Viability properties in autologous fascia lata heart valve grafts: a transmission electron microscopical study.

Four frame-mounted autologous fascia lata heart valve grafts in situ for 18 to 41 months as well as one free-mounted fascia cusp in situ for 10 years were examined by transmission electron microscopy (TEM). In all cusps, areas of well-preserved subcellular structures were found as well as areas with degeneration and fragmentation of both nuclear and collagen fibers. Fibrocytes, fibroblasts, and a special cell form, the myofibroblast, were encountered. The appearance of this last cell form may explain the shrinkage phenomenon encountered in these valves, all retrieved at reoperation because of valve dysfunction. Some of the fascial cells thus stayed alive within the bloodstream for up to 10 years.