Diagnosis and management of vesicoureteral reflux in children

The Utility of Noninvasive Urinary Biomarkers for the Evaluation of Vesicoureteral Reflux in Children

Vesicoureteral reflux (VUR) is one of the most important disorders encountered in pediatric nephrology due to its frequency and potential evolution to chronic kidney disease (CKD). The aim of our study was to identify noninvasive and easy-to-determine urinary markers to facilitate the diagnosis and staging of VUR. We performed a cross-section study including 39 patients with VUR followed over three years (August 2021-September 2023) and 39 children without urinary disorder (the control group). We measured the urinary concentration of interleukin-6 (IL-6), cathelicidin (LL-37), and neutrophil gelatinase-associated lipocalin (NGAL) in VUR and healthy controls. Moreover, we analyzed the correlation between these biomarkers and the presence of renal scars (RS), reflux nephropathy (RN), and CKD. The NGAL concentrations were significantly higher in patients with VUR than in the controls (p = 0.02). Regarding the severity of the reflux, NGAL/creatinine and LL-37/creatinine were positively correlated with severe reflux (p = 0.04, respectively, p = 0.02). In patients with VUR and RS, LL-37/creatinine was significantly lower (p = 0.01). LL-37/creatinine with an AUC of 0.71 and NGAL/creatinine with an AUC of 0.72 could be acceptable diagnostic tests for severe VUR. In conclusion, urinary IL-6, NGAL, and LL-37 could serve as valuable markers for diagnosing and predicting outcomes in patients with VUR and RN.

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.

Association of Genetic Polymorphisms in GSTP1, GSTM1, and GSTT1 Genes with Vesicoureteral Reflux Susceptibility in the Children of Southeast Iran

Background:

Vesicoureteral reflux (VUR) disease is the most common type of urinary tract anomalies in children. Genetic risk factors may be associated with the etiology of VUR. The role of the Glutathione S-transferases (GSTs) as multifunctional enzymes is cellular oxidative stress handling. This is the first study aimed at evaluating the relative risk of GSTP1, GSTM1, and GSTT1 polymorphisms in VUR susceptibility in children and provides new important insights into the genetics of affected children.

Methods:

The study was done in 2013 in Sistan and Baluchestan University, eastern Iran. Genotyping of three GSTP1, GSTM1, and GSTT1 genes were determined using the multiplex polymerase chain reaction assay in 216 reactions for 72 VUR children and 312 reactions for 104 healthy controls.

Results:

The presence of GSTT1 deletion was associated with high risk of VUR in children, whereas GSTP1 and GSTM1 genotypes did not show the same effect. Furthermore, the combination of GSTT1/GSTM1 and GSTT1/ GSTP1 genotypes showed a significant influence on lower risk of VUR in children.

Conclusion:

Deletion of GSTT1 functional gene is a genetic risk factor causing VUR in children. Interestingly, the combination of GSTM1 and GSTP1 null genotypes with GSTT1 has shown a protective role against risk of GSTT1 deletion.

Voiding cystourethrography and 99MTC-MAG3 renal scintigraphy in pediatric vesicoureteral reflux: what is the role of indirect cystography?

BACKGROUND

Primary vesicoureteral reflux (VUR) is the most common urological anomaly in children. Voiding cystourethrography (VCUG) is considered the reference standard for the diagnosis of VUR. Even if it is a secure and standardized technique, it is still an invasive method, hence, the effort to find an alternative method to diagnose VUR. The aim of the study is to evaluate the diagnostic accuracy of ^99mTC-MAG3 scintigraphy with indirect cystography in detecting VUR and to estimate any interobserver variability in ^99mTC-MAG3 scintigraphy interpretation.

METHODS

The authors retrospectively reviewed all the pediatric patients who underwent both a VCUG and a ^99mTC-MAG3 renal scintigraphy at the study institution between 2012 and 2016.

RESULTS

A total of 86 children (and 168 renal units) were included. MAG3 scan revealed a sensitivity of 54% and a specificity of 90% with positive predictive value of 79% and negative predictive value of 73%. Each MAG3 scintigraphy was then independently and blindly evaluated by a pediatric urologist and two nuclear physicians. After revision, the concordance between VCUG and MAG3 in reflux cases dropped from 54% to 27% (on average), and the reviewers reclassified most examinations as non-conclusive.

CONCLUSIONS

^99mTC-MAG3 renal scintigraphy with indirect cystography showed low sensitivity in detecting VUR of any grade and cannot, therefore, be proposed as completely alternative to VCUG in the diagnosis of VUR. Moreover, MAG3 scintigraphy interpretation for the diagnosis of VUR has a very high interobserver variability, mostly because of the lack of a correct and complete voiding phase.

Influence of caudal block on postoperative oliguria in infants undergoing bilateral ureteroneocystostomy: a retrospective analysis

BACKGROUND

Caudal block has been widely used in children undergoing genitourinary surgery. However, the influence of caudal block on postoperative oliguria is unclear.

AIM

The aim of this study was to assess the effect of caudal block on urinary flow through the reimplanted ureter after ureteroneocystostomy and the incidence of postoperative oliguria in infants.

METHODS

This retrospective study analyzed the medical records of 121 infants aged less than 12 months who underwent bilateral ureteroneocystostomy for vesicoureteral reflux at a tertiary medical center. In all study infants, a ureteral catheter was placed in one of the two ureters in order to relieve the clinical consequences of transient ureteral obstruction and a urethral catheter was placed at the end of the ureteroneocystostomy procedure. Urinary output was assessed separately for each catheter. Logistic regression analysis was performed to identify the risk factors for oliguria from the urethral catheter.

RESULTS

Among the 121 patients, 63 (52%) received caudal block (caudal block group) and 58 (48%) did not (no caudal block group). Patient characteristics, preoperative vesicoureteral reflux grade and renal function, and intraoperative profiles were comparable between the groups. The incidence of oliguria from the urethral catheter for 8 h after the surgery was significantly higher in the caudal block group than in the no caudal block group. However, the incidence of oliguria from the ureteral catheter was comparable between the groups. In multivariate analysis, oliguria from the urethral catheter was associated with caudal block, anesthesia duration, and intraoperative dexamethasone administration. The odds for oliguria was 3.069-fold greater in patients who received caudal block than in those who did not (95%CI, 1.303-7.228, P = 0.010). On the other hand, intraoperative dexamethasone reduced the risk of oliguria.

CONCLUSION

Caudal block may be associated with postoperative oliguria in infants undergoing ureteroneocystostomy.

Inter-rater reliability of distal ureteral diameter ratio compared to grade of VUR

INTRODUCTION AND OBJECTIVE

Management of vesicoureteral reflux (VUR) remains controversial, and reflux grade constitutes an important prognostic factor. Recent work has suggested that distal ureteral diameter ratio (UDR) is a predictive factor relative to clinical outcome independent of grade. Previous studies have noted significant inter-rater variability with grading of VUR. The present study compared inter-rater reliability of reflux grade and UDR in children with primary VUR.

STUDY DESIGN

Four pediatric urologists independently reviewed, in a blinded fashion, voiding cystourethrograms. For each renal unit, grade was assigned according to the standardized international scale. The UDR was calculated by dividing the largest ureteral diameter within the false pelvis by the distance between L1-L3 vertebral bodies. Correlation within each rater was determined using Pearson's correlation coefficient. Reliability of VUR grade and UDR were calculated using two-way ANOVA model inter-rater agreement.

RESULTS

Four independent raters reliably measured VUR grade (ICC = 0.87, 95% CI = 0.78-0.93) and UDR (ICC = 0.95, 95% CI = 0.92-0.97). While UDR and grade were equally reliable measures, UDR had a tighter confidence interval. For each rater, grade and UDR were well correlated (r = 0.73-0.84; P < 0.0001). For higher-grade reflux, grade was more variable than UDR (Summary Figure). Using empirical thresholds, the increased variability of grade compared with UDR may lead to significant differences in clinical decision-making among physicians (P = 0.022).

DISCUSSION

Known discordance with grading reflux emphasizes the need for a more objective VUR measurement, as clinicians and parents often opt for clinical intervention based on both clinical course and the likelihood of spontaneous resolution. While ICC for UDR and grade were not significantly different, the confidence intervals for grade were wider due to greater variability among grade measurements. This suggests that using UDR measurements may lead to more accurate characterization of VUR and ultimately more consistent clinical decision-making across providers.

CONCLUSIONS

Ureteral diameter ratio has good inter-rater reliability among pediatric urologists, with less clinically relevant variability than VUR grade. Ureteral diameter ratio is a more objective and reliable measure than grade, and may be more useful in clinical decision-making.

Micturating cystourethrogram as a tool for investigating UTI in children - An institutional audit

BACKGROUND

Micturating cystourethrograms (MCUG) are the gold standard for evaluating vesicoureteric reflux (VUR). There is a growing consensus for increasing the threshold for performing MCUGs following urinary tract infections (UTI) in children. There are several varying guidelines. It is important to detect high-grade reflux in the setting of an UTI because of potential long-term complications.

OBJECTIVE

This audit aimed to retrospectively: (1) identify the conformance rate of local guidelines at the Women's and Children's Hospital (WCH); (2) assess predictors for an abnormal MCUG; and (3) compare local guidelines against the Royal Children's Hospital, Melbourne (RCH), National Institute for Healthcare and Excellence (NICE), and American Academy of Pediatrics (AAP) guidelines for selectively detecting high-grade reflux.

METHOD

The number of MCUGs performed from 2008 to 2012 at the WCH radiology department was collected. Patients undergoing MCUG during the 2012 calendar year were identified. Only children having an initial MCUG as part of an UTI investigation with prerequisite imaging as per guidelines were included. Each child's age, sex, referral source, reason, renal ultrasound (RUS) prior to the MCUG, MCUG result and VUR grade were recorded. The WCH guidelines were applied to determine conformance, to evaluate predictors for an abnormal MCUG, and compared against other retrospectively applied guidelines (RCH, NICE, AAP).

RESULTS/DISCUSSION

There was complete data for 168 children who underwent MCUG as part of an UTI investigation (median age 0.79 years, range 0.12-8.74, male:female 67:101). There were 67/168 abnormal MCUGs (62 children with VUR, five bladder diverticulum), and 97 refluxing renal units (43 high-grade VUR units). No posterior urethral valves (PUV) were identified as part of the UTI investigation. A total of 143/168 patients had prior RUS (normal:abnormal 67:76). The WCH guidelines had 82% conformance. There was no statistically significant association between an abnormal MCUG and age, sex, referral source, reason, or prior RUS result. The WCH guidelines may have missed five children with high-grade VUR (four children had surgery), compared with RCH, APP and NICE, with 8, 15, and 17 children, respectively, having high-grade VUR (two, five, and five children had surgery, respectively) show in the Summary Table. The retrospective study had limitations and possible selection bias (children with UTI without a MCUG). There were no standard treatment approaches for VUR; hence establishing a MCUG guideline is difficult. An alternative is the top-down approach.

CONCLUSION

Current institutional guidelines for considering MCUG following UTI in children vary considerably. The MCUG guidelines at any institution must take into account the local management guidelines for high-grade VUR.

Transplantation of mature adipocyte-derived dedifferentiated fat cells for the treatment of vesicoureteral reflux in a rat model

PURPOSE

Autologous cells potentially provide an ideal injectable substance for management in vesicoureteral reflux (VUR). The aim of this study is to examine the effects of mature adipocyte-derived dedifferentiated fat (DFAT) cell transplantation on VUR in a rat bladder pressurization-induced VUR model.

METHODS

To create VUR, Sprague-Dawley rats underwent urethral clamping and placement of cystostomy followed by intravesical pressurization. Rat DFAT cells (1 × 10⁶ cells, DFAT group, n = 5) or saline (control group, n = 5) was then injected into the bilateral vesicoureteral junctions. Two weeks later, VUR grade was evaluated on cystography. The number of apoptotic cells in the renal pelvic urothelium, the ureteral inner/outer diameter ratio and the area of connective tissue in the posterior bladder wall were measured.

RESULTS

The reflux grade in the DFAT group was significantly lower than that in the control group. The number of apoptotic cells in the renal pelvic urothelium, ureteral inner/outer diameter ratio and connective tissue area in DFAT group were significantly lower in comparison with the control group.

CONCLUSIONS

DFAT cell transplantation improved VUR and exerted nephroprotective effects in a rat VUR model.

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.

Utility of the distal ureteral diameter on VCUG for grading VUR

INTRODUCTION

For children with VUR the grade of vesicoureteral reflux (VUR) remains one of the most predictive factors relative to outcome. However, the subjective nature of the currently accepted international reflux grading system (IRGS) leads to inter-observer variation. The potential of a direct measurement of the distal ureter on the voiding cystourethrogram (VCUG) normalized to the L1-L3 vertebral body distance (ureteral diameter ratio - UDR) to augment the ability of IRGS to predict the ultimate clinical outcome has previously been reported in a group of 79 children.

OBJECTIVE

The goal of this current review was to expand the previous review and analysis in order to assess the predictive ability of the UDR with respect to earlier clinical outcome and to compare this ability to the grade of VUR while controlling for other variables.

STUDY DESIGN

This retrospective review of the VCUG of 157 children with primary VUR included 124 girls and 33 boys with a mean age of 2.7 years (7 days-13.5 years). In addition to the UDR, other variables that were analyzed included: age, gender, VUR grade, laterality, history of febrile urinary tract infection (UTI) or multiple UTIs prior to diagnosis, and bladder-bowel dysfunction (BBD). Cox regression analysis was utilized and a generalized logit model for 2-year outcome was also fitted to compare the effect of UDR and VUR grade using Wald Chi-squared analysis.

RESULTS

The 2-year outcome after the VCUG was defined as: persistent VUR (47%), spontaneous VUR resolution (15%), or operative intervention (38%). Reasons for operative intervention included: breakthrough UTI (1/3), decreased relative renal function associated with renal scarring (1/3), and failure to resolve, along with parental preference (1/3). Increasing UDR was significantly associated with increased grade and a decreased chance of spontaneous resolution. It was unlikely for a child with Grade 4, 3, or 2 VUR to have spontaneous resolution if their UDR was above 0.25, 0.3, or 0.35, respectively. In addition, higher grades of VUR, older age, and bilateral VUR were significantly associated with failure to spontaneously resolve VUR. As seen in Figure, children with grades 2 and 3 VUR less than 2 years of age had a better chance of spontaneous resolution with a larger UDR than children 2 years of age or older. When adjusting for age, grade, laterality and multiple UTIs as covariates, each unit increase of UDR of 0.1 was significantly associated with either persistent VUR (OR = 1.73, 95% CI = 1.02-2.95, P = 0.043) or the need for surgical intervention (OR = 2.40, 95% CI = 1.39-4.17, P = 0.002) compared to spontaneous resolution. When testing the effect of UDR and grade of reflux in the same model, UDR was noted to have a larger effect on predicting failure to spontaneously resolve VUR than grade (Wald Chi-Squared 13.6; P = 0.001 vs 3.62; P = 0.46, respectively).

DISCUSSION

The UDR is a readily available objective measurement on the VCUG that has demonstrated ability to enhance the International Reflux Grading System. Limitations of the current review include operative intervention in 12% of the children for failure to improve or resolve VUR. This surgical intervention inhibits determination of spontaneous resolution rates. The findings in this study reflect those in a series of children from a single institution and, therefore, may be impacted by clinical practice bias and geographic variations. Subsequent multi-institutional studies could further define the potential of UDR as either an independent or additive predictive factor for grading VUR that will further permit individualized patient management.

CONCLUSION

In this single institution series, UDR was highly correlated with VUR grade; however, UDR proved more predictive of spontaneous resolution, persistence, or operative intervention than grade.

Cyclic Direct Radionuclide Cystography in the Diagnosis and Characterization of Vesicoureteral Reflux in Children and Adults

PURPOSE

To investigate the influence of cyclic direct radionuclide cystography (RNC) on the diagnosis of vesicoureteral reflux (VUR) in children and adults.

PATIENTS AND METHODS

A total of 362 examinations were performed in patients with a mean age of 15.8 ± 17.2 years (2 months to 76.4 years, 89.5% female). The examinations were divided into 3 groups of age: A, younger than 5 years; B, 5 years and younger than 14 years; and C, older than 14 years. Repeated cycles of bladder filling without removal of the catheter were performed.

RESULTS

VUR was diagnosed in 21% of patients based on the first cycle, 5.5% in the second cycle, and 2.5% only in the third cycle. Most examinations showing VUR corresponded to grade II. Reflux occurred in only the filling phase in 10%, only the voiding phase in 27%, and both phases in 63% of patients. There was a higher incidence of reflux in groups A and B than group C after the first cycle. The second cycle was equally effective in diagnosing VUR in all 3 groups. In group A, the third cycle was more effective compared to the other groups.

CONCLUSIONS

Performing a second and a third cycle in RNC yielded an additional VUR diagnosis of 35.7%, as compared to performing only 1 cycle. The second cycle showed efficacy in all the groups, whereas the third cycle diagnosed more VUR only in group A. These results confirmed the importance of performing additional cycles in RNC for VUR diagnosis, both in children and adults.

Detecting reflux: does ureteric jet Doppler waveform have a role?

BACKGROUND

Vesicoureteral reflux (VUR) has a prevalence of 30-40 % post-febrile urinary tract infection (UTI). If not detected early and treated, renal scarring, hypertension, and renal failure may occur. Micturating cystourethrography (MCU) is an invasive procedure associated with radiation exposure. Hence, this study aimed at evaluating the utility of ureteric jet Doppler waveform (UJDW) as a screening tool in detecting VUR, and at assessing the feasibility of performing it in children aged 2-4 years.

METHODS

Any child 2-18 years old who needed an MCU was included. Exclusion criteria were active UTI, indwelling catheter, and inability to drink the required amount of fluid. The UJDW was performed prior to the MCU.

RESULTS

One hundred eighty-two ureteric units were analyzed. Sensitivity and specificity of UJDW in detecting VUR was 80.3 and 87.9 %. Twenty-three children (45 ureteric units), aged 2-4 years were compared with 73 children (137 ureteric units), aged 5-18 years. Sensitivity and specificity of UJDW in detecting VUR in 2-4 years was 77.3 and 91.3 %, respectively; while in children ≥5 years, it was 81.8 and 87.1 %, respectively.

CONCLUSIONS

UJDW has a uniformly high specificity regardless of age or etiological groups, making it a good tool for follow-up. UJDW is a feasible technique, even in children aged 2-4 years.

Interactive magnetic resonance imaging for paediatric vesicoureteric reflux (VUR)

OBJECTIVES

The current gold standard for diagnosing vesicoureteric reflux in unsedated infants is the X-ray-based Micturating CystoUrethroGram (MCUG). The aim of this study was to assess the diagnostic performance of interactive MRI for voiding cysto-urethrography (iMRVC).

METHODS

25 infants underwent conventional MCUG followed by iMRVC. In iMRVC, patients were examined using a real-time MR technique, which allows interactive control of image contrast and imaging plane location, before, during and after micturition. Images were assessed for presence and grade of VUR. Parental feedback on both procedures was evaluated.

RESULTS

iMRVC gave a sensitivity of 100%, specificity of 90.5% (95% CI: 81.6-99.4%), PPV of 66.7% and NPV of 100% in this population. There was 88% concordance (44/50 renal units) according to the presence of VUR between the two methods, with iMRVC up-grading VUR in 6 units (12%). There was very good agreement regarding VUR grade: Kappa=0.66±0.11 (95% CI 0.43-0.88). 60% of parents preferred the MRI, but did not score the two tests differently.

CONCLUSION

Interactive MRI allows dynamic imaging of the whole urinary tract without ionising radiation exposure. iMRVC gives comparable results to the MCUG, and is acceptable to parents.

Familial vesicoureteral reflux and reflux related morbidity in relatives of index patients with high grade vesicoureteral reflux

PURPOSE

The familial nature of vesicoureteral reflux is well recognized. However, there is little information about the prevalence of vesicoureteral reflux and reflux related morbidity in the relatives of index patients with vesicoureteral reflux. Therefore, we determined the prevalence of vesicoureteral reflux and reflux related morbidity in first, second and third-degree relatives of index patients with high grade vesicoureteral reflux.

MATERIALS AND METHODS

Between 1998 and 2010 the parents of 259 index patients with grade III-V vesicoureteral reflux were asked permission to screen siblings younger than age 6 years for vesicoureteral reflux. Parents of index patients with affected siblings were contacted to obtain detailed information regarding vesicoureteral reflux, recurrent urinary tract infections, end stage renal disease, hypertension and nephrectomy among first, second and third-degree relatives.

RESULTS

A total of 300 siblings of the 259 index patients were found to have vesicoureteral reflux on voiding cystourethrography. In terms of the other relatives of the 259 index patients 127 also had radiologically proven vesicoureteral reflux. Reflux related morbidity among the first, second and third-degree relatives included end stage renal disease in 21, nephrectomy in 12 and hypertension in 4. Of the 212 siblings who had dimercapto-succinic acid scans 49 (23.1%) showed evidence of renal scarring. In 73% of the relatives vesicoureteral reflux was seen on the mother's side.

CONCLUSIONS

This study, the first to our knowledge, provides important information regarding reflux related morbidity in a large cohort of familial vesicoureteral reflux in first, second and third-degree relatives of index patients. Our data clearly show that there is an increased risk of reflux related morbidity among the relatives of index patients with vesicoureteral reflux and this finding has implications for counseling.

The impact of vesicoureteral reflux treatment on the incidence of urinary tract infection

Vesicoureteral reflux (VUR) is a heterogeneous disease and its management remains one of the most controversial topics in pediatrics. Management options include surveillance, antibiotics, and surgery. The approval of dextranomer/hyaluronic acid (DHA) as a bulking agent by the Food and Drug Administration was followed by wide acceptance of endoscopic techniques as a major tool in the management of reflux. Pyelonephritis rather than VUR is the most common cause of kidney damage in children. It should be emphasized that the primary goal of diagnosing and treating VUR should be preventing this complication. There are no sufficient data in the literature to address the impact of the different treatment modalities on the incidence of febrile urinary tract infections (feb-UTIs) denoting pyelonephritis, with very few studies evaluating endoscopic treatment in light of this clear and well-defined outcome. The fact that we can correct the anatomy at the vesicoureteral junction with a simple and relatively safe outpatient procedure does not justify offering it to all patients. In this review, we attempt to critically evaluate the available literature pertaining to the impact of different treatment modalities on reducing the incidence of febrile UTIs and kidney damage, with a special emphasis on endoscopic treatment.

Efficacy of hydrodistention implantation technique in treating high-grade vesicoureteral reflux

Purpose

In the endoscopic treatment of vesicoureteral reflux, the relatively high rate of success, the simplicity of the procedure, high patient compliance, and a lack of complications has led to the increased development of injection materials and techniques. We report a method of identifying and maintaining a clear visual field during ureteral and bladder submucosal wall injection of a dextranomer/hyaluronic acid copolymer (Deflux, Oceana, Therapeutics Inc.) by use of the hydrodistention implantation technique (HIT) with the aid of temporary ureteral catheter insertion.

Materials and Methods

We prospectively reviewed patients with grade IV or V reflux who received an endoscopic injection of Deflux. Reflux grade was evaluated before and after treatment (3 months) by use of voiding cystourethrograms. Conventional sub-trigonal injection (STING) was performed with injection of Deflux underneath the bladder mucosa at the 6 o'clock position. HIT was performed either with hydrodistention or with guidewire insertion. These techniques increase visualization of the intramural portion of the distal ureteral wall. Patients with treatment failures were offered reinjection up to three times.

Results

Sixty-three patients completed endoscopic injection and follow-up of 3 months. The overall resolution rate for conventional STING was 58%, i.e., 67% for grade IV and 43% for grade V. The overall resolution rate for HIT was 80%, i.e., 93% for grade IV and 66% for grade V. The modified methods showed higher resolution rates for overall cure owing to the success in patients with grade IV reflux (p=0.026). Although the success of grade V treatment was higher with the modified method, the success rate was not statistically significant (p=0.27).

Conclusions

HIT with the use of either hydrodistention or a guidewire to aid in visualization of the intramural portion of the distal ureter is an effective treatment for high-grade vesico-ureteral reflux.

Demographic features and antibiotic resistance among children hospitalized for urinary tract infection in northwest Iran

Introduction:

Urinary tract infection (UTI) is the most common serious bacterial infection during infancy. The aim of the present study was to evaluate demographic characteristics, clinical presentations and findings, and antimicrobial resistance among infants and children hospitalized in Tabriz Children’s Hospital, Tabriz, Iran.

Methods:

In this descriptive observational study, 100 children who had been admitted with UTI diagnosis to Tabriz Children’s Hospital from March 2003 to March 2008 were studied. Demographic characteristics, chief complaints, clinical presentations and findings, urine analysis and cultures, antimicrobial resistance, and sonographic and voiding cystourethrographic reports were evaluated.

Results:

The mean age of patients was 35.77 ± 39.86 months. The male to female ratio was 0.26. The mean white blood cell count was 12,900 ± 5226/mm³. Sixty-two percent of patients had leukocytosis. The most common isolated pathogen was Escherichia coli spp (77%) followed by Klebsiella spp (10%), Enterobacter spp (9%), and Enterococcus spp (4%). Isolated pathogens were highly resistant to ampicillin, cotrimoxazole, and cephalexin (71%–96%), intermediate sensitivity to third-generation cephalosporins, and highly sensitive to ciprofloxacin (84.4%), amikacin (83.8%), and nitrofurantoin (82.8%).

Conclusion:

The most common pathogen of UTI in the hospitalized children was E. coli spp. The isolated pathogens were extremely resistant to ampicillin, and highly sensitive to ciprofloxacin and amikacin.

Genetics of vesicoureteral reflux

Primary vesicoureteral reflux (VUR) is the most common urological anomaly in children, affecting 1-2% of the pediatric population and 30-40% of children presenting with urinary tract infections (UTIs). Reflux-associated nephropathy is a major cause of childhood hypertension and chronic renal failure. The hereditary and familial nature of VUR is well recognized and several studies have reported that siblings of children with VUR have a higher incidence of reflux than the general pediatric population. Familial clustering of VUR implies that genetic factors have an important role in its pathogenesis, but no single major locus or gene for VUR has yet been identified and most researchers now acknowledge that VUR is genetically heterogeneous. Improvements in genome-scan techniques and continuously increasing knowledge of the genetic basis of VUR should help us to further understand its pathogenesis.

Concomitant vesicoureteral reflux and gastroesophageal reflux: an analytic cross-sectional study

PURPOSE

Vesicoureteral reflux (VUR) and Gastroesophageal reflux (GER) are both common disorders in children and could be associated with significant morbidities. Although they appear to be separate entities, their natural history and underlying pathophysiology are the same and they both tend to resolve over time. We aimed to appraise their concurrent occurrence and prevalence of GER in VUR patients to understand whether they can be considered different manifestations of a syndrome mainly caused by developmental delay resulting in dysfunction of the sphincters.

METHODS

Totally, 174 children ≤ 2 years of age were enrolled and 87 of them with primary VUR constituted patients group. The rest of the cases with the same age and sex distribution entered control group. All the study population underwent ultrasonographic evaluation to detect GER.

RESULTS

GER was more frequent in patients with primary VUR. GER was more prevalent in higher grades of VUR. We observed higher prevalence of GER and higher grades of VUR in younger infants demonstrating the tendency of both conditions to resolve overtime. Bilateral VUR was more prevalent among patients with higher grades of VUR. GER was more prevalent in patients with bilateral VUR and Prevalence of bilateral VUR decreased with increase in age. These findings show that the chance of concomitant GER and VUR is higher in children with more severe developmental defect of sphincters.

CONCLUSIONS

Regarding the higher prevalence of GER among VUR patients and correlation of VUR severity with co-occurrence of GER, besides the natural tendency of both conditions to resolve overtime, they may be considered parts of developmental delay syndrome of sphincters.

Quality of life in children with vesicoureteral reflux as perceived by children and parents

PURPOSE

Significant research has been dedicated to the management of vesicoureteral reflux (VUR). However, few studies have been published to evaluate the impact of this disease on quality of life. The aim of this study was a prospective examination of the health-related quality of life (HRQoL) in children with VUR who have either been treated medically (antibiotics or surveillance) or by ureteral reimplant (UR) using a validated patient satisfaction survey.

MATERIALS AND METHODS

A prospective, longitudinal study was conducted using a validated HRQoL questionnaire, the Pediatric Quality of Life Inventory (PedsQL™ 4.0 Generic Core). 353 children or parents of children with VUR, age 2-18 years, completed the survey. Statistical analysis was performed with significance set at p-value ≤ 0.05.

RESULTS

Children and parents of children with VUR did not score lower on total or subscale domains of HRQoL when compared to a historical healthy control. On univariate analysis, patients who underwent UR scored lower on total as well as physical, social, and school subscale HRQoL domains, compared to patients managed medically. When controlling for gender, ethnicity, age, reflux grade, and antibiotic use, there was no difference in total HRQoL between patients who underwent UR compared to those managed medically.

CONCLUSIONS

In terms of HRQoL, VUR is a benign clinical entity and neither antibiotic use nor UR is associated with lower HRQoL. Disease-specific quality of life surveys are needed to accurately evaluate patient and parent satisfaction in the management of VUR.

Assessing vesicoureteral reflux in live inbred mice via ultrasound with a microbubble contrast agent

Vesicoureteral reflux (VUR) is a common pediatric anomaly linked to renal scarring and hypertension. Although there are many mouse VUR models, cystograms have previously only been performed in euthanized animals, thus preventing serial assessments for VUR in the same animal and not delineating "live" physiology. Our purpose was to develop a live murine cystogram assay that could be used serially to track reflux. We injected microbubbles via transurethral catheters into bladders of C57BL6/J and C3H/HeJ inbred mouse strains that are known to have low and high VUR rates, respectively. We performed ultrasound to visualize microbubbles in the renal pelvis to determine feasibility of the procedure. We then repeated the microbubble ultrasound using a transducer allowing for visualization of both kidneys and ureters simultaneously and for 3 dimensional (3D) reconstruction. We then performed "euthanized" cystograms on all mice for comparison. C3H/HeJ mice had a strong and persistent microbubble signal in the renal pelvis and ureters bilaterally with low-contrast infusion volumes (<100 μl) and similarly showed bilateral reflux by euthanized cystograms. With larger infused volumes (≥150 μl), C57BL6/J mice had small volumes of microbubbles in the renal pelvis that cleared quickly and did not show reflux on euthanized cystograms. Thus, using animal models of known VUR, we demonstrate the utility of contrast-enhanced ultrasound to visualize reflux in live mice.

Outcome of antibiotic prophylaxis discontinuation in patients with persistent vesicoureteral reflux initially presenting with febrile urinary tract infection: time to event analysis

PURPOSE

The use of antibiotic prophylaxis for preventing urinary tract infections has recently been called into question. Some studies support discontinuation of antibiotic prophylaxis in selected groups of children with vesicoureteral reflux. We report on the outcome of this practice in a cohort of patients assembled based on initial presentation with a febrile urinary tract infection.

MATERIALS AND METHODS

We retrospectively reviewed records of patients with persistent vesicoureteral reflux without symptoms suggestive of dysfunctional elimination who discontinued antibiotic prophylaxis after being toilet trained. Exclusion criteria consisted of secondary reflux and previous surgery for vesicoureteral reflux. End points included development of febrile urinary tract infections, renal abnormalities on followup ultrasound and need for further interventions. Infection-free survival was analyzed using the Kaplan-Meier method and compared using the log rank and Cox's tests.

RESULTS

We evaluated 84 girls and 26 boys with a mean age of 5.4 years. Febrile urinary tract infections developed in 10 girls and 1 boy at an average of 17.2 months after discontinuation of antibiotic prophylaxis. In a time to event analysis group comparison showed no significant differences when patients were stratified by gender (p = 0.22), age at antibiotic prophylaxis discontinuation (p = 0.14) or disease laterality (p = 0.23). However, a significant difference was found in number of patients with high grade vesicoureteral reflux (III to V, p = 0.05) and development of symptoms suggestive of bladder/bowel dysfunction (p <0.01).

CONCLUSIONS

Our data support antibiotic prophylaxis discontinuation in the majority of patients with persistent vesicoureteral reflux who initially present with a febrile urinary tract infection, once their elimination habits have been optimized. Those with high grade reflux appear to be at increased risk for recurrent urinary tract infections. Development of dysfunctional elimination symptoms appears to be a risk factor amenable to treatment.