Collapsible valve allows less-invasive heart surgery
June 2, 2008
Written by Jon Van
A collapsible heart valve being tested at two Chicago-area hospitals offers the promise of expanding the kinds of cardiac repairs that may be done without open heart surgery.
The valve can be folded to about the width of a pencil, attached to a catheter and inserted into a patient's body, a procedure akin to a balloon angiography, which forces open narrowed blood vessels. The device is inserted in the heart, where it unfolds to replace a diseased valve, which is then pushed aside.
Cardiologists at Evanston Northwestern Healthcare and Rush University Medical Center are using the new technology as part of two larger tests to determine how well the device works.
Dr. Ted Feldman, a leader of the effort in Evanston, uses the device to treat patients whose aortic valve has become calcified; the average age of these patients is 84. An estimated 100,000 Americans each year suffer aortic valve problems, but only about half undergo surgery to receive valve replacements. While valve replacement can give a patient new vigor and extend life, many older people are poor candidates for open heart surgery.
The transcatheter procedure offers the hope for an alternative, less invasive way to provide the benefits of a new valve, said Feldman. Evanston Northwestern is part of a study involving more than a dozen institutions.
Feldman finds the relatively quick recovery time gratifying: Patients walk out of the hospital a few days after the transcatheter procedure. Patients who undergo open heart surgery typically require months of rehabilitation therapy as part of their recovery.
If the technology consistently performs as expected, Feldman said, it could eliminate the need for open heart surgery among patients who suffer from other ailments.
At Rush, Dr. Ziyad Hijazi has used the transcatheter to replace pulmonary valves for five patients who suffered from pulmonic valve problems, which is a congenital heart disease. These patients tend to be younger, and the condition is less prevalent than aortic valve disease.
Not all patients are eligible for the procedure, Hijazi said. For instance, they must have blood vessels large enough to accept the catheter, which is bigger than those used to open clogged arteries and insert stents.
In addition, inserting the valve is trickier than other catheter procedures and, therefore, requires specific training, Hijazi said.
"Physicians must first train on animals," he said. "The first two or three patients they do should be supervised by an experienced operator."
The idea of using a catheter to install heart valves is not new, said Larry Wood, an executive with Edwards Lifesciences Corp., the California-based firm that makes the new collapsible valves. A Danish cardiologist filed a patent more than a decade ago, he said.
"Most companies in the field were focused on stenting technology," Wood said.
Summer under a microscope: A local company is offering a different kind of summer getaway to interested science teachers and students: microscopy camp.
Westmont-based McCrone Group Inc., a world leader in microanalysis, will offer three summer camps for science teachers and advanced students. While not for everyone, there is growing interest in microanalysis, said Donald Brooks, McCrone's chief executive.
Two pilot camps tested last year convinced the company to expand the program, Brooks said.