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Aorta Grafts to Replace Windpipe Breakthrough
A significant medical advance has been made in treating throat disease.
Aortas harvested from human donors have been successfully grafted onto the windpipes of a dozen patients to replace tracheas or surrounding tissues afflicted with lesions or cancerous growths.
The man behind the breakthrough is Dr. Emmanuel Martinod, a surgeon at Avicenne Hospital AP-HP, part of the network of 39 university hospitals serving Paris. His study was recently published in JAMA, the Journal of the American Medical Association.
The publication is the culmination of 20 years of research. In an interview with MedicalExpo e-magazine, Dr. Martinod said he had explored “all the options” before deciding on this procedure, which involves grafting an aorta, the human body’s largest artery that pumps blood from the heart. He said:
Because the aorta is flexible and strong, we could adapt it to align with the correct dimensions of the trachea or bronchus, which is a bit smaller. We used donor bank aortas preserved by freezing them at minus 80 degrees.
Twenty patients with diseases of the trachea, bronchus or carina (the area where the trachea splits into two bronchi) were selected for the study, of which thirteen underwent the graft from 2009-2017. The other patients were treated using conventional methods. Twelve of the thirteen patients who received the graft survived at least ninety days; ten were still living when the study was published. The study demonstrated “feasibility for complex tracheal and bronchial reconstruction,” while “further research is needed to assess efficacy and safety,” the JAMA article indicates.
Dr. Emmanuel Martinod (Courtesy of Christophe Simon AFP)As part of the procedure, a metallic trellis stent was inserted inside the aortic graft to prevent it from closing up. After the operation, the patients’ own cartilage began to grow around the aortic graft, further buttressing it. “Once the cartilage has regenerated and is functional, we can remove the stent within an average of 18.2 months. So you get a solution that is 100 percent biologic,” said Martinod. The patients’ immune systems accepted the graft without complications. “We see few reactions of rejection with this kind of tissue. Sometimes there was inflammation but that may have been due to the reparation surgery, not the graft,” he said.
Procedure First Tested on Sheep
According to an editorial article in JAMA, the Martinod study “is an excellent example of high-quality bench-to-bedside research.” Previous efforts to perform aortic grafts had produced disappointing results. An Italian surgeon, Paolo Macchiarini, performed procedures on eight patients between 2011 and 2014 involving the insertion of artificial tubes seeded with patient stem cells but seven of the patients died of complications. Martinod’s study “is in marked contrast” to the Macchiarini study, which was later found to be fraudulent, JAMA says.
Dr. Martinod tested the procedure on sheep in a laboratory prior to operating on patients. He said:
When we were doing transplants on the model, we noticed that the epithelium [the windpipe’s protective, lubricating lining] started to regenerate and cartilage to form. That was a surprise. This regeneration took a bit longer in the patients than the laboratory models.
Given the procedure’s success, an increase in demand for it can be expected. Apart from the 95 percent survival rate, it offers additional advantages over the existing, widely-used procedure for treating trachea diseases, a tracheotomy, where a hole is surgically created in a person’s neck through which they breathe. “The aortic graft solution gives you a better quality of life. Also, in the case of certain cancers, it is part of the overall cure,” said Martinod.
