G. Capolicchio et al., Supranormal renographic differential renal function in congenital hydronephrosis: Fact, not artifact, J UROL, 161(4), 1999, pp. 1290-1294
Purpose: Children with unilateral hydronephrosis, who had been prospectivel
y examined with diethylenetriaminepentaacetic acid (DTPA) and dimercapto-su
ccinic acid (DMSA) renography, were evaluated to determine whether supranor
mal renographic differential renal function exists.
Materials and Methods: A total of 54 children with congenital single system
hydronephrosis underwent abdominal ultrasound, voiding cystourethrogram, a
nd DTPA and DMSA renal scans, None had abnormalities of the bladder or cont
ralateral kidney. Differential renal function greater than 55% was defined
as supranormal,
Results: Of the 54 patients 15 (28%) with a median age of 4 months (range 0
.5 to 66) were identified with supranormal renographic renal function on ei
ther DTPA or DMSA. Supranormal renographic renal function was detected by D
MSA in 9 cases (mean 57 +/- 2%), DTPA in 8 (mean 58 +/- 2%) and both in 2 (
mean 57 +/- 2%), Average function demonstrated in the 15 patients was 55 +/
- 3% (range 51 to 62) with DMSA which was not different from that found wit
h DTPA (mean 55 +/- 4%, range 46 to 61%). The kidneys with supranormal reno
graphic renal function were significantly larger than hydronephrotic contro
ls according to longitudinal parenchymal area on DMSA, Mean followup was 20
months for 13 patients, with 8 of 13 (62%) undergoing pyeloplasty. Followu
p DTPA renal scans available in 9 children revealed persistent supranormal
function in 6, despite pyeloplasty in 3,
Conclusions: Supranormal renographic differential renal function does exist
in congenital hydronephrosis and when found the kidneys are consistently e
nlarged, The position of supranormal renographic renal function in the mana
gement algorithm of hydronephrosis remains to be elucidated as it does not
appear to be a benign prognostic factor.