[Early scanning electron microscopy changes of the surface of the leaflets of orthotopic transplanted glyceraldehyd-conditioned conus-pulmonalis xenografts. An experimental study in dogs].

The surface of the leaflets of orthotopic transplanted glutaraldehyd-conditioned conus-pulmonalis xenografts show when analysed by a scanning microscope the following constant changes. Within seconds the surface of the leaflets is covered by a grainy layer of proteins followed by fibrin threads. Cellular elements of the blood--like platelets, white blood cells, macrophages and microthrombi--are incorporated in the fibrin network. This leads, after several weeks to a fibrous layer especially over the stiff parts of the valve. No endothelium was seen even after 6 months.