This is an issue that is often discussed and frequently consulted by patients. In principle, mechanical valves are recommended for younger patients under 60 years of age, while biological valves are generally preferred for those over 60 years of age, and mechanical valves require a lifetime of anticoagulants after replacement. After all, it is metal, and after it is put into the human body, despite the improved material and strong resistance to wear and tear. However, it is easy to form blood clots, so it is necessary to take anticoagulants every day to prevent the formation of blood clots, and the resistance to blood flow is greater. The advantage of the mechanical flap is that it can be used for a long time, in principle, for 40 to 50 years, which is its biggest advantage. The disadvantage is that you have to take anticoagulants for life, and if you take anticoagulants and have to have frequent blood tests, it is not appropriate to eat more or less without blood tests. In remote mountainous areas where blood tests are required, it is easy to have an accident if you eat more or less, and it may not always be appropriate for patients in remote mountainous areas. The biggest advantage of the biological valve is that it is generally not necessary to take anticoagulants for six months after surgery, but the life expectancy and design life is not as long as that of the mechanical valve, which used to be ten years. But not necessarily, this is expected, there may be some patients 30 to 40 years also did not break, may also be some patients mechanical flap said to be 40 to 50 years, may be a few years bad, because after all is artificial. Another thing is that it is not as strong as the mechanical valve. After replacing the mechanical valve, such as the aortic valve and mitral valve, should we not replace them again in the future? Generally, for these two valves, they do not need to be replaced, but it depends on the individual case. If the valve is a biological valve, it may need to be replaced in 20 years. Even if the valve is mechanical, it is possible that the valve parts may break down and be replaced due to various reasons, such as trauma or special circumstances. Everyone has special circumstances, for example, if you are already 60 or 70 years old, it is recommended that you use a biological valve. If you are younger, it is better to go with a mechanical flap. Advantages and disadvantages of biologic valves Biologic valves made from biologic materials are classified as bovine pericardial sewn valves and porcine aortic valves, homograft valves, which are made after processing. These valves are chemically treated during the manufacturing process to make them free of xenogeneic antigenicity and to make them pliable and durable. Nonetheless, biologic valves do not last as long as autologous valves, so that after about 10 years of use, the valves gradually develop degenerative disease and often require a second surgery, which is the greatest disadvantage of biologic valves. However, the advantage of biologic valves is that they are very similar in shape and blood flow pattern to human valves and do not require any long-term medications, especially anticoagulants, thus there is no risk of drug-induced complications. The incidence of valve-related complications such as thrombosis and thromboembolism is also lower than that of mechanical valves.