Vertebral Artery Mobilization During Transcondylar Extreme Far Lateral Approach for Excision of Large Foramen Magnum Meningioma: 2-Dimensional Operative Video

Abstract

Foramen magnum meningiomas are challenging lesions owing to their proximity to the lower brainstem, vertebrobasilar system, and lower cranial nerves. 1,2 Tumor size, origin, morphology, relationship to neurovascular structures, and bony anatomy determine the optimal surgical approach. 2,3 Classically, far lateral approaches have been the workhorse approach to the foramen magnum. Variations of the far lateral including transcondylar and extended transcondylar (paracondylar), with or without transposition of the vertebral artery, are sometimes used for a more lateral approach to the brainstem and clivus. Here, we present a 60-year-old male patient presenting with a large foramen magnum meningioma. Preoperative workup includes computed tomography and MRI with angiography to assess for posterior circulation dominance, anatomic variants including posterior inferior cerebellar artery origin, venous, and bony anatomy. 1,4 An extreme far lateral provides access anterior to the vertebral artery to extend exposure beyond the standard far lateral approach. This comprised transcondylar drilling, bony mobilization of the V3 Vertebral artery from C1 foramen transversarium, and dural mobilization of vertebral artery with a dural cuff at its site of dural entry. The patient tolerated the procedure, gross total resection was achieved, and the patient was discharged home. This video demonstrates in detail the steps of exposure, condylar drilling, vertebral artery transposition, and dural opening. These maneuvers can be difficult to conceptualize yet are key to successful extended transcondylar exposure. The patient gave informed consent for surgery and video recording. Institutional Review Board approval was deemed unnecessary.