Followup of conservatively treated children with high and low grade vesicoureteral reflux: a prospective study.

A total of 202 children (mean age 31.5 +/- 23.3 months) with vesicoureteral reflux identified during the investigation that follows a urinary tract infection entered this prospective study dealing with the medical management of reflux. The diagnosis of vesicoureteral reflux was made significantly earlier in boys than in girls regardless of reflux grade (p < 0.001). At entry reflux nephropathy was present on a dimercaptosuccinic acid scan in 44% of 314 refluxing kidneys. There was no significant difference between boys and girls in the prevalence of reflux nephropathy. The renal lesions were more severe in boys independently of the grade of vesicoureteral reflux (p < 0.05). Breakthrough urinary tract infection was significantly more common in girls than in boys, regardless of vesicoureteral reflux grade (p < 0.05). Mean followup was 68.7 +/- 31.2 months. Patient age at the time of the first of 2 radionuclide cystograms without vesicoureteral reflux was considered the age of spontaneous resolution of reflux. Using life table estimations and analyzing data stratified to sex and grade of vesicoureteral reflux, we found that although reflux lasted longer in boys compared to girls, this difference was not statistically significant. During followup new scars developed in 7 patients related to breakthrough urinary tract infection. There was no significant difference between boys and girls in the development of new scars. To understand the natural history of vesicoureteral reflux children must be stratified by sex and grade of reflux.