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Intraoperative Assessment of of Burst Wave Lithotripsy (BWL)

The safety and scientific validity of this study is the responsibility of the study sponsor and investigators. Listing a study does not mean it has been evaluated by the U.S. Federal Government. Know the risks and potential benefits of clinical studies and talk to your health care provider before participating. Read our disclaimer for details. Identifier: NCT03873259
Recruitment Status : Not yet recruiting
First Posted : March 13, 2019
Last Update Posted : March 13, 2019
Indiana University
Information provided by (Responsible Party):
Jonathan Harper, University of Washington

Brief Summary:
Burst Wave Lithotripsy (BWL) is a novel method of urinary stone fragmentation that uses multi-cycle bursts of low amplitude ultrasound to induce stone fracture. This is in contrast to traditional extracorporeal shock wave lithotripsy (SWL), which employs a brief single compression/tensile cycle of high amplitude (shock) waves to achieve stone fracture. This is a single-arm feasibility study to test the ability of BWL to comminute (fragment) stones in humans.

Condition or disease Intervention/treatment Phase
Renal Calculi Ureteral Calculi Device: Burst Wave Lithotripsy Not Applicable

Detailed Description:

This is a two-center, single-arm, feasibility study. The two centers are located within the US and include: University of Washington (UW) School of Medicine and Indiana University (IU) Health Urology Clinic.

The investigative study will be performed in the operating room prior to a standard-of-care (SoC) ureteroscopic (URS) laser lithotripsy procedure. The subject will already be under anesthesia. Stones will be limited to ≤7 mm.

The study has one (treatment) arm consisting of 20 subjects. All subjects will be treated with the same output parameters for up to a maximum of 10 minutes per stone. The output parameters are nominally defined as:

  • 350 kHz acoustic frequency
  • 6 MPa maximum peak negative pressure
  • 20 cycle pulse duration
  • 17 Hz pulse repetition frequency

A maximum of 3 stones can be treated per subject.

Safety will be monitored by visual observation of the tissue with an ureteroscopic camera, the self-reported occurrences of adverse events, and occurrences of unplanned emergency department or clinic visits. Fragmentation will be measured by visual observation with an ureteroscopic camera and direct measure of stones removed by basket after the procedure.

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Study Type : Interventional  (Clinical Trial)
Estimated Enrollment : 20 participants
Intervention Model: Single Group Assignment
Masking: None (Open Label)
Masking Description: Outcomes assessors will be blinded to the treatment conditions. This will include review of video data for tissue injury.
Primary Purpose: Treatment
Official Title: Burst Wave Lithotripsy (BWL) for the Comminution of Urinary Tract Stones: Intraoperative Evaluation of Safety and Effectiveness
Estimated Study Start Date : May 1, 2019
Estimated Primary Completion Date : April 30, 2022
Estimated Study Completion Date : April 30, 2022

Resource links provided by the National Library of Medicine

Arm Intervention/treatment
Experimental: Treatment Group
Subjects in this arm receive the 10-minute burst wave lithotripsy intervention dose during their standard-of-care lithotripsy procedure.
Device: Burst Wave Lithotripsy
Fragment upper urinary tract stones

Primary Outcome Measures :
  1. Safety - Area of Tissue Injury [ Time Frame: Day 0 - the day of the experimental procedure immediately following the acoustic procedure. ]
    The primary safety endpoint is the area of hemorrhage observed through direct visualization with the ureteroscope.

  2. Effectiveness - Volume of Fragments < 2 mm [ Time Frame: Day 0 - the day of the experimental procedure immediately following the acoustic procedure. ]
    The primary effectiveness endpoint is the volume fraction of stone fragments less than 2 mm relative to the original stone volume.

Secondary Outcome Measures :
  1. Safety - Adverse Event Assessment [ Time Frame: out to 120 days post-procedure ]
    The secondary safety outcome is the documented occurrence of all adverse events and comparison of the incidence (rate of occurrence) to the adverse events typically associated with shock wave lithotripsy (SWL) and URS

  2. Effectiveness - Time to Full Comminution [ Time Frame: Day 0 - the day of the experimental procedure immediately following the acoustic procedure. ]
    projected time to full comminution defined as the time at which no fragments would be ≤ 2 mm

Information from the National Library of Medicine

Choosing to participate in a study is an important personal decision. Talk with your doctor and family members or friends about deciding to join a study. To learn more about this study, you or your doctor may contact the study research staff using the contacts provided below. For general information, Learn About Clinical Studies.

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Ages Eligible for Study:   18 Years and older   (Adult, Older Adult)
Sexes Eligible for Study:   All
Accepts Healthy Volunteers:   No

Inclusion Criteria:

  • Individuals presenting with at least one kidney stone apparent on CT
  • Individuals scheduled for clinical stone removal via ureteroscopy (URS)
  • Individuals with a stone measured on CT to be ≤ 7 mm in largest dimension.

Exclusion Criteria:

  • Individuals under 18 years of age
  • Individuals belonging to a vulnerable group (pregnant, mentally disabled, prisoner, etc.)
  • Individuals with uncorrected bleeding disorders or coagulopathies
  • Individuals taking a clinically significant anticoagulant dose at the time of the procedure
  • Individuals with a calcified abdominal aortic aneurysm or calcified renal artery aneurysm
  • Individuals with a solitary kidney
  • Individuals with a comorbidity risks which, at the discretion of the physician, would make the patient a poor candidate for the BWL procedure

Information from the National Library of Medicine

To learn more about this study, you or your doctor may contact the study research staff using the contact information provided by the sponsor.

Please refer to this study by its identifier (NCT number): NCT03873259

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Contact: Michael R Bailey, PhD, MS 206-619-2035
Contact: Barbrina Dunmire 206-769-5910

Sponsors and Collaborators
University of Washington
Indiana University
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Principal Investigator: Michael R Bailey, PhD, MS University of Washington

Additional Information:
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Responsible Party: Jonathan Harper, Associate Professor, Department of Urology, University of Washington Identifier: NCT03873259     History of Changes
Other Study ID Numbers: BWL-0001
First Posted: March 13, 2019    Key Record Dates
Last Update Posted: March 13, 2019
Last Verified: March 2019
Individual Participant Data (IPD) Sharing Statement:
Plan to Share IPD: No

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Studies a U.S. FDA-regulated Drug Product: No
Studies a U.S. FDA-regulated Device Product: Yes
Device Product Not Approved or Cleared by U.S. FDA: No
Pediatric Postmarket Surveillance of a Device Product: No
Additional relevant MeSH terms:
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Kidney Calculi
Ureteral Calculi
Pathological Conditions, Anatomical
Kidney Diseases
Urologic Diseases
Urinary Calculi
Ureteral Diseases