Surgical experiences of anterior petrosal approach for skull base tumor resection in a single institution

The middle fossa approach has undergone several modifications to expand its exposure along the cerebellopontine angle, petrous apex, tentorium and clivus. The middle fossa anterior transpetrosal approach, so called Kawase’s approach, is designed for the anterior cerebellopontine angle, the ventral surface of pons, and the upper clivus. The purpose of the study is to summarize the surgical experiences of anterior petrosal approach for the treatment of skull base tumor performed by a neurosurgeon. Eight patients (6 women and 2 men) underwent frontotemporal craniotomy and anterior petrosal approach for skull base tumor resection. They included 3 trigeminal schwannomas, 3 meningiomas, 1 chondroma, and 1 metastasis. The median age was 57.5 years (range, 43-72). Three patients with trigeminal schwannomas and 1 patient with chondroma achieved total resection using the classic anterior petrosectomy without dura opening. For petroclival meningioma, opening of posterior fossa dura and coagulation of petrosal sinus was additionally performed. However, surgical corridor was limited anteriorly by mandibular nerve, laterally by internal auditory canal, and posteriorly by tentorium. Neurological deterioration developed postoperatively in 2 patients with petroclival meningioma. It is suggested that anterior petrosal approach is suited for accessing middle fossa lesions with smaller petroclival components.