PD35-04 DANGEROUS TEMPERATURES CAN BE GENERATED DURING URETEROSCOPIC HOLMIUM LASER LITHOTRIPSY, AN IN VITRO ASSESSMENT

Abstract

You have accessJournal of UrologyStone Disease: Surgical Therapy I1 Apr 2018PD35-04 DANGEROUS TEMPERATURES CAN BE GENERATED DURING URETEROSCOPIC HOLMIUM LASER LITHOTRIPSY, AN IN VITRO ASSESSMENT Daniel Wollin, Evan Carlos, Brenton Winship, Westin Tom, W. Neal Simmons, Glenn Preminger, and Michael Lipkin Daniel WollinDaniel Wollin More articles by this author , Evan CarlosEvan Carlos More articles by this author , Brenton WinshipBrenton Winship More articles by this author , Westin TomWestin Tom More articles by this author , W. Neal SimmonsW. Neal Simmons More articles by this author , Glenn PremingerGlenn Preminger More articles by this author , and Michael LipkinMichael Lipkin More articles by this author View All Author Informationhttps://doi.org/10.1016/j.juro.2018.02.1715AboutPDF ToolsAdd to favoritesDownload CitationsTrack CitationsPermissionsReprints ShareFacebookTwitterLinked InEmail INTRODUCTION AND OBJECTIVES Ureteroscopic laser lithotripsy requires irrigation for adequate visualization and temperature control during treatment of ureteral stones. However, there is little data on how different irrigation and laser settings affect the ureteral wall and surrounding tissues. This becomes especially important given that exponential thermal cytotoxicity has been shown at temperatures over 43°C. We evaluated the effect of laser settings and irrigation flow on ureteral temperature in an in vitro setting. METHODS To mimic ureteroscopic laser lithotripsy, we simulated clinically relevant irrigation flow rates and fired a holmium laser within saline irrigation tubing. The probe tip of a thermometer was placed 1mm from the tip of a 200μm laser fiber, which was fired for 60 seconds at 0.2J/50Hz, 0.6J/6Hz, 0.8J/8Hz, 1J/10Hz and 1J/20Hz at specified room-temperature flow rates (100cc/min, 50cc/min, 0cc/min). We recorded temperatures every 5 seconds. The overall maximum temperature was noted and each laser/flow trial was duplicated. Maximum temperatures for each trial were compared using ANOVA across irrigation settings. RESULTS At 100cc/min, only the 1J/20Hz laser setting produced a statistically significant higher maximum temperature (p < 0.01), although this was not clinically significant (Tmax 30.7°C). At a lower irrigation rate of 50cc/min, the 1J/20Hz setting was again the only significantly higher maximum temperature (p < 0.05) with a Tmax of 43.4°C. With no flow, all maximum temperatures reached over 43°C, with 0.8J/8Hz, 1J/10Hz, and 1J/20Hz each statistically higher than the lower-energy settings (p < 0.05). 43°C was achieved within 15 seconds of laser firing at the 1J/20Hz, 1J/10Hz, 0.8J/8Hz, and 0.6J/6Hz settings. Additionally, with no irrigation 1J/20Hz eclipsed 43°C within 5 seconds and reached ≥100°C causing us to halt its trials 10 seconds early (Figure). CONCLUSIONS Despite increasing laser power settings, adequate irrigation can maintain relatively stable temperatures within an in vitro ureteral system. As irrigation rates decrease, even lower laser power settings achieve potential harmful temperatures in a matter of seconds. © 2018FiguresReferencesRelatedDetails Volume 199Issue 4SApril 2018Page: e722 Advertisement Copyright & Permissions© 2018MetricsAuthor Information Daniel Wollin More articles by this author Evan Carlos More articles by this author Brenton Winship More articles by this author Westin Tom More articles by this author W. Neal Simmons More articles by this author Glenn Preminger More articles by this author Michael Lipkin More articles by this author Expand All Advertisement Advertisement PDF downloadLoading ...