Narrowing of the ear canal is called aural atresia. It can range from a slight narrowing to a complete absence of the external ear canal. When this occurs at birth, we use the term congenital atresia.
There may also be changes in the shape of the outer ear or pinna (termed microtia) as well as malformations of the middle ear structures, including problems with the three bones of hearing. Rarely, there may also be abnormalities of the inner ear structures.
Aural atresia occurs in 1 in 10,000 to 20,000 live births, with atresia of one side being three times more common than atresia of both sides.
Atresia of the ear canal requires evaluation by a multidisciplinary team including an otolaryngologist, audiologist, and radiologist. (Additionally, plastic surgeons may be involved in the correction of any malformations of the outer ear). An absent ear canal leads to a conductive hearing loss even if the inner ear and hearing nerve are normal. In addition to hearing loss, a narrow canal can predispose to infections, or in more severe cases, to cysts or entrapment of skin of the canal and middle ear called cholesteatomas.
In some situations, the ear canal can be surgically reconstructed to improve hearing. Alternatively, bone conduction hearing aids may be an option. Surgery to reconstruct the ear canal (termed atresiaplasty) is typically recommended at 5-6 years of age for patients with atresia of one or both sides. However, in some situations, surgery may be performed before this age. The decision to repair the external part of the ear (microtia repair) and the type of repair used (rib graft technique versus medpor implant) impacts the timing of atresiaplasty. To maintain initial surgical results and to avoid late complications following atresiaplasty, such as narrowing of the ear canal, the patient needs diligent postoperative office care.