Tuesday, April 30, 2013

Two-Year-Old Girl Gets Life-Saving Trachea Transplant Made From Her Own Stem Cells

An amazing story at today's New York Times, "Groundbreaking Surgery for Girl Born Without Windpipe":
PEORIA, Ill. — Using plastic fibers and human cells, doctors have built and implanted a windpipe in a 2 ½-year-old girl — the youngest person ever to receive a bioengineered organ.

The surgery, which took place on April 9 here at Children’s Hospital of Illinois and will be formally announced Tuesday, is only the sixth of its kind and the first to be performed in the United States. It was approved by the Food and Drug Administration under rules that allow experimental procedures when otherwise the patient has little hope of survival.

Dr. Paolo Macchiarini, a specialist in the field of regenerative medicine who developed the windpipe and led the complex nine-hour operation, said the treatment of the Korean-Canadian toddler, Hannah Warren, made him realize that this approach to building organs may work best with children, by harnessing their natural ability to grow and heal.

“Hannah’s transplant has completely changed my thinking about regenerative medicine,” said Dr. Macchiarini, a surgeon at the Karolinska Institute in Stockholm. He said he would like to proceed with a clinical trial in the United States, something that critics of his approach have called for.

Hannah was born without a windpipe, or trachea — an extremely rare condition that is eventually fatal in 99 percent of cases — and had lived since birth in a newborn intensive care unit in a Korean hospital, breathing through a tube inserted in her mouth. Because of other developmental problems, she cannot eat normally and cannot speak.

Nearly three weeks after the surgery, the girl is acting playfully with her doctors and nurses, at one point smiling and waving goodbye to a group of visitors. Dr. Mark Holterman, a pediatric surgeon at the hospital, said that Hannah was breathing largely on her own, although through a hole in her neck, not through her mouth yet. “She’s doing well,” he said. “She had some complications from the surgery, but the trachea itself is doing great.”

Dr. Macchiarini described a look of befuddlement on the child’s face when she realized that the mouth tube was gone and she could put her lips together for the first time. “It was beautiful,” he said.

The goal of regenerative medicine, or tissue engineering, is to create or regrow tissues and organs to ease transplant shortages or treat conditions that do not have an effective cure. After years of scant progress, tissue engineers have begun to make advances as they have gained a better understanding of the role that stem cells — basic cells that can become tissue-specific ones — play in signaling the body to grow and repair itself...

To make Hannah’s windpipe, 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.
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