The interrelationship between bladder-filling behavior and ureteral delivery of urine into the bladder was studied in myelodysplastic children, in a primate neurogenic bladder-dysfunction model, and in a feline obstructive-uropathy model. All of these studies confirm the observation that intravesical pressure is the most important obstacle to ureteral delivery of urine into the bladder. Our concepts of ureteral function may need some revision. The findings in the obstructive feline model suggest that we should measure ureteral delivery of urine into the bladder in relation to intravesical pressure since this method may define ureteral reserve "power" better than either perfusion studies or dynamic renal scans.
