Pyeloplasty improves renal function and somatic growth in children with ureteropelvic junction obstruction

We studied the systemic effects of pyeloplasty in 38 children with unilateral ureteropelvic junction obstruction. Mean patient age at surgery was 2.5 years and 22 patients were age 1 year or younger. Mean followup was 18 months. We recorded serum creatinine levels, glomerular filtration rate calculated by the Schwartz formula body growth, the degree of dilatation and the excretory curve of the diuresis renogram. Pyeloplasty was effective in decreasing the degree of ultrasonographic dilatation and the excretory curve of the renogram in 36 cases. Two patients required reoperation. Individual renal function improved significantly in children younger than 1 year with preoperative differential function less than 45% but not in older children. Serum creatinine level decreased significantly after pyeloplasty in all children. Likewise, glomerular filtration rate improved significantly in all children. Preoperatively, 72% of children younger than 1 year were below the 50th percentile in height. The distribution of heights became normal after surgery. Overall, percentile rank for height increased in a significant number of patients of all ages. We conclude that unilateral hydronephrosis systemically affects body growth and overall renal function, the salutary effect of pyeloplasty goes beyond the affected kidney and pyeloplasty may be of greater benefit when performed in infancy. These parameters must be considered in protocols designed to compare outcomes in children with hydronephrosis treated surgically with those who are simply observed.