Numerous nuanced approaches have been used to access posterior inferior cerebellar artery (PICA) aneurysms for microsurgical clipping. The authors report the case of a patient with a right vertebral artery (VA)–PICA aneurysm that was reached via a contralateral far-lateral approach. The wide-necked saccular/fusiform aneurysm arose from the lateral aspect of the right V4 segment just proximal to the PICA origin, anterior to the jugular tubercle at the level of the hypoglossal canal. Computed tomography angiograms demonstrated the size and configuration of the aneurysm, and 3D reconstructions revealed the tortuosity of the right VA, defining its location just left of the midline adjacent to the lower clivus.
A contralateral far-lateral approach to VA–PICA aneurysms should be considered when aneurysms cross the midline. Computed tomography angiography with volume rendering and interactive software capabilities can help identify the relationship of such an aneurysm to an individual's particular skull base osseous anatomy and is paramount in selecting the optimal microsurgical approach.