The Ex Vivo Lung

As if finding a lung to put into late stage respitory disease patients wasn't hard enough, about four out of every five lungs donated have to be rejected from use because they don't fit the criteria for a safe transplant. But, if they were allowed to heal themselves they may be able to be more transplantable. The only problem is how do you keep a lung alive when the host has already passed?

Doctors at Toronto General Hospital have solved this problem with the invention of the XVIVO lung perfusion system. This system allows doctors to keep the lung alive for up to 12 hours, and during that time repair the lung or allow it to repair itself. They accomplish this by using a ventilator, filter, and glass dome to protect the lungs. By keeping the lungs at 37 degrees celcius and perfusing it with a bloodless solution carrying nutrients, the function of the lung can be examined to better determine whether it can be transplanted or not.

Four patients have already had successful lung transplants from the XVIVO system, with one previously being declared as unfit for transplant. The recipient was out of the hospital within 12 days.

The XVIVO system brings up a host of new techniques that could be used to prep the lung for transplant, such as immunologically preparing the organ, or modifying it via complex molecular and cellular repair techniques. Normally the lungs are cooled before transplantation to better preserve them. This unfortunately slows down metabolism possibly injuring the lung further. With the XVIVO system they are kept at a constant 37 degrees celcius allowing them to be kept prime and ready for trasplant. This possiblities for this system are endless, and maybe someday we will be able to completely modify the lung immunologically so that the recipient's immune system thinks the new lungs are still the person's own lungs.

http://www.youtube.com/watch?v=gXqMsraSb84
http://singularityhub.com/2009/04/23/donated-lungs-breathing-outside-the-body-video/

Cody Sanderson