Blood Vessels Grown From Muscle Cells
Engineered Blood Vessel Grafts Could Be Used for Heart Bypass, Kidney Dialysis
Bioengineering Blood Vessels continued...
In a final step, researchers washed the collagen-based tubes to get rid of any remaining cells, which could trigger immune reactions in a recipient.
Researchers were able to make the tubes in two sizes. One was 6 millimeters, about the diameter of a standard drinking straw.
The others were 3 to 4 millimeters, about the size of cocktail straws.
They then tested the bioengineered blood vessels in two animal models. After six months, about 88% of the larger grafts were still open and trouble free in baboons. After one month, about 83% of the smaller vessels implanted around the hearts of dogs were still open.
The researchers have not yet tested the bioengineered vessels in humans, but Dahl says this study lays the foundation to do that.
“We estimate that 500,000 patients a year could potentially benefit,” says Dahl.
At least initially, Dahl thinks those will be patients who might need vessels to help reroute blood around blockages in the heart, or for whom doctors need to build an access point so that their blood can be cleaned for kidney dialysis.
“Tissue engineering is a very important frontier in medicine,” says study researcher Jeffrey H. Lawson, MD, a vascular surgeon at Duke University Medical Center.
“Replacing and understanding the complexity of the human body and its specific parts is really quite a challenge. Probably the first places where tissue engineering will become a reality will be in things like blood vessels, because they’re relatively straightforward structurally to construct, even though they’re still amazingly complex,” he says.
A New Way to Replace Blood Vessels
When blood vessels around the heart become dangerously congested with plaques, surgeons will reroute blood flow and bypass the blockages.
To do that, they may take blood vessels from other parts of the body, usually the leg or chest wall.
But there are cases when a person’s own blood vessels can’t be harvested. In those cases, a surgeon may reach for vessels made from synthetic polymers, like Teflon or Dacron, or for vessels donated from cadavers.