Biologic Valves

D R. PROCTOR HARVEY, Dr. Braunwald, Ladies and Gentlemen, I am deeply conscious of the honor you have bestowed upon me as a surgeon in asking me to give this lecture. Although modesty is not a quality with which surgeons are generally overendowed, I would like to accept it as a tribute to my colleagues both medical and surgical who work with me at Guy's and National Heart Hospitals in London. In fact, teamwork is the feature which has characterized modern cardiac surgery and distinguishes it from that of our predecessors. I am sure I speak for my surgical colleagues on both sides of the Atlantic when I say that ours is a unique and I am sure coveted relationship, where cardiologists and cardiac surgeons work together in a truly interdependent manner fulfilling an ideal which in other branches of our profession is often a meaningless and hollow gesture of clinical cooperation. When I undertook to give this lecture, I did so feeling I was on familiar ground but I did not appreciate the considerable task I would encounter in trying to make a brief assessment of biologic valves today. For instance, far from assessing world trends, I quickly found that my own thoughts were in need of clarification. Hoping to draw inspiration from my colleagues by comparing results I found this also fraught with problems.