Pd28-04 advanced burst wave lithotripsy for human trials

You have accessJournal of UrologyCME1 Apr 2023PD28-04 ADVANCED BURST WAVE LITHOTRIPSY FOR HUMAN TRIALS Arturo Holmes, Ekaterina Kuznetsova, Shivani Ramesh, Adam D. Maxwell, Ga Won Kim, John Kucewicz, Bryan W. Cunitz, Wayne Kreider, Barbrina Dunmire, Michael R. Bailey, Mathew D. Sorensen, and Jonathan D. Harper Arturo HolmesArturo Holmes More articles by this author , Ekaterina KuznetsovaEkaterina Kuznetsova More articles by this author , Shivani RameshShivani Ramesh More articles by this author , Adam D. MaxwellAdam D. Maxwell More articles by this author , Ga Won KimGa Won Kim More articles by this author , John KucewiczJohn Kucewicz More articles by this author , Bryan W. CunitzBryan W. Cunitz More articles by this author , Wayne KreiderWayne Kreider More articles by this author , Barbrina DunmireBarbrina Dunmire More articles by this author , Michael R. BaileyMichael R. Bailey More articles by this author , Mathew D. SorensenMathew D. Sorensen More articles by this author , and Jonathan D. HarperJonathan D. Harper More articles by this author View All Author Informationhttps://doi.org/10.1097/JU.0000000000003313.04AboutPDF ToolsAdd to favoritesDownload CitationsTrack CitationsPermissionsReprints ShareFacebookLinked InTwitterEmail Abstract INTRODUCTION AND OBJECTIVE: The first in human trials of burst wave lithotripsy (BWL) demonstrated consistent fragmentation of upper tract stones with no or mild hematuria. However, for a randomized, controlled trial of treating 2-7 mm stones we wanted improved image resolution to not miss any fragments and ability to break stones to<1 mm at skin to stone depths of 4-10 cm on ultrasound. The system was redesigned and tested to add these improvements. METHODS: A new ultrasound platform for imaging, ultrasonic propulsion, and BWL was designed and constructed (‘Propulse2’). The imaging employed high-bandwidth phased array probes and Verasonics Vantage imaging engine. Resolution changes were compared against existing devices in a standard imaging phantom. Longer focus therapy transducers were designed. Additionally, the transducers operate at frequencies between 350-800 kHz. A high-power pulse generator was developed to achieve pressure at greater depths, produce longer duration pulses, and enable interleaving BWL with ultrasonic propulsion pulses and accelerate fragmentation. To test the therapeutic capabilities, rehydrated 2-7 mm calcium oxalate monohydrate stones were sonicated with each transducer and frequency in a calyx phantom in 2.5-minute intervals for 20 minutes. After each interval, the fragments were weighed and sieved to 1 and 2 mm, then returned to the phantom. Burst cycle durations between 5 to 160 cycles were tested with and without interleaved pulses and depths 4-10 cm all at focal peak negative pressures of 7 MPa. RESULTS: Imaging contrast (signal to noise ratio) with the old and new systems was 1.62 and 3.45 at 6 cm depth and 1.07 and 1.75 at 10 cm depth. Lateral resolution was improved by a factor of 2.1 at 6 cm and 2.5 at 10 cm. Targeting accuracy was measured to be within 1 mm for all transducers. On average for all stones and conditions, 81% and 75% of the stone mass was comminuted to<2 mm and < 1mm fragments respectively in 20 minutes (Figure 1A). Subanalysis of fragmentation to<2 mm fragments showed fewer than 20 cycles were less effective even with increased pulse repetition rate to equalize energy (Figure 1B). CONCLUSIONS: The system demonstrated over twice the imaging contrast and resolution and capability to fragment stones more finely over a 4-10 cm depth. Propulse2 has been approved for human trials (ClinicalTrials.gov number, NCT04796792). Source of Funding: Work supported by NIDDK P01 DK043881. © 2023 by American Urological Association Education and Research, Inc.FiguresReferencesRelatedDetails Volume 209Issue Supplement 4April 2023Page: e819 Advertisement Copyright & Permissions© 2023 by American Urological Association Education and Research, Inc.MetricsAuthor Information Arturo Holmes More articles by this author Ekaterina Kuznetsova More articles by this author Shivani Ramesh More articles by this author Adam D. Maxwell More articles by this author Ga Won Kim More articles by this author John Kucewicz More articles by this author Bryan W. Cunitz More articles by this author Wayne Kreider More articles by this author Barbrina Dunmire More articles by this author Michael R. Bailey More articles by this author Mathew D. Sorensen More articles by this author Jonathan D. Harper More articles by this author Expand All Advertisement PDF downloadLoading ...