Saccular trilobed aneurysm of azygos anterior cerebral artery

Figure 1 Computerized tomography scan of the year 2008. Second episode of the intracerebral hemorrhage.

Figure 2 Computerized tomography scan of the year 1990. First episode of intracerebral frontal hemorrhage (white arrow).

Figure 3 Preoperative digitally subtracted angiography.

Figure 4 Intraoperative pre-clipping photo. Numbers 1, 2 and 3 refer to respective lobes of the trilobed aneurysm. CM: Calloso-marginal; DACA: Distal anterior cerebral artery/pericallosal artery.

Figure 5 Intraoperative post-clipping photo. Three separate clips exclude the three lobes of the aneurysm.

Figure 6 Postoperative digitally subtracted angiography showing preserved blood flow in the pericallosal artery and the exclusion of the aneurysm.