Indian Pediatrics 2007; 44:128-130
Primary Vesicoureteral Reflux in Iranian Children
Fateme Ghane Sharbaf, Mohamad Hosein Fallahzadeh*, Ali Reza Modarresi, Mohamad Esmaeili
From the Department of Pediatrics, Dr. Sheikh Hospital, Mashhad University of Medical Science and Nemazee Hsopital, Shiraz University of Medical Sciences, Iran.
Correspondence to: Dr. F. Ghane, Dr. Sheikh Pediatric
Hospital, Tabodi Ave., Mashhad, Iran.
Manuscript received: August 18, 2005; Initial review
completed: December 15, 2005;
Vesicoureteral reflux (VUR) is defined as the backup of urine from the bladder to the ureters and is a risk factor for pyelonephritis. Primary VUR is congenital and is not associated with any underling neuromuscular or obstructive phenomen(1). Primary VUR is usually detected during radiological evaluation of children with urinary tract infection (UTI). It can also be identified in the uninfected siblings or offspring of the index patients and with prenatal diagnosis of hydronephrosis(2).
Complications such as renal scarring, chronic renal failure and hypertension are well known in patients with VUR and UTI. Antireflux surgery offers no short-term advantages other than abolishing the reflux. It also does not result in improved renal function or renal growth, and does not affect the rate of new scar formation or the incidence of hypertension. To evaluate the outcome of primary VUR, complications and the rate of recurrence of UTI, we reviewed the charts of 330 patients with VUR who were treated and followed at a university center in Mashhad and Shiraz, Iran.
Subjects and Methods
The medical charts of all the patients with primary VUR during the last 19 years (1985-2004) in Mashhad and Shiraz, Iran were reviewed. Patients with VUR secondary to lower urinary tract obstruction, neurogenic bladder, bladder diverti-culum or nonneurogenic neurogenic bladder were excluded. Of the 330 children with primary VUR, 319 who had conventional voiding cysto-urethrogram (VCUG) were included in this study. UTI were considered in presence of defined positive urinary culture and urinalysis (Pyuria and positive nitrite) in symptomatic patients. Urine culture was considered positive when two consecutive cultures showed a growth of more than 100,000 colony-forming units/mL of one microorganism in clean-catch midstream specimens in children with urinary control, and urine collected by sterile bags in those without it. Follow-up urine cultures were done within an interval of 1-3 months or at any time when a fever of unknown origin or urinary symptoms appeared. Positive urine culture in symptom free cases (asymptomatic bacteriuria) was not considered as UTI. Ultrasonography was performed in all, dimercaptosuccinic acid (DMSA) renal scan in 157 and follow-up VCUG (with a mean interval of 2 years) in 147 cases. DMSA scan performed at least 6 months later than acute UTI. Renal scarring was defined as an area of photon deficiency or small sized hypofunctioning kidney on DMSA or renal parenchymal thining on ultrasonogram. Antireflux surgery was done in 46 (14.7%) of the patients (17 with grade V, 12 with grade IV, 10 with grade III and 7 with grade II). Most (93%) of the patients received prophylactic antibiotics (Table I). Statistical analysis was done using c2 and the Student’s t-tests.
There were 479 refluxing ureters of 319 patients; 50% cases were bilateral. The age at diagnosis ranged from 54 days to 16 years (mean: 4.1 years) and the male-to-female ratio was 0.21 (girls = 262, boys = 57) (p = 0.002). In 95% patients VUR was found during the investigation for UTI. In 4.5% of the patients positive family history was the main clue for the investigation. In 90.5% of the patients the isolated microorganism in the first episode of UTI was E. coli. The initial grading of VUR, prophylactic antibiotic administration and the rate of recurrence of UTI in different grades of reflux is shown in Table I. The risk of recurrent of UTI was not significant in different grades of VUR with or without surgery.
TABLE 1 Number of Patients Using Prophylactic Antibiotics and Recurrence of UTI in Different Grades of VUR
DMSA showed cortical scars in 76 (48.4%) patients. Follow-up VCUG done in 150 (47.9%) of the patients (mean interval: 2.2 years), showed no VUR in 55%, lower grades of VUR in 27.5%, higher grades in 5.5% and no change in 12% of these patients. Anti-reflux operation was performed in 7, 10, 13 and 16 patients with VUR of grades II to V, respectively. Long term complication such as chronic renal failure and hypertension were occurred in 13 patients each (Table II). Renal scarring was found by ultrasonography in 21 and by DMSA scan in 76 patients. Of 76 patients with renal scan 55 were girls and 21 were boys. The frequencies of grades (I to V) of VUR were 4, 12, 17, 20 and 22, respectively. Fifteen patients, showed bilateral scars in VUR of grades IV and V renal scars were seen in 60% boys and 37.5% in girls (p = 0.006). Taking all grades together, renal scaring was present in 52% of boys and 29% of girls (p= 0.001).
TABLE II Complications of VUR in Relation to Treatment Groups
*Reflux was bilateral in 36 (73.5%) and 125 (47.5%) patients treated surgically and medically respectively.
Primary VUR is the most common hereditary disorder of
the genitourinary tract and is transmitted in an autosomal dominant
fashion(3). Its grading VUR is important because the natural history and
the risk of renal damage differ in different grades(4). Patients with
high grade VUR (IV and V) are 4 to 6 times more likely to develop
scarring than those with low or moderate (I to III) grade VUR and 8 to
10 times more likely to do so as compared to those without VUR(5). In
this study, 21% of the kidneys with scaring had lower grades of VUR. It
is probable that these lesions are of pyelonephritis as reported by
other works(6). In patients with higher grades of reflux the lesions may
be due to both VUR and pyelonephritis or at least in some, associated
with congenital defects of the kidney. In one study, severe VUR
diagnosed at birth was associated with congenital renal damage and males
were affected more often and more severely than females(7). Our results
are similar to this report in many aspects, including the frequency of
bilateral lesions. In contrast to several previous reports the male to
female ratio in our study is surprisingly different(7-10). It is notable
that girls out-numbered boys in this study; nevertheless kidney scar
formation was for more common in the latter group. While the rate of
renal damage in the present study was lower than that in some previous
reports(11-13), it was higher than the rate reported in Chinese children
(28% boys and 11% girls)(14). We found that the risk of renal scaring in
boys was 52%. We performed DMSA scan in the high risk cases, so some
patients with minor defect might have been missed. Despite this fact,
the high proportion of renal damage in the boys was a matter of concern
which might be explained by higher grades of VUR. As anticipated, we
observed higher rate of renal damage in the surgically treated group.
This could be due to the fact that surgical intervention was implemented
predominantly in higher grades of VUR. In 16 patients the renal scar was
documented before the antireflux operation was performed and in 9
patients it was found after the surgery. Although VCUG was not repeated
in some of the low risk patients in whom resolution of the VUR was more
predictable, the total number of cure, improvement or spontaneous
recovery was more than 80%. This is significant as compared to the
results of other reports(9,12).