A plea for standardized grading of vesicoureteral reflux

Ultrasound-based predictive indicators for treatment outcomes in pediatric vesicoureteral reflux

PURPOSE

To evaluate the effectiveness of preoperative ultrasound (US) measurements in predicting pediatric vesicoureteral reflux (VUR) treatment outcomes.

METHODS

This prospective study enrolled 35 patients (53 renal units) aged 1-16 years who underwent subureteric injection therapy for primary VUR between July 2020 and June 2022. Preoperative ultrasound examinations measured the bladder wall thickness at the ureteral orifice, ureteral submucosal tunnel length, distal ureteral diameter, patient demographics, VUR grade, presenting complaints, bladder-bowel dysfunction, and renal scarring, and the impact of these variables on treatment success was analyzed.

RESULTS

Among the patients, 91.4% were female, with a mean age of 6.83 ± 3.84 years. A comparison between the treatment success and failure groups revealed no significant differences in the age, sex, VUR grade, laterality, bilaterality, presenting complaints, bladder-bowel dysfunction, bladder wall thickness, or distal ureteral diameter (p > 0.05). However, renal scarring occurred in 16 (38.1%) patients in the treatment success group and 10 (90.9%) in the treatment failure group (p = 0.002). The treatment failure group had shorter detrusor-to-ureteral orifice distances and smaller detrusor-ureteral orifice distance-to-distal ureteral diameter (D/U) ratios than that of the success group (p = 0.004 and p = 0.006, respectively). Patients with a detrusor-to-ureteral orifice distance < 7.4 mm had an 81.82% likelihood of treatment failure.

CONCLUSION

Ultrasound measurements of the detrusor-to-ureteral orifice distance and D/U ratio proved reliable in predicting the success of endoscopic subureteric injection therapy for VUR.

The concerns of mechanical upper urinary tract obstruction in neurogenic lower urinary tract dysfunction: Beyond augmentation cystoplasty

Purpose

To evaluate the efficacy of augmentation uretero-enterocystoplasty (AUEC), a modified surgical procedure that focuses the mobilization of the ureter and the necessity of ureteroplasty in a series of neurogenic lower urinary tract dysfunction (NLUTD) patients with mechanical upper urinary tract obstruction (mUUTO).

Methods

We retrospectively reviewed the medical records of NLUTD patients who underwent an AUEC from 2005 to 2022. mUUTO was diagnosed by preoperative bladder drainage, magnetic resonance urography (MRU), and isotope renography. Upper urinary tract dilatation (UUTD) was evaluated using MRU with the Liao MRU-UUTD system.

Results

A total of 58 patients and 103 ureters were analyzed. Improvement in maximum bladder capacity (from 79.0 [41.3-163.8] to 500.0 [450.0-597.5] ml, P < 0.001), maximum detrusor pressure (from 32.0 [13.0-50.8] to 5.5 [4.0-10.0] cmH₂O, P < 0.001) and bladder compliance (from 6.5 [3.0-11.9] to 50.1 [37.5-65.0] ml/cmH₂O, P < 0.001), and stabilization of serum creatine (93.4 [73.0-142.7] to 94.9 [72.2-148.7] μmol/L, P = 0.886) were observed. The proportion of high-grade UUTD was significantly reduced after the surgery (92.3% vs. 13.5%, 92.1% to 9.8%, P < 0.001), and the typical imaging signs of preoperative obstruction disappeared.

Conclusion

Beyond traditional augmentation cystoplasty, more attention should be paid to the relief of mUUTO and mobilization of the ureter in NLUTD patients.

Is there a relationship between renal scarring and neutrophil-to-lymphocyte ratio in patients with vesicoureteral reflux?

OBJECTIVES

Vesicoureteral reflux (VUR) exacerbates the risk of renal scarring by establishing a ground for pyelonephritis. It is known that the inflammatory process is more influential than the direct damage caused by bacterial infection in the development of renal scars after pyelonephritis. Therefore, the present study aims to investigate the relationship between renal scarring and systemic inflammatory markers in patients with VUR.

MATERIAL AND METHODS

Hundred and ninety-two patients (116 females, 76 males) diagnosed with VUR were divided into two groups based on the presence or absence of renal scarring and into three groups according to the grade of VUR (low, moderate and high). Neutrophil count, lymphocyte count, mean platelet volume (MPV) and neutrophil-to-lymphocyte ratio (NLR) were compared among the groups.

RESULTS

Of the 192 patients, 102 had renal scarring. The age and gender distribution did not differ significantly between the groups with and without renal scarring (p > 0.05). However, the grade of reflux and lymphocyte count were significantly higher in the group with renal scarring (p < 0.05), and the NLR was significantly lower in the group with renal scarring (p < 0.05). The lymphocyte count was significantly higher (p < 0.05) and NLR was significantly lower in the high-grade VUR group (p < 0.05). However, MPV values did not differ significantly (p > 0.05) between the groups.

CONCLUSIONS

NLR can be used to predict renal scarring in patients with VUR, especially in the period of 3-6 months after the first attack of infection, and may even serve as a candidate marker for treatment selection. However, larger series and prospective studies are needed.

Indications for operation and results from surgical treatment of vesicoureteral reflux

The main objective of this retrospective study was to evaluate the value of surgical approach in the treatment of children with vesicoureteral reflux (VUR). Material and method: The study was conducted in the period from January 2006 to December 2014, and included children with symptomatic VUR, who were surgically treated. A total of 72 children were treated, of whom 56 were females and 16 were males, aged between 2 and 16 years. They were treated with IV and V grade reflux ureters. Thirty-two of the unilateral refluxes were left-sided, 18 right-sided and 22 both-sided. VUR was diagnosed with Voiding cystourethrography (VCUG). Cohen technique was performed in 64 (90%) patients, Politano-Lead better technique in 4 (5%) patients and Lich-Gregoir technique in 4 (5%) patients. Results: Out of the 72 treated patients, 69 had a postoperative negative finding of VUR on the performed VCUG, indicating a high 95% success rate. In three girls, persistent postoperative reflux was found in postoperative VCUG. In the first patient persistent VUR was unilateral, of  V grade. In the second patient, a third-degree VUR was found and the third patient was diagnosed with II grade VUR. Postoperatively, non-febrile UTIs (urinary tract infections) were diagnosed in 23 patients (20 female children and 3 male children) out of 72 patients in total. One female child was hospitalized with febrile UTI and 8 patients or 10% developed febrile UTI within one year of the operative treatment. Conclusion: Open surgery, despite excellent results, is used for more complicated cases, VUR grade IV – V or in previously failed cases, and it does not appear to provide definitive correction of VUR in all patients and does not prevent certain low incidence of UTI postoperatively. Non-febrile UTIs can occur several years after a surgical correction. Endoscopic treatment is an alternative treatment for VUR

Risk Factors Predicting Upper Urinary Tract Damage in Patients With Myelodysplasia: Data Analysis of 637 Cases From a Single Center

Purpose

To determine the risk factors predicting upper urinary tract (UUT) damage using a grading system for upper urinary tract dilation (UUTD) and a descriptive system for all urinary tract dysfunction (AUTD) in patients with myelodysplasia.

Methods

Six hundred thirty-seven patients with myelodysplasia were evaluated at our center from January 2008 to November 2019. Clinical data, ultrasonography, magnetic resonance urography, and video-urodynamics (VUDS) parameters were collected. Univariate and multivariate analyses were used to determine the risk factors predicting UUT damage.

Results

Three hundred eighty-three males and 254 females were included. The average course of lower urinary tract symptoms (LUTS) was 14.08±7.07 years (range, 3–31 years). The urodynamic diagnoses of all patients were as follows: detrusor overactivity, 26.8%; detrusor underactivity, 6.44%; and acontractile detrusor, 66.72%. UUT damage was determined in 66.56% of the patients. Of the patients, 28.73 % had vesicoureteral reflux (VUR) during filling (bilateral, n=50; unilateral, n=133) on fluoroscopy during VUDS testing. Two hundred thirty-four patients had UUTD (bilateral, n=203; unilateral, n=31). The occurrence of hydronephrosis based on ultrasonography was closely related to ipsilateral VUR (P<0.05). Absent of bladder sensation, long-term course of LUTS, decreased maximum cystometric capacity (MCC) and bladder compliance (BC), and increased postvoid residual urine (PVR) were shown to be independent risk factors in logistic regression analysis.

Conclusions

This retrospective study using UUTD and AUTD systems indicated that patients with myelodysplasia have a high incidence of UUT damage. Absence of bladder sensation, long-term course of LUTS, decreased MCC and BC, and increased PVR were independent risk factors predicting UUT damage.

Evaluation and Management of Neurogenic Bladder: What Is New in China?

Neurogenic bladder (NB) or neurogenic lower urinary tract dysfunction (NLUTD), a dysfunction of the urinary bladder and urethra due to disease of the central nervous system or peripheral nerves, is a major global medical and social problem. Numerous nervous system abnormalities, such as: stroke, Alzheimer's and Parkinson's diseases, traumatic spinal cord injury, spinal cord tumors, congenital spina bifida, and diabetes, can cause NB/NLUTD. There are two major types of bladder control problems associated with NB/NLUTD: the bladder becomes either overactive or underactive depending on the nature, level, and extent of nerve damage. This review specifically focuses on the diagnosis and management of NB/NLUTD in China as well as on recent efforts to treat this disease.

Diagnosis and management of urinary tract infection and vesicoureteral reflux in the neonate

Urinary tract infection (UTI) is the most common bacterial infection in febrile newborns, particularly those born prematurely and with a low birth weight. Vesicoureteral reflux (VUR) predisposes to UTI and renal scarring. Half of neonates with UTI may have only low-grade fever or no fever. Jaundice in the absence of any other symptoms or signs may be the only clinical manifestation of UTI in neonates. The urinalysis may be negative in a significant number of neonates with UTI. Newborns with UTI have a high incidence of congenital anomalies of kidney and urinary tract anomalies, and hence should undergo renal imaging.

Midterm outcomes of protection for upper urinary tract function by augmentation enterocystoplasty in patients with neurogenic bladder

PURPOSE

To evaluate the midterm outcomes of protection for upper urinary tract (UUT) function by augmentation enterocystoplasty (AE) using a grading system for upper urinary tract dilation (UUTD) and a descriptive system for all urinary tract dysfunction (AUTD) in patients with neurogenic bladder.

METHODS

We retrospectively reviewed 120 cases of AE from our database, which was collected between 2005 and 2013. UUTD grading system was developed by magnetic resonance urography (MRU), and AUTD system was described by video-urodynamics, MRU, isotope renography, etc. UUT function was evaluated by these systems before operation, and at 6, 12, 24 and 36 months postoperatively. The indication, midterm outcomes and complications were evaluated.

RESULTS

All patients had significant improvement for urodynamic parameters at 6 months postoperatively. Comparing the grades of UUTD and vesicoureteral reflux (VUR) before and after operation, the median grade of 95 UUTD ureters decreased from 3 to 0, and the percentage of 0 grade UUTD increased from 0 to 90.9 % at 36 months. The median grade of 96 VUR ureters decreased from 3 to 0, and the percentage of 0 grade VUR increased from 0 to 98.6 % at 36 months. The glomerular filtration rate of kidneys and serum creatinine level of patients had an increasing improvement after surgery.

CONCLUSIONS

The midterm follow-up using UUTD and AUTD systems indicates that AE is effective and safe for UUT protection. The patients with moderate and severe UUT deteriorations and renal function impairment resulting from VUR and UUTD have undergone the increasing improvement.

Which patients are at higher risk for residual valves after posterior urethral valve ablation?

Purpose

To find patients at high risk of obstructive remnant leaflets after valve ablation among boys with posterior urethral valve (PUV), we evaluated any possible relationship between preoperative findings in our patients and residual obstructive leaflets after valve ablation.

Materials and Methods

We retrospectively reviewed the medical records of 55 patients with PUV that was treated by the same surgeon between 2008 and 2012. Of these, 37 patients (67.3%) had no obstructive remnant leaflets (group A) and 18 patients (32.7%) had obstructive remnant leaflets (group B) in follow-up cystoscopy. Preoperative clinical and radiological findings were evaluated and compared between the groups.

Results

Among all the preoperative data we examined, the analysis revealed that age at the time of surgery (median age: group A, 15 months; group B, 7 months; p=0.017), echogenicity of kidneys (p<0.05), presence of vesicoureteral reflux (p<0.05), and grade of reflux (p<0.05) were significantly different between the groups. Method of valve ablation, anterior-posterior diameters of the renal pelvis, renal cortical thickness, bladder wall thickening, and scarring on the dimercaptosuccinic acid scan showed no significant differences between the two groups.

Conclusions

In our patients, younger age at surgery time, hyperechogenicity of renal parenchyma, presence of vesicoureteral reflux, and grade 4 or 5 reflux before surgery had a significant relationship with residual valves. More studies may result in enhanced management of patients at high risk of residual valves after PUV ablation, because the sooner the obstruction is resolved entirely, the better the outcome.

Surgical management of vesicoureteral reflux in children

Vesicoureteral reflux (VUR) is the most common uropathy affecting children. Compared to children without VUR, those with VUR have a higher rate of pyelonephritis and renal scarring following urinary tract infection (UTI). Options for treatment include observation with or without antibiotic prophylaxis and surgical repair. Surgical intervention may be necessary in patients with persistent reflux, renal scarring, and recurrent or breakthrough febrile UTI. Both open and endoscopic approaches to reflux correction are successful and reduce the occurrence of febrile UTI. Estimated success rates of open and endoscopic reflux correction are 98.1% (95% CI 95.1, 99.1) and 83.0% (95% CI 69.1, 91.4), respectively. Factors that affect the success of endoscopic injection include pre-operative reflux grade and presence of functional or anatomic bladder abnormalities including voiding dysfunction and duplicated collecting systems. Few studies have evaluated the long-term outcomes of endoscopic injection, and with variable results. In patients treated endoscopically, recurrent febrile UTI occurred in 0-21%, new renal damage in 9-12%, and recurrent reflux in 17-47.6% of treated ureters with at least 1 year follow-up. These studies highlight the need for standardized outcome reporting and longer follow-up after endoscopic treatment.

Correlations between pretransplant dialysis duration, bladder capacity, and prevalence of vesicoureteral reflux to the graft

BACKGROUND

Urinary bladder capacity is reduced in patients undergoing long-term dialysis, which may increase the risk of vesicoureteral reflux (VUR) to a transplanted kidney. This study investigated the correlations between dialysis duration, pretransplant and posttransplant bladder capacity, and prevalence of VUR to the graft.

METHODS

Voiding cystography was performed in 101 adult renal transplant recipients without neurogenic disorders immediately before and 1 year after transplantation to evaluate bladder capacity and VUR. Nonstented extravesical antireflux ureteroneocystostomy was performed in all patients.

RESULTS

The median dialysis duration and pretransplant bladder capacity were 32 months (range 1-426 months) and 120 mL (range 15-450 mL), and 21 patients (20.8%) underwent dialysis for more than 120 months, and 30 patients (29.7%) had a pretransplant bladder capacity of less than 80 mL. Dialysis duration was correlated with pretransplant bladder capacity (R=0.466, P<0.001). Bladder capacity expanded more than 6-fold from pretransplantation to posttransplantation, and all recipients had a bladder capacity greater than 150 mL at 1 year posttransplantation. Thirty patients had VUR to the graft. Dialysis duration longer than 60 months (P=0.021) and pretransplant bladder capacity of less than 130 mL (P=0.024) were associated with VUR. VUR was associated with lower graft function.

CONCLUSIONS

Although bladder capacity decreased because of long-term dialysis, it exceeded 150 mL at 1 year posttransplantation. A small bladder can be used in renal transplantation, but it may increase the risk of VUR.

ROBO2 gene variants are associated with familial vesicoureteral reflux

The SLIT2 receptor ROBO2 plays a key role in the formation of the ureteric bud, and its inactivation in mice leads to supernumerary ureteric bud development, lack of ureter remodeling, and improper insertion of the ureters into the bladder. Recently, two heterozygous ROBO2 missense mutations were identified in two families with primary vesicoureteral reflux occurring in combination with congenital anomalies of the kidney and urinary tract (VUR/CAKUT). This study investigated a possible causal role of ROBO2 gene variants in 95 unrelated patients with primary VUR (n = 78) or VUR/CAKUT. Eighty-two percent of all patients had a family history of genitourinary anomalies. Twenty-four ROBO2 gene variants were identified by direct sequencing of all 26 exons and the exon-intron boundaries. Of these, four led to amino acid substitutions: Gly328Ser, Asn515Ile, Asp766Gly, and Arg797Gln. When the families were examined, the missense variants co-segregated with VUR (three families) or VUR/CAKUT (one family). These variants were not found in 190 control subjects, and the affected amino acids have been conserved through evolution. In conclusion, a relatively high frequency of ROBO2 variants (5.1%) was found in familial cases; however, functional studies and validation in other cohorts are warranted.

A genome search for primary vesicoureteral reflux shows further evidence for genetic heterogeneity

Vesicoureteral reflux (VUR) is the most common disease of the urinary tract in children. In order to identify gene(s) involved in this complex disorder, we performed a genome-wide search in a selected sample of 31 patients with primary VUR from eight families originating from southern Italy. Sixteen additional families with 41 patients were included in a second stage. Nonparametric, affected-only linkage analysis identified four genomic areas on chromosomes 1, 3, and 4 (p < 0.05); the best result corresponded to the D3S3681-D3S1569 interval on chromosome 3 (nonparametric linkage score, NPL = 2.75, p = 0.008). This region was then saturated with 26 additional markers, tested in the complete group of 72 patients from 24 families (NPL = 2.01, p = 0.01). We identified a genomic area on 3q22.2-23, where 26 patients from six multiplex families shared overlapping haplotypes. However, we did not find evidence for a common ancestral haplotype. The region on chromosome 1 was delimited to 1p36.2-34.3 (D1S228-D1S255, max. NPL = 1.70, p = 0.03), after additional fine typing. Furthermore, on chromosome 22q11.22-12.3, patients from a single family showed excess allele sharing (NPL = 3.35, p = 0.015). Only the chromosome 3q region has been previously reported in the single genome-wide screening available for primary VUR. Our results suggest the presence of several novel loci for primary VUR, giving further evidence for the genetic heterogeneity of this disorder.

Endoscopic treatment of vesicoureteric reflux in transplanted kidneys

Twenty-one patients underwent endoscopic subureteric injection of Polytef paste for the correction of secondary vesicoureteric reflux (VUR) in transplanted kidneys. Ureteroneocystotomy was performed in renal transplants using an extravesical technique in 19 patients and the Leadbetter-Politano technique in 2 cases. Success was achieved in only 6 patients, including the 2 ureters reimplanted according to the Leadbetter-Politano technique. No significant complication relating to the technique was observed. Despite the low success rate (30%), endoscopic treatment of VUR in transplanted kidneys is justified as a first attempt in view of the morbidity of VUR and the difficulties of repeated surgical reimplantation in this population.

Inflammatory cell infiltrate in distal ureteral segments from patients with reflux

A total of 110 reimplanted ureters from 61 patients were examined by light microscopy. Twenty-four distal segments from nonrefluxing ureters were used as control group. Overall, 55 of 110 specimens (50%) had inflammatory cell infiltrates (ICI) consisting of lymphocytes and plasma cells in the submucosa and adjacent muscularis. Forty-five ureters (82%) had mild ICI, and 10 ureters (18%) had moderate or severe ICI only in patients with history of infection. ICI increased with grade of reflux in both infected and noninfected groups. Of 75 ureters (68%) from patients with history of infection, 45 (60%) had ICI. Ten of 35 ureters (29%) from patients without history of infection had ICI. A causal relationship between reflux and ICI remains speculative and needs further study.

Medical treatment of vesicoureteral reflux detected in infancy

Between 1970 and 1982, 41 neonates and infants with grades II and III vesicoureteral reflux (international classification) but with no medical or urological complications were treated medically and followed for an average of 7.5 years. In 33 of the 41 patients the vesicoureteral reflux resolved (group 1) and in 8 it persisted (group 2). The severity and frequency of urinary infection decreased to a greater degree in group 1 (p less than 0.0005) than in group 2 (p less than 0.05). There was no difference in endogenous creatinine clearance between the 2 groups. Comparison of kidney length and bipolar parenchymal thickness revealed that bipolar parenchymal thickness was significantly less in group 2 patients (p less than 0.01). Body weight tended to increase in both groups but it was greater in group 1. In both groups height was lower at the time of detection of reflux and it approached nearly normal values during followup. It is tempting to conclude that early recognition of mild forms of vesicoureteral reflux (grades II and III) and systematic medical treatment can preserve renal function and promote renal and somatic growth. However, this tendency is less pronounced in patients with persistent reflux.

Vesico-uretero-renal reflux and the kidney

The most frequent complications of non-obstructive vesico-uretero-renal reflux (VUR) are segmental renal scars. These scars are confined to segments with intrarenal reflux which are, in addition, exposed to bacterial infection. Primarily, only gaping collecting duct orifices, confined to compound papillae and mainly situated at the kidney poles, allow intrarenal reflux. Scar contraction and obstruction seem to be able to transform closed collecting duct orifices into gaping ones, thereby enlarging the parenchymal area prone to intrarenal reflux and to renal scarring. Contrary to earlier reports, a recent survey has documented that new scars in children develop with significant frequency beyond 5 years of age. There is a greater tendency for scarring to develop with more severe VUR, but new renal scars can develop with all grades of VUR. Early and adequate antibiotic treatment decreases the extent of scarring. The results of experimental studies in which renal scarring developed in piglets with bladder decompensation resulting from intravesical obstruction but without bacterial infection may be relevant to the few children with proximal urethral valves and hypertonic neurogenic bladders but not to the large number with non-neurogenic detrusor instability or detrusor sphincter dyssynergia. Prospective studies have not shown different recurrence rates of urinary tract infections in medically managed compared with surgically managed children. The frequency of acute pyelonephritic attacks decreased significantly after operation.

Is true hermaphroditism a primary germ cell disorder?

Eleven cases of true hermaphroditism, 6 raised as female and 5 as male, were seen in the 20-year period from 1965 to 1985. External genitalia varied from Prader types II to IV. The ovotestis (11/22) was the most common gonad, and a marked variation in macroscopic and microscopic appearances with five patterns of distribution of gonadal tissue was noted. Ovulation was observed in ovarian tissue, and spermatogonia, but no spermatozoa, in testicular tubules. A hypothesis is developed suggesting abnormal testicular differentiation, and a model is presented to explain observed patterns of gonadal tissue distribution. A uterus was present in all cases, but a hemiuterus or lateralized uterus was noted in the 5 cases in which only testicular or predominantly testicular tissue was observed on the contralateral side. Karyotype analysis showed 46 XX in 5 cases (1 with an H-Y antigen) and a mosaic involving 46 XY in the remaining 5. Spontaneous puberty was achieved in 3 of the females, and of the 4 males with residual testicular tissue, all are prepubertal.

Ureteral diameter in low-risk vesicoureteral reflux in infancy and childhood

In order to improve the accuracy of the grading of vesicoureteral reflux (VUR), reference values for ureteral diameter at micturition cystourethrography (MCUG) were established in infants and children with low-risk VUR. Low-risk VUR was defined as VUR not associated with infection, obstruction, calculi, duplication, malformations (except for hypospadia) or neurogenic bladder disturbances. Forty-six children (age 1 day-14 years) were selected by examining the records of 12000 MCUG:s performed 1960-1983. Ureteral diameter was measured at the widest point of the ureter on the films from MCUG:s and urographies. Ureteral diameter was slightly larger at MCUG than at urography in the same individuals but the difference was not significant. The ureteral diameter at MCUG also correlated closely to normal values at urography in a previous study. It is proposed that the reference values obtained at MCUG in the present investigation can be used for the differentiation between dilatation and no dilatation in the grading of VUR.

Normal ureteral diameter in infancy and childhood

Ureteral diameters were estimated on films from intravenous urography in 194 children (100 boys and 94 girls) aged 0-16 years. Children with signs of urinary tract infection, calculi, obstruction, duplication or malformation were excluded. Films obtained without abdominal compression were used for measurements, including only ureters visualized over 50 per cent of their lengths. A good correlation was demonstrated between ureteral diameter and age (r = 0.69) and between ureteral diameter and the length of a segment of the lumbar spine (r = 0.73). The widest part of the ureter was most often located just above the crossing of the iliac vessels. The right ureter was slightly wider than the left one. No difference between boys and girls was noted. The results are in good agreement with those of others obtained at autopsy. Bearing in mind the possible physiologic variations, it would seem that measuring the ureteral diameter can be of value for a more objective differentiation between dilated and non-dilated ureters.

International system of radiographic grading of vesicoureteric reflux. International Reflux Study in Children

The classification of grading of vesicoureteric reflux (VUR) agreed to by the participants in the International Reflux Study in Children is described. It combines two earlier classifications and is based upon the extent of filling and dilatation by VUR of the ureter, the renal pelvis and the calyces. A standardised technique of voiding cystography is also described to ensure comparability of results.