FIG 2. Patient 27.

A, Anteroposterior angiogram of the left vertebral artery shows irregular narrowing of the supra-PICA segment (arrow) and a pseudoaneurysm at the vertebrobasilar junction (arrowhead). The anterior spinal artery and left PICA are not included in the abnormal segment.

B, Anteroposterior angiogram of the right vertebral artery shows a codominant vessel with full delineation of the vertebrobasilar junction pseudoaneurysm (arrowhead). The dissection extends in the basilar artery to include the AICA origins (arrow).

C, Posttreatment angiogram of the right vertebral artery shows coil occlusion of the vertebrobasilar junction pseudoaneurysm (arrowhead).

D, Posttreatment angiogram of the left vertebral artery shows proximal occlusion of the supra-PICA segment of the vessel with preservation of flow in the anterior spinal artery (arrow) and PICA.