How efficient is extracorporeal shockwave lithotripsy with modern lithotripters for removal of ureteral stones?

Abstract

Purpose: To analyze results of extracorporeal shockwave lithotripsy (SWL) for treatment of ureteral stones with two modern lithotripters.

Patients and methods: A consecutive series of 598 patients with ureteral stones was treated with the Modulith SLX Classic and Modulith SLX-F2 lithotripters. The mean (SD) age of the patients was 54 (17) years, and the mean (SD) stone surface area was 42 (34) mm2. Results were available for 580 patients.

Results: Stone-free ureters were recorded in 563 (97.1%) patients. Stone-free rates were 96.1%, 97.8%, and 97.9%, for the proximal, middle, and distal ureter, respectively. The average number of SWL sessions needed was 1.31. For the proximal, middle, and distal ureter, one SWL session was sufficient in 73.1%, 66.7%, and 83.2% of patients, respectively. Assisting auxiliary procedures were used in 102 patients (18%). The total mean (SD) treatment time was 48 (26) minutes and the mean (SD) number of shockwaves was 3266 (2258). SWL for stones located in the proximal, middle, and distal ureter was carried out in the prone position in 38%, 88%, and 9%, respectively. For 90 patients primarily treated with a large focus, the re-treatment rate was the same as for patients treated with a standard focus. A stone treatment index used to assess the efforts, results, and complications was similar for the two lithotripters and for all stone locations. Thus both lithotripters had similar efficacy.

Conclusion: With consistent use of SWL, a stone-free rate of more than 97% can be attained, with a reasonable re-treatment rate and only modest use of assisting auxiliary procedures.