Fontan...

The procedure that Max will be having on Monday is called the Fontan. It is actually a 2 step procedure and he had the first part performed when he was 3 months old, now it is time for the final step. In a previous post I explained Max's anatomy, you might have to refer back to that to help understand the specifics of this surgery.

Since Max is missing his right ventricle, the doctors want to essentially reroute Max's blood to by-pass the right side of his heart. The right side of the heart has the function of pumping blood to the lungs, without his right ventricle the doctors need to get the blood to his lungs another way. The Fontan is how they do that.

The Pulmonary Artery (purple) carries blood to the lungs. The Superior Vena Cava (SVC, orange) is the large vein that carries blood from the upper part of the body to the heart. The Inferior Vena Cava (IVC, orange) is the large vein that carries blood from the lower part of the body to the heart. In a normal heart, the SVC and IVC carry blood to the heart, the right side of the heart then pumps the blood to the Pulmonary artery and then flows to the lungs.

 

Normal heart- showing the section where the SVC/IVC cross the Pulmonary Artery.

When Max was 3 months old, he had the first part of the Fontan procedure done, also known as a Bi-directional Glenn. During this surgery the doctors connected the SVC directly to the Pulmonary Artery. By doing that, the blood from the upper part of the body started to flow directly to the lungs, rather than pumping through the right side of Max's heart. The IVC still flowed into the heart.

SVC connected directly to the Pulomonary Artery. The IVC still flowed to the heart. 

 Now, for the final step of the Fontan, the IVC will also be connected to the Pulmonary Artery. After this surgery, all of Max blood will flow directly to his lungs, through the Pulmonary Artery and by-pass the right side of his heart. 

Both SVC and IVC will connect to the Pulmonary Artery. No blood will flow into Max's heart that is not coming from his lungs. 

How the Fontan benefits Max is remarkable. After this surgery his heart will have less work to do. He is missing 30% of his heart so the chances of his heart wearing out are much, much higher than another child or adult with a normal functioning heart. When Max was born, the single left Ventricle was doing double the work- pumping for both the right and left side of his heart. The Fontan takes away the work of the right side of the heart by having all the blood flow directly to the lungs. After this, his left Ventricle will only have to do the work for the left side of his heart- it won't have to work as hard. If the left Ventricle does not have to work as hard that means that it will continue to pump strongly for a much longer time! 

The actual procedure of connecting the IVC to the Pulmonary Artery is fairly simple. It is risky because the veins in Max's body are so tiny and everything needs to be very precise. The higher risks of the surgery occur because he will be on the Cardiopulmonary by-pass machine. Basically his body temperatures will be cooled to slow his blood flow, they will direct his blood through a machine and at that point they can stop his heart for a period of time while they operate. The by-pass machine freaks me out. That is the scariest part for me. Max's doctors have also explained that since this will be his 3rd open heart surgery, there will be a lot of scar tissue and it will take a while for them to cleanly open him up so he will be under anesthesia for quite a while. 

So that is what is happening to my baby on Monday morning. It is going to be so hard to let the nurses take him from my arms and then to have to sit and wait. It requires so much trust to let the doctors do this to my son. I have to have faith that everything will go well during surgery. Open heart surgery is so scary. 

So very scary!