Portal de Periódicos da CAPES

1815 COUPLING GEL VISCOSITY - A RELEVANT FACTOR FOR EFFICIENT SHOCK WAVE COUPLING IN SWL

2010; Lippincott Williams & Wilkins; Volume: 183; Issue: 4S Linguagem: Inglês

10.1016/j.juro.2010.02.1740

1527-3792

Thorsten Bergsdorf, C. Chaussy, S. Thueroff,

Kidney Stones and Urolithiasis Treatments

You have accessJournal of UrologyStone Disease: SWL, Ureteroscopic or Percutaneous Stone Removal III1 Apr 20101815 COUPLING GEL VISCOSITY - A RELEVANT FACTOR FOR EFFICIENT SHOCK WAVE COUPLING IN SWL Thorsten Bergsdorf, Christian Chaussy, and Stefan Thueroff Thorsten BergsdorfThorsten Bergsdorf More articles by this author , Christian ChaussyChristian Chaussy More articles by this author , and Stefan ThueroffStefan Thueroff More articles by this author View All Author Informationhttps://doi.org/10.1016/j.juro.2010.02.1740AboutPDF ToolsAdd to favoritesDownload CitationsTrack CitationsPermissionsReprints ShareFacebookTwitterLinked InEmail INTRODUCTION AND OBJECTIVES “Dry head” lithotripters perform shock wave coupling mostly with a coupling bellows and ultrasound gel. Air pockets in the contact area between shock wave system and patient's skin are able to decrease the transfer of shock wave energy considerably and will be a possible factor for poor treatment outcome. Coupling agents with different characteristics (viscosity) were tested in an in vitro setup regarding coupling quality and quantitative influence on stone comminution. METHODS A test tank with integrated transparent membrane for coupling with the shock wave source was installed on a clinical lithotripter (SIEMENS Lithoskop®). For evaluation of the coupling quality (quantity of air bubbles in the contact area) the coupling process was filmed with the use of different ultrasound gels (low, medium and high viscosity, gel disc). In a second setup, artificial stones (AST0118) placed in a mesh with 2 mm were fragmented (60 SW/min., E+12mm: 31 mJ), to assess the quantitative influence of different gel viscosity on disintegration. The number of shock wave pulses, needed for complete fragmentation was the criterion for efficacy. All experiments were performed five times for every coupling agent. RESULTS The quality of coupling was varying over a wide range, whereas the gel disc and gel of low viscosity achieved an air pocket free coupling. Gel with medium and high viscosity in contrast showed a poor coupling quality with multiple bubbles in the coupling area. The disintegration test reflected comparable results (see table). quantitative impact of different gels av. SW-number av. SW-energy gel disk (SIEMENS) 147 4,5J gel with low viscosity (8780 mPas) 168 5,2J gel with medium viscosity (24584 mPas) without manual removal of air bubbles 424 13J with manual removal of air bubbles 168 5,2J gel with high viscosity (40244 mPas) without manual removal of air bubbles 264 8,1J with manual removal of air bubbles 187 5,8J CONCLUSIONS Our in vitro findings indicate, that air pockets within the coupling area deteriorate stone breakage siginificantly. The selection of a proper coupling medium (gel disc or gel with low viscosity) or the accurate removal of air bubbles in the coupling area plays a key role for efficient SWL therapy. Munich, Germany© 2010 by American Urological Association Education and Research, Inc.FiguresReferencesRelatedDetailsCited ByBohris C, Roosen A, Dickmann M, Hocaoglu Y, Sandner S, Bader M, Stief C and Walther S (2018) Monitoring the Coupling of the Lithotripter Therapy Head With Skin During Routine Shock Wave Lithotripsy With a Surveillance CameraJournal of Urology, VOL. 187, NO. 1, (157-163), Online publication date: 1-Jan-2012. Volume 183Issue 4SApril 2010Page: e704 Advertisement Copyright & Permissions© 2010 by American Urological Association Education and Research, Inc.MetricsAuthor Information Thorsten Bergsdorf More articles by this author Christian Chaussy More articles by this author Stefan Thueroff More articles by this author Expand All Advertisement Advertisement PDF DownloadLoading ...