Surgical Access to the Paraclinoid Segment of the Internal Carotid Artery: A Technical Review

Surgical access to the paraclinoid segment of the internal carotid artery is important for safe surgical clipping of paraclinoid carotid aneurysms such as carotid-ophthalmic aneurysms and for surgical treatment of tumors of the anterior clinoid process (ACP), anterior part of cavernous sinus and the wall of the orbital apex. Anterior clinoidectomy is useful during surgical access to the paraclinoid segment of the internal carotid artery (ICA). The extensive surgical field gained after anterior clinoidectomy allows lesser brain retraction and increases mobilization of the intracranial ICA and optic nerve. In this report, the authors describe the anatomy of the internal carotid artery and its various segments. Anatomy of the anterior clinoid process and its relation to the internal carotid artery are reviewed. The basic principles of anterior clinoidectomy, the risks and possible complications are also discussed.