Endaural labyrinthectomy.

[FIGURE 1 OMITTED]

Labyrinthectomy is a last resort procedure to treat severe vertigo, usually in patients with Meniere disease who have failed all conservative medical and surgical means of treatment, especially when the disease is predominantly unilateral. Labyrinthectomy can be defined as a procedure to destroy and/or eliminate the contents of the inner ear, namely the membranous labyrinth.

There are two types of labyrinthectomy: physical and chemical. Physical labyrinthectomy is a surgical procedure in which the surgeon removes the inner ear contents, especially the utricle and attached ampullae. Chemical labyrinthectomy refers to the elimination of the vestibular end organs, especially the utricle and semicircular canals, via transcanal instillation of an ototoxic drug such as streptomycin or gentamicin.

Postauricular labyrinthectomy has been used for hundreds of years, whereas chemical labyrinthectomy was not described until the 1940s. In the 1950s, first Cawthorne and then Schuknecht popularized the transcanal ototoxicity approach, and it has recently received broader attention and utilization.

For 30 to 40 years, we have successfully used an endaural approach to labyrinthectomy that combines the desirable elements of both physical and chemical labyrinthectomy, which renders a mastoidectomy unnecessary. With this approach, the surgeon can achieve good exposure and use both hands (figure 1). The endaural labyrinthectomy can involve a small or large incision and exposure, depending on the anatomy of the external auditory canal. A large tympanomeatal flap is elevated, and if the posterior bony canal is obstructed, it can be enlarged with a drill. An atticotomy is performed for wider exposure; if need be, an atticoantrotomy can be enlarged for a better view of the horizontal semicircular canal (figure 2). The incus is removed, and then the promontory is removed with a small drill for good exposure. The contents of the inner ear are removed, including the otolithic organs, especially the utricle with its attached ampullae beneath the horizontal fallopian canal. Care is taken not to traumatize the spherical recess of the saccule straight through the oval window because any small break in this area results in cerebrospinal fluid (CSF) flow; if a CSF leak does occur, it should be packed off. After the membranous labyrinth is removed, Gelfoam saturated with streptomycin or gentamicin is placed in the inner and middle ears, and the endaural tympanomeatal flap is replaced and closed.

[FIGURE 2 OMITTED]

Endaural surgical exposures have many applications in otology and neurotology. Endolymphatic labyrinthectomy enhances exposure and bimanual dexterity. It provides excellent results that are comparable to those seen with postauricular transmastoid labyrinthectomy in patients with intractable vertigo associated with other vestibular symptoms.

Suggested reading

Paparella MM. Otology. In: Saunders WH, Paparella MM, Miglets AW. Atlas of Ear Surgery. 3rd ed. Vol. 2. St. Louis: Mosby; 1980.

Michael M. Paparella, MD

From the Department of Otolaryngology, University of Minnesota, and the Paparella Ear Head and Neck Institute, Minneapolis