At Texas Children's Hospital, it's a condition that is addressed with surgery an average of 50 times a year.
The condition is referred to as a tetralogy case. About three children in several thousand are born with the defect. Those with the most extreme form are more rare, and that includes Kimmel's son.
"There are no one-way valve to get blood out to the lungs, so there is no way to get blood from the right side of the heart out to the lungs," said Dr. Jeff Heinle. He is one of eight congenital heart surgeons at TCH.
Without surgical intervention, the condition can be a death sentence.
Newborns were first treated surgically in the 1950s. The lessons learned on tiny patients eventually translated into new techniques on adult patients. Among the pioneers was renowned Houston heart surgeon Denton Cooley.
The infant surgeries are performed with strong magnification considering the size of their bodies.
"If you take a regular sized strawberry, that's the size of the body's heart. If you take a small bottle of Ozarka water, that's the amount of blood in a baby's body," said Dr. Heinle.
A tiny shunt allows blood to get to the lungs. As the child grows, more surgeries follow, until the permanent heart repairs can be done.
Barring any major setback, Dr. Heinle said patients have gone on to be athletes and even heart surgeons.
"Out in the community, they are very functional. They go on to have jobs, have families. All of that," Heinle added.
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