Disappearance of vesicoureteric reflux during long-term prophylaxis of urinary tract infection in children

Outcome at 10 years of severe vesicoureteric reflux managed medically: Report of the International Reflux Study in Children

OBJECTIVE

To study the progress of vesicoureteric reflux (VUR) grade III or IV in children followed up prospectively over 10 years.

STUDY DESIGN

One hundred forty-nine children (33 boys and 116 girls) with VUR were recruited for the International Reflux Study in Children and were treated with a medical regimen and monitored by means of serial cystograms. VUR disappearance was based on negative findings on 2 consecutive cystograms.

RESULTS

At 5 years, VUR with dilatation was seen in 72 (48%) children and VUR without dilatation, in 55 (37%); 22 (15%) children had no reflux. At 10 years, VUR with dilatation was seen in 34 (23%) children and VUR without dilatation, in 37 (25%); 78 (52%) children had no reflux. Grade IV VUR persisted in 8 children. Absence of VUR was significantly associated with grade III versus grade IV VUR (P = .007), unilateral versus bilateral reflux (P = .0002), and age > or = 5 years at entry versus age < 5 years (P = .001). Neither sex nor renal scarring at entry individually affected resolution of VUR. Among 43 (29%) children with intermittent VUR, only 6 had reflux with dilatation at 10 years.

CONCLUSION

Continuing reduction in the severity of VUR in children receiving careful medical treatment was observed over 10 years. On the basis of negative findings on 2 consecutive cystograms, VUR was absent in half of the children.

Renal scars masquerading as complex masses in a patient with vesicoureteral reflux nephropathy

Vesicoureteral reflux can lead to chronic pyelonephritis, renal scarring, and renal failure. We present a case of renal scarring masquerading as bilateral, complex renal masses. A 35-year old woman who was diagnosed with vesicoureteral reflux as a child presented for evaluation of recently developed hypertension and an abnormal renal ultrasound. Her serum creatinine level was 2.5 mg/dL and she had subnephrotic-range proteinuria. A renal sonogram showed small, echogenic kidneys and bilateral complex renal masses of 3.8 (right) and 4.4 (left) cm in greatest dimensions. CT scan of the kidneys revealed slightly contrast-enhancing masses with irregular walls. Renal angiogram showed decreased blood supply to the areas coinciding with the masses consistent with renal scarring. There was no increased vascularity. This case demonstrates that renal scarring may masquerade as renal masses. A step-wise, comprehensive approach is necessary to rule out potentially malignant lesions in these patients.

Management of vesicoureteral reflux in children

Although much has been learned about the diagnosis and management of vesicoureteral reflux, several important areas of investigation remain. Because not all children with reflux are equally susceptible to renal scarring and the development of reflux nephropathy, controversy surrounds the need to evaluate all children with urinary tract infection or to continue prophylaxis in known refluxing children after a certain age. In addition to age, other factors such as sex, grade of reflux, and the presence of voiding dysfunction can all play a role. The grade of reflux as seen on the contrast voiding cystourethrogram is the best predictor of reflux resolution in large numbers of patients, but grade alone cannot predict spontaneous cessation in any one individual. Attempts at refining more quantitative imaging modalities have so far proved unsuccessful. Open ureteral reimplantation remains the standard for surgical care if surgery is necessary. Both cystoscopic and laparoscopic techniques, however, may ultimately prove to be reliable, minimally invasive approaches to definitive correction. Finally, there are data to support continued diagnosis and treatment of reflux in at-risk populations. The incidence of reflux-related morbidity in children has significantly diminished over the last three decades. A major challenge is to better identify at-risk subpopulations of children with reflux, so that not every child will require intensive, long-term medical treatment or surgery.

Conservative treatment and anti-reflux surgery in adults with vesico-ureteral reflux: effect on urinary-tract infections, renal function and loin pain in a long-term follow-up study

STUDY PURPOSE

To investigate the long-term effects in adults of conservative treatment and anti-reflux surgery for vesico-ureteral reflux on urinary-tract infections, renal function, and loin pain.

METHODS

Of 115 adult patients with vesico-ureteral reflux diagnosed between 1968 and 1984, conservative treatment was given to 46 patients (36 women) and anti-reflux surgery was performed in 57 patients (52 women). The remaining 12 patients underwent nephrectomy or heminephrectomy and were excluded from the study. The anti-reflux surgical methods used were the Politano-Leadbetter procedure in 44 patients (73 ureters) and the Hutch procedure in 19 patients (25 ureters). Six of these patients were operated on with both methods.

RESULTS

The frequency of acute pyelonephritis was significantly reduced after anti-reflux surgery (P < 0.0001) as well as after diagnosis of vesico-ureteral reflux in the group given conservative treatment (P or < 0.001). The frequency of lower-urinary-tract infections was not altered in either group. Surgery had no effect on significant albuminuria (Albustix > or = 2+) or on progressive renal functional deterioration. Forty-three patients reported recurrent loin pain at the time of diagnosis or anti-reflux surgery. Only one of the 12 patients in the conservative group, compared with 29 of the 31 patients in the anti-reflux surgery group, obtained relief from loin pain during the follow-up. Nine patients in the anti-reflux surgery group reported restitution of reduced general well-being after surgery. These patients had experienced weariness and/or headache before surgery. Vesico-ureteral reflux was eliminated more frequently (P < 0.01) in the patients operated on by the Politano-Leadbetter procedure (94%) than in those operated on by the Hutch procedure (68%).

CONCLUSIONS

Loin pain is common in adults with vesico-ureteral reflux and is effectively eliminated by anti-reflux surgery. Anti-reflux surgery should be considered in adults with vesico-ureteral reflux and very frequent acute pyelonephritic attacks only if conservative treatment has failed to alleviate these symptoms. Anti-reflux surgery is not indicated with the aim of arresting renal functional deterioration.

[Preventive treatment of urinary tract infections in the child]

Most of childhood urinary tract infections come through ascending way. Fecal microflora is the usual source of the bacterial strains. Infection facilitating factors are bacterial virulence which increase bacterial attachment to the urinary tract, adhesins and toxins, mostly studied in Escherichia coli, and host factors (receptors availability, acquired or congenital urinary tract abnormalities). Prophylactic treatment in childhood urinary tract infection is indicated in case of obstructed uropathy before surgery, vesico-ureteral reflux without surgical management, recurrent cystitis. It includes hygiene, treatment of a possible uninhibited bladder, and antimicrobial prophylaxy. Few antimicrobial agents have been studied for efficiency and long term tolerance in children. Nitrofurantoin and cotrimoxazole are the most currently used. Subinhibitory concentrations, about 20% of the curative treatment dosage of lower urinary tract infection are effective on bacterial attachment and lessen the frequency of infections. They can be given once a day in the evening.

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.

Management of pyelonephritis and upper urinary tract infections

The most frequent cause of upper urinary tract infection remains E. coli. Other organisms are found in complicated infections associated with diabetes mellitus, instrumentation, stone, and immunosuppression. The pathogenesis of acute pyelonephritis is reviewed herein, with an emphasis on the virulence factors responsible for its initiation, including urothelial adhesion by P-fimbriae of E. coli and other common factors including hemolysin and aerobactin. Renal damage does not always ensue following such infection. It is seen when toxic oxygen radicals are released during the ischemic episode and the respiratory burst of phagocytosis is marked and prolonged. These events occur when effective antibacterial treatment is delayed when the diagnosis is not made early or when socioeconomic factors prevent treatment. The scarring of chronic pyelonephritis leads to the loss of renal tissue and function and may progress to end-stage renal disease. With effective antibacterial therapy, the immune response by both T and B lymphocytes leads to antibodies that assist in bacterial eradication. Therapy must be both rapid and effective. In many instances, antibacterial agents may be used as outpatient therapy. If the Gram stain shows only gram-negative organisms and if the infection is community acquired, oral outpatient therapy with trimethoprim/sulfamethoxazole or a fluoroquinolone may suffice if the patient has no nausea. When the patient is septic, hospitalization and treatment with parenteral antibiotics are needed. Both ceftriaxone and gentamycin are cost-effective parenteral therapy because only once-daily dosing is needed. If gram-positive organisms are found, an enterococcus should be suspected, and a beta-lactam penicillin such as piperacillin or a third-generation cephalosporin such as ceftriaxone is indicated. If penicillin allergy exists, vancomycin should be used. If the patient does not improve rapidly, diagnostic studies including ultrasound and CT will assist in the diagnosis of obstruction, abscess, or emphysematous pyelonephritis. Most of these complications are now rapidly treated percutaneously, with surgical therapy following as needed. Complicated infections, such as those occurring in patients with anatomic abnormalities, stone, or immunosuppression, are often caused by organisms other than E. coli, and long-term antibacterial therapy often leads to fungal infections such as candidiasis. A recrudescence of tuberculosis is occurring, often with resistance to antituberculous drugs. The increased incidence has been associated with the immunosuppression of AIDS but is also occurring in intravenous drug users, perhaps because of poor nutrition but also owing to noncompliance with treatment. The symptoms of renal tuberculosis are usually limited to fever, frequency, urgency, and dysuria. Hematuria with sterile pyuria is the usual laboratory finding. The young urologist should remember this renal disease in the differential diagnosis of hematuria, because medical therapy can provide a cure.

Antibacterial prophylaxis in children with urinary tract infection

The aim, in conservative management of vesico-ureteric reflux by antimicrobial prophylaxis, is to prevent recurrent febrile urinary tract infections and consequent renal scarring. However, the effects of this prophylactic strategy are difficult to evaluate, since the required studies comparing children on prophylaxis with controls (without prophylaxis but under careful supervision) are lacking. Furthermore, the optimal length of prophylaxis needs to be defined. Since risk of renal scarring is believed to occur more frequently in young people, and since recurrent urinary infections mainly affect girls, the age and sex of subjects are important in the design of a prophylactic regimen. Nitrofurantoin and trimethoprim are the most common agents used for long-term, low-dose antibacterial prophylaxis. Break-through infections still result from non-compliance and from development of bacterial resistance, the latter mainly arising with trimethoprim. Few studies of prophylactic drugs are available that adequately define patient materials and include a random allocation to the different agents. Further studies of the effects of alternative prophylactic agents are called for, preferably combined with fresh insight into the ecological impact on the bowel and periurethral floras.

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.

Medical or surgical management for children with vesico-ureteric reflux?

A critical survey of the literature on treatment of children with vesico-ureteric reflux was carried out in order to create a basis for the new Swedish management policy. There are few studies that meet modern standards of scientific methodology and provide adequate patient numbers. The only large investigations that randomized patients to operative or non-operative treatment were the Birmingham Reflux Study and the International Reflux Study in Children. In these studies, long-term outcome of renal status and renal function, as well as the number of recurrent infections, were independent of treatment modality. Although pyelonephritic recurrences were less common in the surgically managed group, this did not influence appearance of renal damage. There is no evidence to indicate clear superiority of either medical or surgical management. Further studies are needed to address such questions as the optimal duration of antibacterial prophylaxis and the effect of a dilating reflux that persists into adulthood.

Quantitative nuclear cystography does not predict outcome in patients with primary vesicoureteral reflux

PURPOSE

Quantitative nuclear cystography has been advocated as a tool for determining the prognosis in children with primary vesicoureteral reflux. We reviewed our data on this technique to assess its usefulness for predicting the outcome in this population.

MATERIALS AND METHODS

We retrospectively reviewed the records of all patients with primary reflux in whom findings were positive on at least 2 nuclear cystograms at our institution between 1992 and 1997. Patients followed at least 3 years were stratified according to outcome. Unfavorable prognostic criteria included bladder volume at reflux onset 60% or less of total bladder capacity and calculated volume of reflux 2% or greater of bladder capacity.

RESULTS

Of the 107 patients in our study 63 were followed for 3 years or longer, and reflux resolved in 17, was repaired in 24 and persisted in 22. Mean patient age at latest followup, duration of followup and number of cystograms did not significantly differ among groups. Intermittent reflux in 33% of the patients followed 3 years or longer was not associated with outcome or detrusor instability. Bladder and reflux volume varied and was nonpredictive in individuals.

CONCLUSIONS

Quantitative nuclear cystography did not predict the outcome in patients followed for primary vesicoureteral reflux at a single institution for 3 years or longer. Intermittent reflux was common. These data suggest that nuclear cystography cannot be used to assess reliably the prognosis in individuals. Strong consideration should be given to using negative findings on 2 cystograms to confirm reflux resolution in patients at high risk.

Quantitative nuclear cystography does not predict outcome in patients with primary vesicoureteral reflux

PURPOSE

Quantitative nuclear cystography has been advocated as a tool for determining the prognosis in children with primary vesicoureteral reflux. We reviewed our data on this technique to assess its usefulness for predicting the outcome in this population.

MATERIALS AND METHODS

We retrospectively reviewed the records of all patients with primary reflux in whom findings were positive on at least 2 nuclear cystograms at our institution between 1992 and 1997. Patients followed at least 3 years were stratified according to outcome. Unfavorable prognostic criteria included bladder volume at reflux onset 60% or less of total bladder capacity and calculated volume of reflux 2% or greater of bladder capacity.

RESULTS

Of the 107 patients in our study 63 were followed for 3 years or longer, and reflux resolved in 17, was repaired in 24 and persisted in 22. Mean patient age at latest followup, duration of followup and number of cystograms did not significantly differ among groups. Intermittent reflux in 33% of the patients followed 3 years or longer was not associated with outcome or detrusor instability. Bladder and reflux volume varied and was nonpredictive in individuals.

CONCLUSIONS

Quantitative nuclear cystography did not predict the outcome in patients followed for primary vesicoureteral reflux at a single institution for 3 years or longer. Intermittent reflux was common. These data suggest that nuclear cystography cannot be used to assess reliably the prognosis in individuals. Strong consideration should be given to using negative findings on 2 cystograms to confirm reflux resolution in patients at high risk.

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.

Disappearance of vesicoureteral reflux in children

OBJECTIVE

To describe the disappearance of reflux in children with vesicoureteral reflux, in whom there are presently no population-based long-term studies.

DESIGN

An unselected cohort of children with reflux detected after their first known symptomatic urinary tract infection was followed up prospectively for up to 15 years.

SETTING

A single children's hospital in a distinct geographical area at which most children with symptomatic urinary tract infection were treated.

PATIENTS

Two hundred thirty children--173 girls and 57 boys--with unilateral (n=130) and bilateral (n=100) reflux. Dilated reflux (grades III-V) was found in 54 patients (23.5%). The frequency of reflux was 34% in girls and 31% in boys who were examined after urinary tract infection.

MAIN OUTCOME MEASURE

Disappearance of reflux.

RESULTS

The probability of spontaneous disappearance of reflux was estimated using Kaplan-Meier survival curves based on 164 children who underwent multiple voiding cystourethrographies. There was a marked tendency for disappearance of reflux, with 73% of children with dilated reflux having no or only grade I reflux after 10 years. Shorter persistence of reflux was found in children with undilated reflux at the initial investigation and in boys compared with girls. However, age at first investigation was not related to the rate of disappearance, and there was no difference between children with bilateral compared with unilateral reflux.

CONCLUSIONS

This study of an unselected group of children with urinary tract infection shows a favorable long-term outcome concerning disappearance of reflux. In children with dilated reflux, this tendency was more pronounced than previously reported.

Urinary tract infections in children. Epidemiology, evaluation, and management

Accurate documentation of UTIs in children is essential for proper evaluation and management. Urine cultures with multiple organisms or colony counts less than 50,000 to 100,000 CFU/ml should be considered suspect and require confirmation, particularly with clean-catch specimens. Children with well-documented UTIs should be evaluated based on their age and presenting symptoms. Infants and young children require imaging, usually with a cystogram and sonogram of the kidneys and bladder. Older girls with febrile UTIs and boys at any age should also be considered for urinary tract imaging. Renal cortical scintigraphy with 99mTc-DMSA has emerged as the imaging study of choice for acute pyelonephritis and renal scarring in children with UTIs. Treatment of UTIs in children ideally commences with culture-specific antimicrobial therapy, although treatment may be started in sick children before culture results are available. Short-course treatment (3-5 days) is sufficient for children with acute uncomplicated lower UTIs. Children with acute pyelonephritis require 10 to 14 days of antibiotics, which can be administered on an outpatient basis in older infants and children who are not toxic, as long as good compliance is expected. Patients with first-time UTIs who require imaging should be maintained on low-dose antibiotic prophylaxis until their workup is completed. Treatment of ABU does not seem necessary if the urinary tract is otherwise normal. Long-term antibiotic prophylaxis is indicated for children with frequent symptomatic recurrences of UTI and for those with known VUR. Diagnosis and treatment of underlying voiding dysfunction and constipation is an essential component of the successful management of UTIs in children.

An analysis of social and economic factors associated with followup of patients with vesicoureteral reflux

PURPOSE

Nonsurgical treatment of vesicoureteral reflux requires antibiotic prophylaxis and long-term surveillance. We examined factors that affect followup compliance and influence quality of care in these children.

MATERIALS AND METHODS

We retrospectively reviewed the records of 288 boys and 742 girls with vesicoureteral reflux.

RESULTS

Of the children treated nonsurgically for vesicoureteral reflux 34% were lost to followup and the majority (80%) were not monitored beyond the 1-year followup appointment. Older maternal age (36 years or older) was significantly associated with improved followup compliance. Paternal age, primary physician type, medical insurance type, income, education level and environment (urban, suburban or rural) were not significant.

CONCLUSIONS

Approximately a third of children treated nonsurgically for vesicoureteral reflux will be lost to followup. Only older maternal age predicts for good compliance. Preconceptions about compliance on the basis of other factors, such as socioeconomic status and primary physician type, may be incorrect. Furthermore, the notion that certain forms of medical insurance plans may help to promote followup may also be unsupported. These children would benefit from efforts to improve compliance with a medical regimen or early correction of reflux.

Postoperative medium-term follow-up of patients with bilateral, massive primary vesicorenal reflux and reduced renal function at presentation

We report the results of a medium-term follow-up study of 52 patients with bilateral, massive primary vesicorenal reflux (PVRR) with renal damage at presentation. Ten infants between 2 and 5 months of age, with a total of 19 renal units, had a temporary vesicostomy followed by ureteral reimplantation after 12-15 months; 42 patients with 81 renal units had primary ureteral reimplantation. The postoperative observation period covered 9.5 years on average (20 months - 21.5 years). The study showed that: (1) urinary specific gravity remained reduced in about 61% of patients; (2) proteinuria improved significantly, in a direct proportion to the favorable evolution of renal function; (3) the frequency of acute pyelonephritis decreased significantly from 98% to 23%. Postoperatively, 27 patients (51%) had one or more episodes of urinary tract infection (UTI) and 12 (23.0%) still had episodes of acute pyelonephritis. (4) At follow-up 7 patients (13.5%) had stable hypertension, while 3 others had unstable hypertension (19.2%); 8 had chronic renal insufficiency or end-stage renal disease. When only adolescents more than 12 years old were considered, the incidence of hypertension increased to 34.4% (10.29). (5) Some renal scarring developed despite successful antireflux surgery, and parenchymal growth, which was severely impaired prior to surgery, restarted although it remained below - 2 standard deviations from the mean. (6) In the overall series glomerular filtration rates (GFR) significantly improved after successful surgery. However, this improvement was much more evident in patients operated upon within the 1st year of life and in those who had had a temporary vesicostomy. In the subgroup of patients operated upon after 6 years of age, successful surgery had no effect on the further decline of renal function when this was already severely compromised. We conclude that early antireflux surgery or, in selected cases, temporary vesicostomy followed by ureteral reimplantation was effective in significantly improving GFR and sharply decreasing febrile UTIs in patients with massive bilateral PVRR and renal damage at presentation.

Treatment of urinary tract infection. Clinical and economic considerations

The epidemiology, clinical manifestations, natural history and management of urinary tract infection (UTI) are briefly reviewed as background to the economic considerations of diagnosis and treatment. Specific pharmacoeconomic analyses, such as cost-effectiveness and cost-benefit analyses, of UTI are not available. Analysis of the direct costs of diagnosis and treatment reveal that laboratory costs comprise the largest proportion, followed by physician consultation and pharmaceutical costs, respectively. Antimicrobial treatment has focused on acquisition cost without due regard to costs associated with method of delivery (especially with parenteral therapy), drug monitoring, complications, suboptimal therapy, drug wastage and waste disposal. These factors indicate a preference for ambulatory therapy using oral antimicrobials rather than institutional care using parenteral agents. Indirect costs, such as lost work time and quality-of-life factors, are not readily available. Evidence suggests that nosocomial UTIs add significantly to hospital costs. Studies citing the cost effectiveness of infection control programmes have often lacked detail and may have accrued benefits to the service without apportioning full costs. Future research directions include analysis of laboratory economics in relation to the clinical encounter, improved analysis of the utility and total costs of newer antimicrobials, quantifying home versus hospital treatment and improved costing of infection control programmes.

Early 99mTc dimercaptosuccinic acid (DMSA) scintigraphy in symptomatic first-time urinary tract infection

During a 2 year period, 175 children below 6 years of age (median 0.4 year) with non-obstructive symptomatic urinary tract infection were studied by 99mTc dimercaptosuccinic acid (DMSA) scintigraphy. DMSA scintigraphy was performed at a median of 10 days after the start of treatment and was abnormal in 73 children (42%), equivocal in 29 (16%) and normal in 73 (42%). Reflux was seen in 27% of all children and in 38% of the renal units that were abnormal at DMSA scintigraphy. A decreasing frequency of abnormalities at DMSA scintigraphy was seen within the first 14 days after the start of treatment. C-reactive protein and grade of reflux correlated significantly with abnormal DMSA studies. To demonstrate renal involvement in acute urinary tract infection, DMSA scintigraphy should be performed within days after the start of treatment. It is noteworthy that reflux was seen in less than half of renal units with abnormal DMSA scintigraphy.

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.

Urinary tract infections. Old and new concepts

The recommendations for evaluation and management of pediatric patients with UTIs are summarized in Table 5. These recommendations were designed to minimize the risk of kidney damage in children with UTIs based on current perceptions of the pathogenesis of renal injury. The children at greatest risk for kidney damage are the infants and young children with febrile UTIs in whom effective treatment is delayed, those with gross VUR, and those with anatomic or neurogenic urinary tract obstruction. These recommendations likely will be modified as more is learned about the pathogenesis of renal injury associated with UTIs, as new therapeutic approaches are developed, and as imaging technology improves.

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.

Long-term follow up to determine the prognostic value of imaging after urinary tract infections. Part 1: Reflux

In 3646 children with at least one confirmed urinary tract infection the prevalence of vesicoureteric reflux at presentation was correlated with progressive renal damage during follow up of not less than two and up to 16 years. Reflux was not demonstrated either at presentation or at any subsequent time in almost one half of the children who suffered progressive renal damage and was not a risk factor for progressive renal damage in boys under 1 year. It was an important risk factor in boys over 1 year and in girls of any age. The risk of progressive renal damage in children in whom micturating cystourethrography (MCU) did not reveal vesicoureteric reflux was substantially greater than in those who indirect isotope voiding study (IVS) did not show reflux. The risk of deterioration for those in whom reflux was demonstrated was similar for both techniques. This discrepancy indicates an appreciably higher false negative rate for the MCU than the IVS. Dilatation of the renal pelvis detected by ultrasound was associated with a significantly increased risk of progressive damage only when associated with reflux, but most children with progressive damage did not have a dilated collecting system at presentation.

The intravenous urogram in the detection and evaluation of renal damage following urinary tract infection

Intravenous urography (IVU) still provides the most comprehensive structural assessment of the urinary tract. In particular, the radiological renal appearances approximate closely to the morphology of the renal scarring of reflux nephropathy or chronic atrophic pyelonephritis. It also provides reproducible renal measurements for follow-up assessment of renal growth and scarring. It is now less often used for first-line investigation of the acute urinary tract infection (UTI) because the swelling accompanying acute renal involvement is less easily recognised than the areas of defective function demonstrated on 99mtechnetium-dimercaptosuccinic acid (DMSA) studies. Also IVU contributes a higher radiation dose when calculated for full IVU (dependent on the number of films exposed) and there is a slight risk of side effects from injected contrast media, reduced by using non-ionic compounds. Because of its value in confirming such a serious diagnosis as renal scarring, suspected on ultrasonography or DMSA scintigraphy, modification of the technique of IVU with adequate preparation and the use of a reduced number of films, or single films localised to the renal areas, should be considered. Expertise in the interpretation of IVU must also be maintained because of the ancillary information regarding bowel and bladder function, the spine and evidence of stones, pertinent to the management of children with UTI and renal scarring. IVU and DMSA study remain complementary investigations.

Reflux nephropathy and pregnancy

Reflux nephropathy is one of the renal diseases encountered most frequently in women of childbearing age. Patients with severe bilateral atrophy are the most likely to develop proteinuria, hypertension, focal glomerular sclerosis and progressive chronic renal failure, and those with persistent vesicoureteral reflux are the most likely to suffer recurrent pyelonephritic episodes. Often the disease is clinically latent and first manifests itself in pregnancy, mainly by urinary tract infection but also by proteinuria, hypertension, pre-eclampsia or renal failure. Pregnancy is most often successful and uneventful whenever renal function is normal or near normal and hypertension is absent at conception. Urinary tract infection accounts for frequent morbidity but rarely results in fetal mortality. By contrast, when renal function is significantly impaired, that is in patients whose plasma creatinine concentration is in excess of 0.20-0.22 mmol l-1 at conception, especially when hypertension is also present, there is clearly a high risk of fetal growth retardation or intrauterine death. Moreover, there is a striking risk of rapid worsening of renal function and hypertension, with accelerated progression towards end-stage renal failure. Thus, women with reflux nephropathy should attempt to conceive before the plasma creatinine concentration has reached 0.20 mmol l-1, and patients with values higher than these should be clearly advised of the high risk for both the pregnancy and the progression of the disease.

The significance of vesicoureteric reflux on kidney development assessed by dimercaptosuccinate renal scintigraphy

OBJECTIVE

To study the influence of vesicoureteric reflux on kidney parenchyma and renal length, and identify typical distribution patterns by dimercaptosuccinate (DMSA) renal scintigraphy.

PATIENTS AND METHODS

DMSA renal scintigraphies in 101 children (152 renal units) with vesicoureteric reflux grade 1-5 were reviewed.

RESULTS

Three main types of pathological DMSA patterns were found: (i) dysplasia; (ii) medial defect; and (iii) pole defects. In children with no history of pyelonephritis a normal distribution pattern was found in 31%, dysplasia in 23%, medial defect in 25%, pole defects in 17% and no typical pattern in 4%. In those with a history of pyelonephritis a normal distribution pattern was found in 28%, dysplasia in 24%, medial defect in 21%, pole defects in 24% and no typical pattern in 3%. A normal pattern was significantly more frequent in kidneys with reflux grade 1-2. Dysplasia was significantly more frequent in kidneys with reflux grade 4-5. In children with no history of pyelonephritis 42% of the renal units had reduced length, 8% with no other sign of pathology. The frequency of reduced kidney length at reflux grade 1-2 did not differ significantly from that at higher grades of reflux. In children with a history of pyelonephritis 52% of the renal units had reduced length, 13% with no other sign of pathology. The frequency of reduced kidney length with a normal DMSA pattern did not differ significantly from that with a pathological pattern.

CONCLUSION

The pathological DMSA distribution with vesicoureteric reflux generally conforms to one of three main patterns. Reduced kidney length is frequent even at lower grades of vesicoureteric reflux even in patients with no history of pyelonephritis, and can be the only sign of pathology.

Congenital renal damage associated with primary vesicoureteral reflux detected prenatally in male infants

To assess the course of vesicoureteral reflux, we performed cystography, renal scintigraphy, and urography in all neonates with the prenatal diagnosis of renal pelvic dilation and revealed the presence of primary reflux (grades I to V) in 27 cases. Higher grades of reflux were associated with congenital renal damage, as shown by reduced tracer uptake during scintigraphy. Reflux was diagnosed more frequently in male infants (male/female ratio, 6:1), in many of whom bladder abnormalities were found by cystography. In another group of seven infants, in whom the reflux was associated with other urologic abnormalities, there was no sex prevalence. We conclude that severe primary reflux associated with hydronephrosis usually affects male infants and may be due to abnormal embryologic development of the male urethra, and that the kidney damage is primary and not the result of urinary tract infections. This pattern differs from that of vesicoureteric reflux diagnosed at an older age, which is observed most commonly in female patients.

Recent advances in the management of vesico-ureteric reflux

Recent studies have demonstrated that both congenital hypoplasia and acquired scarring are involved in the parenchymal lesions associated with reflux nephropathy. Medical therapy can prevent symptomatic infection. While there is no proof that either medical or antireflux surgery prevents acquired scarring, paradoxically there is evidence that surgery adds no benefit to medical therapy, and that the results of medical therapy and surgical therapy are similar in children with isolated severe reflux. The group at most severe risk of renal scarring is infants and the effects of medical and surgical therapy in preventing acquired renal injury in this group have not been sufficiently investigated. On the basis of this information it has been our practice to maintain urine sterility using continuous antibiotic prophylaxis throughout infancy and early childhood. Following the development of reliable urine toilet habit and the ability to collect midstream urine specimens, antibiotics are given according to the frequency of urine infection, and weekly testing of morning urine with nitrite strips at home is used for early detection of infection and prevention of symptomatic infection. Antireflux surgery is mandatory for those children with complicated VUR (such as urinary tract obstruction) and should otherwise be reserved for those having persistent breakthrough infections in infancy and early childhood.

A long-term follow-up of surgically treated vesicoureteric reflux in girls

Ninety-six girls with surgically treated vesicoureteric reflux (VUR) operated on between 1970 and 1975 were studied to determine their post mature growth (height and weight); the incidence of hypertension; the incidence, progression, and development of new renal scars; the incidence of urinary infection; and the outcome of any pregnancies. The average age at follow-up was 20 years 2 months (range, 16 years to 25 years). The final "post mature" height was significantly greater than that of a group of controls from all regions of Great Britain; the incidence of hypertension was 4.5% and the incidence of urinary infections was 37.6%. The majority of subsequent pregnancies were uneventful but urinary infections occurred in 36.4% and 3 of the 20 infants born had VUR.

Scintigraphic evaluation of pediatric urinary tract infection

Scintigraphic evaluation of urinary tract infection, pyelonephritis, and renal scarring represents a significant portion of a clinical pediatric nuclear medicine practice. Renal scarring from recurring infection remains an important cause of end-stage renal disease and hypertension in the pediatric population. However, the clinical presentation in infants and young children is often elusive, and clinical diagnosis of upper tract involvement is frequently unreliable. As a result, diagnostic imaging has a critical role to play in the localization of infection to the lower or upper urinary tract. Radionuclide cystography and renal cortical imaging have become mainstays of this evaluation. Direct radionuclide cystography is the preferred cystographic screening technique, because it has lower radiation exposure and greater sensitivity for the detection of vesicoureteral reflux than either indirect radionuclide cystography or fluoroscopic contrast cystography. Renal cortical scintigraphy has become the standard for the detection of pyelonephritis and renal scarring. Correlation with histopathology has demonstrated a high degree of diagnostic accuracy. Acute pyelonephritis has been shown to be the necessary etiologic factor for the development of subsequent renal scarring, and the mechanism of renal injury in pyelonephritis has been extensively studied in experimental models. The ability of prompt and appropriate antibiotic therapy to dramatically reduce the incidence of subsequent scarring also has been conclusively demonstrated both clinically and in the experimental model. Vesicoureteral reflux was once thought to be a necessary prerequisite for the development of renal scarring. Although it is clear that the intrarenal reflux of infected urine will create pyelonephritis in the experimental model, the high incidence of pyelonephritis and subsequent scarring in the absence of demonstrable vesicoureteral reflux leaves the role of reflux in question. Although the role of vesicoureteral reflux is incompletely understood, its detection nevertheless remains a standard part of the patient's evaluation.

Glomerular morphometry in reflux nephropathy: functional and radiological correlations

Using computerized digitometry, we investigated the relationships between renal size, glomerular filtration rate (GFR), proteinuria, incidence of segmental and global glomerulosclerosis, glomerular size, hilar arteriolar wall thickness and hyaline deposition in renal biopsies obtained from 24 children and adolescents with reflux nephropathy, of whom only 4 were hypertensive. Age-matched controls comprised minimal-change nephrotic syndrome (6) and recurrent haematuria with normal biopsy (13). The mean sectional area of patients' glomeruli was double that of controls. Glomerular size correlated with the amount of proteinuria (measured as protein/creatinine ratios in early morning urine) and inversely with renal size and GFR. Segmental sclerosis, invariably of hilar origin, was observed in 8 patients and the percentage of glomeruli affected correlated strongly with glomerular size and proteinuria. Global sclerosis was found equally in patients and controls, and showed no similar correlations. Compared with controls, patients' hilar arterioles showed increased wall thickness, more intramural hyaline deposits and decreased luminal diameter when related to glomerular size. The proteinuria and glomerular changes are consistent with hyperfiltration, while the previously undescribed hilar vascular changes, which both precede and accompany sclerosis, resemble abnormalities reported experimentally following renal ablation.

Results of a randomized clinical trial of medical versus surgical management of infants and children with grades III and IV primary vesicoureteral reflux (United States). The International Reflux Study in Children

A total of 132 infants and children with grades III and IV primary vesicoureteral reflux was entered into a prospective trial comparing medical to surgical management. Inclusion criteria were an age not exceeding 10 years and a glomerular filtration rate of at least 70 ml. per minute per 1.73 m.2. Children with significant urinary tract malformations and clinical signs/symptoms of dysfunctional voiding were not accepted into the trial. Medical therapy consisted of continuous low dose antibiotic prophylaxis until vesicoureteral reflux resolved. The type of surgical procedure used for the correction of reflux was left to the discretion of the surgeon. Outcome variables included the appearance or progression of renal lesions, rate of renal growth, recurrence rate of urinary tract infection or pyelonephritis, changes in total kidney glomerular filtration rate, development of hypertension and resolution rate of vesicoureteral reflux. Followup at 6, 18, 36 and 54 months after entry included, in addition to history and physical examination, voiding cystourethrography, excretory urography and a urine culture. Of the patients 68 were allocated to the medical group and 64 to the surgical group. They were stratified for age, sex and preexisting renal scarring. Of the patients 10% were boys, 47% were between 2 and 6 years old at entry, 93% had a history of pyelonephritis, 67% had either scarring or thinning of the parenchyma at entry, 87% had grade IV vesicoureteral reflux in at least 1 unit and 56% had bilateral reflux. There were no significant differences in the frequency distribution of entry characteristics between the patients allocated to either group. New renal scarring developed in 22% of medical and 31% of surgical patients (p < 0.4). Growth of kidneys with grade IV vesicoureteral reflux was slightly less than normal in the medical (-0.67 +/- 0.15 standard deviation) and surgical (-0.42 +/- 0.11 standard deviation) groups (p < 0.7). Pyelonephritis occurred in 15 medical patients versus 5 surgical patients (p < 0.05). There was no significant change in glomerular filtration rate within each treatment group and no difference in glomerular filtration rate between groups. No patient had hypertension during the followup period. The disappearance rate of vesicoureteral reflux in patients with grade IV reflux was approximately 8% per year. Of the medical patients 75% still had vesicoureteral reflux after 3 years of observation.(ABSTRACT TRUNCATED AT 400 WORDS)