CRP value (< 20 mg/L) appears to be somewhat useful in ruling out pyelonephritis (decreasing the probability of pyelonephritis to < 20%), but unexplained heterogeneity in the data prevents us from making recommendations at this time. The procalcitonin test seems better suited for ruling in pyelonephritis, but the limited number of studies and the marked heterogeneity between studies prevents us from reaching definitive conclusions. Thus, at present, we do not find any compelling evidence to recommend the routine use of any of these tests in clinical practice.

Meaning of ureter dilatation during ultrasonography in infants for evaluating vesicoureteral reflux

PURPOSE

To investigate the meaning of ureter dilatation during ultrasonography (US) in infants for evaluating vesicoureteral reflux (VUR).

MATERIALS AND METHODS

We retrospectively reviewed abdominal US images of infants who were diagnosed with urinary tract infection (UTI group) or only hydronephrosis without UTI (control group). Hydronephrosis (graded 0-4) and ureter dilatation (present or absent) were evaluated on each side with US. Voiding cystourethrography (VCUG) within 3 months time interval with US was also reviewed and VUR was graded (0-5) on each side. Hydronephrosis, ureter dilatation, and VUR were then compared between the two groups.

RESULTS

Four hundred and three infants (142 in the UTI group and 261 in the control group) were included and VCUG was performed in 129 infants (68 in UTI and 61 in control groups). VUR grades were not different between the two groups (p=0.252). Hydronephrosis grade was not related to VUR in either group (p>0.05). However, ureter dilatation had a significant relationship with VUR in the UTI group (p=0.015), even among patients with a high-grade VUR (p=0.005). Whereas, ureter dilatation was not associated with VUR in the control group (p=0.744). The relationship between ureter dilatation and VUR was different between the two groups for both all grades (p=0.014) and high-grade (p=0.004) VUR. Ureter dilatation had 66.7% sensitivity, 80.3% specificity, and 79.4% accuracy for evaluating high-grade VUR in the UTI group.

CONCLUSION

Ureter dilatation on US can be a helpful finding for detecting VUR in infants with UTI, but not infants without UTI.

Antibiotic prophylaxis and reflux: critical review and assessment

The use of continuous antibiotic prophylaxis (CAP) was critical in the evolution of vesicoureteral reflux (VUR) from a condition in which surgery was the standard of treatment to its becoming a medically managed condition. The efficacy of antibiotic prophylaxis in the management of VUR has been challenged in recent years, and significant confusion exists as to its clinical value. This review summarizes the critical factors in the history, use, and investigation of antibiotic prophylaxis in VUR. This review provides suggestions for assessing the potential clinical utility of prophylaxis.

Gender-based differences in pediatric nuclear medicine

Gender-based differences commonly encountered in pediatric nuclear medicine reflect both basic embryologic differences of the sexes, which are evident from infancy, and evolving physiological changes due to gender, which occur as the pediatric patient grows, undergoes puberty, and matures to adulthood. It is important for a nuclear medicine physician or radiologist to know both the gender and the age of a patient when interpreting her or his studies. It is also important that the reading physician be familiar with the normally evolving physiological changes that are specific for that patient's stage of development. It is particularly important that the reading physician consider such changes when comparing serial studies of the patient that are acquired during the patient's transitions through her or his different significant stages of development. Many pediatric nuclear medicine imaging protocols are modifications or adaptations of the protocols for adult imaging. Physicians reading pediatric studies must routinely incorporate knowledge on age and gender that is relevant to the patient for any given study. The age-defined gender-based subtleties of potential findings in pediatric nuclear medicine studies are often underrecognized. However, they are often of interest and at times important in the workup of both benign entities and pathologic processes of the pediatric patient.

Predictive risk factors in childhood urinary tract infection, vesicoureteral reflux, and renal scarring management

Approaches to the management of children with urinary tract infection (UTI), vesicoureteral reflux (VUR), and renal scars have been challenged and have become controversial over the past decade. It is difficult to determine when, how, and which patients will benefit from the diagnosis and management of this condition. Therefore, the issues of diagnostic imaging, observation, follow-up, and intervention tend to be decided more on a case-by-case basis, rather than by using an algorithm. Over the past few years, there have been advances in the identification of risk factors that predispose patients with UTI to present with VUR, to develop recurrent UTIs and renal scars, to have deteriorating renal function, to show VUR improvement and/or spontaneous resolution, and to be candidates for and benefit from early surgical intervention.

Comparison of procalcitonin and different guidelines for first febrile urinary tract infection in children by imaging

BACKGROUND

We examined the ability of a procalcitonin (PCT) protocol to detect vesicoureteral reflux (VUR) and renal scarring (RS), evaluated procedural costs and radiation burden, and compared four representative guidelines for children with their first febrile urinary tract infection (UTI).

METHODS

Children aged ≤2 years with their first febrile UTI who underwent renal ultrasonography (US), acute and late technetium-99m ((99m)Tc)-dimercaptosuccinic acid scan, and voiding cystourethrography were prospectively studied. The representative guidelines applied in a retrospective simulation included the American Academy of Pediatrics (AAP), National Institute of Clinical Excellence, top-down approach (TDA), and Italian Society of Pediatric Nephrology (ISPN). These were compared in terms of ability to detect abnormalities, procedural costs and radiation.

RESULTS

Of 278 children analyzed, 172 (61.9%) had acute pyelonephritis. There was VUR in 101 (36.3%) children, including 73 (26.3%) with grades III-V VUR. RS was identified in 75 (27.0%) children. To detect VUR, TDA and PCT had the highest sensitivity for grades I-V VUR (80.2%) and III-V VUR (94.5%), respectively, whereas AAP had the highest specificity for I-V VUR (77.4%) and III-V VUR (78.0%), respectively. TDA and PCT had the highest sensitivity (100%) for detecting RS. The highest cost and radiation dose was associated with TDA, whereas AAP had the least expenditure and radiation exposure. By multivariate analysis, PCT and VUR, especially grades III-V, were independent predictors of RS.

CONCLUSIONS

There is no perfect guideline for first febrile UTI children. The PCT protocol has good ability for detecting high-grade VUR and RS. If based on available imaging modalities and reducing cost and radiation burden, clinical suggestions in the AAP guidelines represent a considerable protocol.