Newswise — Dr. Tom Merrill is on a mission: keep people walking, talking and breathing after a stroke.
Thanks to a $207,000 grant from the National Institutes of Health, the assistant professor of mechanical engineering at Rowan University, Glassboro, N.J., will be able to explore more options to do just that.
The funding is for Merrill’s project named “A combination endovascular device: thrombectomy with localized hypothermia,” which he and his team are working on in the South Jersey Technology Park at Rowan University in nearby Mantua Township.
Merrill and his associates are expanding on work they previously have done as part of his firm FocalCool to develop a device called the “CoolGuide Catheter,” which could be used during emergency angioplasty to help people suffering a heart attack in the midst of the heart attack. The new project will dovetail with some existing technology that “pulls” clots from the brain after a stroke. Present devices made of a shaped memory alloy (trade name Nitinol) that changes shape based on temperature act like a corkscrew to enter the clot and drag it out of the brain.
Doctors use a three-part system to removal clots: a large guide catheter, a micro catheter and a thrombectomy-removal catheter.
The large guide catheter goes inside the carotid artery. The micro catheter goes further into the vascular system deep into the brain. The thrombectomy-removal catheter, which enters through the first two catheters, does the actual work, similar to a corkscrew, pulling the clot out. Afterwards, physicians introduce warm blood into the brain.
“You’d think that fresh warm blood would be helpful for the brain, “ he said. “But it’s not, because of something that is not very well understood called reperfusion injury.”
When cells lose blood flow, he explained, they are programmed to die. When blood flow is reintroduced into the tissue, it is possible to re-energize the cells and to push them towards death. This can be significant. He said, for instance, if a brain injury measures 100 grams, half of that might be caused by the reperfusion.
“What we are trying to do is tame that reperfusion injury,” Merrill said. “The 50 percent of damaged cells we’re trying to save may be clinically relevant in the case of strokes.”
Merrill is working on the project with his wife, Denise, a senior research engineer; Jennifer Akers, a research scientist and Rowan graduate; Adam Parker, Ben Chapman, and Kristen Linderman, student interns; and Tony LaBarck, a Rowan master’s student who graduated in December and is a computational model consultant. They are exploring whether cooling blood externally and reintroducing it into the brain at a lower temperature will cause less injury.
Additionally, they are collaborating with Dr. Alex Abov-Chebl, University of Louisville; and Dr. Jay Yadav, CEO of Cardiomems, Atlanta, and Synecor, Durham, N.C.
Right now, the Rowan-based team is developing product requirements and math models of the thermal fluid physics. They will test prototypes in a glass model that mimics the structure of the vascular system in the brain. They are using pumps to mimic the heart and heaters to maintain normal body temperatures.
Merrill said he intends to have results on the first stage of the work in the summer and to apply for further funding.
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