Safety and Effectiveness of the Ultrasonic Propulsion of Kidney Stones
A feasibility study to test the ability to move kidney stones using a modified ultrasound system. It is the goal of our technology to move the stone fragments to a location within the kidney to improve their chances of passage, and thus reduce the occurrence of additional symptomatic events and retreatment.
|Study Design:||Endpoint Classification: Safety/Efficacy Study
Intervention Model: Single Group Assignment
Masking: Open Label
Primary Purpose: Treatment
|Official Title:||Safety and Effectiveness of the Ultrasonic Propulsion of Kidney Stones|
- Stone movement [ Time Frame: At the time of treatment. To be evaluated with each treatment pulse - where each patient is expected to have an average of 40 pulses delivered over 1 hour ] [ Designated as safety issue: No ]Primary outcome measure is to move a stone a distance greater than 2 mm at the time of device application.
- Sensitivity [ Time Frame: At the time of treatment. To be evaluated with each treatment pulse - where each patient is expected to have an average of 40 pulses delivered over 1 hour ] [ Designated as safety issue: No ]Assess any patient discomfort or feeling at the time of device application. The patient will be asked directly what feeling or discomfort, if any, they experienced with the treatment pulse. The patient will be asked to fill out a pain questionnaire before and after the research study.
- Stone direction [ Time Frame: At the time of treatment. To be evaluated with each treatment pulse - where each patient is expected to have an average of 40 pulses delivered over 1 hour ] [ Designated as safety issue: No ]Test ability to move the stone in a pre-determined direction with device application.
- Stone size [ Time Frame: Established during prescreening ] [ Designated as safety issue: No ]Test the ability to move both large ( > 5 mm) and small ( < 5 mm) stones.
- Device safety [ Time Frame: 90 days ] [ Designated as safety issue: Yes ]Evaluation of adverse events from time of application to the 90 day follow-up.
|Study Start Date:||January 2014|
|Estimated Study Completion Date:||June 2015|
|Estimated Primary Completion Date:||January 2015 (Final data collection date for primary outcome measure)|
Subjects receive treatment with study device.
Device: Propulse 1
Move kidney stones with Propulse 1 device.
Our research group has developed a new, non-invasive technology using low intensity focused ultrasound to reposition kidney stones. This is essentially a conventional diagnostic ultrasound system that is also programmed with longer ultrasounds bursts (50 ms) to impart sufficient energy to physically move a stone. These are similar to pulses that may be used in elastography or acoustic radiation force imaging. Like conventional ultrasound, the probe is placed in contact with the patient's skin to image the stone following standard ultrasound imaging procedure. The same probe is then used to focus the ultrasound and apply a burst (a sequence of pulses) of acoustic force to push the stone. Brightness mode (B-mode) imaging is interleaved with the "pushing" pulses (Push-mode) to monitor stone movement. The Push can be applied to any location and any depth within the image. The user controls the burst amplitude. To control probe surface heating, and thus patient safety, the system is programmed to control when the user is allowed to conduct the next push.
Please refer to this study by its ClinicalTrials.gov identifier: NCT02028559
|United States, Washington|
|University of Washington Department of Urology|
|Seattle, Washington, United States, 98195|
|Principal Investigator:||Jonathan Harper, MD||University of Washington|