A mechanical valve is made of metal and is carefully designed to mimic the native heart valve. It has a ring, like your own natural heart valve, to support the leaflets. Like your own heart valve, the mechanical valve opens and closes with each heartbeat, permitting proper blood flow through the heart. To prevent any blood clots from developing on the valve, which can cause complications, a mechanical valve replacement requires you to take blood thinners (anticoagulation medicine) daily.
The tissue valve is a native valve taken from an animal or hand-made from animal tissue. The tissue is chemically treated and prepared for human use in order to prevent rejection. Some tissue valves have a frame, or stent, that supports the valve, and some valves are stentless (no framework). A very thin polyester mesh cuff is sewn around the outside of the valve for easier implantation. Long-term blood thinners are not necessary after implantation of a tissue valve.