Tricuspid Atresia

What is Tricuspid Atresia? 

Tricuspid Atresia is a cyanotic or “blue” heart disease characterized by complete failure of the development of the tricuspid valve. When you look at a normally developed heart, it is composed of four chambers. The two chambers that collect blood are called the right and left atria, and the two chambers that pump blood are called the right and left ventricles. When the blood returns from the body, it enters the right atrium. The blood then flows through a valve connecting the right atrium with the right ventricle. This valve is known as the tricuspid valve. The tricuspid valve serves as a doorway allowing blood to pass in one direction to the RV and then prevents it from flowing backwards. In Tricuspid Atresia, there is not a normal communication between the right atrium and the right ventricle. When the Tricuspid valve is “atretic” or underdeveloped, it prevents blood from entering the right ventricle and being pumped to the lungs. In-utero, if this flow of blood does not exist, it results in an underdeveloped right ventricle. A VSD or ventricular septal defect is generally present between the underdeveloped right ventricle and the left ventricle. These infants may have a larger than normal pulmonary valve annulus and main pulmonary artery or a smaller than normal pulmonary artery valve annulus and main pulmonary artery. There may also be excess tissue that may develop below the pulmonary valve annulus that can obstruct the blood flow to the lungs. Infants with tricuspid atresia usually fall into a category of congenital defects known as “single ventricles”. This simply means that for whatever reason one of the pumping chambers or ventricles is hypoplastic or absent.

What happens when Tricuspid Atresia occurs? 

Infants who are born with this congenital defect are usually well-developed and born on time. When an infant is diagnosed with tricuspid atresia in the neonatal period, the amount and source of blood flow to the lungs should be of immediate concern to the healthcare worker. Initial efforts are directed at complete relief of the systemic venous engorgement, and the securing of adequate and regulated pulmonary blood flow. With this diagnosis the “blue” or unoxygenated blood that returns to the right atrium from the body is unable to pass through the tricuspid valve into the right ventricle. The “blue” blood that would normally be passed to the right ventricle and pumped to the lungs to be oxygenated, now flows through the right atrium and into the left atrium through a “hole” in the atrial septum known as the Foramen Ovale. This “hole” is present in all unborn and nearly all newly born infants, usually closing within weeks after birth. When the “blue” blood is shunted through a “patent” or open Foramen Ovale, it mixes with the “red” or oxygenated blood returning to the left atrium from the lungs. This causes the infants to be bluish in color. Because an infant with tricuspid atresia may have too much or too little blood flow going to the lungs, the doctors must first assess this with an echocardiogram (a sonogram of the heart), and/or a cardiac catheterization. A balloon atrial septostomy is necessary for babies in which the Foramen Ovale is restrictive or too small to allow the passage of “blue” blood into the left atrium.

An infant with tricuspid atresia may also be diagnosed with too little pulmonary blood flow. This happens when there is a stricture or narrowing of the pulmonic valve or in the muscle underneath it that impedes the flow of blood to the lungs. On occasion, this stricture or “stenosis” can be so severe that the only blood reaching the lungs flows through the patent ductus arteriosus (PDA). If this is the case, Prostaglandins should be given to prevent closure of the PDA. The Prostaglandins should be continued until a Blalock-Taussig shunt (a plastic tube placed between the baby’s subclavian artery and the right or left pulmonary artery) is placed in order to insure continuous pulmonary blood flow.

Because the foramen ovale and the PDA usually close shortly after birth, healthcare workers must intervene quickly, making these temporary blood-shunting methods more secure until corrective surgery can be performed on the infant. An infant with tricuspid atresia may have too much blood flow to the lungs if there is no resistance to the flow of blood across the pulmonary valve. These infants may do well initially because of the high pressures present in a newborn’s lungs. Within a few days to a few weeks when the lung pressures start to fall to a normal level, these infants will usually present with congestive heart failure (CHF), due to the excessive blood flow to the lungs. A band may need to be placed on the pulmonary artery to restrict blood flow to the lungs.

What occurs if Tricuspid Atresia is left untreated? 

The answer to this question is very simple in most cases. When the diagnosis of tricuspid atresia is made, surgical intervention should be planned as soon as possible. The use of the drug Prostaglandin has given practitioners the ability to stabilize the infants and plan the first surgical intervention when the infant is as healthy as he/she can be. In general, the first surgical intervention usually takes place within the first few weeks of life.

When should Tricuspid Atresia be treated? 

The answer to this question is very simple in most cases.  When the diagnosis of tricuspid atresia is made surgical intervention should be planned as soon as possible.  The use of the drug Prostaglandin has given practitioners the ability to stabilize the infants and plan the first surgical intervention when the infant is as healthy as he/she can be.  In general the first surgical intervention usually takes place within the first few weeks of life. 

How is Tricuspid Atresia treated? 

When an infant is diagnosed with tricuspid atresia time is a major factor. All infants are born with a PDA. Although all infants are born with this vessel open, the PDA normally closes itself shortly after birth. The vessel in most cases is the only source of pulmonary blood flow to the pulmonary arteries for the infant. In most infants with tricuspid atresia, if the PDA begins to close, it severely compromises the blood flow to the child’s lungs. It can be kept open with the aid of an intravenous medication known as Prostaglandin. Because the PDA is usually the only source of pulmonary blood flow for these infants, prostaglandin is usually started as soon as the diagnosis of tricuspid atresia is made and is continued until the source of the infant’s blood flow to the lungs is stabilized or surgical intervention is performed. Prostaglandin is a good and effective drug, but it is not without its own risks. It must be administered intravenously and under close supervision of an experienced physician.

At birth, if adequate flow of the “blue” blood returning to the right side the heart does not exist through the Foramen Ovale, it may be necessary for the doctors to create a larger “hole” in the septum. In this instance an infant would be taken to the catheterization lab where a procedure known as a balloon atrial sepstostomy would be performed. During this procedure a “hole” in the wall between the two atria would be enlarged if the one present at birth was not of adequate size. Pulling a balloon tipped catheter across it can enlarge the “hole”. The hole in the septum would be ripped larger, improving the flow of blood, thereby unloading the right side of the heart. If this cannot be performed in the catheterization lab, the septum may have to be enlarged surgically in the operating room.
 

What is the Surgical Procedure for an infant with Tricuspid Atresia? 

As we said earlier the surgical intervention most commonly used for patients with tricuspid atresia does not have the ultimate goal of totally correcting the normal physiology of the heart.  We must remember that most infant who are diagnosed with tricuspid atresia have only three chambers of their heart that are functioning normally.  The goal of the surgical interventions must therefore be to preserve the existing anatomy of the heart, to secure a better oxygen delivery system for the body, and to eventually decrease the work of the single left ventricle which is now serving as the only pumping chamber for the heart.  This is achieved through a series of three surgical interventions spaced out over a period of the child’s first two years of life. 

Stage I:  Blalock-Taussig shunt 

The first surgical intervention is usually done soon after the infant is born.  This procedure is done to secure the infant’s blood flow to the lungs until the second surgical intervention can be performed.  As mentioned above, this initial surgery is known as a Blalock-Taussig shunt (BT shunt). This procedure may also be referred to as a systemic to pulmonary artery shunt.  In this procedure a connection is created between a systemic artery and one of the pulmonary arteries.  A direct connection between one of the infant’s subclavian arteries and the pulmonary artery can be made, or more commonly a synthetic tubular graft may be used to connect the two vessels.  By forming this connection the blood that is coming out of the aorta from the single pumping chamber of the heart will be shunted to the pulmonary artery.  The amount of blood that is shunted can be controlled by the size of the shunt that is used for the connection.  This procedure is a palliative procedure used to secure and control the amount of pulmonary blood flow that the lungs receive, in addition to promoting growth of the pulmonary vascular beds.  The B-T shunt is usually performed via a left or right thoracotomy (an incision under the arm).  This procedure is usually done without the aid of cardiopulmonary bypass, or the “heart lung machine”.  The use of a synthetic tube graft is known as a “modified B-T shunt.”  One end is attached to the subclavian artery and the other end is attached to the right or left pulmonary artery.  The optimal shunt size depends on the infant’s size, the anatomy and the resistance or pressures in the lungs.  If the PDA is small the doctor by opt to turn off the prostaglandin after surgery and allow the vessel to close on its own. 

Stage II Bidirectional Glenn or Hemi-Fontan operation: 

The second stage or surgical intervention is usually done when the child is around three months of age.  This procedure is known as the bi-directional Glenn.  Other names or variations of this surgery include: “Glenn procedure”, “Glenn shunt”, “classic Glenn”, and the “Hemi-Fontan”.  In this surgery the Superior vena cava or the blood vessel that returns blood from the head, neck and arms is connected directly to the pulmonary artery. This can be done on either the right or left side depending on the anatomy of the child.  The bi-directional Glenn is usually done through a mid-sternal incision and is usually done with the use of cardio-pulmonary bypass or the “heart lung machine”.   In this procedure approximately 1/3 of the blood returning to the right atrium through the venous system is directed through the connection from the Superior vena cava to the pulmonary artery.  Blood flows through the bi-directional Glenn with the help of gravity and is not pumped to the lungs by the heart.  Therefore the heart has to do less work. This procedure is known as a bi-direction Glenn because once the blood flows through the connection to one pulmonary artery it will continue to flow to both the right and the left side perfusing both lungs.  The pulmonary vascular resistance, or pressures inside the lungs is crucial for the blood to flow passively into the pulmonary arteries.  The Glenn procedure is done intentionally around three months of age for just this reason.  An infant’s pulmonary pressures are low at this point for the Glenn shunt and subsequent Fontan procedure to be a success.  Any previous systemic to pulmonary artery shunt is taken down at the time of the bi-directional Glenn surgery.  After the second surgery, or bidirectional Glenn the blue blood coming back from the Inferior vena cava, or from the lower part of the body, still continues to mix across the atrial septal defect.  This causes the bluish color of the patient’s skin to persist until the third stage or Fontan procedure is performed. 

Stage III Fontan Procedure: 

The third surgical intervention is usually completed when the child is around two years of age.  This surgery is known as the Fontan procedure.  The whole premise of the “Fontan” circulation for children with “single ventricle” anatomy is directing the entire systemic venous circulation to the pulmonary arteries without an intervening pumping chamber.  This ultimately separates the “blue” and “red” blood circulations.  The IVC blood flow is made to flow directly into the pulmonary circulation by creating a tunnel or baffle.  This connection has been termed a “lateral tunnel”.  The lateral tunnel can be an “intra-cardiac baffle” (a Gortex patch is used to create this inside the heart), or it can be an “extra-cardiac conduit” (a Gortex tube sewn outside the heart).  The intracardiac tunnel is created inside the right atrium directing all the IVC blood flow into the pulmonary arteries.  A fenestration or “hole communicating the lateral tunnel to the left atrium is sometimes made to act as a safety valve allowing the pressure in the Fontan circulation to remain low.  Cardio-pulmonary bypass is required for the “Fontan” procedure. 

What are some of the complications that may occur with the three stages of surgery for Tricuspid Atresia? 

The following complications may arise from the three stages of surgery used in the treatment of tricuspid atresia.  Some complications such as bleeding, possible need for a blood transfusion, infections and death are not unique to the surgery used to treat tricuspid atresia, but can occur in any operation.  The following complications are listed individually for each of the three stages. 

Blalock-Taussig shunt or BT shunt:

Phrenic nerve injury (This nerve moves one half of the diaphragm or breathing muscle and may require placation if the baby cannot come off the ventilator)

Recurrent nerve injury (this nerve moves one side of the vocal cords)

Glenn Procedure:

Pleural effusions

Fontan Procedure - see above procedure

 The following usually occur later: 

Contact Information:

John Mark Morales MD, FACS, FAAP
Chief of Cardiothoracic, Director of Perfusion Services
Certified by the American Board of Surgery, American Board of Thoracic Surgery

Mark Bielefeld, MD
Driscoll Children's Hospital Chief of Staff
Certified by the American Board of Surgery, American Board of Thoracic Surgery

Thoracic surgeons are available for questions and consultations: (361) 854-0201. For appointments, assistance, and physician references in Corpus Christi call: (361) 854-0201 or 800-DCH-LOVE
Fax : 361-855-7572
E-MAIL : jmarkmorales@aol.com

For further information on any surgical procedures you can contact Carol Kaplan, RN, Surgical Nurse Liaison at (361) 694-5150. Consultation and surgery for inpatients is provided in concert with neonatology and pediatric cardiology departments. Complete evaluation and management for infants, children, adolescents and adults with congenital or acquired cardiac, vascular or thoracic anomalies.

Cardiothoracic Associates
3533 S. Alameda, Suite 202
Corpus Christi, Texas 78411
Phone: (361) 694-5150
Fax: (361) 855-7572
Hours: 9am to 6pm
Fri 9am to 5pm

Learn More

Cardiothoracic Surgery Videos

Surgery Procedure Videos

Further Reading

For Patients and Parents

Contact a Social Worker

Day Surgery

Child Life

Need a Spanish Interpreter?

Urgent Care Center - After Hours

Pediatric Specialties

Rights and Responsibilities

Patient Billing

Visiting a Patient

Health and Safety Programs

Support Groups

Miracle Stories

Additional Resources

Pastoral Care

Create a CarePage

Visit Carousel Gift Shop to
Send a gift to a patient

Volunteer Opportunities

Ways to Give

Cardiothoracic Surgery, Mark Morales MD

Learn about ECMO for: