Ruptured Saccular Aneurysm Arising from Fenestrated Proximal Anterior Cerebral Artery : Case Report and Literature Review
A 59-year-old woman was admitted with complaints of a sudden onset of dysarthria and left side weakness. Computed tomography revealed an intracerebral hemorrhage in the right basal ganglia and frontal lobe. Subarachnoid hemorrhage was also identified in the anterior falx and sulci of medial frontal lobes (). Cerebral angiography demonstrated a saccular aneurysm which arised from the proximal end of the right fenestrated A1 segment. The A2 segment of ACA was only visible from the right internal carotid artery. There was another saccular aneurysm at the right middle cerebral artery (MCA) bifurcation which was considered as an unruptured one because of the long distance from co-existing intracerebral hematoma ().\nUnder general anesthesia, the aneurysms were surgically clipped via right pterional craniotomy. A ruptured saccular aneurysm with broad neck was identified on the proximal end of fenestrated A1 segment intraoperatively. An aneurysm was projected anteriormedially and was occluded by Yasargil mini clip. An unruptured MCA bifurcation aneurysm was also treated by surgical clipping and the intracerebral hematoma was removed ().\nThe postoperative course was uneventful, and the patient was discharged without any neurologic deficits.\nIn the literature review, we found 18 cases of aneurysms arising from the fenestrated A1 segment. Characteristics of 19 cases (including present case)-,,,-,-, are summarized in . There were 9 males and 9 females (1 case, not recorded) with a mean age of 49.7 years (range 33-78 years). The sizes of aneurysms were recorded in 7 out of 19 cases, and the mean aneurysm size was 5.05 mm (range 2.9-7.0 mm). Twelve aneurysms were developed at the right side while seven were located at left side. All 19 aneurysms were saccular type and 15 cases (79%) were ruptured. Three among the aneurysms were treated by endovascular interventions, while the other aneurysms except for those three were treated by aneurysm clipping.\nWe could classify the aneurysms into three types based on the arising point of the aneurysm (). Of the 17 cases in which exact location of the aneurysm was described on the original article (including the present case), 14 (82%) aneurysms developed on the proximal end of the fenestrated A1 segment, which was classified as type I. Two cases (12%) were classified as type II which represent the aneurysm located on the midportion of the fenestrated A1. One case (6%) which demonstrated multiple aneurysms including one at the proximal end and another at the posterior aspect of the fenestrated artery was classified as type III. Of the nine reports in which the presence of azygos ACA has been investigated azygos ACA was noted in 3 cases (33%). Hypoplastic A1 or aplasia of A1 was demonstrated in 4 cases (31%) out of 13 cases in which the status of A1 hypoplasia or aplasia were described. In one case, the ipsilateral A1 was hypoplastic while the other three cases represented contralateral hypoplastic A1. Finally, multiple aneurysms were found in 3 cases (16%) including the present case.