| Elkoushy MA et al, 2011: Factors Determining Stone-free Rate in Shock Wave Lithotripsy Using Standard Focus of Storz Modulith SLX-F2 Lithotripter |
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Elkoushy MA, Hassan JA, Morehouse DD, Anidjar M, Andonian S Division of Urology, Department of Surgery, McGill University Health Centre, McGill University, Montreal, Quebec, Canada
AbstractAbstractOBJECTIVES: To calculate the efficiency quotient (EQ) of the latest mobile Storz Modulith SLX-F2 lithotripter and to identify the factors determining the stone-free rate. METHODS: A retrospective review of a prospectively collected database of the first consecutive 533 patients undergoing shock wave lithotripsy (SWL) from June 2009 to February 2010 was performed. A total of 16 patients with radiolucent stones and 43 patients with incomplete follow-up were excluded. The patients were followed up with plain radiography to assess the stone-free status. Univariate and multivariate analyses were performed to identify the factors determining the stone-free rates. RESULTS: Follow-up was complete for 474 patients, with a mean age of 54.2 ± 14.5 years. The success rate after a single SWL session was 82.7% (renal 82.2% and ureteral 83.3%; P = .81). The retreatment rate was 14.7% (renal 15.2% and ureteral 14.2%; P = .79). The stone-free rate was 77% (renal 74.1% and ureteral 80.9%; P = .10). Of the 474 patients, 43 had pre-SWL ureteral stents, and 13 required post-SWL ureteral stenting; 35 patients required post-SWL curative procedures. The EQ was 0.66, and the modified EQ was 0.62. On multivariate analysis, the stone-free patients had a smaller stone size (9.5 vs 10.3 mm, P = .02), younger age (53.1 vs 58.0 years, P = .002), right-sided stones (83.6% vs 71.0% P = .001), and the absence of a ureteral stent (78.7% vs 64.3%; P = .001). CONCLUSIONS: The mobile Storz Modulith SLX-F2 lithotripter has an acceptable EQ of 0.66. In the present study, smaller stones (<10 mm), younger age, right-sided stones, and the absence of ureteral stents were associated with significantly greater stone-free rates. Copyright © 2011 Elsevier Inc. All rights reserved. Urology. 2011 Oct;78(4):759-63. doi: 10.1016/j.urology.2011.03.005. Epub 2011 May 7 PMID: 21550641 [PubMed - as supplied by publisher] CommentCommentThe experience of ESWL with the Storz Modulith SLX-F2 lithotripter is reported for 270 patients with renal stones and for 204 with ureteral stones. Only standard focal size was used. The important notations were that absence of an internal stent was associated with a greater stone-free rate. That was also the case for young patients and, as expected, for those with small ( |