MILD RENAL PELVIC DILATATION IS NOT PREDICTIVE OF VESICOURETERAL REFLUX IN CHILDREN

Objective. To determine if mild renal pelvic dilatation at renal ultra sound (RUS) is a reliable sign of vesicoureteral reflux (VUR) at voidi ng cystourethrogram (VCUG) in children. Materials nad methods. All pat ients less than 10 years of age who had RUS and VCUG on the same day d uring a 2-year period were identified in a computerized database. The appearance of the collecting system of each kidney was classified into two groups: group 0 - no dilatation (less than or equal to 2-mm anter oposterior dia meter of the renal pelvis) and group 1 - 3 to 10-mm AP diameter of the renal pelvis without caliectasis. VUR at VCUG was grad ed using the International Reflux Study Committee system. Results. Fou r hundred fifty-five patients (76 boys; 379 girls) with 910 kidneys we re included. VUR occurred in 268 kidneys in 174 patients. There were 8 20 group 0 kidneys and 90 group 1 kidneys. Kidneys classified as group 1 (25.0 % had reflux) were no more likely to have reflux than were ki dneys with nondistended (group 0) collecting systems (31.2 % had reflu x). There was no statistical difference in the rate of reflux in patie nts with group 1 renal pelvic distention (39.2 % refluxed) and a norma l collecting system (33.3 % refluxed) (P = 0.365). Conclusion. The fre quency of vesicoureteral reflux in children with mild renal pelvic dis tention is not significantly different than in children with no disten tion. Therefore, mild dilatation of the renal pelvis should not be con sidered an indication for voiding cystourethrography.