Abstract
In tympanoplasty, the formation of a so-called retraction pocket is still a serious problem. In order to prevent the retraction pocket, it is desirable to preserve the posterior wall of the external auditory meatus at surgery. However, it often becomes necessary to remove the posterior wall with the bony bridge for performing radical excision of the lesion. In this procedure, it should be necessary to reconstruct the posterior wall using a material which is compatible with human tissues. An investigation was performed on the hydroxylapatite ceramic implant as a reconstruction material for the posterior bony wall. Subjects were 36 ears of otitis media with cholesteatoma and 16 ears without cholesteatoma, and a follow-up study was made for periods of 6 to 37.8 months after operation.
The results showed that the retraction pocket was formed in four cases and the cholesteatoma recurred in only two cases. In 13 cases, the apatite plate was exposed due to a failure of covering by fascia, but it was finally covered with extending epithelium in 5 cases without any serious problem, and the other cases tended to be covered by the soft tissue. The incidence of the retraction pocket formation was much lower in cases with hydroxylapatite than in cases using other reconstructive materials, and there was no case in which the apatite was rejected. These indicate that the apatite ceramic is quite stable within the living tissues, and has a high biocompatibility. Thus, it is concluded that the hydroxylapatite plate is an excellent artificial material for the reconstruction of bony canal.
