Mike C
Well-known member
Still a very long way to go but...
04/03/2006
Researchers in the United States, Canada, and Europe are studying percutaneous valve replacement as a potentially less-invasive alternative to open-heart procedures that could allow patients to recover in as little as two weeks, compared with the two to three months generally required for traditional valve replacement surgeries, the Associated Press reports. Roughly 225,000 patients per year undergo cardiac valve replacement surgery, in which a surgeon ?saws the breastbone in half, stops the heart, cuts out the old valve, and sew in a new one.? For the percutaneous procedure?which currently is available at only a few U.S. hospitals and is performed only in patients who are too sick to undergo open-heart procedures?surgeons do not remove the diseased valve but rather ?prop it open and wedge an artificial one into the rigid doorway? without stopping the heart. Cardiologists at Royal Oak, Mich.-based William Beaumont Hospital, the Ohio-based Cleveland Clinic, and New York City-based New York-Presbyterian Hospital are involved in a U.S. trial of a ?collapsible valve made of animal tissue that is folded inside a stent? that is manufactured by Edwards LifeSciences and is typically inserted through an artery in the leg. When the device is nearly in place, physicians ?speed the heartbeat until normal pumping pauses for mere seconds?and quickly push the new valve inside the old one.? A balloon is then inflated to widen the stent and ?lodge it into place? to resume blood flow. To date, 19 U.S. patients and more than 80 patients worldwide have received the device, including 14 patients in Canada, Germany, and Austria who had the valve inserted via an incision between the ribs, a method that provides ?a more direct route to the heart for patients whose leg arteries are too clogged.? In addition, other researchers in Canada and Europe are testing a valve made by CoreValve that is made of pig tissue and uses a ?self-expanding stent? that is threaded through a leg artery and does not require a balloon for insertion. The company says it hopes to begin U.S. trials of the valve next year, and a German researcher says he plans within the next several months to begin trials of a newer version of the valve that is small enough to be inserted via an artery near the collarbone. Despite the initially promising results of percutaneous valve replacement, experts warn the procedure can pose serious risks. For example, Edwards LifeSciences last year temporarily halted the U.S. trial of its valve after four of the first seven patients died; physicians had been inserting the valves through a vein in the leg, not an artery, requiring ?tortuous turns inside the heart? and sometimes causing damage to other valves. In addition, the first four patients to receive CoreValve?s device ?died as [physicians] struggled to develop and learn the through-the-artery technique.? A valve specialist at Northwestern University who is monitoring the research for the American Heart Association says the procedure involves ?lots of technical challenges that need to be overcome? before it can be widely adopted (AP/Baltimore Sun, 3/2).
04/03/2006
Researchers in the United States, Canada, and Europe are studying percutaneous valve replacement as a potentially less-invasive alternative to open-heart procedures that could allow patients to recover in as little as two weeks, compared with the two to three months generally required for traditional valve replacement surgeries, the Associated Press reports. Roughly 225,000 patients per year undergo cardiac valve replacement surgery, in which a surgeon ?saws the breastbone in half, stops the heart, cuts out the old valve, and sew
