When is it necessary to perform nuclear renography in patients with a unilateral neonatal hydronephrosis?

• Published in: Journal of pediatric urology Vol. 3; p. S68
• Main Author: Berk BURGU, Susan HABELT, Naveed AHMAD , Warren SNODGRASS, Linda BAKER, Clanton HARRISON and Duncan WILCOX
• Format: Journal Article
• Language: English
• Published: Elsevier Ltd 2007
• Subjects: Pediatrics; Urology
• ISSN: 1477-5131; 1873-4898
• DOI: 10.1016/j.jpurol.2007.01.119

PURPOSE Prenatally diagnosed hydronephrosis is common and frequently resolves but most patients undergo extensive radiological investigations. We hypothesize that the anteroposterior pelvic diameter(APD) in the transverse plane on postnatal renal sonography (US) can predict both initial renal function and a deterioration in function. MATERIAL AND METHODS 88 patients with unilateral prenatal hydronephrosis,were evaluated. ROC curves were generated(SPSS 13.0) to find cutoff values for initial APD and change in APD based on initial renal function and outcome. Reduction of 5% or more was considered as a deterioration in function. All had an initial US scan at 3.6 (+/-0.8) weeks and nuclear renogram at 14.8(+/-2.8) weeks. All had a second US at 10.4 (+/-3.1) weeks. 48 patients had a second renogram. RESULTS The initial mean APD was 20.9 (10.6-49.4) mm. When the APD was less than 20 mm all kidneys had a function of 40% or greater. When APD was less than 14.8 mm the function was 45% or more. All SFU grade1 and 2 kidneys had a renal function of greater than 40%. When APD was constant or decreased then 87.5% had stable function, including patients with calyceal dilatation. If APD decreased by 4.8 mm or more then all had stable function. CONCLUSIONS If APD is less than 20 mm without significant calyceal dilatation then renal function should be greater than 40%. As this is frequently used as the cut off for surgery, patients with pelvic diameter less than 20 mm (SFU grades 1/2) don't require renography. When APD is stable or decreases significant deterioration is unlikely.