Percutaneous studies of the upper urinary tract in children, with special emphasis on infants.

Of 101 antegrade pyelography and/or percutaneous nephrostomy procedures performed within a 6-year period, 18 involved patients less than 6 months of age. The procedures in this age group were characterized by ease of performance -without sedation in the neonates and with sedation in the children -and by the use of smaller needles and catheters. The procedures enabled differentiation between obstructed and nonobstructed dilated systems with pressure-flow studies, depiction of the intimate anatomy of complicated urologic abnormalities, temporary drainage, decompression of pyonephrosis, endourologic access, and collection of urine for cultures after ureterosigmoidostomy. The procedures were highly successful and had few complications.