The Swedish reflux trial in children: v. Bladder dysfunction

We investigated the prevalence and types of lower urinary tract dysfunction in children with vesicoureteral reflux grades III and IV, and related improved dilating reflux, renal damage and recurrent urinary tract infection to dysfunction.

A total of 203 children between ages 1 to less than 2 years with reflux grades III and IV were recruited into this open, randomized, controlled, multicenter study. Voiding cystourethrography and dimercapto-succinic acid scintigraphy were done at study entry and 2-year followup. Lower urinary tract function was investigated by noninvasive methods, at study entry with 4-hour voiding observation in 148 patients and at 2 years by structured questionnaire and post-void residual flow measurement in 161.

At study entry 20% of patients had lower urinary tract dysfunction, characterized by high bladder capacity and increased post-void residual urine. At 2 years there was dysfunction in 34% of patients. Subdivision into groups characteristic of children after toilet training revealed that 9% had isolated overactive bladder and 24% had voiding phase dysfunction. There was a negative correlation between dysfunction at 2 years and improved dilating reflux (p = 0.002). Renal damage at study entry and followup was associated with lower urinary tract dysfunction at 2 years (p = 0.001). Recurrent urinary tract infections were seen in 33% of children with and in 20% without dysfunction (p = 0.084).

After toilet training a third of these children with dilating reflux had lower urinary tract dysfunction, mainly voiding phase problems. Dysfunction was associated with persistent reflux and renal damage while dysfunction at study entry did not predict the 2-year outcome.