New research into strokes may one day limit the damage of this troubling disease that affects millions of Americans. Despite the progress that’s been made over the last decades, strokes are still the most common cause of long-term disability and the third most common cause of death in the United States. Every year, more than 795,000 Americans experience a stroke, which occur when a clot forms in an artery or blood vessel, restricting the flow of blood to the brain and depriving it of oxygen.
Breaking up these clots quickly and safely is the key to stopping a stroke and reducing the damage potential. Ground-breaking research on this deadly disease is using the power of supercomputing to explore a new technique that could be safer and more effective than either surgery or drugs.
A group of researchers from the Universities of California at Berkeley (UC Berkeley) and San Diego (UCSD) used the supercomputing resources of the National Energy Research Scientific Computing Center (NERSC) to model the efficacy of microbubbles and high intensity focused ultrasound (HIFU) for breaking up stroke-causing clots. The results of their study have been published in Journal of the Acoustical Society of America.
“One day, HIFU could be a useful medical treatment for people who are stroke victims. But before this can happen, we need to establish some fundamental background work, which includes understanding how HIFU accelerates damage to a clot when bubbles are present,” says one of the lead researchers, Andrew Szeri, Professor of Mechanical Engineering at UC Berkeley.
The supercomputing allocation is enabling the researchers to generate enough data to make a case for further study. “Without some kind of preliminary data, it’s a non-starter; there’s just no way for us to find funding,” says Szeri.
The research has an interesting backstory. Currently, the only federally approved treament for stroke-causing clots is a drug called tissue plasminogen activator (tPA), but there is only a short window of use, affecting its utility. In the early 1990s, researchers noticed ultrasound scans seemed to potentiate the effectiveness of the anti-stroke drug. A 2004 trial confirmed the connection. Since then, researchers have been experimenting with ways to co-administer ultrasounds to maximize the effectiveness of tPA.
Researchers believed that the microbubble-HIFU technique would be a good replacement for the drug and artificial microbubbles were already used as ultrasound contrasting agents. Subsequent laboratory experiments with cadeavors confirmed their hypothesis, but they still needed to determine doseage and safety. That’s where the supercomputing resources of NERSC came in.
“The supercomputer simulations verified that it is feasible to bust blood clots with relatively low energy, which is important because when the energy is not appropriate bubbles will form.” Generally the artificial microbubbles are harmless, but bubbles released under low pressure can rupture small blood vessels.
Upon securing further funding, the research team will attempt to strengthen the connection between the computational results and actual clot damage from bubbles.