A surgical innovation called partial heart transplantation could transform the care of children with severe heart valve disease and enable thousands of additional valve transplants each year, according to a presentation given today by Joseph Turek, MD, at the 46th Annual Meeting and Scientific Sessions of the International Society for Heart and Lung Transplantation (ISHLT).
“The partial heart has arrived,” said Dr. Turek, a pediatric heart transplant surgeon at Duke University. “This is realistic, reproducible, and transforms what we can offer our patients.”
Ailing heart gives hope to other patients
Unlike a heart transplant, a partial heart transplant only replaces the defective valve and related structures. Every year, more than 330,000 children around the world require intervention due to malfunctioning heart valves due to congenital defects. Because the prosthetic valve does not grow as the child grows, these patients often undergo multiple high-risk valve replacement surgeries before reaching adulthood.
Dr. Turek calls this procedure a “domino effect” of traditional heart transplants. Diseased hearts that are removed and replaced due to problems with the muscles, coronary arteries, or congenital defects often have structurally normal valves that can be transplanted into another patient.
“We perform approximately 5,000 heart transplants each year in the United States,” Dr. Turek said.
These hearts alone could theoretically yield two “domino” valves per patient. Even accounting for unusable valves, this could equate to several thousand valve transplants per year in the United States. ”
Joseph Turek, Duke University
Partial heart transplant benefits the youngest patients
He noted that demand for the valve far exceeds demand for Full Heart, making this increased availability particularly important. For patients, the implanted pediatric valve tissue grows with the child, eliminating the need for repeated replacements.
Dr. Turek also discussed further advances that will expand the donor pool and reduce rejection in transplant recipients.
- Simultaneous heart and thymus transplantation to induce immune tolerance
- Circulatory post-death donation (DCD) and “bench resuscitation”
- Preclinical xenotransplantation using genetically modified pigs.
The simultaneous heart and thymus transplant is based on a technique developed at Duke University that uses cultured thymus tissue to reconstitute the patient’s immune system. For children with T-cell deficiency who require heart transplantation, combined heart and thymus transplantation allows for the use of very low doses of immunosuppressive drugs.
“We are actively researching this, and the hope is that we can reduce or eliminate the need for immunosuppressive therapy and potentially extend graft survival,” he said.
New innovation gives hope to young heart patients
Duke University, like other transplant centers, also performs pediatric DCD heart transplants, and recently introduced “on-table resuscitation,” in which the heart is removed and briefly resuscitated on a back-table circuit to assess function.
Dr. Turek concluded the session by discussing early-stage xenotransplantation research in animal models and highlighting the long-term vision for overcoming organ shortages.
“Some of these technologies are still in their infancy,” Dr. Turek said. “But partial heart transplants are already happening and poised to benefit far more patients who need valves than those who need a whole heart.”
ISHLT’s annual general meeting and academic sessions will be held from April 22nd to 25th at the Metro Toronto Convention Center in Toronto, Ontario, Canada.
sauce:
International Heart and Lung Transplant Society
