Twenty years ago, few interventional cardiologists could have imagined that during their professional careers it would be possible to replace a diseased aortic valve using catheter-based techniques, rather than open-chest surgery.
Alain Cribier, M.D., was not among the doubters.
Through years of innovation and laboratory testing, Dr. Cribier pioneered the development of the Cribier-Edwards heart valve, a replacement aortic valve composed of biologic tissue sewn onto a stent that can be implanted using standard catheter techniques,albeit with great care and precision. He will describe the development and evolution of percutaneous aortic valve replacement in a keynote Founders Lecture to be delivered at the 30th Annual Scientific Sessions of the Society for Cardiovascular Angiography and Interventions (SCAI), May 9-12, 2007, in Orlando, FL.
"Alain Cribier has been a driving force for catheter-based therapies for valvular heart disease since the mid-1980s. He has brought us to where we are today, with continually evolving technology for aortic valve replacement," said Ted Feldman, M.D., FSCAI, director of the cardiac catheterization laboratory at Evanston Hospital, in Evanston, IL, and a professor of medicine at Northwestern University Medical School in Chicago. "Dr. Cribier has had a remarkable career."
Aortic stenosis most often afflicts the elderly. After years of wear and tear, the valve that serves as a portal between the left ventricle and the aorta becomes calcified, stiff, and narrowed, no longer permitting enough blood to flow from the heart to the rest of the body. Patients typically develop shortness of breath, heart failure, chest pain, and sometimes lightheadedness and fainting.
Surgery to replace the aortic valve is very effective, but it involves opening the chest and requires a lengthy recovery. At least one-third of elderly patients with aortic stenosis are too frail to withstand such major surgery.
With percutaneous aortic valve replacement, a balloon catheter with a stent-mounted valve crimped on its tip is threaded from the femoral artery in the groin into the aorta and across the aortic valve, in a direction opposite,or retrograde,to normal blood flow. The compressed valve is moved into position in the diseased aortic valve and a balloon at the end of the catheter is inflated. The expanded valve pushes aside the diseased leaflets of the patient's own aortic valve and becomes anchored in the valve opening.
The valve can also be implanted through a small incision in the chest and a puncture in the bottom of the left ventricle. This technique is particularly useful in patients with widespread build-up of atherosclerotic plaque, which may make it impossible to pass a catheter through the arteries of the legs and abdomen.
Dr. Cribier, who is chief of cardiology at University Hospital, in Rouen, France, performed the first human percutaneous aortic valve implantation in 2002. Since then, the Cribier-Edwards valve has since been tested in North America and Europe. A multicenter phase 2 randomized controlled trial is expected to begin soon in the United States. Another replacement aortic valve, the self-expanding CoreValve, is also undergoing clinical testing.
"The opportunity for patients to be treated in clinical trials will expand rapidly as the number of these devices grows," Dr. Feldman said. "Catheter-based aortic valve replacement is set to take off."