(Reuters) - Doctors in Sweden have replaced a vital blocked blood vessel in a 10-year-old girl using the first vein grown in a lab from a patient's own stem cells.

The successful transplant operation, reported online in The Lancet medical journal on Thursday, marks a further advance in the search for ways to make new body parts.

It could open the door to stem cell-based grafts for heart bypass and dialysis patients who lack suitable blood vessels for replacement surgery, and the Swedish team said it is now working with an undisclosed company to commercialize the process.

"I'm very optimistic that in the near future we will be able to get both arteries and veins transplanted on a large scale," said Suchitra Sumitran-Holgersson, professor of transplantation biology at the University of Gothenburg, and a member of the team that performed the operation in March 2011.