Mp43-15 in-Vitro Comparison of a Novel Recessed Tip Versus Standard Tip Fiber for Stone Dusting With Thulium Fiber Laser

You have accessJournal of UrologySurgical Technology & Simulation: Instrumentation & Technology II (MP43)1 May 2024MP43-15 IN-VITRO COMPARISON OF A NOVEL RECESSED TIP VERSUS STANDARD TIP FIBER FOR STONE DUSTING WITH THULIUM FIBER LASER Cyrus Chehroudi, Louisa Ho, Fabrice Henry, and Sri Sivalingam Cyrus ChehroudiCyrus Chehroudi , Louisa HoLouisa Ho , Fabrice HenryFabrice Henry , and Sri SivalingamSri Sivalingam View All Author Informationhttps://doi.org/10.1097/01.JU.0001008720.96896.83.15AboutPDF ToolsAdd to favoritesDownload CitationsTrack CitationsPermissionsReprints ShareFacebookLinked InTwitterEmail Abstract INTRODUCTION AND OBJECTIVE: Intraoperative laser fiber degradation and carbonization (charring) of stone impairs lithotripsy efficiency. Recessed tip (RT) laser fibers prevent fiber degradation by shielding the fiber from the target. While commonly utilized in holmium lithotripsy, there is limited data for its application in thulium fiber laser (TFL). We developed a bench-top model to compare the efficiency of stone dusting and fiber tip degradation in TFL with a standard bare tip (BT) versus a novel RT fiber. METHODS: Canine stones (100% calcium oxalate monohydrate) of similar size were placed in a saline-filled ureteroscopy model, with a clear tube set at a 40° angle, and 1 mm mesh filter placed at the end (see figure). Continuous flow irrigation was maintained in the system. A single Urologist used a flexible ureteroscope and FiberDust TFL system with 200 μm BT (n=5) and RT fibers (n=5) to completely dust each stone at settings of 0.3 J/100 Hz and short pulse width. Residual fragments>1 mm were removed and weighed, and stone dusting efficiency was calculated . Each fiber tip was measured prior to and after five minutes of lithotripsy using a microscope to assess fiber tip burn-back. RESULTS: RT fibers experienced almost no burn-back at the end of each 5-minute trial (0.20±0.11 mm), with significantly less relative burn-back compared to BT fibers (1.6±0.89% vs. 17.5±18.4%, p=.01). However, only 3 of 5 RT fibers were able to completely dust the stone, and all trials left detectable stone fragments, with a mean residual stone weight of 8.9±0.02%. In comparison, the stone was fully dusted in all 5 BT fiber trials (mean 2.70±1.30 min), with no detectable residual fragments. There was a trend towards improved dusting efficiency using BT fibers compared to RT fibers (0.19±0.06 vs. 0.12±0.09 mg/s, p=.16). CONCLUSIONS: RT fibers almost completely eliminate tip degradation in vitro, at the expense of higher residual stone volume and possibly less dusting efficiency. Further studies may help determine an ideal degree of laser tip recession to balance burn-back with lithotripsy efficiency. Download PPT Source of Funding: None © 2024 by American Urological Association Education and Research, Inc.FiguresReferencesRelatedDetails Volume 211Issue 5SMay 2024Page: e699 Advertisement Copyright & Permissions© 2024 by American Urological Association Education and Research, Inc.Metrics Author Information Cyrus Chehroudi More articles by this author Louisa Ho More articles by this author Fabrice Henry More articles by this author Sri Sivalingam More articles by this author Expand All Advertisement PDF downloadLoading ...