Extracorporeal Shock Wave Lithotripsy for Renal Calculi

Purpose: To gain better understanding of ESWL (R) efficacy in children with renal calculi we report our outcomes using this technique. Materials and Methods: We reviewed the records of children who underwent ESWL as monotherapy for renal calculi at our institution from 1988 to 2007. Data included clinical characteristics, stone-free rate and its relationship to stone size and location, lithotriptor and complications. Results: The 33 boys and 29 girls with an average age of 10 years underwent a total of 69 treatments. A 53% and 63% stone-free rate was achieved after 1 and 2 ESWL sessions, respectively. A trend toward a higher stone-free rate (61% to 70%) after 1 ESWL session was seen in children with stones less than 50 mm(2) renal pelvic stones and treatment with the Dornier (R) HM3 lithotriptor. Children with stones greater than 100 mm(2), a caliceal location and those treated with the Dornier MFL 5000 lithotriptor had a higher failure rate (25% to 46%). Five patients (8%) required ureteroscopy after ESWL due to retained distal ureteral stone fragments. Five patients (8%) who were not stone-free after therapy required subsequent endoscopic treatment for the stone during followup. Conclusions: Smaller renal stones, renal pelvic calculi and treatment with an older generation lithotriptor were independent variables associated with a higher stone-free rate in children. While ESWL is a simple method in children with renal calculi, those with large or caliceal stones may do best with a primary endoscopic approach.