Dissolution therapy versus shock wave lithotripsy for radiolucent renal stones in children: a prospective study

Abstract

Purpose: We prospectively evaluated the efficacy of dissolution therapy and standard shock wave lithotripsy as a noninvasive modality for radiolucent renal stones in children.

Materials and methods: A total of 87 children with radiolucent renal calculi were included in study. Median age was 2.5 years (range 0.5 to 13). Computerized tomography was done to confirm a stone density of less than 500 HU. Median stone length was 12 mm (range 7 to 24). Patients were randomly divided into 2 groups. The medical group of 48 patients received potassium sodium hydrogen citrate at a dose of 1 mEq/kg per day for 1 to 3 months. The shock wave lithotripsy group of 39 patients were treated with a Lithotripter S (Dornier Medtech, Kennesaw, Georgia) while under general anesthesia. Complications in each group were recorded. Patients were considered stone free when imaging within 3 months showed no evidence of stones.

Results: The stone-free rate was 72.9% for dissolution therapy vs 82.1% after a single session of shock wave lithotripsy (p = 0.314). One patient per group experienced a pyelonephritis episode during followup (p = 0.698). Three of the 13 patients in whom medical regimens failed were noncompliant and 5 ingested the medication sporadically.

Conclusions: Medical dissolution therapy is a well tolerated, effective treatment for radiolucent renal stones in children. It eliminates the need for shock wave lithotripsy in up to 73% of cases.

Keywords: kidney; lithotripsy; nephrolithiasis; outcome assessment; potassium citrate.