Comparison of urodynamic and free voiding pattern in infants with dilating reflux

Purpose: We compared simultaneous investigations of free voiding pattern and urodynamic assessment in infants with dilating reflux to obtain further information on previously suspected bladder dysfunction based on abnormal urodynamic findings. Material and Methods: A total of 33 male and 8 female infants with dilating reflux were included in the study. Free voiding pattern was determined by 4-hour voiding observation compared to previously described voiding pattern studies of healthy infants. Simultaneous invasive urodynamic assessments were performed. Results: The patients were grouped according to urodynamic bladder capacity. Half of the male patients had low bladder capacity with high voiding pressure levels (hypercontractile) and the other half had either normal or high capacity bladders. The low capacity group had frequent small voids and a high rate of interrupted voiding, the high capacity group had infrequent voids of high volumes with high residual urine, and the pattern of the normal capacity group differed only from that of healthy infants by an increase in residual urine. All female infants had the typical characteristics of high capacity bladder on free voiding and urodynamic assessments. Conclusions: Infants with abnormal invasive urodynamic investigations, including those with a small capacity hypercontractile bladder and those with a high capacity bladder, could be identified on free voiding studies, indicating that an abnormal urodynamic pattern represents bladder dysfunction.