Home uroflowmetry for the evaluation of boys with urinary incontinence

Abstract

Purpose: We recorded uroflowmetry at home in boys with urinary incontinence and correlated the results with videourodynamics.

Materials and methods: Thirty-nine boys (mean age 8.4 +/- 2.0 years) with urinary incontinence underwent home uroflowmetry for 1 weekend. Artifactual spikes in 1 or more uroflow curves were present in 16 home uroflowmetry recordings. One patient, in whom none of the uroflow curves was interpretable, was excluded from the study. Of the remaining 38 boys 18 had monosymptomatic nocturnal enuresis, and 20 had nocturnal enuresis and diurnal voiding symptoms. Percentage expected bladder capacity is defined as functional/expected bladder capacity x 100%. Normal and obstructive home uroflowmetry levels are defined as functional bladder capacity at least 50% expected bladder capacity associated with multiple bell-shaped and obstructive uroflow curves, respectively. Small functional bladder capacity is defined as capacity less than 50% expected bladder capacity, regardless of uroflow patterns. Videourodynamics and cystoscopy were performed in 17 patients.

Results: Normal home uroflowmetry was noted in 5 patients (13%), obstructive uropathy in 8 (21%) and small functional bladder capacity in 25 (66%). Urodynamically 3 boys with normal home uroflowmetry had normal voiding, and 6 with obstructive home uroflowmetry had bladder outlet obstruction (of whom 1 also had detrusor overactivity). In addition, of 8 boys with small functional bladder capacity 4 had detrusor overactivity, 3 had bladder outlet obstruction and 1 had both findings.

Conclusions: Normal home uroflowmetry predicted normal voiding, and abnormal recordings implied abnormal voiding function in boys with incontinence. Bladder outlet obstruction and detrusor overactivity were frequently disclosed by obstructive home uroflowmetry and small functional bladder capacity.