One of the first uses of silicone in a medical implant came in the form of lifesaving tubes implanted into young children to funnel excess fluid from the brain into the chest cavity, where the fluid could be safely metabolized and excreted. Since these "shunts" were first used, in the late 1950s, silicone in various forms has come to be an important part of many implants. "It is used in tracheotomy tubes, in artificial lenses for the eye, in artificial heart valves and in facial implants for birth defects or re-constructive surgery after canc ....