Figure 5.

Large aneurysm arising from the vertebral artery involving the origin of the posterior inferior cerebellar artery (PICA), which originates from the aneurysm itself, as depicted in CT angiography (CTA) (A) in a 46-year-old woman with history of remote subarachnoid hemorrhage (SAH). An occipital-PICA bypass graft as seen on CTA (B) was performed in anticipation for coil occlusion of the vertebral artery 3 months following the bypass procedure. The patient has remained clinically intact and the bypass patent for the past 2 years. (Reprinted with permission of Mayfield Clinic.)