Herniation of the facial nerve in the middle ear

Surgery of the ear and the lateral skull base: pitfalls and complications

Surgery of the ear and the lateral skull base is a fascinating, yet challenging field in otorhinolaryngology. A thorough knowledge of the associated complications and pitfalls is indispensable for the surgeon, not only to provide the best possible care to his patients, but also to further improve his surgical skills. Following a summary about general aspects in pre-, intra-and postoperative care of patients with disorders of the ear/lateral skull base, this article covers the most common pitfalls and complications in stapes surgery, cochlear implantation and surgery of vestibular schwannomas and jugulotympanal paragangliomas. Based on these exemplary procedures, basic "dos and don'ts" of skull base surgery are explained, which the reader can easily transfer to other disorders. Special emphasis is laid on functional aspects, such as hearing, balance and facial nerve function. Furthermore, the topics of infection, bleeding, skull base defects, quality of life and indication for revision surgery are discussed. An open communication about complications and pitfalls in ear/lateral skull base surgery among surgeons is a prerequisite for the further advancement of this fascinating field in ENT surgery. This article is meant to be a contribution to this process.

Delayed facial palsy after stapedectomy

OBJECTIVE

To study the incidence, pathogenesis, and prevention of delayed facial palsy after stapedectomy.

STUDY DESIGN

Retrospective case review.

SETTING

Otology/neurotology referral center.

PATIENTS

A series of 2152 stapedectomy procedures in 2106 patients over 12 years.

INTERVENTION

Delayed facial palsy after stapedectomy was studied.

MAIN OUTCOME MEASURE

House-Brackmann facial nerve grading system and serum antibody titer tests for herpes simplex virus type I and type II, and varicella zoster virus.

RESULTS

Delayed facial palsy occurred in 11 of 2152 procedures. Delayed facial palsy occurred from 5 to 16 days (mean 8) after stapedectomy. Predisposing factors were bony facial canal dehiscence with bare or bulging facial nerve herniation in 5 patients; chorda tympani nerve stretched, manipulated, or cut in 2 patients; granulomatous reaction to Gelfoam in 1 patient; fever blisters on the upper lip in 1 patient; and sinusitis in 2 patients. Elevated anti-varicella antibody titers were found in all 6 patients studied. Anti-herpes simplex type I and II antibody titers were elevated in 5 of 6 patients. Acyclovir was effective in preventing delayed facial palsy in 1 patient who had undergone revision stapedectomy and experienced delayed facial palsy after previous stapedectomy in the same ear with elevated anti-herpes antibody titer.

CONCLUSIONS

Delayed facial palsy occurred in 0.51% of patients after stapedectomy. Serologic investigation suggests activation of latent herpesvirus. Mechanical irritation of the facial or chorda nerve during operation may trigger the activation. The anti-herpesvirus agent acyclovir may prevent delayed facial palsy after stapedectomy in patients suspected of having this complication.

Facial canal dehiscence: a report of 1,465 stapes operations

We retrospectively reviewed 1,465 stapes operations for facial canal dehiscences. The incidence of facial canal dehiscence was found to be 11.4%. A facial canal dehiscence with protrusion of the facial nerve is more common than a dehiscence without protrusion. In addition, 3 cases (0.2%) had a herniation of the facial nerve. Our data suggests that heredity could be one of the factors associated with a facial canal dehiscence. If an operated ear shows a dehiscent facial canal, there is a 29% possibility that the contralateral ear also has a dehiscence. Bilaterality of facial canal dehiscence is, therefore, exceptional.

Four variations of the Mondini inner ear malformations as seen in microdissections

Four variations and degrees of severity of the Mondini malformation were found in the temporal bones from two neonates, one with congenital heart disease and the other with trisomy D, and from one teenager with leukemia: 1) short cochlea and normal vestibular organs; 2) short cochlea and persistent horizontal canal anlage; 3) markedly shortened cochlea with no modiolus, wide internal auditory meatus, and persistent horizontal canal anlage; 4) same as variation 3, but with persistent anlagen in all semicircular canals. Variations 3 and 4 were from the case of trisomy D, in which the left cochlea had a normal hair cell population but few nerve fibers, and the intraganglionic spiral bundle was displaced from Rosenthal's canal to the osseous spiral lamina. The right ear had no cochlear nerve fibers; the organ of Corti was present, but hair cells were unusually small. In the case of trisomy D, both ears showed subtotal loss of vestibular nerve fibers. Although the rudimentary cristae of the right ear had numerous hair cells, the macular hair cells were fewer and malformed. No hydrops was present.