Although CABG is also called coronary artery bypass grafting, the material used to build this bridge is not ordinary steel, cement and concrete, nor any other artificial or biological material. So far, no material has been discovered or manufactured that can be used in the human body without toxicity, side effects, or rejection, but also to ensure that the blood does not clot on its surface and can keep the blood flowing smoothly for a long time. The most commonly used bridging material in clinical practice is still the patient’s own blood vessels. Both a blood vessel from another part of the body is taken off and connected between the ascending aorta and the coronary artery. The original function of this vessel is compensated by other vessels in its vicinity through collateral circulation. Although there is some damage to the site where the vessel was removed, its function is not affected by the compensation of the collateral circulation. In order to maintain the function of the heart and ensure life, we have to throw away the pawn and save the whole body for the heart. During coronary angiography, you should try to relax and never be nervous to avoid complications such as acute myocardial infarction due to coronary artery spasm caused by mental stress. After the coronary angiography is finished, we should compress the puncture site and rest in bed for 24 hours to prevent complications such as bleeding from the puncture site. The saphenous vein is a vein that travels on the inside of the lower extremity, close to the inner skin. The saphenous vein starts from the medial side of the ankle, travels upward, and injects into the femoral vein at the root of the thigh. The main function of the saphenous vein is to direct venous blood from the skin and subcutaneous fat of the medial lower extremity back to the femoral vein. Therefore, when the saphenous vein is removed, the only damage to the body is a long skin incision and scar and superficial obstruction of venous return, which is compensated by the collateral circulation and does not cause any sequelae. The diameter of the saphenous vein is about 3-5 mm, which is just the right thickness to match the coronary artery and ensure sufficient blood flow after the bypass surgery. Also, the saphenous vein is long enough to accommodate multiple coronary artery lesions that require multiple bypasses. Although a long scar will be left after acquiring the saphenous vein, it is after all a superficial injury and is not harmful to the whole body, so it is not very traumatic. Also, the saphenous vein is located on the surface of the body and is very easy to access. An experienced physician can prepare a saphenous vein in a few minutes. It is very useful especially in emergency or resuscitation procedures. In addition, because it is a vein, it does not spasm and affect blood flow, ensuring that the corresponding coronary artery will have an adequate blood supply after surgery. Therefore, the saphenous vein is the first and currently the most used and popular bypass material in clinical practice. The greatest disadvantage of the saphenous vein is its poor long-term patency. This is due to the thin wall of the vein and the low pressure of the blood flowing through the vein in physiological conditions. After the CABG procedure, the saphenous vein that is grafted over the coronary artery is flowing with high pressure arterial blood. As a result, the endothelial cells of the saphenous vein are easily damaged by the impact of high-pressure arterial blood flow, and calcium, lipids, platelets and other substances tend to accumulate at the damaged area, causing atherosclerosis in the grafted saphenous vein and resulting in stenosis of the grafted vessel. The approach to its prevention is the same as the overall prevention of coronary heart disease. Although CABG is also called coronary artery bypass grafting, the material used to build this bridge is not ordinary steel, cement and concrete, nor any other artificial or biological material. This is because so far, no substance has been discovered or manufactured that can be used in the human body without toxicity, side effects, or rejection, but also to ensure that blood does not clot on its surface and that blood flow can be maintained for a long time. The most commonly used bridging material in clinical practice is still the patient’s own blood vessels. Both a blood vessel from another part of the body is taken off and connected between the ascending aorta and the coronary artery. The original function of this vessel is compensated by other vessels in its vicinity through collateral circulation. Although there is some damage to the site where the vessel was removed, its function is not affected by the compensation of the collateral circulation. In order to maintain the function of the heart and ensure life, we have to throw away the pawn and save the whole body for the heart. During coronary angiography, you should try to relax and never be nervous to avoid complications such as acute myocardial infarction due to coronary artery spasm caused by mental stress. After the coronary angiogram, the puncture site should be compressed and rested in bed for 24 hours to prevent complications such as bleeding from the puncture site. 2, Internal mammary artery The internal mammary artery is also called the internal thoracic artery (ITA). The internal mammary artery originates from the subclavian artery and travels vertically downward in the thorax along the outer edge of the sternum at 1-1.5 cm, terminating at the 6th rib cartilage and dividing into two terminal branches, the phrenic artery and the superior abdominal wall artery. The internal mammary artery vasculature is approximately 20 cm long, longer in males than in females, and slightly longer on the left than on the right. The length of the internal mammary artery vasculature depends on the shape of the thorax; if the thorax is long, the internal mammary artery is also long, and if the thorax is short, the internal mammary artery is relatively short. The diameter of the internal mammary artery is about 1.5-2 mm at the bifurcation, and is slightly thicker in men than in women. The internal mammary artery is accompanied by the internal mammary vein on both sides of the internal mammary artery. (1) Who should receive an internal mammary artery-coronary artery bypass graft? The left internal mammary artery-anterior descending branch bypass graft is currently the most effective procedure for myocardial revascularization with the highest long-term patency rate. Therefore, except for special circumstances and contraindications, the left internal mammary artery should be preferred for all stenoses of the anterior descending branch of the coronary artery requiring bypass graft surgery. The left internal mammary artery is also indicated for patients with stenosis of the diagonal or left circumflex branches, either alone or in combination with the right internal mammary artery or other vessels. The right internal mammary artery can be used as a bypass graft for the right coronary artery, the anterior descending branch of the left coronary artery, and the left circumflex branch. The long-term results of coronary artery bypass grafting with bilateral internal mammary arteries are better than those with unilateral internal mammary arteries, and coronary artery bypass grafting with all arterial vessels significantly reduces the reoperation rate. The right internal mammary artery can be used together with the left internal mammary artery in younger patients (<55 years) or in combination with other arterial grafts such as the right gastric omental artery and radial artery for multi-vessel total arterialized coronary artery bypass grafting. (2) Which patients cannot undergo internal mammary artery-coronary artery bypass grafting? Absolute contraindications to internal mammary artery-coronary artery bypass grafting are stenosis at the beginning of the internal mammary artery, sclerotic stenosis or occlusion of the subclavian artery, atherosclerotic stenosis of the internal mammary artery itself (the incidence of which is <1% in patients with coronary artery disease), aneurysm of the descending aortic arch and intimal tear entrapment aneurysm, trauma to the chest and history of trauma to the internal mammary artery or surgery such as thoracoplasty. Relative contraindications include excessive obesity, severe pulmonary insufficiency, and acute surgery. The use of unilateral internal mammary artery, whether left or right, is not affected in diabetic patients; however, the use of bilateral internal mammary artery should be carefully considered because of the risk of sternal doctrine, mediastinal or incisional infection, and is generally not used. 3.Radial artery The radial artery is an arterial blood vessel supplying blood to the lateral forearm and hand. At 1 cm below the elbow joint, the brachial artery is divided into two branches: the ulnar artery and the radial artery. The radial artery travels downward in front of the forearm and gives off many branches, eventually giving off branches of the superficial palmar branch of the radial artery, the myocardial branch, the radial reactive artery, and the deep palmar branch at the wrist to form the superficial palmar arch and the deep palmar arch, which supply nutrition to the hand The radial artery has the advantages of sufficient length, moderate caliber, and easy access. The length of the radial artery can meet the needs of any coronary artery bypass graft, and it is an arterial structure with good long-term properties, making it an excellent material for coronary artery bypass graft. The length of the radial artery in Chinese is about 18.5±2.85 cm; the distal internal diameter is 2.45±0.32 mm . Because the blood supply to the forearm and hand after the radial artery is removed is compensated by the ulnar artery, the collateral circulation of the ulnar artery needs to be tested to observe whether the collateral circulation is good before the radial artery is removed. The method is to press both the radial and ulnar arteries, make a fist movement with the fingers, then unfold the fingers and release the ulnar artery to observe the restoration of blood supply to the hand, and the normal restoration time is within 10 seconds. This method is called the Allen test. Usually the Allen test is performed for 6 seconds to determine the collateral circulation of the ulnar artery. If the Allen test is within 6 seconds, the radial artery can be safely taken without causing ischemia in the fingers and forearm. Although the radial artery is an excellent material for coronary artery bypass graft, it is not suitable for all patients, such as violinists, pianists, writers, and painters who are engaged in delicate work with high functional requirements of the hand, and should be carefully considered on whether to take the radial artery. 4.Gastric omental right artery Gastric omental right artery for coronary artery recanalization began in 1984, has nearly 20 years of history, near and long term patency rate are better, is considered a better material for coronary artery bypass. Normally there are four arteries providing blood supply to the stomach, namely the left gastric artery, the right gastric artery, the left gastric retinal artery and the right gastric retinal artery, so it is said that the blood supply to the stomach is very rich. Moreover, the branches of each vessel anastomose extensively with each other in the submucosa of the stomach, forming a submucosal plexus and a very rich collateral circulation. In general, the blood supply to the stomach can be ensured without gastric ischemia by preserving any one of the four arteries. Although the right gastri-retinal artery is a better material for coronary artery bypass, obtaining the right gastri-retinal artery requires opening the abdominal cavity and postoperative fasting, which is very traumatic for the patient and increases the surgical risk with a long postoperative recovery time. Therefore, the right gastric omental artery is not commonly used in coronary artery bypass surgery. 5. Other vessels (inferior abdominal wall artery, ulnar artery, small saphenous vein, artificial vessels) Besides the above four commonly used vessels, surgeons occasionally use inferior abdominal wall artery, small saphenous vein, ulnar artery, cephalic vein and artificial vessels for coronary artery bypass surgery. In general, these vessels are not as good as the above 4 types of vessels. Although the inferior abdominal wall artery and ulnar artery are arterial materials, their diameters are too thin to fully meet the blood supply needs of coronary arteries; the small saphenous vein and cephalic vein are of poor quality, and the long-term patency rate after coronary artery bypass surgery is low; although artificial vessels are not limited by the material taken, they are prone to form thrombus in the lumen and affect the efficacy of surgery. Therefore, these materials are not commonly used, but only when there are no good vessels available, and these materials are used as a last resort.