"Yale Surgeons Use Engineered Vessel to Treat Child's Heart Defect"

For the first time in America doctors have engineered a "living vascular graft" which was implanted in a child who was born with a single-ventricle heart defect (Medicine at Yale).  Unlike former methods in which synthetic grafts were used, this engineered graft can grow as the child develops.  Thus, this growth ability of the engineered vessel erases the need for "risky repeat operations" to replace the graft (as was previously done with synthetic grafts) as the child grows.  

In engineering the blood vessel, Toshiharu Shinoka and Christopher Breuer used bone marrow cells to "bathe biodegradable scaffolds shaped like heart valves" (Medicine at Yale).  When these grafts were implanted in the body, the bone-marrow cells sent out signals indicating inflammation of the vessel, causing other blood cells to surround the graft and undergo vein regeneration.  Breuer stated, "'we can actually induce the body to regenerate a blood vessel or grow a blood vessel, just like a salamander can regrow its tail or a starfish can regrow one of its arms'" (Medicine at Yale).  Currently, this new technology has only been used in a "low-pressure area of the heart."  However, with further research engineered vessels may one day be used to treat various forms of congenital heart disease, saving hundreds of children's lives.

http://www.medicineatyale.org/v7i4_sep_oct_2011/breuer.html