The role of videourodynamic studies in diagnosis and treatment of vesicoureteral reflux

Vesicoureteral reflux and urodynamic dysfunction

INTRODUCTION

The concept of vesicoureteral reflux (VUR) as a consequence of congenital anomaly of vesicoureteral junction has undergone changes owing to the finding that such children may have lower urinary tract dysfunction, which produces high intravesical pressure and consequently a predisposition for VUR.

PATIENTS AND METHODS

The urodynamics was investigated by pressure-flow-EMG study in 132 children with VUR and 162 refluxing units.

RESULTS

Only 33 (25.0%) patients had normal urodynamic finding. The most frequent pathological finding was overactive bladder (OAB), found in 59 (44.7%) children, followed by dysfunctional voiding (DV) in 25 (18.9%) children. Children with VUR grades I and II had a higher percentage of pathological urodynamic findings than children with VUR grades III and IV. OAB was more frequent in children under 5 years of age with unilateral and lower grade VUR. It was found equally in children with and without uroinfections. DV was more frequent in children older than 5 years, with bilateral VUR, higher grade VUR and uroinfections.

CONCLUSIONS

Children with VUR have a high incidence of urodynamic disorders. The results of the study indicate the possible role of urodynamic dysfunction in the pathogenesis of VUR, especially mild one.

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.

Radionuclide voiding patterns in children with vesicoureteral reflux

The purpose of this study was to evaluate bladder function in children with vesicoureteral reflux (VUR) by means of indirect radionuclide cystography (IRNC), and to investigate whether IRNC can identify those children with voiding dysfunction. The study enrolled 74 neurologically intact children, 14 boys and 60 girls aged 2-14 years, with VUR documented using contrast micturating cystourethrography as the initial method. In all patients, IRNC was performed using technetium-99m diethylene triamine penta-acetate (DTPA). Based on the urodynamic findings, three groups were distinguished: a group with VUR and normal urodynamic findings ( n=27), a group with VUR and detrusor hyper-reflexia ( n=43) and a group with VUR and detrusor-sphincter dyssynergia ( n=4). A control group comprised 64 healthy children, aged 2-13 years, without any symptoms of lower urinary tract dysfunction. The dynamics of bladder emptying were studied in the posterior view after intravenous injection of 37 MBq/10 kg b.w. DTPA, with acquisition of 90 2-s frames during voiding. The parameters evaluated were: voided urine volume (VV), bladder capacity, functional bladder capacity (FBC), residual urine, voiding time, average flow rate, peak flow rate (PFR) and ejection fraction (EF). With regard to the final urodynamic diagnosis, FBC, PFR and EF were found to be significant IRNC predictor variables using the logistic regression method. If abnormality on at least two of the three significant predictor variables was taken as the criterion of voiding dysfunction, the overall sensitivity, specificity and accuracy of IRNC in the detection of voiding dysfunction were 81%, 78% and 80%, respectively. Three radionuclide voiding patterns were detected in children with VUR: (1) a normal voiding pattern characterised by normal FBC with near-normal PFR and EF values, (2) a markedly reduced FBC with significantly reduced VV, PFR and EF values (in children with bladder instability), and (3) a higher bladder volume with a near-normal value for PFR and a slightly reduced or near-normal EF (in children with detrusor-sphincter dyssynergia). This study confirmed the association between lower urinary tract dysfunction and congenital VUR. IRNC was found to be a simple, non-invasive method which allows reliable differentiation of voiding patterns in patients with VUR. IRNC can be used as a first-line method for screening in children with VUR to identify those with abnormal voiding patterns.

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.

Vesicoureteral reflux and videourodynamic studies: results of a prospective study

OBJECTIVES

To study the influence of bladder instability on the conservative management and surgical treatment of children with vesicoureteral reflux (VUR), 102 children were included in a prospective study.

METHODS

During a 5-year period all children suspected to have VUR underwent a videourodynamic study to determine VUR grade and bladder function. This resulted in a group of 36 boys and 66 girls who were followed up for well over 5 years.

RESULTS

Bladder instability was found in 41 of 102 children (40%). The 102 children were either treated conservatively or surgically. Of the 77 children who were treated conservatively, bladder instability was found in 35 patients. In the conservatively treated group with bladder instability, reflux resolved in 57%; whereas in those with normal bladder function, reflux resolved in 67%. Of the 25 patients who were treated surgically, the operation was successful in 91%. Breakthrough infections occurred in 22 girls and 3 boys, including 14 of 41 patients with bladder instability (34%) and 11 of 61 patients with normal bladder function (18%).

CONCLUSIONS

Bladder instability is a frequent finding and an important factor in the treatment of children with VUR. To determine if a patient has VUR and bladder instability a videourodynamic study has proved to be an easy and efficient diagnostic tool. When bladder instability is treated with anticholinergic medication, almost the same results can be expected from conservative treatment as from surgical treatment compared to children with a normal bladder function. Breakthrough urinary tract infections occur more often in girls and tend to occur more often in children with bladder instability.

Vesicoureteric reflux and videourodynamic studies: results of a prospective study after three years of follow-up

OBJECTIVE

To study prospectively the influence of videourodynamic studies on the management of children with vesicoureteric reflux.

METHODS

One hundred one children with reflux were investigated routinely with videourodynamic studies, as well as renal scans, ultrasound studies, and/or intravenous urograms. The studies were repeated at one, three, and five years. If bladder instability was demonstrated, the primary treatment consisted of anticholinergic drugs and antibiotics, regardless of the grade of reflux. In reflux Grades IV and V with instability and renal scars, surgery was performed. In case of a stable bladder, reflux Grades I-III received antibacterial treatment, while surgical correction was used for reflux Grades IV and V.

RESULTS

The results of three years of follow-up of 101 children are reported. Bladder instability was found in 39 children. Thirty of them with reflux Grades I-IV and instability could be managed with anticholinergic and antibacterial drugs, while 9 needed surgical correction.

CONCLUSIONS

A voiding cystourethrogram is only sufficient for the detection of reflux but for correct management of these children a (video)urodynamic study is mandatory. After treatment of frequently found bladder dysfunction, the reflux will disappear in the majority of cases.

Treatment of vesicoureteric reflux. Results of a prospective study

Between 1982 and 1986, 96 children with non-obstructive vesicoureteric reflux were included in a prospective study. Three patients withdrew from the study and results are therefore presented on 93 children with 135 refluxing ureters who were followed up for at least 5 years. Initially, all children with reflux grade III or less received antibiotic treatment only. Those with reflux grade IV were randomised to antibiotic treatment alone versus surgery plus antibiotic treatment; the primary treatment of reflux grade V was reimplantation. In 85 ureters treated by antibiotics only, reflux disappeared in 64 cases and was reduced in 12. In 50 ureters treated by reimplantation, reflux was cured in 46 cases and no severe ureteric obstruction was seen. Conservative management of reflux grade IV was less successful than surgery. The results of conservative, non-surgical treatment of reflux grades I-III were satisfactory, but for grades IV and V surgery should be the treatment of choice if detrusor instability has been excluded.

The detection and characterization of vesicoureteral reflux in the child

Voiding cystourethrography or radionuclide cystography should be performed in the child in whom it is important to know whether reflux is present. Voiding cystourethrography is more accurate in characterizing and grading reflux, and monitoring is intermittent. Conversely, radionuclide cystography uses a lower radiation dose and its continuous monitoring leads to fewer false negative results but its ability to characterize reflux is poor. The performance of voiding cystourethrography or radionuclide cystography to detect reflux is an art as well as a science. These tests are done best by those who are experienced and interested in imaging the urinary tract of the child. At our hospital we perform voiding cystourethrography in all young children with urinary tract infection to detect and precisely characterize reflux to enable intelligent planning of management. In older patients, when it is less likely that reflux is present but it is still desirable to ensure that reflux is not occurring, radionuclide cystography is performed. If reflux is present, then a decision is made on an individual basis as to whether additional characterization by voiding cystourethrography is needed. Radionuclide cystography is also used for family screening, for periodic followup of reflux being managed nonoperatively and to ensure that reflux has been eliminated after antireflux surgery.