Bioengineered Windpipe Implanted Into Toddler

A two-and-a-half-year-old girl is the youngest person to have received a bioengineered organ — a windpipe in this case — that was made from plastic fibers and human cells.

The successful transplant of the synthetic windpipe on the girl, a Korean-regenerative medicineCanadian named Hannah Warren, may give regenerative medicine a huge boost. The surgery, which took nine hours at Children’s Hospital of Illinois in April, has occurred only six times. It was the first occurrence in the United States, and received approval from the U.S. Food and Drug Administration (FDA) under rules that allow experimental procedures when the patient has little chance of survival, reports The New York Times.

“Hannah’s transplant has completely changed my thinking about regenerative medicine,” says Dr. Paolo Macchiarini, a surgeon at the Karolinska Institute in Stockholm, who performed the surgery and developed the windpipe. Now that the operation is over, he wants to proceed with clinical trials in the United States that many say are needed to determine how effective these implants are.

Regenerative medicine, also called tissue engineering, creates new tissues and organs when there are transplant shortages, or when there is no other effective cure. Only because there have been recent advances in the understanding of the role that stem cells play in the process has there been any progress.

Until Hannah, the youngest recipient of a bioengineered organ was a 4-year-old spina bifida patient who received a bladder. The New York Times explains further how her windpipe was fashioned:

Dr. Macchiarini’s team made a half-inch diameter tube out of plastic fibers, bathed it in a solution containing stem cells taken from the child’s bone marrow and incubated it in a shoebox-size device called a bioreactor. Doctors are not sure exactly what happens after implantation, but think that the stem cells signal the body to send other cells to the windpipe, which then sort out so the appropriate tissues grow on the inside and outside of the tube. Because the windpipe uses only the child’s own cells, there is no need for drugs to suppress the patient’s immune system to avoid rejection of the implant.

Hannah was born with an extremely rare condition that is eventually fatal in about 99% of cases. Her engineered trachea will probably need to be replaced as she grows, in about four years. Her doctors tried to delay that replacement for as long as they could by making the implant larger than it needed to be now, and including some biodegradable plastic, which may allow it to stretch.

Dr. David Warburton, director of the regenerative medicine program at the Saban Research Institute, who was not involved in Macchiarini’s windpipe development, says he has guarded optimism about these bioengineered tissues. “The challenges will be making a wind pipe that functions better than a temporary fix,” he says.

Source: “Groundbreaking Surgery for Girl Born Without Windpipe,” The New York Times, 4/30/13
Image by OSF Saint Francis Medical Center, Peoria, Illinois.  Jim Carlson, Photographer, used with permission.