Three-Dimensional Angiographic Demonstration of Plexiform Fenestrations of the Proximal Anterior Cerebral Artery Associated with a Ruptured Aneurysm

A rare case of ruptured aneurysm associated with multiple A₁ fenestrations resembling plexiform network was demonstrated by 3D angiography. A 56-year-old female presented with a ruptured aneurysm in the A₂ segment of the left distal anterior cerebral artery associated with the right A₁ fenestration. The ruptured aneurysm was occluded with surgical neck clipping via interhemispheric approach without neurological deficit. Plexiform fenestrations of the right distal A₁, opposite side to the left ruptured A₂ aneurysm, were clearly visible on postoperative 3D angiography. Our case may strongly support the theory described by Paget, namely that a remnant of the plexiform anastomosis between the primitive olfactory artery and A₁ segment is the source of such fenestration.