Fig. 3.

Classification of fenestrated proximal anterior cerebral artery aneurysms based on the location of the aneurysm. 14 aneurysms (82%) were located on the proximal end of the A1 fenestration, which was classified as type I. 2 cases (12%) were arising from the trunk of the fenestrated A1, which was determined as type II. A single case which was demonstrated multiple aneurysms including one at the proximal end and another at the posterior aspect of the fenestrated A1, was classified as type III. Two cases were excluded from the analysis because the exact location of the aneurysm was not described clearly in the original article. A-comm : anterior communicating artery, ICA : internal cerebral artery, M1 : M1 segment of middle cerebral artery.