Stanford researchers develop simulations to improve heart surgeries

MRI or CT scans provide physicians with a detailed picture of their patients’ internal anatomy. Heart surgeons often use these images to plan surgeries.

Unfortunately, these anatomical images don’t show how the blood is flowing through the vessels — which is critical, according to Alison Marsden, PhD, a Stanford associate professor of pediatrics and of bioengineering. In the video above, she explains that many surgeons currently use a pencil and paper to sketch out their surgical plan based on the patient’s images. She hopes to change this.

Marsden and her colleagues at Stanford’s Cardiovascular Biomechanics Computational Lab are developing a new technique — using imaging data and specialized simulation software — to predict what is likely to happen during heart surgery.

“What we’re trying to do is bring in that missing piece of what are these detailed blood flow patterns and what might happen if we go in and make an intervention, for example, opening up a blocked blood vessel or putting in a bypass graft,” Marsden said in a recent Stanford Engineering news story.

Their open source software, called SimVascular, loads the imaging data, constructs a 3D anatomical model of the heart and then simulates the patient’s blood flow. It has already been used to help design the surgical plan for several babies born with a severe form of congenital heart disease, Marsden said. However, more research is needed to determine whether the technique improves patient outcomes before it can be widely used in the clinic.

This is a reposting of my Scope blog story, courtesy of Stanford School of Medicine.

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New simulations may guide future brain surgeries

A team of researchers, led by Ellen Kuhl, PhD, a Stanford professor of mechanical engineering, is developing a new simulation tool to help guide surgeons to more safely relieve brain swelling.

Brain swelling can be caused by a trauma, such as a stroke, tumor or traumatic brain injury. This swelling builds up pressure inside the skull that can lead to brain damage or death, so surgeons sometimes perform a decompressive craniectomy — removing a large portion of the skull to allow the brain to mushroom out. But the surgeons need to know where and how big to cut the skull, which is no easy task.

A recent news release explains,

“… The shape of the brain is essential to its function. It consists of billions of fragile filaments, called axons, bundled together in purposeful patterns. When parts of this amalgam bulge out, axons stretch and shear. Surgeons currently rely on experience to limit the collateral damage that might occur when dire circumstances force them to perform a decompressive craniectomy.

‘This is a new tool to help surgeons decide where and how big to make the hole, by giving them a way to visualize the effects of the procedure on the brain tissue,’ Kuhl said.”

Kuhl is working with Johannes Weickenmeier, PhD, a postdoctoral research fellow at Stanford, and Alain Goreily, PhD, a professor of mathematics at the University of Oxford, to create mathematical models based on magnetic resonance brain images. These simulations will predict how an injury affects specific parts of the brain — showing the predictions on a color-coded brain map, with extreme damage in red, mild damage in green and minimally affected areas in blue.

The team then used these maps to “play what-if scenarios to illustrate how skull openings of different sizes in different regions affect the axons inside the brain,” the news release states.

The researchers plan to work with neurosurgeons to improve their new simulation tools, hoping one day to allow neurosurgeons to accurately peer beneath the skull and make more informed surgical plans.

Video courtesy of Stanford University.

This is a reposting of my Scope blog story, courtesy of Stanford School of Medicine.