Angiographic classification of aneurysms of the horizontal segment of the anterior cerebral artery

Ten aneurysms of the horizontal portion of the anterior cerebral artery (A₁) were analyzed. These 10 aneurysms were classified into three types according to the mode of the origin of the neck of the aneurysm from the A₁ segment: (a) an aneurysm originating from the junction of the A₁ segment and the lenticulostriate artery, (b) one from the proximal end of the fenestration of the A₁ and (c) one from the top of the A₁ loop (elongation and kinking of the A₁ segment). In these aneurysms, their size, the side of the A₁ segment with an aneurysm, the multiplicity of aneurysms, the coexistence of hypertension, the grade of the patients, the laterality of the subarachnoid blood clots (as seen on computed tomography scans) and surgical outcome were analyzed.