Blood clots are unfriendly to the patients with cardiovascular disease. But now we have a new tool against blood clots. Researchers at North Carolina State University and the University of North Carolina at Chapel Hill have developed a new surgical tool that uses low-frequency intravascular ultrasound to break down blood clots that cause deep vein thrombosis. The tool is the first ultrasound "drill" that can be aimed straight ahead, allowing doctors to better target clots — which holds promise for significantly reducing treatment time. At present, the technology has been tested only in synthetic blood vessels. The research is published in the Nature Publishing Group journal Scientific Reports.

Existing intravascular ultrasound tools for clearing clots emit ultrasound waves laterally. This makes it harder to target clots exclusively, meaning that the ultrasound can also damage surrounding blood vessels. However, ultrasound breaks the clots into small pieces, so doctors don't need to use large doses of blood thinner to dissolve the clot remnants.

Another technique uses a diamond-tipped drill to effectively chew through clots. This is more targeted, posing less risk to blood vessels. However, this technique breaks the clot into relatively large pieces, requiring higher doses of blood-thinning drugs -- which can cause risks in turn.

Considering the limitation of the existing methods, the ultrasound drill we introduce today is surely a better choice. "Our new ultrasound tool is forward-facing, like a drill, but still breaks down clots into fine particles," says Xiaoning Jiang, a professor of mechanical and aerospace engineering at NC State and corresponding author of a paper describing the work. "Our approach improves accuracy without relying on high doses of blood thinners, which we hope will reduce the risks across the board. “