RENAL HISTOLOGY IN URETEROPELVIC JUNCTION OBSTRUCTION: ARE HISTOLOGICAL CHANGES A CONSEQUENCE OF HYPERFILTRATION?

AbstractPurpose: There are few reports of pathological kidney findings in ureteropelvic junction obstruction in pediatric patients. The role of hyperfiltration in the genesis and progression of these changes has been a matter of debate. We determine whether segmental sclerosis is evidence of hyperfiltration and renal damage in children who underwent surgery for ureteropelvic junction obstruction.Materials and Methods: We retrospectively analyzed the clinical records of 38 children with a mean age of 4.4 years with ureteropelvic junction obstruction. Histological changes in biopsies (39 renal units) and nephrectomy specimens (2 renal units) were compared with clinical history, imaging studies and urinary protein excretion.Results: Renal histology was essentially normal in 75% of the biopsies. Focal dilatation of Bowman's space and occasionally of the collecting tubules was noted in a third of this group. Abnormal changes consistent with renal damage were present in 25% of the biopsies, including variable d...