Elongated, finger-like ophthalmic segment aneurysms: Implications for selection of treatment modality

Abstract

BackgroundMicrosurgical treatment of ophthalmic segment aneurysms often requires anterior clinoidectomy and optic nerve mobilization prior to successful clipping. ObjectiveWe hypothesize that ophthalmic segment aneurysms that are elongated and finger-like grow unconstrained, lateral to the optic nerve. We note that this avoids the need for clinoid resection and optic nerve mobilization. MethodsThree cases with up-pointing aneurysms were reviewed. Patient and aneurysm characteristics were collected. ResultsThe first two patients with elongated ophthalmic segment aneurysms were found to have aneurysms growing lateral to the optic nerve. This allowed for straightforward treatment via microsurgical clipping without anterior clinoidectomy or division of the falciform ligament. The third patient presented with distortion of the optic chiasm superiorly and medially by a giant ventral ICA aneurysm. A concomitant ophthalmic aneurysm in this patient exhibited elongated morphology, with a high-resolution MRI demonstrating the patient’s optic nerve was located inferior and medial to the ophthalmic artery aneurysm dome. This supports our hypothesis that an overriding optic nerve normally impedes vertical growth of ophthalmic segment aneurysms. ConclusionsOphthalmic segment aneurysms may acquire a round morphology when their growth is constrained superiorly by the optic nerve. Elongated ophthalmic segment aneurysms may be the result of growth lateral to the optic nerve. For these aneurysms, an anterior clinoidectomy is not required, and microsurgical clipping represents a straightforward treatment option.