There are two types of prosthetic valves, mechanical and biological. (1) Advantages of mechanical valves: mechanical valves are designed to last longer than biological valves, and a single valve replacement can basically last a lifetime. Disadvantages: A. Mechanical valves installed into the body, will grow thrombus, in order to prevent thrombosis, you need to take anticoagulants (warfarin) for life. At the same time, in order to adjust the dose of warfarin, it is necessary to regularly visit the hospital to take blood tests to monitor the anticoagulation index. This may affect the patient’s quality of life after surgery. b. Overdose of warfarin can lead to bleeding, and underdose of warfarin can lead to thrombosis. c. In a quiet environment Sometimes you may hear a “tick-tock” sound in the chest, which is normal for mechanical valves, but if you are very sensitive to noise and have insomnia, you should consider this when choosing a valve. Of course, the vast majority of patients can accept and adapt to this sound.D. Taking warfarin during pregnancy may lead to fetal malformations, and during pregnancy and delivery may lead to fetal, placental, and maternal hemorrhage, thus endangering the lives of mother and child, so women of childbearing age who are ready to replace their valves should consider this carefully, while men do not have this problem, which will be described in detail later. (2) The advantages of a biologic valve, in contrast to a mechanical valve, are that it does not require a lifetime of anticoagulant medication, but only 3-6 months, during which time only, periodic blood tests are required, and if there is no atrial fibrillation, warfarin anticoagulation can be discontinued after 3-6 months, so the risk of thrombosis and bleeding associated with it is greatly reduced. The disadvantages are: poorer durability than mechanical valves, shorter service life than mechanical valves, and damage to the bioprosthetic valve over time. Therefore, if the bioprosthetic valve becomes damaged after several years of surgery, a second valve replacement surgery will be faced. In general, the younger the patient is, the faster the bioprosthetic valve will break down, the shorter the service life, and the greater the chance of a second surgery. How long does it last for each patient? It is impossible to give a definitive answer to this question because the life expectancy varies depending on the patient’s physical condition, metabolic status, exercise level, basal heart rate, blood pressure, etc. Therefore, when choosing a valve, you need to fully anticipate the possibility of a second surgery. The choice between mechanical and biologic valves has its own advantages and disadvantages and is based on the patient’s age, general condition, co-morbidities, as well as his or her own life, work, physical strength, psychological factors, economic conditions, and other practical considerations to see which one is suitable for him or her. In summary: In general, biological flaps are suitable for the following situations: (1) Women of childbearing age who wish to become pregnant. This is because there is a risk of fetal malformations, bleeding and other problems for patients who are taking warfarin before and during pregnancy with a mechanical flap exchange. This problem can be avoided if the biological flap is replaced. (2) In terms of age, a bioprosthetic valve can be preferred for mitral valve replacement over 65 years of age and aortic valve replacement over 60 years of age. (3), Suffering from bleeding disorders or being a bleeding body themselves, they cannot take anticoagulants for a long time. (4), in distant mountain villages where long-term anticoagulation monitoring cannot be performed. (5) Those who do not want to use mechanical flaps, do not want to make frequent trips to the hospital for blood tests (even if it is once a month), and require a higher quality of life. (6) Patients with a relatively poor general condition and physical fitness (not expected to live long).