Transposition of Greater Arteries (TGA)

What is Transposition of Greater Arteries?
Why do the surgery?
What to ask your surgeon
The surgical procedure
Risks and benefits of the surgery
What to expect during the hospital stay
Going home
Long-term prognosis 

What is Transposition of Greater Arteries?

Illustration by Steven P. Goldberg, MD
Copyright © 2012 STS

Transposition of Greater Arteries (TGA) is the most common form of congenital heart disease that causes babies to be blue when born (cyanosis). In a normal heart, the pulmonary artery carries oxygen-poor blood from the right ventricle of the heart to the lungs, where it receives oxygen. The aorta carries the oxygen-rich blood from the left ventricle of the heart to the rest of the body. Transposition of the arteries occurs when the pulmonary artery and aorta are switched (transposed) so that the pulmonary artery is attached to the left ventricle and the aorta is attached to the right ventricle. This problem means that oxygen-poor blood is being pumped to the body, and because the blood does not have enough oxygen, the baby appears blue. 

Why do the surgery?

Infants with TGA need surgery within the first few weeks of life. Without surgery, the severe lack of oxygen in the blood will cause damage to organs and death.

Some children with TGA also have other heart conditions such as a ventricle septal defect (a hole between the right ventricle which pumps blood to the lungs, and the left ventricle which pumps blood to the body), an atrial septal defect (a hole between the right atrium which receives blood from the body, and the left atrium which receives blood from the lungs), or a patent ductus arteriosus (which is when a blood vessel named the ductus arteriosus fails to close shortly after birth [The ductus arteriosus is a passageway that allows most of an infant’s blood to bypass the lungs while it is still in the womb, which is needed because the lungs are filled with fluid. The ductus arteriosus normally closes within a few days after birth]). Although these other conditions need to be corrected, it is actually good that children with TGA have them. Each of these conditions results in a mixing of oxygen-rich blood from the lungs and oxygen-poor blood from the body that normally does not occur. Children with TGA have oxygen-poor blood being pumped to their body. If these other conditions are present, some oxygen-rich blood is mixed with oxygen-poor blood, so children with TGA will get some oxygen-rich blood to their organs that will help temporarily until surgery can be performed.

If these other conditions do not exist and there is no mixing of oxygen-rich and oxygen-poor blood, two emergency procedures will be used shortly after birth to temporarily help until surgery can be performed: (1) a medication called prostaglandin (PGE) will be given intravenously (in an IV) to cause the ductus arteriosus to reopen, and (2) a non-surgical procedure called balloon atrial septostomy will be used to make a hole in the wall between the left and right atriums, essentially creating an atrial septal defect. The balloon atrial septostomy is done by a pediatric cardiologist, usually in a cardiac catheterization laboratory.

What to ask your surgeon

The following are questions that you should ask your surgeon before any surgical procedure is performed:

  • What can happen if we do not do the surgery?
  • What about immunizations?
  • When should we do the surgery?
  • Will my child be in pain?
  • Where will the incision be made? What will it look like?
  • What is the experience of the surgical team?
  • How long does the surgery take?
  • Do you have specialized Intensive Care staff?
  • What is the risk of the surgery?
  • Can I stay in the hospital with my child?
  • How long will my child be in the hospital?
  • What should we bring to the hospital?
  • What will my child look like right after surgery?
  • Will my child be on any medications after surgery?
  • What can I expect during the hospital stay?
  • Will my child need another surgery later on in life?
  • What will my baby eat?

 

The surgical procedure

Illustration by Steven P. Goldberg, MD
Copyright © 2012 STS

The surgery to correct TGA is called an arterial switch operation.  It is usually done in the first few weeks of the child’s life. The surgeon makes an incision down the front of the chest (called a median sternotomy) and divides the breastbone (sternum) in half to get access to the heart. The heart is placed on cardiopulmonary bypass, meaning that a machine takes over the heart’s job of pumping of the blood so the surgeon can enter the heart to repair it.

The repair consists of the following steps:

  1. The aorta and pulmonary artery are cut away from the heart
  2. The tiny coronary arteries are removed
  3. The aorta and pulmonary artery are re-implanted in the correct locations
  4. The tiny coronary arteries are re-implanted into the aorta
  5. Other conditions are corrected. If there is a hole in the wall between the ventricles (ventricle septal defect), it is closed, usually with a patch. If there is a hole in the wall between the atriums, either at birth or as a result of the balloon septostomy, it is closed, sometimes with a patch. If the ductus arteriosus is open, it is closed.


      When the breastbone is put back together, stainless steel wires are usually wrapped around the bone to make it very sturdy. The surgery can take from four to eight hours from start to finish.

      Risks and benefits of the surgery

      The benefit of the surgery is for the child to have a normally functioning heart and normal levels of oxygen in the blood.

      Risks of any heart surgery include: bleeding, infection, stroke, organ damage, requirement for a temporary or permanent pacemaker, or possibly death. For 99% of all pediatric heart disease surgical procedures, the risk of these occurring is 5% or less. After the arterial switch operation, most children do not require any additional surgery after the first one. The patch closing the holes between the ventricles or atriums can come loose, requiring another operation to repair it, but this is extremely rare. Narrowing may develop in the blood vessels that have been switched and this narrowing may require additional surgery later in life to widen those areas.

      What to expect during the hospital stay

      The length of the hospital stay can vary from one to four weeks. Before being allowed to go home: (1) the baby needs to be able to breathe on his or her own without a ventilator, (2) the baby’s heart needs to recover from surgery, (3) the excessive fluid that the baby’s body retains during the initial day of surgery needs to be shed, and (4) the baby needs to learn to eat. It is this last step that usually keeps the baby in the hospital the longest.

      Just after surgery, the baby will be sedated while recovering from anesthesia and will likely have short periods of wakefulness in the next 24 hours. The baby will be using a ventilator to breathe. The baby may have nothing but glue over the outside over the surgical incision in the chest and will have many tubes and wires attached.

      During the recovery period, the baby’s chest will be x-rayed daily, and in the beginning, the baby will be fed intravenously and through a small tube. Over time, more of the wires and tubes will be removed and eventually the baby will eat on his or her own. Over time, the primary focus of care will involve getting the baby moving, making sure the baby is breathing well, and ensuring that caretakers are comfortable handling the child.

      Going home

      The hospital will supply specific discharge instructions, and all instructions from the hospital, cardiac surgeon, and cardiologist should be strictly followed. The baby should be seen by a cardiologist within two weeks after discharge from the hospital. The incision should be kept clean and dry until it is healed. It should also be protected from the sun for a full year. The child should not be picked up under the arms for four weeks following surgery. Any of the following symptoms should be reported immediately to the cardiologist: (1) fever greater than 101, (2) redness, puffiness, discharge from the incision, or (3) the baby not feeding well.

      Long-term prognosis

      It is important that the child be in the care of a cardiologist through his or her life so that physician can monitor the growth of the pulmonary artery and aorta and the function of the heart. Many children will never need another surgery. Once recovered from the surgery and cleared by the cardiologist, the child can usually be treated as any other healthy child, without restrictions. The cardiologist will alert caregivers to any exceptions to this.

      Written by Jeffrey P. Jacobs, MD and Heidi Hess, RN - Reviewed September 2012

|||