Using aerospace engineering concepts to improve treatment of cardiovascular disease

Her background is in aeronautical engineering, and she earned her doctorate from Stanford University after writing her dissertation on aerodynamic noise control by optimal shape design.

Surprisingly, that’s what makes Alison Marsden, a professor of mechanical and aerospace engineering at UC San Diego’s Jacobs School of Engineering, perfectly suited for her role in treating cardiovascular disease in babies. She leads a group of researchers at UC San Diego’s Cardiovascular Biomechanics Computation Lab.

“I try to take some of the same concepts and principles from aerospace engineering and bring them to treating cardiovascular diseases,” Marsden said. “Flow is flow, whether you are looking at flow over a wing on an airplane or blood flow to an aorta.

“When you’re dealing with aerospace engineering, you’re working with heavy-duty numerical simulations to replicate wind tunnel testing and accelerate the design process. But those tools didn’t really exist in medicine. So what we’ve tried to do is apply those same predictive quantitative tools and computational methods when dealing with surgeries for congenital heart defects.”

As part of her research at the school, Marsden has helped create computer simulations that have led to major advances in analyzing and predicting how a particular patient’s vascular system will react to a specific procedure.

“This gives us a way to safely innovate so we can test out radically different surgical approaches on a computer rather than on a patient,” Marsden said.

Her colleagues are impressed.

“Dr. Marsden’s research provides valuable insights into clinical decision-making, surgical planning and the mechanisms of diseases,” said Andrew Kahn, associate professor of medicine, Division of Cardiology, at the UC San Diego Sulpizio Cardiovascular Center.

Young patients, revolutionary surgeries

Among the advancements Marsden’s research has helped bring about is a revolutionary change in the protocol for operating on babies born with what is, in essence, half a heart.

Until now, newborns with a single ventricle in the heart had to undergo three operations to repair the damage. But Marsden and her team of researchers at UC San Diego, in collaboration with cardiothoracic surgeon Tain-Yen Hsia of the Great Ormont Street Hospital for Children and UCL Institute of Cardiovascular Science in London, last year designed computer simulations measuring blood flow under different conditions that enabled surgeons to combine the first and second procedures.

The approach still has to be refined and tested in animal models before it can enter the clinic.

In 2009, Marsden and her group also used engineering principles to redesign the third procedure in a series of surgeries — known as the Fontan procedure — which is specifically used to treat children with single-ventricle heart defects. Six patients underwent the new type of graft, which is shaped like a Y and connects the inferior and superior vena cava (which carry deoxygenated blood) to the pulmonary arteries, and all six are reportedly doing well today.

“The procedure is one of the few examples of a computer simulation-derived design going into clinical practice for cardiac surgeries,” Marsden said.

On another front, researchers at UC San Diego’s Jacobs School of Engineering are working to create blood flow simulations to improve cardiac pumps critical for infants waiting for a heart transplant. Marsden noted that the only pump currently approved by the FDA comes with a high risk of blood clots in patients, making improved blood flow a paramount objective.

Flying into medicine

So why would an aerospace engineer make such a huge leap to medicine?

“I wanted to work in an area with a more direct human application,” Marsden said, noting that congenital heart defects affect one in 100 babies in the U.S. That makes them the leading cause of infant mortality.

The key to her success has been in working with others from different fields.

“Dr. Marsden has an excellent grasp of the diagnostic and therapeutic challenges faced by clinicians,” Kahn said. “She has established collaborations with a number of physicians to facilitate the transfer of her research results to the clinical setting.”

“We’re bringing fundamental science into our approach to engineering and fundamental engineering into our approach to medicine,” said Marsden. “We do a lot of one-size-fits-all surgery on patients, and it would be nice to customize it so that everybody can have the surgery that is uniquely fitted and best for them. Ultimately, we hope to help improve the lives of patients facing the challenges of cardiovascular disease.”

David Ogul, Brand Publishing Writer

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