Tricuspid atresia is a type of congenital heart disease in which the valve between the right atrium and right ventricle fails to develop. Instead, there’s solid tissue between the chambers.
When a child is born with tricuspid atresia, blood can’t flow through the heart and into the lungs to pick up oxygen as it normally would. The result is the lungs can’t supply the rest of your child’s body with the oxygen it needs. Babies with tricuspid atresia are easily tired and are often short of breath and have blue-tinged skin.
Tricuspid atresia is treated with surgery. Most babies with tricuspid atresia who have surgery will live well into adulthood, though follow-up surgeries are often needed.
Tricuspid atresia symptoms become evident soon after birth, and can include:
- Blue tinge to the skin and lips (cyanosis)
- Difficulty breathing (dyspnea)
- Tiring easily, especially during feedings
- Slow growth
Some babies with tricuspid atresia may also develop symptoms of heart failure, including:
- Fatigue and weakness
- Shortness of breath
- Swelling (edema) in the legs, ankles and feet
- Swelling of the abdomen (ascites)
- Sudden weight gain from fluid retention
- Irregular or rapid heartbeat
Treatment of Tricuspid atresia
The diagnosis of tricuspid atresia with too little blood flow to the lungs or to the body requires immediate medical treatment. In a newborn (less than 1 to 2 weeks old), a medication called PGE can be given intravenously to reopen the connection (ductus arteriosus) between the pulmonary artery and aorta and improve blood flow to the lungs or body.
Children with tricuspid atresia and too little pulmonary blood flow will require surgery to establish a connection between the arteries to the body and the arteries to the lungs. This type of operation is call a modified Blalock-Taussig (BT) shunt, and involves the placement of a small Gore-Tex tube between the artery to the arm (subclavian artery) and the arteries to the lungs (pulmonary artery).
If the problem is too much pulmonary blood flow (tricuspid atresia with a large ventricular septal defect), blood flow to the lungs will usually need to be limited to protect the lungs from becoming damaged by too much blood flow. This can be accomplished by placing a band around the pulmonary artery so that blood flow to the lungs is limited in a controlled way.
Finally, if the problem is inadequate blood flow through the aorta (tricuspid atresia with ventricular septal defect and transposition of the great arteries), blood from the normal size left ventricle will need to be routed to the aorta, and the aorta will usually need to be reconstructed. Pulmonary blood flow can then be established by placement of a modified BT shunt. This is essentially the Norwood procedure used for hypoplastic left heart syndrome.
Whatever operation is necessary in the newborn period, children can expect to undergo further heart surgery by the age of 3 to 6 months. This is true whether the child has too much or too little pulmonary or systemic blood flow in the newborn period and, therefore, did not require any surgery at that time.
The operation at 3 to 6 months is called a bidirectional Glenn. The superior vena cava is detached from the heart and connected directly to the pulmonary artery, and the BT shunt is removed. This allows blood from the upper body to flow directly to the lungs to pick up oxygen without having to be pumped by the heart. It also prevents blood that already has oxygen from returning to the lungs, and, thereby, keeps the heart from doing unnecessary work. After this operation, however, there is still blood returning from the body through the inferior vena cava going directly back to the body without first passing through the lungs. Because of this, some level of cyanosis will persist.
Between the ages of 2 and 5 years, children with tricuspid atresia will be ready for the third operation required to optimize their circulation. This operation is called the Fontan procedure, and involves connection of the inferior vena cava directly to the pulmonary artery, which forces all blood returning from the body to pass through the lungs and pick up oxygen before being pumped to the body. This allows a more normal color in the skin and lips as well due to a more normal oxygen saturation in the blood.
The results of this staged approach to the child with tricuspid atresia are generally good, with an expected survival through all three stages of 75 percent to 95 percent depending on the exact malformations and surgery for any given individual.
The long-term quality of life following the Fontan operation is generally good with the oldest patients currently in their mid-20s. However, several complications may occur. These include heart rhythm problems requiring medication or placement of a pacemaker.
Patients may also experience lung problems resulting in a decrease in oxygen in the blood or digestive problems caused by loss of protein in the stool resulting in swelling and water retention. For a minority of patients, heart and possibly lung transplantation may be necessary later in life.
Adult patients born with Tricuspid Atresia, have only one pumping chamber in their heart. As they age, many problems can occur, and Fontan patients need careful and thoughtful surveillance throughout their lives by experts in complex congenital heart disease. Many Fontan patients will have abnormal heart rhythms that require treatment. Some will have low oxygen levels in their blood that may limit their physical abilities, and that may require the blockage of abnormal vessels that were allowing blue blood to mix with red blood. Some Fontan patients may have weakening of their pumping chamber or leakage of one or more valves. Perhaps 10 percent of these patients may develop an unusual condition called “protein losing enteropathy.” This requires very careful management. Fontan patients may also develop problems with liver or kidney function, so this needs to be monitored as well.
Most women with a congenital heart disease history may be able to successfully carry one or more pregnancies. Women with complex forms of congenital heart disease should definitely receive counselling and assessment before becoming pregnant, and should have their pregnancy managed by a special maternal fetal medicine team skilled at managing pregnancy in women with other health conditions.