Quantitative Anterior and Posterior Clinoidectomy Analysis and Mobilization of the Oculomotor Nerve during Surgical Exposure of the Basilar Apex Using Frameless Stereotaxis

Background Anterior and posterior clinoidectomies have been proposed to augment exposure of the basilar apex. A sequential quantitative benefit analysis offered by these maneuvers has not been reported. Methods Fourteen datasets from eight cadaveric specimens were analyzed. A modified orbitozygomatic frontotemporal craniotomy was performed. The extent of proximal control of the basilar artery was determined through the exposed opticocarotid and carotidoculomotor triangles before and after clinoidectomies and mobilization of the third nerve at the porous oculomotarius. Results Removal of the anterior and posterior clinoids significantly improved proximal basilar artery access (p Conclusion Anterior and posterior clinoidectomies significantly improved the area of exposure of the opticocarotid triangle, carotidoculomotor triangle, and the exposed length of the basilar artery available for proximal control. This improvement is extremely important for large or giant aneurysms of the upper basilar artery or aneurysms hidden by the posterior clinoid.