Tissue heart valves are usually made from animal tissue (heterograft) which is affixed to metal or polymeric supports. Bovine tissue is commonly used, but some alternatives are made from pig tissue. Tissue replacements are used to prevent rejection and calcification.
An allogeneic aortic valve graft (or allograft) is an aortic valve from a human donor, taken either postmortem, or from the heart after the donor has undergone a heart transplant.[7]
Pulmonary autograft (or what is known as the Ross method) during which the aortic valve is replaced with the pulmonary valve (valve between the right ventricle and the pulmonary artery) of the same patient, and a pulmonary valve allograft (graft taken from a cadaver) is taken to replace the removed valve. This procedure was carried out for the first time in It was established in 1967 and is mainly used in children, because it allows the patient’s pulmonary valve (which was replaced by the aortic valve) to grow as the child grows.
Tissue valves may remain functional (functional) in the heart for 10 to 20 years, but they tend to degenerate more often in younger patients, and research is ongoing to find new ways to preserve tissue for a longer period.[8]
