Reinforced Cardiac Shunt Helps Repair Serious Heart Defect

A new study shows that using a ring-reinforced shunt improves surgical outcomes in children born with hypoplastic left heart syndrome (HLHS).

Researchers at Boston Children’s Hospital (MA, USA) and Harvard Medical School (Boston, MA, USA) conducted a retrospective review of 87 patients with HLHS who underwent Norwood Stage-1 surgery. Of these, 48 patients received the standard, non-reinforced Gore-Tex right-ventricle-to-pulmonary-artery (RV-PA) conduit, and 39 received the same conduit, but reinforced with rings. The -reinforced graft was placed through a limited ventriculotomy. Primary and secondary outcomes were survival and need for cardiac re-intervention up to age 12 months.

The results showed that a ring-reinforced conduit was associated with reduced intervention, as well as higher pulse pressures and improved pulmonary artery (PA) growth. There was no difference in transplant-free survival by age 12 months, but those with the non-reinforced grafts had more interventions during their first year (69% versus 35%, respectively). Survival to discharge after the first stage Norwood surgery was 98% in the ring-reinforced group, compared with 83% in the non-reinforced group. In addition, survival at 12 months was higher in the ring-reinforced group (92% versus 75%). The study was published in the June 2015 issue of the Journal of Thoracic and Cardiovascular Surgery.

“The technique of using a ring-reinforced graft in conjunction with a limited right ventricular incision has theoretic advantages in preserving right ventricular function,” said lead author Audrey Marshall, MD, of the department of cardiology. “The ring-reinforced conduit maintains a uniform interior passageway for blood flow.”

“Although avoiding the use of a non-reinforced conduit may seem to be a minor adjustment in technique, the potential for important long-term patient benefit cannot be disregarded,” said Charles Fraser Jr., MD, of Texas Children's Hospital (Houston, USA) in an editorial commentary. “While the journey toward staged HLHS palliation was begun several decades ago and there have been many steps, it remains an arduous journey. Even a small step of progress encourages further focus.”

HLHS is a congenital defect in which the left side of the heart does not develop properly, impairing normal circulation. Children with this condition undergo a series of three reconstructive surgeries, called the Norwood Procedure, to help restore oxygenated blood flow. The first stage attempts to permit the normally functioning right ventricle to pump blood to both the lungs and the body. The second stage, the Bi-directional Glenn Shunt Procedure, follows when the infant is between four and six months old. The third step is the Fontan Procedure, which is carried out between 18 months to three years of age. Since only about 50% of children survive this three-part surgical series after five years, surgeons are always looking for ways to improve outcomes.

Related Links:
Boston Children’s Hospital
Harvard Medical School