Radiolucent renal stones in children: combined use of shock wave lithotripsy and dissolution therapy.

Objectives: To provide a noninvasive efficient modality for the treatment of radiolucent renal stones in children. Uric acid calculi comprise a significant proportion of urinary stones.

Methods: This study included 24 children (10 girls and 14 boys) with radiolucent renal stones. Of the 24 patients, 5 presented with bilateral renal stones, 8 with multiple stones, 4 with staghorn stones, and 7 with a solitary renal stone. Their age range was 2-12 years (mean 6.3 +/- 2.8). The stone size range was 12-65 mm in the largest diameter. All patients were treated with combined extracorporeal shock wave lithotripsy (ESWL) and medical therapy in the form of urinary alkalization using potassium sodium hydrogen citrate and allopurinol for the treatment of hyperuricosuria. Before ESWL, 3 patients had a percutaneous nephrostomy tube inserted and 2 patients had a ureteral stent placed to relieve obstruction. ESWL was performed with a Siemens Lithostar using either general anesthesia or intravenous sedation. The follow-up period after stone clearance was 12-36 months (mean 26 +/- 7.2).

Results: The stone-free rate of 100% was achieved in all 24 patients after 3 months of combined use of extracorporeal shock wave lithotripsy and dissolution therapy.

Conclusions: Combined ESWL and dissolution therapy accelerated stone clearance and delayed stone recurrence. The use of ESWL and medical therapy as a combined modality is a safe and effective treatment of radiolucent renal stones in children.