2301 IN-VITRO COMPARISON OF HIGH FREQUENCY VS. LOW FREQUENCY LASER LITHOTRIPSY

Abstract

You have accessJournal of UrologyStone Disease: Basic Research (II)1 Apr 20132301 IN-VITRO COMPARISON OF HIGH FREQUENCY VS. LOW FREQUENCY LASER LITHOTRIPSY Peter Kronenberg and Olivier Traxer Peter KronenbergPeter Kronenberg Amadora, Portugal More articles by this author and Olivier TraxerOlivier Traxer Paris, France More articles by this author View All Author Informationhttps://doi.org/10.1016/j.juro.2013.02.2242AboutPDF ToolsAdd to favoritesDownload CitationsTrack CitationsPermissionsReprints ShareFacebookTwitterLinked InEmail INTRODUCTION AND OBJECTIVES To assess the fragmentation efficiency of laser lithotripsy along a wide range of pulse energies, frequencies, power settings and different laser fibers, paying special attention to compare high frequency to low frequency lithotripsy using a dynamic and innovative testing procedure free from any human interaction bias. METHODS An automated, in saline submerged laser fragmentation testing system was developed, where laser emission took place during a pre-determined period of time (30s) with laser fibers moving at constant velocity over the surface of artificial stones (plaster of Paris) and creating a fissure, whose wide, depth and volume were analyzed. Lithotripter settings included different pulse energies (0.2-1.2J), frequencies (5-40Hz), power levels (4-20W) and laser fiber diameters (200 and 550 μm), including high frequency vs. low frequency experiments maintaining the same total power, totaling 34 different experimental conditions. RESULTS Low frequency with high pulse energy settings showed to be several times (2.1-6.2x) more efficient than high frequency with low pulse energy at the same power level for all levels tested (p<0.00001) and was also associated with deeper (p<0.01) and wider (p<0.00001) fissures. A linear correlation was found between pulse energy and fragmentation volume (p<0.00001), fissure wide (p<0.00001) and fissure depth (p<0.00001). No correlation was found between power (W) used and fragmentation volume (p=0.29), fissure depth (p=0.06) or fissure wide (p=0.7). Large fibers are associated with wider fissures (p<0.00001), small fibers with deeper fissures (p<0.00001), whatever the frequency, pulse energy or total power used. No differences were detected concerning laser fiber diameter and fragmentation volume (p=0.81) except at very low pulse energies (0.2J) were the large fiber was less efficient (p<0.015). CONCLUSIONS At the same total power level, low frequency laser lithotripsy is the most efficient laser lithotripter setting. Elevated power settings using high frequency do not warrant higher fragmentation rates when compared to low frequency high pulse energy settings, even those of several orders of magnitude below. These results emphasize that pulse energy seems to be the key feature in fragmentation efficacy, downplaying both the role of high-frequency and total power setting. © 2013 by American Urological Association Education and Research, Inc.FiguresReferencesRelatedDetails Volume 189Issue 4SApril 2013Page: e943 Advertisement Copyright & Permissions© 2013 by American Urological Association Education and Research, Inc.MetricsAuthor Information Peter Kronenberg Amadora, Portugal More articles by this author Olivier Traxer Paris, France More articles by this author Expand All Advertisement Advertisement PDF downloadLoading ...