Four-hour voiding observation in young boys with posterior urethral valves

Purpose: We evaluated 4-hour voiding observation as a method of basic assessment of bladder dysfunction in young boys with posterior urethral valves. Materials and Methods: Voiding pattern, including number of voids, voided and residual urine volume, and bladder capacity, was determined noninvasively in 24 boys younger than 4 years with posterior urethral valves and compared to that of healthy age matched controls. Results were then compared to those of standard cystometry. Results: The number of voids was higher, voided volume was smaller and residual urine volume was higher in the posterior urethral valve group. There was no difference in voiding pattern before and after removal of the anatomical obstruction. Voided and residual urine volume, and bladder capacity were higher on standard cystometry than on voiding observation. Conclusions: Four-hour voiding observation is an easy noninvasive method that focuses on emptying difficulties and clearly detects differences in voiding patterns between boys with posterior urethral valves and healthy, nontoilet trained children. We recommend the method as a complement to standard cystometry for the diagnosis and followup of bladder dysfunction in young boys with posterior urethral valves to identify the need for treatment.