Blood supply to the intracavernous cranial nerves: comparison of the endoscopic and microsurgical perspectives.

OBJECTIVE: To provide a comparative description of the endoscopic and microsurgical anatomic features of the blood supply to the cranial nerves in the lateral wall of the cavernous sinus. METHODS: Twenty-four cavernous sinuses were dissected in 12 adult cadaveric heads. Endoscopic observations were made with 0- and 45-degree, 4-mm rod-lens endoscopes. The lateral wall of the cavernous sinus was exposed through an endonasal transsphenoidal approach. The microsurgical observations were performed with a surgical microscope with possible magnification ranging from 4x to 40x through a lateral transcranial approach. Neurovascular relationships in the lateral wall of the cavernous sinus were noted, and the endoscopic and microsurgical perspectives were compared. RESULTS: The neurovascular relationships in the lateral wall of the cavernous sinus that are visible by the endonasal transsphenoidal approach but not visible by the transcranial microsurgical approach are as follows: between the oculomotor nerve and the tentorial artery, between the distal segment of the trochlear nerve and the tentorial artery, between the ophthalmic nerve and the inferolateral trunk, and between the abducens nerve and the inferolateral trunk. The neurovascular relationships visible by the transcranial microsurgical approach but not visible by the transsphenoidal endoscopic approach are as follows: between the oculomotor nerve and the superoproximal artery, when present, and between the proximal segment of the trochlear nerve and the superoproximal artery. CONCLUSION: Incorporating the endoscopic and microsurgical perspectives ensures a better understanding of the neurovascular relationships in the cavernous sinus lateral wall. This information could be relevant for preservation of the blood supply to the nerves during surgery in or around the cavernous sinus.