A 10-year-old British boy has become the first child to undergo a windpipe transplant with an organ crafted from his own stem cells. It is hoped that using the boy's own tissue in the nine-hour operation at Great Ormond Street Hospital will cut the risk of rejection. The world's first tissue-engineered windpipe transplant was done in Spain in 2008 but with a shorter graft. Doctors say the boy is doing well and breathing normally.