Predicting Factors for Outcome in Petroclival Meningiomas Surgery

Objective: We reviewed our experience in petroclival meningiomas surgery in the past 20 years to identify the main predicting factors for outcome. Methods: Out of the series of 85 petroclival meningiomas since 1994, we considered the last 50 cases to avoid bias due to the long time considered and the technological evolution. We evaluated the outcome and the morbidity rate, analyzing the role of the following factors: (1) surgical approach; (2) presence of an arachnoidal membrane around the tumor; (3) consistency; (4) dimension; (5) preoperative clinical status. Results: Gross-total removal (GTR) was achieved in 72% of patients. Morbidity consisted in monohemiparesis in 4% of cases, ataxia in 2% and in various CN palsy. In particular, palsy of CN III was observed in 4% of patients, of CN IV in 16%, of CN VI in 20%, while trigeminal hypoesthesia in 8% and facial paresis in 32%. Monolateral deafness occurred on in 12% of cases and swallowing disturbances in 4%. The main factor associated to GTR without neurological sequelae resulted in the soft consistency, followed to the presence of an arachnoidal layer around the tumor, and the choice of less invasive surgical approaches. The dimension of the tumor and preoperative clinical status resulted less important. Conclusion: The tumor soft consistency resulted in the main predicting factor. Also, the presence of an arachnoidal layer around the tumor and the choice of less invasive or multistaged approach resulted useful to avoid postoperative complications.