Tiny pump shrinks heart surgery

NASHVILLE -- A pump the size of a golf ball is giving heart failure patients a second chance at life with lower odds of surgical complications.

It's called the HeartWare HVAD, and a Vanderbilt University professor is teaching surgeons from across the country how to implant it through a small incision on the side of the chest. That's a radical departure from an earlier generation of heart pumps, which required cutting through the sternum and the abdomen.

Dr. Simon Maltais, a professor of cardiac surgery, traveled to Germany where he learned the procedure at the University Heart Center in Leipzig from two physicians, who are considered pioneers in the minimally invasive technique.

Maltais has implanted 50 of the devices. He has been able to do this through a small incision in 40 percent of those surgeries. The minimally invasive surgery is at this point considered an "off-label" approach, but he is part of a group planning a clinical study to test its safety and effectiveness.

"We try to minimize splitting the sternum, which can be very traumatic," Maltais said. "This facilitates the reoperation for the eventual heart transplant. It's a a very big advantage."

Ventricular assist devices are intended to be stopgap measures until patients can get heart transplants. But some patients rely on an earlier version to be a permanent option because of the divide between donor hearts and the people who need transplants.

In 2010, the U.S. Food and Drug Administration approved permanent use of the HeartMate II — the brand name for the left ventricular assist device primarily used in this country. The HeartMate II is a larger device — about the size of a softball and roughly four times as big as the HVAD. The HVAD is not yet approved for permanent use.

Both devices take over the work of the left ventricle, which pumps oxygen-rich blood into the aorta and throughout the body. The rest of the heart, the right side, still does its own work of circulating blood to the lungs.

However, the smaller size of the HVAD can allow two of them to be implanted when the right ventricle is also failing, said Dr. Mary Keebler, a Vanderbilt cardiologist.

Both the HVAD and the HeartMate II require people to wear external control units, which can be carried over the shoulder or worn around the waist. They are powered by external batteries. A drive line goes from the pump to the abdomen, where it exits for battery connection. Although the batteries can last half a day or longer, people with the pumps carry extra batteries wherever they go.