Low success rate of repeat shock wave lithotripsy for ureteral stones after failed initial treatment

Purpose: We determined the number of shock wave lithotripsy treatments that should be given for a single ureteral stone before alternate modalities ar e used. Materials and Methods: We compared the stone-free rate of initial shock wav e lithotripsy for ureteral calculi with that of subsequent treatments. We e valuated 1,593 ureteral stones treated with the Dornier MFL 5000 lithotript or* from January 1, 1994 to September 1, 1999 using various parameters asso ciated with treatment outcome. Results: The stone-free rate after initial treatment was 68% (1,086 of 1,59 3 stones), which decreased to 46% (126 of 273) after re-treatment i. We obs erved a further decrease in the stone-free rate after re-treatment 2 to 31% (19 of 61 stones, p = 0.001). The cumulative stone-free rate increased to 76% (1,212 of 1,593 stones) after 2 treatments and to 77% (1,231 of 1593) a fter 3. The stone-free rate for stones 10 mm. or less was significantly bet ter than that of stones 11 to 20 mm. initially (64% versus 43%) and after r e-treatment (49% versus 37%). A ureteral stent decreased the stone-free rat e of initial treatment and re-treatment 1 by 12% and 14%, respectively (p = 0.001). After initial treatment the stone-free rate of the upper and mid u reter was significantly higher than that of the lower ureter. Patient weigh t had no significant impact on success in either group. Conclusions: The stone-free rate of re-treating ureteral calculi with shock wave lithotripsy decreases significantly after the initial treatment. Thes e findings imply that ureteroscopic management of ureteral stones may be be tter than shock wave lithotripsy after initial shock wave lithotripsy fails .