Man gets new windpipe with stem cell therapy

By Dr. Ananya Mandal, MDJan 16 2012

Christopher Lyles, 30, of Abingdon, Md, became the first American to undergo an experimental procedure, involving stem cells to treat his trachea cancer. A trachea or windpipe connects the nose and mouth to the lungs, serving a crucial function for life.

Lyles was diagnosed with a rare form of trachea cancer in June last year. As part of his treatment, he underwent seven rounds of chemotherapy and 33 rounds of radiation treatment over the summer. However, trachea cancer is usually resistant to chemotherapy and radiation and his cancer continued to grow. He did not have the option of surgery to remove the tumor because it was too big to be removed. With his tumor, larger than 2 centimeters, Lyles’ breathing was beginning to be jeopardized, and he began to look of other options.

He found that Dr. Macchinarini is conducting experimental treatments. This type of experimental technique can cost between $300,000 and $600,000 and in Lyes case, was not covered by medical insurance.

Since August 2010, Macchiarini and his team had been performing this procedure on patients with tracheal cancer. The original procedure involved doctors harvesting stem cells from two patients’ nose and bone marrow. These two types of cells were grown into two different types of tissue. These tissues would be used to replicate the different types of tissue found on the inner and outer lining of the donor trachea. This study was published in December 2008 in the journal Lancet.

For Lyles’ treatment, his trachea was grown by researchers by taking bone marrow stem cells from Lyles and regenerating them into tissue to create the trachea, biologically identical to Lyles. Paolo Macchiarini, the director of the Advanced Center for Translational Regenerative Medicine at the Karolinska Institute, performed the transplant after removing Christopher Lyles’ trachea. Then the new trachea, made of microfibers of plastic shaped into a windpipe scaffold, was slowly saturated in a bioreactor in a solution of stem cells from Lyles’ own bone marrow.

Macchiarini explained that Lyles’ stem cells could differentiate into the proper type of tracheal cells when placed under the right conditions. Thus when a matrix to create a functioning trachea is surrounded by stem cells, the stem cells can differentiate in the new environment and function with a new role. Using Lyles’ own stem cell reduces the risk of organ transplant rejection from his body.

The operation performed last November lasted 12 hours. Now Lyles can speak, eat, and breath using a trachea developed by his own stem cells in a laboratory. After the procedure, Lyles developed pneumonia, but has recovered now and returned home.

Although this procedure is still being developed, it could lead to improving other demanding transplant needs. Since 2008, Macchiarini had performed 10 trachea implants using patients’ stem cells and windpipes from cadavers. In 2010, he performed the same surgery on the man from Eritrea using a synthetic windpipe, similar to the one used in Lyles.

According to Dr. Mark Iannettoni, head of the department of cardiothoracic surgery at University of Iowa, a trachea is a fragile organ because it is mostly cartilage, which has a poor blood supply. “Once damaged, it is difficult to get it to heal correctly,” said Iannettoni.

“This is a research project and not a proven therapy,” said Dr. Larry Goldstein, director of the stem cell program at University of California San Diego. “There's an important step from innovative therapy to the research needed to bring the innovative therapy to a large number of people.” In fact, Goldstein said there's a lot more information needed to know exactly how the procedure worked.

Macchiarini said this procedure could pave the way for other challenging transplants including the heart valve, chest wall, lungs and the esophagus. “We need to be very cautious and don't make hope for patients with cancer, because this is experimental,” said Macchiarini. “But so far the patients have had incredible results for an untreatable cancer.”