Comparison of first generation (Dornier HM3) and second generation (Medstone STS) lithotriptors: treatment results with 13,864 renal and ureteral calculi.

Some reports have shown a decreased effectiveness of extracorporeal shock wave lithotripsy (ESWL*) with newer lithotriptors. We used a first generation unmodified Dornier HM3 lithotriptor to treat 5,698 patients with renal and ureteral calculi and a second generation Medstone STS device to treat 8,166 patients with renal and ureteral calculi. The treatment results were compared using the chi-square test to determine statistical significance. The stone-free rate, retreatment rate and post-ESWL secondary procedure rate were 69.5%, 4.4% and 3.1%, respectively, with the Dornier HM3 device and 72.1%, 4.9% and 2.3%, respectively, with the Medstone lithotriptor for single renal stones, and 81.5%, 5.2% and 5.5%, respectively, with the Dornier HM3 and 83.2%, 5.2% and 5.0%, respectively, with the Medstone device for single ureteral stones. There were no statistically significant different results between a second generation tubless Medstone STS lithotriptor and the gold standard unmodified Dornier HM3 instrument.