Bladder height width ratio on voiding cystourethrogram as a predictor of future valve bladder in children with posterior urethral valve.

BACKGROUND/AIMS: Prompt and early treatment of valve bladder is known to improve renal outcome in patients with PUV. We hypothesized that bladder height width ratio (HWR) measurement on voiding cystourethrogram (VCUG) could predict development of valve bladder. METHODS: All patients who underwent primary PUV ablation and evaluated later with urodynamics were included. Valve bladder was suspected when there were daytime wetting, persistent hydroureteronephrosis, and elevated detrusor pressures on urodynamics. VCUGs were analysed for HWR: maximum height/width of bladder. ROC curve analysis was performed to identify HWR that could predict development of urodynamic abnormality. RESULTS: Between 2012 and 2017, 102 patients were studied: median age at valve ablation 25 days (3-125 days); follow-up 5 years (3-7 years). The ROC curve comparing post-ablation HWR with occurrence of valve bladder showed a cut-off of 1.45 (AUC 0.93). HWR cut-off of 1.45 had a sensitivity of 89% and specificity of 84% in predicting future valve bladder. Detrusor overactivity was noticed on urodynamics in 41/55 (74%) of those with HWR > 1.45 compared 5/47 (11%) in those with HWR < 1.45 (p = 0.001). CONCLUSION: Bladder height width ratio on VCUG is a useful parameter to predict development of future valve bladder in children with PUV.