Abstract
Congenital labyrinthine cholesteatoma can cause varying degrees of hearing loss and vertigo. Hearing preservation is not always possible when treatment involves total labyrinthectomy. Since 1969, there have been several case reports and case series documenting hearing preservation following surgical treatment of congenital labyrinthine cholesteatoma. However, none of the case reports or case series documents the patients’ vestibular complaints after surgery. Herein, we report a case series of four patients who were treated with the goal of hearing preservation and resolution of vertigo after partial or complete removal of the bony labyrinth for congenital inner ear cholesteatoma. We will also discuss possible explanations for the mechanisms of preservation of hearing and vestibular function with a review of the current literature.
1
Introduction
Congenital inner ear cholesteatoma is usually associated with varying degrees of sensorineural hearing loss as well as disruption of vestibular function. Current treatment for congenital inner ear cholesteatoma involves removal of the cholesteatoma and possible resection of the bony labyrinth resulting in difficulty in preserving hearing and vestibular function. The general belief is that destruction of any portion of the membranous labyrinth invariably leads to sensorineural hearing loss. There are a number of case reports and small series reporting hearing preservation after resection of part or all of labyrinth, however none clearly documents the post-operative status of the patient’s vestibular complaints.
In this review, we report a case series of four patients with varying degrees of hearing preservation and vertigo resolution after resection of the bony labyrinth for congenital inner ear cholesteatoma and discuss the pathophysiological aspects of hearing preservation in this unusual condition.
3
Report of cases
3.1
Case 1
The patient is a 51-year-old man who presents with complaints of periodic dizziness and progressive right-sided hearing loss. Initial examination showed normal facial function and normal otoscopic examination. Bedside vestibular testing was normal with the exception of a tendency to veer to the right while performing the stepping test. The preoperative audiogram showed normal sloping to mild sensorineural hearing loss in the left ear with a moderate to profound mixed loss in the right ear ( Fig. 1 A ). Preoperative computed tomography (CT) of the temporal bone revealed what appeared to be an expansile soft tissue mass with erosion of the otic capsule consistent with labyrinthine congenital cholesteatoma based in the region of the internal auditory canal, vestibule, and labyrinth ( Fig. 1 B). The patient underwent preoperative videonystagmography (VNG) testing that demonstrated near-complete ablation of the vestibular function on the right side with reduced vestibular response (RVR) of 83% in the right ear. After discussing the risks, benefits, and alternatives, surgery was offered. The patient was taken to the operating room and a postauricular translabyrinthine approach to the internal auditory canal was completed. Extradural removal of cholesteatoma from the internal auditory canal and posterior fossa dura was performed. The cholesteatoma had invaded into the vestibule and the horizontal semicircular canal was significantly eroded. A labyrinthectomy was then performed with care taken to open the vestibule. There was also cholesteatoma noted on the internal auditory canal and along the facial nerve, which was also removed. A very small portion of the cholesteatoma was unable to be removed from the geniculate ganglion and will be followed. A small CSF leak was noted coming from the internal auditory canal, which was covered with temporalis fascia followed by fibrin glue. Fibrin glue was also layered up to the mastoid cortex and then covered with Gelfoam before closing the periosteum.
Postoperatively the patient was admitted to the floor on intravenous ampicillin/sulbactam (Unasyn) therapy with three doses of intravenous dexamethazone (Decadron). His facial nerve function was noted to be intact after surgery and he did not experience dizziness. The Weber test lateralized to the affected ear. Patient was discharged on postoperative day one with ten days of oral antibiotics. In the immediate post-operative period, the patient reported good hearing subjectively when examined at bedside. However, at his 3-month follow up, the audiogram showed worsened right-sided hearing now with severe to profound sensorineural hearing loss ( Fig. 1 C). He continues to be free of vertiginous dizziness.
3.2
Case 2
Patient is a 29 year-old man with the chief complaint of pressure-induced dizziness. He has a history of left tympanomastoidectomy performed at an outside institution for chronic otitis media and a large congenital cholesteatoma. After a period of time, the patient presented with new onset vertigo. It was noted on examination that the Hennerbert’s sign was positive. Office examination showed a narrow right ear canal with a large recurring cholesteatoma eroding the attic and extending towards the antrum. His audiogram showed bilateral mild to moderate mixed hearing loss with good word recognition score (92% on the right and 100% on the left) ( Fig. 2 A ). CT of temporal bone showed a cholesteatoma-like lesion involving the right middle ear and the vestibule of the labyrinth ( Fig. 2 B). The cholesteatoma resulted in erosion of the tegmen tympani with involvement of the facial canal. A modified canal wall down procedure was performed and a small cuff of matrix was left on the vestibular epithelium in order to preserve hearing. Intraoperatively, invasion of the fallopian canal was confirmed. The cholesteatoma was peeled off the epineurium of the facial nerve preserving its integrity.
Post-operatively, the patient retained his hearing with normal facial function. However, the patient subsequently developed recurrent cholesteatoma in the region of the horizontal semicircular canal with extension to the ampulla of the superior semicircular canal. He was then taken back to surgery and the residual cholesteatoma at the level of the ampulla of the superior, horizontal and part of the posterior semicircular canals was exteriorized and marsupialized. The patient’s vertigo has resolved post-operatively.
Patient audiogram post-operatively showed bilateral mixed mild to moderate hearing loss ( Fig. 2 C). Periodically, patient experiences facial nerve dysfunction from the cholesteatoma, which resolves with office-based cleaning using the otomicroscope.
3.3
Case 3
Patient is a 17 year-old male who was referred in 2009 to our tertiary medical center for evaluation of imbalance and dizziness. The patient’s audiogram showed left-sided moderate conductive loss with an air–bone gap of 50 dB ( Fig. 3 A ). The CT scan showed extensive cholesteatoma with erosion of the superior and horizontal semicircular canals. In addition, erosion of the tegmen was present. One month prior to his clinic visit, he developed left-sided otorrhea with subsequent acute onset facial paralysis, which resolved with antibiotics and steroid usage. On the initial physical examination, fistula test was positive. Torsional nystagmus was present confirming the involvement of the superior semicircular canal along with the horizontal one. The patient underwent surgical resection and exteriorization of the cholesteatoma. Some cholesteatoma matrix was left over the superior and horizontal semicircular canals in effort to avoid violating the endosteum and subsequent hearing loss. Patient was then lost to follow up until presenting back with severe vertigo. Repeat CT scan showed recurrence of the cholesteatoma with involvement of the facial nerve and the horizontal semicircular canal ( Fig. 3 C). He was taken back to surgery and the cholesteatoma was removed except in the area on the horizontal and geniculate ganglion of facial nerve. Matrix was also left on the ampulla of the superior semicircular canal and horizontal semicircular canal. An ossiculoplasty was also performed at the time because of incus fixation.
