Aneurysms of the Fenestrated Anterior Cerebral Artery

Report of Two Cases

Abstract

The authors describe two cases of aneurysms arising from the proximal end of the fenestrated anterior cerebral artery.
Case 1: A 43-year-old male suddenly developed severe headache. Angiography demonstrated an aneurysm arising from the proximal end of the fenestrated anterior cerebral artery, and the neck of the aneurysm was clipped. The patient expired due to vasospasm. On autopsy, medial defects were noted in the neck and dome of the aneurysm. Case 2: A 70-year-old female experienced a sudden onset of severe headache and vomiting, followed by consciousness disturbance. CT scan revealed a high density area in the left Sylvian fissure cistern. Left carotid angiography disclosed the presence of aneurysms at the fenestrated anterior cerebral artery and the middle cerebral artery. Based on the CT findings, it was considered that the aneurysm of the middle cerebral artery had ruptured. Surgery was not performed because of complications.
Angiographic demonstration of the fenestrated anterior cerebral artery has been rare, with only 8 reported cases, and only 1 autopsy case of aneurysm on the fenestrated anterior cerebral artery has been known. From the histological and hemodynamic standpoints, the mechanism involved in the development of such aneurysms is considered to closely resemble that of common saccular aneurysms.