Abstract
We report 3 cases of the ruptured anterior communicating artery aneurysm growing in the fenestration of the anterior communicating artery (ACoA). In preoperative angiography, it was difficult to demonstrate the whole images of an aneurysm including the neck. The body of an aneurysm was partially divided by the distal ACoA. The posterior part of an aneurysm is larger than the anterior one and projected posteriorly in all cases. The distal ACoA made a string with no blood flow in 2 cases.
In the operation, the neck dissection is relatively difficult because of the existence of the distal ACoA near the neck of the aneurysm. It was necessary to cut the distal ACoA in 1 case and trap the right Al portion with the aneurysm in another case. The body of an aneurysm was clipped on each side of the fenestration in the other case.
These aneurysms with the fenestration of the ACoA were considered to be difficult for clipping. Great care must be taken to clipping procedures for the complete obliteration of such aneurysms.