Introduction: Previous cadaveric studies suggested up to 18% of the ophthalmic arteries to arise proximal to the dural ring and considered extra dural intra-cavernous Our experience with 200 paraclinoid aneurysms was different, here we reported our findings

Methods: We reviewed 200 cases of paraclinoid aneurysms that underwent direct microsurgical clipping and required removal of anterior clinoid and excision of the dural ring to expose the ophthalmic artery. Data was recorded, the origin of the ophthalmic artery related to the dural ring was analyzed

Results: Two patients out of 200 had a very proximal origin which incorporated the dural ring. The remaining patients the ophthalmic artery originated from the carotid artery proximal to the dural ring

Conclusions: Our microsurgical experience contradicts previous anatomic reports and we suspect that the discrepancy is due to faults in the cadaveric dissection Clarifying this issue will help in preventing injury to the ophthalmic artery during the surgical management of paraclinoid aneurysms

Patient Care: minimizing the incidence of injury to the ophthalmic artery during microsurgical procedures in the paraclinoid region

Learning Objectives: By the conclusion of this session, participants will understand the anatomy of the paraclinoid region and origin of the ophthalmic artery

References: 1- Huynh-Le P, Natori Y, Sasaki T. Surgical anatomy of the ophthalmic artery: its origin and proximal course, Neurosurgery. 2005 Oct;57(4 Suppl):236-41 2- Krisht AF. Transcavernous approach to diseases of the anterior upper third of the posterior fossa. Neurosurg Focus. 2005 Aug 15;19(2):E2. 3- Krisht, Ali F. MD; Hsu, Sanford P.C. MD, Paraclinoid Aneurysms: Part I:superor (True Ophthalmic) Aneurysms, Contemporary Neurosurgery: 31 August 2008 - Volume 30 - Issue 17 - p 1–5