Long-term evolution of renal damage associated with unilateral vesicoureteral reflux

Purpose: We determined the long-term evolution of renal damage associated with vesicoureteral reflux. Materials and Methods: We retrospectively selected 74 consecutive children with unilateral primary vesicoureteral reflux, ipsilateral renal differential uptake less than 45% at dimercapto-succinic acid scintigraphy performed 4 to 6 months after urinary tract infection (60 patients) or shortly after diagnosis of vesicoureteral reflux investigated for prenatal hydronephrosis (14), and normal ultrasound and scintigraphic imaging of the contralateral nonrefluxing kidney. Average patient age at diagnosis was 3 years. The outcome was assessed via dimercapto-succinic acid scan at 5 to 24 years (mean 8.9). Results: In 65 patients (88%) variations of less than 5% in differential uptake were recorded. Three patients (4%) showed an increase of greater than 5% in differential uptake of the refluxing kidney. Six patients (8%) demonstrated a decrease of greater than 5%, of whom 3 had 1 and 3 had no febrile urinary tract infection during followup. A total of 18 patients had a differential uptake of 35% to 45% at the first visit, of whom 3 exhibited a decrease of 5.2% to 27% in differential uptake and had no history of febrile urinary tract infection. Conclusions: In most cases differential uptake of the unilaterally refluxing affected kidney remains stable from early childhood to puberty despite the increase in body mass, which necessitates increasing renal work. In some patients a significant decrease in differential uptake may be observed even in the absence of recurrent febrile urinary tract infections. A mild decrease in differential uptake (35% to 45%) at diagnosis does not exclude the possibility of a subsequent significant decrease, even in the absence of febrile urinary tract infection.