Cardiac bypass grafting is actually coronary bypass grafting, that is, when the heart coronary blood vessel disease is so serious that it is impossible to open the narrowed coronary blood vessels through drugs, stents, balloons and other methods, then it is necessary to build a blood vessel channel in the proximal and distal ports of the narrowed coronary artery. The new channel replaces the diseased blood vessel to provide an effective blood supply to the heart. This channel is like building a bridge over the narrowed blood vessel for the blood to pass through and flow, which is why it is figuratively called a bypass. When performing a cardiac bypass surgery, the vessel channel to be constructed needs to be chosen from the patient’s own blood vessels, such as the saphenous vein that intercepts the patient’s lower extremities, or the internal thoracic artery, which makes the surgery more difficult and demanding than coronary intervention.