CT Venography: Use in Selecting a Surgical Approach for the Treatment of Petrous Apex Cholesterol Granulomas

Objective: To demonstrate the use of computed tomographic (CT) venography in selecting a surgical approach for cholesterol granulomas. Study Design: Retrospective case review. Setting: Tertiary referral center. Patients: Three patients presented with symptomatic petrous apex cholesterol granulomas with extensive bone erosion involving the jugular fossa. Intervention(s): Computed tomographic venography was performed on each patient before selecting a surgical approach for drainage. Main Outcome Measure(s): Localization of the jugular bulb in relation to the petrous carotid artery and basal turn of the cochlea was ascertained in each subject. Results: Three patients with large symptomatic cholesterol granulomas were identified. Conventional CT demonstrated extensive bone erosion involving the jugular fossa in each patient. The location of the jugular bulb and its proximity to the petrous carotid artery and basal turn of the cochlea could not be determined with conventional temporal bone CT and magnetic resonance imaging. Computed tomographic venography provided the exact location of the jugular bulb in all 3 patients. The favorable position of the jugular bulb in all 3 cases permitted drainage of these lesions using an infracochlear approach. Conclusion: Computed tomographic venography provided invaluable information in 3 patients with large symptomatic cholesterol granulomas. All 3 patients were previously thought to be unsuitable candidates for an infracochlear or infralabyrinthine approach because of the unknown location of the jugular bulb.