Fig 4.

Acutely ruptured left vertebral dissecting aneurysm of a dominant vertebral artery in a 36-year-old woman presenting in HH IV (patient #9). A, Angiogram of the dominant left vertebral artery demonstrates a dissecting aneurysm distal to the PICA origin (long arrow) with focal narrowing. Note proximal basilar fenestration (short arrow). B, Right vertebral angiogram during test occlusion of the left vertebral artery shows adequate filling of posterior circulation vessels despite small caliber. C, Unsubstracted radiograph after internal coil trapping of the distal left vertebral artery.