Pronounced detrusor hypercontractility in infants with gross bilateral reflux

[Place of surgery for vesico-ureteral reflux in paediatric setting]

Surgical indications for vesico-ureteral reflux have become more selective and endoscopic treatment has now become part of therapeutic arsenal. However, it is important to know when to operate with uretero-vesical replantation if the ureters are severely dilated, before the acute pyelonephritis becomes recurrent in the setting of persisting reflux in girls or higher grade reflux.

Bladder function in infants

The purpose with the present review was to describe what could be considered as normal urodynamic findings in neonates and infants. During the first months of life, urodynamics were characterised by small bladder capacity and high voiding pressure levels, the latter especially marked in male infants. Also dyscoordination at voiding was a common finding. However, detrusor overactivity (unstable contractions) during filling was uncommon in infants. Towards the end of infancy, findings became more in accordance with what is seen in older children. Concluding these findings concerning urodynamic pattern in early infancy high voiding pressure levels must be looked upon as normal and the same is true for intermittent increase in activity in the pelvic floor during voiding. However, instability during filling is rarely seen.

Bladder dysfunction and vesicoureteral reflux

In this overview the influence of functional bladder disturbances and of its treatment on the resolution of vesicoureteral reflux (VUR) in children is discussed. Historically both bladder dysfunction entities, the overactive bladder (OAB) and the dysfunctional voiding (DV), have been described in conjunction with VUR. Treatment of the dysfunction was also considered to influence spontaneous resolution in a positive way. During the last decades, however, papers have been published which could not support these results. Regarding the OAB, a prospective study with treatment of the bladder overactivity with anticholinergics, did not influence spontaneous resolution rate in children with a dysfunction including also the voiding phase, DV and DES (dysfunctional elimination syndrome), most studies indicate a negative influence on the resolution rate of VUR in children, both before and after the age for bladder control, both with and without treatment. However, a couple of uncontrolled studies indicate that there is a high short-term resolution rate after treatment with flow biofeedback. It should be emphasized that the voiding phase dysfunctions (DV and DES) are more severe than the genuine filling phase dysfunction (OAB), with an increased frequency of UTI and renal damage in the former groups. To be able to answer the question if treatment of bladder dysfunction influence the resolution rate of VUR in children, randomized controlled studies must be performed.

Urine Flow Curve Shapes in Adults with Earlier Vesicoureteral Reflux

OBJECTIVES AND METHODS

Voiding problems related to childhood vesicoureteral reflux (VUR) in a cohort of 120 patients (109 females, 11 males) were studied at early middle age (range, 33-50 yr). Forty-four patients had been operated on. The study included an interview by means of a symptom questionnaire, a urine flow measurement, a residual urine measurement, and a urine sample.

RESULTS

The flow curve shape was abnormal in 40% (tower-shaped in 7%, weak in 18%, interrupted in 8%, and big bladder in 8% of patients). Forty-five percent of operated patients and 70% of nonoperated patients had a normal flow curve shape. Almost half of the operated patients (45%) had either an interrupted or a weak flow. Figures for stress incontinence and urgency incontinence among the female patients were twice those in the controls, 35% versus 16% (p=0.05) and 20% versus 11%, respectively. Urinary tract infections (UTIs) were diagnosed in 76% of the adult female VUR patients and in 57% of their controls (p=0.041). Twenty-five percent of the female VUR patients (none of the controls) reported suffering from UTI more often than once a year.

CONCLUSIONS

Adult patients with childhood VUR have abnormal urine flow curve shapes and UTIs significantly more often than controls (p=0.00005 and p=0.04, respectively). Patients who were operated on for VUR especially seemed to have an interrupted or weak flow curve shape. A high percentage of these patients also suffered from urgency and stress incontinence and annual UTIs.

Bladder dynamics and vesicoureteral reflux: factors associated with idiopathic lower urinary tract dysfunction in children

PURPOSE

The objective of this study was to determine the clinical, demographic, urodynamic and prognostic characteristics related to vesicoureteral reflux among patients with idiopathic lower urinary tract dysfunction.

MATERIALS AND METHODS

We retrospectively reviewed the records of 348 children with idiopathic detrusor overactivity or dysfunctional voiding who had been examined for vesicoureteral reflux between 1995 and 2005 at a university hospital. Demographic, clinical and urodynamic parameters were compared between groups according to the presence, grade, laterality and resolution of vesicoureteral reflux.

RESULTS

Among the 348 patients 8 infants were excluded from statistical analysis and are discussed separately. Among the 340 remaining patients 1 year and older vesicoureteral reflux was documented in 155 (46%), of whom 32% had bilateral reflux. Of the overall cases 60% were grade III or higher. Mean age in the refluxing group (6.5 +/- 2.8 years) was significantly lower than in the nonrefluxing group (7.6 +/- 2.5 years, p <0.001). Continent children presented with a significantly higher rate of vesicoureteral reflux compared to incontinent children (74% vs 42%, p <0.001). Among the patients who had urinary tract infection the presence of reflux increased the rate of renal cortical abnormalities (45% vs 17%, p <0.001). However, among patients who were free of urinary tract infection the presence of reflux was not associated with cortical abnormalities (25% vs 24%, p >0.05). Median maximum filling pressure was higher in the refluxing group compared to the nonrefluxing group (40.0 vs 34.0 cm H(2)O, p <0.001). Detrusor overactivity and dysfunctional voiding showed similar rates for development of vesicoureteral reflux. Reflux was resolved with medical treatment in 40% of the patients. The resolution rate was significantly higher in children with nondilating reflux and initial lower median cystometric bladder capacity.

CONCLUSIONS

Vesicoureteral reflux is associated with daytime incontinence, urinary tract infection, younger age and renal cortical abnormalities among patients with idiopathic lower urinary tract dysfunction. Increased intravesical pressures seem to be the primary factor for inducing reflux in idiopathic lower urinary tract dysfunction. Initial bladder capacity predicts the resolution of reflux.

Spontaneous resolution rates of vesicoureteral reflux in Brazilian children: a 30-year experience

OBJECTIVE

We evaluated clinical characteristics of primary vesicoureteral reflux (VUR) in infants in a 30-year period in Brazil with special reference to the relation of renal parenchymal damage to urinary tract infection and gender.

MATERIALS AND METHODS

From 1975 through 2005, 417 girls (81.6%) and 94 boys (18.4%) with all grades of reflux were retrospectively reviewed. Patients were categorized by the worst grade of reflux, maintained on antibiotic prophylaxis and underwent yearly voiding cystourethrography until the reflux was resolved. VUR was considered resolved when a follow-up cystogram demonstrated no reflux. Surgical correction was recommended for those who fail medical therapy, severe renal scarring or persistent VUR.

RESULTS

Grades I to V VUR resolved in 87.5%, 77.6%, 52.8%, 12.2% and 4.3%, respectively. Renal scars were present at presentation in 98 patients (19.2%). Neither gender nor bilaterality versus unilaterality was a helpful predictor of resolution. The significant difference was found among the curves using the log rank (p<0.001) or Wilcoxon (p<0.001) test.

CONCLUSION

Despite the current use of screening prenatal ultrasound, many infants are still diagnosed as having vesicoureteral reflux only after the occurrence of urinary tract infection in our country. Scarring may be associated to any reflux grade and it may be initially diagnosed at any age but half of the scars are noted with higher grades of reflux (IV and V). The incidence of reflux related morbidity in children has significantly diminished over the last three decades.

Correlation between ultrasonographic bladder measurements and urodynamic findings in children with recurrent urinary tract infection

OBJECTIVE

To evaluate the role of bladder variables measured by ultrasonography (US) in assessing bladder dysfunction in children with urinary tract infections (UTIs).

PATIENTS AND METHODS

Children presenting with recurrent UTI (with or with no vesico-ureteric reflux) were prospectively recruited. At entry, each patient had US and both natural- filling (NFC) and conventional-filling (CFC) cystometry. Bladder volume and wall thickness index (BVWI) was calculated, and based on US studies and the bladder pattern on US, were classified as thick (BVWI <70), normal (70-130) and thin (>130) as previously reported. The criteria for diagnosing urodynamic patterns included normal, overactive and hypocontractile, as reported previously. The correlation between the US measured variables and urodynamic findings were then evaluated. Sixty-one children (38 boys and 23 girls; mean age 4.82 years, range 1-11) were selected for further evaluation.

RESULTS

Of the 61 children, 16 had a normal BVWI, 36 a 'thick' value and nine 'thin'. When the BVWI was correlated with the urodynamic findings, 14 of 16 with a normal BVWI had a normal bladder pattern, whereas 92% of the patients with a BVWI of <70 had overactive bladder (P < 0.001). Among children with a BVWI of >130, six of nine had a hypocontractile pattern. The mean (sd) bladder capacity (on CFC) compared to that expected for age was significantly lower, at 56.7 (32.3)% in 'thick' bladders, vs children with normal and thin bladders, at 91.3 (23.8)% and 98.7 (31.8)%, respectively (P < 0.001). A high voiding detrusor pressure was significantly associated with children who had a thick bladder rather than normal or thin bladder (P < 0.001).

CONCLUSIONS

This study further confirmed that the BVWI is a sensitive tool for diagnosing bladder dysfunction in children, and it can be used as a reliable guide for the appropriate choice of further invasive urodynamic studies.

Does bladder voiding during sleep and wakefulness change the behavioural state of infants?

AIM

To evaluate whether bladder voiding in healthy infants is accompanied by body movements or any changes in heart rate (HR), respiratory frequency (RF) or electroencephalogram (EEG) frequency during sleep and during wakefulness.

METHODS

Polygraphic recordings were performed on 33 healthy infants (17 female) born at term. The infants' age at study entry was 41+/-10 d, and actual body weight was 4876+/-403 g (mean+/-SD). Bladder voiding was recorded by an adapted enuresis detector connected to the polygraphic computer unit.

RESULTS

Awakening was observed in 12 (36%) infants 77+/-9 s before bladder voiding. Twenty-one infants (64%) continued sleeping during bladder voiding. In sleeping infants, bladder voiding occurred during non-REM sleep only, and was accompanied by a cortical arousal. During wakefulness, RF was lower, and HR and EEG frequency were higher, but stayed constant during bladder voiding.

CONCLUSION

Our observations demonstrate that bladder voiding in healthy infants during sleep is accompanied by body movements and changes in HR and EEG frequency, indicating cortical arousals, whereas during wakefulness these changes cannot be observed.

Reference Ranges for Cystographic Bladder Capacity in Children—With Special Attention to Vesicoureteral Reflux

PURPOSE

Linear correlations for cystometric/cystographic bladder capacity with age universally serve as clinical yardsticks in pediatric urology and nephrology. However, these correlations do not account for growth or the range in values, as the relation of cystometric/cystographic bladder capacity with age is nonlinear. Also, vesicoureteral reflux might influence the size of cystometric/cystographic bladder capacity, since small and large bladder capacities have been reported in conjunction with reflux. We decided to use the data sets of the International Reflux Study in Children to construct full reference ranges for cystometric/cystographic bladder capacity and age, for comparison with existing reference ranges in normal children, and to study the relation between bladder capacity and refluxing volume.

MATERIALS AND METHODS

In the International Reflux Study in Children 386 patients with grade III or IV vesicoureteral reflux were followed with isotope cystography for 10 years. To follow the grade of reflux, x-ray cystography was also used at 60-month intervals. The 386 children, who were 1 month to 12 years old, were randomized into 2 groups-those undergoing surgery and those receiving medical treatment. For both groups data were available on cystometric/cystographic bladder capacity, refluxing volume, reflux grade and reflux outcome.

RESULTS

The distribution of cystometric/cystographic bladder capacity vs age is logarithmic, with a wide range between the 5th and 95th percentiles, and a clear nonlinear relation between bladder capacity and age (p < 0.001). Gender has no influence on cystometric/cystographic bladder capacity. No difference in bladder capacity exists between persistence or resolution of vesicoureteral reflux (p < 0.78), between grade III and grade IV reflux (p < 0.94), or between unilateral and bilateral reflux (p < 0.74). Thus, refluxing volume correlated only with reflux grade, not with cystometric/cystographic bladder capacity or age.

CONCLUSIONS

With or without vesicoureteral reflux values for cystometric/cystographic bladder capacity range widely in children, and correlate logarithmically with age. For clinical decisions the full reference range for age, flanked by the 5th and 95th percentiles, should be used to assess individual values for cystometric/cystographic bladder capacity, rather than linear functions.

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.

Bladder voiding in sleeping infants is consistently accompanied by a cortical arousal

The aim of the study was to find out whether bladder voiding in healthy sleeping infants was accompanied by any arousal reaction. Polygraphic recordings were performed in 21 healthy infants (11 female) born at term. The infants' age at study entry was 42 +/- 4 days and actual body weight was 4852 +/- 689 g (mean +/- SD). Bladder voiding was recorded by an adapted enuresis detector which was connected to the polygraphic computer unit. Arousals were defined as suggested by the 'International Paediatric Work Group on Arousals'. Awakenings were excluded from the study. Bladder voiding was recorded at a mean time of 68 +/- 7 min after the infant had fallen asleep and occurred during quiet sleep (QS). Electroencephalogram frequency (P < 0.01) and heart rate (P < 0.05) were higher during the 5-s period before and after bladder voiding when compared with a 30-s interval before voiding. Furthermore, bladder voiding was accompanied by body movements in all infants. Respiratory frequency did not change significantly. We could demonstrate for the first time in sleeping infants, that bladder voiding during QS was accompanied by a cortical arousal.

Clinical course of prenatally detected primary vesicoureteral reflux

The purpose of this study was to report the clinical course of medium-long-term follow-up of children with prenatally detected vesicoureteral reflux (VUR). Between 1986 and 2004, 53 (41 males) children with VUR detected by investigation of prenatal hydronephrosis were followed up for a mean time of 66 months (range: 6-200 months). Newborns were investigated by ultrasound, voiding cystourethrogram (VCUG) and DMSA scan. Follow-up clinical visits were performed at 6-month intervals. After 24 months patients were investigated by conventional VCUG or direct isotope cystogram. Survival analysis was performed in order to evaluate the resolution of the reflux. Differences between subgroups (mild vs moderate/severe reflux) were assessed by the two-sided log rank test. Thirty (58%) infants presented bilateral VUR, for a total of 83 renal units. There was a predominance of severe reflux (54%). Renal damage was detected in 33.7% of the units on first renal scan. There was a significant correlation between severe reflux and renal damage scars (RR=3.4, 95% confidence interval [CI], 1.4-8, p=0.002). Forty-seven patients were treated with continuous prophylaxis. One patient developed systolic hypertension. Urinary tract infection occurred in 12 (25%) children conservatively managed. VUR resolution was evaluated in 56 renal units. Spontaneous resolution was observed in 25 units (45%). At 48 months after diagnosis, 75% of the cases of mild reflux (I-III) and 37% of severe reflux (IV-V) had resolved (log-rank, 5.6, p=0.017). There was an improvement of nutritional parameters between admission and the end of follow-up. In conclusion, the clinical course of prenatally detected VUR followed up on a medium-long-term basis is relatively benign. Our study corroborates the results obtained in other series of infants with reflux that emphasized the heterogeneity of this disorder.

Funktionelle Störungen des unteren Harntrakts im Kindesalter

Functional disorders of the lower urinary tract as well as vesicoureteral reflux involved in the disease complex of urinary tract infection/permanent renal parenchymal damage can be considered predisposing or risk factors. Two main forms can be distinguished, i.e., unstable bladder and dysfunctional voiding, while transitional forms between the two exist. Functional disorders of the lower urinary tract obstruct spontaneous resolution of vesicoureteral reflux. They are found in about 50% of cases in all children with urinary tract infection and are associated with an increased risk of developing renal parenchymal scars. They are observed during the newborn period up to school age. In the first few months of life, particularly boys with bilateral high-grade reflux and congenital renal parenchymal damage are affected. At later ages girls are also affected, but in this age group bladder instability predominates. Incontinence as the leading clinical symptom appears in approximately 70% of all cases and is closely correlated with chronic constipation. Imaging procedures in addition to urodynamic methods are of decisive importance for diagnosis and treatment, but noninvasive approaches such as sonography should be given preference.

[Urodynamic investigations in children]

Performing urodynamic investigations in children presents some difficulty due to the lack of any normogram, and due to the results that vary with age. Such investigation is therefore carried out only when clinical examination and radiological assessment fail to explain a voiding dysfunction. The procedure should be performed in a urodynamic unit that has paediatric expertise. A specific paediatric procedure is to be respected when performing uroflowmetry and cystometry in children. Assessing the urethral pressure profile is very difficult since moving a catheter along the urethra causes a reflex activity of the pelvic floor muscles. Main indications are: neuropathic bladders, voiding dysfunctions, urinary infections, anorectal malformations and pelvic tumours. As in adults, urodynamic investigations are useful when selecting a therapeutic strategy.

Findings in cystourethrography that suggest lower urinary tract dysfunction in children with vesicoureteral reflux

PURPOSE

Children with lower urinary tract dysfunction and vesicoureteral reflux, at cystography assessment, frequently present alterations in the lower urinary tract anatomy such as dilated posterior urethra, irregularity of the bladder wall and diverticula. However, the significance of these findings is unknown. The objective of this study is to evaluate the incidence of these findings, their time of disappearance and their correlation with the severity of the reflux.

MATERIALS AND METHODS

193 children with vesicoureteral reflux, considered simple, in the age group above 5 years at the moment of diagnosis, were analyzed. The recommendation for follow-up of these patients was one voiding cystoureterography (VCUG) each year. Only patients with a minimum of 2 VCUGs performed in a period of at least 6 months were considered. The VCUGs were classified as positive and negative in relation to findings that were characteristic of lower urinary tract dysfunction (LUTD).

RESULTS

From the 193 children analyzed, 50 (26%) presented positive VCUG and 143 negative VCUG. From the patients without symptoms of lower urinary tract dysfunction (n = 135), 12 (9%) presented positive VCUG and 123 (91%) a negative VCUG. From the patients with negative VCUG, 68 (48%) presented unilateral reflux and 75 (52%) presented bilateral reflux. From those with positive VCUG, 26 (52%) had unilateral reflux and 24 bilateral reflux (48%). This difference was not statistically significant. A higher incidence of grade II reflux was more evident in patients with negative VCUG and degree III in patients with positive VCUG (p < 0.05).

CONCLUSIONS

Our study demonstrated that 64% of the patients with LUTD and reflux presented findings in the VCUG that suggest dysfunction.

Voiding dysfunction in children

The practicing urologist commonly sees children with lower-urinary tract dysfunction who wet or have recurrent urinary tract infections. This article identifies the proposed etiologies of such behavior in children in whom there are no anatomic or neuropathic causes, outlines the approach to evaluating affected children, and describes a stepwise,interdisciplinary approach to treatment.

A multivariate analysis of dysfunctional elimination syndrome, and its relationships with gender, urinary tract infection and vesicoureteral reflux in children

PURPOSE

We explored and quantified the relationships between dysfunctional elimination syndrome (DES), and gender, urinary tract infection (UTI) and vesicoureteral reflux (VUR) in children.

MATERIALS AND METHODS

Data on 2,759 pediatric patients treated at a referral practice who underwent renal sonography and voiding cystourethrography were summarized. The patients were children with VUR or normal genitourinary anatomy who presented with UTI or dysfunctional voiding and children screened for genitourinary problems such as hematuria, sibling reflux or bedwetting. A multivariate logistic regression approach was used to model and quantify the associations between DES and other pediatric urology factors.

RESULTS

Of the girls 36.0% with unilateral VUR had DES, while 36.1% with bilateral VUR had DES. The corresponding rates for boys were 20.5% and 21.2%. The higher rate of DES in girls was independent of UTI and VUR status. While UTI was not associated with DES in boys or girls without VUR, in patients with VUR and UTI the risk of DES almost doubled (OR 1.97). Reflux alone without UTI was negatively associated with DES in boys (OR 0.50, 95% CI 0.34, 0.73) and girls (OR 0.26, 95% CI 0.19, 0.36).

CONCLUSIONS

Girls had a significantly higher rate of DES than boys in all UTI and VUR subgroups in the current data. UTI significantly impacts the DES occurrence in patients with VUR. No statistically significant difference was detected in the DES rate between the unilateral and bilateral VUR groups, and the reflux group as a whole did not seem to have a higher rate of DES in boys or girls.

Videourodynamic Findings in Young Infants With Severe Primary Reflux

PURPOSE

We investigated bladder function on videourodynamic studies in infants with severe primary vesicoureteral reflux (VUR) and analyzed the relationship between VUR and intravesical detrusor pressure during the micturition cycle.

MATERIALS AND METHODS

From 1999 to 2001, 3 female and 9 male infants with a median age of 9 months with VUR underwent conventional filling videourodynamics at our institution. Four cases were diagnosed by prenatal detection and 8 were diagnosed after symptomatic urinary tract infections. Reflux was bilateral in 5 cases and unilateral in 7 (grades III to V in 7, 7 and 3, respectively). Controls included 10 age matched infants (median age 4 months) studied with the same urodynamic methodology.

RESULTS

Median cystometric bladder capacity expected for age +/- SD was 50% +/- 58% (range 20% to 240%). Bladder capacity was low (less than 80%) in 10 patients. Detrusor overactivity during filling was found in only 1 patient. In all except 1 case voiding alternated with peaks of high detrusor pressure (median 87 +/- 25 cm water), associated with intermittent external sphincter contractions with normal coordinated micturition (median 36 +/- 7 cm water). Cystometric residual urine (30% or greater) was noted in 3 cases. In 5 patients VUR occurred with an increase in bladder pressure, while in 7 it occurred during stable filling. No significant cystometric differences were found between patients with reflux and controls.

CONCLUSIONS

Most infants with VUR had decreased cystometric bladder capacity and normal detrusor activity during filling. High voiding pressure with concomitant sphincteric overactivity coexisted with normal micturition. This voiding pattern might represent a developmental stage of normal urine control and it may have a role in the etiology of reflux in some infants.

Risk of renal scarring in vesicoureteral reflux detected either antenatally or during the neonatal period

OBJECTIVES

To evaluate both the demographic features and the renal outcome of fetal vesicoureteral reflux (VUR), two well-defined populations were analyzed: those with hydronephrosis detected by obstetric ultrasonography, and neonates diagnosed after developing their first urinary tract infection within the first 4 postnatal weeks.

METHODS

Twenty-one neonates with antenatally detected VUR were compared with 30 patients with neonatally detected symptomatic disease. The mode of presentation, fate of reflux, and renal outcome were analyzed.

RESULTS

Significantly more bilateral dilating VUR was found in postnatally versus antenatally diagnosed patients (53% versus 29%; P = 0.05). Fourteen percent presented with congenital renal dysplasia. No difference was found in the incidence of congenital dysplasia between the two groups. Focal renal scars developed during follow-up in 19% of renal units. New scars were observed in dilating VUR only, especially in grades 4 and 5 (P <0.05), and these were exclusively in the postnatal patient group (P <0.005).

CONCLUSIONS

Several demographic features of fetal VUR differ, depending on whether detected antenatally or postnatally. The incidence of bilateral dilating VUR was greater in postnatally detected cases, suggesting a more severe manifestation of the disease. Renal injury occurred in an appreciable number of renal units. The damage may be of congenital origin or may be acquired secondary to urinary tract infection. The risk of acquired renal scarring is particularly significant if dilating VUR is not detected until neonatally after the first urinary tract infection.

Anomalías renales congénitas en neonatos con reflujo vesicoureteral fetal. Detección con gammagrafía renal- 99m Tc-DMSA

BACKGROUND

"Fetal" vesicoureteral reflux (VUR) is characterized by predominance among males, high grade reflux and renal parenchymal abnormalities, indicating an association between sterile VUR and kidney lesions.

OBJECTIVES

To determine, using technetium99m-dimercaptosuccinic acid (99mTc-DMSA) renal scan, the incidence of congenital renal abnormalities in infants with sterile VUR detected during the postnatal evaluation of prenatal hydronephrosis or sibling reflux screening and to speculate on the mechanisms of these lesions.

METHODS

We retrospectively reviewed the DMSA renal scans of infants with VUR without a history of urinary tract infection (UTI). DMSA differential uptake less than or equal to 40% or cortical defects were considered as renal abnormalities. The findings were correlated with those of postnatal renal ultrasonography.

RESULTS

Eighteen patients (15 boys and 3 girls) were included with VUR grade V, IV, III and II in 5, 10, 6 and 6, respectively, of the 36 renal units. DMSA revealed parenchymal abnormalities in 50% (9/18) of the patients and in 33% (9/27) of the renal units with VUR; most of the patients were boys (7 boys, 2 girls) with VUR grade V or IV (6/9; 66%). Postnatal ultrasonography showed low sensitivity (22%) to renal injury.

CONCLUSIONS

In infants with sterile VUR, especially boys with high grade VUR, kidney abnormalities can already be present at birth suggesting a pathophysiology of renal injury independent of UTI. Moreover, renal parenchymal defects detected by DMSA renal scan are frequently not identified by postnatal renal ultrasound. Therefore, we recommend DMSA scanning in the initial evaluation of infants with VUR.

The outcome of voiding dysfunction managed with clean intermittent catheterization in neurologically and anatomically normal children

OBJECTIVE

To describe the tolerability and efficacy of clean intermittent catheterization (CIC) in the management of dysfunctional voiding in patients who are neurologically and anatomically normal.

PATIENTS AND METHODS

The medical records were reviewed in 23 patients (16 girls, mean age 9 years, range 6-14.5, and seven males, mean age 8 years, range 5-20.5) with urinary incontinence and/or urinary tract infection (UTI) who were offered CIC because they had a large postvoid residual urine volume (PVR). All had extensive instruction before starting CIC. All patients underwent urodynamic studies, and urinary and fecal elimination habits were recorded. Detrusor hyperactivity, when present, was treated with anticholinergic medication. The follow-up evaluation included tolerance of CIC, continence status and the incidence of UTI. Behavioural modification or biofeedback training was not used in any patient.

RESULTS

Of the 23 patients, 13 presented with both UTI and urinary incontinence, five with incontinence only, four with UTI only, one with frequency and no incontinence, and one with haematuria. Associated symptoms included frequency/urgency, constipation or soiling, and straining to void or incomplete emptying (in nine each), and infrequent voiding in six. CIC was performed within 2 days by 15 patients, while four others required up to 2 weeks to master CIC. However, three of the four patients (all older girls) who needed 2 weeks to learn the technique did not tolerate CIC and discontinued it within 3 weeks. Four other adolescents (three girls and one boy) refused to learn CIC. Of the 16 patients remaining on CIC only three had cystitis; no patient had a febrile UTI. Once successfully instituted, all patients became continent while on CIC. Six boys (mean follow-up 4 months) had a marked decrease in their PVR. CIC was discontinued in three girls who voided normally to emptiness within 6 months of starting CIC; they remained dry and infection-free 16 months (two) and 6 years later.

CONCLUSION

CIC is a viable therapeutic option for the treatment of dysfunctional voiding, associated with a large PVR, in the absence of any neurological abnormality. CIC is well tolerated in the sensate patient and provides a means for expeditiously achieving continence and improving bladder emptying cost-effectively.

Bladder function in healthy neonates and its development during infancy

PURPOSE

Bladder function in healthy neonates and its development during infancy are described.

MATERIALS AND METHODS

Results of free voiding studies of healthy neonates and infants using 4-hour voiding observation and urodynamics studies were reviewed.

RESULTS

According to these studies, voiding in the healthy neonate is characterized by small, frequent voids of varying volume in the individual case and interrupted voiding in 30% of the cases. Interrupted voiding is clearly an immature phenomenon since it is seen in 60% of preterm neonates and disappears completely before the age of toilet training. These voidings are considered to be due to a dyscoordination between the sphincter and detrusor, which has also been observed on urodynamic studies and which probably also explains incomplete emptying seen in this age group. Emptying remains incomplete to the age of toilet training when residual urine is median 0 ml. during 4 hours of observation. Voiding rarely occurs during quiet sleep even in the neonatal period, when signs of arousal are often noted before voiding. However, voiding during sleep in 60% occurs of preterm infants, indicating that it may be due to maturation of the central nervous system. Bladder instability is rarely seen in healthy neonates and infants according to urodynamic studies but hyperactivity is suggested in the neonatal bladder with premature voiding contractions after only a few milliliters of filling and with leakage of urine. This latter phenomenon probably explains the low cystometric bladder capacity in this age group. High voiding pressure levels also accompany this low bladder capacity.

CONCLUSIONS

Thus, it can be suggested that the neonatal bladder is regulated by neuronal pathways with connections to the cerebral cortex in the neonatal period, which is contrary to the earlier concept of voiding as an automatic event in response to a constant volume in the bladder. This theory does not mean that voiding is conscious or voluntary in this age group, but only that the voiding reflex disturbs the neonate. New characteristics include the concept of physiological dyscoordination, such as hyperactivity of the detrusor seen as low bladder capacity, and high voiding pressures in the neonatal period.

The relationship between early renal status, and the resolution of vesico-ureteric reflux and bladder function at 16 months

OBJECTIVE

To examine, in infants presenting with vesico-ureteric reflux (VUR), the relationship between the presence of initial renal abnormalities with the outcome of VUR and bladder function at 16 months of age.

PATIENTS AND METHODS

The study group comprised 40 infants (32 boys) presenting consecutively (29 after prenatal detection) with VUR grade III or greater (bilateral in 29) on the initial micturating cystogram (median age 8 weeks). The initial presence of abnormal kidneys was determined from isotopic renography and/or ultrasonography. These data were correlated with the outcome of VUR, from direct isotope cystography, and bladder function assessed by natural filling urodynamics, examined at age 16 months (mean 16.4 months, SD 2.1).

RESULTS

Three groups were identified. Group 1 (eight boys and six girls) had normal kidneys bilaterally; initially grade III VUR was common. At 16 months bladder function was normal in 10 children and none had VUR (complete resolution). Group 2 (14 boys and two girls) had unilateral renal abnormalities; initially VUR was predominantly grade IV or grade V. At 16 months bladder function was normal in eight children and VUR resolved in eight, five of these with normal bladder function. Group 3 (10 boys) had bilateral renal abnormalities. Initially grade V VUR predominated; at 16 months the bladder function was normal in only one, and in the rest the emptying dynamics were abnormal. All 10 boys had persisting VUR (no resolution).

CONCLUSIONS

In infants with moderate or severe VUR, resolution at 16 months old is associated with normal kidneys in a similar proportion of boys and girls. Resolution also correlates well with normal bladder function. Presentation in infancy with bilateral abnormal kidneys, associated with severe VUR in boys, is a poor prognostic sign for the early outcome of VUR and for bladder function.

Bladder functional outcome after delayed vesicostomy closure and antireflux surgery in young infants with 'primary' vesico-ureteric reflux

OBJECTIVE

To evaluate bladder function by conventional urodynamic investigations in young infants with primary vesico-ureteric reflux (VUR) who had undergone an initial temporary cutaneous vesicostomy followed by later antireflux surgery and vesicostomy closure.

PATIENTS AND METHODS

From 1983 to 1990, nine boys (10-360 days old) with primary VUR were treated with an initial vesicostomy, followed by delayed closure of the vesicostomy and the simultaneous surgical correction of reflux. Severe VUR was detected bilaterally in seven and unilaterally in two infants at the time of the initial diagnosis. The mean (SD, range) age at vesicostomy was 12.4 (8, 3-23) months and the duration of bladder defunctionalization 38.7 (25.5, 18-90) months. All patients were assessed urodynamically after closing the vesicostomy, using rapid-fill cystometry with normal saline solution at room temperature. The mean (range) age at the time of urodynamic testing was 7.3 (5-15) years; the mean (SD, range) follow-up was 10.1 (4.1, 5-17) years.

RESULTS

Six boys with bilateral VUR underwent successful ureteroneocystostomy; nephroureterectomy was required in one patient. In two patients the VUR resolved with time. After re-functionalization, the mean (SD, range) maximum cystometric capacity, expressed as a percentage of the mean bladder capacity for age, was 1.4 (0.5, 0.6-2.2)%. In three patients the bladder capacity was higher (> or = 40%) than expected for age, while one had diminished (< 70%) bladder capacity. The mean (range) end-filling detrusor pressure was 14.5 (5-42) cmH2O and the mean (SD, range) compliance 24 (13.9, 4-44) mL/cmH2O. Two patients had a compliance of < 10 mL/cmH2O, one of whom had associated unstable detrusor contractions of 90 cmH2O. The mean (SD, range) detrusor voiding pressure at peak flow was 47.3 (16.8, 5-76) cmH2O. One patient had a residual urine volume of 8% of bladder capacity. At the follow-up, only one patient (aged 5 years) with detrusor instability had urinary incontinence.

CONCLUSION

This study shows that the bladder of young infants with primary VUR treated with temporary vesicostomy regained normal function after re-functionalization of the lower urinary tract.

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.

The relationship between dysfunctional voiding and congenital vesicoureteral reflux

Voiding dysfunction may play an etiological role in congenital vesicoureteral reflux in otherwise normal children. There is increasing evidence to suggest that in some infants and older children, vesicoureteral reflux is associated with congenital structural deficiency of the trigonal ureterovesical junction valve mechanism as well as aberrant lower urinary tract function. In the youngest infants this abnormal function can be present at birth, whereas in older children it may be acquired and learned during the toilet training years, if it is not already present. Voiding dysfunction may spontaneously improve or require additional therapy. Increased rates of breakthrough infection, renal scarring and surgical failure have been associated with undiagnosed and untreated lower urinary tract dysfunction, emphasizing the importance of its recognition. Controversy remains regarding the role of invasive urodynamics and anticholinergic medication, and further large-scale prospective studies are necessary before either modality becomes routine when assessing and treating these children.

Relationship among pediatric voiding dysfunction and vesicoureteral reflux and renal scars

OBJECTIVES

To analyze the relationship among non-neurogenic voiding dysfunction, vesicoureteral reflux (VUR), and renal scarring, taking into consideration whether the reflux was unilateral or bilateral. VUR is a common problem in the pediatric age group. Although unilateral reflux is usually due to primary insufficiency of the vesicoureteral junction, bilateral reflux can also be the result of underlying voiding dysfunction.

METHODS

Between 1993 and 1998, 80 children, 52 girls and 28 boys, median age 5.7 years (range 3.8 to 14), were evaluated because of VUR. Eighteen patients who presented with associated anomalies and obvious neuropathic bladder dysfunction were excluded from the study. Complete urologic, neurologic, and urodynamic investigations were performed in all patients.

RESULTS

Of 62 patients, 25 (40.3%) had unilateral and 37 (59.6%) had bilateral reflux. Voiding dysfunction was found in 7 patients (28%) with unilateral reflux and in 27 patients (72.9%) with bilateral reflux (P <0.01 ). Two (25%) of the 8 patients with unilateral reflux and renal scarring had voiding dysfunction but no demonstrable urinary tract infection, and 10 (55.5%) of the 18 patients with bilateral reflux and renal scarring had voiding dysfunction and no demonstrable urinary tract infection (P <0.01).

CONCLUSIONS

If VUR is bilateral, the prevalence of existing underlying voiding dysfunction seems to be higher. The first step in management should be a detailed evaluation of bladder function to choose an appropriate treatment modality and to prevent renal deterioration.

Urodynamic pattern in asymptomatic infants: siblings of children with vesicoureteral reflux

PURPOSE

We studied the urodynamic pattern in asymptomatic infants who are siblings of children with vesicoureteral reflux.

MATERIALS AND METHODS

Cystometry and perineal electromyography were performed with voiding cystourethrography in 16 male and 21 female infant siblings screened for reflux at age 0.2 to 7.3 months (median 1.1).

RESULTS

Vesicoureteral reflux was present in 25% of the male and 10% of the female infants. In those without vesicoureteral reflux unstable bladder contractions were noted in 8% of the male and 16% of the female subjects. In these infants median maximum voiding detrusor pressure was 127 (range 84 to 211) and 72 cm. water (range 42 to 240), respectively, and median bladder capacity was 20 ml. (range 10 to 49 and 10 to 120, respectively). Maximum voiding detrusor pressure was significantly higher in male than in female infants (p <0.01). Perineal electromyography was interpretable in 13 of the 16 male and 16 of the 21 female infants overall. All but 1 female subject had increased activity during voiding, which was also present intermittently in all subjects.

CONCLUSIONS

Our study of asymptomatic siblings of children with vesicoureteral reflux has provided results that may be used as reference data for normal urodynamics in early infancy. Instability was rare. Bladder capacity was lower than expected with a predicted capacity at birth of approximately 20 ml. Maximum voiding pressure was high, especially in male subjects. The urodynamic voiding pattern suggests physiological dyscoordination, probably due to immature detrusor-sphincter function.

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.

Experimental fetal vesicoureteral reflux induces renal tubular and glomerular damage, and is associated with persistent bladder instability

PURPOSE

We assessed renal function and urodynamic status in animals with experimental congenital vesicoureteral reflux.

MATERIALS AND METHODS

Vesicoureteral reflux was surgically induced in male sheep fetuses at 95 days of gestation. After birth the animals were maintained on antibiotic prophylaxis. At ages 1 week and 6 months reflux was assessed by fluoroscopic voiding cystography. Cystometrography was performed with the animals awake. Serum creatinine, inulin clearance and the excretion of urinary N-acetyl-beta-D-glucosaminidase were measured at ages 1 week, 1 month and 6 months by surveillance urine cultures. Urinary concentrating capacity was assessed by desmopressin testing at ages 1 and 6 months.

RESULTS

Nine animals (18 renal units) were born after the induction of reflux. There was no reflux in 2 renal units, while reflux was mild in 2, moderate in 5 and severe in 9. In the 6 animals available for followup at age 6 months only severe reflux persisted. Reflux resolution was associated with normalization of bladder urodynamics. Surveillance urine cultures were negative until age 6 months, when infection developed in 3 of the 6 lambs. In all animals serum creatinine was normal during followup. Glomerular filtration rate in the lambs with reflux was no different from normal at age 1 week but it was significantly less than normal independent of infection at age 6 months (2.7 versus 3.9 ml./kg. per minute, p = 0.002). As an indicator of renal tubular injury the ratio of N-acetyl-beta-D-glucosaminidase-to-creatinine remained significantly higher in animals with reflux than in normal animals from ages 1 week to 6 months (51.0 versus 10.2 IU/mg., p = 0.03). Maximal concentrating ability after desmopressin testing was already less than normal by age 1 month with a maximal increase of 98 versus 435 mOsm./l. in lambs with reflux versus normal lambs (p <0.0001). It was further impaired by age 6 months. Urodynamic evaluation of the animals with reflux revealed decreased bladder compliance at age 1 week with normal voiding pressure. In addition, in those with reflux there was a more pronounced immature voiding pattern with multiple phasic contractions due to sphincteric activity as well as a post-void bladder contraction.

CONCLUSIONS

Our model of fetal vesicoureteral reflux induces alterations in renal function that are consistent with clinical observations and marked by altered tubular function but a relatively mild decrease in glomerular filtration. Bladder dynamics are altered, consistent with observations in human neonates with high grade reflux and bladder instability. Whether this represents cause or effect remains unclear. Our model permits focused study of the interaction of these factors in neonatal reflux and may allow the application of more specific therapies, particularly those directed toward mechanisms of renal and bladder dysfunction.

Experimental fetal vesicoureteral reflux induces renal tubular and glomerular damage, and is associated with persistent bladder instability

PURPOSE

We assessed renal function and urodynamic status in animals with experimental congenital vesicoureteral reflux.

MATERIALS AND METHODS

Vesicoureteral reflux was surgically induced in male sheep fetuses at 95 days of gestation. After birth the animals were maintained on antibiotic prophylaxis. At ages 1 week and 6 months reflux was assessed by fluoroscopic voiding cystography. Cystometrography was performed with the animals awake. Serum creatinine, inulin clearance and the excretion of urinary N-acetyl-beta-D-glucosaminidase were measured at ages 1 week, 1 month and 6 months by surveillance urine cultures. Urinary concentrating capacity was assessed by desmopressin testing at ages 1 and 6 months.

RESULTS

Nine animals (18 renal units) were born after the induction of reflux. There was no reflux in 2 renal units, while reflux was mild in 2, moderate in 5 and severe in 9. In the 6 animals available for followup at age 6 months only severe reflux persisted. Reflux resolution was associated with normalization of bladder urodynamics. Surveillance urine cultures were negative until age 6 months, when infection developed in 3 of the 6 lambs. In all animals serum creatinine was normal during followup. Glomerular filtration rate in the lambs with reflux was no different from normal at age 1 week but it was significantly less than normal independent of infection at age 6 months (2.7 versus 3.9 ml./kg. per minute, p = 0.002). As an indicator of renal tubular injury the ratio of N-acetyl-beta-D-glucosaminidase-to-creatinine remained significantly higher in animals with reflux than in normal animals from ages 1 week to 6 months (51.0 versus 10.2 IU/mg., p = 0.03). Maximal concentrating ability after desmopressin testing was already less than normal by age 1 month with a maximal increase of 98 versus 435 mOsm./l. in lambs with reflux versus normal lambs (p <0.0001). It was further impaired by age 6 months. Urodynamic evaluation of the animals with reflux revealed decreased bladder compliance at age 1 week with normal voiding pressure. In addition, in those with reflux there was a more pronounced immature voiding pattern with multiple phasic contractions due to sphincteric activity as well as a post-void bladder contraction.

CONCLUSIONS

Our model of fetal vesicoureteral reflux induces alterations in renal function that are consistent with clinical observations and marked by altered tubular function but a relatively mild decrease in glomerular filtration. Bladder dynamics are altered, consistent with observations in human neonates with high grade reflux and bladder instability. Whether this represents cause or effect remains unclear. Our model permits focused study of the interaction of these factors in neonatal reflux and may allow the application of more specific therapies, particularly those directed toward mechanisms of renal and bladder dysfunction.