A Novel Descriptive Framework for Petroclival and Temporal Bone Meningioma Surgical Outcomes

Petroclival and temporal bone meningiomas are rare neoplasms that mimic vestibular schwannomas in presentation. However, surgical approaches for their resection are often more complex, largely due to the necessity of resecting pathologic dura. Although several classification and staging systems for petroclival meningiomas have been proposed, they are rarely cited and none are reliably correlated with surgical outcomes. We present a descriptive framework and hypothesize that it is predictive of surgical outcomes.

Medical records of patients seen at a tertiary referral center with a diagnosis of petroclival meningioma were reviewed. Patients were stratified into four tiers: tier 1, meningioma confined to internal auditory canal (IAC) only; tier 2, meningioma confined to cerebellopontine angle (CPA) only; tier 3, meningioma involving CPA and IAC; and tier 4, meningioma involving cavernous sinus, internal carotid artery or jugular bulb, or crossing midline. Tier 4 was subdivided into 4A (no carotid involvement) and 4B (carotid involvement). Outcomes of observation, radiation, and surgery were analyzed.

Of 64 qualified patients, tier 2 was most commonly encountered (41%); the remainder of patients were classified as tier 1, 3, and 4 (3%, 33%, 23%). Among patients indicated for resection, combined petrosal approach was utilized in 64% of cases. Simpson grade of resection, complication rate, and rate of residual/recurrent tumor were statistically significantly associated with tumor tier. Tier and postoperative House-Brackmann score showed no significant correlation.

The proposed framework demonstrates the potential clinical utility of an outcome-predictive staging system, helping to guide surgeon and patient expectations.