A congenital heart defect that used to be a death sentence is now treatable thanks to an approach based on “Fontan circulation.” But as people who received this procedure as newborns grow older, researchers are seeing more instances where additional procedures are necessary to sustain the health of the heart.
Image credit: Spc. Breanne Pye
Single-ventricle disease is used to describe a variety of congenital heart defects that have one thing in common: one of the two ventricles is not functioning to its full potential. More than half of the babies that survive the three stages of procedures required to resolve single-ventricle diseases will require another heart procedure within 20 years, a new study from the Children’s Hospital of Philadelphia (CHOP) reports.
Depending on which ventricle is dysfunctional, single-ventricle disease is treated with a series of procedures designed to ultimately reach Fontan circulation: doctors empower the fully-functioning side of the heart to pick up the slack from the other side. The fully-functioning side completes the more difficult job of pumping oxygenated blood from the lungs to the rest of the body, and the blood returning from the body travels to the lungs “by direct blood vessel connections” rather than by the help of a ventricle as a pump.
The procedures begin within the first week of a baby’s life. The Fontan operation is done when the baby is between 18 months and two years old. It is the third and final stage of the repair and is done to make sure deoxygenated blood coming from the body tissues stops by the lungs before going to the heart.
"Unfortunately, for many patients, the Fontan is not the final intervention," explained study leader Andrew Glatz, MD.
While the Fontan operation gives babies with single-ventricle heart defects the best chance of living a normal life, it cannot provide normal blood circulation - it cannot make the defect obsolete. Additionally, there is a long-lasting risk of complications that are not yet fully understood by scientists.
The new study from CHOP was a retrospective review of 773 patients who had the Fontan operation at CHOP between 1992 and 2009. Researchers looked at re-intervention rates; how many babies who underwent the Fontan procedure grew up to require an additional procedure?
Results showed that 65 percent of the patients in the review had to have a re-intervention procedure within 20 years of their Fontan operation. Catheter-based procedures were the most common, mostly to “close unwanted openings or to widen narrowed blood vessels.” For those who underwent an operation, usually it was to “place or revise” a pacemaker.
“Many patients require further interventions after the Fontan to continue to try to optimize the circulation as best as possible,” Glatz explained. “It's important for families and doctors to understand this, so expectations are clear.”
The present study was published in the journal Circulation: Cardiovascular Interventions.