Researchers have made a groundbreaking discovery in the field of brain blood clot clearance with the development of a new tool and technique utilizing vortex ultrasound. The revolutionary approach uses ultrasonic waves in the form of a “tornado” to effectively break down clots in the brain. In early stage tests, the method proved to be faster in eliminating clots in a simulated model of cerebral venous sinus thrombosis (CVST) compared to existing techniques.
Cerebral venous sinus thrombosis (CVST) is a pathological condition in which blood clots form in the cerebral venous sinuses, leading to strokes in young individuals. According to European research, the incidence of CVST ranges from 2 to 13 cases per million per year. In the United States, the incidence of CVST has been growing. Early diagnosis and anticoagulant therapy have been shown to minimize the morbidity and mortality associated with CVST. The breakdown of the blood-brain barrier and drop in cerebral perfusion pressure caused by CVST can result in cerebral edema, local ischemia, and intracerebral hemorrhage. Despite treatments, the death rate for CVST patients remains at 10%, with 10% of patients receiving poor long-term prognosis. CVST patients are typically younger, including pregnant women and young mothers, and have seen a statistically significant rise during the COVID-19 outbreak as a result of the SARS-CoV-2 disease and some vaccinations.
Vortex ultrasound, also known as acoustic orbital angular momentum, is a unique form of acoustic wave that is characterized by its helical wavefront that rotates as it travels through space. This innovative technology has been utilized in the development of various acoustofluidic techniques for contact-free and biocompatible manipulation of fluids and particles. In the new tool aimed at combating CVST, a single transducer has been designed to produce the vortex effect and is compact enough to be integrated into a catheter for delivery to the site of the blood clot through the circulatory system.
In an effort to reduce the effects of CVST, researchers have employed vortex ultrasound technology to develop a new tool. This acoustic wave has a helical wavefront which rotates as it travels through space, allowing for a single, small transducer to be created. The transducer is small enough to be inserted into a catheter, which can then be used in the circulatory system. With this tool, many acoustofluidic technologies have been developed and implemented, which can manipulate fluids and particles in a biocompatible and contact-free manner. These results suggest that this approach could be effective in treating CVST. Any catheterization or surgical intervention carries the potential for harm, such as damaging the blood vessel. To evaluate the safety of this procedure, the researchers conducted experiments on animal blood vein samples using vortex ultrasound. There was found to be no damage to the blood vessel walls, nor to the red blood cells and therefore, suggest that this approach could be effective in treating CVST.
“Based on available data, pharmaceutical interventions to dissolve CVST blood clots take at least 15 hours, and average around 29 hours,” Shi says. “During in vitro testing, we were able to dissolve an acute blood clot in well under half an hour.” stated Chengzhi Shi, co-corresponding author of the work and an assistant professor of mechanical engineering at Georgia Tech. “Existing techniques rely in large part on interventions that dissolve the blood clot. But this is a time-consuming process. Our approach has the potential to address these clots more quickly, reducing risk for patients,”
The team is now working to verify the viability of this technique for CVST treatment through tests with an animal model, with the ultimate goal of pursuing clinical trials. Should the ultrasound prove to be a successful clinical application, it will likely be cost-comparable to other interventions used to treat CVST.