Extracorporeal shock wave lithotripsy in children: experience using two second-generation lithotripters

To assess the value of extracorporeal shock wave lithotripsy (ESWL) in treating paediatric urolithiasis, and to determine factors that may affect the results.

Using two types of lithotripters (MFL 5000, Dornier MedTech GmbH, Germany, and the Echolith, Toshiba Medical Systems, Japan), 148 children and adolescents (mean age 11.2 years, SD 4.7, range 1-18) were treated for urinary stones. Of these, 137 patients had renal stones and 11 had ureteric stones. The respective mean (SD) stone width and length were 10.2 (4.1) and 12.9 (5.6) mm for renal stones and 7.6 (2.7) and 9.1 (2.7) mm for ureteric stones. The patients were assessed 3 months after treatment and the results compared using the chi-square test to detect factors that might be associated with the stone-free rate.

For those with renal stones, the overall stone-free rate was 86% and the re-treatment rate 64%. The only significant factor associated with the stone-free rate was the transverse diameter of the stone (P = 0.012); there was no significant effect of the type of lithotripter but there was a significant difference in re-treatment rate (P = 0.016) in favour of the MFL 5000. All those with ureteric stones were rendered stone-free and only four required re-treatment. Only one child among those with renal stones developed steinstrasse; this was managed by ureteroscopy and otherwise no other complications were recorded in either group.

ESWL is a safe and effective treatment for paediatric urolithiasis. The stone-free rate is influenced significantly by stone size. The re-treatment rate differed significantly between the electrohydraulic and piezoelectric lithotripters, but the stone-free rate did not.