The Mustard procedure was developed in 1963 by Dr. William Mustard at the Hospital for Sick Children in Toronto, Canada. It was the first procedure to show that congenital heart defects could be repaired.
Dr. Mustard, with support from the Heart and Stroke Foundation of Canada, developed the first operation to correct a congenital heart defect that produced “blue babies”. The defect is called transposition of the great vessels. The condition was common and fatal. The defect causes blood from the lungs to flow back to the lungs and blood from the body to flow back to the body. This occurs because the aorta and the pulmonary artery, the two major arteries coming out of the heart, are connected to the wrong chambers. The babies look blue because there is insufficient oxygen circulating in their bodies.
The Mustard Procedure allows total correction of transposition of the great vessels. The procedure employs a baffle to direct oxygenated pulmonary venous return into the right atrium and thence into the right ventricle which is the pumping ventricle for the aorta and the systemic circulation. In other words, the Mustard Procedure restores the circulation but reverses the direction of the blood flow in the heart.
In a normal heart, de-oxygenated blood is pumped into the lungs via the right ventricle. Then it is distributed throughout the body via the left ventricle. In the Mustard procedure, blood is pumped to the lungs via the left ventricle and disseminated throughout the body via the right ventricle.
The Mustard procedure improved an 80% mortality rate in the first year of life to an 80% survival at age 20.
The Mustard procedure was largely replaced in the late 1970s by the Jatene procedure (arterial switch), in which the native arteries were switched back to normal flow, so that the RV (right ventricle) would be connected to the pulmonary artery and the LV (left ventricle) would be connected to the aorta. This surgery had not been possible prior to 1975 because of difficulty with re-implanting coronary arteries which perfuse the actual heart muscle iself (myocardium).