Treatment of lower ureteral stones using the Dornier Compact Delta lithotripter

Lithotripsy using new-generation machines requires minimal anesthesia and so can easily be given in an outpatient setting. We report our experience with the Dornier Compact Delta lithotripter in the primary management of lower ureteral stones.

We identified 128 patients treated with SWL for lower-ureteral stones between April 1999 and August 2001. Complete follow-up was available for 112 patients. Their ages ranged from 19 to 78 years, with women accounting for 23%. Only three patients had a ureteral stent in situ. All patients were routinely followed up at 2 weeks with a plain film. The timing of further follow-up depended on the initial response to treatment.

Fragmentation occurred in 83 of 112 stones (74%): 93% of the successful cases and 43% of the unsuccessful ones. A total of 59 patients (53%) were stone free after one treatment. This figure increased to 73 (65%) after a second treatment. The mean size of the successfully treated stones was less than that of the failed stones (7.6 v 8.7 mm), although the difference did not reach statistical significance. Stone-free rates decreased as stone size increased, being 71% for the 28 stones < or =5 mm in diameter, 65% for the 52 stones 6 to 9 mm, 64% for the 25 stones 10 to 14 mm, and 42% for the 7 stones > or =15 mm.

When SWL can be delivered promptly in an outpatient setting, it remains a useful first-line treatment for lower ureteral stones. Although it is not as effective as ureteroscopy, its use can avert the need for more invasive treatment in half to two thirds of patients. It should be limited to stones <15 mm.