MORPHOLOGY OF AUTOLOGOUS AND HOMOLOGOUS O SSICULAR IMPLANTS AFTER LONG-TERM IMPLANTATION

Although ossicular bone implants have been used to restore the middle ear sound conduction mechanism for more than 30 years, controversy sti ll exists regarding their morphology after long-term implantation. Met hods: Fifty-seven ossicular implants that had been in the middle ear f or a mean duration of 12 years (ranged from 3-33 years) were removed a t the time of revision surgery and prepared for histological study by light microscopy. These revision operations were performed because of failure to control the disease and/or persistent or recurring hearing loss. Each ossicle was examined for the presence of living bone, exten ded bone resorption, and inflammatory cells. The findings were correla ted to origin, duration of implantation, and the reason for revision s urgery. Results: More than a half of the specimens with cholesteatoma and chronic otitis media as reasons for revision surgery showed extend ed bone resorption and inflammatory cells. Even in clinically uninfect ed ears, inflammation and bone resorption could be observed. Lymphocyt ic infiltration as an inflammatory pathologic change predominates in a utologous implants. Conclusions: On the basis of these histological ob servations, we conclude that autologous ossicles from cholesteatoma sh ould not be used in reconstructive middle ear surgery. Furthermore, th e use of ossicular implants after revision surgery should be avoided.