Doctors for the first time have successfully used an artificial lung system to keep alive a patient without lungs for 48 hours.
The patient had influenza that progressed to lung failure, with the infection rapidly destroying his lungs. He needed to have them removed but was too sick to undergo transplant surgery, explained Dr. Ankit Bharat of Northwestern Medicine in Chicago, who led the team caring for the patient.
To remove the lungs without replacing them, two major problems had to be solved, Bharat said.
"Think of the lungs as a giant sponge that the heart pushes blood through," he said. "This sponge acts like a shock absorber. When you remove the lungs, you remove that cushion."
"Suddenly, the right side of the heart is pumping against clamped vessels - like pumping against a brick wall - which causes it to stretch and fail."
In addition, the right side of the heart pumps blood to the lungs, which in turn send freshly oxygenated blood back to the left side of the heart. If you remove the lungs, the left side of the heart sits idle because no blood is coming to it, the heart muscle shrinks, and the valves stick shut with blood clots.
In the journal Med, Bharat's team describes how their total artificial lung system used tubes, or shunts, to solve both problems.
"Our system is a new design specifically engineered to maintain normal heart physiology without the lungs," Bharat said.
One day after the destroyed lungs were removed, the patient "started to get better because the infection was gone," Bharat said.
Over the next 48 hours, the patient improved enough to undergo a double-lung transplant. More than two years later, he has returned to daily life with excellent lung function.
"Because it was successful... it provides a blueprint for saving others," Bharat said.
