A keyhole middle fossa approach to large cholesterol granulomas of the petrous apex

OBJECTIVE In this article we review our surgical experience in a series of eight pati ents with large cholesterol granulomas of the petrous apex extending into t he cerebellopontine angle. METHODS All lesions, four primary and four recurrent, were studied with magnetic re sonance imaging (MRI), and computed tomography (CT), The patients underwent pre- and postoperative audiographic testing. A keyhole middle fossa approa ch was used in all cases. RESULTS There was no mortality, Surgery was complicated in one case by a subgaleal hematoma and in another by a transitory increase of a preexisting facial pa lsy. In five cases the granuloma was totally resected, whereas in the remai ning three small remnants of the pseudocapsule were left in place. At follo w-up (12-90 months), three patients were asymptomatic. In the remaining fiv e patients, trigeminal neuralgias had subsided. Palsies of the VIth cranial nerve recovered more consistently than those of the VIIth. Hearing was unc hanged postoperatively. So far, there has been no clinical or radiological evidence of a recurrence. CONCLUSION Large cholesterol granulomas of the petrous apex can be effectively treated through a keyhole middle fossa approach, Despite its contained size the ap proach allows a rather large exposure of the granuloma, The resection of th ese lesions carries a low risk of compromising the facial or hearing functi on of the patient. Small remnants of the capsule, left in place to avoid po tential complications, seem not to affect the long-term outcome of the pati ents, provided the cavity in the petrous bone is adequately ventilated. (C) 2000 by Elsevier Science Inc.