"He wanted to live, and we didn't want to lose him," said Lewis's wife, Linda, in an interview with NPR. "You never know how much time you have, but it was worth it."
How a Heart Can Have No Beat
Normally, a human heart works on a pump system using the cardiac muscles. There are electrical impulses that tell these muscles to squeeze, pushing blood through each of the heart's four chambers in a coordinated fashion. This squeeze is a “beat” and allows for blood to be circulated through the body efficiently.
However, the system the Dr. Cohn and Dr. Fraiser devised is something entirely different. Rather than using a “pump” mechanism they used a pair of rotors that whirl around and propel blood through the vascular system in one continuous flow. The parts came from two ventricular assist devices that they hooked together.
"Dacron on the inside and fiberglass impregnated in silicone on the outside," said Cohn of the materials they used to create the artificial heart. "There's a moderate amount of homemade stuff on here."
The ventricular assist device used to create this heart is not a new technology. It was created back in the 1980's and has been used effectively for decades in people who have ventricular failure. Vice President Dick Cheany had one implanted just last year. However, this is the first time that two of these devices have been put together to create a fully functional heart.
"I think it's fascinating," said Dr. Jay Pal, assistant professor of cardiothoracic surgery at the University of Texas Health Science Center.
Currently people suffering from total heart failure only have two options: artificial heart or a translplant. However, wait lists for transplants are long and there are very few hearts donated. Artificial hearts, although they have been effective in prolonging lives, also come with problems as well. They function on a pump system which, at 35 million beats per year, tend to wear out quickly.
"A car can [have this type of endurance], but you change the oil and the spark plugs and do the maintenance and they go and go," explained Cohn. "These pulsating hearts work only a year or two, then fall apart." Artificial hearts also have high risks for blood cots and strokes.
The Texas doctors say that this new device is not only much smaller and durable, but the whirling rotors reduce the risk for clots to form.
Although Lewis consented to this device, it remains experimental. After the surgery, Lewis woke up for a short time and was able to speak. However, due to further complications from the amyloidosis, which causes multi-system organ failure, he passed away after 5 weeks with the heart.