'HYBRID ORGAN'

After finding a donor, the researchers first depleted the transplanted trachea of the donor's cells and then obtained bone marrow stem cells from Castillo they grew into cartilage cells.

Next, the team seeded these cells on the outside of the donor trachea using a device developed at Milan Polytechnic in Italy that incubated the cells. The researchers used the same device to make epithelial cells to construct the lining of the trachea.

This created a hybrid organ in a lab that Castillo's body would identify as its own and make immunosupressant drugs unnecessary, the researchers said.

Finally, the team grafted a 5 cm (1.97 inch) piece of the trachea onto Castillo's damaged left main bronchus, which connects the main windpipe to the left lung.

Castillo, who lives in Spain, had no complications from the surgery and left the hospital after 10 days. She is returning to normal activities and even called her doctors from a night club to say she had been out dancing all night, the researchers said.

"We believe this success has proved we are on the verge of a new age in surgical care," said Birchall, who predicted the technique could be applied to other hollow organs similar in structure, such as the bowel, bladder and reproductive tract.