Abstract
THE RECOGNITION of a physiological "demand" for collateral arteries by the coronary arterial system is becoming of practical clinical importance, because of the recent demonstration of collateral channels to coronary arteries in patients after the Vineberg internal mammary implantation,1, 2 and after implantation of a pedicle containing the internal mammary artery, vein, adjacent connective tissue, and muscle in an incision in the left ventricular wall.3 The fact that collateral arterial channels can be expected to develop only to an area of tissue with inadequate arterial supply is well established, and operations designed to cause collateral channels to develop to coronary arteries logically should be performed only on patients who have this situation in an accessible portion of the myocardium. Experiments have been performed in animals to obtain basic information that could be used in establishing reasonable clinical criteria for the use of the procedure in humans.4,