Pediatric heart surgery Heart surgery home Congenital heart defects Atrial septal defect Ventricular septal defect Tetralogy of Fallot    Transposition of the     great arteries Having congenital heart surgery Before surgery Day of surgery After surgery

Transposition of the great arteries (TGA) is a malformation in which the two great arteries carrying blood away from the heart are transposed or reversed. The pulmonary artery, which normally carries oxygen-poor blood from the right ventricle to the lungs, arises from the left ventricle. The aorta, which normally carries oxygen-rich blood from the left ventricle to the rest of the body, arises instead from the right ventricle.

This malformation is incompatible with life unless some communication exists between the two separate circulatory systems. Frequently, patients with TGA have atrial and/or ventricular septal defects or other types of shunting that allow some mixing of the circulations in order to minimally support life. Without some type of intervention, however, infants with TGA will die within their first year of life.

What are the signs of TGA?

Symptoms of TGA are profound and usually observed shortly after birth:

• Cyanosis (bluish discoloration of the skin caused by oxygen-poor blood)

• Heart failure

• Difficulty breathing

What are the surgical treatments for TGA?

An arterial-switch procedure is the surgery for TGA.

How is TGA surgery performed?

The arterial switch operation is a corrective procedure performed within the first few weeks of a child’s life. The overall goal of the operation is to restore the great arteries to their correct positions within the heart.

First, the chest is opened via an incision through the breastbone. The heart is inspected to confirm anatomy of the coronary arteries. This is very important because the delicate coronary arteries will need to be switched along with the great arteries.

After evaluating the coronary arteries, the patient is connected to the heart-lung bypass machine. The aorta is cut away from the right ventricle above the aortic root where the openings to the coronary arteries lie, and the pulmonary artery is transected from its root above the left ventricle. The coronary arteries carefully are cut away from their original location on the aortic root arising from the right ventricle and relocated to the native pulmonary artery root arising from the left ventricle. Next, the aorta is relocated to the native pulmonary artery root above the left ventricle and sutured in place. This now is the new aorta. An incision then is made in the right atrium, and any atrial or ventricular septal defects are repaired.

Once the atrial incision is sutured closed, the aortic root remaining above the right ventricle is reconstructed with patches of pericardial tissue at the locations where the coronary arteries were removed.

Finally, the pulmonary artery is relocated to the former aortic root and sutured in place – this will now become the new pulmonary artery. The remainder of the operation then is completed.

See having heart surgery for general information about preparation, surgery and post-operative recovery for congenital heart surgery procedures.