Endoscopic endonasal inferior transclival approach, intradural stage. A medial condylectomy or far medialtranscondylar approach has been performed, providing direct access to the dural entry point of thevertebral artery. The hypoglossal nerve rootlets run postero-lateral to the vertebral artery to enterthe hypoglossal canal, where they merge to form the hypoglossal nerve. Note the location of theventral root of C1, which contrary to the hypoglossal nerve rootlets, is positioned anterior to thevertebral artery. The jugular tubercle is located above the hypoglossal canal, and blocks access to thelateral cerebello-medullary cistern and lower cranial nerves. (Image courtesy of JC Fernandez-Miranda)