What are the vascular embolic diseases? How to prevent it?

Thrombosis refers to the formation of blood clots in human blood vessels, and thrombosis refers to the process of forming blood clots in blood vessels. Thrombosis is an important protective mechanism to avoid excessive blood overflow when an individual encounters trauma. At the same time, there are factors that inhibit thrombosis in human body, which prevent unrestricted expansion of thrombus and abnormal thrombosis, that is, anticoagulant system. After the hemostasis of thrombus is completed, there is still a fibrinolytic mechanism in the body to remove thrombus, and fibrinolytic activity in the fibrinolytic activator/fibrinolytic inhibitor mediator. In this way, the two systems, hemostasis and anticoagulation, fibrinolysis and antifibrinolysis, interact and balance each other, ensuring that blood in human body can flow normally in blood vessels under normal physiological conditions, and neither thrombosis nor bleeding occurs. Thrombosis can be formed during trauma to stop bleeding, and it can be removed after hemostasis. Feng Xiangran, Department of Vascular Surgery, Shanghai Changhai Hospital, however, if the above mechanism is unbalanced and the thrombus blocks the official cavity too much, it will become a thrombotic disease. Thrombosis formed in blood vessels will fall along the direction of blood flow, and when it meets a blood vessel with a smaller diameter than thrombus, it will cause blood vessel blockage, that is, embolism. Because these two processes are interrelated, they are collectively referred to as thromboembolic diseases in clinic. The disease is the leading cause of death of human diseases at present. Thromboembolic diseases can occur at any age, but the incidence rate is the highest in the elderly. The main reasons are as follows: 1. Vascular wall injury. With the increase of age, there are different degrees of atherosclerosis and vascular endothelial damage in the blood vessels of the elderly, which promotes thrombosis. 2. Changes in platelets. The aggregation of platelets in the elderly increases with age, which is more likely to cause thrombosis than young people. 3. Blood viscosity increases. With the increase of age, the viscosity of blood in the blood vessels of the elderly also increases, which is easy to form thrombosis. 4. Changes in coagulation function. The elderly have different degrees of hypercoagulability and increased coagulation factors, so they are prone to thrombosis. Therefore, the elderly are the focus of prevention and treatment of thromboembolic diseases. Thrombosis can occur in any part of cardiovascular system, and physiological thrombosis mostly occurs outside blood vessels, which is a hemostatic response and protective mechanism to trauma. Pathological thrombosis mostly occurs in blood vessels, causing tissue ischemia or congestion, causing vascular events and even vascular death. Thromboembolic diseases mainly include atherosclerotic thrombosis, venous thromboembolism and peripheral arterial embolism. The disease is systemic. Coronary heart disease, cerebral infarction, renal artery stenosis, arteriosclerosis obliterans of lower limbs, deep venous thrombosis of lower limbs and pulmonary embolism are all manifestations of the disease in different blood vessels, so the prevention and treatment of the disease should also be systematic. 1. The occurrence of thromboembolic diseases 1. Arterial thrombosis mainly involves cardiovascular and cerebrovascular diseases and peripheral arteries. Thrombosis in these parts is mostly formed on the basis of the rupture of atherosclerotic plaques, that is, the injury of the inner wall of blood vessels leads to thrombosis, which seriously leads to myocardial infarction, cerebral infarction and acute ischemic necrosis of lower limbs. Therefore, atherosclerotic thrombosis is plaque rupture and thrombosis on the basis of atherosclerosis. Atherosclerotic thrombosis is related to risk factors. In addition to heredity, age and sex, many risk factors are closely related to lifestyle and are part of metabolic syndrome. Atherosclerotic thrombosis usually has many risk factors. The more risk factors, the greater the intensity or the longer the exposure time, the higher the incidence of vascular diseases and vascular events (myocardial infarction, cerebral infarction, vascular death). Atherosclerotic thrombosis usually involves multiple vascular beds, especially in the presence of diabetes; Vascular disease or event means that another blood vessel may have or will have similar problems; Lower extremity vascular diseases rarely directly lead to death, but lower extremity vascular diseases are predictive factors of myocardial infarction or cerebral infarction. To some extent, the formation of atherosclerotic thrombus can be prevented and treated. Acute arterial occlusion can lead to myocardial infarction, cerebral infarction and acute ischemia, necrosis or gangrene of lower limbs. Non-occlusive diseases are characterized by stable angina pectoris, chronic ischemic encephalopathy and claudication of both lower limbs. 2. Venous thromboembolism The main complication or consequence of deep venous thrombosis (DVT) is pulmonary embolism, both of which are collectively referred to as venous thromboembolism (VTE). The death caused by venous thromboembolism ranks third in the west after cardiovascular and cerebrovascular diseases and malignant tumors. In addition to injury leading to venous thrombosis, venous thrombosis is mostly related to slow blood flow and poor drainage. In addition, thrombosis factors in blood components, such as fibrinogen and abnormal protein C resistance, have greater influence on venous thrombosis than arterial system. Venous thromboembolism mostly occurs on the basis of major surgery/trauma, malignant tumor, serious disease, long-term immobilization/bed rest and congenital thrombophilia. Deep venous thrombosis leads to poor blood return, congestion and edema, and even local necrosis; In addition, deep venous thrombosis can be embolized to pulmonary artery along the blood flow, leading to pulmonary embolism and even death (fatal pulmonary embolism); After the occurrence of venous thromboembolism, many patients still have edema of lower limbs and/or limb malnutrition, which is called post-thrombotic syndrome and affects the quality of life of patients. Pulmonary embolism mostly occurs on the basis of deep vein thrombosis, especially in the proximal (popliteal vein and popliteal vein) deep vein thrombosis. If pulmonary embolism can't be diagnosed and treated in time and effectively, the mortality rate can be as high as 30%. Most deaths occur within 2 hours, and 1% dies within1hour. Many patients can't be saved. Therefore, prevention of deep vein thrombosis should start with pulmonary embolism. The prognosis of venous thromboembolism depends not only on reliable diagnosis and effective treatment in acute phase, but also on long-term treatment to prevent recurrence and post-thrombotic syndrome. 3. Peripheral arterial embolism Peripheral arterial embolism is most common in patients with atrial fibrillation, myocardial infarction and aortic aneurysm, and often leads to acute arterial ischemia, such as stroke, intestinal infarction and lower limb necrosis. Second, the diagnosis of thromboembolic diseases is mainly based on medical history, physical examination and auxiliary examinations, such as electrocardiogram, cardiac troponin, brain CT examination and vascular imaging examination. Modern noninvasive angiography is of great value in the diagnosis of thromboembolic diseases. For example, color Doppler ultrasound is sensitive and accurate in the diagnosis of carotid plaque and deep vein thrombosis of lower limbs. CTA and MRA can provide images of whole body blood vessels with the same accuracy as DSA. For arterial thrombotic diseases, the evaluation and detection of risk factors are very important for judging whether there is a disease and prognosis, and the evaluation of risk factors is also the basis for treatment decision. These risk factors include age, sex, family history, family history of early-onset thrombotic diseases, blood pressure, blood lipid, blood glucose and its control, smoking history and so on. In high-risk groups, relevant risk factors should be found early through health examination and effective intervention should be carried out as soon as possible. Prevention and treatment of thromboembolic diseases The treatment methods of thromboembolic diseases include drugs, interventional therapy and surgery. Clinicians should master three methods in an all-round way, combining prevention with treatment, so that patients can get the maximum benefit. . 1, prevention and treatment of arterial thrombosis In fact, stroke, myocardial infarction and peripheral vascular occlusion are the same kind of diseases, with similar prevention and treatment strategies and means. Therefore, we should integrate and reorganize medical resources, actively advocate the establishment of vascular disease prevention and treatment centers, so that patients can get the best prevention, diagnosis, treatment and rehabilitation, so that doctors, equipment and drugs can give full play, improve efficiency and improve the level of prevention and treatment. By preventing and treating risk factors such as hypertension, dyslipidemia and diabetes, and controlling these risk factors through lifestyle changes and drug intervention, the occurrence and development of atherosclerotic lesions can be delayed or avoided. Even if there are lesions, we can avoid plaque rupture through behavior and drug intervention, form thrombus on the basis of antithrombotic therapy, and prevent vascular events. For patients with vascular events, active intervention is needed to prevent similar vascular events from happening again. Low-dose aspirin and statins can be taken for life, which can stabilize plaque and prevent vascular events from happening again. For atherosclerotic lesions that lead to hemodynamic changes and organ hypoperfusion symptoms, appropriate interventional therapy or surgery should be chosen to restore the recanalization of the official cavity and prevent vascular events. 2. The prevention and treatment of venous thrombosis in venous thromboembolism should focus on avoiding factors that lead to slow blood flow, such as patients leaving bed as soon as possible, paying attention to regular activities of lower limbs during long-term flight travel, and using antithrombotic drugs after major surgery or serious trauma. For hospitalized patients, risk assessment should be carried out routinely, and preventive treatment should be carried out according to the risk stratification. Preventive measures for venous thromboembolism include drugs and instruments. The main drugs are low molecular weight heparin, unfractionated heparin and warfarin, and the instruments and methods are intermittent inflatable pump (IPC) and gradient pressure elastic socks (GCS), which can be used in combination. For specific indications and usage, please refer to the antithrombotic guidelines of American College of Chest Physicians (ACCP) in 2004. The purpose of DVT treatment is to prevent thrombus extension and pulmonary embolism, prevent thrombus recurrence and prevent post-thrombotic syndrome, and anticoagulant therapy is the main line. Thrombolytic therapy should be limited to those patients with huge iliofemoral deep vein thrombosis who are at risk of limb gangrene secondary to venous occlusion. The vena cava filter is suitable for thrombosis of the proximal vein of lower limbs, and anticoagulation treatment is contraindicated or has complications; Repeated pulmonary embolism after adequate anticoagulation; Patients undergoing pulmonary thromboectomy or pulmonary thromboendarterectomy. Surgery and interventional therapy are limited to possible venous gangrene to save limbs. Prevent pulmonary embolism and deep vein thrombosis. The main purpose of pulmonary embolism treatment is to quickly reduce pulmonary artery pressure and pulmonary vascular resistance and save dying patients. Thrombolytic therapy for pulmonary embolism is limited to patients with hemodynamic instability, and thrombolytic therapy should be started as soon as possible, and in large doses. Anticoagulation is the basic treatment for venous thromboembolism. Use low molecular weight heparin and warfarin at the same time. When the international standardized ratio reaches (INR)2.0-3.0, stop using low molecular weight heparin for two consecutive days and continue to use warfarin. In addition to active treatment, we must follow up regularly after discharge and take warfarin for a period of time under the condition of monitoring blood to prevent the recurrence of thromboembolism. 3. Prevention and treatment of arterial embolism For arterial embolism that has occurred, surgical embolectomy is the most effective treatment, and thrombolytic therapy and interventional therapy are not necessarily effective. The main cause of arterial embolism is atrial fibrillation. The most important way to prevent arterial embolism in patients with atrial fibrillation is to take warfarin orally. Standardized anticoagulant therapy can reduce the risk of stroke by 68% and death by 23%. Aspirin is also effective, but the effect is obviously not as good as warfarin. Warfarin and heparin (including low molecular weight heparin) are anticoagulant drugs, and their function is to prevent the formation of new thrombus. For the existing thrombus, the two drugs have no direct dissolving effect, but the body itself has a strong ability to dissolve and clear its own thrombus. The more fresh or newly formed thrombus is, the easier it is to fall off and cause embolism. Inhibition of new thrombus will prevent the possibility of pulmonary embolism or cerebral embolism in patients with deep vein thrombosis or atrial fibrillation. Summary Thrombosis prevention and treatment is a systematic project, where there are blood vessels, thrombotic diseases may occur, involving all systems of the whole body, which requires the cooperation of various professional doctors. The treatment of thromboembolic diseases includes drugs, intervention and surgery. Doctors engaged in the treatment of thromboembolic diseases should be proficient in everything and choose the most beneficial treatment for patients. Only in this way can the elderly be healthier and live longer.