Human veins have been grown by U.S. scientists who hope to revolutionize heart bypass surgery and kidney dialysis procedures.
Scientists from Duke University, East Carolina University and Yale University said Wednesday they can create "fully formed vascular grafts" in eight to 10 weeks through a process that takes smooth muscle cells from a human cadaver and grafts them onto tubes made of polyglycolic acid.
The researchers said the bio-engineered veins could also be stored in saline solution and surgeons would be able to pick them "off the shelf" for use in a sick patient.
"These can be made ahead of time and then are ready to go whenever they are needed," said the paper, which was published in the journal Science Translational Medicine.
"Currently, grafting using the patient's own veins remains the gold standard," said report author Dr. Alan Kypson of the Brody School of Medicine at East Carolina University.
"But, harvesting a vein from the patient's leg can lead to complications, and for patients who don't have suitable veins, the bio-engineered veins could serve as an important new way to provide a coronary bypass," he added.
The veins are sterile, so they are not at risk of being rejected by the patients' immune system and can be made in a variety of sizes for use in different operations.
The veins have been tested in baboons and dogs and were not rejected by the animals' bodies and functioned well for six months, said the researchers. Clinical trials in humans were expected to begin soon, according to a spokeswoman from Humacyte, a regenerative medicine company based in North Carolina that also contributed to the study and funded the research.
Around 400,000 coronary bypass procedures are performed annually in the US, says the American Heart Association.