First U.S. trans-catheter replacement of a pulmonary valve performed at University of Chicago Comer Children's Hospital
December 15, 2005
On December 13, 2005, a team led by Ziyad Hijazi, MD, the George M. Eisenberg Professor of Pediatrics and chief of pediatric cardiology at the University of Chicago, performed the first trans-catheter pulmonary-valve replacement in the United States. The patient was Justin Reaves, a 16-year-old boy who urgently needed the procedure, but who was not a candidate for open-heart surgery and conventional heart valve replacement.
The three-hour minimally invasive procedure went smoothly. Reaves recovered well, was discharged from the University of Chicago Comer Children's Hospital the next day, and he and his parents began their drive home, to the family farm in South Dakota, that afternoon.
Surgically replacing a leaky or damaged heart valve is a complicated but not uncommon procedure. For patients, such as Reaves, who have undergone multiple previous cardiac surgeries, however, the risks increase substantially because scar tissue at the incision site and around the heart can make access extremely difficult and impair healing.
Earlier this year, clinical trials began in the United States to determine whether delivery and placement of a replacement heart valve through a catheter, inserted into a blood vessel in the groin and snaked up into the heart, can serve as an alternative to open-heart surgery for patients at extremely high risk.
The U.S. feasibility trial, using the Cribier-Edwards percutaneous heart valve produced by Edwards Lifesciences (NYSE:EW), is focused only on replacement of the aortic valve, but Hijazi's team and Edwards were able to get special "compassionate-use" permission from the U.S. Food and Drug Administration to use the device in this unusual case.
Officials from Edwards stress that this was an unusual, compassionate-use exception, and that there are no plans for an ongoing pulmonary trial.
Justin Reaves has a life-long history of heart trouble. He was born with aortic stenosis, a narrowing of the aortic valve, which ensures that blood flows only one way, out of the left ventricle and into the aorta, when the heart beats. He underwent valvuloplasty, the use of an expandable balloon to open the narrowing, once at 18 months and again at age five.
That kept him going until he turned 14, when his constricted and leaky aortic valve finally had to be replaced. This time he came to the University of Chicago, where surgeons performed a Ross procedure, in which they removed the pulmonary valve and used it to replace the aortic valve. Then they replaced the pulmonary valve with a valve from a cadaver.
Unfortunately, Justin had post-operative complications, including an infection around the surgical incision, that required several trips back to the operating room, and both valves were again replaced.
By the summer of 2004, however, he had developed a new narrowing, this time in his transplanted pulmonary valve. The problem got worse over time until by this fall he was so short of breath that "he even got tired just talking," said his mother, Jeanine Reaves.
Because of all his previous heart operations, the team searched for any possible alternative to more surgery for Justin. Hijazi, an authority on non-surgical repair of cardiac defects, was able to work with Edwards Lifesciences to help convince the FDA that replacing the valve in this way was a reasonable option and to perform this one case.
Designed for use through a catheter, the Cribier-Edwards valve can be inserted and placed in a beating heart without surgery or reliance on cardiopulmonary bypass. The device integrates a balloon-expandable, wire-mesh, stainless-steel stent that serves to anchor it in place, with tissue leaflets, that ensure one-way blood flow.
The balloon-mounted valve is compressed to the diameter of a pencil, then inserted at the tip of a long thin plastic catheter through a small incision in the groin and delivered through the veins to the heart. The catheter is passed through the right atrium to the right ventricle, which pumps blood to the lung through the pulmonary valve.
In Justin Reaves' case, once physicians reached the pulmonary valve, they used the balloon to expand the stent inside the existing valve. This opened the narrowed valve and lodged the device--now about as wide as a quarter--in place without the need for sutures.
While traditional valve-replacement surgery requires opening the patient's chest, stopping his or her heart, and maintaining circulation with cardiopulmonary bypass, this procedure was completed on a beating heart without the use of a heart-lung machine. Reaves was awake and alert within a few minutes after the procedure and talking with his parents and nurses.
"Mom," he said when he woke up, "I can actually take a deep breath." His mother noted that his hands and fingers were "pink, actually pink," right after the procedure, instead of their customary pale gray.
More than 75 patients have received an aortic heart valve as part of feasibility studies taking place in the U.S. and Europe on the Cribier-Edwards valve delivered through the patient's circulatory system via a catheter, but this is the first U.S. case involving the technology for pulmonary valve replacement.
"Ongoing trials will tell us what we can expect in the long term from this percutaneous approach for replacing aortic valves," Hijazi said. "The jury is still out. We don't expect this to be a substitute for traditional surgical valve replacement in most cases. But, for now, we appear to have fixed Justin's immediate problem," he added. "We bought him some time, maybe several years, and who knows what new options we will have by then."
Dr. Hijazi has a personal consulting relationship with Edwards Lifesciences in which he assists the company in testing and developing devices in pre-clinical studies.
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