[Surgical approaches to petroclival meningiomas Part 2: narrative review of what we learned with 30 cases]. / Abordajes quirúrgicos de los meningiomas petroclivales Parte 2: revisión narrativa y lo que aprendimos con 30 casos.

Background: The surgical ressection of petroclival meningiomas is challenging due to its deep location and relationship with vital neurovascular structures. Usually they are benign injuries, but they can involve or infiltrate skull base bones, dura mater and brainstem. This makes the total removing very difficult or impossible without causing neurological deficits. The objective of this study is to review the surgical approaches used on the treatment of petroclival meningiomas and the knowledge which we achieved upon the surgical management of 30 cases. Methods: Series of 30 petroclival meningioma-cases. In the beginning of our series we used petrous approach for all the cases, however, with the acquiring of experience, we are indicating the retrosigmoid approach, leaving the petrous and skull-orbito-zigomatics approaches for selected cases. Results: Owing to the difficulty of the access, the petroclival meningiomas usually require different surgical approaches and have distint surgical difficulties. There are three main approaches: fronto-orbito-zigomatics and variants; petrous and variants and retrosigmoid, and they can be combined. The choice for a surgical approach is usually on the location and size of the tumor, on the skull shape, the involvement of venous structures and according to the surgeon´s experience. Conclusion: Petroclival meningiomas are rare and complex on the skull base. The adequate choice is crucial to achieve the good surgical result.

[Surgical Approaches to Petroclival Meningiomas Part 1: Microsurgical Anatomy]. / Abordajes quirúrgicos de meningiomas petroclivales parte 1: anatomía microquirúrgica.

Background: 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. Methods: 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. Results: 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. Conclusion: 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.