Diuretic renography in hydronephrosis: renal tissue tracer transit predicts functional course and thereby need for surgery.
OBJECTIVE
The recognition of those hydronephrotic kidneys which require therapy to preserve renal function remains difficult. We retrospectively compared the 'tissue tracer transit' (TTT) of (99m)Tc-mercaptoacetyltriglycine ((99m)Tc-MAG(3)) with 'response to furosemide stimulation' (RFS) and with 'single kidney function < 40%' (SKF < 40%) to predict functional course and thereby need for surgery.


METHODS
Fifty patients with suspected unilateral obstruction and normal contralateral kidney had 115 paired (baseline/follow-up) (99m)Tc-MAG(3) scintirenographies. Three predictions of the functional development were derived from each baseline examination: the first based on TTT (visually assessed), the second on RFS and the third on SKF < 40%. Each prediction also considered whether the patient had surgery. Possible predictions were 'better', 'worse' or 'stable' function. A comparison of SKF at baseline and follow-up verified the predictions.


RESULTS
The frequency of correct predictions for functional improvement following surgery was 8 of 10 kidneys with delayed TTT, 9 of 22 kidneys with obstructive RFS and 9 of 21 kidneys with SKF < 40%; for functional deterioration without surgery it was 2 of 3 kidneys with delayed TTT, 3 of 20 kidneys with obstructive RFS and 3 of 23 kidneys with SKF < 40%. Without surgery 67 of 70 kidneys with timely TTT maintained function. Without surgery 0 of 9 kidneys with timely TTT but obstructive RFS and only 1 of 16 kidneys with timely TTT but SKF < 40% lost function.


CONCLUSIONS
Delayed TTT appears to identify the need for therapy to preserve function of hydronephrotic kidneys, while timely TTT may exclude risk even in the presence of an obstructive RFS or SKF < 40%.
Schlotmann
Andreas
A
Department of Nuclear Medicine and Department of Radiation Oncology, University Hospital Freiburg, Hugstetter Str. 55, 79106, Freiburg, Germany. Andreas.Schlotmann@Uniklinik-Freiburg.de
Clorius
John H
JH
Clorius
Sandra N
SN
D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D002648:Child; D002675:Child, Preschool; D004232:Diuretics; D005260:Female; D005665:Furosemide; D006801:Humans; D006869:Hydronephrosis / Q000000981:diagnostic imaging* / Q000503:physiopathology / Q000601:surgery; D007223:Infant; D007231:Infant, Newborn; D007677:Kidney Function Tests / Q000379:methods; D008297:Male; D008875:Middle Aged; D008954:Models, Biological; D011866:Radioisotope Renography / Q000379:methods*; D019275:Radiopharmaceuticals; D012189:Retrospective Studies; D012307:Risk Factors; D017263:Technetium Tc 99m Mertiatide; D055815:Young Adult
D004232:Diuretics; D019275:Radiopharmaceuticals; D017263:Technetium Tc 99m Mertiatide; D005665:Furosemide