By Elizabeth Cohen, CNN Senior Medical Correspondent
Take a look at a newborn's tiny fist. Now imagine the fist is a heart -- they're about the same size -- and a surgeon must operate on it. Patch up holes. Widen vessels the diameter of a cocktail straw. Sew in thin plastic tubing.
By Elizabeth Cohen and John Bonifield, CNN Medical
She was only 7 weeks old, weighed a mere 10 pounds, and had just had delicate surgery to widen a narrowing in her aorta, the vessel that carries blood from the heart to the rest of the body. If that wasn't enough, after the surgery, Layla McCarthy stopped moving her legs. The doctors couldn't explain why.