Why do some patients need valve replacement? If the normal heart valves are invaded by rheumatic fever or bacteria, resulting in deformation, thickening, adhesions, calcification, or due to trauma or congenital malformation, a group or two groups of valves become narrowed or incomplete, and lose their one-way valve function, and the valve lesion cannot be effectively treated by closed dilatation or shaping, then the original diseased valve must be surgically removed under extracorporeal circulation and replaced with an artificial valve to restore the one-way valve physiological function and relieve or alleviate symptoms. In this case, the original diseased valve must be surgically removed under extracorporeal circulation and replaced with an artificial heart valve to restore the physiological function of the one-way valve and to relieve or alleviate the symptoms. Thousands of patients around the world have been rehabilitated by this procedure every year. It has been more than 30 years since the first valve replacement surgery in China. The clinical results are positive. Hong Hao, Department of Cardiac Surgery, Wuhan Union Hospital (d) How many types of artificial valves are there? Which kind of valve is good for replacement? Artificial heart valves are divided into two main categories. One is the mechanical valve, and the other is the biological valve. The former is made of advanced synthetic materials, while the latter is made of both synthetic advanced materials and complex chemically treated biological tissue membrane surface. Each has its own characteristics and advantages and disadvantages. The advantage of a mechanical flap is its durability, while the disadvantage is that it requires lifelong anticoagulation and has a higher rate of thromboembolism. As for the type of flap you are suitable for, your doctor will make a choice based on your requirements and condition.