‘Artery on a chip’ could predict stroke risk

An artery-on-a-chip could help predict a person’s stroke risk by recreating their blood vessels and blood flow, researchers say.

Described as a patient’s “physical twin”, the tool models the shape of an individual artery and the way blood moves through it.

It could provide more detailed information than measurements of arterial narrowing alone, although further clinical testing is needed.

Researchers from the University of Sydney and the Heart Research Institute in Australia developed the platform.

“This idea was born out of a critical clinical gap. We know that even patients at ‘low risk’ can suffer from severe or fatal strokes. We wanted to find a better way to predict this risk,” said author Lining Arnold Ju, from the University of Sydney.

An ischaemic stroke occurs when a clot or fatty deposit blocks a blood vessel supplying the brain.

When the supply of blood and oxygen is cut off, brain cells die within minutes.

Assessing risk is difficult because whether a clot breaks away from where it formed, travels through the bloodstream and becomes lodged in another vessel depends on factors unique to each person.

The platform recreates the geometry of a patient’s carotid artery, one of the major blood vessels carrying blood to the brain.

“Our work recreates precise, patient-specific carotid artery geometries,” Ju said.

“The physical twin also uses cells that more closely mimic the dynamics of blood flow in these structures.”

The researchers reconstructed carotid arteries from six patients with different levels of vascular disease.

They used computer modelling to calculate how blood moved through each artery and found substantial differences in local flow, even when the level of narrowing was similar.

The team then used a laser to create a small injury in the underlying collagen.

The clotting patterns differed according to the three-dimensional shape of each artery.

“Our findings suggested that three-dimensional vascular shape and local flow disturbances matter far more than simple narrowing,” said first author Yunduo Charles Zhao, from the Heart Research Institute in Newtown, Australia.

Zhao was motivated to move his research towards predictive stroke diagnosis during his PhD after his grandmother died from a stroke.

“We hope these tools will allow us to study drugs aimed at reducing the risk of stroke and to eventually provide personalised treatments for each patient based on their anatomy.”

The team is recruiting people who have experienced a stroke for a clinical trial evaluating how the technology could directly benefit underserved patients.

Researchers said the platform could also help investigate peripheral artery disease, deep-vein thrombosis and aneurysms.

Peripheral artery disease restricts blood flow to the limbs, while deep-vein thrombosis occurs when a clot forms in a deep vein. An aneurysm is a weakened, bulging section of a blood vessel.