Microsurgical Anatomy of the Posterior Wall of the Cavernous Sinus

Background Transcavernous surgical corridors are a valid alternative to lateral approaches to the petroclival area between the posterior clinoid and jugular processes. Limited information is available about the complex anatomy of the posterior wall of the cavernous sinus. We describe in detail the microsurgical anatomy of posterior wall of the cavernous sinus and its dural, bone, and neurovascular relationships.

Methods Microscopic anatomical dissection of the cavernous sinus was performed on five cadaveric specimens. The four borders of the posterior wall of the cavernous sinus were identified and defined with respect to surrounding anatomical relationships.

Results The posterior wall of the cavernous sinus is a layer of dura which separates the cavernous sinus content from the posterior fossa and is bounded laterally by the medial part of Meckel’s cave and medially by the lateral aspect of the sphenoid bone. The complex system of posterior petroclinoid ligaments and the temporal lobe dura contribute to the superior border. The inferior border was identified between foramen ovale, cranial nerve (CN) V3 just medial to the foramen lacerum, and the lateral aspect of the sphenoid bone. The posterior wall of the cavernous sinus is traversed by several neurovascular structures including CNs III and IV superiorly, CN VI superolaterally in Dorello’s canal, and the two main branches of the meningohypophyseal trunk—the dorsal meningeal artery and the artery of Bernasconi and Cassinari—in their courses to the clival dura posteriorly.

Conclusion A clear understanding of the anatomy of the posterior wall of cavernous sinus and its complex anatamoarchitecture is essential to define optimal transcavernous surgical corridors to the middle clival area.