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

Mechanism of vesicoureteral reflux: High detrusor pressure versus low ureteral resistance A narrative review

The objective of this narrative review is to deepen the understanding of vesicoureteral reflux (VUR) by exploring its historical context, current treatments and their outcomes, as well as offering an alternative perspective on this condition. VUR was first identified in patients with neurogenic bladder following spinal cord injury; it has since been linked to urinary tract infections in newborns and children. The classical theory of primary VUR is that it is caused by the short submucosal ureteral tunnel which leads to low ureteral resistance, thus leading to the development of various surgical methods to increase the ureteral resistance. However, growing evidence indicates that secondary VUR, caused by elevated detrusor pressure, may be a more common cause. Hence, it is critical to identify low urinary tract obstruction during the voiding cystourethrogram or raised detrusor pressure as the cause of the VUR before attempting surgical correction. More studies are necessary to support this position and enhance the treatment outcomes for VUR patients.

Correlation not Causation: Looking Back at the History of VUR

Vesicoureteral reflux (VUR) is a medical condition where urine flows retrograde from the bladder superiorly, and has traditionally been considered a risk factor for kidney damage in children. However, over the past decade and a half, several randomized controlled trials have shown the risk of kidney damage in the presence of VUR is low, and any treatment for VUR does not change that risk. Here, we review the history of VUR as a pathologic condition, how the interpretation of that history led to possibly overestimating the danger, and how current findings should be seen in the context of that history.

History of endoscopic treatment of vesicoureteral reflux

Since its first clinical application in 1984, the endoscopic subureteral injection of bulking agents has become an alternative to long-term antibiotic prophylaxis and open surgical intervention in the treatment of VUR in children. The 15 min day care endoscopic procedure has gained worldwide popularity in the management of VUR in children. Over the years, multiple studies have demonstrated safety and long-term efficacy of this minimally invasive outpatient procedure. Nowadays almost 90% of the surgical treatment of VUR in Sweden is done by endoscopic procedure. In the current article, our aim was to review how the endoscopic treatment of VUR developed.

Critical analysis of the outcome of primary unilateral vesicoureteral reflux in a medium volume center

Background

Vesicoureteral reflux (VUR) is a common finding in pediatric age group. Here in we explored the possible risk factors that affect the rate of resolution in patients with primary unilateral VUR under conservative treatment.

Methods

Between 2006 and 2014, we retrospectively evaluated all VUR patients and included only patients with primary unilateral VUR. Records were reviewed for patient age at diagnosis, antenatal history, patient gender, mode of presentation, side, and grade of VUR, associated hydronephrosis (HN) on renal ultrasound, presence of scarring and split function on dimercaptosuccinic acid (DMSA) scan. Clinical and radiological outcomes were assessed. Both univariate and multivariate analysis were conducted.

Results

A total of 68 patients with primary unilateral VUR were included (32 boys and 36 girls) with a mean age of 10 months (range 1–32). Antenatal HN was detected in 50% of patients. In 15 cases (22%), VUR was of high grade (IV–V). Associated HN was evident in 39 patients (57%). DMSA scans showed renal scarring in 16 patients (23%). After a mean follow-up of 7 years, VUR resolved in 49 patients (72%). Significant predictors for VUR resolution were VUR grade, DMSA split function and associated high-grade HN. High-grade HN with VUR was the only significant independent risk factor.

Conclusions

The rate of resolution in primary unilateral VUR under conservative treatment is significantly affected by VUR grade, DMSA split renal function and the presence of associated HN. Association of high-grade HN with VUR carries a low chance for spontaneous resolution.

Vesicoscopic ureteral reimplant: is there a role in the age of robotics?

Vesicoscopic ureteral reimplantation is a challenging procedure to learn but does have outcomes equivalent to standard open repair. Children objectively have less pain than after an open cross-trigonal repair. Operative times compare favorably to other forms of minimally invasive surgery.

[Primary vesicoureteral reflux]

The never ending discussion about the diagnostics and treatment of vesicoureteral reflux (VUR) now includes arguments for diagnostic nihilism as well as invasive diagnostics and therapy, which is reminiscent of the debate on prostate cancer in adulthood. The common goal of all currently competing diagnostic strategies and approaches is the prevention of renal scars by the most effective and least burdensome approach. There is a difference between acquired pyelonephritic scars with VUR (acquired reflux nephropathy) and congenital reflux nephropathy (primary dysplasia) which cannot be influenced by any therapy.The VUR can be verified by conventional radiological voiding cystourethrography (VCUG), by urosonography, radionuclide cystography or even by magnetic resonance imaging (MRI). The guidelines of the European Association of Urology/European Society for Paediatric Urology (EAU/ESPU) recommend radiological screening for VUR after the first febrile urinary tract infection. Significant risk factors in patients with VUR are recurrent urinary tract infections (UTI) and parenchymal scarring and the patients should undergo patient and risk-adapted therapy. Infants with dilating reflux have a higher risk of renal scarring than those without dilatation of the renal pelvis. Bladder dysfunction or dysfunctional elimination syndrome represents a well-known but previously neglected risk factor in combination with VUR and should be treated prior to any surgical intervention as far as is possible.Certainly not every patient with VUR needs therapy. The current treatment strategies take into account age and gender, the presence of dysplastic or pyelonephritic renal scars, the clinical symptoms, bladder dysfunction and frequency and severity of recurrent UTI as criteria for the therapy decision. The use of an antibacterial prophylaxis as well as the duration is controversially discussed. Endoscopic therapy can be a good alternative to antibacterial prophylaxis or a surveillance strategy in patients with low grade VUR. In patients with dilating VUR and given indications for surgery, endoscopic treatment can be offered. However, parents should be completely informed about the significantly lower success rate of endoscopic therapy compared to open surgical procedures. The open surgical techniques guarantee the highest success rates and should be used in patients with a dilating VUR and high risk of renal damage.

Hypertension in pediatric patients with renal scarring in association with vesicoureteral reflux

OBJECTIVE

To examine the reflux nephropathy rate and severity as well as the hypertension rate in pediatric patients with vesicoureteral reflux (VUR).

METHODS

The study included 240 patients with VUR. Renal scarring (RS) was demonstrated by renal parenchymal examination using technetium-99m-labeled dimercaptosuccinic acid (99mTc-DMSA) scintigraphy. Office measurements of arterial blood pressure and ambulatory blood pressure monitoring (ABPM) of VUR patients were done during the follow-up period.

RESULTS

Follow-up was a mean duration of 24 months. Rates of RS and hypertension increased parallel to increases in the degree of VUR. A gradual elevation in hypertension rates was evident during the follow-up period. All patients with hypertension had RS. Severe RS in 56 patients was associated with increasing blood pressure readings by 24-hour ABPM or office measurements in 19 patients (33.9%). ABPM measurements enabled us to detect additional patients compared with office measurements alone.

CONCLUSION

Hypertension is a serious complication in children with reflux nephropathy and is associated with the severity of RS and VUR grade. ABPM seems to be superior over office measurements of blood pressure in identifying patients with hypertension.

The management of urinary infections: what have we learned in the past decade?

User-friendly, cost-effective practices to manage urinary infection should become routine. The vast majority of inflections are relatively easy to treat and many of these can be prevented with appropriate interventions. Additional research is urgently needed to compare various clinical strategies and determine which is most acceptable to patients at a reasonable cost with satisfactory health outcomes.

[Therapeutic options for primary vesicoureteral reflux: endoscopic vs open surgical approach]

Therapy of vesicoureteral reflux (VUR) has steadily changed during the last decade. Open surgical procedures, e.g. extravesical reflux repair with the Lich-Gregoir technique or ureterocystoneostomy with the psoas hitch technique, reference standards with excellent success rates, are less frequently used. Since its approval by the US Food and Drug Administration (FDA) endoscopic reflux therapy with Deflux® has gained more and more popularity. However, the usage of so-called bulking agents, e.g. Deflux®, still remains controversial in dilating reflux, while its application for low-grade VUR is increasingly being accepted. Despite higher recurrence rates in all grades of VUR, the use of the "minimally invasive injection" is increasing. The question has to be answered which therapy - if necessary - benefits the patient most. Which role has the subureteral injection gained and are open surgical procedures for VUR therapy "out"?

The accuracy and health risks of a voiding cystourethrogram after a febrile urinary tract infection

OBJECTIVE

Physicians often defer obtaining a voiding cystourethrogram (VCUG) after the diagnosis of urinary tract infection (UTI) due to concerns regarding increased health risks and inflated rates of vesicoureteral reflux (VUR). This study examines the health risks and accuracy of VCUG testing after diagnosis of a febrile UTI.

PATIENTS AND METHODS

A retrospective review was conducted of children aged 0-18 years admitted to Nationwide Children's Hospital with a febrile UTI in 1995-2000. Children were divided into two cohorts - those who had a VCUG performed within 1 week of diagnosis (early VCUG cohort) and those who had a VCUG performed more than 1 week after diagnosis (late VCUG cohort). All children were followed for an additional 5 years after hospital discharge.

RESULTS

The incidence and severity of VUR were similar in patients that underwent early and late VCUG testing. Patients who underwent early VCUG testing showed no sign of worsening illness after the test was performed. During the 5-year follow up, these patients did not have higher rates of return emergency department visits or hospital readmission compared to those who received late VCUG testing.

CONCLUSIONS

The rate of VUR detection does not increase with early VCUG testing. Early VCUG testing does not lead to increased risk of bacterial dissemination or urosepsis.

Imaging the urinary tract in children with urinary tract infection

AIM

To evaluate whether ultrasonography (US) alone is sufficient in imaging the urinary tract in 1185 children with urinary tract infection (UTI).

METHODS

The reports on US and voiding cystourethrography (VCUG) were reviewed.

RESULTS

Initial US was normal in 861/1185 patients (73%). VCUG revealed abnormal findings in 285/861 (33%), of which grade III-V vesicoureteral reflux (VUR) comprised 97 cases (11%). During follow-up, VUR had resolved in 88/97 (91%) patients: in 50/57 (88%) patients without active treatment for VUR, in 27/29 (93%) with endoscopic and in 11/11 (100%) with open surgery for VUR. During follow-up, 11/97 patients (11%) had developed new renal scarring detectable in US, but no renal impairment occurred. Except for VUR, VCUG showed nonobstructive urethral valves in two infant boys with normal initial US. Thus, in 861 children with normal initial US, 40 patients with grade III-V VUR and two patients with significant nonreflux pathology may have benefited from surgical treatment, giving the total number of possibly missed pathological finding in 42/861 (4.9%) cases if VCUG had not been performed.

CONCLUSION

We suggest that children with UTI could be examined using US alone and to use VCUG only after additional indications.

Embryology and anatomy of the vesicoureteric junction with special reference to the etiology of vesicoureteral reflux

Concerning the ureterovesical junction - the region most important for the anti-reflux mechanism - there is still a lot of misunderstanding and misinterpretation with regard to normal fetal development. Data are scarce on possible causes of primary vesicoureteral reflux and on involved mechanisms of the so-called maturation process of refluxing ureteral endings. The ratio of the intravesical ureteral length to the ureteral diameter is obviously lower than assumed so far, as clearly revealed by some studies. Therefore it can be doubted that the length and course of the intravesical ureter is of sole importance in the prevention of reflux. Additionally refluxing intravesical ureteral endings present with dysplasia, atrophy, and architectural derangement of smooth muscle fibers. Besides, a pathologically increased matrix remodeling combined with deprivation of the intramural nerve supply has been confirmed. Consequently, symmetrical narrowing of the very distal ureteral smooth muscle coat creating the active valve mechanism to defend reflux is not achievable. It is apparent that primary congenital vesicoureteral reflux seems to be the result of an abnormality within the ureterovesical junction with an insufficient muscular wrap. Nature is believed to establish much more sophisticated mechanisms than the so-called passive anti-reflux mechanism. Remodeling processes within the ureterovesical junction of refluxing ureteral endings support that maturation itself is nothing else than wound or defect healing and not a restitution of a morphological normal ureterovesical junction. Lacking the nerve supply a restoration of any muscular structure can not be achieved.

Vesico-ureteric reflux: using mouse models to understand a common congenital urinary tract defect

Vesico-ureteric reflux (VUR) is a common congenital urinary tract defect in which urine flows retrogradely from the bladder to the kidneys because of an abnormally formed uretero-vesical junction. It is associated with recurrent urinary tract infections, renal hypo/dysplasia, reflux nephropathy, hypertension, and end-stage renal disease. In humans, VUR is genetically and phenotypically heterogeneous, encompassing diverse renal and urinary tract phenotypes. To understand the significance of these phenotypes, we and others have used the mouse as a model organism and this has led to the identification of new candidate genes. Through careful phenotypic analysis of these models, a new understanding of the genetics and biology of VUR is now underway.

Treatment of vesicoureteral reflux in adults by endoscopic injection

OBJECTIVES

To prospectively evaluate the efficacy of endoscopic injection in the adult population with vesicoureteral reflux (VUR). The search for VUR is a part of the standard workup of children with febrile urinary tract infections. However, VUR can present later in life and should be investigated in the case of recurrent pyelonephritis.

METHODS

From 2005 to 2009, 27 postpubertal patients (3 males and 24 females) were treated endoscopically with injection of polydimethylsiloxane (Macroplastique) in 13 or dextranomer/hyaluronic acid copolymer (Deflux) in 14 patients; 41 renal units were injected. The median age was 23 years (range 12-65). The VUR was evaluated as grade I in 5 ureters, grade II in 28, grade III in 7, and grade IV in 1. The indications for surgery were recurrent pyelonephritis in all patients, except for 1. Of the 27 patients, 5 (12%) had undergone previous ureteral surgery. The patients were followed up with renal ultrasonography and voiding cystourethrography.

RESULTS

VUR was corrected in 38 (93%) of 41 ureteral units. Of the 3 failures, 1 patient had a large Hutch diverticulum and another had previously undergone ureterocele incision. All the patients with treatment failure had been injected with dextranomer/hyaluronic acid copolymer. Thus, the success rate was 100% with polydimethylsiloxane and 87% with dextranomer/hyaluronic acid copolymer. De novo hydronephrosis appeared in 1 renal unit. The obstruction was confirmed by a mercaptoacetyltriglycine-Lasix technetium-99m scan and treated with temporary diversion using a double-J stent.

CONCLUSIONS

Endoscopic injection is an effective treatment of VUR after puberty. In cases of recurrent pyelonephritis, imaging should be mandatory to detect scars and VUR because the endoscopic treatment is simple and noninvasive and has a good success rate, comparable to that reported for children.

Vesicoureteral reflux in children with suspected and proven urinary tract infection

The aim of this study was to estimate the prevalence of vesicoureteral reflux (VUR) and clinically significant ultrasonography (US) abnormalities in a large group of children with proven and suspected urinary tract infection (UTI). The medical reports on renal US and voiding cystouretrographies (VCUG) of 2,036 children were reviewed. Renal US was performed on all children and VCUG on 1,185 children (58%). Based on the urine culture data, the UTI diagnoses were classified into five reliability classes (proven, likely, unlikely, false and no microbial data). The UTI diagnose was considered proven in 583/2036 (28.6%) and false in 145 (7.1%) cases. The prevalence of VUR was similar among those with proven and false UTI [37.4 vs. 34.8%; relative risk (RR) 1.08, 95% confidence intervals (95% CI) 0.7-1.7, P = 0.75] and decreased with increasing age (P = 0.001). Clinically significant US abnormalities occurred in 87/583 (14.9%) cases with proven UTI and significantly less often (11/145, 7.6%) in the false UTI class (RR 1.96, 95% CI 1.1-3.6, P = 0.02). Our finding supports the claim that VUR is not significantly associated to UTI and that its occurrence among children even without UTI is significantly higher than traditional estimates. This challenges the recommendations of routine VCUG after UTI.

Is antibiotic prophylaxis effective in preventing urinary tract infections in patients with vesicoureteral reflux?

The main concern in the management of children with vesicoureteral reflux (VUR) is the prevention of urinary tract infections and avoidance of renal damage. Medical management has been recommended or preferentially suggested over surgery in all but a few select clinical situations. Prophylactic antibiotics are prescribed routinely in the management of young children with radiological evidence of VUR following an episode of acute pyelonephritis. Prophylaxis is generally maintained until the VUR resolves spontaneously or is corrected surgically. Although the administration of prophylactic antibiotics has been universal in children with VUR, some authors have reported that long-term antibiotic prophylaxis does not fully prevent urinary tract infections or scarring, that antibiotic-related adverse events are known to occur, and that the incidence of pyelonephritis does not increase in spite of prophylactic antibiotic cessation. Recently, four prospective, randomized, controlled trials of antibiotic prophylaxis for preventing pyelonephritis and renal scarring were reported and some placebo-controlled, double-blind prospective studies are ongoing. The goal of this review is to evaluate the treatment of VUR using antibiotic prophylaxis, and its advantages and disadvantages based on appropriate descriptions and studies in the literature.

Controversies in the management of vesicoureteral reflux: the rationale for the RIVUR study

The current management of vesicoureteral reflux (VUR) focuses on the prevention of urinary tract infections (UTI), with curative surgery being limited to those children that fail conservative measures. This is based on the assumption that UTIs are preventable with the use of prophylatic antibiotics, leading to reduction of renal scarring, and the possibility that VUR in children can resolve spontaneously.

METHODS

Review of the recent literature has demonstrated a growing concern that antibiotic prophylaxis may not lead to prevention of UTIs. Additionally, data indicate that renal scarring may not be preventable with antibiotic prophylaxis or even surgical correction of VUR. An overview of all of the current controversies is presented in this paper.

RESULTS

Does antibiotic prophylaxis lead to reduction in UTIs in children with VUR? To address this question, the National Institutes of Health have developed a randomized placebo-controlled study of children with VUR (the RIVUR Study), identified following the development of a UTI.

CONCLUSIONS

There are far reaching consequences of the results of the RIVUR Study. If antibiotic prophylaxis does not prevent UTI in children with VUR, or lead to reduction in renal scarring, does identification of VUR provide any benefits? Perhaps appropriate treatment of UTI may be all that is necessary for preserving renal function. Final answers will have to wait until the completion of this study.

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.

P-fimbriated Escherichia coli in adults with renal scarring and pyelonephritis

The commonest organism in urinary tract infections (UTI) is Escherichia coli. Pyelonephritogenic E.coli strains possess P-fimbriae which firmly attach to uroepithelial cells by recognition of a carbohydrate structure, alpha-D-Galp-(1-4)-beta-D-Galp, which is confined within all glycosphingolipids related to the human P-blood group antigens. Several investigators have studied virulence properties of E.coli and host resistance in relation to UTI. Uroepithelial cells from children and women with recurrent UTI have an increased capacity to bind E.coli. In contrast to previous studies the present one deals with patients with renal scarring, who constitute the major risk group among patients with UTI. P-fimbriae mediated binding to uroepithelial cells was studied and the risk of recurrent UTI in patients with renal scarring was determined. Ninety per cent of the E.coli isolates from female patients with acute non-obstructive pyelonephritis in this study possess P-fimbriae (I). The fecal E.coli colonies obtained from these patients were P-fimbriated in 55% compared to 11% of the fecal E.coli colonies from healthy controls. The P-blood group distribution in 56 female patients with renal scarring and a history of febrile UTI was the same as in a control group of 39 healthy subjects (II). A history of recurrent and/or early infections did not increase the percentage of the P1 blood group phenotype. Forty-nine female patients with renal scarring were prospectively investigated for the incidence of symptomatic UTI in relation to fecal colonization with P-fimbriated E.coli (III). Fifty-three per cent of the patients had altogether 65 episodes of symptomatic UTI during the three-year follow-up (0.036 infections per month). Eight patients (16%) had nine attacks of acute pyelonephritis and 4/5 of the tested E.coli strains from these patients were P-fimbriated. No relationship was demonstrated between the presence of P-fimbriated E.coli in the fecal flora and the development of subsequent acute pyelonephritis. The binding of P-fimbriated E.coli to uroepithelial cells from 19 female patients with renal scarring was studied with the fluorescence-activated cell sorting (FACS) analysis (IV). The uroepithelial cells from the patients with renal scarring exhibited a significantly higher binding capacity (p less than 0.01) than uroepithelial cells from healthy controls. Furthermore, uroepithelial cells from the patients with renal scarring and kidney insufficiency had a higher availability of P-fimbriae receptors on their uroepithelial cells than cells obtained from patients with renal scarring and normal renal function (r = -0.75, p less than 0.001) (V).(ABSTRACT TRUNCATED AT 400 WORDS)

Has the data efflux regarding the promising outcome following injection of deflux changed the management of adult vesicoureteral reflux?

Primary vesicoureteral reflux (VUR), traditionally considered a problem of childhood, can also be detected during adulthood. However, while the concept regarding the therapeutic management of VUR in children has undergone revolutionary changes, moving from surgical to conservative approach, the optimal therapeutic approach in adult reflux is poorly addressed and is still unknown. Herein, we review clinical and therapeutic approaches of VUR in pediatric population as published throughout the years. With the introduction of Deflux injection as a minimally invasive procedure, we identify a beginning of a new trend that further extends the indications for endoscopic injections, including its introduction to adult patients as well.

Vesicoureteric reflux is not a benign condition

Renal parenchymal defects may be congenital, usually associated with dilated vesicoureteric reflux (VUR), or they may appear in previously normal kidneys and be caused by reflux nephropathy due to VUR combined with urinary tract infection (UTI). A piglet model defined that the 70% of children with VUR and vulnerable pyramids would scar rapidly with their first UTI. Because most defects are present at first imaging after a UTI, and from the lack of benefit from apparently reasonable clinical interventions, many now believe that most defects are congenital, their association with VUR being a shared dysplasia rather than causal. Consequently, guidelines now argue for less assiduous management. These conclusions ignore adult human transplant evidence, adult pig studies, and clinical anecdotes, which indicate that scars may develop in infant kidneys quicker than urine culture can confirm the diagnosis, and that reflux nephropathy has no age limit. Its rarity over 4 years suggests that most vulnerable children develop scars before then, despite all medical efforts. I argue that preventing such scarring will require better diagnosis of infant UTI, quicker treatment, reliable imaging of scars and VUR, and subsequent protection until VUR resolves. To make a difference, we need more assiduous management, not less, and cannot afford to consider VUR to be a benign condition.

Antibiotic prophylaxis in the management of vesicoureteral reflux

Antibiotic prophylaxis has been, since 1960s, one of the management options in treating vesicoureteral reflux. The purpose of this review article is to provide a concise overview of the rational for antiobiotic prophylaxis and to discuss the various agents used. Some of the current controversies regarding use of antibiotics for reflux will also be presented.

Vesico-ureteric reflux and urinary tract development in the Pax2 1Neu+/- mouse

Vesico-ureteric reflux (VUR) is a urinary tract abnormality that affects roughly one-third of patients with renal-coloboma syndrome, an autosomal dominant condition caused by a mutation in PAX2. Here, we report that a mouse model with an identical mutation, the Pax2 1Neu+/- mouse, has a 30% incidence of VUR. In VUR, urine flows retrogradely from the bladder to the ureter and is associated with urinary tract infections, hypertension, and renal failure. The propensity to reflux in the Pax2 1Neu+/- mouse is correlated with a shortened intravesical ureter that has lost its oblique angle of entry into the bladder wall compared with wild-type mice. Normally, the kidney and urinary tract develop from the ureteric bud, which grows from a predetermined position on the mesonephric duct. In Pax2 1Neu+/- mice, this position is shifted caudally while surrounding metanephric mesenchyme markers remain unaffected. Mutant offspring from crosses between Pax2 1Neu+/- and Hoxb7/GFP+/- mice have delayed union of the ureter with the bladder and delayed separation of the ureter from the mesonephric duct. These events are not caused by a change in apoptosis within the developing urinary tract. Our results provide the first evidence that VUR may arise from a delay in urinary tract maturation and an explanation for the clinical observation that VUR resolves over time in some affected children.

Antenatally detected hydronephrosis

The strategy of management of children with hydronephrosis has considerably changed as a result of the development of ultrasound techniques, allowing a prenatal detection. Hydronephrosis is defined as a dilation of the renal collecting system, and several entirely different clinical entities can be considered this general heading, whereas early detection may have a different impact depending on the entity considered. The present work aims to describe a certain number of these clinical entities, to discuss the strategic options of management that are proposed, and to evaluate the role of medical imaging, in particular the radionuclide approach. Congenital ureteropelvic junction anomaly, vesicoureteral reflux, posterior urethral valves, and duplex kidney will be successively considered. Multicystic dysplastic kidney disease, although not classified as hydronephrosis, will be mentioned because it may be mistaken for hydronephrosis.

Outcome of conservative treatment of primary vesicoureteral reflux in 87 Thai children in a single center

AIM

To evaluate the outcome of primary vesicoureteral reflux (VUR) using conservative treatment.

METHODS

Eighty-seven children with primary VUR who had been treated with a conservative medical regimen and monitored through a yearly cystogram were recruited for the study. The study was conducted at the Pediatric Nephrology Clinic in Songklanagarind Hospital, the major tertiary care center in southern Thailand. Statistical analyses using Kaplan-Meier survival curves, chi-squared test, Fisher's exact test and multivariate analysis with Cox regression were performed.

RESULTS

The study group consisted of 41 boys and 46 girls, with a total of 133 VUR. The age of the boys was significantly lower than that of the girls (P < 0.001). Resolution of the low grades (grades I-III) of VUR was significantly more frequent than that of the high grades (grades IV-V) (68/95, 72%vs 14/38, 37%; P < 0.001). Using the Kaplan-Meier survival analysis and log-rank test, the resolutions of VUR in boys versus girls, and age <1 years versus >or=1 years were not significantly different (P = 0.2252 and 0.4756, respectively). Low-grade VUR and unilateral VUR had significantly higher probabilities of resolution than high-grade VUR and bilateral VUR, respectively (P = 0.0041 and 0.0467, respectively). Multivariate Cox regression analysis indicated that among low-grade VUR, boys and unilateral VUR had significantly higher probabilities of resolution. Among the high-grade VUR, neither sex nor laterality had a significant effect on the probabilities of VUR resolution.

CONCLUSION

This study offers more evidence that children with low-grade VUR have a higher chance of reflux resolution if they are boys and have only unilateral VUR. There is still no good guide for resolution of reflux in children with high-grade VUR.

Renal and Bladder Functional Status at Diagnosis as Predictive Factors for the Outcome of Primary Vesicoureteral Reflux in Children

PURPOSE

We studied the relationship between renal and bladder functional status at diagnosis and spontaneous resolution of reflux in young children with primary vesicoureteral reflux.

MATERIALS AND METHODS

Children with grade III or greater vesicoureteral reflux were recruited for the study. At entry each patient underwent voiding cystourethrogram, renal ultrasound, isotope renogram, and natural filling and conventional filling urodynamic studies. Patients were then divided into 4 groups-group 1 had normal renal and bladder function, group 2 had abnormal renal and normal bladder function, group 3 had normal renal and abnormal bladder function, and group 4 had abnormal renal and bladder function. Correlation between renal and bladder functional status with reflux resolution at a minimum followup of 24 months was evaluated.

RESULTS

A total of 82 patients (mean age 3.8 years) were prospectively evaluated and followed. There were 18 patients (13 males and 5 females) in group 1, 19 (13 and 6) in group 2, 19 (18 and 1) in group 3 and 26 (22 and 4) in group 4. Complete resolution of vesicoureteral reflux occurred in 17 patients (94%) in group 1 and 7 (37%) in group 2. None of the patients from group 3 or group 4 achieved complete vesicoureteral reflux resolution. Reflux grade remained unchanged in 15 patients (79%) in group 3 and 20 (77%) in group 4.

CONCLUSIONS

Resolution of vesicoureteral reflux significantly correlated with renal and bladder functional status at diagnosis. Normal renal and bladder function at diagnosis is highly predictive of complete resolution of vesicoureteral reflux, whereas abnormal renal and bladder function is prognostic for persistence of reflux.

Clinical course of 735 children and adolescents with primary vesicoureteral reflux

The purpose of this retrospective cohort study was to report the clinical course of children with primary vesicoureteral reflux (VUR). Between 1970 and 2004, 735 patients were diagnosed with VUR and were systematically followed in a single tertiary renal unit. Patients were followed up for a mean time of 76 months (6 months to 411 months). The events of interest were reflux resolution, renal damage, urinary tract infection (UTI), chronic kidney disease (CKD), and hypertension. Survival analysis was performed in order to evaluate reflux resolution and CKD. Renal damage was detected at admission in 319 patients (43.4%). Continuous low-dose antibiotic prophylaxis was administered to 624 patients (91.2%); 499 (73%) patients subsequently had no UTI or fewer than three episodes. The median time of persistence of reflux according to Kaplan-Meier analysis was 38 months for grade I/II [95% confidence interval (95% CI), 33-43], 98 months for grade III (95% CI, 78.5-105), and 156 months for grade IV/V (95% CI, 122-189). Twenty patients (3%) developed hypertension. It was estimated that the probability of CKD was 5% at 10 years after diagnosis of VUR; for children diagnosed after 1990 the probability of CKD was only 2%. Renal function impairment occurred in patients with severe bilateral reflux or in patients with contralateral renal hypoplasia. There has been an improvement of prognosis for patients diagnosed in the past 15 years.

Endoscopic treatment of reflux: management pros and cons

PURPOSE OF REVIEW

The goal of this review is to contrast the issues in favor of and against the use of endoscopic injection therapy in an attempt to highlight the current state of flux and draw attention to areas that merit further research.

RECENT FINDINGS

Current publications have mostly addressed the expanding use of endoscopic injection therapy for vesicoureteral reflux treatment, generally reporting short-term success rates and endpoints. This growing body of literature is presented in the context of perceived benefits vs. disadvantages in comparison with other available treatment modalities.

SUMMARY

The management of vesicoureteral reflux has changed dramatically in the past decade, mostly because of the increasing acceptance of endoscopic injection therapy as an adequate, minimally invasive, and effective form of therapy. Recent advances in the composition of injectable materials have allowed for easier placement with a perceived favorable safety profile. In particular, dextranomer/hyaluronic acid has become the injectable material of choice, with quick acceptance and widespread use soon after its introduction in different countries. As we critically evaluate the evolving treatment options, the presented literature helps draw attention to some of the challenges we face and the need for long-term and carefully planned prospective studies to support our interventions.

Predictive factors of resolution of primary vesico-ureteric reflux: a multivariate analysis

OBJECTIVE

To identify independent factors predicting the resolution of primary vesico-ureteric reflux (VUR) in a cohort of medically managed children.

PATIENTS AND METHODS

Between 1977 and 2003, 506 children were diagnosed with VUR and were conservatively managed and prospectively followed. All of the children were maintained on antibiotic prophylaxis. Follow-up imaging consisted of voiding cysto-urethrography (VCUG) or a direct isotope cystogram at intervals of 2-3 years. The predictive factors used are based on the patient data at the time of entry in the protocol. The dependent variable was VUR resolution. The criterion for resolution was based on a single negative VCUG or direct isotope cystogram. A survival analysis identified variables significantly associated with VUR resolution. Cox's regression model was applied to identify variables independently associated with the dependent variable.

RESULTS

After adjustment, four variables remained as independent predictors of VUR resolution: nonwhite race, relative risk (95% confidence interval) of 1.5 (1.1-1.9; P = 0.009); mild grade of VUR, 3.3 (2.1-5.3; P < 0.001); absence of renal damage, 3.3 (2.4-4.5; P < 0.001); and absence of dysfunctional voiding, 2.0 (1.4-3.1; P < 0.001). For mild VUR, three variables were significantly associated: male gender, 1.7 (1.1-2.6; P = 0.012); absence of renal damage, 3.4 (1.8-6.4; P < 0.001); and unilateral VUR, 1.6 (1.1-2.3; P = 0.004). For moderate/severe VUR, three variables were significantly associated: nonwhite race, 1.7 (1.1-2.6; P = 0.01); absence of renal damage, 3.0 (2.0-4.4; P < 0.001); and absence of dysfunctional voiding, 2.8 (1.4-5.5; P = 0.004).

CONCLUSION

Few factors are amenable to intervention to modify the natural history of VUR. According to our findings, there are only two possible interventions: avoiding renal scars and managing voiding dysfunction.

Vesicoureteral reflux

Vesicoureteral reflux, the abnormal flow of urine from the bladder into the ureter, is one of the most common congenital anomalies found in children. The association of vesicoureteral reflux with urinary tract infections and renal scarring has important clinical implications. New insights into pathogenesis and new surgical techniques are changing the approach to the management of this disorder.

Acute pyelonephritis and renal scarring in Kuwaiti children: a follow-up study using 99mTc DMSA renal scintigraphy

The aim of this study was to determine the prevalence of renal scarring in a group of Kuwaiti Arab children with their first documented acute pyelonephritis (APN). Eighty-two Kuwaiti Arab children (10 males and 72 females) who had abnormal (99m)Tc DMSA renal scan findings of acute pyelonephritis were prospectively studied with the same imaging modality 6 months after treatment to identify those who developed renal scarring. A micturition cystourethrogram (MCUG) was performed for all of the children 1 month after diagnosis. Children were divided into 3 age groups (<2 years, 2-5 years and above 5 years). The follow-up DMSA renal scans 6 months after diagnosis revealed normalization of renal changes in 56% (46 patients), much improvement with residual renal abnormality in 6% (5 patients), and persistent parenchymal defects in 38% (31 patients). Vesicoureteric reflux (VUR) was found in 32% of children (26/82) and the majority were between grade I and III. Thirteen of those with VUR (50%) developed renal scars on follow-up. Fifty-three percent of the scarred kidneys (19/36) were drained by non-refluxing ureters. In this study, children older than 2 years had less VUR yet were more susceptible to APN and to the development of renal scars. Girls were more prone to developing APN and renal scarring than boys. This work shows that APN is a serious cause for renal scarring in our patients, particularly if associated with other risk factors such as recurrent infections and the female sex.

[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.

Freqüência de desaparecimento do refluxo vésico-ureteral de graus I a III em pacientes pediátricos

OBJETIVOS: avaliar a freqüência do desaparecimento do refluxo vésico-ureteral (RVU) primário de graus I a III em crianças e correlacionar com idade no diagnóstico, sexo, grau e lateralidade. MÉTODOS: estudo retrospectivo de 34 crianças com RVU diagnosticado por uretrocistografia miccional (UCM). Cinco pacientes eram meninos (mediana: um ano e seis meses) e 29 meninas (mediana: três anos) O exame controle pela UCM ou cistografia foi realizado em intervalos de 12 a 24 meses. Na análise das variáveis utilizou-se a curva de sobrevida de Kaplan-Meier. RESULTADOS: o desaparecimento do RVU ocorreu em 52,9% dos pacientes. Comparando faixas etárias não houve diferença estatística. Nos meninos o desaparecimento do RVU ocorreu na mediana de 24 meses e nas meninas, de 60 meses. Houve diferença estatística entre os sexos (p = 0,02). Houve desaparecimento do RVU em 80% dos pacientes com RVU de grau I (mediana: 25,5 meses), 66,6% de grau II (mediana: 48 meses) 40% de grau III (mediana: 60 meses); em 21% no bilateral (mediana: 48 meses) e 75% no unilateral (mediana: 28,5 meses). Houve diferença estatística entre os graus de RVU (0,02) e lateralidade (p = 0,05). CONCLUSÕES: o desaparecimento do RVU ocorreu no sexo masculino, nos graus I ou II e unilateral.

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.

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.

Guidelines for direct radionuclide cystography in children

These guidelines, which summarise the views of the Paediatric Committee of the European Association of Nuclear Medicine, provide a framework which may prove helpful to nuclear medicine teams in daily practice. They contain information on the indications, acquisition, processing and interpretation of direct radioisotope cystography in children. The guidelines should be taken in the context of "good practice" and any local/national rules which apply to nuclear medicine examinations.

The cost-effectiveness of endoscopic injection of dextranomer/hyaluronic acid copolymer for vesicoureteral reflux

PURPOSE

Vesicoureteral reflux is a risk factor for progressive renal damage associated with urinary tract infection. Mild to moderate reflux is routinely treated with long-term antibiotic prophylaxis to prevent recurrent infections and open surgical reimplantation for breakthrough infections despite antibiotic therapy. Endoscopic subureteral injection of implant material is a therapeutic alternative to long-term prophylaxis and open surgery but its widespread use in the United States has been prevented by the lack of a stable implant material. Dextranomer/hyaluronic acid copolymer has been shown to be a safe, effective and durable implant material and was recently approved in the United States. We estimate the effect on costs and cure rates of introducing endoscopic injection with dextranomer/hyaluronic acid copolymer as a treatment alternative in the United States.

MATERIALS AND METHODS

We constructed a model that mimics current clinical practice of vesicoureteral reflux treatment for 6 years, and incorporates spontaneous resolution and surgical intervention rates obtained from 2 long-term followup studies. The treatment algorithm was established using medical data from the literature, and clinical management practices from a Delphi survey of 27 pediatric urologists and nephrologists across the United States. Endoscopic injection was introduced into the model as replacement to surgery or alternative to long-term antibiotic prophylaxis. The effectiveness of dextranomer/hyaluronic acid copolymer was calculated from 140 patients (208 ureters) with grade III reflux treated in a clinical study of 221 children in Sweden.

RESULTS

With current practice, the average cost per patient in 6 years was 6,640 US dollars and 23.5% of patients continued to have reflux. Replacing open surgery with endoscopic injection led to similar cure rates (22.2% failures) but costs were reduced to 5,522 US dollars. When injection was performed after 1 year of antibiotic therapy failure rates were reduced to 8.5% but costs increased to 7,644 US dollars.

CONCLUSIONS

Our results show that a persistent approach to endoscopic surgery can be expected to result in overall success that equals or exceeds open surgery at a lower cost. This finding is particularly true if open reimplant is reserved for patients with high grade or persistent vesicoureteral reflux.

Spontaneous resolution of vesicoureteral reflux: a 15-year perspective

PURPOSE

The spontaneous resolution rate of vesicoureteral reflux is helpful for determining the need for surgical intervention and the proper followup schedule in patients on antibiotic prophylaxis. We determined the resolution rate by patient rather than by ureter and analyzed the effects of laterality, gender, age and dysfunctional voiding.

MATERIALS AND METHODS

We retrospectively reviewed the records of 179 girls and 35 boys who presented between 1981 and 1984 with urinary tract infection and were diagnosed with primary vesicoureteral reflux. Mean age at presentation was 4.2 years and median followup was 3 years. Of the patients 107 (50%) had bilateral reflux and 60 had dysfunctional voiding. In 146 children (68%) reflux spontaneously resolved during the study. Patients were categorized by the worst grade of reflux, maintained on antibiotic prophylaxis and underwent voiding cystourethrography yearly until reflux resolved. Kaplan-Meier curves were constructed to define the resolution rate.

RESULTS

Grades I to III reflux resolved at 13% yearly during the initial 5 years of followup and then at 3.5% yearly during subsequent followup. Grade IV to V reflux resolved at 5% rate yearly. Bilateral reflux resolved more slowly than unilateral reflux and it resolved more rapidly in boys than in girls. Untreated dysfunctional voiding had no effect on overall resolution.

CONCLUSIONS

Grades I to III primary vesicoureteral reflux diagnosed after urinary tract infection resolve at identical rates and significantly more rapidly than grades IV to V. Early repair of grade IV to V reflux should be considered after age 18 months.