High-Resolution CT Findings in Children with a Normal Pinna or Grade I Microtia and Unilateral Mild Stenosis of the External Auditory Canal

Abstract

SUMMARY:A subset of patients presents with unilateral conductive hearing loss, a normal pinna or grade I microtia, and mild external auditory canal stenosis. The physical findings of microtia and a small external canal are commonly absent or subtle in this group of patients, who are being commonly referred for imaging to evaluate isolated conductive hearing loss. We present a case series of patients with unilateral conductive hearing loss and characteristic ossicular abnormalities, commonly anterior fixation of the malleus. All patients had a significantly increased distance from the cochlear promontory to the handle of the malleus and an abnormal incudostapedial angle, indicative of an abnormal ossicular position and/or morphology. Successful surgical reconstruction of the ossicular chain was attempted and accomplished in 3 patients. ABBREVIATIONS:CHL ϭ conductive hearing loss; EAC ϭ external auditory canal; HRCT ϭ high-resolution CT

A Case of Familial External Auditory Canal Atresia

“…Congenital aural atresia (CAA) is a rate malformation of the ear, occurring in 1 of 10,000 newborns (3). Its characteristics may vary from a narrow external auditory canal and hypoplasia of the tympanic membrane, and a cleft in the middle ear to complete absence of middle ear structures and anotia (2).…”

High-resolution computed tomography evaluation of congenital aural atresia – how useful is this?

“…This accounts for the association between external auditory canal abnormalities and microtia patients. 14 External auditory canal atresia is more common than stenosis, and among atretic ears, bony atresia is more common than membranous atresia. Similar conclusions were made in studies by Takegoshi et al 15 and Swartz and Faerber.…”