The goal of surgical treatment for cholesterol granuloma of the petrous apex is to establish a permanent drainage route. We report a case managed by the transcanal infracochlear approach. The patient was a 78-year-old man who presented to us with left-sided hearing loss. Pure-tone audiometry revealed sensorineural hearing loss in the left ear. Computed tomography (CT) and magnetic resonance imaging suggested that the lesion in the petrous apex was a cholesterol granuloma. We performed drainage via the transcanal infracochlear approach. The inferior wall of the external auditory canal was drilled to expose the hypotympanum, followed by drilling of the air cells located inferior to the cochlea. The cyst wall was fenestrated and a silicone tube was inserted to maintain drainage. Postoperative CT scan showed an aeration of the cyst cavity. The transcanal infracochlear approach allows direct access to the petrous apex through the external auditory canal because of drilling of the space surrounded by the cochlea, internal carotid artery, and jugular bulb. Based on preoperative CT evaluation, this approach was deemed safe and feasible in our case. This technique may provide a minimally invasive and effective treatment approach for selected patients with cholesterol granuloma in the petrous apex.
Maruta et al. (Thu,) studied this question.