Routine voiding cystourethrography is of no value in neonates with unilateral multicystic dysplastic kidney.
OBJECTIVE
To determine if two successive ultrasound examinations could rule out the presence of clinically significant contralateral anomalies in neonates with multicystic dysplastic kidney (MCDK), thereby avoiding unnecessary voiding cystourethrography (VCUG).


METHODS
We followed 76 newborn infants with antenatally discovered MCDK. Two successive neonatal renal ultrasound examinations were performed, one within the first week and one at around 1 month of life. VCUG and isotopic studies were performed in all infants.


RESULTS
Urologic anomalies of the contralateral kidney were present in 19 of 76 children (25%): vesicoureteral reflux (VUR) in 16 (21%), ureteropelvic junction obstruction in 2 (3%), and renal duplex kidney in 1 (1%). Sixty-one infants (80% of total) had normal contralateral urinary tract on the 2 successive neonatal renal ultrasound scans. Among them, 4 of 61 (7%) infants presented with low-grade VUR on VCUG that had resolved spontaneously before 2 years of age. The sensitivity, specificity, positive predictive value, and negative predictive value of two successive ultrasound scans in the neonatal period to predict contralateral urological anomalies on VCUG were 75%, 95%, 80%, and 93%, respectively.


CONCLUSIONS
In infants with antenatally diagnosed MCDK, two successive normal neonatal renal ultrasound scans will rule out clinically significant contralateral anomalies, thereby rendering the need for a neonatal VCUG unnecessary.
Ismaili
Khalid
K
Department of Perinatal and Pediatric Nephrology, Hôpital Universitaire des Enfants-Reine Fabiola and Hôpital Erasme, Brussels, Belgium.
Avni
Fred E
FE
Alexander
Marc
M
Schulman
Claude
C
Collier
Frank
F
Hall
Michelle
M
D005260:Female; D006801:Humans; D007223:Infant; D007231:Infant, Newborn; D008297:Male; D021782:Multicystic Dysplastic Kidney / Q000000981:diagnostic imaging*; D011237:Predictive Value of Tests; D012042:Registries; D012680:Sensitivity and Specificity; D014463:Ultrasonography; D014517:Ureteral Obstruction / Q000175:diagnosis; D014551:Urinary Tract / Q000002:abnormalities / Q000000981:diagnostic imaging*; D014567:Urography; D014718:Vesico-Ureteral Reflux / Q000175:diagnosis