Coronary heart disease has become the leading cause of death in developed to western countries, although the incidence of coronary heart disease in our country is lower than abroad, but with the improvement of our people’s living standard in recent years, the incidence of coronary heart disease has increased year by year, has amounted to 154/100,000/year, men are higher than women, higher than the rural areas of the city, the north is higher than the south, the total number of about 43 million, and it has become a threat to the people’s life and health of the most serious diseases. Relevant studies have found that the occurrence of angina, arrhythmia and myocardial infarction and other cardiac events in patients not treated with bypass surgery amounted to more than 40%, while the incidence of cardiac in patients treated with surgery was less than 2%. There were 23% deaths in patients treated medically for 40 months, compared with 0% deaths in patients treated surgically for 40 months. Therefore, it is necessary to increase the understanding of coronary heart disease to prevent its occurrence or to strive for early diagnosis and early treatment of coronary heart disease. The heart and blood vessels form a closed vascular system in the human body, in which the blood circulates constantly, bringing nutrients and oxygen to the various organs of the human body and maintaining the survival and normal activities of the human body. The heart is the driving system, i.e. the power pump, and the blood vessels are the pipeline system, i.e. the transportation channel. Of course, the heart also needs nutrients and oxygen to maintain normal work. The transportation channels that supply the heart itself are called coronary arteries. The so-called coronary heart disease due to a variety of reasons that lead to the heart’s own transport channel congestion or blockage, that is, the coronary arteries are narrowed or occluded and caused by the heart itself insufficient blood supply of a class of diseases, so also known as ischemic heart disease. Coronary artery stenosis or occlusion is usually caused by lipid metabolism disorders in the human body, which leads to plaque deposition in the inner lining of the arteries, resulting in thickening, hardening, and decreasing the elasticity of the arterial walls. According to the degree of coronary artery stenosis and occlusion, coronary heart disease can be divided into four levels: due to coronary artery stenosis caused by the reduction of the diameter of the lumen of the blood vessel up to 1/4 for mild; reduced by 1/4 to 1/2 for moderate; reduced by 1/2 to 3/4 for severe; lumen stenosis of more than 3/4 for super-severe. Generally, mild and moderate lesions do not cause obvious reduction of coronary blood flow, and often have no obvious clinical manifestations. Stenosis above the severe degree is often directly related to the onset of coronary heart disease. However, there are also patients with mild coronary artery lesions due to the occurrence of lipid plaque rupture, bleeding, thrombosis blockage of coronary arteries, resulting in severe myocardial ischemia or infarction, and even patients with sudden death. The coronary arteries supplying blood to the heart are divided into left and right branches, and the left coronary artery is divided into the anterior descending branch and the rotary branch. The blood supply to the heart mainly depends on the three blood vessels, the anterior descending branch, the rotary branch and the right coronary artery. Once these three blood vessels are narrowed, which is often referred to as triple branch lesions in clinical practice, coronary artery bypass grafting, or bypass grafting for short, is usually required. Currently, there are three commonly used treatments for coronary artery disease: drug therapy, interventional therapy, and bypass surgery. The first two treatments belong to the category of internal medicine. The purpose of drug therapy for angina pectoris is to terminate and prevent angina attacks. The route of drug therapy: increase myocardial blood flow. Including dilation of coronary arteries, promote collateral circulation, slow down the heart rate and prolong the diastolic time so that the coronary artery perfusion time increased. Reduce myocardial oxygen consumption. This includes decreasing myocardial contractility, decreasing heart rate, and decreasing the anterior and posterior loads of contraction. Fixed stenosis of the coronary arteries and increased myocardial oxygen consumption as the main cause of angina pectoris, treatment to reduce myocardial oxygen consumption; coronary artery spasm occurs on the basis of angina pectoris, the treatment is to increase coronary blood flow. Drug treatment can only relieve angina, but it is difficult to improve the patient’s quality of life, and it is difficult to treat patients with severe coronary artery disease. Interventional therapy is often referred to as stenting, the advantage is that there is no need to open the chest, as long as the femoral artery from the thigh puncture can be completed (see Figure 1). The disadvantage is that many serious coronary artery lesions using interventional therapy is not effective, or even can not be carried out, which requires coronary artery bypass grafting surgery, commonly known as heart bypass surgery. Coronary artery stenosis of coronary heart disease is mostly segmental distribution and is mainly located in the near middle of the coronary artery, the distal part of the blood vessels are mostly normal, bypass surgery is to use the patient’s own saphenous vein or internal mammary artery in the aorta and the coronary artery between the narrowed coronary artery across the section of the coronary artery to take a vascular bridge, so that the blood is transported through the bridge to the ischemia! This “bridge” allows blood to be transported to the ischemic myocardial tissues in the same way that a bridge allows a highway to flow freely across a ravine or a river (see Figure 2). However, the material used is not reinforced concrete, but its own blood vessels, which can be the saphenous vein, internal mammary artery, right gastric omental artery, radial artery, submental artery, etc. Generally, the more commonly used are the saphenous vein, internal mammary artery, and radial artery. With saphenous vein bypass, the saphenous vein is removed from the upper leg or thigh and anastomosed to the distal coronary artery stenosis at one end and to the ascending aorta at the other end, or several side holes are made in one vein at the same time for lateral anastomosis with several coronary arteries, which is known as sequential bypass or serpentine bridge. Bypass of the saphenous vein has a worse long-term effect than arterial bypass, but the operation is relatively simple and less damaging, therefore, it is suitable for older patients. Bypass of the arterial vein is more damaging and technically demanding, and the operation is more difficult, but the long-term effect is better than that of the greater saphenous vein, and it is suitable for younger patients. In general, over 80 years old can use saphenous vein bypass alone, over 55 years old can consider all arterial bypass, other ages can use one internal mammary artery plus large saphenous vein. In addition, if bypass surgery is required in an acute myocardial infarction patient in an emergency, a venous bridge is often used because the goal is to restore blood supply to the infarcted myocardium as soon as possible. The procedure is usually performed under general anesthesia with hypothermia, extracorporeal circulation, and cardiac arrest. It usually takes 2-3 hours. Patients who cannot tolerate extracorporeal circulation, or those with suitable conditions, can also undergo non-stop bypass surgery without extracorporeal circulation and with the heart beating. Although non-stop surgery is theoretically superior to bypass surgery, the results of national and international clinical trials have not shown a significant difference in prognosis. The advantages of bypass surgery are high long-term patency rate of the bridging vessel and high long-term survival rate; the disadvantages are large surgical trauma, slightly longer hospitalization time, and a certain risk of complications and death.