What is TGA (Transposition of the Great Arteries)?
Transposition of the great vessels (Transposition of the Great Arteries / TGA) is a congenital heart defect in which the aorta and pulmonary artery are reversed.
In a normal heart, the pulmonary artery will be connected to the right ventricle and the aorta to the left ventricle. The right ventricle is pumping as oxygen-depleted blood to the lungs, and the left ventricle is pumping, in turn, oxygen-rich blood to the rest of the body. In a heart with oxygen-rich blood TGA will be pumped to the lungs (where it will not take up additional oxygen), and oxygen-depleted blood to the rest of the body (through which brains, muscles and other organs no oxygen get invoked). This is thus only compatible with life as well as elsewhere, other defects exist in which blood circulations in the two mixes.
History
Transposition of the Great Arteries / TGA was first described in 1797 by Matthew Baillie.
Features of the patient
Patients with this condition will lack of oxygen blue colors. As the further development will be seriously hampered the patient without treatment will not be older than one year.
Treatment
1st treatment
Immediately after birth will sit a hole between the left and right atrium (foramen ovale). This oxygen-rich blood to mix with oxygen-poor blood. The first treatment is designed to keep the hole open and increase if possible through medication or catheterization (also known as the Rashkindprocedure). Furthermore, a child after his birth also has a connection cable between the two arteries, the ductus arteriosus, which slowly closes. With the aid of a prostaglandin (no NSAID) this vein can be kept open.
Corrective surgery
Surgery is the only way to sustainable recovery of the patient. In principle, two operations are possible. A correction in the inner upper side of the heart into the atria (Mustard or Senning correction) and an outside of the heart, on the upper side of the heart / underside of the large vessels (the more modern Arterial Switch).
Mustard or Senning correction
After this operation, the blood that enters in the right atrium diverted to the left ventricle, and blood that enters into the left atrium is diverted to the right ventricle. The disadvantage of this procedure is that now results in a reversed heart. The (usually) weaker right ventricle is now used for heavy work (namely pumping blood through the rest of the body) and increased left ventricle is used for lighter work (namely pumping blood to the lungs). Another disadvantage is that because there is an inverse heart also creates more pressure on the right ventricle is causing the valve to leak. An advantage of the procedure is that it can be applied at a later age. Nowadays, patients are preferably treated with an arterial switch.
Rastelli
After this procedure is the blood that enters in the right atrium diverted to the left chamber via a tube. The advantage of this procedure over the Mustard / Senning and Arterial Switch correction is that again an anatomically normal situation arises. What part is left then left again and hear what is right then right again, including the valves. However, there is now a tube through the chamber which means that it has less content. The advantage with respect to the Nikaidoh is that the location of the coronary arteries is not important.
Arterial Switch
In this procedure, the two arteries of the heart to be disconnected, reversed and fixed again put. The advantage of this procedure over the Mustard / Senning correction that again is a normal anatomical situation arises. What part is left then left again and hear what is right then right again. The disadvantage is that the operation should take place as early as possible in connection with the (strength) development of the heart muscle. In addition, this is a complicated procedure because the coronary arteries to be transferred. The infant's heart is not much bigger than a walnut so that the necessary knowledge and skill of the surgeon is expected. In the near future this procedure could probably be applied to adults who have received prior Mustard / Senning correction. It'll be the left ventricle to be stronger again, because he has become less muscular because he had to do less work. If the coronary arteries are complex, this procedure is not straightforward.
Nikaidoh
In this procedure, the two arteries of the heart to be disconnected, reversed and fixed again put. However, are now also changed to the corresponding valves. The advantage of this procedure over the Mustard / Senning and Arterial Switch correction is that again an anatomically normal situation arises. What part is left then left again and hear what is right then straight again, including the valves. If the coronary arteries are complex, this procedure is not straightforward.