Renal bladder ultrasound evaluation in monosymptomatic primary nocturnal enuresis: is it really necessary?

Published guidelines regarding radiographic imaging in the evaluation of monosymptomatic primary nocturnal enuresis (MPNE) are not followed. We aimed to evaluate the prevalence of urological abnormalities on renal/bladder ultrasound (RBUS) in children with MPNE and to compare the RBUS findings in children with and without MPNE.

Retrospective data collection in all children aged 5-17 years seen for the initial evaluation of MPNE. Control group consisted of age- and sex-matched children who had abdominal ultrasound for other than bladder-/kidney-related causes. RBUS findings were analyzed with regard to the need for intervention and/or follow-up.

While abnormalities on RBUS were seen in 12.54% of enuretic children and in 5.38% of controls (p = 0.004), the majority of these findings were clinically insignificant. Of those with abnormalities, only 4 enuretic children (1.43%) required intervention and 8 (2.87%) needed follow-up studies. These rates were not significantly different from the controls. However, enuretic children with RBUS abnormalities appear to be more resistant to treatment than enuretic children with normal RBUS (p = 0.002).

A small proportion of abnormalities seen on RBUS in children with MPNE require intervention and/or further evaluation. The identification of insignificant RBUS findings could lead to unnecessary additional investigations owing to parental concern. Detailed history and a voiding diary may be sufficient in the initial evaluation of children with MPNE, although RBUS may play an important role in patients who are resistant to treatment.