Microsurgical Resection of Fourth Ventricle Subependymoma: 3-Dimensional Operative Video

Abstract

Subependymomas are indolent, low-grade gliomas that comprise approximately 1% of all intracranial tumors. Typical locations are the fourth ventricle in 75% of cases, lateral ventricles, and rarely in the spinal cord. In the fourth ventricle, the tumor commonly arises from the floor, obtaining a polypoid growing pattern that promotes compression and adhesion of adjacent structures such as choroid plexus, medullary velum, nodule, and uvula. Arterial adhesions to tonsilobulbar and telovelotonsilar segments of PICA can be a challenge, increasing bleeding, and ischemia risk. We present a 53-year-old patient with a history of 3 months of progressive occipital headache associated with swallowing difficulty that started 20 days before hospital admission. Physical examination showed a slight uvula deviation. A neurological investigation by magnetic resonance imaging revealed an exophytic fourth ventricle tumor. The patient underwent resection with evoked potential monitoring through a suboccipital approach. The lesion was resected entirely without symptoms worsening. Pathology examination confirms subependymoma diagnosis. In this 3-dimensional video, the authors present a step-by-step microsurgical technique to perform a fourth ventricle subependymoma resection. The patient signed the institutional consent form, which allows the use of his/her images and videos for any medical publications in conferences and/or scientific articles.