External Auditory Canal Exostosis

Abstract

A 62-year-old male surfer presented with a gradual bilateral hearing loss, worse on the right side. On otoscopy, his external auditory canals were occluded by multiple bony outgrowths (figure). Audiometry revealed a right-sided conductive hearing loss with normal bone conduction thresholds. The patient underwent surgery on his right, poorer-hearing ear. Through a postauricular approach, the exostoses were removed with a high-speed drill and diamond burs.Exostoses are composed of immature layers of lamellar bone that cause a progressive stenosis of the external ear canal. They are typically bilateral, they occur at suture lines, and they are associated with repeated exposure to cold water. Recurrent external otitis can develop if water becomes trapped medial to the exostoses.Surgery is indicated in cases of recurrent infection or conductive hearing loss. Although transcanal removal has been described, the philosophy at the House Clinic is (1) to use a postauricular approach to maximize visualization, (2) to begin with an anterior dissection to avoid facial nerve injury, and (3) to use high-speed drills with diamond burs to facilitate safe, controlled bone removal. The most common complication after surgery is bony exposure (4.5 to 17.5% of cases); restenosis rates are low (1.2 to 6.3%). 1,2 References 1. House JW, Wilkinson EP. External auditory exostoses: Evaluation and treatment. Otolaryngol Head Neck Surg 2008;138(5):672-8. 2. King JF, Kinney AC, Iacobellis SF II, et al. Laterality of exostosis in surfers due to evaporative cooling effect. Otol Neurotol 2010;31(2):345-51. Figure. Otoscopic view shows the exostoses occluding the right external auditory canal.