Commentary: the management of grades I and II (nondilating) vesicoureteral reflux

Diagnosis and management of vesicoureteral reflux in children

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

[Evaluation of renal lesions using 99mTc-DMSA in children with urinary tract infection and the relation with vesicoureteral reflux]

OBJECTIVE

Paediatric patients with urinary tract infection (UTI) have risk of developing renal scarrings. Although it is known that vesicoureteral reflux (VUR) predisposes to UTIs and it seems to have an important role in the development of renal lesions, some recent published studies question that relation. The aim of the study was to evaluate renal scarring by using renal scintigraphy 99mTc-DMSA and see the relation with or without the presence of VUR.

MATERIAL AND METHODS

We evaluated retrospectively a total of 230 patients (460 renal units), mean age: 11 months (range: 12d-5y), with UTI probed by urinoculture. All were studied with voiding cistourethrography (MCU) to evaluate the presence or absence of VUR. Patients were evaluated with 99mTc-DMSA scan 6 months after UTI to determine if UTI caused renal scarring.

RESULTS

Renal scans with 99mTc-DMSA 6 months post-infection were abnormal in 62 renal units, affecting 54 patients (23 %). From all patients studied, 110 were diagnosis of VUR being affected 161 renal units, 43 of them (27 %) presented renal scarrings. From the remaining 120 patients without VUR that is 240 renal units, 19 of them (8 %) presented parenchymatous damage.

CONCLUSION

Renal scarring resulting from UTI are in some cases related to VUR, but sometimes are caused by the infection itself. Not all patients with VUR develop renal lesions, and neither the presence of VUR always predispose children to renal lesions. MCU and direct isotopic cystography are useful for diagnosis of VUR but we shouldn't avoid 99mTc-DMSA scan in the management of children with UTI.

Vesicoureteral reflux: who benefits from surgery?

Increased recognition of the association between urinary tract infections and reflux, sibling screening, and the evaluation of antenatal hydronephrosis have resulted in an increase in the diagnosis of reflux early in life. Although many children would sustain no untoward affects of their condition if reflux were left untreated, the disease can be severe and even life threatening. Although antireflux operations have been refined and improved, it remains difficult to determine which individuals truly benefit from these operations. A large prospective randomized placebo-antibiotic-operation study with long-term follow-up is needed, as is the development of nomograms, to assess the individual child's risk of adverse outcomes.

Predictive risk factors for chronic renal failure in primary high-grade vesico-ureteric reflux

OBJECTIVE

To evaluate and define the risk factors predictive of chronic renal failure (CRF) in children with severe bilateral primary vesico-ureteric reflux (VUR), observed within the first year of life and with a long follow-up.

PATIENTS AND METHODS

The study comprised 50 patients presenting with grade 3-5 bilateral VUR diagnosed in the first year of life; 12 were suspected prenatally and confirmed shortly after birth, before any urinary tract infection (UTI). The mean (range) follow-up was 6.3 (1-16) years. The variables considered within the first year of life were: gender, prenatal diagnosis with no UTI, number of febrile UTIs, serum creatinine and urea nitrogen levels, metabolic acidosis, proteinuria, 24-h urine output, hypertension, bilateral renal length on ultrasonography and renal scarring on renal scintigraphy. CRF was defined as a creatinine clearance of <80 mL/min/1.73 m(2) at the last follow-up. The results were assessed using univariate and multivariate analyses (backward-stepwise multiple regression) of the selected variables.

RESULTS

CRF was detected at the last follow-up in 27 patients (54%), all boys, while renal function was normal in 23 (46%; seven girls). None of the 12 patients with prenatal diagnosis had UTI, but six had CRF. Febrile UTI was the presenting symptom in 38 (76%) patients and 17 (34%) of them had renal scarring. There was no significant difference between the prenatally detected VUR and febrile UTI group in the outcome as CRF. The univariate and multiple regression analysis showed that the first serum creatinine threshold of >6 mg/L before 1 year old was the most significant risk factor for CRF (P < 0.001; odds ratio 1.25).

CONCLUSIONS

Children with primary bilateral high-grade VUR and a serum creatinine of > 6 mg/L in the first year of life have a significant risk of developing CRF in the long-term. Prenatal diagnosis and postnatal febrile UTI do not modify the outcome for renal function.

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

BACKGROUND

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

OBJECTIVE

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

MATERIALS AND METHODS

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

RESULTS

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

CONCLUSIONS

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

Retrospective analysis of inflammatory parameters in acute pyelonephritis

OBJECTIVE

Different parameters were compared in children with acute pyelonephritis in order to facilitate the early detection of vesicoureteral reflux (VUR) in primary healthcare settings.

MATERIAL AND METHODS

This was a cross-sectional, hospital-based study. A total of 149 children with confirmed acute pyelonephritis were retrospectively analyzed between January 1999 and December 2000. The primary factors studied were body temperature, C-reactive protein level, white blood cell count and neutrophil ratio.

RESULTS

The study population comprised 82 males (55.0%) and 67 females (45.0%). The mean age of the patients was 2.7 +/- 3.9 years (age range 1 day to 18 years; 75% <3 years old). Of 123 patients who underwent voiding cystourethrography, 34 (27.6%) had VUR. When raised C-reactive protein, leukocytosis and raised neutrophil ratio occurred together, the specificity and positive predictive value for predicting VUR were obviously increased, but sensitivity was radically decreased. After controlling for the other covariates, multivariate logistic regression analysis showed that factors significantly related to VUR were age (odds ratio = 1.3, 95% confidence interval 1.02-1.67; p < 0.05) and raised neutrophil ratio (odds ratio = 4.2, 95% confidence interval 1.1-16.5; p < 0.05).

CONCLUSIONS

Our findings emphasize that the prevalence of VUR in children with acute pyelonephritis is extremely high. If a raised neutrophil ratio is observed, the potential risk of VUR is significantly increased in patients with clinically suspected acute pyelonephritis. Hence, the neutrophil ratio is recommended as an excellent parameter for predicting VUR.

Urinary tract infections

Urinary tract infections (UTIs) are a common infectious disease in primary care practice. This article reviews topics highlighting recent research, including UTIs in pregnancy and pediatric UTIs. The authors also discuss catheter-associated UTIs, given the large number of hospitalized patients undergoing catheterization and residents of long-term care facilities, in whom catheters are used frequently, and complicated UTIs.

Survey results on medical and surgical followup of patients with vesicoureteral reflux from American Association of Pediatrics, Section on Urology members

PURPOSE

Little data are available on the appropriate followup protocols for patients treated medically or surgically for vesicoureteral reflux. We surveyed urologists who primarily practice pediatric urology to determine current practice patterns for following patients treated for vesicoureteral reflux.

MATERIALS AND METHODS

A 1-page survey was mailed to the 225 members of the American Academy of Pediatrics, Section on Urology. The mailing roster and labels were provided by the American Academy of Pediatrics. The survey included questions on the followup of patients with low and high grade reflux treated medically or surgically. Returned surveys were blindly tabulated by 2 independent reviewers (F. A. F. and P. H. M.).

RESULTS

Of the 225 surveys 155 were returned and analyzed for an overall response rate of approximately 61%. Urine culture is routinely performed by 64% and 71% of respondents to follow children with uncorrected low grade reflux and those with high grade reflux undergoing medical treatment, respectively, generally at 3 to 6-month intervals. To follow patients with reflux voiding cystourethrography or radionuclide scan is performed yearly by 99% of study participants, while 77% perform ultrasound. Renal scan and excretory urography are done infrequently. The timing of the surgical correction of unresolved asymptomatic reflux and/or when to discontinue antibiotics in these cases varied significantly among survey respondents. After antireflux surgery 92% and 91% of respondents perform voiding cystourethrography and ultrasound, respectively. Recommended followup after ureteroneocystotomy varied greatly among survey participants.

CONCLUSIONS

The overwhelming majority of practitioners agree on the timing and type of radiographic studies to be used to follow children treated for reflux and the majority routinely perform urine culture. Opinion on the continuation of antibiotics and timing of surgical intervention for asymptomatic unresolved reflux is divided. Wide variation exists on the recommended followup after reimplantation.

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.

[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.

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.