[Morphologic studies of autologous and homologous ossicles after long-term implantation].

BACKGROUND

Although ossicular bone implants have been used to restore the middle ear sound conduction mechanism for more than 30 years, controversy still exists regarding their morphology after long-term implantation.

METHODS

Fifty-seven ossicular implants that had been in the middle ear for a mean duration of 12 years (ranged from 3-33 years) were removed at 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, extended bone resorption, and inflammatory cells. The findings were correlated to origin, duration of implantation, and the reason for revision surgery.

RESULTS

More than a half of the specimens with cholesteatoma and chronic otitis media as reasons for revision surgery showed extended bone resorption and inflammatory cells. Even in clinically uninfected ears, inflammation and bone resorption could be observed. Lymphocytic infiltration as an inflammatory pathologic change predominates in autologous implants.

CONCLUSIONS

On the basis of these histological observations, we conclude that autologous ossicles from cholesteatoma should not be used in reconstructive middle ear surgery. Furthermore, the use of ossicular implants after revision surgery should be avoided.