The core of coronary surgery technique is to select and find the correct target vessel and make a good distal anastomosis at the appropriate location distal to the lesion. High quality vascular anastomosis is the most important condition to ensure the immediate and long term patency rate. 1.Distal anastomosis of coronary artery: It is important to explore the coronary artery, mark the location of the lesion or free the distal end of the lesion, and decide the branch of the coronary artery to be anastomosed and its location. Dissect the epicardium and fat, and pay attention to avoid damaging the accompanying veins when freeing the coronary artery. Anastomosis should be performed at the distal end of the coronary lesion with an internal lumen diameter greater than 1.5 mm, and generally not at an internal diameter of less than 1 mm. The right coronary artery bifurcation is often diseased and should be anastomosed on the posterior descending branch, unless the distal end is too thin and generally not anastomosed to the main stem. The coronary artery incision is 3-5 mm long, at least twice the internal diameter of the artery and as long as the diameter of the vein. If there is a lesion in the right coronary artery trunk it should be anastomosed on the trunk, i.e. any desired location before the bifurcation of the posterior left ventricular branch of the right coronary artery from the posterior descending branch. The anterior wall of the coronary artery is incised without damaging the posterior wall, and the ends of the opening are cut with angled scissors along the longitudinal axis until the incision is of appropriate size, with the edges of the incision as neat as possible. The proximal end of the saphenous vein is cut into an oblique opening of the appropriate size and closed with continuous external sutures using 7-0 Prolene sutures. The suture should not be too diluted to avoid a purse-string effect and narrowing of the anastomosis, especially at the toe (toe), where the key sutures should be precisely positioned. The suture can generally start at the heel (heel) and end at the heel (hee1), but in anastomosis of the right coronary artery it can start at the toe (toe) first for a better anastomosis. The anastomosis should be careful, tight and without bleeding, and the anastomosis should be open. Before tying the knot, the bridge should be exhausted, and the anastomosis should be checked for blood leakage, and the length of the bridge and the angle of the anastomosis should be appropriate. If sequential anastomosis is needed, the distal end should be anastomosed first, and then the anterior wall of the coronary artery and vein to be anastomosed should be cut, and lateral or diagonal anastomosis should be chosen according to the different positions. The general order of bypass is to do the dorsal side of the heart first, i.e. the left marginal branch, then the right coronary artery, and finally the anterior descending branch. If the anterior descending branch is done first and then other anastomoses are done, the anterior descending branch may be damaged; however, if non-extracorporeal circulation is used, the left ventricular ischemic area may be addressed first, i.e., after the anterior descending branch is done, then the marginal branch or right coronary artery is done. ”Y” shaped bridge anastomosis: A naturally occurring “Y” shaped vein may be used, or two segments of vein may be used to anastomose together in a “Y” shape with only a proximal anastomosis. When doing the “Y” anastomosis, the distal end should be done first, and then the proximal end should be anastomosed after the distal anastomosis of the two bridges. If two veins are used, the distal end should also be anastomosed first, then one of the bridges should be anastomosed on the ascending aorta, and the proximal end of the other vein should be anastomosed on the previous vein bridge. The “Y” shaped bridge may have a similar patency rate as the sequential bridge. 2. Anastomosis of internal mammary artery: cut off the distal end of the internal mammary artery, check the flow and pressure and branches for bleeding, block the proximal end with pugilistic forceps, free the distal internal mammary artery to the appropriate caliber, select the right direction, and cut it longitudinally. Generally, the left internal mammary artery is anastomosed with the anterior descending branch, so the distal anterior descending branch lesion should be freed first. The anastomosis can be performed with 7-0 Prolene suture or 8-0 Prolene suture, and the proximal end of the anastomosis (heel) is sutured first, followed by the distal end (toe). After the last suture, reduce the perfusion flow and pressure, open the pug clamp, and tie the knot to check for bleeding. If a sequential anastomosis is done, the diagonal branch can be anastomosed first, followed by the anterior descending branch. A “T” shaped anastomosis can also be done during small incision surgery. 3.Proximal anastomosis of coronary artery: After the upper lateral wall clamp, choose the location of the proximal anastomosis, pay attention to the artery with or without calcification, cut the outer membrane, first use a sharp knife to cut the appropriate opening (3~4mm long), then use a 4.0~4.8mm punch to punch the hole. The vein length was measured and the proximal angle was cut appropriately, and the vein bridge was blocked with pugilistic forceps to prevent back bleeding from affecting the operative field. Continuous sutures with 5-0 or 6-0 Prolene thread can be used to suspend the proximal end of the vein first, and after 4~5 stitches on the opposite side of the anastomosis, the vein sutures are lifted tightly so that the vein is placed over the anastomosis to continue the suturing. This can be done first on the right side and then on the left side. After completion, flow is reduced and the ascending aorta is deflated before tying the knot and removing the lateral wall clamp. Use a syringe and 26-gauge needle to vent the vein bridge and open the pug clamp on the bridge. If the aorta is calcified and only one anastomosis can be made proximally, the proximal end of the venous bridge can be anastomosed to the root of the other venous bridge, i.e., the bridge is bypassed. If the root is too severely calcified to be anastomosed, an anastomosis on the innominate artery may be considered. If the unnamed artery is also diseased, an artificial vessel is applied to replace the ascending aorta and the vein is anastomosed to the artificial vessel. This can also be done with complete blockage of the ascending aorta. If the proximal anastomosis is done with complete block, the proximal end of the vein may not need to be placed with a pug clamp, but the ascending aorta should be fully ventilated before opening. It is also possible to use a proximal anastomosis without blocking the ascending aorta.