See more of the story

"I can't do this anymore," Sonia Sein told herself, her family and her doctor.

For six years, she had endured a tube inserted in her windpipe, or trachea, to keep her alive, but her discomfort and distress were becoming unbearable.

Largely confined to her New York City apartment, she needed home health aides and had to quit her career. If she talked for more than five minutes, she had to stop "because I couldn't breathe."

The tube was necessary because her trachea — the airway leading to the lungs — had become damaged after she spent weeks on a ventilator for a severe asthma attack in 2014. She had subsequently undergone six major surgeries and more than 10 smaller procedures, but with all conventional approaches to address her condition exhausted, she made plans to have the tube removed and receive only palliative care. "I don't want to live like this," she concluded.

Today, Sein, 56, dances and plays tag with her grandchildren and plans to resume working. She says she feels she has been given a "chance of being alive one more time."

Her transformation follows a groundbreaking procedure she underwent in January: the first time, experts believe, a donor trachea has been successfully transplanted into another person.

The 18-hour procedure, conceived and led by Dr. Eric Genden Sr., chairman of otolaryngology-head and neck surgery at Mount Sinai Health System in New York, is a milestone because — unlike kidneys, hearts and lungs — the trachea has defied decades of transplantation attempts.

Thousands of people in the U.S. develop trachea problems each year from burns, birth defects, tumors and extended intubation. COVID-19 will most likely create more cases.

And hundreds are estimated to die each year because techniques like stents, surgery or lasers cannot heal their damaged tracheas, and they suffocate when airways narrow or collapse.

"There was nothing anybody could do for these patients," said Genden, who developed a transplant approach.

"It's very significant," said Dr. Pierre Delaere, a professor of head and neck surgery at University Hospital Gasthuisberg in Belgium. Still, he cautioned that longer-term results were needed before the technique should be embraced.

The apparent success of Sein's operation is also notable because the trachea field has been rocked for years by a sensational scandal.

That drama began about a decade ago, when Dr. Paolo Macchiarini, working at Sweden's famed Karolinska Institute, garnered headlines and accolades for replacing damaged tracheas with plastic tubes seeded with patients' stem cells. But of 20 patients, including children, most died.

As Macchiarini's work drew criticism, Genden revived his own idea but was uncertain about trying it. The scandal meant "there's an amazing amount of scrutiny," he said.

There was another reason to be daunted, too: historical assumptions that tracheas weren't transplantable.

"The trachea has been characterized as a simple tube, but it's very complex," Delaere said. About 11 centimeters long (just more than 4 ¼ inches), one side curves like a halfpipe, composed of cartilage rings and ligaments. The other side is flat and mobile to move air to the lungs.

Any replacement trachea must be rigid or "it'll collapse like a straw," Genden said. It must be lined with cilia, hairlike projections that move and clean the air we breathe in, he said. And it needs a blood supply to connect to the patient's vascular system.

The "secret sauce" in his approach, he said, is transplanting not just the donor trachea but also its attached esophagus (food tube), thyroid gland and thyroid arteries.

The donor was a young man. The different gender was important, allowing Genden to use chromosomal analysis to detect whether Sein's cells populated the new trachea. As of late March, 6.5% of cells in the donor trachea were hers, with the proportion increasing, he said. He hopes the immunosuppressant drugs, which can create health risks, can be reduced or even stopped "if the entire graft becomes filled with Sonia's cells."

Photographs document Sein's trachea transformation: Her old windpipe looks raw and red, her new one smooth as porcelain.

"I can breathe," she was amazed to discover. "I could feel it in my lungs."