LAUSR

Thalamic glial tumors are rare and represent around 1% to 5% of all brain tumors. Surgical removal is the first step in the treatment of these lesions, and total surgical removal is still the most effective treatment that improves the overall survival. However, being embedded within the critical neurovascular structures renders the thalamus a challenging surgical target. In this 3-dimensional video, we present posterior interhemispheric subsplenial approach in the lateral oblique position, in which the thalamus is reached directly without a cortical or callosal incision. A 51-year-old man presented with temporary episodes of double vision. Cranial magnetic resonance imaging (MRI) revealed a left-sided pulvinar-thalamic lesion that has a peripheral enhancing zone with a nonenhancing hypointense center. After patient consent was obtained, the patient was placed lateral with the head rotated 30o to the ipsilateral side. This positioning creates the advantage of gravity retracting the occipital lobe. Therefore, the tumor was reached without any rigid retraction of themedial occipital lobe. The splenium of the corpus callosum, galenic venous system, internal cerebral veins, and posterior cerebral artery branches were all kept intact. The highdefinition neuroendoscope was a very useful adjunct to check the residual lesion and hemostasis. Postoperative early and late MRIs showed macroscopic total resection of the tumor. The patient had no postoperative deficit. Pathological studies revealed “anaplastic oligoastrocytoma” (World Health Organization Grade III). The patient received radiotherapy and after 30 months of follow-up, he still has no recurrence. Watch now at https://academic.oup.com/ons/article-lookup/doi/10.1093/ons/ opx012