The detection and characterization of vesicoureteral reflux in the child

Primary vesicoureteral reflux

Primary vesicoureteral reflux (VUR) is one of the most common urological abnormalities in infants and children. The association of VUR, urinary tract infection (UTI) and renal parenchymal damage is well established. The most serious complications of VUR-associated reflux nephropathy are hypertension and proteinuria with chronic kidney disease. Over the past two decades, our understanding of the natural history of VUR has improved, which has helped to identify patients at increased risk of both VUR and VUR-associated renal injury. The main goals in the treatment of paediatric patients with VUR are the prevention of recurrent UTIs and minimizing the risk of renal scarring and long-term renal impairment. Currently, there are four options for managing primary VUR in infants and children: surveillance or intermittent treatment of UTIs with management of bladder and bowel dysfunction; continuous antibiotic prophylaxis; endoscopic subureteral injection of tissue-augmenting substances; and ureteral reimplantation via open, laparoscopic or robotic-assisted surgery. Current debates regarding key aspects of management include when to perform diagnostic imaging and how to best identify the paediatric patients that will benefit from continuous antibiotic prophylaxis or surgical intervention, including endoscopic injection therapy and minimally invasive ureteral reimplantation. Evolving technologies, such as artificial intelligence, have the potential to assist clinicians in the decision-making process and in the individualization of diagnostic imaging and treatment of infants and children with VUR in the future.

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.

Brazilian consensus on vesicoureteral reflux-recommendations for clinical practice

Introduction

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

Methods

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

Results and Discussion

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

Voiding urosonography and voiding cystourethrography in primary vesicoureteral reflux associated with mild prenatal hydronephrosis: a comparative study

BACKGROUND

Contrast-enhanced harmonic voiding urosonography has been introduced as a sensitive, radiation-free imaging method for the diagnosis of vesicoureteric reflux.

OBJECTIVE

To evaluate the occurrence/severity of vesicoureteric reflux in infants with mild prenatal hydronephrosis comparing voiding cystourethrography and voiding urosonography.

MATERIALS AND METHODS

Sixty infants with prenatal hydronephrosis were studied (anteriοposterior pelvic diameter 5-9 mm on ultrasound [US] at gestational weeks 21-30). Postnatal US was performed within the first month of life, as well as voiding cystourethrography and contrast-enhanced voiding urosonography at 1.5-2.5 months at the same session.

RESULTS

Vesicoureteric reflux was diagnosed on at least one modality in 19/60 (32%) infants, and more often on contrast-enhanced voiding urosonography (18/60, 30%) than on voiding cystourethrography (8/60, 13%), P=0.046. Among girls, reflux was more often seen on contrast-enhanced voiding urosonography (6/16, 38%) than on voiding cystourethrography (1/16, 6%), P=0.03. Vesicoureteric reflux missed by voiding cystourethrography was more severe (Grades I, II and III in one, nine and four kidney-ureter-units, respectively), compared with a single case missed by contrast-enhanced voiding urosonography (Grade I in one kidney-ureter-unit).

CONCLUSION

In the absence of a reference standard, our results imply that voiding cystourethrography might underdiagnose reflux, and/or contrast-enhanced voiding urosonography may overdiagnose reflux.

An update on renal scarring after urinary tract infection in children: what are the risk factors?

AIM

The aim of this study was to present updated information on clinical, laboratory, and imaging risk factors and predictors of renal scarring after first or recurrent febrile UTIs, which may be associated with renal scarring.

METHODS

PubMed was searched for current data on possible risk factors and predictors of renal scarring after febrile urinary tract infections in children.

RESULTS

Recurrence of acute pyelonephritis is an independent risk factor for renal scarring, while the duration of fever before treatment initiation is mainly associated with acute pyelonephritis and its severity. Severe vesicoureteral reflux is an important independent risk factor for the development of renal scarring after a febrile urinary tract infection.

CONCLUSIONS

Certain clinical parameters could be used to identify children at high risk for renal scarring after febrile urinary tract infection, helping clinicians to reserve dimercaptosuccinic acid scan for selected cases.

The learning curve of contrast-enhanced 'microbubble' voiding urosonography-validation study

INTRODUCTION

Vesicoureteral reflux (VUR) is a common pediatric urologic condition associated with urinary tract infection and pyelonephritis. It can be diagnosed via fluoroscopic voiding cystourethrogram (VCUG) and, more recently, contrast-enhanced voiding ultrasonography (ceVUS), which does not expose the patient to ionizing radiation. Voiding urosonography contrast agents used for the diagnosis of VUR have been widely available in Europe but were approved by the Food and Drug Administration for use in the United States only in 2016.

OBJECTIVE

The objective was to optimize a protocol and compare the diagnostic performance of ceVUS to fluoroscopic VCUG in an academic medical center naïve to previous use of contrast-enhanced voiding urosonography.

STUDY DESIGN

Thirty-nine patients referred for clinically indicated evaluation of VUR were enrolled between September 2016 and March 2017. Patients underwent contrast-enhanced ultrasonography with prediluted Lumason and under the same catheterization underwent fluoroscopic VCUG. Comparative grading was performed by pediatric radiologists on-site at the time of examination.

RESULTS

Reflux was observed in 16 of 39 patients (20 of 64 renal units) ranging from grades 1 through 5. VCUG and ceVUS were concordant for detecting reflux in 10 of 39 patients (14 of 84 renal units) and excluding reflux in 23 of 39 patients (64 of 84 renal units) (Fig. 1). Using contrast enhanced voiding urosonography, 1 of 20 renal units had high-grade and 2 of 20 renal units had low-grade reflux that was not found on fluoroscopy. Using fluoroscopy, 1 of 20 renal units had high-grade and 2 of 20 renal units had low-grade reflux that had not been found on ceVUS. Two of 20 renal units were upgraded from low-grade on ceVUS to high-grade on fluoroscopy. This corresponds to a Cohen's kappa of 0.72 (confidence interval [CI] 0.54-0.91) or 'moderate.'

DISCUSSION

During our investigation, we noted that there was a technical learning curve related to poor contrast mixing and the need to titrate the concentration of Lumason. However, over the course of the study, we were able to correct the technical aspects. Ultimately, our results showed good correlation between VCUG and Lumason ceVUS and only slightly less correlation than published studies by experienced centers. Future studies with voiding should allow for improved urethral visualization.

CONCLUSION

While there is a considerable learning curve to the implementation of ceVUS for the diagnosis of pediatric VUR, these technical aspects can be corrected. Even a center previously naïve to contrast-enhanced ultrasound technology can, over a short period of time, demonstrate good correlation between VCUG and ceVUS in the diagnosis of VUR. Translation of ceVUS into clinical practice is an alternative to VCUG for diagnosis of reflux, is feasible, and can eliminate the radiation exposure associated with a VCUG.

Late presentation of vesicoureteral reflux: An unusual cause of pyelonephritis in adults

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Vesicoureteral reflux presenting for the first time in adults is rare.

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The diagnosis should be suspicious in adult patients with recurrent Pyelonephritis without recognizable cause.

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Endoscopic treatment with bulking agents is a minimally invasive technique with good results for adult vesicoureteral reflux.

Introduction: Vesicoureteral reflux (VUR) corresponds to the reflux of urine from the bladder into the upper urinary system. It can be a congenital or an acquired anomaly and although its incidence is high in children it is uncommon in the adult life. One of its presentations in the adult population is the presence of recurrent Pyelonephritis.

Case presentation: Here we report a case of an adult patient with repetitive uncomplicated pyelonephritis caused by VUR. VUR was successfully managed endoscopically with subureteral injection of a bulking agent. A literature review of adult presenting VUR was performed.

Discussion: The first presentation of VUR in the adult life is rare. One of the most typical presentation is the presence of recurrent uncomplicated Pyelonephritis. Although no guidelines exists to study the presence of VUR in adult patients with Pyelonephritis, in the presence of several recurrent episodes of Pyelonephritis we should think in VUR as a possible cause. Even in adults, endoscopic management of VUR is an effective treatment with low morbidity.

Conclusion: VUR can first present in the adult life, with recurrent episodes of UTI. The diagnosis is a suspicious one and is confirmed by VUCG. VUR in adults can be effectively managed with endoscopic injection of bulking agents.

Long-term Outcomes of Endoscopic Anti-reflux Surgery in Pediatric Patients with Vesicoureteral Reflux: Urinary Tract Infection, Renal Scarring, and Predictive Factors for Success

BACKGROUND

To report the long-term outcomes of endoscopic surgery (ES) in pediatric patients with vesicoureteral reflux in terms of success rate, urinary tract infection, and renal function.

METHODS

We retrospectively reviewed the records of 73 pediatric patients (110 ureters) who underwent ES for vesicoureteral reflux. Ultrasonography was performed 1, 3, and 12 months postoperatively. Voiding cystourethrography was performed 3 months postoperatively and repeated after 1 year if vesicoureteral reflux persisted. Success was defined as the absence of reflux at the first voiding cystourethrography. Renal scans were performed at least 12 months postoperatively. Renal function deterioration was defined as a new scar or a greater than 5% decrease in function.

RESULTS

The median follow-up duration was 24 (12-118) months. The overall success was 65.6%, while it was 78.9%, 87.0%, 62.5%, 37.5%, 66.7% for grades I, II, III, IV, and V, respectively. In multivariate analyses, significant predictive factors for success were vesicoureteral reflux grade (odds ratio [OR], 0.28; P < 0.001) and mound detection at the first postoperative ultrasonography (OR, 13.53; P < 0.001). Renal function deterioration was found in 8 (15.3%) ureters and was less common in those with successful surgeries than in those with failures (9.5% vs. 40.0%; P = 0.035). No significant predictive factor for renal function deterioration or urinary tract infection was found.

CONCLUSION

Successful short-term outcomes of ES are expected in low-grade vesicoureteral reflux, especially when a mound is detected by postoperative ultrasonography. However, unpredictable long-term renal deterioration warrants continued follow-up.

Contrast-enhanced Voiding Urosonography for Vesicoureteral Reflux Diagnosis in Children

Contrast-enhanced voiding urosonography (ceVUS) is a dynamic imaging technique that makes it possible to study the structure of the urinary tract after the administration of intravesical contrast material. Initially, ceVUS was indicated mainly to study vesicoureteral reflux (VUR); however, since the ability of ceVUS to depict the structure of the urethra was demonstrated in both sexes, ceVUS is now indicated for examination of the entire urinary tract. The main benefit of ceVUS is that it does not use ionizing radiation. In recent years, fundamental changes have occurred in the understanding of VUR. The lessening effect of VUR and the low rate of occurrence of urethral pathologic conditions have given rise to changes in the indications for tests for these conditions. In addition to being able to help confirm a diagnosis of VUR, the ceVUS technique can be used to depict obstructive and nonobstructive urethral pathologic conditions, as well as normal variants, on high-quality images. Furthermore, ceVUS enables real-time assessment of voiding function. For these reasons, ceVUS should be not only an alternative to voiding cystourethrography, but also the technique of choice for the study of the entire urinary tract in pediatric patients. Online supplemental material is available for this article. ^©RSNA, 2017.

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.

Nuclear Medicine in Pediatric Nephro-Urology: An Overview

In the context of ante-natally diagnosed hydronephrosis, the vast majority of children with a dilated renal pelvis do not need any surgical treatment, as the dilatation resolves spontaneously with time. Slow drainage demonstrated at Tc-99m-mercaptoacetyltriglycine (MAG3) renography does not necessarily mean obstruction. Obstruction is defined as resistance to urinary outflow with urinary stasis at the level of the pelvic-ureteric junction (PUJ) which, if left untreated, will damage the kidney. Unfortunately this definition is retrospective and not clinically helpful. Therefore, the identification of the kidney at risk of losing function in an asymptomatic patient is a major research goal. In the context of renovascular hypertension a DMSA scan can be useful before and after revascularisation procedures (angioplasty or surgery) to assess for gain in kidney function. Renal calculi are increasingly frequent in children. Whilst the vast majority of patients with renal stones do not need functional imaging, DMSA scans with SPECT and a low dose limited CT can be very helpful in the case of complex renal calculi. Congenital renal anomalies such as duplex kidneys, horseshoe kidneys, crossed-fused kidneys and multi-cystic dysplastic kidneys greatly benefit from functional imaging to identify regional parenchymal function, thus directing further management. Positron emission tomography (PET) is being actively tested in genito-urinary malignancies. Encouraging initial reports suggest that F-18-fluorodeoxyglucose (FDG) PET is more sensitive than CT in the assessment of lymph nodal metastases in patients with genito-urinary sarcomas; an increased sensitivity in comparison to isotope bone scans for skeletal metastatic disease has also been reported. Further evaluation is necessary, especially with the promising advent of PET/MRI scanners. Nuclear Medicine in paediatric nephro-urology has stood the test of time and is opening up to new exciting developments.

Polyacrylamide Hydrogel as a Bulking Agent for the Endoscopic Treatment of Vesicoureteral Reflux: Long-Term Results and Safety

PURPOSE

Polyacrylamide hydrogel has been shown to offer good short-term success for the endoscopic treatment of vesicoureteral reflux. Our objective was to provide long-term results of its efficacy and safety.

MATERIALS AND METHODS

We performed a prospective study using polyacrylamide hydrogel to treat all grades of vesicoureteral reflux. Every patient underwent endoscopic injection of polyacrylamide hydrogel followed by 3-month postoperative renal ultrasound and voiding cystourethrogram. Renal ultrasound was repeated at 12 and 36 months. Treatment success was defined as the absence of de novo or worsening hydronephrosis and the absence of reflux. Safety elements included new or worsening hydronephrosis, calcifications of the injected material and urinary tract infections.

RESULTS

A total of 76 patients (123 refluxing renal units) were assessed. Median age at surgery was 45 months and median followup was 36 months. Median injected volume of hydrogel per refluxing renal unit was 1.0 ml. The overall success rate 3 months after a single injection was 71%. During long-term followup 68 of 70 eligible patients underwent 12-month ultrasound and 40 of 46 underwent 36-month ultrasound. No upper tract deterioration or bulking agent calcifications were reported. Nine (12%) and 2 patients (3%) presented with nonfebrile and febrile urinary tract infections, respectively.

CONCLUSIONS

The success rate of polyacrylamide hydrogel for endoscopic treatment of vesicoureteral reflux is comparable to published results of dextranomer hyaluronic acid. The long-term safety data and potential lower cost of polyacrylamide hydrogel provide further support for the use of this nonparticulate bulking agent to treat reflux.

Role of new biomarkers for predicting renal scarring in vesicoureteral reflux: NGAL, KIM-1, and L-FABP

BACKGROUND

Reflux nephropathy is the most serious complication of vesicoureteral reflux (VUR). The aim of this study was to assess the role of urinary levels of neutrophil-gelatinase-associated lipocalin (NGAL),kidney injury molecule-1 (KIM-1), and liver-type fatty-acid-binding protein (L-FABP) in the early diagnosis of reflux nephropathy in patients with VUR.

METHODS

This study assessed 123 patients with primary VUR and 30 healthy children as a control group. The children were divided into five groups: Group A, patients with VUR and renal parenchymal scarring (RPS); Group B, patients with VUR and without RPS; Group C, patients with RPS and resolved VUR; Group D, patients with resolved VUR and without RPS; Group E, healthy reference group.

RESULTS

Median urinary NGAL (uNGAL)/Creatinine (Cr) was significantly higher in patients with than those without RPS and the control group (p = 0.0001). Median uKIM-1/Cr was similar in all groups (p = 0.417). Median uL-FABP/Cr was significantly higher in patients with RPS than in the reference group (p < 0.05).

CONCLUSIONS

Urinary NGAL levels may be used as a noninvasive diagnostic marker for predicting renal scarring in reflux nephropathy.

Renal Scarring in the Randomized Intervention for Children with Vesicoureteral Reflux (RIVUR) Trial

BACKGROUND AND OBJECTIVES

The main objectives of the Randomized Intervention for Children with Vesicoureteral Reflux (RIVUR) trial were to evaluate the role of antimicrobial prophylaxis in the prevention of recurrent urinary tract infection (UTI) and renal scarring in children with vesicoureteral reflux (VUR). We present a comprehensive evaluation of renal scarring outcomes in RIVUR trial participants.

DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS

This multicenter, randomized, placebo-controlled trial enrolled 607 children aged 2-71 months with grade 1-4 VUR diagnosed after a first or second febrile or symptomatic UTI. Study participants received trimethoprim-sulfamethoxazole or placebo and were followed for 2 years. Renal scarring was evaluated by baseline and follow-up (99m)technetium dimercaptosuccinic acid (DMSA) renal scans that were reviewed independently by two blinded reference radiologists.

RESULTS

At the end of the study, 58 (10%) of 599 children and 63 (5%) of 1197 renal units had renal scarring. New renal scarring did not differ between the prophylaxis and placebo groups (6% versus 7%, respectively). Children with renal scarring were significantly older (median age, 26 versus 11 months; P=0.01), had a second UTI before enrollment (odds ratio [OR], 2.85; 95% confidence interval [95% CI], 1.38 to 5.92), were more likely to be Hispanic (OR, 2.22; 95% CI, 1.13 to 4.34), and had higher grades of VUR (OR, 2.79; 95% CI, 1.56 to 5.0). The proportion of new scars in renal units with grade 4 VUR was significantly higher than in units with no VUR (OR, 24.2; 95% CI, 6.4 to 91.2).

CONCLUSIONS

Significantly more renal scarring was seen in relatively older children and in those with a second episode of febrile or symptomatic UTI before randomization. Preexisting and new renal scars occurred significantly more in renal units with grade 4 VUR than in those with low-grade or no VUR. Antimicrobial prophylaxis did not decrease the risk of renal scarring.

Relationship between radiologist training level and fluoroscopy time for voiding cystourethrography

OBJECTIVE

The objective of our study was to determine whether voiding cystourethrography (VCUG) fluoroscopy time is related to the training level of the performing radiologist.

MATERIALS AND METHODS

VCUG reports with normal findings from 2008 to 2011 at one institution were retrospectively reviewed. The average fluoroscopy time was calculated for first-year radiology residents, senior radiology residents, pediatric radiology fellows, and attending pediatric radiologists. The average fluoroscopy time was also calculated for radiologist sex, patient sex, and patient age group. The analysis of variance was used to evaluate differences in average fluoroscopy times between training levels of radiologists, patient age groups, and patient sexes.

RESULTS

We reviewed 784 VCUG reports with normal findings: 340 (43.4%) were performed by first-year residents; 181 (23%), by senior residents; 161 (20.5%), by fellows; and 102 (13%), by attending pediatric radiologists. The overall average fluoroscopy time was 1.86 minutes (SD ± 0.98). The attending pediatric radiologists had the shortest average fluoroscopy time (1.63 ± 0.92 minutes), significantly shorter than senior residents (1.96 ± 1.09 minutes; p = 0.0070) and fellows (1.91 ± 0.85 minutes; p = 0.0255). There was no significant difference between attending radiologists and first-year residents (1.85 ± 1.00 minutes; p = 0.0550). The male-to-female ratio of radiologists was 54% versus 46%, with identical average fluoroscopy times: male radiologists, 1.86 ± 1.05 minutes; female radiologists, 1.86 ± 0.90 minutes. There was no significant difference in average fluoroscopy times among patient age groups: 1.93, 1.76, and 1.78 minutes, respectively, for groups A (0-1 years), B (> 1 to ≤ 5 years), and C (> 5 years) (p = 0.1750, 0.4605, 0.6303). The average fluoroscopy time for male patients (2.02 ± 1.00 minutes) was significantly longer than that for female patients (1.71 ± 0.95 minutes; p < 0.0001).

CONCLUSION

Attending pediatric radiologists have the shortest fluoroscopy time; the differences between their average time compared with the average times of pediatric radiology fellows and of senior radiology residents were statistically significant. The average fluoroscopy time is longer for male patients than for female patients.

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.

Cross-sectional evaluation of parental decision making factors for vesicoureteral reflux management in children

PURPOSE

Parental decision making in children with vesicoureteral reflux has potentially become more complex with the evolution of ethnic diversity in the United States, the Internet, the publication of contradictory clinical data and the emergence of minimally invasive surgery. We performed a cross-sectional study of parental management for pediatric vesicoureteral reflux.

MATERIALS AND METHODS

We administered a 26-item questionnaire to parents of children with vesicoureteral reflux seen at Texas Children's Hospital urology offices or undergoing antireflux surgery at that institution. Univariate and multivariate analysis was done on patient disease characteristics, demographics, predicted reflux duration, surgery success rate, antibiotic cessation, complication risk, financial considerations, urologist recommendations, Internet information, friend recommendations, and postoperative voiding cystourethrography, renal ultrasound and recovery.

RESULTS

Enrolled in the study were 15 boys and 49 girls with a mean age of 3.5 years and a mean reflux grade of 2.8. Of the cases 37 were bilateral. Parents chose endoscopic treatment in 38 children, open ureteroneocystostomy in 9, antibiotic prophylaxis in 14 and observation without antibiotics in 3. Univariate analysis suggested that Hispanic parents rated ultrasound and financial considerations as more important than white parents (p <0.05). Multivariate analysis revealed that differences seen on univariate analysis may have been due to an association between race and income. Finally, 93.6% of parents rated urologist opinion as very or extremely important.

CONCLUSIONS

Data indicate that the parents of our patients highly value the opinion of the pediatric urologist when choosing treatment for their children with vesicoureteral reflux. Despite social changes the physician-parental relationship remains critical. Differences in parental decision making may be linked to associations between race and income.

Diagnosis and management of vesicoureteral reflux in children

Critical evaluation of previously accepted dogma regarding the evaluation and treatment of vesicoureteral reflux (VUR) has raised significant questions regarding all aspects of VUR management. Whereas the standard of care previously consisted of antibiotic prophylaxis for any child with VUR, it is now unclear which children, if any, truly benefit from antibiotic prophylaxis. Operative intervention for VUR constitutes overtreatment in many children, yet there are limited data available to indicate which children benefit from VUR correction through decreased rates of adverse long-term clinical sequelae. Studies with longer follow-up demonstrate decreased efficacy of endoscopic therapy that was previously hoped to approach the success of ureteroneocystostomy. Prospective studies might identify risk factors for pyelonephritis and renal scarring without antibiotic prophylaxis. Careful retrospective reviews of adults with a history of reflux might allow childhood risk factors for adverse sequelae to be characterized. Through analysis of multiple characteristics, better clinical management of VUR on an individualized basis will become the new standard of care.

Vesicoureteral reflux and urinary tract infection: evolving practices and current controversies in pediatric imaging

OBJECTIVE

Pediatric patients with urinary tract infection (UTI) undergo imaging tests to detect vesicoureteral reflux (VUR) in the belief that VUR correlates to risk of renal scarring. This article describes recent evolution and controversies in the management of UTI and VUR.

CONCLUSION

Multitechnique imaging of UTI and VUR is complex and controversial. Evolution in practice patterns is motivated by the desire to rationally minimize unnecessary interventions and radiation exposure. Ongoing evidence-based research is needed to further improve practice guidelines.

Voiding cystography practices and preferences of North American pediatric urologists

PURPOSE

Little consensus exists regarding the choice of a specific modality of voiding cystography in the evaluation and management of vesicoureteral reflux. We hypothesized that choices of pediatric urologists are based on technical factors of the studies themselves, as well as institutional factors unique to their hospital(s). Therefore, we surveyed pediatric urologists to determine their current practices and preferences of modalities of voiding cystography.

MATERIALS AND METHODS

We mailed an anonymous survey of 40 questions to all fellows of the American Academy of Pediatrics Section on Urology.

RESULTS

Surveys were returned from 186 of 301 fellows (62%). Of the respondents 57% were in academic, 30% in private and 13% in mixed practices. Given a choice of fluoroscopic voiding cystourethrography, radionuclide cystography and voiding ultrasonography, fluoroscopic voiding cystourethrography was preferred by 98% and 96% of respondents for initial evaluation of urinary tract infection in males and females, respectively, 96% for assessment of prenatal hydronephrosis, 54% for followup of vesicoureteral reflux, 59% for screening siblings, and 63% and 66%, respectively, after open and endoscopic correction of vesicoureteral reflux. Voiding ultrasonography was preferred by less than 10% of respondents in all groups, and radionuclide cystography was preferred by the remainder. Voiding images of the urethra, child-friendliness of staff, sensitivity and accuracy were factors most important in choosing a test. Of the respondents 83% reported full-time access to pediatric radiologists at their primary hospital, although a minority had full-time access to pediatric radiologists at additional institutions. Sedation was used in some or most cases by 29%, rarely by 56% and never by 15% of respondents.

CONCLUSIONS

Pediatric urologists prefer fluoroscopic voiding cystography in all situations to evaluate vesicoureteral reflux but the proportion varies by indication. Diagnostic and patient issues are of greater concern than radiation dose. Variability in access to pediatric radiologists and ability to obtain the desired study may also alter ordering practices.

Comparison of direct radionuclide cystography and voiding direct cystography in the detection of vesicoureteral reflux

PURPOSE

The aim of this study is to compare the results of direct radionuclide cystography (DRNC) and voiding cystourethrography (VCUG) in a group of children with a high suspicion of vesicoureteral reflux (VUR).

METHODS

For this purpose, 25 children were studied with both VCUG and DRNC. Among 50 ureter units able to be compared 39 ureter units did not show any VUR on either study. Eleven ureter units (10 children) had VUR either on one study or on both (VCUG and DRNC). In the children who had VUR on either study, a dimercaptosuccinic acid scintigraphy (DMSA) was performed to determine their cortical function.

RESULTS

We identified the following four patterns: 1) Five ureter units (five children) read positive on DRNC who were negative on VCUG and four of these children had positive findings on DMSA; 2) Four ureter units (four children) read positive on VCUG who were negative on DRNC, and two of them had positive findings on DMSA; 3) Two ureters (one child) read positive in both studies and also had abnormal DMSA findings; 4) Thirty-nine ureter units read as negative on both studies.

CONCLUSION

Although the results of these two methods did not show a significant difference, DRNC offers a high sensitivity in the younger age group whereas VCUG seems to be more sensitive in the older age group. DRNC also offers continuous recording during the study, ease of assessment and lower radiation dose to the gonads, which makes it a preferable method for the initial diagnosis and follow-up of VUR.

Vesicoureteral reflux, reflux nephropathy, and end-stage renal disease

Objective. To review the contribution of vesicoureteral reflux and reflux nephropathy to end-stage renal disease. Data Source. Published research articles and publicly available registries. Results. Vesicoureteral reflux (VUR) is commonly identified in pediatric patients and can be associated with reflux nephropathy (RN), chronic kidney disease (CKD), and rarely end-stage renal disease (ESRD). Patients with reduced GFR, bilateral disease, grade V VUR, proteinuria, and hypertension are more likely to progress to CKD and ESRD. Because progression to ESRD is rare in VUR and often requires many decades to develop, there are limited prospective, randomized, controlled trials available to direct therapy to prevent progression to ESRD. Conclusions. Identification of patients with increased risk of progression to CKD and ESRD should be the goal of clinical, biochemical, and radiological evaluation of patients with VUR. Treatment of patients with VUR should be directed at preventing new renal injury and preserving renal function.

Therapy Insight: what nephrologists need to know about primary vesicoureteral reflux

Vesicoureteral reflux (VUR) is the abnormal, retrograde flow of urine from the bladder to the upper urinary tract. This disease affects about 1% of otherwise normal children, 30-50% of those who present with urinary tract infections, and approximately 10% with prenatally diagnosed hydronephrosis. Over the past 50 years, tremendous progress has been made in the diagnosis, treatment and management of VUR. The realization that VUR is probably a component of generalized dysfunction of the lower urinary tract (i.e. dysfunctional elimination syndrome) has further enhanced understanding of the disease. This Review covers basic pathogenesis, diagnosis, management, clinical presentation, and current controversies surrounding VUR.

Patient dose reduction during voiding cystourethrography

Voiding cystourethrography (VCUG) is a commonly performed examination in a pediatric uroradiology practice. This article contains suggestions on how the radiation dose to a child from VCUG can be made "as low as reasonably achievable" (ALARA). The pediatric radiologist should consider the appropriateness of the clinical indication before performing VCUG and utilize radiation exposure techniques and parameters during VCUG to reduce radiation exposure to a child. The medical physicist and fluoroscope manufacturer can also work together to optimize a pulsed-fluoroscopy unit and further reduce the radiation exposure. Laboratory and clinical research is necessary to investigate methods that reduce radiation exposures during VCUG, and current research is presented here.

Comparison of direct radionuclide cystography and voiding cystourethrography in detecting vesicoureteral reflux

BACKGROUND

Fluoroscopic voiding cystourethrography (VCUG) is a widely used imaging test for the diagnosis of vesicoureteral reflux (VUR). However, high gonadal radiation and intermittent imaging are the main disadvantages of VCUG. Direct radionuclide cystography (DRC) has been advocated for the detection of VUR with increased sensitivity and low radiation doses, however, having the disadvantage of providing less anatomical details for urethral evaluation. In this study, DRC has been compared with standard fluoroscopic VCUG for detection of VUR.

METHODS

A total of 41 children (82 kidney ureter units, KUU) aged 1 month-126 months (median, 15 months) were studied sequentially using DRC and VCUG. The indications of VUR studied were urinary tract infection in 29 children, VUR follow up in eight children and antenatal dilatation history in four children.

RESULTS

A total of 18 refluxing ureters were detected by DRC, 22 refluxing ureters by VCUG and 14 refluxing ureters by both methods. The two methods were concordant for the detection and exclusion of VUR in 85% of KUU. VUR was missed by VCUG in four KUU (three severe, one mild) whereas VUR was missed by DRC in eight KUU (four grade I, four grade III).

CONCLUSIONS

There was a good correlation between DRC and VCUG in the evaluation of VUR. DRC provides continuous monitoring and low gonadal radiation exposure. DRC can be used in the diagnosis of VUR as an alternative to VCUG in selected cases.

[Modern imaging technology for childhood urinary tract infection]

Imaging in childhood urinary tract infection (UTI) is still a matter of debate. There are established guidelines, however new knowledge and the changed medical environment have enhanced this ongoing discussion. These new insights have impacted therapy and consequently the imaging algorithm. Modern imaging methods -- particularly MRI and modern ultrasound (US) -- are less invasive with a lower radiation burden. Additionally, it has been shown that VUR is a poor predictor for renal scarring out, which affects long-term results. Furthermore, the majority of UT malformations is depicted by prenatal US. The most crucial aspect of improving long-term outcome appears to be the early and reliable depiction of UTI and effective treatment to prevent renal scarring. This review tries to present this new knowledge and to discuss the potential of modern imaging. Recent changes in imaging algorithms are highlighted and an outcome-oriented algorithm that addresses these recent developments is proposed, without lightly abandoning established standards. It consists of an orienting US and -- for depiction of renal involvement -- amplitude coded color Doppler sonography or renal static scintigraphy (considered the gold standard, particularly for evaluating scars); in future MRI may play a role. Based on this concept, only patients with renal damage as well as patients with complex urinary tract malformations or intractable recurrent UTI may have to undergo VCUG.

Cyclic contrast-enhanced harmonic voiding urosonography for the evaluation of reflux. Can we keep the cost of the examination low?

The purpose of this study was to evaluate whether a second cycle of contrast-enhanced voiding urosonography (VUS) with no added contrast medium (CM) can increase the detection rate of vesicoureteral reflux (VUR). One hundred twelve consecutive children with a mean age of 2.9 years with 224 kidney-ureter units (KUU) underwent two cycles of contrast-enhanced harmonic VUS. The first cycle of VUS was performed with 3.5-12.5 ml of suspension 300 mg/ml SH U 508 A and was followed immediately by a second cycle with only saline without adding CM. VUR was detected in 57 KUU from 44 children (39%) at the first cycle of VUS. Eight of the remaining 68 non-refluxing children (12%) demonstrated VUR at the second cycle (P=0.045). Most cases of missed reflux at the first cycle were grade II (75%). However, in two KUU from two children missed reflux was grade III. In one child reflux (grade II) was missed on the second cycle. Comparing the second cycle of VUS with the first cycle, concordant findings regarding the presence or absence as well as the grade of reflux were found in 94% of KUU. A second cycle of contrast-enhanced harmonic VUS with no added CM discloses significantly more cases of VUR at no additional cost for the examination.

Cystoscopic and DMSA findings in relation to types of reflux demonstrated on percutaneous direct radionuclide cystography in children

BACKGROUND

The new technique of percutaneous direct radionuclide cystography (PDRC) allows the accurate demonstration of vesicorenal reflux under physiological conditions during resting and micturition phases. Five types of reflux have been described, the clinical relevance of which is uncertain.

OBJECTIVE

To determine whether a relationship exists between the type of reflux identified on PDRC and the appearance of the ureteric orifice at cystoscopy or the prevalence of renal abnormalities.

MATERIALS AND METHODS

The reports of 281 PDRC examinations were reviewed and 76 children with reflux formed the population of this study. Studies of these children were reviewed to classify the reflux as types 1-5, and patient records were searched for cystoscopy and DMSA scan reports.

RESULTS

Regardless of the type of reflux, the ureteric orifices were found to be open at cystoscopy in 60-66% of refluxing units. DMSA scan abnormalities were present in 68% of units with reflux at rest, 61% of units with reflux on micturition and 86% of units with reflux on both resting and micturition phases. In comparison with contralateral units that did not reflux, the presence of reflux had a significant association with openness of the ureteric orifice ( p<0.00001) and DMSA abnormality ( p<0.005).

CONCLUSIONS

Reflux of any type is strongly associated with an open ureteric orifice. Units that reflux during both resting and micturition phases had a higher incidence of DMSA abnormality than those refluxing during one phase only, but this was not statistically significant.

Vesicoureteral reflux in infants with isolated antenatal hydronephrosis

Standardized evaluation of all newborns with antenatally recognized hydronephrosis (ANH) at The Hospital for Sick Children (HSC) has included voiding cystourethrography (VCUG). This paper reviews this protocol to determine: (1) the prevalence of vesicoureteral reflux (VUR) in isolated ANH and (2) the value of performing VCUG in cases of mild hydronephrosis, defined as renal pelvis dilatation <10 mm on postnatal ultrasonography (US). A retrospective chart review was performed on infants referred with ANH. The inclusion criterion was isolated ANH. Exclusion criteria were (1) presence of additional genitourinary abnormalities and (2) no VCUG. Pelviectasis was categorized according to the anteroposterior diameter of the renal pelvis. There were 111 infants with isolated ANH. All except 3 underwent VCUG. There were 68 children (63%) with normal postnatal US or mild pelviectasis (<10 mm). VUR was detected in 16 patients, of whom 10 had mild or absent pelvic dilatation. There was no correlation between the degree of pelviectasis on postnatal US and the presence or severity of VUR ( P=0.567 and P=0.802). VUR was detected in 15% of children with isolated ANH, many of whom had normal postnatal US or mild postnatal pelviectasis. VCUG is the only reliable test for detecting postnatal VUR.

Gadolinium-Enhanced Magnetic Resonance Fluoroscopy Used as Micturating Cystourethrography

RATIONALE AND OBJECTIVE

To approach the concept of magnetic resonance (MR) imaging-monitored micturating cystourethrography (MRMCU) by using gadolinium-enhanced real-time MR fluoroscopy.

METHODS

MRMCU was performed in 21 male patients (27-76 years) subsequent to gadolinium excretory MR urography. Patients were examined in supine position at 1.5 T. For MR fluoroscopy of the urethra during micturition, we used a T1-weighted single-slice gradient-echo sequence with continuous radial k-space acquisition. Image reconstruction was obtained with the sliding-window technique reaching a frame rate of 25/s. The image plane was guided interactively through the urethra, the bladder and the ureters without stopping the scan.

RESULTS

Two patients were unable to void in supine position. With MR fluoroscopy, the flow of gadolinium-enhanced urine through the urethra was visualized in 19 patients, in 14 of whom with complete demonstration of the urethral anatomy subdivided into 5 segments. Four urethral segments were identified in 1 patient, 3 segments in 2 patients, 2 segments in 3 patients, and 1 segment in 1 patient. MRMCU demonstrated changes in the urethral anatomy and the urine flow in 2 patients with a neobladder and in 1 patient with hypertrophy of the prostate. Subject to the limitation of antegrade gadolinium application, interactive MRMCU allowed to determine whether the ureters were enhanced by gadolinium or not.

CONCLUSION

Gadolinium-enhanced MR fluoroscopy using radial k-space acquisition has achieved complete demonstration of the segmental anatomy of the urethra in 74% of the male adult patients who were able to accomplish micturition. Although MR fluoroscopy was able to visualize the gadolinium-enhanced ureters, the current data do not permit to conclude that MRMCU can demonstrate vesicoureteral reflux, especially in children.

Conventional imaging in paediatric uroradiology

OBJECTIVE

To briefly describe basic conventional imaging in paediatric uroradiology.

METHOD

The state of the art performance of standard imaging techniques (intravenous urography (IVU), voiding cystourethrography (VCU), and ultrasound (US)) is described, with emphasis on technical aspects, indications, and patient preparation such as adequate hydration. Only basic applications as used in routine clinical work are included.

RESULT AND CONCLUSION

Conventional imaging methods are irreplaceable. They cover the majority of daily clinical routine queries, with consecutive indication of more sophisticated modalities in those patients who need additional imaging for establishing the final diagnosis or outlining therapeutic options.

[Role of direct radionuclide cystography and renal study by dimercaptosuccinic acid (DMSA) in the diagnosis and follow-up of vesicoureteral reflux]

AIM

To evaluate the role of isotopic studies in the diagnosis and follow-up of vesicoureteral reflux (VUR) and to present the results of our current protocol.

MATERIAL AND METHODS

Forty three patients with VUR were retrospectively studied with a mean follow-up of 43 years (1-11 years). VUR was diagnosed by voiding cystourethrography and followed-up by direct radionuclide cystography. During the follow-up all patients were studied by means of renal DMSA scintigraphy (21 were also studied during the acute phase of febrile urinary tract infection).

RESULTS

Eighty three renal units were examined. Voiding cystourethrography was positive for VUR in 49 renal units (59%; 8 grade I, 18 grade II, 15 grade III, and 8 grade IV). During the follow-up, direct radionuclide cystography showed decrease or disappearance of VUR in 29 renal units (35%; 4 grade I, 16 grade II, 7 grade III, and 2 grade IV). DMSA studies performed during the follow-up showed cortical lesions in 17 renal units (5 with VUR grade II, 7 with grade III, and 5 grade IV). Nine of 21 patients examined by DMSA during the acute phase of febrile urinary tract infection showed cortical damage (43%), and 6 of them (67%) progressed to cortical lesion in the follow-up DMSA.

CONCLUSIONS

The present protocol allows for the correct diagnosis and control of VUR, the early detection of acute renal damage, and the control of its evolution.

The prevalence of persistent vesicoureteral reflux after 1 negative nuclear medicine cystogram

PURPOSE

Radionuclide cystography is a widely used test for the diagnosis or indication of resolution of vesicoureteral reflux. The recurrence or persistence of reflux after 1 negative radionuclide cystogram has been previously reported. We examined the value of a second radionuclide cystogram in patients who were believed to be cured on 1 previous study and tried to identify variables that could explain the false-negative result on the initial cystogram.

MATERIALS AND METHODS

The study included 85 patients with primary vesicoureteral reflux, treated conservatively between 1991 and 1996 who had 1 negative radionuclide cystogram. A repeat radionuclide cystogram was done 12 to 18 months after the negative study. Patients were divided into those with and without reflux recurrence identified, and compared in regard to sex distribution, age at presentation and reflux resolution, time between presentation and first negative radionuclide cystogram, change in reflux grade between presentation and just before resolution, side of reflux at presentation and grade before resolution. The differences between both groups were statistically analyzed.

RESULTS

Of the 85 patients 25 (29%) had reflux recurrence, including 18 (72%) with grade 2 or greater recurrent reflux and 15 (60%) with persistent reflux 12 months after the second positive radionuclide cystogram. There was no observed association between the 2 groups in any of the variables (p >0.05).

CONCLUSIONS

This study emphasizes the importance of a second negative radionuclide cystogram to indicate the absence or resolution of reflux as 1 negative cystogram alone would have missed persistent reflux in 25 of 85 patients at 1 year and 15 of 85 patients at 2. Whether absence or resolution of reflux is a variable of the disease or an unknown factor inherent in the test is unknown as there was no statistical difference in the parameters studied between our 2 groups.

Pediatric voiding cystourethrography: a pictorial guide

Voiding cystourethrography is commonly performed in children with prenatally diagnosed hydronephrosis, urinary tract infections, and voiding abnormalities. Voiding cystourethrography can be performed with many variations designed to optimize visualization of disease and minimize radiation exposure. The procedure should include assessment of the spine and pelvis; masses or opaque calculi; bladder capacity, contour, and emptying capability; presence and grade of reflux; and urethral appearance. Radiologists differ as to whether the patient should void prior to catheterization. Anteroposterior imaging of the bladder is performed during early filling; little or no imaging is necessary during intermediate filling. When bladder filling is complete, steep oblique images that are centered on the ureterovesical junction should be obtained. If reflux is observed, the ipsilateral renal fossa may be imaged prior to voiding. With a smaller than expected voiding volume, bladder refilling is recommended. Voiding around the catheter is also strongly recommended. In girls, one anteroposterior image of the urethra is usually sufficient; in boys, the entire urethra must be imaged. Steep oblique imaging is optimal. At the conclusion of voiding, each renal fossa should be imaged to detect reflux missed at fluoroscopy as well as other anomalies. Familiarity with these abnormalities and use of proper techniques will allow detection of most common pathologic conditions with very low radiation exposure.

Diagnosis of vesico-ureteric reflux

The demonstration and grading of reflux is crucial in examination and follow-up of any child with upper urinary tract infection. A variety of factors can influence the occurrence of reflux, e.g. race, genetics, state of maturation of the ureterovesical valve, diuresis, infection and bladder dysfunction, including obstruction and neurogenic disorders. Even when reflux is investigated under strictly standardized conditions, two consecutive bladder fillings frequently show different grades of reflux. Voiding cystourethrography is, to date, the only method with a generally accepted, well-defined grading of reflux. It also allows detection of intrarenal reflux and anatomical and functional information about the bladder and urethra that is unobtainable by other methods. It is therefore usually considered the method of choice. Radionuclide cystography and, possibly, contrast enhanced ultrasonography can be complementary to voiding cystourethrography, but mainly for postoperative follow-up and screening of siblings.

Should renal ultrasonography be done routinely in children with first urinary tract infection?

To reassess the impact of renal ultrasonography on the care of children with first febrile urinary tract infection (UTI) we conducted a computer search and review of medical records of (1) all children who were admitted to our hospital with first febrile urinary tract infection and underwent renal ultrasonography during a 25-month period beginning February 1, 1995, (2) all children diagnosed by ultrasound to have hydronephrosis during the same time period. Of a total of 124 patients with UTI, renal ultrasound appeared normal or showed evidence of acute pyelonephritis in 105 (84.7%), and in another nine (7.2%) it showed only minor findings. In 10 children (8.1%) ultrasound showed hydronephrosis and/or hydroureter. In eight of the latter 10, voiding cystourethrography showed vesicoureteral reflux; in one, posterior urethral valves; and in one, who had a unilateral nonobstructed dilatated system, cystography appeared normal. Except for the last patient, who was given prophylactic antibiotics and continued to have urinary tract infections, in no other case did ultrasound alone have any impact on the patient's management. Four children with both abnormal-appearing renal ultrasound and voiding cystourethrography required surgical intervention. One hundred of the 124 children had a voiding cystourethrogram. In 38 children it detected vesicoureteral reflux and, in another two, bladder abnormalities. Thirty-five of those with abnormal-appearing cystogram but without an indication for surgery were given prophylactic antibiotics. During the same 25-month period, 63 children without urinary tract infection were diagnosed by ultrasound with hydronephrosis. In 45 of them (71.4%) the urologic abnormality had already been detected by prenatal ultrasound. Fourteen of these 45 children (31.1%) required surgery, all for congenital anomalies related to obstructive uropathy. We conclude that routine renal ultrasonography in children with first urinary tract infection has negligible influence on their clinical management. This seems to be due to the recent widespread use, in industrialized countries, of maternal-fetal ultrasonography, which already detects a significant number of children with congenital obstructive uropathy prenatally. On the other hand imaging of the lower urinary tract is of high yield and contributes significantly to patient care. Therefore, whereas imaging of the lower urinary tract should continue to be done routinely in children with first urinary tract infection, renal ultrasound may be reserved for more select cases.

The office management of recurrent urinary tract infection and vesicoureteral reflux in children

Recurrent urinary tract infections (UTIs) and vesicoureteral reflux are common diagnosis' in infants and children who are referred to a urologist. Recurrent UTIs in these patients can be challenging, especially when radiographic evaluation reveals no structural abnormality. Prophylaxis and correction of voiding and bowel dysfunction are important treatment strategies. Febrile UTIs are commonly associated with reflux and should be treated aggressively to avoid renal scarring and its sequelae. Based on a comprehensive survey of the literature, long-term treatment strategies for children with reflux are now available.

Vesicoureteral reflux

The management options outlined earlier are based on the available treatment modalities; however, when a simple, successful, durable, minimally invasive method becomes available to treat vesicoureteral reflux, the approach likely will change. Endoscopic outpatient treatment of reflux has been available for about a decade. Treatment entails injection of a material into the submucosa at the refluxing ureteral orifice to bolster it, thus curing the problem. A suspension of microscopic size polytetrafluoroethylene (Teflon) particles has been used; however, its safety has been seriously questioned, as some evidence shows migration of the particles to other organ systems, including the central nervous system. More recently, cross-linked bovine collagen has been similarly used; however, it does not appear to be as durable. The use of other materials that are safe and will lead to long-term success are being studied. Chondrocytes and other nonbiologic materials, such as microspheres of bioglass and detachable balloons, are being evaluated. It is fairly certain that when a safe material is found, patients with mild to moderate reflux will be endoscopically treated upon recognition, thereby avoiding the use of long-term prophylaxis and periodic radiographic reevaluation.

Color Doppler ultrasound for evaluation of collagen implants after endoscopic injection treatment of refluxing ureters in children

To determine whether color Doppler ultrasonography (CDUS) would add to the understanding of the bladder wall after endoscopic subureteral collagen injection (SCIN), 25 patients were studied with CDUS. The kidney length and echogenicity, the volume of the collagen, the mean length of the urinary jet, the longitudinal and transverse angles, and the distance between the origin of the jet and the midline of the bladder were measured 1 day, 1 month, and 3 months after SCIN and compared to the results of micturating cystourethrograms (MCUs) performed 3 months after SCIN. The collagen was hyperechogenic compared to the bladder wall at the time of injection, and was isoechogenic 1 and 3 months after SCIN. CDUS showed the relationship between the injected collagen and the position of the ureteral orifice. The measurements of jet length, angle, and distance of the ureteral orifice from the midline did not correlate with vesicoureteral reflux assessed by MCU. Although CDUS may demonstrate the location, the size of the injected collagen implant, and its relationship to the ureteral orifice, it is as yet unable to predict vesicoureteral reflux after SCIN.