First of all, necessary preoperative tests are performed, including blood tests, ECG, chest X-ray, cardiac ultrasound, carotid ultrasound and coronary angiography, and other special tests if necessary. Secondly, oral anticoagulants, such as Bolivar, need to be stopped before surgery and wait for a certain period of time. Wait for these drugs to be metabolized and eliminated in the body so as not to increase the risk of bleeding, with the exception of emergency surgery. It is also necessary to reduce activity, rest in bed, avoid mental tension, emotional excitement, etc. Do not eat too much to force bowel movements, keep bowel movements unobstructed, and if necessary, medication can assist in bowel movements. Also, in order to prevent postoperative respiratory complications, you should quit smoking, practice deep breathing and coughing movements, and avoid catching a cold. Get a good night’s sleep and take sleeping pills if necessary. It is very important to tell your supervising physician if you have had other surgeries or taken other medications before, and if you have had other diseases, such as glaucoma, peptic ulcers, severe hemorrhoids, brain embolism, etc.!