Repeat Resection of a Cavernous Malformation of the Optic Nerve/Chiasm via a Frontotemporal Approach: 2-Dimensional Operative Video

Cavernous malformations are benign vascular lesions that can arise throughout the central nervous system. The occurrence of a cavernous malformation within the optic nerve or chiasm, however, is extremely uncommon. The case described in this video involved a 36-yr-old woman who presented 3 mo after undergoing a left frontotemporal craniotomy for resection of an optic nerve cavernous malformation. She had initially presented to an outside hospital with vision loss, and the left optic nerve lesion was identified and resected. Although her vision had reportedly improved slightly postoperatively, she awoke 3 mo later with bilateral subjective blurriness and new visual field deficits. Magnetic resonance imaging revealed enlargement of the left optic apparatus hemorrhagic lesion, corresponding to residual cavernous malformation. Given the recurrence of hemorrhage and the associated visual symptoms, the patient underwent a redo left frontotemporal craniotomy for resection of the optic nerve and chiasmal lesion. Histopathologic evaluation revealed thick-walled vessels with focal intervening glial tissue, an absence of neoplastic cells, and hemorrhage, consistent with a cavernous malformation. The patient tolerated the procedure well. Postoperatively, she experienced immediate amelioration in her visual symptoms. She was discharged home on postoperative day 3, and her bitemporal visual field deficit continued to progressively improve through her last ophthalmologic appointment 14 mo after surgery. Postoperative and subsequent surveillance neuroimaging demonstrated complete resection of the cavernous malformation without evidence of recurrence. This case demonstrates the techniques utilized to ensure complete resection of the malformation in this very eloquent region. The patient provided consent for publication.