Drainage of a petrous apex cholesterol granuloma through an infracochlear approach

Abstract

The current video presents the surgical management of a cholesterol granuloma of the anterior petrous apex, through the infracochlear approach. The video contains patient's medical history, pre-operative radiological evaluation, surgical approach to the lesion and radiological follow up. Surgery was conducted by an otology and skull base team in a tertiary referral center. The patient is a 49-years-old male, who was referred to our center for a four months history of right tinnitus and fullness. The clinical evaluation was unremarkable and the audiometric testing showed a right sensorineural hearing loss with normal contralateral hearing. A high-resolution CT-scan of the temporal bone was performed showing a lesion occupying the right petrous apex and eroding the cochlea. In a subsequent MRI scan, the lesion appeared hyperintense in both T1- and T2-weighted images. Those radiological features prompted us to the diagnosis of a cholesterol granuloma, and the selected treatment was a drainage via infracochlear approach. The infracochlear approach, firstly described by Giddings et al. [1] in 1991, represents a direct route to the petrous apex, that can be chosen in selected cases with favorable anatomical conditions and that allows respecting of the hearing mechanism. After surgical drainage of the granuloma, no worsening of the pure tone threshold was confirmed by the audiological evaluation. The hospital stay was uneventful and the patient was discharge one day postoperatively. One-year postoperative MRI scan showed signal reduction of the cholesterol granuloma.

Keywords: Cholesterol granuloma; Ear surgery; Petrous apex.