Ruptured fusiform aneurysm of the proximal anterior cerebral artery (A1 segment)

A 42-year-old man presented with a ruptured fusiform aneurysm of the proximal anterior cerebral artery (A(1) segment) manifesting as sudden onset of severe headache. Brain computed tomography revealed subarachnoid hemorrhage in the basal cisterns, and left carotid angiography demonstrated a fusiform aneurysm of the left A(1) segment. He underwent surgery via the left pterional approach. The left A(1) segment exhibited a fusiform configuration. Adequate development of the anterior communicating artery was confirmed. Trapping of the aneurysm was performed. The aneurysm was associated with atherosclerotic changes. The postoperative course was uneventful, and the patient was discharged without neurological deficits 1 month after surgery. Fusiform aneurysm of the A(1) segment is quite rare, and tends to bleed, so must be treated. The atherosclerotic origin indicates long-term follow up to identify subsequent lesions.     

Fusiform aneurysm of the anterior cerebral artery (A1 segment)--a case report

A very rare case of fusiform aneurysm of A1 segment of the anterior cerebral artery is reported. A 54-year-old man was admitted with dull headache and speech disturbance for 6 days before admission. CT scan revealed hypertensive subcortical small hemorrhage in the left temporal lobe. Angiography showed no vascular lesion concerning to the subcortical hemorrhage in the left temporal lobe, but showed a spherical aneurysmal dilatation in the left A1 segment of the anterior cerebral artery. At operation a fusiform aneurysm of the left A1 segment was confirmed. The aneurysm was obliterated, and new parent artery was reconstructed using a curved and a straight Yasargil aneurysm clips. The postoperative course was uneventful. Surgical treatment should be directed toward exclusion of large fusiform aneurysm and arteriosclerotic saccular aneurysm from cerebral circulation.     

Two cases of ruptured fusiform aneurysm of the proximal anterior cerebral artery (A1 segment)

Two rare cases of fusiform aneurysms of A1 segment of the anterior cerebral artery are reported. Case 1: A 62-year-old woman was admitted with sudden onset of severe headache and loss of consciousness, on August 22, 1982. CT scan showed subarachnoid hemorrhage at the basal cisterns. Left carotid angiography revealed a spindle shaped aneurysmal dilatation in the A1 segment of the anterior cerebral artery. Four-vessel angiography was performed twice but no other aneurysm was found. She was treated conservatively and the clinical course was not eventful. She was discharged with no neurological deficit one month after the admission. Case 2: A 49-year-old man complained of sudden onset of severe headache, nausea and vomiting on August 24, 1986. He was transferred to a local hospital and CT scan showed subarachnoid hemorrhage at the basal cisterns. Angiography revealed a fusiform aneurysm of the proximal anterior cerebral artery. He was referred to our hospital on the day of onset. He was operated on via bifrontal interhemispheric approach. The fusiform aneurysm of A1 segment was trapped successfully using temporary occlusion of A1 and A2 bilaterally under the administration of Sendai-Cocktail. V-P shunt was performed 1 week after the aneurysmal operation. The post-operative course was uneventful. He was discharged with no neurological deficit three months after operation. As far as we know, there are 6 cases of fusiform aneurysm of A1 segment of anterior cerebral artery in the literature. In this report, our two cases were described and treatment of such aneurysms were discussed.     

Characteristics and surgery of aneurysms of the proximal (A1) segment of the anterior cerebral artery

AIM: Proximal anterior cerebral artery (A1) aneurysms are considered to be rare or even unique. Proper surgical planning around A1 segment is particularly essential in order to avoid injury of tiny perforating arteries. METHODS: In 17 patients with angiographically or intraoperatively diagnosed A1 aneurysms, representing 0.8% of 2 124 aneurysm patients treated surgically at our institution between 1991 and 2003, clinical presentation, neuroradiological findings, surgical treatment methods and outcome were retrospectively analyzed. RESULTS: Sixteen patients presented with subarachnoid hemorrhage; A1 aneurysms were ruptured in 13 cases. Five patients (29%) had multiple aneurysms. In all cases A1 aneurysms were saccular and their maximum diameter ranged from 4 to 25 mm, average, 7.2 mm; in 4 cases they projected from the origin of the perforating artery, in 6 at the bifurcation of the internal carotid artery, in 5 at the anterior communicating artery and in 2 from the convexity of the parent artery. In 15 patients aneurysms were clipped via ipsilateral pterional approach and in the remaining 2, including a case with a second middle cerebral artery aneurysm, through contralateral approach. Eleven patients had excellent outcome, three good, and three died. CONCLUSIONS: Angiograms must be thoroughly analyzed to correctly assess origin of the aneurysmal neck, and to plan the operative procedure as radiological presentations of distal or proximal A1 lesions resemble those of anterior communicating artery and internal carotid artery bifurcation aneurysms, respectively. Contralateral approach may facilitate surgical elimination of selected A1 aneurysms or enable one-stage clipping in patients with multiple bilateral aneurysms.     

A case showing the infraoptic course of the anterior cerebral artery associated with anterior cerebral artery aneurysm

A ruptured anterior cerebral artery aneurysm with anomalous right infraoptic course of the anterior cerebral artery (ACA) was reported. A 40-year old male was admitted because of SAH episode, and computerized tomography (CT) on the day of admission revealed hemorrhage in both Sylvian and interhemispheric fissures. Four-vessel angiography was performed on the same day. A saccular aneurysm was demonstrated in the region of the anterior communicating artery (ACoA), and anomalous artery, which originated from the intradural right carotid artery at the level of the right ophthalmic artery was found to be running medially and superiorly. It supplied the bilateral callosomarginal arteries and the unpaired pericallosal artery. The fenestration of the vertebral artery, duplication of bilateral superior cerebellar arteries, and an occipital artery arising from the right internal carotid artery at the C3 level were found. Surgery was performed on the first day of admission, and the anterior interhemispheric approach was selected. The anomalous branch of the right ICA ran beneath the right optic nerve, ascended between the optic nerves, and supplied the ACoA system. The left hypoplastic A1 segment entered the ACoA. However, the right A1 segment could not be found. The aneurysmal neck, situated between the bilateral callosomarginal arteries and the unpaired pericallosal artery, was clipped with Sugitas curved clip. The postoperative course was uneventful and a follow-up angiograph revealed successful obliteration of the aneurysm.     

Agenesis of the left internal carotid artery associated with right anterior cerebral artery A1 segment bifurcation aneurysm: a case report.

Agenesis of the internal carotid artery occurs in less than 0.01% of the population. Intracranial aneurysms accompany agenesis in 25-43% of the patients. We present a unique patient with a saccular aneurysm of the anterior communicating artery associated with agenesis of contralateral internal carotid artery.     

A neurosurgical view of anatomical variations of the distal anterior cerebral artery: an anatomical study

OBJECT: The vascularization pattern of the anatomy of the distal anterior cerebral artery (ACA) remains a subject of debate. The authors provide detailed information about the distal ACA and shed light on issues concerning it that have not previously been adequately discussed. METHODS: Fifty adult human brains (100 hemispheres) were obtained during routine autopsies. Cerebral arteries were separately cannulated and injected with latex. The vascularization patterns of the cortical branches and the variations of the arteries were investigated. The authors found that the distal ACA supplied all the inner surfaces of the frontal and parietal lobes and a median of one third of the outer surfaces. The origin of the arteries from the main trunk and their exit angles affected the vascularization patterns of the hemispheres. The authors redefine controversial terminology regarding the callosomarginal artery. CONCLUSIONS: In each hemisphere, the vascularization pattern of the distal ACA is different to a greater or lesser extent. An awareness of this fact will contribute significantly to surgical interventions.     

Balloon angioplasty of the A1 segment of the anterior cerebral artery narrowed by vasospasm. Technical note.

The authors describe a new endovascular technique that improves catheterization and balloon angioplasty of the A1 segment of the anterior cerebral artery after it has been narrowed by vasospasm. The technical results of using this method in seven patients are presented.     

Surgically verified variations in the A1 segment of the anterior cerebral artery. Report of two cases.

Two patients with rare variations of the A1 segment of the anterior cerebral artery are presented. One patient had a perforation of the optic tract by an abnormal course of the A1 segment, and the other harbored an aneurysm of the A1 segment running below the optic nerve. The authors present a summary of A1 segment variations described in the literature.     

Aneurysm of distal anterior cerebral artery associated with azygos anterior cerebral artery

Summary An aneurysm arising from the distal anterior cerebral artery distal to the bifurcation of the azygos anterior cerebral artery is reported. A review of the literature emphasizes the rarity of this lesion.     

Trapping and vascular reconstruction for ruptured fusiform aneurysm in the proximal A1 segment of the anterior cerebral artery

A 65-year-old woman presented with subarachnoid hemorrhage (SAH). Angiography detected a small bulge in the A1 segment of the right anterior cerebral artery (ACA). The patient was managed conservatively. Ten days after the initial SAH, the patient suffered a second SAH. Cerebral angiography demonstrated a fusiform aneurysm in the right A1 segment and vasospasm in the left A1 segment. The aneurysm of the right A1 segment was trapped and the right superficial temporal artery (STA) was end-to-end anastomosed to the distal portion of the right A1 segment. The patient had no postoperative cerebral ischemic events. Postoperative cerebral angiography revealed that the bypass flow through the right STA perfused the right ACA territories. STA-A1 end-to-end anastomosis can prevent cerebral ischemic events following parent vessel occlusion or microsurgical trapping for fusiform cerebral aneurysms in the A1 segment without sufficient collateral flow to the ipsilateral ACA territory from the contralateral ACA.     

Angiographic classification of aneurysms of the horizontal segment of the anterior cerebral artery

Ten aneurysms of the horizontal portion of the anterior cerebral artery (A1) were analyzed. These 10 aneurysms were classified into three types according to the mode of the origin of the neck of the aneurysm from the A1 segment: (a) an aneurysm originating from the junction of the A1 segment and the lenticulostriate artery, (b) one from the proximal end of the fenestration of the A1, and (c) one from the top of the A1 loop (elongation and kinking of the A1 segment). In these aneurysms, their size, the side of the A1 segment with an aneurysm, the multiplicity of aneurysms, the coexistence of hypertension, the grade of the patients, the laterality of the subarachnoid blood clots (as seen on computed tomography scans) and surgical outcome were analyzed.     

Aneurysm in the horizontal segment of the anterior cerebral artery confirmed by cerebral vasospasm--case report.

A rare aneurysm in the horizontal segment (A1) of the right anterior cerebral artery was found in a 58-year-old male presenting with subarachnoid hemorrhage. No obvious bleeding source was observed on the day of onset, but 7 days later, a definite diagnosis was made based on the discovery of cerebral vasospasm by a repeat angiogram. The aneurysm was clipped via the right frontotemporal approach 15 days after onset. He suddenly developed neurological symptoms such as consciousness disturbance, right hemiplegia, and aphasia on the 4th postoperative day, when remission of the cerebral vasospasm was confirmed by transcranial Doppler ultrasound examinations and cerebral angiography. The ischemic symptoms were probably due to cerebral embolus caused by intraluminal thrombi, which had formed during the maximum phase of vasospasm and became detached during the remission phase.     

Aneurysms arising from the proximal (A1) segment of the anterior cerebral artery. A study of 38 cases.

This study reviews aneurysms of the proximal segment (A1) of the anterior cerebral artery in 38 patients (23 men and 15 women) and their surgical, angiographic, and clinical management. Thirty-seven aneurysms were saccular and one was fusiform. The incidence of A1 aneurysms among a total of 4295 aneurysm cases treated was 0.88%. Multiple aneurysms occurred in 17 patients (44.7%) of the 38 cases; in 10 (58.8%), there was bleeding from the A1 aneurysm. The aneurysms were classified into five categories according to the mode of origin of the aneurysm in relation to the A1 segment: in 21 cases, aneurysms originated from the junction of the A1 segment and a perforating artery; in eight, from the A1 segment directly; in six, from the proximal end of the A1 fenestration; and in two, from the junction of the A1 segment and the cortical branch. One patient had a fusiform aneurysm. Computerized tomography (CT) of these aneurysms revealed bleeding extending to the septum pellucidum similar to that of anterior communicating artery aneurysms. When performing radical surgery it is very important to recognize the characteristics of A1 aneurysms, including multiplicity, a high incidence of vascular anomalies (especially A1 fenestration), and their similarity to anterior communicating artery aneurysms on CT.     

Dissecting aneurysms at the A1 segment of the anterior cerebral artery--two case reports

Two rare cases of dissections which involve the anterior cerebral artery (ACA) are reported. A 58-year-old woman presented with a ruptured dissecting aneurysm manifesting as sudden onset of severe headache and consciousness disturbance followed by aphasia, right hemiparesis, paresis of the left lower extremity, and choreoathetotic movements of the upper arms and face. Computed tomography and angiography revealed subarachnoid hemorrhage due to a dissecting aneurysm at the left A1 segment. The dissecting aneurysm was trapped surgically on the day of onset. Her neurological deficits disappeared within a month. A 39-year-old woman experienced continuous dull headache from the day before onset, and then suffered right hemiparesis. Magnetic resonance (MR) imaging revealed cerebral infarction at the left globus pallidus. Angiography and MR imaging revealed a dissecting aneurysm at the left A1 segment and occlusion of the left Heubner's artery. She received conservative treatment and her neurological findings were improved. Dissections or dissecting aneurysms involving the ACA can be classified into three types: Extension of a dissection to the ACA from the internal carotid artery, dissection at the A1 segment, and dissection at the A2-A4 segments. These types of dissection have distinct uniform clinical features.