LBA01-16 COMPARATIVE ANALYSES AND ABLATION EFFICACY OF THULIUM FIBER LASER BY STONE COMPOSITION

Abstract

You have accessJournal of UrologyCME1 Apr 2023LBA01-16 COMPARATIVE ANALYSES AND ABLATION EFFICACY OF THULIUM FIBER LASER BY STONE COMPOSITION Jeffrey Johnson, Miyad Movassaghi, David Han, Srinath-Reddi Pingle, Justin Lee, Prakash Gorroochurn, James Williams, Michael Schulster, and Ojas Shah Jeffrey JohnsonJeffrey Johnson More articles by this author , Miyad MovassaghiMiyad Movassaghi More articles by this author , David HanDavid Han More articles by this author , Srinath-Reddi PingleSrinath-Reddi Pingle More articles by this author , Justin LeeJustin Lee More articles by this author , Prakash GorroochurnPrakash Gorroochurn More articles by this author , James WilliamsJames Williams More articles by this author , Michael SchulsterMichael Schulster More articles by this author , and Ojas ShahOjas Shah More articles by this author View All Author Informationhttps://doi.org/10.1097/JU.0000000000003360.16AboutPDF ToolsAdd to favoritesDownload CitationsTrack CitationsPermissionsReprints ShareFacebookLinked InTwitterEmail Abstract INTRODUCTION AND OBJECTIVE: There is limited data on the ablation settings and photothermal effects of thulium fiber laser (TFL) lithotripsy across various stone compositions. We aim to identify settings by stone type that optimize efficiency and avoid undesirable effects (i.e. charring) during TFL lithotripsy. METHODS: Specimens of calcium oxalate monohydrate, calcium oxalate dihydrate, uric acid, struvite, cystine, carbonate apatite and brushite stones were ablated to ≤1mm residual fragments using 13 settings with the Coloplast© TFL Drive. Pre-ablation mass, post-ablation mass, ablation time and total energy were recorded. Samples were analyzed using FTIR spectroscopy and electron microscopy. RESULTS: Pulse duration impacted ablation effectiveness greatly with 75% of inadequate ablations occurring in medium or long pulse settings. Calcium oxalate dihydrate, cystine, and struvite ablated most efficiently with 0.2J×100Hz, short pulse. Calcium oxalate monohydrate ablated most efficiently with 0.4J×40Hz, short pulse. The average percent of mass lost during ablation was 57%; cystine averaged the highest at 71%. Charring was seen in 40% of stones, mostly in uric acid, cystine, and brushite stones. Electron microscopy of char demonstrated a porous melting effect. FTIR spectroscopy of brushite char demonstrated a chemical composition change to amorphous calcium phosphate. CONCLUSIONS: Our trial is the first in vitro trial on stone ablation efficacy by stone composition. Across all settings and stone types 0.05J×1000Hz was the most effective ablation setting, however this is above our clinically recommended power of <=20 W. When operating in the kidney and using clinically acceptable TFL settings to minimize the risk of thermal injury, we recommend starting with short pulse 0.2J×100Hz and 0.4J×40Hz to cover most stone types, and adjusting the settings based on visual ablation effects intraoperatively and the clinical scenario (e.g. limited irrigation flow, narrow infundibulum). Further investigation is needed to continue to optimize TFL stone treatment settings. Source of Funding: Coloplast © 2023 by American Urological Association Education and Research, Inc.FiguresReferencesRelatedDetails Volume 209Issue Supplement 4April 2023Page: e1183 Advertisement Copyright & Permissions© 2023 by American Urological Association Education and Research, Inc.MetricsAuthor Information Jeffrey Johnson More articles by this author Miyad Movassaghi More articles by this author David Han More articles by this author Srinath-Reddi Pingle More articles by this author Justin Lee More articles by this author Prakash Gorroochurn More articles by this author James Williams More articles by this author Michael Schulster More articles by this author Ojas Shah More articles by this author Expand All Advertisement PDF downloadLoading ...