John Kirklin and his team at Mayo Clinic adapted and improved Gibbon's design until achieving a reproducible series of successful open-heart surgeries starting in March 1955. That step — turning the heroic experiment into practice with consistent results — is what transforms a technology into a specialty. Kirklin published detailed results, facilitated the transmission of the technique, and redefined the horizon of all later cardiac surgery. In the surgical tree it is the node from which coronary bypass, transplantation, and the artificial heart branch off.