Who needs a Fontan?
The Fontan Procedure is proposed to children who are born with abnormal hearts that cannot be repaired with two pumping chambers. In a normal heart each ventricle does a separate job. The right ventricle pumps blood to the lungs while the left ventricle pumps blood to the body.
Some children are born with one ventricle missing and have what is called a single ventricle. Others are born with two ventricles but one is too small to be really useful. In other cases, holes are present between two good ventricles but the connection between the ventricles and the collecting chambers and/or the vessels going to and out of the heart is so abnormal that it is impossible to close these holes and use separately the two ventricles.
After the Fontan procedure, all these children have a heart functioning with a single pumping chamber, they have a "functional single ventricle".