Awake Craniotomy for Astrocytoma in the Left Frontal Lobe Using Augmented Reality Superimposing Tumor and White Matter Tracts: 2-Dimensional Operative Video.

ABSTRACT

Augmented reality (AR) is expected to serve as an assistive intraoperative technology in neurosurgery.1 Awake craniotomy (AC) for gliomas benefits the extent of resection, survival, and postoperative neurofunctional outcomes.2 In AC, it is critical to understand the cortical and subcortical anatomy.3 We describe the use of AR superimposing tumor and deep white matter tracts in AC. A 29-year-old right-handed woman presented to a local hospital after an episode of generalized convulsions. MRI of the head revealed a widely spreading tumor in the left middle frontal gyrus. After a left frontal craniotomy while the patient was asleep, AR was used to indicate the tumor boundary with subcortical fibers including the corticospinal tract, inferior fronto-occipital fasciculus, and cingulate fasciculus. We performed AR-assisted removal of the tumor on the surface of the middle frontal gyrus. On subcortical stimulation (SCS) of the frontal aslant tract and inferior fronto-occipital fasciculus, the patient stopped naming objects in the picture-naming test, while SCS of the left cingulate gyrus caused the patient to mistake colors in the Stroop test. The subcortical fibers identified by AR coincided with the sites of symptom elicitation by SCS. We eventually removed a large part of the tumor. Postoperative MRI confirmed 96.2% resection. The patient was discharged without any new neurological deficits. AC with AR is useful for resection of gliomas in the dominant hemisphere. The patient consented to the procedure and to the publication of her image. The ethics committee of our hospital does not require approval for case reports.