Effects of stents on lithotripsy of ureteral calculi: treatment results with 18,825 calculi using the Lithostar lithotriptor.

Between November 14, 1988 and August 1, 1993, 18,825 ureteral calculi were treated in the United States using 25 different mobile and 2 fixed base Siemens Lithostar lithotriptors. Lithotripsy was performed by 1,012 urologists using the modified Puigvert technique. The overall stone-free rate was 83.8% with a retreatment rate of 10.8%. The stone-free rate varied from 85.8% with stones of 10 mm. or smaller to 67.9% for stones larger than 20 mm. A ureteral stent or catheter was placed before lithotripsy in 19.3% of all treatments and 80.7% had in situ treatment without instrumentation. For calculi of any size, the use of ureteral stents or catheters had no effect on treatment outcome at any ureteral location.