Twenty-four children aged between five months and 18 years have received a donor windpipe (trachea) so far, and 16 are now living normally after years of ill-health. Four are still undergoing treatment, and four have died, two from complications after surgery, and two from unrelated causes.
Martin Elliott, a consultant cardiacthoracic surgeon at Great Ormond Street Hospital for Sick Children in London, said the majority of children operated on had a congenital disorder of the windpipe. It was severely narrowed and they found it very difficult to breathe. In some babies, the narrowing was so severe they could not breathe unaided and had to be ventilated from birth.
"Imagine running 100 metres and then breathing through a straw and you will get some idea of how distressing this must be," Mr Elliott said yesterday. "All the children who received the transplant had already undergone reconstructive surgery on their windpipes to alleviate the problem prior to transplantation, but the surgery had failed. Transplantation was their last hope..."
None of the children have suffered rejection of the donor windpipe, or other complications of transplantation, and none required powerful drugs which suppress the immune system and reduce rejection. The surgeons believe this is due to the preserving process applied to the donor trachea before transplantation.
Previous attempts at windpipe transplants had failed, and human tracheal tissue was considered too problematic to work with. But Dr Claus Herberhold and colleagues, from the Kinder Clinic at Bonn University - the only other centre to perform this operation - had perfected a preserving technique for windpipe tissue which appears to destroy its immunogenic properties. They had used it successfully in adults whose windpipe was damaged by injury or disease.
The windpipe tissue is removed from the donor within 24 hours of death, and soaked in formalin for two weeks, then thiomersal for nine weeks, followed by storage in acetone for up to two years.
"We do not need to type tissue and can take it from anyone for anyone using this preserving," Mr Elliott said.
The operation, which takes three to eight hours, depending on the child's condition, involves partial removal of the narrowed segment of the windpipe which is made up of horseshoe-shaped rings of cartilage. About seven-eighths of the ring is removed from the front of the pipe, leaving a small portion at the back.
The donor tissue is then "sculpted" to the appropriate length, and placed over a silastic stent - a special tube which maintains the shape of the graft - which is removed about three months after surgery. It is stitched and glued into place.
During the healing period, a new lining comprised of the child's own cells grows over the graft. Initially, the cells grow haphazardly and a child needs close monitoring to avoid a sudden blockage of the windpipe, but by about four months, a smooth epithelial lining covered in tiny hairs or cilia, which beat to keep the airway clear, is in place.
A portion of adult windpipe in a child of seven to eight will last a lifetime, however, very young babies who undergo the transplant may need another, larger graft as they grow, Mr Elliott said.
Five children have been operated on at Great Ormond Street since 1991, and the remainder in Bonn.
About 50 children a year in the UK and Northern Europe are expected to benefit from the operation, and the results of the pioneering British/German treatment will be presented at the American Association of Thoracic Surgeons, later this month.
Lindsey Desoto, 33, from Lakenheath in Suffolk, whose daughter Sarah, was born with severe narrowing of the windpipe, said yesterday that she had resigned herself to the child's death after various treatments had failed.
"Then she had the transplant at 18 months and has been absolutely fine. She is like any other normal three-year-old and just as happy as her twin, Adam," she said.Reuse content