Abstract
In reviewing a history of surgery for middle ear inflammation from the primitive simple mastoidectomy to the latest tympanoplasty, opening and eradication of the mastoid air cell systems are essentially performed. In radical mastoidectomy, the mastoidectomy cavity was widely opened to the external auditory meatus, and this procedure results in destroying the air cell systems and forming abnormal anatomical structure. Several surgical techniques were proposed to manage the mastoidectomy cavity. Mastoidectomy preserving posterior wall of external auditory meatus, so called “closed method” oftympamoplasty, was one of the technique to dissolve the problem. In this method, the mastoidectomy cavity opened to the tympanic cavity instead of external auditory meatus. Increased aeration volume of the middle ear cavity was supplied only through the Eustachian tude, and its dysfunction induced tympanic membrane retraction and cholesteatoma formation.
Importance and necessity of the air cell systems were observed by clinical examinations and experiments using piglet, whose middle ear has air cell systems resembling to human middle ear, and our results showed that the mucosa of air cell systems performed active gas-exchange and maintained middle ear pressure.
According to these results, an importance of preserving gas-exchange capacity of the air cell systems in the mastoid surgery was described.
