1553 COMPARISON OF TISSUE INJURY FROM A NOVEL TECHNIQUE OF FOCUSED ULTRASONIC PROPULSION OF KIDNEY STONES VERSUS EXTRACORPOREAL SHOCK WAVE LITHOTRIPSY

Abstract

You have accessJournal of UrologyStone Disease: New Technology1 Apr 20131553 COMPARISON OF TISSUE INJURY FROM A NOVEL TECHNIQUE OF FOCUSED ULTRASONIC PROPULSION OF KIDNEY STONES VERSUS EXTRACORPOREAL SHOCK WAVE LITHOTRIPSY Bret Connors, Andrew Evan, Philip Blomgren, Ryan Hsi, Jonathan Harper, Mathew Sorensen, Yak-Nam Wang, Julianna Simon, Marla Paun, Frank Starr, Bryan Cunitz, and Michael Bailey Bret ConnorsBret Connors Indianapolis, IN More articles by this author , Andrew EvanAndrew Evan Indianapolis, IN More articles by this author , Philip BlomgrenPhilip Blomgren Indianapolis, IN More articles by this author , Ryan HsiRyan Hsi Seattle, WA More articles by this author , Jonathan HarperJonathan Harper Seattle, WA More articles by this author , Mathew SorensenMathew Sorensen Seattle, WA More articles by this author , Yak-Nam WangYak-Nam Wang Seattle, WA More articles by this author , Julianna SimonJulianna Simon Seattle, WA More articles by this author , Marla PaunMarla Paun Seattle, WA More articles by this author , Frank StarrFrank Starr Seattle, WA More articles by this author , Bryan CunitzBryan Cunitz Seattle, WA More articles by this author , and Michael BaileyMichael Bailey Seattle, WA More articles by this author View All Author Informationhttps://doi.org/10.1016/j.juro.2013.02.3063AboutPDF ToolsAdd to favoritesDownload CitationsTrack CitationsPermissionsReprints ShareFacebookTwitterLinked InEmail INTRODUCTION AND OBJECTIVES Focused ultrasonic propulsion is a new technique designed to move kidney stones and stone fragments out of the upper urinary collecting system. It is similar to extracorporeal shock wave lithotripsy (SWL) in that both techniques are transcutaneous with acoustic energy originating from an extracorporeal source. However, ultrasonic propulsion generates pulses with substantially lower pressures (20 MPa versus 35-110 MPa), and lower total energy delivered into a kidney for a standard 20-40 min treatment (25-50 J versus 100-200 J) compared to SWL. As such, the injury from ultrasound propulsion would be expected to be lower than SWL. The purpose of this study was to compare the amount of tissue injury produced by focused ultrasound propulsion versus SWL. METHODS Human calcium oxalate monohydrate stones and/or nickel beads were implanted (with ureteroscopy) into 4 kidneys of live pigs (45-55 kg), and repositioned using focused ultrasound propulsion. These kidneys were compared to 12 kidneys treated with an unmodified Dornier HM3 Lithotripter (2400 shocks at 120 SWs/min and 24 kV). After treatment, all kidneys were perfusion-fixed with gluteraldehyde, injected with Microfil, and embedded in paraffin. The kidneys were then serial-sectioned into 10 μm-thick slices, and digital reconstructions were created from photographs of each section. Analysis was performed to assess the volume of tissue injury created by each technique (% functional renal volume, FRV). RESULTS Treatment parameters for the ultrasonic propulsion group averaged 124±30 pulses delivered for a total push burst time of 103±17 seconds per kidney. All stones/beads demonstrated movement. The ultrasonic propulsion technique achieved a 75% clearance rate defined as repositioning of the stone or bead from a calyx into the renal pelvis or ureter. Ultrasonic propulsion produced no detectable lesion compared to 1.08±0.38% FRV for the SWL group. CONCLUSIONS Compared to SWL, focused ultrasonic propulsion produced no detectable tissue injury to the renal parenchyma when using clinical treatment parameters. Efforts are now underway for FDA approval of human feasibility studies of the ultrasonic propulsion technique. © 2013 by American Urological Association Education and Research, Inc.FiguresReferencesRelatedDetails Volume 189Issue 4SApril 2013Page: e637 Peer Review Report Advertisement Copyright & Permissions© 2013 by American Urological Association Education and Research, Inc.MetricsAuthor Information Bret Connors Indianapolis, IN More articles by this author Andrew Evan Indianapolis, IN More articles by this author Philip Blomgren Indianapolis, IN More articles by this author Ryan Hsi Seattle, WA More articles by this author Jonathan Harper Seattle, WA More articles by this author Mathew Sorensen Seattle, WA More articles by this author Yak-Nam Wang Seattle, WA More articles by this author Julianna Simon Seattle, WA More articles by this author Marla Paun Seattle, WA More articles by this author Frank Starr Seattle, WA More articles by this author Bryan Cunitz Seattle, WA More articles by this author Michael Bailey Seattle, WA More articles by this author Expand All Advertisement Advertisement PDF downloadLoading ...