Moser’s Model will Help Personalize Brain Surgery
Each year, about 30,000 people in the United States experience hemorrhagic strokes, when blood from an artery suddenly bleeds into the brain. The drastic increase in pressure can damage nearby brain tissue, while disrupted blood flow starves other areas of oxygen.About half of hemorrhagic strokes are caused by cerebral arteriovenous malformations (AVMs), where arteries and veins connect directly. Usually, arteries and veins are separated by a network of capillaries, sites of gas exchange which allow blood pressure to decrease gently.
“High-pressure arterial blood going into that lower-pressure vein can eventually lead to tearing of the vein,” explained Mackenzie Moser, a senior in the University of Tennessee’s Department of Medical, Aerospace, and Biomedical Engineering (MABE).
Though AVMs are present at birth, they are essentially undetectable until a stroke or related event occurs. Afterward, doctors can inject a liquid embolic (gelling agent) into the AVM which solidifies and redirects blood flow.
However, since so little is known about AVMs prior to illness, the treatments are hard to personalize.
“There’s a lot we don’t know about how the hemodynamic environment—the internal blood pressure, temperature, and flow rate—actually affects the embolic once it’s solidified,” said Moser.
For the past year, Moser has been working to understand hemodynamic conditions in AVMs as a member of the UT Cardiovascular Biomechanics Lab run by Assistant Professor Bryan Good. She presented her research at the Society of Women Engineers 2024 conference (SWE 2024)—an international gathering with thousands of attendees—and won first place in the undergraduate Rapid-Fire Collegiate Competition.
This fall, she will continue her foundational research as Good’s newest PhD student.
“The fluid mechanics surrounding cerebral AVMs and their treatment options are greatly understudied,” Good said. “That provides an opportunity for our lab to make significant contributions to the field, and I think Mackenzie is going to excel in graduate school.”
Cerebral arteriovenous malformations resin model with a clamp on it.
Early Research Opportunities
Moser had considered going to medical school for cardiology, but the pull of engineering was too strong. She was excited to discover MABE, where the balance of math, science, and healthcare applications suited her interests perfectly—and where she knew she could get hands-on experience early.
“A lot of schools said their research was saved for either seniors or graduate students,” Moser recalled. “During the engineering tour at UT, it seemed like there were a lot of research opportunities no matter what your major was.”
After working in a tissue engineering lab for two years, Moser reached out to Good in the fall of her junior year. Good quickly realized that she was the perfect fit for his newest research project—so new that he had not even submitted the grant proposal yet.
“Most of the undergrads in my lab work underneath one of my PhD students on experiments related to their theses,” Good said. “However, I was looking for an undergraduate student with the right interests and motivation to develop this AVM project from scratch.”
“I said, ‘This sounds like something I would love to do, but I don’t know anything about it,’” Moser recalled. “Dr. Good said, ‘That’s okay; I also don’t know anything about it. We’re going to figure it out together.’”
The Groundwork of Blood Flow
Moser began studying the flow dynamics of water through a clinically accurate resin model of an AVM in spring 2024. This January, with funding from her competitive UT Advanced Undergraduate Research Activity (AURA) grant, she started testing how the fluid dynamics in the resin model changed when she placed barriers in different areas.
As part of her doctoral thesis, Moser hopes to integrate her ongoing experimental data into a computational fluid dynamics (CFD) model that can be tweaked to emulate an individual patient’s AVM—and how the malformation would react to treatment.
“Physicians would be able to input patient-specific data, simulate whichever embolic they want to use, and see what those outcomes would look like,” Moser explained. “It’d be a much more patient-targeted type of therapy.”
Good looks forward to helping Moser continue her AVM research and expand into complementary projects in his lab, like studying the fluid dynamics of blockage removal in patients who have suffered from ischemic (clot-related) strokes.
Moser’s undergraduate research not only gave her the experimental basis for multiple clinically needed CFD models; it has also given her a healthy outlook on the kinds of research setbacks students don’t experience in lab classes.
“It’s really taught me patience,” she said. “If I make a mistake, I’m just going to have to learn from it. And that’s okay. Trial and error are what research is all about.”
Contact
Izzie Gall (865-974-7203, egall4@utk.edu)