Favaloro was born in La Plata, province of Buenos Aires, Argentina. He studied medicine at the National University of La Plata. He became interested in developments in cardiovascular intervention, and developed an enthusiasm for thoracic surgery. Professor Mainetti pointed him in the direction of the Cleveland Clinic.

At the beginning of 1967, Favaloro began to consider the possibility of using the saphenous vein in coronary surgery. He put his ideas into practice for the first time in May of that year. The basic principle was to bypass a diseased (obstructed) segment in a coronary artery in order to deliver blood flow distally. The standardization of this technique, called bypass or transmyocardial revascularization surgery, was the fundamental work of his career, and ensured that his prestige would transcend the limits of his country, as the procedure radically changed the treatment of coronary disease.

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