[Surgical Approaches to Petroclival Meningiomas Part 1: Microsurgical Anatomy]

Most petroclival meningiomas are benign tumors, but their neurosurgical treatment is one of the greatest challenges in this field. Acquiring a deep practical knowledge of brain anatomy is the first step on the path to successfully meeting this challenge. To this end, the present paper is divided into two parts. The first regards the microsurgical anatomy and surgical approaches used in the management of petroclival meningiomas. The second correlates the brain anatomies of the 30 cases of petroclival meningiomas which the senior author (GRI) has operated on.

Eight cadaver heads were dissected using surgical microscopes at the University of Arkansas microsurgery laboratory. The heads were stabilized in a Mayfield device to simulate surgical conditions and colored silicon was injected to highlight the differences between arteries and veins. The approaches performed were: cranio-orbital zygomatic, posterior and anterior petrosectomy, and retrosigmoid.

Three main surgical approaches were chosen to treat petroclival meningiomas: the pterional approach and its variants, the petrous approach and its variants, and the retrosigmoid approach. To rationalize the choice of approach, the clivus was separated into superior, middle, and inferior thirds.

Several surgical approaches are useful in accessing the petroclival region. Acquiring a practical knowledge of this anatomy in a microsurgical laboratory is fundamental for any surgeon who intends to operate on petroclival meningiomas.