Wednesday, September 5, 2012

Transposition of the Great Arteries

*All information included in this article comes from the personal experience of having a child with TGA. My education comes from my son's pediatrician, Dr. Sushant Navalkar, who has a neo-natal cardiology background, and from the cardiology team at Columbus Children's Hospital in Columbus Ohio, including my son's surgeon, Dr. Galantowitz. Transposition of the Great Arteries, also known as Transposition of the Great Vessels, is a serious congenital heart defect. That is, it is a problem with the heart which is present at birth. TGA, as it is commonly known, can be detected before birth by ultrasound, but if doctors are unaware, symptoms will be present immediately following the cutting of the umbilical cord. Infants with TGA require immediate medical attention, and must have open heart surgery in order to survive.
What is TGA? Sometime during the first nine-fourteen weeks of pregnancy, the heart of the fetus develops. In some cases, the heart can develop improperly. If the Aorta and the Pulmonary valves develop reversed, the fetus will be a TGA baby. In very simple terms, this causes blood with little or no oxygen to be carried throughout the body, and the blood with oxygen is simply returned to the lungs.
What happens to a TGA baby at birth? Due to the nature of this defect, the fetus is safe during pregnancy. The heart of the mother is doing the work for the baby, and oxygen is being provided by the mother's umbilical cord. Problems will present directly following birth and the cutting of the umbilical. Although the baby can be born looking completely normal and healthy and even crying, the effect of cutting the cord will be immediately apparent. Since the baby's heart is not formed properly and now has to work for itself, he will rapidly go into respiratory distress and his color will "go bad". He will have a very ashen or even blue cast to his skin. In most cases, intubation is required so that the infant can breathe. This means that a breathing tube is inserted into his lungs. Unfortunately, when a newborn is intubated, he will probably also have to be "paralyzed" with medication so that he will not dislodge the breathing tube and cause further damage.
The infant will then have to spend time in a NICU (neo-natal intensive care unit) or a CICU (cardio intensive care unit). If proper facilities are unavailable at the birth hospital, the infant will be transported by life flight or mobile intensive care unit to the nearest facility equipped to deal with his condition.
He will be connected with life saving medications such as antibiotics, as it is very important to avoid infection in a pre-op heart patient. It may also be necessary to preform a heart catheterization to help blood flow better for the infant while he is awaiting his open heart surgery. This is where a "balloon" is inserted into an artery in the thigh, transferred into the heart, and "bursts" a temporary hole between two chambers of the heart. Also, in a normal heart, there are holes in the heart which close naturally anywhere from immediately to within days of cutting the umbilical cord. For a TGA baby, it is important to keep these holes open also to help with blood flow. So he will have to be on a special medication to do this. Also, while in the ICU, he will have to be fed through a breathing tube, while he is intubated.
Some heart surgeons believe that the out come of the repair surgery will be better if the baby is able to breathe and eat on it's own before the surgery. Doctors will decide if the baby's stats and clinical health are good enough to remove the feeding and breathing tubes. If this is the case, parents may be able to hold and feed the baby at that time.
The Arterial Switch Surgery
Within the past twenty years, a new much more effective surgery is preformed to repair the hearts of TGA children. This surgery is the Arterial Switch Surgery. When exactly the surgery is preformed is at the discretion of the surgeon, however it is typically done as soon as the infant is strong enough; within the first few weeks of life. When the infant is taken into surgery, they begin by putting him on a heart lung bypass machine. Then they lower his body temperature. After that, they very simply, cut and then reverse the mal-formed arteries. These major arteries are also embedded in many tiny capillaries that also have to be cut and then repaired. The surgery lasts for six hours, and it may be about ten hours before the family can be reunited with the child. In many cases, the change in the infant is immediate and dramatic. Everything about them will improve so drastically, they may actually be released from the hospital in less than a week!
A lot of the information circulating about TGA refers to the surgery which used to be preformed called the Mustard or Senning procedure. Such information can be worrisome to parents because this particular procedure didn't get as great of results as the Arterial Switch surgery, and many more complications could result. It is important for TGA parents to know what they're reading, and understand that each case is different. Also, since the Arterial Switch Surgery is so new, cardiologists can only guess about long term prognosis, so don't distress if you hear something like, "TGA children can live relatively normal lives into their twenties." It doesn't mean things will start going wrong at that time, it simply means that is the extent of our factual knowledge at this time.
Life after surgery Long term prognosis is VERY good for TGA babies. The surgery is considered "curative", meaning that once they've had it, their problem is corrected. It won't ever go back to the way it was pre-op. There are some things that can occur in TGA people who've had the Arterial Switch surgery such as narrowing of the arteries, and higher risk of developing infections. However, most complications which can arise are fairly simply corrected and further open heart surgery should not be necessary. To prevent infections, TGA people should take antibiotics for a few days before they get dental treatment, or before they have any invasive procedure. However, even that is not necessary with every patient.
Yes, a TGA baby will need to receive life long follow up care with cardiologists. However, these visits can be a happy, "don't worry, everything's doing great!" and send them on their way. In some cases, later in adolescence, there may be some restrictions such as not playing contact sports. But, cardio exercise is good for TGA patients, and it really just boils down to making sure they don't do more than they can handle.
It is always important for a TGA parent to be on the look out for signs of congestive heart failure, even though this is usually not a concern. A TGA child should be brought to medical attention immediately if he sweats profusely while eating, becomes lethargic, or gets out of breath very easily.
This ordeal can be extremely trying for a parent. But, the best thing about it is that the TGA child receives his treatment when he is so young that he will never remember it. The bodies of infants are shockingly resilient. The recovery time for an adult that had surgery like this would be from six months to a year. A TGA baby that has the Arterial Switch surgery can be a smiling, happy, normal baby in a week. It is simply amazing, and one of God's finest miracles.