Nonsurgical Kidney Stone Removal in Persons with SCI
Abstract
Kidney stones are a significant health problem and are more common than most expect; it is estimated that 1 in every 11 Americans will be diagnosed with kidney stones. The likelihood of forming stones is higher for military Service Members because of operational and environmental factors. The prevalence is four times higher in individuals with spinal cord injury (SCI). Shortly following injury, bones start to demineralize and calcium levels increase in the urine; together with higher levels of bacteria in the urine and infection from bladder catheters, the environment greatly favors the development of kidney stones in the SCI population. Kidney stones in individuals with SCI are different from kidney stones in the general population. The kidney stones in individuals with SCI are more likely to contain bacteria, grow more quickly, are less likely to be passed, and are more likely to regrow after treatment. Less than 10% of kidney stones in the general population are infectious, compared to more than 80% in the SCI population. Furthermore, SCI may dull the sensation of pain caused by kidney stones, so individuals with SCI may develop stones that silently block the kidney and go undiagnosed, leading to loss of kidney function, severe infection, and even death. Because of the high risk of obstruction and infection, it is recommended that individuals with SCI are monitored for stones at least once a year, and that stones larger than 2 mm in size are treated to prevent blockage of the kidney when a stone starts to pass. Treatment of kidney stones requires surgery, most commonly ureteroscopy or shock wave lithotripsy, which can cause health complications for individuals with SCI. Surgery with anesthesia can cause serious respiratory complications and surgery without anesthesia can cause autonomic dysreflexia (AD). Finally, SCI can slow the passage of kidney stones, so any stone fragments left behind after surgery are less likely to pass and can grow again into problematic stones that require more surgery. Our engineers at a Navy lab developed a noninvasive ultrasound technology that can break kidney stones and then reposition the fragments so that they can pass with the urine. The treatment is delivered using a handheld probe that is placed against the patient’s skin, and no anesthesia is needed, so treatment can be done in a clinic setting. We have tested this new technology successfully in awake individuals from the general population, but all of the trials done thus far have not included individuals with SCI, and the technology is currently being commercialized for use in the general population. A urologist who specializes in the care of individuals with SCI and two of her Veteran patients partnered with the Navy lab engineers to propose a new trial that will specifically test the benefits and risks of the new technology in individuals with SCI. We expect that breaking up and repositioning small stones for passage will be particularly helpful for the SCI population, allowing them to avoid surgery and the associated complications and possibly reducing the likelihood that fragments are left behind to regrow. Because this new technology causes minimal discomfort or injury in the general population, we expect that there will be a low risk of it causing AD in individuals with SCI. Overall, the trial will allow us to refine the technology and technique to maximize the benefits for treatment of kidney stones in individuals with SCI. We expect that the new technologies to break and reposition kidney stones will be broadly available for treatment of the general population in 5 years. With successful completion of the proposed trial in individuals with SCI, the technology could be made available to the SCI population at the same time, with the potential to significantly reduce the burden of kidney stones and improve health and quality of life.
Document Details
- Document Type
- DoD Grant Award
- Publication Date
- Jan 04, 2024
- Source ID
- HT94252311081
Entities
People
- Michael Bailey
Organizations
- United States Army
- University of Washington