Designing self-cleaning vascular grafts to combat cardiovascular disease

One person in the United States dies every 34 seconds because of cardiovascular disease. 

Individuals with a build-up of plaque within their body’s arterial walls – or atherosclerosis – are more likely to be part of that statistic than others living with a heart or blood-related illness. The disease can cause stroke, myocardial infarction and peripheral vascular disease. 

Atherosclerosis, like other cardiovascular diseases, can be treated through a vascular bypass procedure, where a synthetic graft is attached to a blood vessel and redirects blood flow around a blocked artery. But, for patients that have smaller or unusable blood vessels, a synthetic graft can fail because of a blood clot or cells accumulating in the area.

“These patients are in need of a bypass surgery,” Jonathan Vande Geest, professor of bioengineering at the University of Swanson School of Engineering, explained. “The challenge is developing a synthetic graft that remains patent in both the short and long term.” 

Vande Geest and a team of multidisciplinary researchers are developing self-cleaning vascular grafts to support patients needing bypass surgery. A self-cleaning graft would be able to repel microscopic blood cells called platelets and thereby reduce the risk of a blood clot by preventing the formation of protein layers near the affected area. 

Vande Geest and his team used the mechanical, fluid transport, and geometric properties of a layered and porous vascular graft inside a porohyperelastic model – models that demonstrate water saturating a porous medium – to increase the speed of the blood traveling radially inward from the luminal vessel wall to promote self-cleaning.  

 “This is just a start toward understanding self-cleaning grafts,” Vande Geest said. “More research will be needed to demonstrate improved functionality both on the bench and in appropriate preclinical animal models.” 

The article, “Optimizing the Porohyperelastic Response of a Layered Compliance Matched Vascular Graft to Promote Luminal Self-Cleaning,” was published in the Journal of Biomechanical Engineering in February 2023. 

This research is a continuation of Vande Geest’s work with vascular grafts. In early 2022, his team received more than $2.6 million from the National Institutes of Health to improve long-term graft functionality. 

In addition to Vande Geest, the project also includes: 

• University of Pittsburgh: Ali Behrangzade, William R. Wagner
• University of Arizona: Bruce R. Simon