Scientists reported on Wednesday they have successfully grown bio-engineered blood vessels that surgeons could someday remove the shelf and implant into patients, something which could ultimately help people lacking healthy veins for coronary bypass surgery or dialysis.
The researchers employed a novel way of using human cells to create the arteries that could permit them to function without triggering a patient’s immune response. Furthermore, unlike other engineered vessels, these may be stored for approximately twelve months, allowing hospitals to ensure that they’re available for immediate use.
“This new type of bioengineered vein allows them to be easily stored in hospitals so that they can easily be bought to surgeons at the time of need,” said Dr. Alan Kypson, Associate Professor of Cardiothoracic Surgery at East Carolina University, who authored a study about the findings.
“Currently, grafting using the patient’s own veins remains the defacto standard. But, harvesting a vein in the patient’s leg can result in complications, as well as for patients who don’t have suitable veins, the bioengineered veins could help as an essential new way to give a coronary bypass,” Dr. Kypson said.
The bio-engineered vessels also provide “decreased potential for infection, obstruction or clotting,” wrote the researchers from Duke, Yale and East Carolina University.
The team created the bio-engineered blood vessels if you take smooth muscle tissues from a human cadaver and grafting them onto tubes made from polyglycolic acid the materials for making dissolvable stitches.
Within eight to 10 weeks, the tubes degrade, abandoning a “fully formed vascular graft”.
The veins happen to be tested in dogs and baboons, and were not rejected by their bodies and functioned well for 6 months.
The vessels can be kept in saline solution for up to 12 months, which may allow surgeons to pick an “off the shelf” vessel for use in a sick patient, they said.
“These may be made ahead of time and then will be ready to go every time they are essential,” they said.
According towards the National Kidney Foundation, 320,000 patients require dialysis, more than half of which don’t have the healthy veins essential for the procedure and must therefore undergo arteriovenous graft (AV graft) placement.
“Most AV grafts that are placed for hemodialysis access consist of a synthetic material, which suffers from significant drawbacks including a high rate of infection, or perhaps a propensity for occlusion due to thrombosis and intimal hyperplasia,” said Dr. Jeffrey Lawson, Associate Professor of Surgery at Duke University School of Medicine and an author of the research.
“Due to high complication rates, each AV dialysis graft requires typically 2.8 interventions over its lifetime just to keep it functioning. Hence, there is a huge clinical need for a functionally superior, off-the-shelf, AV graft that suffers from fewer complications than current materials.”
Humacyte, a North Carolina-based regenerative medicine firm that funded and contributed to the study, said clinical trials in humans would begin soon.
Shannon Dahl, Humacyte’s co-founder and senior director of scientific operations, said veins could be constructed in various sizes according to the kind of operation required.
“We can make the bio-engineered veins in small and big diameter, meaning they can be used for procedures which range from hemodialysis for patients with kidney failure as well as for coronary by-pass.”
Around 400,000 coronary bypass procedures are carried out every year in the U.S., according to the American Heart Association.
“Not only are bioengineered veins offered at time of patient need, however the ability to produce a significant number of grafts from the cell bank allows a reduction in the final production costs, when compared with other regenerative medicine strategies,” Dahl said.
“While there is still considerable research to become done before a product can be obtained for widespread use, we are highly encouraged by the results outlined within this paper and eager to move forward with additional study.”
The study was published February 2 in the journal Science Translational Medicine.