American Heart Association
News Release (AHA)
April 25, 2013
- Artificial blood vessels remained durable in an animal trial and show promise for patients with end-stage kidney disease.
- The "off-the-shelf" blood vessels withstood frequent needle punctures, were not rejected by the immune system, and were safely stored in a refrigerator for up to one year.
"Off-the-shelf" blood vessels could one day reduce some complications of dialysis treatment, according to preliminary research presented at the American Heart Association's Emerging Science Series Webinar.
Scientists bioengineered an artificial blood vessel by seeding human aorta cells onto a biodegradable mesh tube. In the process, a tubular vein develops in two months as the growing cells secrete proteins and the mesh support structure dissolves. The new vessel is then prepped in a way that minimizes chances of an immune reaction in the recipient.
In the study, bioengineered vessels implanted in primates for six months remained durable and didn't have the common complications of synthetic grafts: blood clots, rejection and thickening of the adjacent vein that can obstruct the graft.
"Eventually, off-the-shelf blood vessel grafts might be used in kidney dialysis patients and potentially in many vascular procedures, such as bypassing blocked arteries in the legs, repairing vessel damage after trauma, or in coronary bypass operations," said Shannon L. Dahl, Ph.D., lead author of the study and co-founder and vice president of scientific operations at Humacyte, Inc. in Research Triangle Park, N.C.
When dialysis is needed because of kidney failure, the first-line approach is to surgically create an artificial connection (fistula) between an artery and vein in the arm. But, about half of kidney patients don't have healthy veins, so a synthetic vessel made of polytetrafluoroethylene (PTFE) is used instead.
Synthetic grafts are subject to many complications and about half fail within a year, said Dahl, requiring replacement surgery.
"The artificial vessels had excellent resistance to obstruction and clotting and tolerated the repeated needle punctures required for dialysis," Dahl said.
Based on these results researchers have launched a multi-center European clinical trial, and the FDA has authorized a multi-center U.S. clinical trial, to assess safety and function of biological grafts in dialysis patients who can't have a fistula created.
Co-authors are: Jeffrey H. Lawson, M.D., Ph.D.; Heather L. Prichard, Ph.D.; Roberto J. Manson, M.D.; William E. Tente, M.S.; Alan P. Kypson, M.D.; Juliana L. Blum, Ph.D.; and Laura E. Niklason, M.D., Ph.D.