MONDAY, Jan. 9 (HealthDay News) -- Children who have heart surgery at high-volume hospitals may fare better than those who are treated in hospitals that perform fewer pediatric cardiac surgeries per year, but this is not due to volume alone.

New research suggests that the busier centers are more able to spot and handle complications should they occur after heart surgery.

Of more than 35,000 children who had heart surgery at 68 hospitals, nearly 4 percent of children died in the hospital, and almost 41 percent experienced at least one complication after their surgery, a new study found.

Centers that performed more than 350 surgeries a year were considered "high volume," while those that performed fewer than 150 heart surgeries in children each year were "low volume." The complication rate was similar across all centers. That said, the risk for dying after a major complication was higher at hospitals that performed fewer than 150 pediatric heart surgeries a year, when compared to those centers where more than 350 heart surgeries were performed a year, the study showed.

The new findings appear online Jan. 9 and in the February 2012 print issue of Pediatrics.

"Higher mortality observed at lower-volume centers appears to be relate to a higher rate of death in those who suffer a postoperative complication, rather than a higher rate of complications alone," said study author Dr. Sara Pasquali, director of pediatric cardiovascular outcomes at Duke University Medical Center in Durham, N.C. "This suggests that initiatives aimed at improving patients outcomes may need to focus not only on reducing complications themselves, but on better recognition and management of complications once they occur."

Parents of a child in need of heart surgery may feel both scared and overwhelmed by the entire prospect and process.

"Several studies have now found that higher volume hospitals tend to have better outcomes, particularly for more complex cases," Pasquali said. "Volume is not the only important factor and that there are smaller hospitals with outcomes comparable to those at larger centers. Overall, a hospital's past track record with similar types of cases may be the best information to consider rather than relying upon the volume of the center alone."

Dr. Rubin Cooper, chief of pediatric cardiology at Cohen Children's Medical Center in New Hyde Park, N.Y., said high-volume centers are not always an option based on where a patient lives and the urgency of the surgery.

"There aren't that many centers that do so much," Cohen said. "High-volume centers may have more tools and more surveillance, but low-volume centers all have board-certified people who are trained to know what they can and can't do, and they certainly would refer a case that they could not handle. Some children do need highly specialized centers if they have a rare condition." However, he added, "I would say as many as 80 percent of pediatric heart patients can be treated by nearly all of the programs."

More information

Visit the U.S. National Institutes of Health to learn more about pediatric heart surgery.