PD35-05 HOW DO YOU LIKE YOUR POPCORN? AN EVALUATION OF LASER SETTINGS AND LOCATION IN THE EFFICIENCY OF THE POPCORN EFFECT

Abstract

You have accessJournal of UrologyStone Disease: Surgical Therapy IV1 Apr 2017PD35-05 HOW DO YOU LIKE YOUR POPCORN? AN EVALUATION OF LASER SETTINGS AND LOCATION IN THE EFFICIENCY OF THE POPCORN EFFECT Daniel Wollin, Ruiyang Jiang, Westin Tom, Daniela Radvak, W Neal Simmons, Glenn Preminger, and Michael Lipkin Daniel WollinDaniel Wollin More articles by this author , Ruiyang JiangRuiyang Jiang More articles by this author , Westin TomWestin Tom More articles by this author , Daniela RadvakDaniela Radvak 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.2017.02.1541AboutPDF ToolsAdd to favoritesDownload CitationsTrack CitationsPermissionsReprints ShareFacebookTwitterLinked InEmail INTRODUCTION AND OBJECTIVES There are many techniques for laser lithotripsy of urinary stones. The “popcorn” method involves placing a laser fiber in the center of a collection of stones and firing continuously, allowing fragments to further dust into smaller particles. Our aim was to examine different locations and laser settings on the efficiency of this lithotripsy method. METHODS Pre-fragmented BegoStone phantoms were created between 2-4mm in size to mimic typical popcorning conditions. A 0.5g collection of fragments was placed into two 3D-printed models (a 2 cm spherical calyx model and 4x2 cm ellipsoid pelvis model, Figure 1) and a 200µm laser fiber was positioned at the top of the stones. The laser was fired for 2 minutes with constant irrigation, with 5 trials performed at each setting: 0.2J/50Hz, 0.5J/20Hz, 0.5J/40Hz, 1J/20Hz. The fragmentation efficiency was determined by calculating the mass of stones reduced to sub-2mm particles after 48h of drying. Statistical analysis was performed with ANOVA and Student's T-test. Additionally, high-speed photography was used to examine the mechanism of the popcorn effect. RESULTS The trials within the calyx model were significantly more efficient compared to the pelvis model (0.18g vs 0.13g, p<0.05). When comparing laser settings, there was a difference between groups by one-way ANOVA (F[3,36] = 7.92, p = 0.0003). Post hoc tests showed that 20W settings were significantly more efficient than 0.2J/50Hz (p<0.05) although 0.5J/20Hz was not significantly less efficient than the 20W settings (Figure 2). High-speed imaging shows the majority of fragmentation is due to intermittent stone contact with the laser as opposed to stone-stone interaction. CONCLUSIONS The popcorn effect is most efficient in a smaller space as in the calyx model and as such we recommend displacement of stones into a calyx for popcorning. The 0.5J/20Hz setting produces efficient popcorning at a lower power of 10W, reducing fiber burnback and potential for injury, and is our recommended setting. © 2017FiguresReferencesRelatedDetails Volume 197Issue 4SApril 2017Page: e664 Advertisement Copyright & Permissions© 2017MetricsAuthor Information Daniel Wollin More articles by this author Ruiyang Jiang More articles by this author Westin Tom More articles by this author Daniela Radvak 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 ...