Optic Nerve Mobilization as an Alternative to Anterior Clinoidectomy for Superior Carotid-Ophthalmic Aneurysms: Operative Technique.

Abstract

Carotid-ophthalmic aneurysms arise from the internal carotid artery between the distal dural ring and the origin of the posterior communicating artery. The surgical treatment of these aneurysms usually requires anterior clinoidectomy. However, this procedure is not without complications. In the present report, we have described optic nerve mobilization after optic foraminotomy as an alternative to anterior clinoidectomy to clip superior carotid-ophthalmic aneurysms. We have reported the cases of 3 patients with superior carotid-ophthalmic aneurysms who had undergone surgical clipping. Instead of an anterior clinoidectomy, the optic nerve was mobilized after performing optic foraminotomy. The optic canal was carefully unroofed with a 3-mm, high-speed, diamond drill under constant cold saline irrigation to avoid thermal damage to the optic nerve. After incision of the falciform ligament and optic sheath, the optic nerve was gently mobilized with a No. 6 Penfield dissector, facilitating aneurysmal neck exposure and clipping through a widened opticocarotid triangle. The postoperative course was uneventful for all 3 patients, without any added visual defect. Optic nerve mobilization allowed us to safely widen the opticocarotid triangle and dissect the aneurysm off the optic nerve, without the need for clinoidectomy. This alternative technique permitted, not only early decompression of the optic nerve, but also dissection of the arachnoid between the inferior surface of the optic nerve and the superior surface of the ophthalmic-carotid artery and aneurysm dome. Optic nerve mobilization after optic foraminotomy proved to be a safe and relatively easy technique for exposing and treating superior carotid-ophthalmic aneurysms.