In early July, Karolinska University Hospital issued a press release about a successful trachea transplant using synthetic tissue. It got mainstream media coverage and it was interesting, I thought, but evolutionary and not revolutionary. We had covered a Lancet paper on much the same thing in 2008. But in the course of a correspondence with a media rep she noted something important; not only was this not a traditional transplant, this was not even one where an organ was decellularized and recellularized with the patient's stem cells, it was created for the patient and in just two days.
That meant no immunosuppressive drugs, at $20,000 per year, and no morbidities due to their side effects.
To me, it also meant no waiting list for a transplant. Ever.
Forget the operation, I thought, that can excite Reuters and USA Today readers for a day. I wanted to talk about the machine that might make it possible to get people excited about this for the next five years.
So she put me in touch with David Green, President of Harvard Bioscience, the company that made the bioreactor which grew the new trachea. It looks simple, like a box with a scaffold. Heck, it looks like a chicken rotisserie but E=MC^2 looks simple too. The reality is that a lot of complexity goes into a simple box that is able to make a new trachea using a patient's own stem cells. Tissue engineers have been marrying cells to matrices to regrow parts for years but this was a step beyond because no donor organ was needed - and it saved the patient's life.
Looks simple, right? Sure, in the way 2,000 years of all science looks simple. Credit: Harvard Bioscience
The process sounds easy enough, they made a polymer trachea and then they bathed it in stem cells and turned it once a minute. Sounds more and more like that chicken rotisserie, right? More like seeding your lawn at this point - though maybe an FEA mesh is a better analogy for the Science 2.0 audience, since science types don't mow the lawn - the seeded cells grew and formed into the new organ, inside and out. After that the surgery looked routine - to you and me. In reality the entire process was quite intricate.
Courtesy of Harvard Bioscience. Not to be reused without their express permission.
A trachea is a milestone but there are only about 1,800 situations per year where this will help patients. Esophageal cancer occurs 20 times as often and coronary artery bypass grafts occur a million and a half times per year. And then there are the Big 5 in the future - solid organs like the heart, lung, liver, kidney and pancreas. That's the future, that's the excitement.
First would need to come the esophagus on the road map to something like a lung transplant. The esophagus is 10 times as long as the trachea and is muscly, not a hollow tube. That sort of controlled chaos growth is not yet possible, I quickly learned, but it is getting closer.