Atresia is defined as the congenital absence of a normal opening. In the case of tricuspid atresia, the tricuspid valve is not present resulting in a lack of communication between the right atrium and the right ventricle. Consequently, the right ventricle is small and underdeveloped. An associated ASD allows blood to be diverted from the right to the left atrium. Survival depends on the presence of a VSD or on the ductus arteriosus remaining open after birth in order for blood to reach the lungs.
Corrective surgery is done in a series of three stages. The first stage, performed in the first days of life, is known as a Shunt Operation. During this procedure, a small tube (shunt) is placed between the aorta and the branch pulmonary artery. This helps increase blood flow to the lungs. The second and third stages are collectively known as the Fontan Procedure. The second procedure, performed at approximately six months of age, creates a Bi-directional Cavo Pulmonary Connection (BCPC).
This involves connecting the superior vena cava to the right pulmonary branch artery. The BCPC allows the deoxygenated blood of the upper half of the body to flow directly to the lungs. The shunt placed during the first stage operation is also ligated at this time. The third and final stage is performed at approximately 12 months of age. During this procedure, the deoxygenated blood of the lower half of the heart is directed to the lungs. This is done by channeling the blood of the inferior vena cava through the right atrium to the right branch pulmonary artery.
View an animated heart with Tricuspid Artresia