EurekAlert! look at tissue engineering and the heart: "Some day, heart attack survivors might have a patch of laboratory-grown muscle placed in their heart, to replace areas that died during their attack. Children born with defective heart valves might get new ones that can grow in place, rather than being replaced every few years. And people with clogged or weak blood vessels might get a new 'natural' replacement, instead of a factory-made one. These possibilities are all within reach, and could transform the way heart care is delivered ... Technology has advanced so much in recent years [that] scientists are closer than ever to 'bioengineering' entire areas of the heart, as well as heart valves and major blood vessels. ... Although there remain tremendous technological challenges, we are now at a point where we can engineer first-generation prototypes of all cardiovascular structures: heart muscle, tri-leaflet valves, blood vessels, cell-based cardiac pumps and tissue engineered ventricles." It won't be too many years now until the simpler organs can be rebuilt from your own stem cells.