[Direct observation of the tympanic cavity by superfine fiberscopy through the eustachian tube].

It was impossible to observe directly the tympanic cavity with the ear drum intact. The superfine fiberscope, developed by the Department of Otolaryngology, Tokyo Medical College, makes it possible to observe the tympanic cavity through the eustachian tube without any surgical intervention such as myringotomy. This fiberscope is flexible and very fine, having an outer diameter of 0.6-0.8mm. Using this new fiberscope, the following structures can be observed: the handle of the malleus, the long process of the incus, the incudostapedial joint, the head of the stapes, the crus of the stapes, the tendon of the tensor tympani muscle and the promontory. Observation results are presented for 138 ears with various disorders: cholesteatoma, tympanosclerosis, congenital malformation, ossicular dislocation, otosclerosis, otitis media with effusion, chronic otitis media, etc. All patients could be tested with local anesthesia in the outpatient clinic except very young children. The findings were easily recorded on either photographs or video tapes. This superfine fiberscope was of great value in the diagnosis of pathologies affecting middle ear structures in outpatient clinics, since no surgical intervention was necessary in the procedure. In addition, it was very useful for making highly detailed studies and for discussion after the examination.