|
PEDIATRIC
UROLOGY
Abnormal renal scans and decreased early resolution of low grade
vesicoureteral reflux
Nepple KG, Knudson MJ, Austin JC, Cooper CS
Division of Pediatric Urology, University of Iowa, Iowa City, Iowa, USA
J Urol. 2008; 180: 1643-7
-
Purpose:
Limited studies suggest a relationship between scarring on renal
scan and failure to resolve vesicoureteral reflux. We evaluated
the impact of abnormal renal scans on early vesicoureteral reflux
resolution.
Materials and Methods: The medical records and renal scans were
reviewed of children diagnosed with primary reflux between 1988
and 2004. We defined an abnormal renal scan as renal scarring or
relative renal function 40% or less. Reflux resolution was noted
1 and 2 years after diagnosis.
Results: Renal scan data were available on 161 children with vesicoureteral
reflux, including 127 girls and 34 boys. Relative renal function
was 15% or less in 7 children, 16% to 35% in 14, 36% to 40% in 18
and greater than 40% in 122. Of the 161 patients 79 (43%) had an
abnormal renal scan, including 37% with grades 1 to 3 reflux. The
rate of 2-year reflux resolution in the abnormal and normal renal
scan groups was 13% vs 53%. Of children with grades II and III reflux
those with an abnormal renal scan were less likely to have reflux
resolution compared to those with normal renal scans (23% vs 55%
and 4% vs 41, respectively, p <0.05). The same relationship was
present at 1 year for grades 2 and 3 (18% vs 49% and 4% vs 30, respectively,
p <0.05).
Conclusions: Abnormal renal scans are an important independent predictor
of early failure to resolve vesicoureteral reflux. An abnormal renal
scan should be considered when counseling families about the likelihood
of early reflux resolution. Performing a renal scan may be indicated
in select patients.
- Editorial
Comment
This research deals with 16 years of reflux studies in which patients
had a renal scan and a VCUG. Demographic variables as well as voiding
dysfunction were noted and compared. One hundred and sixty-one patients
had a renal scan and all of the recurred data for the study. Four
different kinds of renal scans were used over this long data collection
period, including glucoheptonate, Mag3, DMSA and DPTA. Relative
renal function was judged to be poor if it were less than 40% and
abnormal renal scans were noted if there were renal scars, even
if the relative renal function was normal.
Seventy children, 43.5%, had abnormal renal scans and 91 children
had normal renal scans. Boys had a few more abnormal renal scans
than girls did but this did not reach statistical significance.
The incidence of voiding dysfunction between normal and abnormal
renal scans was the same. Abnormal renal scans were more prevalent
in higher grades of reflux and this reached a p value of less than
0.001. There was not a statistical difference between different
kinds of renal scans.
Reflux spontaneous resolution rate was 29.8% at 1 year and 35.4%
at 2 years and 33 children in the study group underwent corrective
surgery within the first two years. Of the patients with diminished
relative renal function, 10% had VUR resolution and in the normal
renal function group, 43% had resolution with p value of less the
0.001. Reflux grades were not compared in Grade IV and V patients
because so many of them had abnormal renal scans and the resolution
rate had a negative correlation with the abnormal renal scans in
Grade I-III. None of the patients with abnormal renal scans and
voiding dysfunction had resolution in the first 2 years.
The management of vesicoureteral reflux is multifaceted and the
time where the greater the reflux allowed simple surgical decisions
to be made is long past. This study shows that previous kidney scarring
for relative poor kidney function has an impact on vesicoureteral
reflux resolution at least in the first two years. This study unfortunately
used four different kinds of renal scans but this did not seem to
alter the statistics. It is probably best at this time to recognize
that preventing the kidney scars is the purpose of reflux treatment
and reflux is only one factor to consider among others such as kidney
scarring and bladder dysfunction.
The longest follow up was two years and it would be most interesting
to see what the five-year follow up data would be.
Dr.
Brent W. Snow
Division of Urology
University of Utah Health Sci Ctr
Salt Lake City, Utah, USA
E-mail: brent.snow@hsc.utah.edu
|