1, anticoagulation therapy for VTE – early, adequate and sufficient course is the key In anticoagulation therapy for VTE, early, adequate and sufficient course is the key. Firstly, as long as there is no contraindication, anticoagulation therapy should be given at the first time when VTE is detected. Early and adequate anticoagulation is an important measure to rapidly relieve symptoms and reduce recurrence of VTE. Secondly, anticoagulation therapy should be given in adequate courses for both symptomatic VTE and asymptomatic VTE to reduce the recurrence of VTE. For VTE caused by transient factors, anticoagulation therapy needs to reach 3 months. In contrast, for VTE of unknown origin, the patient’s risk-benefit ratio needs to be reassessed after 3 months of anticoagulation therapy to decide whether to continue anticoagulation. Among the patients with low risk of bleeding and low burden of anticoagulation monitoring, a longer duration of anticoagulation is recommended. For the first occurrence of peripheral DVT of unknown origin, 3 months of anticoagulation is sufficient, whereas for recurrent DVT, longer-term anticoagulation is required. Patients with VTE in combination with tumors require lifelong anticoagulation or until the tumor is completely cured, and anticoagulation with low-molecular heparin rather than vitamin K antagonists is recommended for the first 3 to 6 months because the former significantly reduces the rate of VTE recurrence and the risk of bleeding. 2. Prevention strategies for VTE after obstetrical and gynecological surgery and orthopedic surgery About 80% of pulmonary embolisms have emboli originating from the lower extremity or pelvic veins, and obstetrical and gynecological surgery and orthopedic surgery are the two types of surgery most likely to cause lower extremity or pelvic vein thrombosis. If no preventive measures are taken, the chance of DVT in patients undergoing major obstetrical and gynecological surgery is 15%-40%, which is a medium-risk patient for VTE, while the chance of DVT in patients undergoing hip or knee replacement is as high as 40%-60%, and the chance of DVT in patients undergoing compound trauma is even 40%-80%, which is a high-risk patient for VTE. VTE is one of the common and serious complications after surgery, and it is also one of the important causes of prolonged hospitalization and increased risk of death, so how to prevent VTE is a big problem for general hospitals. In general, for patients with deep vein thrombosis with risk of pulmonary embolism, existing pulmonary embolism, and contraindications to anticoagulation therapy, in order to prevent lethal pulmonary embolism caused by thrombus dislodgement, inferior vena cava filter implantation can be used, which can effectively prevent acute pulmonary embolism, but of course, this requires strict control of indications and prevention of the resulting complications. Nowadays, there are mainly two types of vena cava filters for clinical application, permanent and temporary, while a patient of advanced age or advanced tumor with recurrent VTE can choose permanent filter implantation, while for younger patients and some VTE patients with temporary high-risk factors (such as severe trauma, major surgery, postpartum, etc.), or patients with acute deep vein thrombosis but needing other surgeries (iliac, bone and joint Patients with dangerous venous thrombosis in patients undergoing surgery, gynecological surgery, rectal or retroperitoneal tumors, etc.) should opt for temporary vena cava filter implantation, which has the great advantage of preventing life-threatening acute pulmonary embolism during the risk period and of removing the vena cava filter after the risk period to avoid permanent retention in the body. In recent years, we have recommended the use of temporary filters for high-risk patients with indications based on strict control of the indications, and have achieved excellent results, with some filters intercepting large pieces of thrombus and saving patients’ lives. For high-risk patients in the perioperative period, comprehensive preventive measures should also be taken, and early postoperative bed activity is one of the most important measures to prevent VTE. Whether it is a major basic surgical procedure, obstetrical and gynecological surgery or orthopedic surgery, the early postoperative movement of patients out of bed or in bed is emphasized as much as possible, and foot dorsiflexion and plantarflexion exercises can promote venous return by using the calf muscle pump. Gradient compression stockings, plantar venous pumps, and mechanical VTE prophylaxis do not increase the risk of bleeding, but they are not a complete substitute for anticoagulation. Prophylactic anticoagulation should be routinely initiated preoperatively until the patient is ready to be ambulatory after surgery. If the patient has a combination of risk factors for VTE, such as a combination of malignancy and a previous history of VTE, prophylactic anticoagulation is recommended until discharge, even up to 28 days after surgery. Advanced age, vascular injury, limb braking, stagnant blood flow and hypercoagulation are important reasons why patients undergoing major orthopedic surgery are prone to VTE. Patients undergoing total hip replacement, total knee replacement, and hip fracture surgery are at high risk for VTE, and routine anticoagulation with low-molecular heparin, sodium sulforaphane, or warfarin is recommended to prevent VTE. aspirin, dextran, gradient compression stockings, or a plantar IV pump alone are not recommended as measures to prevent VTE. VFP or IPC may be taken to prevent VTE in patients at high risk of bleeding, and once they have passed the period of high risk of bleeding, additional pharmacologic anticoagulation is recommended. Prophylactic anticoagulation with low-molecular heparin is recommended in patients undergoing knee arthroscopy with combined high-risk factors for VTE. Low-molecular heparin anticoagulation is recommended to be added 12 hours before or 12-24 hours after major orthopedic surgery, and sulforaphane sodium anticoagulation is recommended to be added 6-8 hours after surgery or to be started the next day. The duration of anticoagulation therapy needs to reach at least 10 days postoperatively and needs to be extended to 35 days if necessary. 3. Outlook VTE is a common vascular disease that is more harmful and one of the common inpatient complications. Clinicians have been exploring and reacquainting themselves with the treatment and prevention of VTE for several years. The increasing evidence-based medical evidence provides more and more arguments and support for VTE prevention and treatment measures, and the emergence of new antithrombotic drugs has injected new energy into the prevention and treatment of VTE. However, there are many clinical issues that still await further understanding. For example, how to establish a set of early warning and prevention and response system for VTE disease for general hospitals, how to standardize VTE treatment measures in primary hospitals, and how to improve the treatment level; how to view the status of thrombolytic therapy in VTE treatment, what drug strategy should be adopted for rt-PA for lower limb DVT thrombolysis, what are the differences in efficacy and safety between pulmonary artery cannulation thrombolysis and trans-peripheral vein thrombolysis, and what are the differences in efficacy and safety between new anticoagulant drugs. What are the gaps in efficacy and safety between pulmonary artery cannulation and peripheral vein thrombolysis, the experience and data accumulation of new anticoagulants in VTE treatment, etc., all need more clinical studies to confirm. “This will be the attitude and voice of every clinician.