Retrosigmoid approach for meningiomas of the cerebellopontine angle: results of surgery and place of additional treatments

Meningiomas of the cerebellopontine angle (CPA), although homogenous in terms of location, present different surgical challenges depending on their site of dural origin and extension. Complete tumor resection sometimes leads to high morbidity. The objective of this work is to evaluate the results of surgery and the place of additional treatments. In a series of 115 patients with CPA meningiomas, we retrospectively studied 69 patients operated on between 1994 and 2007 using a retrosigmoid approach. Clinical presentation, operative findings and functional outcome were reviewed for a mean follow-up time of 36 months. Usual presentation was hearing loss associated with gait disturbance (50%) and vertigo (35%). Preoperative cochlear evaluation was abnormal in 40% of the cases. Most tumors (90%) originated on the posterior face of the petrous part of the temporal bone. In one-third of the cases, the meningioma had invaded the internal acoustic meatus. Total or subtotal tumor removal was achieved in 91% of patients without perioperative mortality. Fourteen patients received additional treatment with radiotherapy or radiosurgery for a small residual tumor, often deliberately left in place to reduce operative morbidity. At long-term follow-up, facial nerve function was preserved in 91% of the cases. Hearing worsened in 17% of patients. The tumor recurred in only one case. The retrosigmoid approach is a safe surgical procedure. The modern management of CPA meningiomas should achieve as complete a resection as possible within reasonable limits, considering that a small residual tumor can be controlled fairly easily with radiosurgery for a relatively long time.