1. Surgery for coronary artery disease is the primary and most effective treatment for coronary artery disease. However, the excessively long surgical incision is a deterrent. Minimally invasive coronary artery bypass surgery replaces the conventional median sternotomy incision with a parasternal or open incision, which greatly reduces the length of the incision and thus reduces postoperative pain. Stanford University pioneered the establishment of extracorporeal circulation via femoral artery and vein puncture, followed by several small holes in the chest wall, insertion of a thoracoscope and surgical instruments, and performing the coronary artery bypass graft on a fluoroscopic television screen. To increase the accuracy of the procedure, surgeons can wear three-dimensional glasses as if they were there, thus reducing surgical errors. In addition, medical devices related to minimally invasive cardiac surgery have emerged. For example, to reduce the number of saphenous vein incisions in the lower extremities, endoscopic stripping of the saphenous vein is used, leaving only a few lcm-long incisions in the patient’s leg. Various different types of thoracic retractors, intrathoracic artery pulling hooks, and mechanical. Female stabilizers are also used in clinical practice. In addition there are still various non-penetrating automatic vascular anastomoses, Excimer laser vascular anastomosis are under investigation. Minimally invasive bypass surgery has the advantages of reducing surgical trauma, shortening hospitalization time and reducing medical costs. The indications for surgery include: ① Single lesion of the left anterior descending branch, especially severe proximal stenosis or complete occlusion, which is not suitable for coronary artery balloon dilation. ②Recurrence of stenosis after coronary balloon dilation or stenting. ③Patients with multiple coronary artery lesions, with renal failure, diffuse peripheral vascular lesions, advanced age, respiratory insufficiency, and patients with greater risk of extracorporeal circulation surgery, may also be considered for coronary artery bypass grafting under non-extracorporeal circulation. ④Patients with occlusion of the vascular bridge after coronary artery bypass grafting and need to be treated with another bypass surgery. ⑤ Minimally invasive surgery can be used with PTCA or stenting to treat multiple vascular lesions. Anatomically, the more desirable vascular conditions are-. Vascular diameter greater than 2 mm, proximal occlusion but good distal side branch vascularity, no calcification, hypoplastic left ventricle, thin chest wall and wide intercostal space, the procedure is easier to perform. Relative contraindications are patients with anterior descending branches traveling in the myocardium, extensive calcification, diameter less than 1.5 mm, severe pulmonary hypertension, and extreme left ventricular enlargement. 3. Surgical methods Minimally invasive methods are subdivided into non-extracorporeal methods (off-pump or beating heart), small-incision direct-view methods (mid CABG), window pathways and percutaneous extracorporeal circulation methods (port-access), and the various methods are described below. Endotracheal intubation for general anesthesia with double or single lung breathing. Prior to coronary artery block, anesthesia can be deepened while intravenous beta-blockers (esmolol, tretinoin) or calcium channel blockers (thiodiazepine, isoptin) are administered to reduce left ventricular systolic office, lower blood pressure, and slow down heart rate to facilitate surgical operation. Routine electrocardiographic ST-segment monitoring and hemodynamic monitoring, and continuous monitoring of ventricular wall motion function by esophageal ultrasound. (1) Surgery under non-extracorporeal circulation: supine position, median sternotomy incision, stripping the internal thoracic artery under direct vision from the beginning to the 6th intercostal space. Heparinize 1 mg/kg before dissection, and inject isoptin or poppy bases into the internal thoracic artery to prevent vasospasm. The pericardium is incised and the pericardial sutures are drawn towards the sternal stalk and scapula to fix it, while the heart is pulled towards the edge of the incision to facilitate manipulation. Examine the anterior descending branch, and if there is severe calcification or it is deeply embedded in the myocardium, the operation should be changed to under extracorporeal circulation. After everything is prepared, the ischemic test or preconditioning is performed first. The coronary artery J is temporarily blocked for 5 minutes, and if there is little change in blood pressure and heart rate, the patient is proven to tolerate the temporary ischemia. After 5 minutes of open reperfusion, coronary flow can be formally blocked and anastomosis of the internal thoracic artery to the anterior descending branch can be performed. It is very difficult to perform the vascular anastomosis with the heart beating. Measures must be taken – to keep the beating heart relatively immobilized; by the following methods: ① Use of beta-blockers or calcium channel blockers to reduce myocardial contractility and slow – the heart rate. (ii) Intravenous injection of high-dose adenosine several times to keep the heart at rest temporarily and facilitate surgical operation. ③Fixing the myocardial tissue around the coronary artery to the edge of the incision with traction thread or fixing the sutures blocking the coronary artery to both sides of the incision can help stabilize the coronary artery. (iv) Local fixation of the machine occipital I raw heart: the epicardial tissue around the coronary artery is fixed with Utrecht (octopus) apparatus (including fixation suction device) to keep the heart in a relatively stable state. Ischemic pretesting can be performed once the coronary artery is stabilized. The anterior descending branch is dissected 4-5 mm, and the internal thoracic artery is anastomosed to the anterior descending branch with 8-0 polypropylene sutures. In the case of multivessel lesions with sequential anastomosis, the apex can be laterally anastomosed to the gyral branch, then laterally to the oblique branch, and finally to the anterior descending branch. In case of sequential anastomosis of the internal thoracic artery, the oblique branch should be anastomosed laterally to open the perfused myocardium, and then the anterior descending branch should be anastomosed end to end. After completing the distal anastomosis, the distal and proximal coronary artery blocking sutures should be opened first, and then the intrathoracic artery blocking clips should be opened. In case of multi-vessel lesions or grafting of the saphenous vein, the ascending aorta can be partially blocked, perforated, and then closed with continuous 6-0 polypropylene sutures, thus completing the proximal anastomosis. The pericardial cavity and thoracic cavity are placed for drainage, routine hemostasis, and chest closure.