MP10-10 A NOVEL URINARY STONE MODEL - COMPACTED COM - FOR LITHOTRIPSY RESEARCH

Field: Medicine (Health Sciences)

You have accessJournal of UrologyStone Disease: Basic Research & Pathophysiology II (MP10)1 Apr 2020MP10-10 A NOVEL URINARY STONE MODEL - COMPACTED COM - FOR LITHOTRIPSY RESEARCH Tony T. Chen*, Adam D. Maxwell, Elizabeth Lynch, Christopher Hunter, Valentina Valero, James C. Williams, Anthony Gardner, Michael R. Bailey, and Mathew D. Sorensen Tony T. Chen*Tony T. Chen* More articles by this author , Adam D. MaxwellAdam D. Maxwell More articles by this author , Elizabeth LynchElizabeth Lynch More articles by this author , Christopher HunterChristopher Hunter More articles by this author , Valentina ValeroValentina Valero More articles by this author , James C. WilliamsJames C. Williams More articles by this author , Anthony GardnerAnthony Gardner More articles by this author , Michael R. BaileyMichael R. Bailey More articles by this author , and Mathew D. SorensenMathew D. Sorensen More articles by this author View All Author Informationhttps://doi.org/10.1097/JU.0000000000000830.010AboutPDF ToolsAdd to favoritesDownload CitationsTrack CitationsPermissionsReprints ShareFacebookLinked InTwitterEmail Abstract INTRODUCTION AND OBJECTIVE: Artificial stone models are used in lithotripsy research. While the value of models is their availability and reproducibility in shape and characteristics, a challenge remains in replicating the fragmentation characteristics of human stones for the lithotripter technology of interest. Here, we describe a novel artificial stone model that closely mimics fragmentation of human calcium oxalate monohydrate stones (COM) by burst wave lithotripsy (BWL). We hypothesized that a stone model that more closely mimics the constituents of human stones will behave and fracture more like a human stone. METHODS: COM, albumin (bovine), and water, were mixed and compressed inside a cylindrical stone mold using a benchtop hydraulic press. Two mixtures were tested at 3 pressures. The stones were incubated for 12 hours at 100oC to denature the protein and were then hydrated for 48 hours. The artificial stones were shaped with a scalpel to pair to individual 4.5-5 mm human stones (308-650 mg) to address variability in human stone mass and size. The BWL system was used to fragment the stones in a kidney phantom in a tank filled with degassed, deionized water. Exposure consisted of 20-cycle bursts at 350 kHz frequency, 7 MPa peak negative pressure, and 10 Hz pulse repetition rate. Treatment lasted for 45 minutes or until all fragments passed through a 2-mm sieve assessed at 5-minute increments. The maximum dimension of the fragments passed through the sieve were then measured. RESULTS: Human COM stones fragmented at a rate of 7.6 ± 3.8% per minute and all dimensions of all fragments were smaller than 2 mm. Three stone mixtures produced nearly identical mass fragmentation rates (Table 1). In addition, all dimensions of fragments were smaller than 2 mm in 88% of the mix 1 stones made at 68 MPa. Stones made with greater pressure were harder to fragment. CONCLUSIONS: A model stone - Compacted COM - fragmented at a similar rate to human COM stones and produced a similar fragment size distribution with BWL in conditions simulating those in vivo. The stones were made by pressure and heat in a 12-hour process. Although not tested here, different shape of stone mold are possible, and multiple stones can be made at once in one mold. This novel prototype provides a tool to potentially refine and validate BWL and other lithotripsy technologies and techniques. Source of Funding: The work was supported by NIDDK P01-DK043881 and K01-DK104854. © 2020 by American Urological Association Education and Research, Inc.FiguresReferencesRelatedDetails Volume 203Issue Supplement 4April 2020Page: e129-e129 Advertisement Copyright & Permissions© 2020 by American Urological Association Education and Research, Inc.MetricsAuthor Information Tony T. Chen* More articles by this author Adam D. Maxwell More articles by this author Elizabeth Lynch More articles by this author Christopher Hunter More articles by this author Valentina Valero More articles by this author James C. Williams More articles by this author Anthony Gardner More articles by this author Michael R. Bailey More articles by this author Mathew D. Sorensen More articles by this author Expand All Advertisement PDF downloadLoading ...