Also known as the “blue baby operation,” the Blalock-Taussig procedure is a surgery in which a detour (shunt) is created from the aorta to the pulmonary artery. The surgery is performed on infants and young children who are born with a congenital heart defect that reduces the amount of oxygen-rich blood circulating in the body. These infants often show signs such as a bluish tint (cyanosis) to the skin, lips, fingernails and other parts of the body.

The Blalock-Taussig procedure is performed as a temporary solution. In other words, it will improve the immediate signs and symptoms of the underlying  heart defect, but it will not correct it. Other surgeries are usually necessary in the future to repair the defect itself.

The surgery involves making an incision in the chest, but it is not an open-heart surgery and does not use the heart-lung machine. Parents can expect their infant to remain in the hospital for about three to six days after the surgery. Parents are also encouraged to discuss with a pediatric cardiologist and heart surgeon all benefits and risks associated with this procedure. In most cases, the benefits greatly outweigh the risks.

Also known as the “blue baby operation,” the Blalock-Taussig procedure is a surgery in which a detour (shunt) is created from a branch of the aorta to the pulmonary artery. The surgery is performed on an infant or child who is born with a congenital heart defect that results in diminished blood flow to the lungs, which in turn causes a lack of oxygen-rich blood circulating through the body. A child born with this kind of defect is sometime referred to as a blue baby because of the bluish tint to the skin, lips and other body parts.

The Blalock-Taussig procedure allows blood to flow from the aorta to the pulmonary artery and to the lungs, where it can be enriched with fresh oxygen. As a result, the level of oxygen in the child’s blood flowing to the body is improved and the child may show less of a blue tint (cyanosis) in various areas of the body, or may even show a fully natural skin tone. The procedure may also improve other symptoms, including fatigue and weakness, which can result from the defect. In addition, the child may demonstrate some improvement in growth and weight gain.

There are a number of heart defects that may require a Blalock-Taussig procedure. For example, the following heart defects interfere with the natural flow of blood from the lower-right chamber of the heart (the right ventricle) through the pulmonary artery and to the lungs, resulting in blood flow that seriously lacks oxygen:

• Tetralogy of Fallot. A condition that involves the “tetralogy” or combination of the following four elements: ventricular septal defect, enlargement (hypertrophy) of the right ventricle, narrowing (stenosis) of the pulmonic valve and a displaced/deviated aorta. These four heart defects lead to reduced blood flow to the lungs, a serious lack of oxygen-rich blood and cyanosis.
  
  
• Pulmonary atresia. A condition in which an infant is born with a completely closed pulmonic valve (the valve between the right ventricle and the pulmonary artery) or is missing a portion of the main pulmonary artery. As a result, blood cannot travel from the right ventricle through the pulmonary artery and to the lungs, resulting in a lack of oxygen-rich blood and cyanosis.
  
  
• Pulmonary stenosis. A condition in which the pulmonic valve is abnormally narrow, interfering with the flow of blood from the right ventricle through the pulmonary artery and to the lungs, resulting in oxygen-deprived blood and cyanosis.
  
  
• Tricuspid atresia. A condition in which an infant is born with a completely closed tricuspid valve (the valve between the right atrium and the right ventricle) and, usually, an undersized or absent right ventricle. As a result, blood cannot travel from the right atrium to the right ventricle, which would have pumped the blood through the pulmonary artery and to the lungs.
  
  
• Tricuspid stenosis. A condition in which the tricuspid valve is narrowed, interfering with the flow of blood from the right atrium to the right ventricle, which would have pumped the blood through the pulmonary artery and to the lungs.
  
  
• Hypoplastic left heart syndrome (HLHS). A condition in which the left side of the heart, including the left ventricle, aortic valve and aorta, is severely underdeveloped. As a result, the left ventricle is unable to pump enough oxygen-rich blood to the body, leading to cyanosis.

The Blalock-Taussig procedure is palliative, meaning that it helps relieve immediate symptoms, rather than reparative, meaning that the problem is repaired. Other surgeries to correct the heart defect itself will usually be performed when the child is stronger.

The Blalock-Taussig procedure creates a shunt between the pulmonary artery and a specific branch of the aorta called the left subclavian artery (which supplies oxygen-rich blood to the arm). Other shunt operations involve other branches of the aorta, or the aorta itself. These shunt operations include:

• Potts shunt, in which a connection is formed between the lower aorta and the left branch of the pulmonary artery.
  
  
• Waterston-Cooley shunt, in which a connection is formed between the back of the aorta and the right branch of the pulmonary artery.
  
  
• Davidson shunt (also called a central shunt or modified Blalock Taussig shunt) in which an artificial tube helps to form a shunt between the aorta and the pulmonary artery.

The Blalock-Taussig procedure is a “closed–heart” surgery, meaning that the procedure involves structures outside the heart. As a result, the heart is not stopped during the procedure and the heart-lung machine is not used.

Instead, after the young patient has been “prepped” for surgery and has been given general anesthesia, the surgeon will make a cut in the chest (a thoracotomy) to expose the pulmonary artery and the subclavian branch of the aorta, which runs out to the arm. The surgeon will then use one of two strategies to perform the Blalock-Taussig procedure:

• The surgeon attaches the subclavian artery to an artificial tube through which the blood will be shunted. The other end of the tube is then attached to the pulmonary artery. As a result, the detour is created without dividing the subclavian artery. This is sometimes referred to as a modified Blalock Taussig shunt.
  
  
• The surgeon divides the subclavian artery then turns it down and sews it to an opening in the side of the pulmonary artery.

After the surgeon has closed the initial incision, the surgery is complete and the infant is taken to a cardiac intensive care unit for recovery.

tal for about three to six days following the procedure if no complications arise. Depending upon the nature and severity of the heart defect(s) that caused the original lack of oxygen-rich blood and cyanosis, further surgery and/or additional treatment may be necessary once the child has become older.

Because the subclavian artery supplies oxygen-rich blood to the arm, there are some restrictions on whichever subclavian artery was used for the surgery (right or left). The affected arm should not be used for taking a blood pressure reading or taking a blood sample up to three months after surgery. Regardless of the specific future course of treatment, close medical supervision will be necessary for life.

Often a baby will be treated with a low dose of aspirin in order to avoid clots forming in the shunt.

Potential risks with Blalock Taussig

Complications of the procedure, while rare, can include:

• A blockage of the shunt and a return of the oxygen deficiency, resulting in cyanosis.
  
  
• Infection of the artificial tube.
  
  
• Too much blood flow to the lungs, which could damage pulmonary vessels and require future surgery.
  
  
• Uneven or distorted growth between the child’s heart and the artificial tube used for the shunt.
  
  
• Very rarely, complications with an arm or loss of arm.

Dr. Alfred Blalock, a surgeon, and Dr. Helen Taussig, a pediatric cardiologist, first developed the Blalock-Taussig procedure in 1944 at Johns Hopkins University in Baltimore, Maryland. Dr. Blalock had already established an excellent reputation through his discovery of why people go into shock, which saved countless lives during World War II.

Dr. Taussig was the head of the pediatric cardiology clinic at Johns Hopkins University, though  she was denied her first choice of internal medicine because of her gender. Dr. Taussig discovered the reason why many infants were being born as blue baby and Dr. Blalock had already developed a procedure that could be modified to treat the identified problem. Blalock and Taussig, along with laboratory technician, Vivien Thomas, developed their technique on laboratory animals and then on children, with great success. Their pioneering work was the foundation for the many complex techniques that have since been developed to treat certain types of heart defects.

Preparing questions in advance can help parents to have more meaningful discussions with their physicians regarding their child’s condition. Parents may wish to ask their doctor the following questions related to the Blalock-Taussig procedure:

1. What type of heart defect does my child have that makes this procedure necessary?
   
   
2. How will the procedure correct the problem?
   
   
3. Is my child a good candidate for this type of procedure?
   
   
4. Are there any alternative treatments available to my child?
   
   
5. Will someone who has experience with this specific procedure perform the operation?
   
   
6. What are the risks associated with this procedure?
   
   
7. How soon does the surgery need to be performed?
   
   
8. What will happen if my child does not have this procedure?
   
   
9. Are there any necessary preparations prior to the surgery?
   
   
10. What is the period of recovery for my child?
    
    
11. What are my child’s restrictions following the procedure?
    
    
12. What types of surgeries are necessary to permanently correct the defect?
    
    
13. How much time will this procedure give my child before further surgery is necessary?
    
    
14. Will my child need to take any medications after the surgery and for how long?