J Korean Neurosurg Soc.  2013 May;53(5):293-296. 10.3340/jkns.2013.53.5.293.

Ruptured Saccular Aneurysm Arising from Fenestrated Proximal Anterior Cerebral Artery : Case Report and Literature Review

  • 1Department of Neurosurgery, Korea University College of Medicine, Seoul, Korea. hermes23@kumc.or.kr


The aneurysm arising from fenestrated proximal anterior cerebral artery (ACA) is considered to be unique. The authors report a case of a 59-year-old woman who presented with a subarachnoid hemorrhage (SAH) secondary to a ruptured aneurysm originating from the fenestrated A1 segment of right ACA. The patient had another unruptured aneurysm which was located at the right middle cerebral artery bifurcation. She was successfully treated with surgical clipping for both aneurysms. From the previously existing literatures, we found 18 more cases (1983-2011) of aneurysms associated with fenestrated A1 segment. All cases represented saccular type of aneurysms, and 79% of the patients had SAH. There were three subtypes of the fenestrated A1 aneurysms depending on the anatomical location, relative to the fenestrated segment. The most common type was the aneurysms located on the proximal end of fenestrated artery (82%). Azygos ACA and hypoplastic A1 were frequently accompanied by the aneurysm (33% and 31%, respectively), and multiple aneurysms were shown in three cases (16%). Considering that fenestrated A1 segment is likely to develop an aneurysm, which has high risk of rupture, early management may benefit patients with aneurysms accompanied by fenestrated proximal ACA.


Anterior cerebral artery; Cerebral aneurysm; Fenestration

MeSH Terms

Aneurysm, Ruptured
Anterior Cerebral Artery
Intracranial Aneurysm
Middle Cerebral Artery
Subarachnoid Hemorrhage
Surgical Instruments


  • Fig. 1 A : Computed tomography scan showing a large intracerebral hemorrhage in right side frontal lobe extending to basal ganglia. Subarachnoid hemorrhage was also identified at the anterior falx and sulci of medial frontal lobes. B : Angiography revealing an aneurysm arising from the proximal end of fenestrated right A1 segment. C : Right cerebral angiogram showing two aneurysms including one on the proximal end of fenestrated A1 and another on the middle cerebral artery bifurcation. Azygos anterior cerebral artery was visible on the angiogram. D : Left carotid angiogram showing that the right A1 segment is aplastic.

  • Fig. 2 Intraoperative photographs exposed by left pterional craniotomy. A : The fenestration of right A1 and a clipped saccular aneurysm on the proximal end of the fenestration. B : Photograph of the unruptured middle cerebral artery bifurcation aneurysm after successful clipping.

  • 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.

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