Tissue engineering of larger blood vessels has started to move more rapidly these past couple of years - this is the sort of work in which the vessels are constructed individually for implantation, rather than the very different approaches taken for capillaries and other small vessels that are essential in building three dimensional tissue of any meaningful size. News of a recent trial of blood vessel transplantation has been in the press today, and links to a couple of representative articles follow.
Blood vessels grown in a laboratory were safely implanted in three kidney disease patients, enabling them to have regular dialysis without relying on traditional shunts that caused complications and failed, researchers said. The foot-long vessels were engineered from donor skin cells, grown on sheets and rolled around temporary supports to form a cylindrical shape.
The engineered vessels had about a two-month storage life before they were implanted in the patients, he said. They have held up in mechanical and animal tests when used more than a year after they were made, he said. The grafts don't appear to trigger a response from the patients' immune systems, eliminating the need for powerful immune suppressing drugs and tests to match the cells used in the graft to the patients' tissue type, he said.
"This version, built from a master donor, is available off the shelf and at a dramatically reduced cost," estimated at $6,000 to $10,000, said Todd McAllister, chief of Cytograft Tissue Engineering Inc., the San Francisco-area company leading the work.
In 2005, Cytograft reported success with its first attempt at dialysis shunts using patients' own skin. Some of the early work was sponsored by the National Heart, Lung and Blood Institute. The new work, using donor cells, makes this advance more practical for wide use ... Cytograft plans a study in Europe and South America comparing 40 patients getting the lab-grown vessels to 20 getting plastic shunts. Studies also are planned on a mesh version for people with poor leg circulation.
You might compare this approach with a range of other strategies, such as the use of bioprinting technologies, or decellularization of donor blood vessels. A range of viable approaches all competing against one another is a sign of a healthy field of human endeavor.