Meningiomas de fosa posterior: nomenclatura con orientación anatomo-quirúrgica y presentación de casos ilustrativos.

Abstract

Introduction

Posterior fossa meningiomas comprise 20% of all meningiomas, being each location associated with a specific approach, morbidity and mortality. The actual classifications are centered on the dural attachment, without associating the anatomical with the surgical aspects, useful to the young neurosurgeon in the formulation of strategies and approaches for its resolution.

Objectives

To present a classification of the posterior fossa meningiomas with an anatomical-surgical view including the presentation of cases.

Materials and Methods

A nomenclature was established concerning previous reports, the anatomical criteria and the surgical experience of the authors. Cases were presented by reviewing the medical records corresponding to each subtype of the proposed classification.

Results

We represent the posterior fossa as a 3 rings compartment: the upper one is divided into medial, anterior-lateral and posterior-lateral; the middle ring is divided into 6 variants: pure clival, spheno-petro-clival, anterior petrosal, posterior petrosal, and medial and lateral suboccipital convexity; the lower ring is divided into anterior, right lateral, left lateral, and posterior.

Conclusion

Superior ring meningiomas can be resolved by a suboccipital or lateral suboccipital approach; middle ring meningiomas have a more diverse spectrum of options; while meningiomas of the inferior ring - following the scheme of division into quadrants of a clock - can be resolved by means of a medial or extreme-lateral suboccipital approach.