Shock wave lithotripsy re-treatment rates among 3 different lithotripters - Abstract

Purpose: There is controversy as to whether electromagnetic (EM) lithotripters are associated with higher fragmentation and lower re-treatment rates when compared with electrohydraulic (EH) lithotripters. Therefore, the aim of the present study was to compare SWL re-treatment rates of two EH lithotripters (the Siemens LITHOSTAR and Philips Litho Diagnost M) together with an EM mobile lithotripter (the Storz MODULITH SLX-F2) at a single center.

Methods: A retrospective review of a SWL database was performed for patients with radio-opaque stones between July 2001 and February 2010. A total of 6 434 SWL treatments were included (2 824 with Siemens, 3 136 with Philips, and 474 with Storz). Patients presenting for SWL re-treatment of the same stone were considered SWL failures. Clinical follow-up information was available only for patients treated by the Storz lithotripter.

Results: The Storz lithotripter had a significantly lower re-treatment rate (14.7%) when compared with the Siemens (18.8%, OR = 1.34, p = 0.04) and the Philips (19.6%, OR = 1.41, p = 0.01). However, on multivariate analysis, the Storz significantly differed only from the Philips (OR = 1.36, p = 0.02). When compared with renal pelvic stones, stones in the upper calyx were associated with significantly lower re-treatment rates (OR = 0.65, p = 0.02), whereas distal ureteral stones were associated with significantly higher re-treatment rates (OR = 1.30, p = 0.01). The Storz lithotripter was associated with higher fluoroscopy time (2.4 ± 1.3 min) when compared with the Siemens (1.74 ± 0.8 min) and the Philips (2.13 ± 1.1 min, p = 0.001).

Conclusion: In the present retrospective study, the EM Storz SLX-F2 lithotripter was associated with significantly lower re-treatment rates compared with the Philips EH lithotripter, but not the Siemens.

Mohamed A Elkoushy, Konrad M Szymanski, Douglas D Morehouse, Maurice Anidjar, Sero Andonian

KEYWORDS: Shock wave lithotripsy, lithotripters, re-treatment rate

CORRESPONDENCE: Sero Andonian, MD, MSc, FRCS(C), Assistant Professor of Urology, Royal Victoria Hospital, McGill University Health Centre, 687 Avenue des Pins Ouest, Suite S6.92, Montreal, Quebec, Canada H3A 1A1 ( ).

CITATION: UroToday Int J. 2012 June;5(3):art 18.
doi: http://dx.doi.org/10.3834/uij.1944-5784.2012.06.05