Use of the O-arm® for skull base resection in a sphenoorbital meningioma.

Intraoperative imaging during skull base surgery allows the surgeon to evaluate surgical results and direct further bone resection prior to closure, avoiding the potential morbidity of inadequate surgical therapy or reoperation. Intraoperative CT (iCT) scanning has become widely available in recent years, but its neurosurgical applications have been limited mostly to spinal and functional operations. We report a patient with a sphenoorbital meningioma with adjacent hyperostosis causing proptosis and optic canal stenosis in which a portable iCT scanner (O-arm(®); Medtronic, Fridley, MN, USA) was used to guide further resection. Postoperatively, the patient experienced resolution of her proptosis, and her vision remains clinically normal. The O-arm(®) can be easily incorporated into standard operating rooms and is useful in tailoring bony skull base resections.