Far lateral transcondylar transtubercular approach to lesions of the ventral foramen magnum and craniovertebral junction

The craniovertebral junction, which consists of the lower one third of the clivus, the foramen magnum, and the CI and C2 vertebrae, is a common site for neoplastic, vascular, congenital, and degenerative lesions of the cranial base. The far lateral transcondylar transtubercular approach (commonlyreferred to as the "far lateral approach") provides excellent exposure and a lateral viewing trajectory for accessing intradural and extradural lesions located at the ventral foramen magnum and craniovertebral junction, avoiding the need for brain retraction (Figure 1). It usually includes a lateral suboccipital craniectomy, a CI hemilaminectomy, partial resection of the posteromedial one third of the occipital condyle, and partial resection of the jugular tubercle. The degree of bone removal is tailored for the individual patient, depending on the location and pathology of the lesion. The far lateral approach is useful for several types of tumors in this region, including foramen magnum menin-giomas, schwannomas, chordomas, and chondrosarcomas. Vascular lesions, such as vertebral artery-posteroinferior cerebellar artery (PICA) junction aneurysms, vertebrobasilar junction aneurysms, and ventrolaterally located brainstem cavernous malformations, also are readily accessed with this approach. This article discusses the technical details and operative nuances of the far lateral approach with transcondylar and transtubercular extensions.