A new study published in the journal, Science Translational Medicine shows scientists have grown blood vessels from human tissues that surgeons could eventually use for heart bypass and dialysis patients.
- Typically, a heart patient’s own vein is taken from the leg and sewn into the heart during coronary artery bypass graft surgery to circumvent a blockage;
- More than 500,000 such procedures are done in the US each year but, not all patients have suitable vessels for transplant and the grafts may not be the correct size.
The veins could also be available for dialysis. Researchers say the bioengineered veins come with less risk of infection, obstruction or clotting than current synthetic grafts that heart surgeons say have poorer clinical outcomes.
- Perhaps more exciting, the blood vessels can be made to fit the artery surgeons aim to bypass. Arteries are only 2 to 3 millimeters in diameter but a vein from a leg could be up to1 one centimeter in size;
- Such mismatches may lead veins to become blocked over time after surgery as blood stagnates and clots, said study author Dr. Alan Kypson, a professor of cardiothoracic surgery at the Brody School of Medicine at East Carolina University.
The Bottom Line: Investigators have grown blood vessels from human cadaver tissues on tube-like scaffolds made from a biodegradable polymer used in sutures. When the scaffold degraded, fully formed blood vessels were left. These were then stripped of the original donor cells to make sure they wouldn’t trigger an immune response when transplanted. In a series of tests, the human blood vessels kept their strength and elasticity and remained unclogged after scientists stored them for a year. Synthetic veins can be an important part of treatment but are not always suitable. But, for the first time, a bioengineered vein produced from human cells can be stored for up to 12 months in a simple manner. When the grafts were tested on baboons and dogs that had surgery, the vessel acted like a pipe between an artery and vein to restore blood flow. Doctors use the same graft approach in kidney dialysis, which filters blood through a machine to clean out waste products when kidneys no longer carry out that function properly. The researchers believe they are ready to try clinical testing for dialysis, which is typically less risky than heart surgery however, the first human trials would be in 2 or 3 years.