New Technique Yields Better Survival in Infant Heart Surgery

A new study reports on the results of a recently introduced surgical procedure that offers infants with severely underdeveloped hearts a better chance at surviving during their first year of life.

Researchers at the Children's Hospital of Philadelphia (CHOP, PA, USA) and 14 other members of the Pediatric Heart Network across the United States studied the outcomes in 549 newborns who received a complex series of surgeries for hypoplastic left heart syndrome (HLHS). Part of the Single Ventricle Reconstruction (SVR) trial, the study compared two techniques used in the initial, riskiest stage of surgery, called the Norwood procedure, in which surgeons implant a shunt to reroute blood from the malformed heart to the pulmonary artery. The traditional surgical approach is to use a modified Blalock-Taussig (MBT) shunt, which carries blood from an artery branching off the aorta to the pulmonary artery. The newer technique, sometimes known as the Sano procedure or the right ventricle-pulmonary artery (RVPA) shunt, links the right ventricle to the pulmonary artery. If either technique fails, the only alternative is a heart transplant.

For the study, the researchers randomized infants who required the Norwood procedure to two groups, 275 for the MBT shunt and 274 for the RVPA shunt. The results showed that 12 months after the surgery, 74% of infants with the RVPA shunt survived and did not require a heart transplant, compared to 64% of infants with the MBT shunt. The RVPA group did, however, undergo a higher rate of complications requiring unintended interventions, such as needing stents or balloons to keep the shunt open. After the first year, rates for transplantation-free survival were the same for both groups. The study was published in the May 27, 2010, issue of the New England Journal of Medicine (NEJM).

"This landmark study is the largest clinical trial ever performed in congenital heart surgery, and the first randomized trial comparing two surgical procedures for congenital heart defects,” said senior author pediatric cardiothoracic surgeon J. William Gaynor, M.D., of CHOP. "It will be important to monitor these children as they grow and to not only make sure they are physically doing well, but also hitting developmental milestones.”

HLHS, which affects 1 in 5,000 live births, results when the left ventricle, one of the heart's two pumping chambers, is small and unable to function. Without treatment, HLHS is fatal in the first few days of life. Starting in the 1980's, surgeons developed surgical procedures for HLHS that have allowed increasingly more children born with a single functioning ventricle to survive. The intervention involves three planned surgeries, beginning in the newborn period and extending to 18 to 36 months of age.

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