Ultrasonographic measurement of bladder wall thickness as a risk factor for upper urinary tract deterioration in children with myelodysplasia

Purpose: We investigated the correlations between ultrasonographic bladder wall thickness and urodynamic parameters, and estimated the diagnostic accuracy of bladder wall thickness for predicting unfavorable urodynamic patterns in children with myelodysplasia. Materials and Methods: A total of 57 children (median age 5.1 years.) with myelodysplasia were enrolled in the study. All children underwent ultrasonography to measure bladder wall thickness. Videourodynamic evaluation was also performed within 3 months of ultrasound assessment. Bladder wall thickness was compared to urodynamic data. A urodynamic risk of upper urinary tract deterioration was defined as maximum detrusor pressure greater than 40 cm H2O during filling or at leakage, or sphincter dyssynergia during voiding. Results: Bladder wall thickness was significantly correlated to detrusor leak point pressure, maximum amplitude of detrusor overactivity and maximum detrusor pressure during storage phase. In 16 children who had unfavorable urodynamic risk patterns the mean bladder wall thickness was 3.9 +/- 1.0 mm, compared to 2.4 +/- 0.7 mm. in 41 patients with favorable urodynamic patterns. There was a significant difference between bladder wall thickness in children with and those without urodynamic risk factors (p < 0.001). For a diagnosis of unfavorable urodynamic patterns bladder wall thickness greater than 3.3 mm had a positive predictive value of 85.7%, a negative predictive value of 90.7%, specificity of 75.0% and sensitivity of 95.1%. Receiver operator characteristic analysis revealed that bladder wall thickness had a high predictive value for unfavorable urodynamic patterns, with an area under the curve of 0.908. Conclusions: Ultrasonographic assessment of bladder wall thickness is a sensitive screening tool for the diagnosis of urodynamic risk factors for upper urinary tract deterioration in children with myelodysplasia.