Nuclear Cystometrogram-Determined Bladder Pressure at Onset of Vesicoureteral Reflux Predicts Spontaneous Resolution

Objectives: The bladder pressure at the onset of reflux may reflect the competence of the ureterovesical junction. The predictive value of the bladder pressure at the onset of vesicoureteral reflux, as measured by nuclear cystometrography, was assessed relative to subsequent reflux resolution. Methods: Nuclear cystometrograms of 67 children were reviewed to determine the presence of reflux, bladder pressure at the onset of reflux, and bladder volume at the onset of reflux. The data were analyzed for significant relationships between the nuclear cystometrogram results and patient outcomes using a Cox proportional hazards regression model, controlling for the duration of follow-up and for patients with bilateral reflux. Results: Data were gathered for reflux occurring in 85 ureters. As expected, reflux of a greater grade was less likely to resolve spontaneously (P = 0.005). The pressure at the onset of reflux was also highly predictive of spontaneous resolution (P = 0.0005). Reflux occurring at greater pressures was more likely to resolve spontaneously, independent of the reflux grade or bladder volume at the onset of reflux. Patient age (P = 0.45), normalized volume of urine refluxed (P = 0.97), and normalized bladder volume at the onset of reflux (P = 0.18) were not significant predictors of reflux resolution. Conclusions: The findings of this report have demonstrated for the first time, to our knowledge, that the bladder pressure at the onset of vesicoureteral reflux, as determined by nuclear cystometrography, is a significant independent predictor of vesicoureteral reflux resolution in children.