Ten percent of the U.S. population will develop kidney stones. Three million Americans seek treatment each year, and total treatment cost is over $2B. Initial success rates range from ~70% to greater than 90% depending on the type of treatment performed, but stones will recur in half the patients within 5 years. Follow- up surgical management of stones is complex and individualized but expends significant resources, creates additional discomfort and can expose the patient to X-rays many times. Small stone fragments in the renal pelvis have a good chance of passing naturally, but fragments located in the lower calyces are more likely to remain and become problematic. We have developed a handheld pulsed-ultrasound device to non-invasively expel stone fragments (or small stones) from the kidney. We have also developed a unique ultrasound imaging method to dramatically enhance the visualization of kidney stones, which provides a safe alternative to the ionizing radiation of plane X-ray and computerized tomography (CT). A prototype device has been engineered from a commercially available diagnostic ultrasound imager and probe. Preliminary results in animal models show we can localize and safely repositioning stones from the lower calyx to the ureteropelvic juncture (UPJ) in less than 5 minutes, a procedure that could easily be completed during an office visit. The objective of this proposal using human subjects is to assess the ability of this device to reposition stone fragments. We will first measure, imaging accuracy of enhanced ultrasound localization compared to CT as the gold standard. In partnership with a regulatory consultant, we will prepare an application to the U.S. Food and Drug Administration (FDA) for an Investigational Device Exemption (IDE) to test the therapeutic strategy of repositioning stones in human subjects. The long-term goal is to provide urologists with a new non-invasive surgical option to clear stone fragments and small stones from the kidney. This device would be used to clear residual fragments remaining after shock wave lithotripsy (or invasive stone removal such as ureteroscopy), and could be a means to prophylactically expel small stones from the kidney before they become symptomatic. This stone repositioning device and its complementary stone imaging methodology have the potential to deliver safer, more effective treatments and significantly lower healthcare costs.

Public Health Relevance

The proposal is to transition technology to detect and reposition kidney stones with ultrasound to facilitate stone clearance. As such kidney stone patients who account for 10% of the US population might be spared ionizing radiation of stone detection by x-ray computerized tomography and spared surgery or lithotripsy for initial or follow-on treatment.

Agency
National Institute of Health (NIH)
Institute
National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK)
Type
Research Project (R01)
Project #
5R01DK092197-02
Application #
8284330
Study Section
Urologic and Kidney Development and Genitourinary Diseases Study Section (UKGD)
Program Officer
Kirkali, Ziya
Project Start
2011-07-01
Project End
2014-04-30
Budget Start
2012-05-01
Budget End
2013-04-30
Support Year
2
Fiscal Year
2012
Total Cost
$514,450
Indirect Cost
$152,304
Name
University of Washington
Department
Physics
Type
Schools of Earth Sciences/Natur
DUNS #
605799469
City
Seattle
State
WA
Country
United States
Zip Code
98195
Harper, Jonathan D; Dunmire, Barbrina; Wang, Yak-Nam et al. (2014) Preclinical safety and effectiveness studies of ultrasonic propulsion of kidney stones. Urology 84:484-9
Connors, Bret A; Evan, Andrew P; Blomgren, Philip M et al. (2014) Comparison of tissue injury from focused ultrasonic propulsion of kidney stones versus extracorporeal shock wave lithotripsy. J Urol 191:235-41
Hsi, Ryan S; Dunmire, Barbrina; Cunitz, Bryan W et al. (2014) Content and face validation of a curriculum for ultrasonic propulsion of calculi in a human renal model. J Endourol 28:459-63
Harper, Jonathan D; Sorensen, Mathew D; Cunitz, Bryan W et al. (2013) Focused ultrasound to expel calculi from the kidney: safety and efficacy of a clinical prototype device. J Urol 190:1090-5
Lu, Wei; Sapozhnikov, Oleg A; Bailey, Michael R et al. (2013) Evidence for trapped surface bubbles as the cause for the twinkling artifact in ultrasound imaging. Ultrasound Med Biol 39:1026-38
Sorensen, Mathew D; Harper, Jonathan D; Hsi, Ryan S et al. (2013) B-mode ultrasound versus color Doppler twinkling artifact in detecting kidney stones. J Endourol 27:149-53
Sorensen, Mathew D; Bailey, Michael R; Hsi, Ryan S et al. (2013) Focused ultrasonic propulsion of kidney stones: review and update of preclinical technology. J Endourol 27:1183-6
Sapozhnikov, Oleg A; Bailey, Michael R (2013) Radiation force of an arbitrary acoustic beam on an elastic sphere in a fluid. J Acoust Soc Am 133:661-76
Shah, Anup; Harper, Jonathan D; Cunitz, Bryan W et al. (2012) Focused ultrasound to expel calculi from the kidney. J Urol 187:739-43