[Destruction of the aortic allo- and xenovalves of the heart depending on their position and time of transplantation].

The aortic valve, as well as the other valves of the heart, has a cellular structure. Collagenous fibres form the skeleton of the cellular structures, and the plexus of thinner fibres--the "walls". At early periods following the implantation destruction of thin fibres distributed along the periphery of the alveolus takes place. In the course of prolonged functioning of the allo- and xenovalves in a mitral position the large collagenous fibres collapse, defibration thereof develops and slits-vacuums and "cysts" are formed. In the valves which functioned for a long time in the tricuspid position no considerable destructive changes in the connective-tissue carcass take place.