The paramedial transcavernous approach to the basilar artery. A microanatomical study

A standard pterional craniotomy often does not provide adequate access to the neck of a basilar artery aneurysm or for placement of temporary clip on the parent artery. Various strategies for enhancing this exposure have been described in the literature (Dolene V, Kawase T., AI Mefty O.) In our institution we have adopted a focusing paramedial transcavernous approach between the third and fourth nerve involving the oculomotor trigone and the inferomedial triangle of the cavernous sinus. Five cadaver heads (10 specimens) specifically fixed with formalin, to permit a close to live brain consistency and injected with colored silicone were used in this study. Anatomical dissections were performed in a surgical fashion respecting the constraints commonly encountered in the operating room. The relation of the cavernous sinus durai incisions inherent to this approach to the third, fourth and sixth cranial nerves; carotid artery and petroclinoid folds are described and measured. Finally the additional exposure of the basilar artery gained with this approach was quantified.