[Extracorporeal shock wave lithotripsy monotherapy using Lithostar--factors influencing actuarial residual stone...

For the evaluation of post treatment course after initial extracorporeal shock wave lithotripsy (ESWL) as a monotherapy using the Lithostar, the actuarial residual stone rate (ARSR) was calculated by the Kaplan-Meier formula in 713 calculi (255 renal and 458 ureteral calculi). ARSRs in all calculi at 3, 6, 12 and 48 months were 41.6, 30.5, 20.6 and 10.3%, respectively. Significantly higher ARSRs were observed in the following former group compared to the latter: large calculi to small or middle sized calculi, renal calculi to ureteral calculi (small or middle sized), and plural renal calculi (middle sized) to single renal calculi (middle sized). There was no significant difference either between large renal and large ureteral calculi, or overall single and plural calculi. These findings show that ARSRs calculated by the Kaplan-Meier formula clearly reveal factors influencing the ESWL effects.