Magnified view of a transcondylar craniectomy. The occipital condyle has been drilled and the hypoglossal canal opened to reveal the course of the hypoglossal nerve. The jugular foramen has been drilled to reveal the foraminal segments of the glossopharyngeal, vagus and spinal accessory nerves. The anterior medullary, lateral medullary, and tonsillomedullary segments of the posterior inferior cerebellar artery are visualized with this craniotomy, as are the V3 and V4 segments of the vertebral artery. (Image courtesy of AL Rhoton, Jr.)