The significance of detrusor wall thickness as a prognostic factor in pediatric bladder outlet obstruction

Purpose: The purpose of this study is to determine detrusor thickness as a prognostic factor in posterior urethral valves. Methods: The medical information of 41 patients diagnosed with posterior urethral valves at our institute was retrospectively reviewed. The serum creatinine level after bladder decompression, results of ultrasonography, and voiding cystourethrography were compared between groups divided according to the final bladder and renal function. Detrusor thickness was measured using Müller's method. Results: The median detrusor thickness was 1.3 mm (0.4-2.5 mm). After median 45.6 months (7.2-96.0 months) of follow-up, impaired bladder function (IBF) was observed in 14 patients. In multivariate analysis, detrusor thickness greater than 1.3 mm (odds ratio, 32.6; 95% confidence interval, 3.1-340.6; P =.004) was the only independent risk factor for later IBF. Final renal function impairment developed in 24 patients (58.5%), and 3 patients (7.3%) were diagnosed with end-stage renal disease after median 66.0 months (32.4-133.2 months) of follow-up period. On multivariate analysis, age-specific elevated serum creatinine level at presentation (odds ratio, 11.1; 95% confidence interval, 1.1-112.5; P =.042) was an independent risk factor. Conclusions: Detrusor thickness more than 1.3 mm on ultrasonography was an independent prognostic factor for later IBF.