2110 STONE FRAGMENTATION USING A NEW ACOUSTIC LENS DESIGN FOR ELECTROMAGNETIC SHOCKWAVE LITHOTRIPTERS IN A SWINE MODEL (2010)

You have accessJournal of UrologyStone Disease: New Technology1 Apr 20102110 STONE FRAGMENTATION USING A NEW ACOUSTIC LENS DESIGN FOR ELECTROMAGNETIC SHOCKWAVE LITHOTRIPTERS IN A SWINE MODEL John Mancini, Walter Simmons, Eliza Raymundo, Daniel Yong, Michael Ferrandino, Michael Lipkin, Dorit Zilberman, Pei Zhong, and Glenn Preminger John ManciniJohn Mancini More articles by this author , Walter SimmonsWalter Simmons More articles by this author , Eliza RaymundoEliza Raymundo More articles by this author , Daniel YongDaniel Yong More articles by this author , Michael FerrandinoMichael Ferrandino More articles by this author , Michael LipkinMichael Lipkin More articles by this author , Dorit ZilbermanDorit Zilberman More articles by this author , Pei ZhongPei Zhong More articles by this author , and Glenn PremingerGlenn Preminger More articles by this author View All Author Informationhttps://doi.org/10.1016/j.juro.2010.02.2197AboutPDF ToolsAdd to favoritesDownload CitationsTrack CitationsPermissionsReprints ShareFacebookTwitterLinked InEmail INTRODUCTION AND OBJECTIVES Recent studies suggest that third generation electromagnetic (EM) shock wave lithotripters produce reduced stone fragmentation and may be less clinically effective than earlier generation electohydraulic (EH) lithotripters. A new acoustic lens for a third generation electromagnetic lithotripter (Siemens Modularis) has been developed to produce an idealized pressure waveform with a low peak pressure and broad focal zone, that more closely mimics the profile of earlier-generation EH lithotripters. Herein, we report the stone fragmentation capabilities of this newly designed acoustic lens in an in vivo model. METHODS Seventeen juvenile female farm swine weighing approximately 36kg were used to compare the fragmentation of surgically implanted BegoStone phantoms using modified and original lenses in a Siemens Modularis lithotripter after 500 and 2000 shocks. After shock wave lithotripsy, the animals were euthanized and bilateral nephrectomies were performed. The kidneys were grossly inspected, then bi-valved for assessment of fragmentation pattern and collection of stone fragments. Fragments were filtered through a stack of standard sieves with decreasing mesh size of 4, 2.8, 2, and 1 mm, respectively. Fragmentation efficiency was measured by the percentage of fragments (by weight) that were less than 2 mm. The kidneys were also assessed for volume of parenchymal damage. RESULTS A total of 34 renal units were used to evaluate the fragmentation efficiency of the modified lens compared to the original lens using BegoStone phantoms. After 500 shocks the fragmentation efficiency for the modified and original electromagnetic lenses were 51.9 ± 16.7% and 48.0 ± 12.1% (p=0.5991), respectively. However, after 2000 shocks, the modified lens showed improved stone fragmentation at 83.3 ± 8.5%, compared to 63.4 ± 17.4% for the original lens (p=0.0099). There was no evidence of renal injury, including subcapsular hematoma on gross evaluation. CONCLUSIONS The new acoustic lens designed for this third generation electromagnetic lithotripter, which produces a broader focal zone and idealized pressure curve, produces significantly improved stone fragmentation in an in vivo model, without evidence of increased renal injury. This new technology could potentially be retrofitted to existing EM lithotripters, thereby improving the clinical effectiveness of electromagnetic lithotripsy devices. Durham, NC© 2010 by American Urological Association Education and Research, Inc.FiguresReferencesRelatedDetails Volume 183Issue 4SApril 2010Page: e820 Advertisement Copyright & Permissions© 2010 by American Urological Association Education and Research, Inc.MetricsAuthor Information John Mancini More articles by this author Walter Simmons More articles by this author Eliza Raymundo More articles by this author Daniel Yong More articles by this author Michael Ferrandino More articles by this author Michael Lipkin More articles by this author Dorit Zilberman More articles by this author Pei Zhong More articles by this author Glenn Preminger More articles by this author Expand All Advertisement Advertisement PDF downloadLoading ...