March 31, 2022
Mayo Clinic Children's Center pediatric cardiologists and heart surgeons are using a new, less invasive approach to regulate blood flow to the lungs of their youngest patients with congenital heart disease.
The procedure, called endovascular band placement, reduces pulmonary over-circulation with a pulmonary flow regulator, allowing very young patients to grow prior to cardiac repair. This procedure was developed to replace the pulmonary artery band procedure, in which surgeons perform a sternotomy to place a tie around the pulmonary artery, decreasing the diameter of the blood vessel to limit the amount of flow that can enter that vessel.
Device adapted for infants
A pulmonary flow regulator is a modification of a small device designed to seal off blood flow through an artery or a vein. The device has an expanded polytetrafluoroethylene (ePTFE) covering that is designed to block all flow immediately on implanting.
"We create a small hole in the occlusive ePTFE that results in a fixed diameter opening that can regulate how much blood flow goes through the device to the vessels beyond," says Jason H. Anderson, M.D., Pediatric Cardiology, Mayo Clinic in Rochester, Minnesota. "Our patients are under mild sedation at the time of implantation, allowing the band to be safely placed and assessed in real time, under normal physiological conditions."
The device is placed via a catheter. If adjustments are needed, the device can be removed, modified, and reimplanted during the procedure. "The patient receives immediate benefit without the need for a postoperative recovery," says Dr. Anderson. Mayo Clinic has enhanced the approach for endovascular band placement for infants and is one of the first U.S. medical centers to offer this procedure to multiple patients with many forms of congenital heart disease.
Benefits of endovascular banding procedure
Many forms of congenital heart disease result in excessive blood flow to the lungs. This extra blood flow can result in rapid heart failure, pulmonary edema, and a stealing of blood flow from other areas including the brain, gut and kidneys. Infants with these conditions often require respiratory support and are unable to feed due to an increased risk of necrotizing enterocolitis, delaying normal progress and development. Most often, these conditions require an infant to undergo an operation within days or weeks of birth. Options are:
- A complex complete cardiac repair performed earlier than ideal because of the pulmonary over-circulation
- A surgical "palliation" called pulmonary artery banding, which decreases pulmonary artery blood flow
The endovascular banding procedure can be a better option for select patients. It allows for the extra blood flow to be regulated, ensuring just enough flow goes to the lungs while keeping adequate flow to other areas. The procedure can postpone the complete cardiac repair until the baby is older and larger, or it can be used in place of the open-heart surgery of pulmonary artery banding, thereby reducing the total number of surgeries a child requires.
"The risks related to open-heart surgery in neonates and infants, as well as risks during their recovery, substantially decrease the further the babies get from birth and the bigger they are," says Elizabeth H. Stephens, M.D., Ph.D., a pediatric and congenital heart surgeon at Mayo Clinic Children's Center. "This technology can be used, for example, for some babies born prematurely or at low birth weight, allowing them time to grow and mature prior to cardiac repair and resulting in decreased risk and recovery time."
One patient's experience
One infant treated at Mayo Clinic Children's Center had severe aortic valve stenosis and left ventricular heart failure. The patient was in severe heart failure, requiring inotropic support and respiratory support.
The team at Mayo Clinic placed a stent in the patent ductus arteriosus to maintain the connection between the pulmonary artery and the aorta. With a stent in place, as blood is ejected from the heart and enters the aorta, the blood can go either to the lungs or to the rest of the body (brain, kidneys, gut and extremities). Because the resistance in the lungs is lower than that in the rest of the body, the blood preferentially flows to the lungs and the body does not receive enough blood flow. To regulate this flow and balance the circulations, the Mayo team placed pulmonary flow regulators in the pulmonary arteries, completing the endovascular banding procedure.
The patient no longer required respiratory support and was in a stable circulation that allowed him to be held and fed. He was also able to grow while awaiting cardiac transplantation. The patient's first surgery was placement of a new heart. "The family placed their trust in Mayo Clinic knowing this was the best option for their son," says Dr. Anderson. "He is now home with his family, thriving with a new heart."
Innovation and collaboration at Mayo Clinic Children's Center
At Mayo Clinic Children's Center, work is always underway to develop and offer the newest procedures and technology to patients.
"Our aim is to bring disruptive technology to the field and to establish new standards," says Dr. Anderson. "Endovascular band placement is just one example. Rather than formulating a way to improve the surgery performed for decades, we sought to replace the surgery altogether. This requires a collaborative team willing to work together, learning from every procedure to perfect a new technique tailored to each patient," he says.
For more information
Mayo Clinic Children's Center.
Refer a patient to Mayo Clinic.