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 transplant, reported online in The Lancet medical journal yesterday, 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 was now working with an undisclosed company to commercialise 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, a professor of transplantation and a member of the team that performed the operation in March last year. The advantage of using tissue grown from a patient's own cells is there is no risk of organ rejection and hence no need for lifelong immunosuppressive drugs.

The breakthrough involved a 10-year-old girl with an obstructed hepatic portal vein, which drains blood from the intestines and spleen to the liver. Its blockage can be fatal.

The team from the University of Gothenburg took a 9cm section of groin vein from a deceased donor and removed all the living cells, leaving just a protein scaffold tube. Stem cells extracted from the girl's bone marrow were injected onto the tube. Two weeks later the graft was implanted.

The new blood vessel restored normal blood flow, although after a year it narrowed and a second stem cell-based graft was needed.