Navigation Links
Math from the heart: Simulating stent design and coating

Suncica "Sunny" Canic was good at math in school, so that's what she pursued as a career. But she always liked medicine, too. When she moved to Houston, Texas, and met some cardiologists at a party, she started talking with them about what they doand knew she could help them.

"I realized we could provide them with a fluid dynamics and mechanics point of view to help them make decisions about, for example, which stent grafts they use in their procedures," she says.

Stents are tiny mesh tubes made from metal alloys that hold blood vessels open after they've been clogged with disease-causing plaque. Even though stents are designed to be compatible with the human body, they sometimes cause unwanted reactions, such as blood clots and scar tissue formation. So scientists have tried to coat stents with cells that make the tiny tubes even more compatible.

But these, too, aren't yet perfect, says Canic. Blood flowing over a coated stent can still clot or tear cells away. This is, as Canic puts it, "not good."

A professor of mathematics at the University of Houston, Canic makes computer models to guide the search for a better stent coating. She also uses computer models to study the strengths and weaknesses of different stent structures. Supported by a joint grant from the National Institute of General Medical Sciences, part of the National Institutes of Health, and the National Science Foundation, her work could help manufacturers optimize stent design and help doctors choose the right stents for their patients, ultimately improving patient outcomes.

Computer scientists usually model stents in three dimensions. Keeping track of about 200,000 points, or nodes, along the stent mesh, the models are massive. Together with a collaborator at the University of Zagreb in Croatia, Canic wrote a much simpler program that approximates stents as meshes of one-dimensional rods. It let them achieve the same result using just 400 nodes.

Using their simplified model, Canic and her collaborator have examined the designs of several stents on the market to see which structures seem to be best for specific blood vessels or procedures. For instance, they found that stents with an "open design"where every other horizontal rod is taken outbend easily, which makes them good to put in curvy coronary arteries.

Canic has also used the model to design a stent with mechanical properties specifically tailored to an experimental heart valve replacement procedure. She found that this specialized stent works best for the procedure when it's stiff in the middle and less stiff at the ends.

And she has found that combining bendiness with radial stiffnesswhere you can bend the stent into a U shape, but you can't squeeze the tube shutproduces a stent with less chance of buckling than those that are currently in use.

The most rewarding part of her work, says Canic, is that "we can use mathematics for something useful, connected to real-world problems." She reports that her collaborators are already putting the results of her simulations into practice.

Her greatest challenge, meanwhile, is serving as an ambassador of mathematics to the medical and bioengineering communities.

In the beginning, she says, it was difficult to collaborate with people from different disciplines who speak different scientific languages. "But once they saw that there is a lot of information there that could be helpful, it has been much easier," she says. "Now people want to talk to us from the medical center. They come to us and ask questions, and that's good."

Today, Canic is helping a team at the Texas Heart Institute study an unusual source for stent coating: ear cartilage. The team believes this easy-to-harvest tissue will make stents more biocompatible, though they don't yet know how ear cartilage cells grow or behave in environments like human blood vessels.

So Canic is using her computer programs to simulate how blood interacts with the stent-coating cartilage cells and how the cells stick (or don't) to the stent surface. She plugs in different fluid thicknesses and shear forces of blood flowing over the stent to see what might encourage the cartilage on freshly coated stents to stabilize quickly. The models have helped her collaborators home in on the best conditions to test in follow-up experiments as they search for ways to pre-treat stents before doctors implant them.

Canic wants to keep collaborating with the medical community as she moves forward with her research. She plans to look at biodegradable stents, as well as simulate the fluid dynamics of regurgitating mitral valves (where some blood flows backwards in the pumping heart) to help doctors more accurately diagnose the condition using ultrasound.

"Certainly I am going to continue working in this area," she says. "It is very rewarding."


Contact: Emily Carlson
NIH/National Institute of General Medical Sciences

Related medicine news :

1. NEJM Publishes Trial Results Demonstrating Bard FLAIR Endovascular Stent Graft Is Superior To Balloon Angioplasty For Failing Dialysis Grafts
2. Stents May Be Effective Weapon Against Stroke
3. American Stroke Association Late-Breaking Science Report: Surgery, Stenting to Open Blocked Neck Arteries Similar in Safety, Efficacy, But Show Differences in Stroke, Heart Attack and Death Rates at Certain Ages
4. Stents as good as surgery for clogged carotid arteries
5. EPIC study finds new embolic protection device had 97.5 percent success rate during carotid artery stenting
6. Male batterers consistently overestimate rates of violence toward partners
7. EXCEL trial will determine safety and efficacy of drug-eluting stents vs. bypass surgery
8. Aspirin Alone Works Best to Prevent Clots a Year After Stenting
9. Stenting May Save Legs
10. Bailout stenting successful treatment for infants with constricted aortas
11. Prenatal Healthcare Providers Inconsistent In Weight Gain Counseling
Post Your Comments:
Related Image:
Math from the heart: Simulating stent design and coating
(Date:11/24/2015)... Church, VA (PRWEB) , ... November 24, 2015 , ... ... — 1:30 p.m. – 3:00 p.m. EST, , FDA has long ... regulations. CLIA regulations apply to performing the tests and do not meet the device ...
(Date:11/24/2015)... ... November 24, 2015 , ... The ... waive paid entry and parking fees at several of their most popular properties, ... Great Barrington in support of REI’s Black Friday #OptOutside Campaign. The Trustees encourage ...
(Date:11/24/2015)... ... November 24, 2015 , ... In response to recent news highlighting Oxycodone ... prescription opioids in the United States grew 400 percent between 1999 and 2010, far ... involved in 37 percent of all fatal drug overdoses. (1) , While oxycodone and ...
(Date:11/24/2015)... ... November 24, 2015 , ... Cancer patients, survivors, caregivers, family ... a live taping of the next CURE Connections® video series on ... 2015 Symposium at Georgetown University Hotel & Conference Center in Washington, D.C. , ...
(Date:11/24/2015)... ... November 24, 2015 , ... American Family Care (AFC), the nation’s leading provider ... pop-up clinic located in Metro Atlanta’s North Point Mall. The clinic is designed to ... The location is scheduled to operate through Dec. 24. , Holiday Pop-Up Clinic , ...
Breaking Medicine News(10 mins):
(Date:11/24/2015)... , November 24, 2015 ... of the University of Bern ... Nutrition of the Bern University Hospital "Inselspital" are proud ... develop a novel generation artificial pancreas. Combining a fully ... for diabetic patients with the unequalled accuracy of an ...
(Date:11/24/2015)... , November 24, 2015 st  Scientific Assembly ... America (RSNA) taking place in Chicago ... 1122, Hall A. --> st  Scientific Assembly and Annual ... (RSNA) taking place in Chicago on ... A. --> Molecular Dynamics will present its revolutionary whole ...
(Date:11/24/2015)... uptake of recently approved and pipeline premium products for Type 1 Diabetes ... says GBI Research . --> The ... Mellitus (T1DM), will be a key driver of market growth to 2021, ... The uptake of recently approved and pipeline premium products for Type 1 ... 2021, says GBI Research . Type ...
Breaking Medicine Technology: