“InBreath” Bioreactor with synthetic laryngotracheal scaffold seeded with patient’s own cells (Image: Harvard Bioscience, Inc.)

Surgeons in Russia have successfully transplanted a completely synthetic chunk of the larynx. The operation, which has been performed in two patients, is the first step towards creating an entire synthetic voicebox.

The transplanted synthetic part, about 5 centimetres long, consists of a section of the windpipe, or trachea, at the top of which is a version of the cricoid arch and plate – a hollow, collar-like segment that forms the base of the larynx.

“The cricoid is the most simple part of the larynx to transplant,” says Paolo Macchiarini of the Karolinska Institute in Stockholm, Sweden, and head of the surgical team that performed the operations.


In recent years, Macchiarini, and other groups around the world, have pioneered transplants of veins, tracheas, parts of larynxes and entire larynxes, all of which came from dead donors but were stripped of their native cells and re-coated with the patients’ own to avoid rejection.

The latest graft is different, because it involves a synthetic structure rather than a graft from a cadaver. Before implantation, the part was seeded with stem cells from the patient’s own bone marrow, so that once transplanted it would grow its own layers of native surface cells. The coating was performed in a special reactor by Harvard Bioscience, a company in Holliston, Massachusetts. “We see this as the beginning of growing synthetic organs,” says the company’s president, David Green. “It’s the stuff of scientific fiction becoming medical reality.”

Last year, a man received the first synthetic windpipe, a Y-shaped appendage that was also covered with the patient’s own stem cells.

Ambitious graft

The latest graft is the most ambitious synthetic graft. “This is the most complex synthetic part yet transplanted,” says Macchiarini, head of the surgical team that performed the operations at the Krasnodar Regional Hospital in Krasnodar, Russia, on 19 and 21 June.

The patients – a 34-year-old woman named Julia T and a 28-year-old man called Aleksander Z – are both recovering well, and epithelial cells are already growing on the surfaces of the grafts.

Both were involved in car accidents that left them with damage and blockages in their voiceboxes and windpipes. The woman couldn’t speak at all as a result, and the man could only speak through a voice simulator. After the surgery, both could speak and breathe properly almost immediately. “It was very emotional,” says Macchiarini.

Already, he says, he and his colleagues are working on creating a complete larynx, including the parts that produce sound. “This is one of our research priorities, to build a complete larynx,” says Macchiarini. “I’m hopeful that in the near future we could produce it. We’re working on it and we hope to do the preclinical investigations on it as soon as possible.”

Martin Birchall of University College London says his team is working on development of “half-larynxes” for implantation in patients with partial damage. He says the most promising approach is using material from dead donors that could be stripped of its native cells and re-coated with the patient’s own.

Although his team is also developing synthetic larynxes, he said it would take some time because of the complexity of the moving parts. “We’re at least 10 years away from a full larynx,” he said.