Operation was extremely dangerous but vital.
Dr Milind Chaudhari [corr] said the procedure involved removing a long "tunnel" running through the centre of her left heart pumping chamber.
Naomi was born with a hole between the right and left atriums of the heart, and was first operated on when she was 13 months old.
A complication arose and the left chamber of her heart was narrowed.
She then had a further operation aged five to try and cure this, but it did not solve all of the problems. Finally, surgeons decided to get rid of the tunnel, which was blocking Naomi's breathing.
They did this by removing crucial valves which supply the heart so the obstruction could be seen in more detail. They then managed to cut the tunnel out before reattaching the valves.
Dr Chaudhari said: "One risk is that you can damage the valves, which could block the heart, and even affect the coronary artery which is the main supplier of blood to the heart.
"Although it is too early to say it has worked perfectly, she has responded really well ( the narrowing has completely gone."