It is a relatively more problematic issue if a patient needs to undergo surgery while on warfarin anticoagulation therapy, as anticoagulation may lead to increased bleeding at the surgical site. The solution is to stop warfarin for a few days before surgery and to replace the therapy with heparin. Because heparin has a short half-life, stopping it before surgery allows the patient’s coagulation to recover, reducing the risk of surgical bleeding. However, this carries the risk of leaving the patient with a period without anticoagulant therapy with warfarin, and the anticoagulant effect of heparin is not a complete substitute for the equivalent of warfarin. Therefore, it is important to carefully assess before surgery whether the patient is at greater risk from postoperative bleeding or the patient is at greater risk from warfarin-free anticoagulation. The tolerance for postoperative bleeding varies from site to site. Also, the ease of surgical hemostasis varies. For example, small surgeries such as tooth extraction and excision of skin lipomas with small surgical invasions and good visualization of the surgical site can be performed with effective compression hemostasis, and even if the postoperative bleeding is slightly more frequent, there will not be too much of a problem. Intracranial surgery is different. Brain tissue is rich in blood vessels, the surgical field is poorly revealed, hemostasis is relatively difficult, and if there is still bleeding at the surgical site after surgery, it can lead to an intracranial hematoma, which can compress the brain tissue. Therefore, heparin replacement therapy is not necessary at all for minor surgeries (especially outpatient surgeries) in areas such as tooth extraction, skin, and fingers, while caution must be exercised for surgeries in critical areas such as the cranium and spine. If heparin replacement therapy is performed, the first important thing is to check the INR daily from the time warfarin is stopped until the time after surgery when warfarin is taken to bring the anticoagulation intensity up to the required level. warfarin is usually stopped 4-5 days before surgery, during which time 5,000 units of low molecular heparin are injected subcutaneously over a 12-hour period, and is stopped 12 hours before surgery. After wound bleeding stops after surgery, low molecular heparin is started immediately at the same dosage and in the same way as before, and warfarin is started at the same time, and heparin is discontinued until the INR reaches the prescribed anticoagulation intensity (usually 3-5 days). In case of emergency surgery, vitamin K1 can be given intravenously as early as possible before surgery and INR values can reach the normal range within 12-24 hours. The right dose of vitamin K1 is one that can rapidly reduce INR values to the normal range without causing resistance to postoperative warfarin anticoagulation (if the patient has too much vitamin K in his body, INR values will not rise immediately after taking warfarin). Requirement of the operator intraoperative hemostasis should be very careful. In our clinical work, we often have some patients undergoing emergency cardiac surgery due to prosthetic mechanical valve dysfunction, without stopping warfarin before surgery, the surgery is a second operation, which needs to saw open the sternum, the tissue adhesion is serious, and the trauma is large. However, as long as the hemostasis is complete, the postoperative bleeding is not worse than that of a routine first surgery.