Outcome Analysis of Pediatric Pyeloplasty as a Function of Patient Age, Presentation and Differential Renal Function

Abstract

We retrospectively reviewed a consecutive series of patients who underwent pyeloplasty. In all cases preoperative and postoperative isotope renal scans were performed to assess the surgical outcome with particular emphasis on the change in renal function postoperatively. The clinical records of 108 consecutive children with ureteropelvic junction obstruction were reviewed. Individual renal function was evaluated and obstruction was confirmed by diuretic assisted^99m technetium diethylenetriaminepentaacetic acid or mercaptoacetyltriglycine renography. A total of 100 pyeloplasties in 98 children between 5 days and 16 years old was included. Results were analyzed by groups according to patient age and symptoms at presentation. Drainage half-times improved in 98 percent of patients and only 1 required reoperation. Improved renal function greater than 5 percent was noted in about a third of each age group. Function remained stable in 68 percent of the kidneys and decreased in only 1. Of the improved kidneys 77 percent had impaired function preoperatively (40 percent or less of the total contribution). Those presenting with a renal mass had the greatest improvement in function. There was no statistically significant difference in improvement in renal function by age group or patient presentation. Regression analysis revealed that preoperative differential renal function was the only statistically significant predictor of improvement in renal function after pyeloplasty. Pyeloplasty in children is safe and renal functional improvement can be expected in the majority of kidneys with impaired function at presentation. However, there was no indication that early pyeloplasty in infants is more likely to result in improved function than in older children.