First virtual implantation of artificial heart

RESEARCHERS from the Arizona State University (ASU) and medical professionals at Phoenix Children’s Hospital have performed what they believe is the first virtual implantation of a pioneering artificial heart, and an implantation of that artificial heart in an undersized adolescent patient.

The actual device was implanted into a 14-year-old boy, one of the smallest pediatric patients to date to receive a total artificial heart (TAH) as a bridge until actual heart transplantation can be performed.

Initially, the TAH – which is normally sized for adults – was implanted into the teen, but complications arose.

ASU engineer David Frakes examines a 3-D print of an optimized, patient-specific artificial heart that was virtually implanted into a 14-year-old boy.

David Frakes, who led the ASU team, has been working with technology developed by the Tucson-based company SynCardia Systems Inc., which has developed the TAH for adult patients with end-stage biventricular heart failure who are waiting for a permanent heart transplant.

ASU engineer Frakes, an assistant professor in the School of Biological and Health Systems Engineering and the School of Electrical, Computer and Energy Engineering, two of the university’s Ira A. Fulton Schools of Engineering, He also used advanced software developed by the Belgium-based company Materialise to generate 3-D reconstructions of cardiovascular, respiratory and skeletal structures that provide a virtual screening of pediatric patients that helps ensure a proper fit of the artificial heart in the patients.

Professor Frakes, using these technologies, aided a Phoenix Children’s Hospital team to map procedures for the first-ever virtual implantation of the Total Artificial Heart. Images were obtained at the hospital, and an accurate 3-D model was made by engineers at ASU. The 3-D data set helped reveal the reason for the complication, allowing the team to create virtual implantations for small patients who will need the Total Artificial Heart in the future.

His team performed the virtual implantation of the heart in the patient using Materialise’s Mimics Innovation Suite’s diagnostic technology to create a 3-D reconstruction of the adolescent’s chest cavity from a computerized tomography (CT) scan, and then used a laser scan of the TAH to virtually place the heart into the chest cavity.

Professor Frakes documented Phoenix Children Hospital’s experience in a recent edition of the medical journal Perfusion (see an abstract of the research paper).

After the implantation, a clinical review and a series of measurements – called a virtual fit analysis – determined whether the TAH could properly fit into the boy’s chest cavity. Phoenix Children’s Hospital has adopted this procedure for use with all future TAH candidates.

The artificial heart supported the boy for 11 days before he underwent a heart transplant.

“This cutting-edge technology helps medical interventionists and surgeons plan complex procedures,” explained physician Stephen Pophal, chief of cardiology at Phoenix Children’s Hospital. “With the help of the bioengineers at ASU, we can see if devices designed for adults can fit in children. This is especially important as a newer and smaller version of the TAH is awaiting Food and Drug Administration approval and promises to benefit many children with severe heart disease.”

While the TAH isn’t a long-term solution, it keeps patients stable until a heart for transplant is available and increase quality of life during the waiting time.

“Virtual implantations can help bridge the gap between heart failure and transplant in congenital patients of all ages,” Professor Frakes said. “They can help optimize a proper fit during pre-operative planning so that complications are minimized by orienting the device in the chest cavity correctly.”

Virtual implants and fit analyses will help to show compatibility on a case-by-case basis. “Many patients may be labeled too small for the device, based on standard criteria, when their body may actually accept it,” he said.

SynCardia has a smaller TAH in development that is designed for patients of smaller stature. But with the current model, implantation into such patients could be risky without the pre-operative virtual implant.Firefly