The Dornier Compact Delta lithotripter: the first 500 renal calculi

Extracorporeal Shockwave Lithotripsy (SWL) is now the best noninvasive treatment for renal calculi, rendering many patients stone free. This prospective study was performed to evaluate the short-term results of patients undergoing SWL with the Dornier Compact Delta lithotripter for all renal calculi.

Between April 1999 and May 2000, there were 500 renal calculi treated in 166 female and 334 male patients with a mean age of 53 +/- 15 years. All patients who completed treatment were entered in the study and assessed at 1 and 3 months with a plain film of the kidneys, ureters, and bladder. Stone-free rate and final outcome have been evaluated. Final outcome is defined as stone free or residual fragments 4 mm or less. Analysis has been made according to stone size, location, number of treatments per stone, and number of shocks per stone. The analgesia requirements during each treatment and complications have also been analyzed.

The overall stone-free rate for stones <10 mm was 62% at 1 month and 76% at 3 months. For stones 10 to 20 mm, these rates were 53% and 66%, while the rates for stones >20 mm were 41% and 47%, respectively. The final outcome for stones <10 mm was 90% at 1 month and 93% at 3 months, for stones 10 to 20 mm 73% and 84%, and for stones >20 mm 57% and 67%, respectively. The effectiveness quotient for calculi <10 mm was 60%. For calculi 10 to 20 mm, it was 51%, and for those >20 mm, it was 31%. Oral analgesia was given routinely; however, additional intravenous analgesia was necessary in 22% of treatments. No serious complications have been seen.

These results show that with proper patient selection, good results at 1 and 3 months can be achieved with minimal anesthesia during treatment and low retreatment rates. We do not recommend SWL as primary therapy for stones >20 mm.