Evaluation of renal function in children undergoing extracorporeal shock wave lithotripsy.

PURPOSE: The effect of extracorporeal shock wave lithotripsy on the growing kidneys of young children has always been a concern. We determined whether shock wave lithotripsy causes renal parenchymal scarring or affects glomerular filtration rate in children. MATERIALS AND METHODS: This prospective study included 100 children with renal stones who presented to the shock wave lithotripsy unit at our institution between March 2005 and March 2008. A total of 28 children had multiple stones in the same kidney. All children with bilateral renal stones had 1 kidney cleared of stones by percutaneous nephrolithotomy before undergoing shock wave lithotripsy. A total of 138 stones were subjected to shock wave lithotripsy. All children underwent radionuclide scan of the renal parenchyma using dimercapto-succinic acid, and glomerular filtration rate was estimated using diethylenetriamine pentaacetic acid before extracorporeal shock wave lithotripsy and 6 months afterward. Children with renal scarring due to previous surgery or vesicoureteral reflux were excluded from the study. The number of shock wave lithotripsy sessions to achieve stone-free status and the dose of shock waves used were recorded for each patient. RESULTS: No patient demonstrated renal parenchymal scarring on dimercapto-succinic acid scan or any statistically significant change in glomerular filtration rate on diethylenetriamine pentaacetic acid scan up to 6 months after shock wave lithotripsy. CONCLUSIONS: Shock wave lithotripsy is a safe modality for treating renal calculous disease in children up to 16 years old, with no impact on long-term kidney function.