Browsing by Author "Metzler, Ian S."

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    First Series Using Ultrasonic Propulsion and Burst Wave Lithotripsy to Treat Ureteral Stones
    (American Urological Association Education and Research, Inc., 2022) Hall, M. Kennedy; Thiel, Jeff; Dunmire, Barbrina; Samson, Patrick C.; Kessler, Ross; Sunaryo, Peter; Sweet, Robert M.; Metzler, Ian S.; Chang, Helena C.; Gunn, Martin; Dighe, Manjiri; Anderson, Layla; Popchoi, Christina; Managuli, Ravi; Cunitz, Bryan W.; Burke, Barbara H.; Ding, Lisa; Gutierrez, Brianna; Liu, Ziyue; Sorensen, Mathew D.; Wessells, Hunter; Bailey, Michael R.; Harper, Jonathan D.; Biostatistics and Health Data Science, School of Medicine
    Purpose: Our goal was to test transcutaneous focused ultrasound in the form of ultrasonic propulsion and burst wave lithotripsy to reposition ureteral stones and facilitate passage in awake subjects. Materials and methods: Adult subjects with a diagnosed proximal or distal ureteral stone were prospectively recruited. Ultrasonic propulsion alone or with burst wave lithotripsy was administered by a handheld transducer to awake, unanesthetized subjects. Efficacy outcomes included stone motion, stone passage, and pain relief. Safety outcome was the reporting of associated anticipated or adverse events. Results: Twenty-nine subjects received either ultrasonic propulsion alone (n = 16) or with burst wave lithotripsy bursts (n = 13), and stone motion was observed in 19 (66%). The stone passed in 18 (86%) of the 21 distal ureteral stone cases with at least 2 weeks follow-up in an average of 3.9±4.9 days post-procedure. Fragmentation was observed in 7 of the burst wave lithotripsy cases. All subjects tolerated the procedure with average pain scores (0-10) dropping from 2.1±2.3 to 1.6±2.0 (P = .03). Anticipated events were limited to hematuria on initial urination post-procedure and mild pain. In total, 7 subjects had associated discomfort with only 2.2% (18 of 820) propulsion bursts. Conclusions: This study supports the efficacy and safety of using ultrasonic propulsion and burst wave lithotripsy in awake subjects to reposition and break ureteral stones to relieve pain and facilitate passage.
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    Fragmentation of Stones by Burst Wave Lithotripsy in the First 19 Humans
    (Wolters Kluwer, 2022) Harper, Jonathan D.; Lingeman, James E.; Sweet, Robert M.; Metzler, Ian S.; Sunaryo, Peter L.; Williams, James C., Jr.; Maxwell, Adam D.; Thiel, Jeff; Cunitz, Bryan W.; Dunmire, Barbrina; Bailey, Michael R.; Sorensen, Mathew D.; Urology, School of Medicine
    Purpose: We report stone comminution in the first 19 human subjects by burst wave lithotripsy (BWL), which is the transcutaneous application of focused, cyclic ultrasound pulses. Materials and methods: This was a prospective multi-institutional feasibility study recruiting subjects undergoing clinical ureteroscopy (URS) for at least 1 stone ≤12 mm as measured on computerized tomography. During the planned URS, either before or after ureteroscope insertion, BWL was administered with a handheld transducer, and any stone fragmentation and tissue injury were observed. Up to 3 stones per subject were targeted, each for a maximum of 10 minutes. The primary effectiveness outcome was the volume percent comminution of the stone into fragments ≤2 mm. The primary safety outcome was the independent, blinded visual scoring of tissue injury from the URS video. Results: Overall, median stone comminution was 90% (IQR 20, 100) of stone volume with 21 of 23 (91%) stones fragmented. Complete fragmentation (all fragments ≤2 mm) within 10 minutes of BWL occurred in 9 of 23 stones (39%). Of the 6 least comminuted stones, likely causative factors for decreased effectiveness included stones that were larger than the BWL beamwidth, smaller than the BWL wavelength or the introduction of air bubbles from the ureteroscope. Mild reddening of the papilla and hematuria emanating from the papilla were observed ureteroscopically. Conclusions: The first study of BWL in human subjects resulted in a median of 90% comminution of the total stone volume into fragments ≤2 mm within 10 minutes of BWL exposure with only mild tissue injury.