For the first time, a patient has been successfully transplanted with an artificial trachea, created from scratch in a lab. The procedure required the coordinated efforts of scientific teams in London, Massachusetts and Stockholm, Sweden, where the windpipe was surgically implanted.
The patient, Andemarian Telesenbet Beyene, a 36-year-old geology student from Eritrea, had been suffering from late-stage tracheal cancer. A rare, aggressive tumor was blocking his windpipe making it hard for him to breath. Diagnosed in 2008, Beyene had failed every conventional treatment including chemotherapy, radiation and surgery. He was running out of time, so rather than wait for a donor trachea for transplantation, his doctors suggested growing his own in the lab.
This is not the first time a lab-engineered trachea has been used for transplantation. But in previous cases, the tracheas were built with donor organs. The donated tracheas were stripped of the donors’ cells — leaving only the cartilage scaffold — and then reseeded with stem cells derived from the recipients’ own bone marrow. Once the stem cells took hold and grew on the scaffold, the tracheas could be transplanted into the patient without fear of rejection.
In Beyene’s case, doctors had to work faster, building a fresh organ, starting with an artificial scaffold in the lab. Reported CNN:
Scientists created a Y-shaped framework for the new trachea, modeling it after the specific shape of the patient’s windpipe. The form was made of polymers that had a spongy and flexible texture. Stiff rings around the tube mimicked the structure of a human trachea.
The form was then bathed in a solution containing the patient’s stem cells “to get the cells to grow on the sponge material,” said David Green, president of Harvard Bioscience. Stem cells can divide and turn into a range of cell types, including those in organs.
The polymer scaffold was made by Alexander Seifalian at University College London. The bioreactor that would hold the trachea and incubate it with Beyene’s stem cells was created by Harvard Bioscience, near Boston. The scaffold and bioreactor were then shipped to Stockholm, where the solution containing the patient’s stem cells was added. The final product was days in the making, versus the months it could have taken to locate a donor organ.
The artificial trachea was transplanted on June 9 in a 12-hour surgery led by Dr. Paolo Macchiarini, a pioneer in engineered trachea transplantation, at the Karolinska University Hospital in Stockholm. The patient appears to have accepted the new organ well, doctors said.
“It’s working like a normal windpipe,” Macchiarini told NPR’s Shots blog. “He’s able to cough. He’s able to expel his secretions. He’s breathing normally. He has the sensation he’s breathing.”
Macchiarini plans several more synthetic trachea implants, two of them involving U.S. patients. One is a 9-month-old infant, adopted from Korea, who was born without a windpipe and breathes through a hole in her esophagus.
In that case, the surgeon will use a biodegradable polymer scaffold that will dissolve over time as it’s replaced with the child’s own cartilage. A non-biodegradable scaffold, like the one Andemarian has, would not grow with the child.
The Stockholm transplant marks another milestone for the field of regenerative medicine. In March, scientists at Wake Forest University reported that they had created artificial urethras in the lab and successfully transplanted them into five boys who had tissue damage.