MP79-15 THE IMPACT OF LASER PULSE TYPE ON TEMPERATURE CHANGES DURING URETEROSCOPIC LASER LITHOTRIPSY (2019)

You have accessJournal of UrologyStone Disease: Surgical Therapy VI (MP79)1 Apr 2019MP79-15 THE IMPACT OF LASER PULSE TYPE ON TEMPERATURE CHANGES DURING URETEROSCOPIC LASER LITHOTRIPSY Brenton Winship*, Daniel Wollin, Evan Carlos, Chloe Peters, Jingqiu Li, Russell Terry, Kohldon Boydston, Glenn Preminger, and Michael Lipkin Brenton Winship*Brenton Winship* More articles by this author , Daniel WollinDaniel Wollin More articles by this author , Evan CarlosEvan Carlos More articles by this author , Chloe PetersChloe Peters More articles by this author , Jingqiu LiJingqiu Li More articles by this author , Russell TerryRussell Terry More articles by this author , Kohldon BoydstonKohldon Boydston 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/10.1097/01.JU.0000557394.71689.44AboutPDF ToolsAdd to favoritesDownload CitationsTrack CitationsPermissionsReprints ShareFacebookLinked InTwitterEmail Abstract INTRODUCTION AND OBJECTIVES: Moses technology is a Holmium:YAG laser pulse delivery system shown to minimize stone retropulsion. This may allow laser lithotripsy at higher power, however power and heat production are proportional and temperatures over 43C—the threshold for cellular death—may be achieved during ureteroscopic lithotripsy. While prior in vitro studies have shown the importance of irrigation and laser activation time, the impact of laser pulse type on temperature has not been evaluated. METHODS: A flexible ureteroscope was placed in a 36cm, 13Fr ureteral access sheath inserted into a full 250mL bag of saline to simulate a normal caliber ureter, renal pelvis reservoir, and antegrade irrigant flow. A thermocouple was placed adjacent to the tip of a 365µm laser fiber fired for 30 sec at 0.6J/6Hz, 0.8J/8Hz, 1J/10Hz, 1J/20Hz, and 0.2J/80Hz at constant irrigation pressure of 100mmHg. We tested 2 runs per setting at short pulse (500µs), long pulse (1200µs), Moses-contact and Moses-distance. The mean temp change was recorded with 6°C above baseline as a threshold for potential injury (as body temp is 6° below 43°C). RESULTS: The mean temp change from baseline at 0.6J/6Hz remained under 6° and was similar across all pulse types. Long pulse created significantly greater temp increases relative to all pulse types at 0.8J/8Hz and 1J/10Hz. Both Moses settings produced temp changes similar to short pulse at these settings. At 1J/20Hz, long pulse and Moses-contact produced greater temp increases relative to short pulse. At 0.2J/80Hz, all pulse types produced similar temps relative to short pulse, however Moses-contact was significantly warmer than Moses-distance. Long pulse and both Moses settings achieved temp changes over 6° significantly faster than short pulse at 0.8J/8Hz, 1J/10Hz, and 1J/20Hz. At 0.2J/80Hz all pulse types surpassed 6° over baseline at similar rates. (Figure). CONCLUSIONS: Laser pulse type impacts the production of potentially dangerous intraureteral temps during lithotripsy. Long pulse produced the greatest and fastest temp increases. Moses settings produced similar temp increases to short pulse at 0.8J/8Hz and 1J/10Hz, although time to surpass 6° above baseline was similar to long pulse. Both long pulse and Moses have been shown to reduce stone retropulsion. Moses may confer this advantage with decreased heat production. Source of Funding: none Durham, NC; Singapore, Singapore; Durham, NC© 2019 by American Urological Association Education and Research, Inc.FiguresReferencesRelatedDetails Volume 201Issue Supplement 4April 2019Page: e1157-e1157 Advertisement Copyright & Permissions© 2019 by American Urological Association Education and Research, Inc.MetricsAuthor Information Brenton Winship* More articles by this author Daniel Wollin More articles by this author Evan Carlos More articles by this author Chloe Peters More articles by this author Jingqiu Li More articles by this author Russell Terry More articles by this author Kohldon Boydston More articles by this author Glenn Preminger More articles by this author Michael Lipkin More articles by this author Expand All Advertisement PDF downloadLoading ...