Prosthetic valves are divided into two categories: mechanical valves and biological valves. Among them, biological valves are artificial heart valves made by applying materials from other animal bodies and processing them. The two most commonly used biomaterials are bovine pericardial valves and porcine aortic valves, and there is basically no difference in the service life of the two valves. Biologic valves can be structurally divided into stented and unstented biologic valves. A stented bioprosthesis is a porcine aortic valve or a bovine pericardial piece sewn and fixed to an artificial stent to maintain the shape of the heart valve; a stentless bioprosthesis is a porcine aortic valve and the ascending aorta attached to it taken off and treated together, thus forming a valve with a segment of the ductal structure attached. The most clinically used stented bioprosthetic valve is currently used because of its ease of implantation and stable performance. Biologic valves do not require lifelong anticoagulation but have a limited lifespan. Advantages: About 3-6 months after implantation, the leaflet surface is covered with deposited fibrin and endothelial tissue, and the leaflet material is no longer in contact with the patient’s blood, avoiding the coagulation reaction that activates the blood and therefore eliminating the need for anticoagulation therapy, which is the greatest advantage of biologic valves. Disadvantages: Because biomaterials have their own lifespan, it is generally believed that 7-10 years after surgery, the biologic flap begins to show some deterioration, although function can be maintained; 15-20 years after surgery, the flap needs to be replaced again, which is the greatest disadvantage of biologic flaps. The rate of destruction is influenced by the implantation site, patient age, heart rate, and biomaterial. Physician tips The use of biologic and mechanical valves is not absolute. The type of prosthetic valve used in valve replacement surgery will be analyzed by the surgeon on a case-by-case basis. The decision is usually based on the patient’s physical condition, age, occupation, physical strength, mental status, religious beliefs, and the patient’s opinion on valve selection.