Other experts hail the Toronto technique but caution that more work is needed on how to fix lungs, stop the inflammatory response in grafting, and improve mortality in transplant patients.

"The Toronto system seems to re-create normal lung function outside the body," says Jacques-Pierre Fontaine of Brown University's cardiothoracic-surgery division. "If we can keep the organ outside the body longer with minimal ischemic damage, we can go farther to get a lung." However, says Fontaine, "the real test" will be how well the patients do with the transplanted lungs. "Proof will be in the survival data."

Joshua Sonnet, director of lung transplant at Columbia University Medical Center, agrees that the Toronto system is an improvement that brings existing technology to the next level, where it can act as a springboard to wider use. "We have two major problems: an organ shortage--and this [Toronto] system helps with that immediately, if we can start to recondition some lungs. More importantly, the other problem is having those organs last a long time. Mostly, they don't last because of chronic rejection and the side effects of medicines we use to keep them from getting rejected. So as we're able to manipulate these organs out of the donor body, we're able to do things and improve them so not only do they work immediately better and can [they] be transplanted, but, even more exciting, they work."