Tiffany Chisley admits that when Dr. Joshua Kanter first explained what he wanted to do — snake a tube up one of her veins and into her heart and then insert a thumb-size piece of tissue taken from the neck of a cow — she was less than thrilled. He would be using a new technique to address a shortcoming of her troubled heart. The old technique sounded better to her.
“At first, I wanted open heart surgery,” Tiffany said as she sat, prepped for her procedure, at Children’s National Medical Center.
But open heart surgery is no walk in the park. Tiffany, from Brandywine, was born with a collection of congenital heart defects, called tetralogy of Fallot, that necessitated her first open heart surgery when she was barely 1. Her chest was opened three times after that, all when she was a little girl.
Tiffany is 22 now. “I’ve been with Children’s so long, I don’t feel comfortable going anywhere else,” she said.
And eventually she was comfortable with the procedure proposed by Kanter, director of the cardiac catheterization lab at Children’s. It’s called a Melody trans catheter pulmonary valve replacement.
When she was born, some of the vessels around Tiffany’s heart were missing; others sent blood in the wrong direction. Earlier surgery gave her a pulmonary artery — the vessel that takes unoxygenated blood from the heart into the lungs. This graft — slightly bigger than a garden hose in diameter and taken from a cadaver — is called a conduit. Over time, a conduit narrows and will eventually have to be replaced. That will require open heart surgery.
“We want to put that off as long as we can,” said her mother, Jamie Parker. “The older you get, you don’t bounce back as quick.”
Tiffany can buy time by having something slipped inside the old conduit. In the past, that would have been a stent — a tiny metal cage open at both ends that props the conduit open — but a stent lacks a vital piece of anatomy: valves. Those are the thin, flower petal-like pieces of tissue that allow the blood to flow in only one direction, opening with each beat of the heart and then snapping shut to prevent a backwash.
Patients can live for years without valves in their pulmonary arteries, but there are consequences over time. And so: the Melody. “It’s a very simple biologic technology,” Kanter said.
Its manufacturer, Medtronic, takes a segment from the jugular vein of a cow and sews it inside a platinum stent. You and I don’t have valves in our jugular veins, but because they spend much of their lives grazing, cows do. The valves keep the blood from rushing to their heads.
On Friday, with Tiffany anaesthetized in the cath lab, Kanter and his team got to work. He crimped the Melody down so it was about the diameter of a pencil, then loaded it onto the end of a narrow tube. (Valves only work one way, so he was careful to have it pointing in the right direction.)
A wire about the size of a guitar’s bottom E string had already been inserted into the femoral vein in Tiffany’s groin, following the vein all the way through her heart and into one of her lungs. This wire was akin to a monorail that Kanter would follow as he positioned the Melody.
With a steady pressure, Kanter pushed the Melody up the vein, following its progress via monitors that showed Tiffany’s heart in shades of gray. The Melody, resembling a pair of those finger-gripping Chinese handcuffs, was clearly visible as it went into the heart. When Kanter was satisfied with its position, he pushed a pair of syringes that forced saline solution into tiny balloons inside the Melody. The balloons inflated, the Melody popped open and, for a while at least, Tiffany had avoided the pain and potential danger of open heart surgery.
The Melody was approved by the FDA in January 2010. Kanter performed his first Melody valve insertion five months later. Tiffany’s was his 16th.
“It’s really magnificent technology,” he said.
The Melody valve is approved for patients as small as about 30 pounds, which means children are some of its biggest beneficiaries. Tiffany has insurance, but many others aren’t as fortunate. That’s why I ask you to make a tax-deducible donation to Children’s Hospital’s uncompensated care fund. Just go to washingtonpost.com/childrenshospital or send a check or money order (payable to Children’s Hospital) to Washington Post Campaign, P.O. Box 17390, Baltimore, Md. 21297-1390. Donors who give $250 or more will receive a $20 gift certificate to the Chef Geoff family of restaurants.