INCREASED RENAL-FUNCTION IN KIDNEYS WITH URETEROPELVIC JUNCTION OBSTRUCTION - FACT OR ARTIFACT - ASSESSMENT BY QUANTITATIVE SINGLE-PHOTON EMISSION COMPUTERIZED-TOMOGRAPHY OF DIMERCAPTO-SUCCINIC ACID UPTAKE BY THE KIDNEYS
D. Groshar et al., INCREASED RENAL-FUNCTION IN KIDNEYS WITH URETEROPELVIC JUNCTION OBSTRUCTION - FACT OR ARTIFACT - ASSESSMENT BY QUANTITATIVE SINGLE-PHOTON EMISSION COMPUTERIZED-TOMOGRAPHY OF DIMERCAPTO-SUCCINIC ACID UPTAKE BY THE KIDNEYS, The Journal of urology, 155(3), 1996, pp. 844-846
Purpose: We evaluated whether increased differential renal function on
the pentetic acid (DTPA) renogram represents elevated renal function
in obstructed kidneys. Materials and Methods: In 10 patients with unil
ateral ureteropelvic junction obstruction and a differential function
of 53% or greater on the DTPA renogram of the obstructed kidney we per
formed quantitative single photon emission computerized tomography of
dimercapto-succinic acid uptake by the kidneys. Results: The absolute
uptake of dimercapto-succinic acid was significantly higher in the obs
tructed kidneys compared to the contralateral normal kidneys (30.0% +/
- 7.9 versus 25.3% +/- 8.3, t = 3.6, p <0.01, respectively). The eleva
ted absolute uptake in the obstructed kidneys was due to an increased
functional volume compared to the contralateral normal kidneys (126.0
+/- 69.7 cc versus 102.3 +/- 59.2 cc, t = 4.4, p <0.01, respectively).
Conclusions: The results suggest that increased relative renal functi
on in hydronephrotic kidneys due to ureteropelvic junction obstruction
is not an artifact of the DTPA renogram. It may represent a compensat
ory mechanism that sometimes may overcompensate resulting in a paradox
ical hyperfunctioning kidney.