Microsurgical Resection of the IV Ventricle Subependymoma: 2-Dimensional Operative Video

In this video, we demonstrate microsurgical resection of IV ventricle subependymoma. To the best of our knowledge, this is the first video case report of a microsurgical resection of subependymoma of the IV ventricle in the peer-reviewed English literature. Subependymomas are benign central nervous system tumors, typically arising in ventricular spaces, mostly in the IV and lateral ventricles.1-3 They are isointense on T1 and hyperintense on T2-weighted magnetic resonance imaging (MRI) with minimal or no enhancement.4 Microsurgery remains the mainstay treatment. Complete tumor resection is possible and curative with excellent prognosis.1,5-7 Although the clinical course appears benign, the inability to diagnose them radiographically with certainty and the possibility of an alternative malignant lesion support a low threshold for early and safe resection.8 A 39-yr-old man presented with severe headache and balance problems. Pre- and postcontrast neuroaxis MRI revealed a centrally located IV ventricle lesion without hydrocephalus. The aim of the surgery was complete tumor resection. Surgery was performed in the prone position by the senior author (KIA) with intraoperative neurophysiology monitoring. A small suboccipital craniotomy and C1 posterior arch removal was done. After opening the dura and arachnoid membrane, the tumor was identified and meticulously dissected from the adjacent posterior inferior cerebellar artery and the floor of the fourth ventricle and from brain stem white matter at the tumor-neural tissue interface to avoid brainstem interference. Histological analysis revealed subependymoma (World Health Organization Grade I). Postoperative pre- and postcontrast MRI revealed complete resection. Headache and balance problems completely resolved; the patient was neurologically intact. The patient provided written consent and permission to publish his image.