Although we had failed in our numerous attempts to produce the cardiac abnormality in the experimental animal, we had, nevertheless, been trying to develop some surgical procedure that might be used to increase the life expectancy of patients with complete transposition of the great vessels-the aorta and the pulmonary artery. In this relatively common congenital malformation of the heart, these vessels have swapped their points of origin. The aorta, which normally carries oxygenated arterial blood to all parts of the body from the left ventricle, arises instead from the right ventricle, which receives unoxygenated venous blood from the body by way of the superior and inferior cavae. The pulmonary artery, which normally carries unoxygenated venous blood from the right ventricle to the lungs to be oxygenated, arises instead from the left ventricle, which receives the oxygenated blood from the lungs by way of the pulmonary veins and left auricle.
This arrangement of vessels essentially sets up two separate circulations: one systemic, in which the right side of the heart recirculates unoxygenated blood throughout the body, the other pulmonary, in which the left side of the heart recirculates oxygenated arterial blood through the lungs. The condition in itself is, of course, incompatible with survival, since no oxygenated blood can get out into the body. These patients, however, do have communications between the two systems, interatrial and/or interventricular septal defects or some combination of anomalies. The size and type of the communications between the two sides of the heart determine the amount of mixing of blood between the systems and thereby the time of survival. The more the mixing, the longer the patient will tolerate the condition and live.
Our thinking at the time suggested getting more oxygenated blood into the right side of the heart, from where it would be pumped directly through the aorta into the general circulation. The right pulmonary veins and right atrium lie in close proximity. Seemingly an easy and simple way to accomplish our aim would be to use a pulmonary vein, which was returning oxygenated blood to the left side of the heart, and reroute it directly into the right atrium.
In these experiments, the right pulmonary vein from the cardiac and apical lobes of the right lung was dissected free along the margins of its