Fontan

Tyler is off to UCSF for his single ventricle completion, the Fontan, next week. He will have a cath on Monday to make sure his pressures are good. After Fontan, blood must flow through the lungs without being pumped by the heart. Therefore children with high pulmonary vascular resistance may not tolerate a Fontan. If pressures look good he will have his fontan completion on Wednesday.

Children, like Tyler, with hypoplastic left heart syndrome have a single effective ventricle supplying blood to the lungs and the body. They are delicately balanced between inadequate blood supply to the lungs (causing cyanosis) and oversupply to the lungs (causing heart failure). The single ventricle is doing nearly twice the expected amount of work (because it has to pump blood for both lungs and body). When they are large enough, and the pressure in the pulmonary arteries are low enough, these children are referred for Fontan.

The Fontan is done in two parts. The first part was done when Tyler was 7 months. The first stage, also called a Bidirectional Glenn procedure and involves redirecting oxygen-poor blood from the top of the body to the lungs. That is, the pulmonary arteries are disconnected from their existing blood supply (e.g. a shunt created during a Norwood procedure, a patent ductus arteriosus, etc) is taken out and blood redirected. The superior vena cava (SVC), which carries blood returning from the upper body, is disconnected from the heart and instead redirected into the pulmonary arteries. The inferior vena cava (IVC), which carries blood returning from the lower body, continues to connect to the heart. The second stage, also called Fontan completion, involves redirecting the blood from the IVC (inferior vena cava) to the lungs as well. At this point, the oxygen-poor blood from upper and lower body flows through the lungs without being pumped (driven only by the pressure that builds up in the veins). This corrects the hypoxia, and leaves the single ventricle responsible only for supplying blood to the body.

The Fontan procedure is palliative, not curative. But in many cases it can result in normal or near-normal growth, development, exercise tolerance, and good quality of life. Patients will eventually require heart transplantation.

We feel so blessed that Tyler has made it thus far doing as well as he has done. The first 8 months were the hardest, at times, not knowing if he would ever make it to this stage. We know that our Heavenly Father has blessed us with this precious time for Tyler to be in our family and teach us and others so much about life, faith and hope.

Several people have asked what they can do. Prayers would be the best. We will be updating our blog during this time so you can see how Tyler is doing. Tyler turns 4 on September 4th and we are hoping he is doing well enough to celebrate in the hospital or even better at home. We will see how it all goes.