There are advantages and disadvantages with either choice. A mechanical valve lasts longer than a tissue valve, but you'll have to be on blood-thinning medication for the rest of your life to reduce the risk of blood clots. The main advantage of a tissue valve is that it does not typically require life-long blood-thinning medication. Depending on your specific requirement the cardiac surgeon will suggest what’s best for you. The key is to choose the valve that best fits your lifestyle and your goals.