The tissue engineering of large blood vessels is a very different matter from growing the intricate networks of small blood vessels needed to support tissue. The former goal is far less challenging, for one thing, and researchers are thus further along in bringing the creation of new veins and arteries to the clinic. Here is news of progress on that front:
In a first-of-its-kind operation in the United States, a team of doctors at Duke University Hospital helped create a bioengineered blood vessel and implanted it into the arm of a patient with end-stage kidney disease. The procedure, the first U.S. clinical trial to test the safety and effectiveness of the bioengineered blood vessel, is a milestone in the field of tissue engineering. The new vein is an off-the-shelf, human cell-based product with no biological properties that would cause organ rejection.
Using technology developed at Duke and at a spin-off company it started called Humacyte, the vein is engineered by cultivating donated human cells on a tubular scaffold to form a vessel. The vessel is then cleansed of the qualities that might trigger an immune response. In pre-clinical tests, the veins have performed better than other synthetic and animal-based implants.
Clinical trials to test the new veins began in Poland in December with the first human implantations. The U.S. Food and Drug Administration recently approved a phase 1 trial involving 20 kidney dialysis patients in the United States, followed by a safety review. Duke researchers enrolled the first U.S. patient and serve as study leaders. The initial trial focuses on implanting the vessels in an easily accessible site in the arms of kidney hemodialysis patients. More than 320,000 people in the United States require hemodialysis, which often necessitates a graft to connect an artery to a vein to speed blood flow during treatments.
If the bioengineered veins prove beneficial for hemodialysis patients, the researchers ultimately aim to develop a readily available and durable graft for heart bypass surgeries, which are performed on nearly 400,000 people in the United States a year, and to treat blocked blood vessels in the limbs.