Renal scarring and vesicoureteric reflux

Vesicoureteral reflux by contrast ultrasound, comparison with voiding and retrograde urethrocystography: A prospective accuracy study

INTRODUCTION

Diagnosis of vesicoureteral reflux (VUR) plays an important role in the management and follow-up of children presenting with urinary tract infection. This study compared voiding uronosography (VUS) as a diagnostic method for the diagnosis of VUR with the "gold standard", voiding or micturating cystourethrography (MCU). The objective of the study is not only to compare the effectiveness of both methods, but also to assess the feasibility of implementing VUS technically and economically in a large tertiary radiology center in South America.

MATERIALS AND METHOD

This was a prospective accuracy study that include 41 patients (a total of 85 ureteral units) aged between 1 month and 16 years. VUS was performed in an alternative form as regular MCU, by injecting microbubble contrast solution (SonoVue©) into the bladder through an intermittent catheter and evaluating the presence of reflux with ultrasound. MCU was always performed immediately after VUS. One pediatric radiologist evaluated all VUS exams, while a second independent pediatric radiologist evaluated all MCU exams, with both blinded to each other's assessments.

RESULTS

Comparing VUS with MCU in the diagnosis of VUR, we observed a sensitivity of 92.3 % (95 % CI 74.9-99.1 %), specificity of 98.3 % (95 % CI 90.9-100 %), positive predictive value of 96.0 % (95 % CI 79.6-99.9 %), negative predictive value of 96.7 % (95 % CI 88.5-99.6 %) and a Kappa of 0.916 (0.822-1.000). When comparing the VUR grading between VUS and MCU the agreement between the two methods was high with a Kendall's Tau-b > 0.9. VUS failed to diagnose two grade 1 VUR reflux cases in teenagers while diagnosing one grade 4 VUR in a very dilated kidney-ureter unit, which was missed on MCU. VUS and MCU had similar costs when considering the price of the ultrasound contrast agent.

DISCUSSION

VUS is a reliable alternative method to MCU for the diagnosis of VUR with the advantages of not exposing the child to ionizing radiation and potentially being more accessible due to the greater availability of ultrasound equipment. Limitations to this study include the usage of a single ultrasound equipment, which limits its generalizability and not evaluating the interobserver variability.

CONCLUSION

Consideration should be given to implementing VUS for the diagnosis of VUR, particularly in centers without fluoroscopy equipment available, since the exam's performance and cost are comparable to those of the MCU.

Vesicoureteral Reflux in Children with Urinary Tract Infections in the Inpatient Setting in Taiwan

Purpose

Children with vesicoureteral reflux (VUR) are at an increased risk of recurrent urinary tract infections (UTIs). Early detection and treatment of VUR are important to prevent renal function impairment. Therefore, the aims of this study were to determine the epidemiology of VUR and to identify clinical factors associated with VUR in Taiwanese children with a first documented UTI.

Patients and Methods

We conducted this nationwide retrospective study using the Longitudinal Health Insurance Database 2010. Children ≤6 years of age who were admitted and received intravenous antibiotics for a newly diagnosed UTI were included. Multivariate logistic regression analysis was used to identify independent factors associated with VUR.

Results

Overall, 388 (10.2%) of the children had VUR. The median (interquartile range) age at diagnosis of VUR was 0.5 (0.3–1.3) years. Among the children with VUR, the age at first UTI and the age at diagnosis of VUR were significant lower in the males than in the females. Age ≤1 year at the first UTI (odds ratio (OR), 1.3; 95% confidence interval (CI): 1.0–1.7), renal agenesis and dysgenesis (OR, 4.1; 95% CI: 1.3–13.1), hydronephrosis (OR, 2.2; 95% CI: 1.7–2.9), duplex collecting system/ectopic kidney/ectopic ureter (OR, 13.0; 95% CI: 8.1–20.8), neuropathic bladder (OR, 4.7; 95% CI: 2.0–11.1) and spina bifida (OR, 5.9; 95% CI: 1.3–27.8) were independent factors for VUR.

Conclusion

The children with VUR were more likely to have small kidneys and progression to end-stage renal disease. VUR was common in the children with a UTI and who were ≤1 year of age. Clinicians should arrange ultrasound to diagnose urinary tract anomalies. Infants with urinary tract anomalies, neuropathic bladder and spina bifida should receive further voiding cystourethrography to diagnose VUR early, as this may help to prevent renal damage.

The prevalence of kidney scarring due to urinary tract infection in Iranian children: a systematic review and meta-analysis

INTRODUCTION

Urinary tract infection is one of the most common diseases in childhood, and can lead to severe complications such as renal scarring in case of lack of diagnosis and timely treatment.

OBJECTIVE

The aim of this study was to investigate the prevalence of kidney scarring caused by urinary tract infection in Iranian children by meta-analysis.

STUDY DESIGN

English -language databases including Science Direct, PubMed, Scopus, Web of Science, and Springer, and Persian -language sites including SID, Magiran, Iranmedex, and Medlib, and the Google Scholar search engine were searched by in March 2018 using MeSH keywords. The heterogeneity of studies was studied using the I2 index. Data were analyzed using STATA software, version 15.1.

RESULTS

In 18 studies, the prevalence of kidney scarring from urinary tract infections in Iranian children was 31% (95% confidence intervalCI: 22%-39%), (which was 14% in girls and 23% in boys. Also, the prevalence of kidney scar in children with urinary reflux was 47% and in children without urinary reflux was 12%. The most common symptom of the renal scar was fever in 61%, followed by urinary reflux in 45% (unilateral in 42% and bilateral in 30%). Also, the prevalence of mild, moderate, and severe reflux, respectively, was 31%, 27%, and 13%. Meta-regression also showed that the prevalence of kidney scar due to urinary tract infections had no significant relationship with the number of samples and years of research (P > 0.05).

DISCUSSION AND CONCLUSION

About one-third of Iranian children suffering from urinary tract infections had kidney scarring, so that the prevalence is lower in girls than in boys. Also, the prevalence of renal scarring in children with urinary reflux is about four times higher than that in children without urinary reflux.

Readmissions, unplanned emergency room visits, and surgical retreatment rates after anti-reflux procedures

INTRODUCTION/BACKGROUND

The choice between endoscopic injection (EI) and ureteroneocystotomy (UNC) for surgical correction of vesicoureteral reflux (VUR) is controversial.

OBJECTIVE

To compare postoperative outcomes of EI vs UNC.

STUDY DESIGN

This study reviewed linked inpatient (SID), ambulatory surgery (SASD), and emergency department (SEDD) data from five states in the United States (2007-10) to identify pediatric patients with primary VUR undergoing EI or UNC as an initial surgical intervention. Unplanned readmissions, additional procedures, and emergency room (ER) visits were extracted. Statistical analysis was performed using multivariate logistic regression using generalized estimating equation (GEE) to adjust for hospital-level clustering.

RESULTS

The study identified 2556 UNC and 1997 EI procedures. Compared with patients undergoing EI, those who underwent UNC were more likely to be younger (4.6 vs 6.0 years, P < 0.001), male (30 vs 20%, P < 0.001), and publicly insured (34 vs 29%, P < 0.001). As shown in Summary Figure, compared with EI, UNC patients had lower rates of additional anti-reflux procedures within 12 months (25 (1.0) vs 121 (6.1%), P < 0.001), but a higher rate of 30-day and 90-day readmissions and ER visits. On multivariate analysis, patients treated by UNC remained at higher odds of being readmitted (OR = 4.45; 2.69 in 30 days; 90 days, P < 0.001) and to have postoperative ER visits (OR = 3.33; 2.26 in 30 days; 90 days, P < 0.001); however, EI had significantly higher odds of repeat anti-reflux procedures in the subsequent year (OR = 7.12, P < 0.001).

DISCUSSIONS

Endoscopic injection constituted nearly half of initial anti-reflux procedures in children. However, patients treated with UNC had significantly lower odds of requiring re-treatment in the first year relative to those treated with EI. By contrast, patients treated with UNC had more than twice the odds of being readmitted or visiting an ER postoperatively. Although the available data were amongst the largest and most well validated, the major limitation was the retrospective nature of the administrative database. The practice setting may not be generalizable to states not included in the analysis.

CONCLUSIONS

Postoperative readmissions and ER visits were uncommon after any surgical intervention for VUR, but were more common among children undergoing UNC. The EI patients had a more than seven-fold increased risk of surgical re-treatment within 1 year.

Influence of Vesicoureteral Reflux and Urinary Tract Infection on Renal Growth in Children with Upper Urinary Tract Duplication

The growth of the renal parenchyma was examined in children with duplicated outflow systems, vesicoureteral reflux (VUR), urinary tract infection (UTI) and no sign of obstruction. Ten patients with reflux occurring only in the caudal system (group A) and 4 patients with reflux both to the caudal and the apical system (group B) were studied shortly after their first UTI (study 1) and then 1.5 to 9 years later (study 2). The frequency of UTI was relatively high during the follow-up period. At urography, renal length and renal area were normal in group A in studies 1 and 2. Parenchymal thickness of the apical pole (APT/L) did not differ from normal values in any of the studies. Parenchymal thickness of the caudal pole (CPT/L) was significantly smaller than normal in both studies. There was also a significant decrease in CPT/L between study 1 and 2. UTI during the first year of life was associated with a greater reduction in CPT/L. The determination of renal length and renal area in children with a duplicated ureter, VUR and UTI, does not identify subjects at risk of developing renal growth retardation while serial determinations of parenchymal thickness appear to be an appropriate method.

Open versus minimally invasive ureteroneocystostomy: A population-level analysis

INTRODUCTION

Open ureteroneocystostomy (UNC) is the gold standard for surgical correction of vesicoureteral reflux (VUR). Beyond single-center reports, there are few published data on outcomes of minimally-invasive (MIS) UNC. Our objective was to compare postoperative outcomes of open and MIS UNC using national, population-level data.

METHOD

We reviewed the 1998-2012 Nationwide Inpatient Sample to identify pediatric (≤18 years) VUR patients who underwent either open or MIS UNC. Demographics, National Surgical Quality Improvement Program (NSQIP) complications, length of stay (LOS), and cost data were extracted. Statistical analysis was performed using weighted, hierarchical multivariate logistic regression (complications) and negative binomial regression (LOS, cost).

RESULTS

We identified 780 MIS and 75,976 open UNC admissions. Compared with patients undergoing open UNC, patients who underwent MIS UNC were likely to be older (6.2 versus 4.8 years, p < 0.001), publically insured (43 versus 26%, p < 0.001), and treated in recent years (90 versus 46% after 2005, p < 0.001). MIS admissions were associated with a significantly shorter length of stay (1.0 versus 1.8 days, p < 0.001) and higher cost ($9230 versus $6,304, p = 0.002). After adjusting for patient-level confounders (age, gender, insurance, treatment year, and comorbidity), and hospital-level factors (region, bedsize, and teaching status), MIS UNC was associated with a significantly higher rate of postoperative urinary complications such as UTIs, urinary retention, and renal injury (OR 3.1, p = 0.02), shorter LOS (RR 0.8, p = 0.02), and higher cost (RR 1.4, p = 0.008).

DISCUSSION

Strengths of this study are its large cohort size, long time horizon, national estimation, and cost data. Most prior studies are case-series limited to the size of the institutional cohort. Our analysis of 76,756 operative encounters revealed that open UNC continues to be performed at far greater frequency than MIS UNC, outpacing the latter modality by nearly 100:1. Children treated with MIS UNC had three times greater odds of developing postoperative urinary complications, and MIS UNC patients incurred average costs per admission that were nearly 1.5 times higher than those of children who underwent open UNC. These children were also likely to be older, publically insured, and treated in more recent years. On the other hand, patients treated with MIS UNC required substantially shorter postoperative hospitalization, with an average LOS roughly half that of open UNC cases. Limitations include the retrospective nature of the administrative database, lack of detailed patient-level data, and no available long-term postoperative outcomes. Compared with open surgery, MIS UNC was associated with shorter LOS but higher costs and possibly higher urinary complication rates.

Estimating utility values for vesicoureteral reflux in the general public using an online tool

INTRODUCTION

Cost-utility analyses are useful to study conditions without a widely accepted treatment algorithm; in pediatric urology, one such condition is vesicoureteral reflux (VUR). A necessary component of cost-utility analyses is to accurately calculate the "utility", a numerical surrogate of quality of life, for various health states. Our aims were to determine utility values for representative VUR health states and to verify the feasibility of a novel online platform for utility elicitation in order to reduce the time and expense of such analyses.

METHODS

A cross-sectional survey of American adults was conducted using the time-trade-off (TTO) method. Respondents were recruited from an online work interface, Amazon's Mechanical Turk (MTurk). Four annualized VUR health states were assessed: VUR treated with/without continuous antibiotic prophylaxis (CAP) and with/without associated febrile urinary tract infection (UTI). A 6-week post-operative scenario following open ureteroneocystostomy was also assessed.

RESULTS

We received 278 survey responses (70% response rate). The respondents were largely between the ages of 25 and 44 (59%), female (60%), and Caucasian (76%). Thirty-seven percent had a college degree, and 44% were parents. Compared with a perfect health state of 1.0, we found mean utilities of 0.87 for VUR, regardless of whether CAP was used or whether UTI was present (p=0.9). The immediate post-operative period following ureteroneocystostomy garnered an annualized utility of 0.94.

CONCLUSIONS

Our data suggest that MTurk-based utility assessment is feasible, and that subjects view the VUR health state as only slightly inferior to perfect health. This includes VUR health states incorporating CAP and febrile UTI.

Current medical diagnosis and management of vesicoureteral reflux in children

Vesico-ureteral reflux (VUR) is presented in approximately %1 of children and is associated with an increased risk of pyelonephritis and renal scarring. Despite its prevalence and morbidity, many aspects of VUR diagnosis and treatment are controversial. We objectively assessed the published data; the data base for many current diagnoses and treatment patterns of VUR is limited. Recent studies have focused on developed determination of VUR-related renal morbidity, improved stratification tools that children would benefit most from which VUR treatment option, and improved reporting of the long-term outcomes of VUR treatments in children who are at risk for VUR. In this review, the advances in the diagnosis and treatment of VUR will be accompanied by the current guidelines.

[Primary vesicoureteral reflux treatment in childhood: comparsion of two systematic review]

Many medical practices are being carried out unawares of their efficiency, or of their actual impact on the health of the patients, therefore it is necessary to consider the support of professional recommendations with scientific evidence.

THE PRIMARY OBJECTIVE

To perform a systematic review (SR) of the therapeutic management of primary VUR in pediatric urology.

MATERIAL AND METHODS

A systematic review has been performed, including scientific evidence-based medicine criteria, of the articles published in all of the available databases. Inclusion criteria concerning basic quality of the articles were considered essential, as well as exclusion criteria to be able to reject the articles.

RESULTS AND DISCUSSION

Subsequently, and following the critic reading of greater than 320 articles, statistical study of the grouped data was performed according to the type of treatment and to the benefits contributed by each treatment, and also to their undesirable effects. Finally we have made a comparison between our results and recent Cochrane Systematic Review. The following Conclusions were drawn from the results obtained and from the analysis of the texts. Both medical and surgical treatment present with similar effectiveness concerning resolution of grades I, II and III of VUR, and the former one is the recommended initial treatment following diagnosis. Endoscopic treatment is exactly as effective as open surgery for grades I, II and III with fewer undesirable effects secondary. There are no differences concerning the efficacy of the different injected substances. Not enough evidences exist for degrees IV and V that may recommend or advise against any of the treatments. In any degree of VUR, open surgical treatment is superior as far as medical treatment is concerned only regarding the number of acute pyelonephritis episodes during followup. This conclusion cannot be applied on endoscopic treatment.

Vesicoureteric reflux in Kuwaiti children with first febrile urinary tract infection

The prevalence of vesicoureteric reflux (VUR) in children with urinary tract infection (UTI) varies among different racial groups. The purpose of this study was to determine the frequency of VUR and associated renal changes in a group of Arab Kuwaiti children with their first documented febrile UTI and to compare our findings with those reported from other racial groups. One hundred and seventy-four children (38 males and 136 females) fulfilled the study criteria and were divided into three age groups (<1 year, 1-5 years, and >5 years). Patients in each group had both micturating cystourethrography (MCUG) and 99m-Tc-dimercaptosuccinic acid (DMSA) renal scan after diagnosis. VUR was detected in 39 children (22%). Two-thirds of cases had mild reflux (grade I and II). Females ( n=32) had more reflux than males ( n=7) (24% vs. 18%). Sixty-three patients (36%) had abnormal (DMSA) renal scans (acute pyelonephritis [AP] or renal scars). Of these, 79% were children below 5 years. Abnormal DMSA scans were found in 4 of 38 males (11%) versus 59 of 136 females (43%). Abnormal scans in children with VUR were seen in 1 of 7 males (14%) versus 19 of 32 females (59%). In total, the combination of abnormal scan with VUR occurred in 1 of 38 males (3%) and in 19 of 136 females (14%), whereas abnormal scan without demonstrable VUR was seen in 3 of 38 males (8%) versus 40 of 136 females (29%). Our data showed that the frequency of VUR in Arab Kuwaiti children with febrile UTI is midway between Caucasian and other racial groups. In this study, males had a lower-risk profile than females, the latter having a higher rate of reflux as well as a higher rate of abnormal DMSA scans, irrespective of demonstrable VUR.

Vesicoureteric reflux and renal scarring in Chinese children

Vesicoureteric reflux (VUR) and renal scarring are commonly found in children with urinary tract infection (UTI). The prevalence of VUR and scarring may vary between racial groups. There are no published data on the prevalence of VUR and scarring in Chinese children with UTI. A retrospective, single-institution study was made of Hong Kong Chinese children aged less than 5 years with a documented UTI investigated by both micturating cystourethrography and dimercaptosuccinic acid scintigraphy. VUR was identified in 39% of 93 Chinese children with UTI. Renal scarring was present in 28% of boys, which is comparable with published data on Western children. Scarring appears to be less common in Chinese girls with UTI (11%) than in Western girls (30-38% from published data), and its severity is poorly related to VUR grade. There is a significant dependency relationship between grade of VUR and degree of scarring in Chinese boys (p < 0.05). In conclusion, renal scarring appears to be relatively uncommon in Chinese girls. The correlation between grade of VUR and degree of scarring in Chinese boys suggests a relationship, but provides no evidence about the direction of causation.

A 14-year follow-up of conservative treatment for vesico-ureteric reflux

OBJECTIVE

To determine renal function in patients with vesico-ureteric reflux (VUR) during 14 years of conservative treatment (no surgery).

PATIENTS AND METHODS

Sixty patients with VUR were consecutively included between 1981 and 1982. The degree of VUR was determined by conventional voiding cysto-uretherography (VCUG) after 3 months of prophylactic antibiotics. The VUR was grade I-IV, with grades III and IV characterized as high-grade VUR. In all patients, any urinary tract infections and bladder-urethral dysfunction were treated. Renal function and reflux were monitored by renal and bladder scintigraphy using 123I-hippuran and the glomerular filtration rate (GFR) was determined using the plasma clearance of 51Cr-ethylaminediamine tetra-acetic acid.

RESULTS

Of the 60 patients who entered the study, 51 were followed for a mean of 13.7 years; nine patients were lost to follow-up. None of the patients underwent antireflux surgery. All patients were in good health and normotensive (except two with borderline hypertension). Of the 51 patients 21 had low-grade, 21 unilateral high-grade and nine bilateral high-grade reflux. In those with low-grade reflux both the mean renal split function on the most refluxing kidney and the GFR remained stable during the whole monitoring period. Eighteen patients who had a persistent reduction in renal split function or initially had had a significantly reduced functional share to the most refluxing kidney had their GFR re-assessed in adolescence. However, the body surface-corrected GFR remained constant. Total GFR and single kidney GFR increased significantly.

CONCLUSION

A conservative treatment regimen in patients with VUR can ensure stable kidney function, although kidneys with a lower renal function at referral seem to have an impaired functional growth potential.

A bioassay evaluation of the urinary antibacterial efficacy of low dose prophylactic antibiotics in children with vesicoureteral reflux

PURPOSE

We evaluated by means of a bioassay the efficacy of 4 different antibiotics administered in a prophylactic dose to children with vesicoureteral reflux.

MATERIALS AND METHODS

A total of 159 urine samples from 53 children taking prophylactic antibiotics with proved vesicoureteral reflux were tested. The children were divided into 4 groups according to the antibiotic given, which included nalidixic acid, cephalexin, cotrimoxazole and cefixime. Urine samples were collected in the morning, at noon and in the evening, and each sample was bioassayed for growth inhibition of a standard Escherichia coli. The urine volume used was specifically determined for each antibiotic, and growth inhibition by this specific volume was equivalent to that produced by standard diffusion disks. In addition, the specific gravity, which reflected urinary concentration of each sample, was measured.

RESULTS

Mean patient age plus or minus standard deviation of the 4 groups was 53 +/- 41 for nalidixic acid, 23 +/- 34 for cephalexin, 55 +/- 35 for cotrimoxazole and 47 +/- 35 months for cefixime, respectively. In children less than 2 years old specific gravity was higher in the morning (1.021 +/- 0.0006 versus 1.0008 +/- 0.0004 at 8 a.m. and 2 p. m., respectively, p <0.05). In contrast, in children older than 4 years the specific gravity was higher in the afternoon and evening hours (1.019 +/- 0.003 versus 1.007 +/- 0.003 at 2 p.m. and 8 a.m., respectively, p <0.05). The percentage of patients who demonstrated growth inhibition in all 3 samples of the test day was 7%, 6%, 69% and 44% for nalidixic acid, cephalexin, cotrimoxazole and cefixime, respectively (p <0.001 for cotrimoxazole and cefixime versus nalidixic acid and cephalexin. Divided into morning, noon and evening, the percentage of samples that demonstrated growth inhibition was 85.7%, 21.4% and 7.1% for nalidixic acid, 37.5%, 12. 5% and 6.3% for cephalexin, 100%, 92.3% and 76.9% for cotrimoxazole and 100%, 77.7% and 55.5% for cefixime, respectively. A direct correlation was found between specific gravity and growth inhibition (r = 0.55, p <0.001).

CONCLUSIONS

Urine concentration during the day is dependent on age with older children having more concentrated urine in the latter part of the day. Growth inhibition is enhanced by concentrated urine. Compared to nalidixic acid and cephalexin, cotrimoxazole and cefixime produce a sustained bactericidal effect for about 60% of a 24-hour day due to the longer half-life.

Vesico-ureteric reflux and other risk factors for renal damage: identification of high- and low-risk children

This article reviews the literature with respect to various risk factors for permanent renal damage in children with urinary tract infection. Vesico-ureteric reflux is an important risk factor, but renal damage can occur in the absence of reflux. Renal damage does not always occur in the presence of gross reflux. Renal scars always develop at the same site as a previous infection in the kidney. Recurrent pyelonephritis and delay in therapy increase the likelihood of renal damage, although it is not known how long a delay is dangerous to the human kidney. Recent studies using 99mtechnetium-dimercaptosuccinic acid (DMSA) scintigraphy have not confirmed the findings of previous studies showing that children below 1 y of age are more vulnerable to renal damage. It is more likely that all children run the risk of renal scarring in cases of acute pyelonephritis. The role of bladder pressure is still not entirely understood. Therefore more studies are needed in order to determine the relationship between high voiding pressures in some, otherwise healthy, children with urinary tract infection and renal scarring. The importance of bacterial virulence in the development of renal scarring is unclear. DMSA scintigraphy and voiding cystourethrography are the most reliable tools for identifying children at risk of renal scarring. As a single method DMSA scintigraphy appears to be better than voiding cystourethrography.

Technical report: urinary tract infections in febrile infants and young children. The Urinary Tract Subcommittee of the American Academy of Pediatrics Committee on Quality Improvement

OVERVIEW

The Urinary Tract Subcommittee of the American Academy of Pediatrics Committee on Quality Improvement has analyzed alternative strategies for the diagnosis and management of urinary tract infection (UTI) in children. The target population is limited to children between 2 months and 2 years of age who are examined because of fever without an obvious cause. Diagnosis and management of UTI in this group are especially challenging for these three reasons: 1) the manifestation of UTI tends to be nonspecific, and cases may be missed easily; 2) clean voided midstream urine specimens rarely can be obtained, leaving only urine collection methods that are invasive (transurethral catheterization or bladder tap) or result in nonspecific test results (bag urine); and 3) a substantial number of infants with UTI also may have structural or functional abnormalities of the urinary tract that put them at risk for ongoing renal damage, hypertension, and end-stage renal disease (ESRD).

METHODS

To examine alternative management strategies for UTI in infants, a conceptual model of the steps in diagnosis and management of UTI was developed. The model was expanded into a decision tree. Probabilities for branch points in the decision tree were obtained by review of the literature on childhood UTI. Data were extracted on standardized forms. Cost data were obtained by literature review and from hospital billing data. The data were collated into evidence tables. Analysis of the decision tree was used to produce risk tables and incremental cost-effectiveness ratios for alternative strategies.

RESULTS

Based on the results of this analysis and, when necessary, consensus opinion, the Committee developed recommendations for the management of UTI in this population. This document provides the evidence the Subcommittee used in the development of its recommendations.

CONCLUSIONS

The Subcommittee agreed that the objective of the practice parameter would be to minimize the risk of chronic renal damage within reasonable economic constraints. Steps involved in achieving these objectives are: 1) identifying UTI; 2) short-term treatment of UTI; and 3) evaluation for urinary tract abnormalities.

Routine diagnostic imaging for childhood urinary tract infections: a systematic overview

OBJECTIVE

To assess the quality of the evidence on which current recommendations for routine diagnostic imaging for childhood urinary tract infection are based.

METHODS

A systematic overview of the literature using the MEDLINE database (1966 to October 1994), article bibliographies, and a manual search of current publications using Current Contents, was undertaken. Preset criteria were used to categorize study sample and design, and interrater reliability was assessed with a random sample.

RESULTS

A total of 434 publications were evaluated, and 63 studies met the criteria for inclusion. There was 100% interrater agreement on inclusion eligibility and design classification. No controlled trials or analytic studies evaluating routine diagnostic imaging were found. All 63 studies were descriptive, and only 10 were prospective. None of the studies provided evidence of the impact of routine imaging on the development of renal scars and clinical outcomes in children with their first urinary tract infection.

CONCLUSION

Methodologically sound, prospective studies are needed to assess whether children with their first urinary tract infection who have routine diagnostic imaging are better off than children who have imaging for specific indications. We conclude that the current recommendations are not based on firm evidence.

Resolution of vesicoureteral reflux during medical management in children

A retrospective study was performed to evaluate the results of medical management of primary vesicoureteral reflux (VUR) in infants and children. The charts of 105 patients (74 boys, 31 girls) with 167 refluxing ureters were reviewed. The age at diagnosis ranged from 3 days to 9.2 years (mean 1.3 +/- 1.9 years). The mean duration of follow-up was 2.4 +/- 1.5 years. We found that the patient's sex did not influence the fate of VUR and its complications. Patients whose reflux improved while being managed medically were younger than those who did not improve, and the younger the patient the sooner the reflux resolved. Improvement and resolution of reflux were also related to grade, and the lower the initial grading the sooner the reflux resolved. Spontaneous resolution rates of reflux were 92.3%, 76.2%, 61.7%, and 32.0% for grades I, II, III, and IV, respectively. No ureters with grade V reflux resolved without complications. The most common complications in our series were renal scarring and secondary obstructive uropathy.

Effect of prednisolone on renal scarring in rats following infection with Serratia marcescens

Renal scarring is considered a criterion of reflux nephropathy and the end stage of pyelonephritis. Prednisolone, a strong anti-inflammatory drug, at doses of 1 or 2 mg/kg prevented renal scarring in rats following infection with Serratia marcescens. Four or 8 mg/kg of prednisolone, however, did not inhibit renal scar formation. In a time course experiment, renal scarring was prevented when 4-day treatment with prednisolone was initiated 2, 5, or 13 days after infection. These results show that prednisolone is effective in preventing such scarring and suggest the clinical use of this drug for preventing renal scar formation after pyelonephritis and reflux nephropathy.

Urinary-tract infections in African neonates

During a 4-year period between January 1987 and December 1990, 41 high-risk neonates with proven urinary tract infections (UTIs) were studied prospectively and compared with 55 control neonates. An incidence of 2.6 UTIs per 1000 live births was noted, amongst whom no obvious radiological abnormalities of the urinary tract were found. Significantly, more males than females developed UTIs, the ratio being 4.5:I. Low-birth-weight babies were significantly more often affected than those of normal weight (P less than 0.05). Staphylococcus aureus and Klebsiella spp. were the predominant pathogens isolated. Aetiologically, bacteraemia from sepsis was important. Most of the infants presented with a significantly higher incidence of pyrexia, abdominal distension, lethargy and jaundice (P less than 0.01). The overall mortality rate of 17.1% was closely related to these associated problems. The relatively high incidence of UTI and the rarity of radiological abnormalities of the urinary tract in the African neonate contrast with previous reports in the literature and the reason is worthy of consideration. Despite the rarity of urinary-tract anomalies, a continuous surveillance of the trend of neonatal UTI and its outcome is recommended.

Serial 99mTc dimercaptosuccinic acid (DMSA) scans after urinary infections presenting before the age of 5 years

Forty five children presenting with a first proven urinary tract infection under the age of 5 years were studied by sequential 99mTc dimercaptosuccinic acid (DMSA) scans. Forty nine kidneys in 40 children had definite defects at presentation, and 39 (80%) of these defects were still present when the DMSA scan was repeated. Changes in the appearance of defects were independent of the presence or degree of reflux at presentation and of symptomatic recurrence of infection, though the combination of new infection and grade 3 reflux (reflux reaching the renal calices with distension) was associated with deterioration. No kidney with a relative DMSA uptake of less than 35% showed any improvement in its cortical defects. Only two kidneys that were initially without defects, in a single patient who had bilateral grade 3 reflux and breakthrough infections, developed defects on subsequent scans. The outcome after urinary tract infection is dependent on the effect of the first infection on the kidney. Occasionally children with grade 3 reflux develop damage during subsequent infections. More widespread use of DMSA scans should improve our understanding of the factors that determine the development of renal damage.

New development and progression of renal scarring in children with primary VUR

To study the development of new scars and progression of previous scarring, we analysed 711 children with primary VUR. New scar or progression of previous scarring was observed in 7.3% of the kidneys with reflux. Factors which promote the formation of new scars are high-grade VUR, recurrent UTIs and high-pressure bladder which results in high-pressure reflux. The average age of new scarring was from 7 to 9 years. We emphasize the importance of the follow-up study until the age of 15 years, even after reflux has stopped following surgery.

Renal growth and progression of reflux nephropathy in children with vesicoureteral reflux

We analyzed renal growth and development of renal scars in 754 children with primary and 169 with secondary vesicoureteral reflux. The incidence of a small kidney was 15.5 per cent in the primary and 24.1 per cent in the secondary groups. About three-fourths of the small kidneys remained small from the first examination through followup. Catch-up renal growth was only exceptional. New scars or progression of previous scarring was observed in 7.4 and 30 per cent of the primary and secondary groups, respectively. Factors that promote formation of new scars are high grade vesicoureteral reflux, recurrent urinary tract infections and abnormal bladder function that results in high pressure reflux. We emphasized the importance of precise examination of the lower urinary tract. An early antireflux operation should be performed on children with severe reflux or recurrent urinary tract infections.

99mTc dimercaptosuccinic acid (DMSA) scan as first investigation of urinary tract infection

A total of 115 children under 5 years who presented with a first symptomatic urinary tract infection and who had a 99mTc dimercaptosuccinic acid (DMSA) scan were studied to assess its value and compare the findings with those of other imaging techniques. Renal cortical defects were detected in 65 kidneys by DMSA scan, intravenous urogram, and ultrasound scan combined; 62 (95%) being seen on DMSA scan. The finding of reflux on micturating cystourethrography showed a highly significant correlation with renal defects seen on DMSA scanning, a less close but still significant correlation with abnormalities on intravenous urography, but none with ultrasound scan findings. The sensitivity of the DMSA scan in screening for all grades of reflux is estimated as 0.66, which is higher than that previously reported for the intravenous urogram or ultrasound scan. DMSA scans were less likely to miss grade 3 reflux than the other two methods. DMSA scans are more useful than other upper renal tract imaging techniques in detecting renal defects. Consideration should be given to their use as a first investigation in place of routine intravenous urograms. Ultrasound scans alone will overlook potentially serious urinary tract abnormalities.

Vesico-uretero-renal reflux and the kidney

The most frequent complications of non-obstructive vesico-uretero-renal reflux (VUR) are segmental renal scars. These scars are confined to segments with intrarenal reflux which are, in addition, exposed to bacterial infection. Primarily, only gaping collecting duct orifices, confined to compound papillae and mainly situated at the kidney poles, allow intrarenal reflux. Scar contraction and obstruction seem to be able to transform closed collecting duct orifices into gaping ones, thereby enlarging the parenchymal area prone to intrarenal reflux and to renal scarring. Contrary to earlier reports, a recent survey has documented that new scars in children develop with significant frequency beyond 5 years of age. There is a greater tendency for scarring to develop with more severe VUR, but new renal scars can develop with all grades of VUR. Early and adequate antibiotic treatment decreases the extent of scarring. The results of experimental studies in which renal scarring developed in piglets with bladder decompensation resulting from intravesical obstruction but without bacterial infection may be relevant to the few children with proximal urethral valves and hypertonic neurogenic bladders but not to the large number with non-neurogenic detrusor instability or detrusor sphincter dyssynergia. Prospective studies have not shown different recurrence rates of urinary tract infections in medically managed compared with surgically managed children. The frequency of acute pyelonephritic attacks decreased significantly after operation.

Does the severity of presentation in children with vesicoureteric reflux relate to the severity of the disease or the need for operation?

The presenting symptoms, number of previous urinary tract infections, grade of reflux and incidence of renal scarring, together with an analysis of the need for reimplantation of the ureters, were assessed retrospectively in 222 patients with vesicoureteric reflux. The grade of reflux was found to be as severe in patients presenting after a single urinary tract infection as in those presenting after more than one infection. Regardless of whether patients presented with mild, moderate or severe symptoms, the degrees of reflux and renal scarring remained similar. There was no relationship between the severity of presenting symptoms and the eventual need for ureteric reimplantation. All children should be investigated when they present for the first time with a urinary tract infection, irrespective of age, sex or severity of symptoms.

Reflux nephropathy

This article reviews current concepts of reflux nephropathy, including the pathophysiology, diagnosis, relationship to infection, role in causing end-stage renal disease, and appropriate treatment and management. The condition is defined from a epidemiologic point of view herein, and attention also is given to possible progressions this condition can take.

Enuresis as protective factor in vesicoureteral reflux

In 83 patients with non-neurologic, nonoperated vesicoureteral reflux the relation between enuresis and nephropathy was analyzed. The material showed that in spite of identical age, sex distribution, previous history of recurrent urinary tract infections, and the number of refluxing units, patients with enuresis showed a significantly lower degree of reflux nephropathy. This significant difference was even more pronounced when the age of the patients was considered. Thus patients below the age of ten showed reflux nephropathy in 25 per cent of the refluxing units in enuretic patients compared with 30.8 per cent in the nonenuretic patients. Above the age of ten 76.2 per cent of the refluxing units showed renal scarring in the nonenuretics compared with 27.8 per cent in the enuretics. The study stresses the importance of lower urinary tract malfunction in the pathogenesis of reflux. Enuresis might act as a safety valve mechanism reducing the possibility of reflux nephropathy.

Development of new renal scars: a collaborative study

In a study of the factors surrounding the development of renal scars clinical data and serial radiographs were analysed in 74 infants and children (66 girls and eight boys) without duplex kidney or obstruction. The development of new scars was seen radiologically in 87 kidneys (74 previously normal and 13 previously scarred). New scarring was extensive in 16 kidneys. Thirty four children were aged 5 or over when scarring occurred. Urinary infection occurred in all the children. Diagnosis and effective treatment were delayed in 45 of them; 58 suffered further urinary infections between the baseline intravenous urogram and the first showing new scarring. Vesicoureteric reflux was seen in 67 of the children. Investigation and treatment varied widely, and few children received long term prophylaxis. Social problems interfered with the management of 22 children. Early diagnosis, prompt effective treatment, investigation, and long term supervision of children with urinary infection are essential if renal scarring is to be reduced; those over the age of 5 are still vulnerable.

Pyelonephritic scarring in 213 patients with upper and lower urinary tract infections: long-term followup

Of 213 patients more than 3 years old with recurrent urinary tract infections new pyelonephritic scars formed only among those with a combination of urinary tract infection and vesicoureteral reflux. Of 61 patients with that combination new renal pyelonephritic scars developed in 7 (11.48 per cent) and severe clubbing in 2. Of 40 patients with vesicoureteral reflux who underwent an antireflux operation new scars formed in 5 and progressive renal damage occurred in 1. Most renal scars (58) were present at initial examination. Neither number of urinary tract infections, number of upper urinary tract infections localized by the bladder washout technique nor attacks of flank pain and fever were seen more often in patients who suffered new scars, and grade of reflux was not a factor. Patients in whom new scars developed during our prospective followup were younger than those who did not have new scars. However, new scars formed after an initial normal excretory urogram in only 1 patient with vesicoureteral reflux and urinary tract infection compared to 4 after an antireflux operation.

The many faces of vesico-ureteric reflux: factors contributing to renal damage

Current controversies in the pathogenesis and management of vesico-ureteric reflux (VUR) and reflux-associated nephropathy (RAN) are critically reviewed, together with the advantages and limitations of surgical correction of reflux. Special emphasis is given to pitfalls in diagnosis and ongoing reassessment, to the importance of associated urinary tract abnormalities, and to the need for continuing long term chemoprophylaxis in the presence of persisting VUR.

Urinary tract infection in infants with unexplained fever: a collaborative study

Nine centers collaborated to determine the rate of urinary tract infection in infants with unexplained fever, to determine whether the rate is higher in febrile infants than in asymptomatic infants, and whether the yield justifies urine cultures in febrile infants. Urine cultures were done in 501 infants 0 to 2 years of age. The rate of confirmed urinary tract infections in the 193 febrile infants was 4.1%. All infections were in girls, with a rate of 7.4%. The rate of confirmed urinary tract infections in the 312 asymptomatic infants was 0.3%; again, all infections were in girls, with a rate of 0.7%. The rate in febrile girls was significantly higher than the rate in asymptomatic girls (P less than 0.01). The data support the advisability of culturing the urine of infant girls with unexplained fever.

Influence of diuresis on the degree of vesicoureteral reflux. An experimental investigation in rats

The influence of bladder filling volume (BV), bladder pressure (BP) and diuresis (V) on the occurrence of vesicoureteral reflux (VUR) in Sprague-Dawley rats, where spontaneous VUR is common, has been investigated. The BV and BP at which VUR occurred during constant low diuresis (group I), high inconstant diuresis (group II) and moderately high, constant diuresis (group III), was measured. The abdomen was opened for visual observation of the VUR. The bladder was catheterized with a double-lumen metal catheter for infusion of a Lissamine green saline solution and to enable recording of BP. VUR occurred at significantly lower BV in group II than in group I and at significantly lower BV and BP in group I than in group III.

Prospective trial of operative versus non-operative treatment of severe vesicoureteric reflux: two years' observation in 96 children

Children with severe vesicoureteric reflux were allocated at random within three age groups (less than 1, 1-5, and greater than or equal to 6 years) to either operative or non-operative treatment. In 96 children who completed two years' observation there was no significant difference between treatment groups in either the incidence of breakthrough urinary tract infection, slope clearance of 51Cr-edetic acid, renal length, new scar formation, or progression of existing scars. Ureteric reimplantation was technically successful in 97% of cases, whereas 74% of ureters managed non-operatively still showed significant reflux at two years. No short term advantage was shown for either form of treatment in this series, but the long term effects of persistent, severe vesicoureteric reflux require further study. The prevention of reflux nephropathy probably demands the identification of vesicoureteric reflux before the advent of urinary tract infection, a goal not attainable with present invasive techniques.

Acquired renal scars in children

To determine the important factors involved in the etiology of renal scarring we studied 37 children with renal scars seen at our hospital since 1965. This is the second largest series reported to date. Children who had neurogenic bladders or any structural abnormalities of the urinary tract other than vesicoureteral reflex were excluded. The study group included 36 girls and 1 boy. The average age at first detection of renal scars was 5.7 years. Acute pyelonephritic episodes, which were treated early and aggressively, infrequently led to renal scarring. However, the initial prolonged or poorly treated episode of acute pyelonephritis was followed invariably by the development of renal scarring. The severity of renal scarring was related to the grade of vesicoureteral reflux (p less than 0.05), although some scars did develop in the absence of reflux. Neither the shape and position of the ureteral orifice nor the ureteral tunnel length correlated with the severity of renal scarring. Treatment with prophylactic antibiotics may have lessened the severity of renal scarring (0.1 less than p less than 0.2) but treatment with reimplantation surgery did not appear to alter the course of renal scarring. This study suggests that the key to the prevention of renal scarring is the early and aggressive treatment of acute pyelonephritis.

Micturition symptoms and unstable bladder activity in girls with primary vesicoureteric reflux

A series of 37 girls with primary vesicoureteric reflux of grade II and greater severity underwent urodynamic investigations. Twenty-eight (75%) were found to have unstable bladder activity. Disordered micturition patterns were common and persisted after urinary tract infections had been eradicated. Twenty-six girls had urgency of micturition and 19 urge incontinence occurring once per week or more. The correlation between these symptoms and unstable bladder activity was significant (P less than 0.01), but there was no correlation between bladder instability and the incidence of renal scarring.

A co-operative study on the clinical value of dynamic renal scanning with deconvolution analysis

An international project was set up to study the clinical usefulness of intrarenal transit times derived from the renogram by deconvolution. A common data sheet, to collect clinical, biochemical, radiological and isotopic information, was completed by the centres. Five hundred and ninety-one patients were studied and the results analysed. The mean transit time (MTT) in normal kidneys was found to be 3.6 +/- 1.1 min. If the MTT is greater than 7.6 min, a kidney is likely to be obstructed. In vesico-ureteric reflux, the transit times are prolonged, but they are normal in infection, hypertension, parenchymal disease and minimally irradiated kidneys. In transplantation, when the kidney is normal, the transit times are shorter than in the natural kidney; in acute rejection, transit time are prolonged.

Long-time effect of large vesicoureteral reflux with or without urinary tract infection

In children more than one year old the growth rate of the renal parenchyma is delayed if the kidney has a large reflux-ureter and is exposed to urinary tract infection. The growth rate of the parenchyma is normal, if the kidney has a large reflux-ureter but no infection. However, since moderate reduction of the renal parenchyma is often observed in patients with large reflux-ureter but without a history of urinary tract infection, it is concluded that a large reflux may cause back pressure injury on the kidney during infancy but, in children more than one year old, will cause renal growth retardation and renal scarring only be predisposing to pyelonephritis.

Observations on vesico-ureteric reflux and intrarenal reflux: a review and survey of material

Objectives of this study were to evaluate some of the factors influencing vesico-ureteric reflux and intrarenal reflux. Reflux occurs in about one-third to a half of Caucasian children with urinary tract infection and although not greatly influenced by examination technique or sex it is affected by age, diuretics and race. Intrarenal reflux occurs in about 10% of cases with total reflux and does not appear to cause scars on its own. Autopsy studies can provide valuable information on papillary morphology and reaction to pressure, but information is of doubtful reliability in the first months of life and in fixed specimens. The literature pertaining to vesico-ureteral reflux, intrarenal reflux and related research projects is briefly reviewed.

Reflux nephropathy

The whole subject of reflux nephropathy, which may affect 1 in every 300 of the white female population, and is the second most common disease of the kidney in the young, is still bedevilled by a lack of information regarding many of its important aspects, and the absence of any coordinated action to obtain it. What is required above all else is a means of its early detection in very young children, so that it may be prevented, at least in its more severe forms. Its financial cost can only be surmised, but the treatment of its end-stages is likely to be in the region of a hundred million dollars a year. The cost in wastage involving, as it does, young people, particularly females, is incalculable.