Artificial blood vessels developed in the lab can grow with the recipient

Doing surgeries involving artificial blood vessels is nothing new. But surgeries with regenerative blood vessels? That’s unheard of.

The need

Congenital heart defects (CHD’s) effect about 1% of all newborns in the United States (source). Often these children need to have surgery to replace or re-structure their blood vessels, and replacement pieces of vessels can be implanted into the patient.

Complications arise when the child continues to grow, year by year. New vessels, or grafts, have to be replaced as the child’s body changes in shape and size. Thus repeat surgeries, and quite serious surgeries, are required.

Most doctors prefer to permanently fix a problem with surgery if they can. They would rather not have to put anyone, child or adult, through repeat surgeries if it can be avoided.

A fantastic solution

Only recently has a solution to this challenge been found for congenital heart defect patients.

Researchers at the University of Minnesota Department of Biomedical Engineering have developed a vessel that can actually grow with the patient.

Here’s how they did it. First the scientists took some skin cells from a sheep, and then combined them with a gelatin-like material called fibrin into a tube shape. Next, to help stimulate cell growth and strengthening of the two components, they used a bioreactor to pump nutrients into the vessel, essentially giving it “exercise”. This helped to create a tube-shaped vessel that is actually stronger than a real blood vessel, which reduces the chances of it bursting in a patient.

To round off their procedure, the scientists rinsed off the sheep’s skin cells, leaving the tube shaped vessel. This was done to ensure that the body that would be taking the vessel did not reject the cells.

Amazingly, when they inserted the vessel surgically to fix blood vessels in several test subjects (sheep), all of the subjects bodies accepted the vessels and their cells actually formed around and with the vessel.

Essentially this indicates that the scientists have created a vessel that is now deeply connected with the bodies own cells, and can grow as the patients body grows.

“This might be the first time we have an ‘off-the-shelf’ material that doctors can implant in a patient, and it can grow in the body… In the future, this could potentially mean one surgery instead of five or more surgeries that some children with heart defects have before adulthood.”

– Robert Tranquillo, Ph.D., University of Minnesota

How about results?

What’s even more encouraging were the trials’ results.

“At 50 weeks of age, the sheep’s blood vessel graft had increased 56 percent in diameter and the amount of blood that could be pumped through the vessel increased 216 percent. The collagen protein also had increased 465 percent, proving that the vessel had not merely stretched but had actually grown. No adverse effects such as clotting, vessel narrowing, or calcification were observed” (ScienceDaily).

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