Best of 2013
Advancing Ventricular Assist Devices
Seattle Children’s is in the vanguard of using mechanical circulatory support to give kids and teens with advanced heart failure the best quality of life.
In July 2013, Seattle Children’s Heart Center implanted a Thoratec HeartMate II ventricular assist device (VAD) into a 16-year-old, discharged the patient while he waited for a new heart, and then performed a transplant five weeks later.
The successful implantation of the palm-sized device marked the first time a patient at Children’s — or any pediatric hospital in the United Network for Organ Sharing (UNOS) Region 6 (Washington, Oregon, Montana, Idaho, Alaska, Hawaii) — received a HeartMate II and was bridged to transplant outside the confines of a hospital.
“Teens who are able to live a relatively normal life prior to transplant have better outcomes after transplant,” says Dr. Sabrina Law, lead VAD cardiologist at Children’s. “Being in a hospital bed tethered to a machine for weeks or months is incredibly hard on the body and mind. VADs give patients the freedom to stay active.”
Different technologies, similar skills
Children’s Heart Center is one of an elite group of centers with the expertise to implant adult-sized VADs like the HeartMate II into teens, either as a bridge to transplant or as a therapeutic tool to allow the heart muscle to rest and recover from injury.
Over the last seven years, the Heart Center has performed 14 successful implants — procedures made possible because of the substantial amount of information available on VADs in adults and because of the center’s ongoing designation as a center of excellence in extracorporeal life support (ECLS).
“The team at Children’s has spent years troubleshooting heart-lung bypass systems, and that’s the same think-outside-the-box mindset you need to fine-tune a VAD,” explains Dr. Jonathan Chen, who joined Children’s as surgical director of the Heart Center in 2013 from Columbia University Medical Center, which has one of the largest VAD programs in the nation. “We’re expanding from ECLS technology to that of VADs; both require similar expertise across every cardiology subspecialty.”
Children’s ECLS leadership includes Drs. Mike McMullan and Tom Brogan, who are members of the international steering committee for the Extracorporeal Life Support Organization (ELSO) — a worldwide consortium that develops and evaluates novel therapies for failing hearts and other organs. The two publish extensively in the field.
Children’s Heart Center also offers one of the few pediatric ECLS fellowships in the U.S. Current fellow Dr. Andy Mesher is finishing a project to build an ECLS simulator to practice cannula insertion that is much less expensive than current simulators, which cost about $500 per use; Mesher’s pencils out to $5 per use.
Breaking new ground
Although there are now many mechanical pump options for teens with chest cavities big enough to fit an adult-sized device, VADs for smaller children and infants are still very new.
Children’s recently was chosen as one of two sites on the West Coast to test new mechanical heart-assist devices for a trial sponsored by the National Institute of Health’s National Heart, Lung, and Blood Institute (NHLBI). McMullan, director of mechanical cardiac support and ECLS, and Law will lead Children’s part of the “Pumps for Kids, Infants, and Neonates (PumpKIN)” study, which is slated to begin in fall 2014 and will focus on finding the best device for infants and young children who weigh as little as 7 pounds.
The Heart Center team is also one of the first centers in the nation to be authorized to use the new SynCardia Total Artificial Heart — an implantable mechanical replacement heart made in different pediatric sizes and used to bridge patients to transplant when both ventricles of the heart are failing to pump enough blood to the body. (Most VADs that support both sides of the heart sit outside the body on top of the abdomen, and patients who have them cannot be discharged home.)
“Not many pediatric heart centers have the complete team and depth of expertise to offer every type of therapy for heart failure,” says Chen. “We’re proud to be the only pediatric heart center in UNOS Region 6 to offer so many options, including VAD technology, to give our families the greatest amount of hope for a healthy child and our patients the best quality of life.”
“Our team's leadership in extracorporeal life support makes us a key player in the emerging field of ventricular assist devices for the tiniest hearts.”
– Dr. Jonathan Chen