<P> Tissue heart valves are usually made from animal tissue , either animal heart valve tissue or animal pericardial tissue . The tissue is treated to prevent rejection and calcification . </P>
<P> Tissue heart valves are usually made from animal tissue , either animal heart valve tissue or animal pericardial tissue . The tissue is treated to prevent rejection and calcification . </P>
during valve replacement surgery a valve that comes from an animal is known as
during valve replacement surgery a valve that comes from an animal is known as
Tissue heart valves
Tissue heart valves