1. Surgical Anatomy of the Paraclinoid Region: Lessons From Many Masters Issam A. Awad, MD, MSc, FACS, MA (hon) Professor of Neurosurgery Northwestern University Evanston Northwestern Health Evanston, Illinois

2. The Paraclinoid Region: Fundamentals for Every Surgeon The anatomic facts: Rhoton’s Canon Implications for paraclinoid aneurysms Implications for surgical approach Maximalist versus minimalist strategies A personal philosophy

3. The Anatomic Facts: Rhoton’s Canon Segments of the internal carotid artery (ICA) Unique anatomic features of the C5-6 segments of the ICA The oculomotor triangle Relations to the optic nerve Anatomy as the surgeon’s safeguard

4. The Anatomic Facts: Rhoton’s Canon Segments of the ICA Fisher Berenstein and Lasjaunias Bouthillier and van Loveren

5. The Anatomic Facts: Rhoton’s Canon Unique anatomic features of the C5-6 segments of ICA

6. The Anatomic Facts: Rhoton’s Canon Unique anatomic features of the C5-6 segments of ICA Hemodynamic stresses Imaging limitations Dural relationships Bony relationships The subarachnoid space

7. The Anatomic Facts: Rhoton’s Canon Unique anatomic features of the C5-6 segments of ICA Hemodynamic stresses Imaging limitations Dural relationships Bony relationships The subarachnoid space

8. The Anatomic Facts: Rhoton’s Canon Unique anatomic features of the C5-6 segments of ICA Hemodynamic stresses Imaging limitations Dural relationships Bony relationships The subarachnoid space

9. Imaging The Paraclinoid Region Kobayashi: Cisternographic Guidance Gonzales, Zabramski and Spetzler: Optic Strut as Reference

10. The Anatomic Facts: Rhoton’s Canon The oculomotor triangle The interclinoid ligament The tentorial edge (anterior petroclinoid ligament) The posterior petroclinoid ligament Relations to Cr. Ns. III, IV and VI

11. The Anatomic Facts: Rhoton’s Canon The oculomotor triangle The interclinoid ligament The tentorial edge (anterior petroclinoid ligament) The posterior petroclinoid ligament Relations to Cr. Ns. III, IV and VI

12. The Anatomic Facts: Rhoton’s Canon Relations to the optic nerve The anterior clinoid process The falciform ligament The optic strut The distal ring The proximal ring

13. The Anatomic Facts: Rhoton’s Canon Anatomy as the surgeon’s safeguard Ease of approach Vascular control Maximize safety Maximize exposure, maneuverability Maximize effectiveness

14. Implications for Paraclinoid Aneurysms The ophthalmic aneurysm The superior hypophyseal aneurysm (extradural versus carotid cave) The ventral paraclinoid aneurysm (transitional versus intradural)

15. Ophthalmic Aneurysm Optic nerve canal decompression + clinoidectomy Endovascular adjuncts Proximal control Suction decompression Intraoperative angiography

16. Ophthalmic Aneurysm

17. IO Angio

18. Superior Hypophyseal Aneurysm

19. Ventral Paraclinoid Aneurysm

20. Clip Intradural Portion, Coil Extradural Portion

21. Maximalist vs. Minimalist Strategies Adaptation of conventional approaches Maximalist skull base approaches Minimalist (keyhole, endoscopic assisted or controlled) Focused strategies

22. A Personal Philosphy: Balancing What is “Safe” and What is “Feasible” Proximal control Intradural versus extradural consideration Endovascular adjuncts Endovascular treatments Future challenges and opportunities -- surgical, endovascular