Each year, about 1.5 million people in the U.S. suffer from aortic valve stenosis, a narrowing of the heart's aortic valve that can lead to a heart attack. In severe cases, doctors perform open-heart surgery to replace the valve, but many patients are too frail to undergo such a procedure; fifty percent of those who don't get surgery die within two years.
The Sapien Transcatheter Heart Valve, which unlike other replacements can be inserted through an artery, should make it possible to give a new valve to many people who were previously ineligible. The Sapien consists of flaps of cow tissue sewn onto a metal frame. It can collapse from a diameter of about an inch to that of a pencil—thin enough to fit through the femoral artery.
Once the valve is in the right location, doctors push it open with a balloon. The mesh then holds the device in place, while the flaps prevent blood from flowing in the wrong direction. In trials, patients who received the valve were 40 percent more likely to be alive a year later.
23 or 26 mm
: 2.0 or 2.6 ounces