CHAPTER VII
OPERATIONS UPON THE LABYRINTH
GENERAL CONSIDERATIONS
Labyrinthine suppuration usually occurs in the course of a chronic middle-ear suppuration; more rarely, as the result of tuberculous disease of the temporal bone, or in consequence of an acute middle-ear suppuration. In the latter case, however, it is a matter of experience that, although symptoms of labyrinthine suppuration may be present, they almost invariably subside as a result of drainage of the middle ear and mastoid. This is an important point which should be remembered, as otherwise the labyrinth may be explored unnecessarily at a considerable risk to the patient’s life.
The most frequent paths of extension of the pyogenic infection from the middle ear to the internal ear are through the external semicircular canal, the promontory, and the fenestra ovalis, the result of cholesteatomatous erosion, caries, or necrosis. Hinsburg, in 198 cases of labyrinthine suppuration, traced the infection in 61 cases. In 27 cases the infection had entered through the external semicircular canal, in 17 through the fenestra ovalis, in 7 through a fistula of the promontory, in 5 through the fenestra rotunda and ovalis, and in 5 through a fistula in the posterior or superior semicircular canal (Archives of Otology, 1902, vol. xxxi, p. 116).
Although operations on the labyrinth are practically limited to suppurative disease, yet under certain conditions they are justifiable when no suppuration is present.
These operations may consist in partial or complete opening of the semicircular canals, or of the vestibule, or in removal of the cochlea, or complete extirpation of the labyrinth.
INDICATIONS FOR OPERATION
(i) In non-suppurative labyrinthitis.
(a) To relieve vertigo. This operation is only justifiable if the condition cannot be cured by other methods, and is so distressing as to render the patient’s life unendurable.