Canadian Researchers Capture on Tape How Clot-Busters Work

Researchers in Toronto have managed to capture the first direct evidence through which ultrasound-stimulated microbubbles lead to a blood clot's demise, a new study published in the journal Applied Physics Letters reveals.

Previous work on this technique, which is called sonothrombolysis, has focused on indirect indications of its effectiveness, including how much a blood clot shrinks or how well blood flow is restored following the procedure. The Toronto team, which included researchers from the University of Toronto and the Sunnybrook Research Institute, tried to catch the clot-killing process in action. Using high-speed photography and a 3-D microscopy technique, researchers discovered that stimulating the microbubbles with ultrasonic pulses pushes the bubbles toward the clots. The bubbles deform the clots' boundaries then begin to burrow into them, creating fluid-filled tunnels that break the clots up from the inside out.