Anterior Transpetrosal Approach for Trigeminal Schwannoma with Persistent Primitive Trigeminal Artery: 2-Dimensional...

The surgical management of trigeminal schwannomas often requires complicated skull base approaches based on detailed anatomical understanding because of the involvement of multiple compartments of the trigeminal nerve from its root to the peripheral branches. When there is vital anatomical anomaly around the tumor, this can make the surgical management and anatomical understanding more difficult.1,2 This video demonstrates the microsurgical removal of a dumbbell-shaped trigeminal schwannoma via the anterior transpetrosal transtentorial approach in a patient with a persistent primitive trigeminal artery, the most common persistent embryonic carotid-vertebrobasilar anastomosis. A 32-yr-old woman presented with progressive facial sensory impairment, dizziness, and slight diplopia because of right abducens palsy. Neuroimaging revealed a right Meckel's cave tumor extending to both the middle and posterior cranial fossae and displacing the abducens nerve inferomedially. The persistent primitive trigeminal artery, which is an anomalous communication between the cavernous carotid and basilar arteries, was identified ventral to the tumor. While preserving most of the noninvaded trigeminal nerve, gross-total resection was achieved under direct visualization of the abducens nerve and persistent primitive trigeminal artery, piercing the dura of the posterior cavernous sinus and coursing medially along the clivus. The patient's facial sensory impairment and diplopia almost disappeared without new neurological deficits or tumor recurrence during the follow-up period of 1 yr. Three-dimensional reconstructed images demonstrated the anatomical relationship of the tumor, the persistent primitive trigeminal artery, and the extent of osseous drilling of the petrosectomy. Informed consent was obtained from the patient.