Laboratory Medicine Summary
No specific laboratory studies are required for this procedure. Routine laboratory work may be recommended based on age and risk factors for undergoing general anesthesia.
In addition to the basic history and neurotologic physical examination including otoscopy, all patients should undergo a preoperative audiogram. This not only allows assessment of the degree of conductive hearing loss that may be present from external auditory canal occlusion but also provides information on any potential pre-existing sensorineural hearing loss.
Imaging Studies
Many situations requiring canalplasty require preoperative computed tomography (CT) imaging of the temporal bone without intravenous contrast. In situations in which the lesion is clearly identified on examination, such as a bony exostosis or benign soft tissue growth, CT imaging may not be necessary.
Staging
A rating scale for external auditory exostosis has evolved primarily for means of comparisons between studies. It is staged on scaled severity from 0-3 based on the percentage of canal obstruction, with 0 representing normal or no obstruction, 1 as less than 33%, 2 as 33-66%, and 3 as more than 66%. [9]
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empty para to satisfy content model
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Cross-section of the middle and inner ear.
