To determine the clinical symptoms and urodynamic characteristics among children with primary high-grade vesicoureteral reflux (VUR).

We prospectively studied clinical symptoms and urodynamic parameters in 147 consecutive patients ≤12 years old with idiopathic high-grade VUR referred to our hospital.

Of 147 patients with high-grade VUR, 139 cases with mean age of 5.3 years met our inclusion criteria (88.5% females, 11.5% males). The most common symptom was recurrent urinary tract infection (57%) and urgency (59%) followed by enuresis (31.6%) and frequency (26.6%). Normal urodynamic findings were observed in 23% of patients. Overactive bladder (74%), high-end filling pressure (72.7%), low-compliance bladder (56%), and low bladder capacity (51%) were the most common urodynamic reports in this study. Other urodynamic findings were underactive bladder (1.5%), hypersensitive bladder (1.5%), hyposensitive bladder (3%), and high capacity bladder (2.2%).

Proper management of VUR is very important because of its harmful potential effects on kidney function in children. With regard to the issue that most children with grade III and higher VUR had overactive bladder, high-end filling pressure, and other urodynamic disorders in their urodynamic study, it seems that these urodynamic disorders could be the basic cause of reflux.