Endoscopy in otology and neurotology.

Since the early 1980s rigid endoscopes have been used by otorhinolaryngologists in the United States primarily for sinus surgery. Recently rigid endoscopes have been used as an adjunct to standard otologic and neurotologic procedures. Diagnostic inspection of the middle ear can be performed through a myringotomy incision to rule out perilymphatic fistula, for identification of cholesteatoma, or for evaluation of the status of the ossicular chain. During chronic ear surgery endoscopes can be used to locate hidden cholesteatoma in difficult to visualize areas such as the eustachian tube, attic, sinus tympani, and beneath an intact posterior canal wall. In acoustic neuroma surgery in which hearing preservation is an objective endoscopes are used to inspect the lateral aspect of the internal auditory canal (IAC) for residual tumor. During vestibular neurectomy endoscopes are used to view the IAC and to help identify the cochleovestibular cleavage plane. The applications, techniques, and limitations of rigid endoscopy in otology and neurotology are discussed.