Complete medial canal fibrosis.
Our otologic examination revealed that the right ear canal was short and terminated with a skin-covered barrier (figure 1). Audiometry and tympanometry of the right ear revealed a flat 30-dB conductive hearing loss. A diagnosis of complete acquired medial canal fibrosis was made and subsequently confirmed by temporal bone computed tomography (CT) (figure 2).
[FIGURES 1-2 OMITTED]
Acquired medial canal fibrosis is a rare atresia that is characterized by the formation of thick, solid fibrous tissue in the medial part of the external ear canal. It may be associated with chronic otitis media or chronic otitis externa, and it may occur following a tympanoplasty. Other causes include nonsurgical trauma such as thermal or chemical burns and gunshot wounds. It has been speculated that the initial insult stimulates the formation of granulation tissue on the epithelium of the external ear canal and on the tympanic membrane. With recurrent infection, granulation tissue matures with extensive fibrosis, and the external ear canal may become partially or completely obliterated by this inflammatory process. (1)
The only effective treatment is surgery. The main goals of surgery are to reestablish a patent epithelium-lined ear canal for good sound conduction and to prevent canal cholesteatoma. The surgical procedure involves removal of the fibrotic tissue, canaloplasty, meatoplasty, and skin grafting. (1-4)
In the case described herein, a canaloplasty with skin grafting and tympanoplasty resulted in closure of the airbone gap and resolution of symptoms. At the 6-month follow-up, the patient remained symptom-free.
(1.) el-Sayed Y. Acquired medial canal fibrosis. J Laryngol Otol 1998: 112:145-9.
(2.) Slattery WH III, Saadat R Postinflammatory medial canal fibrosis. Am J Otol 1997:18:294-7.
(3.) Birman CS, Fagan PA. Medial canal stenosis--Chronic stenosing external otitis. Am J Otol 1996;17:2-6.
(4.) Eshraghi AA, Ulubil SA. Partial medial canal fibrosis. Ear Nose Throat J [In press].
From the University of Miami Ear Institute, Department of Otolaryngology, University of Miami Miller School of Medicine.
S. Arif Ulubil, MD; Adrien A. Eshraghi, MD
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|Title Annotation:||OTOSCOPIC CLINIC|
|Author:||Eshraghi, Adrien A.|
|Publication:||Ear, Nose and Throat Journal|
|Date:||Jan 1, 2006|
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