Dr. Sushant Srivastava
Director & Sr. Consultant
Cardiothoracic & Vascular
Surgery
BLK Heart Centre
BLK Super Speciality
Hospital, New Delhi

The incidence of heart defects at birth is approximately 20 to 30 in one thousand live births. About four cases out of these happen to be serious defects, requiring palliative or corrective surgery in the first few weeks to prevent death. Transposition of the great arteries or TGA is one such condition.

This congenital heart defect is due to abnormal development of the foetal heart during the first eight weeks of pregnancy. In TGA, the large vessels that carry blood from the heart to the lungs, and to the body are swapped i.e. they are connected improperly. In other words, the aorta is connected to the right ventricle, and the pulmonary artery is connected to the left ventricle — the opposite of a normal heart’s anatomy. In a normal heart, oxygen-poor (blue) blood returns to the right atrium from the body, travels to the right ventricle, then is pumped through the pulmonary artery into the lungs where it receives oxygen. Oxygen-rich (red) blood returns to the left atrium from the lungs, passes into the left ventricle, and then is pumped through the aorta out to the body.

The interventricular septum can be intact and the only mixing of oxygenated and deoxygenated blood, necessary to keep the baby alive, occurs through the Atrial Septal Defect and Patent Ductus Arteriosus. These sick babies need early diagnosis and complex surgery to switch the aorta and pulmonary arteries to their correct position within the first three weeks of life. If surgery is delayed, the left ventricle becomes progressively weaker and incapable of taking the load off the arterial system.





THE CASE

A baby, diagnosed with TGA in his native country Sudan, was brought to BLK Super Speciality Hospital since, surgery for this defect was not available in his country. By the time, the reports were sent to BLK and the patient travelled to India, he was four and a half months old. The diagnosis was confirmed on ECHO wherein it showed the left ventricle had weakened considerably and was no longer thought to be capable of pumping in the systemic circulation. A corrective Arterial Switch operation was out of question.

THE PROCEDURE

The second best option for the infant was an Atrial Switch or Senning’s Operation. In this ingenious operation, three incisions are made, two in the walls of the right and left atria, and one in the atrial septum. They are re-sutured in a way that superior vena cava (SVC) and inferior vena cava (IVC) blood is diverted into the left ventricle, the pulmonary artery and oxygenated pulmonary venous blood is diverted into the right ventricle and aorta.

The operation was done through a mid sternotomy. The patient was put on the heart lung machine and cooled to 28 degrees. The aorta was clamped and the heart was stopped. Both atria were opened and the atrial septum was divided. A synthetic gore-tex patch was used to redirect pulmonary venous blood through the left atrium incision into the right atrium and right ventricle and through it into the aorta. The remaining right atrial wall was used to create a baffle to divert SVC – IVC blood into the left ventricle and pulmonary artery.

THE RESULT

The recovery of the child was uneventful. Cyanosis disappeared and the baby was discharged on the eighth post-operative day. During the follow-up, the child improved dramatically and gained weight within a fortnight, after which he was taken back home to Sudan for a healthy start all over again.