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|LETTER TO EDITOR
|Year : 2014 | Volume
| Issue : 1 | Page : 80-82
Large unruptured proximal (A1) anterior cerebral artery aneurysm with aplasia of the contralateral A1
Ananthan Raghothaman1, Lekha Pandit2
1 Department of Neurosurgery, K S Hegde Medical Academy, Mangalore, Karnataka, India
2 Department of Neurology, K S Hegde Medical Academy, Mangalore, Karnataka, India
|Date of Submission||09-Dec-2013|
|Date of Decision||19-Dec-2013|
|Date of Acceptance||26-Jan-2014|
|Date of Web Publication||7-Mar-2014|
Department of Neurosurgery, K S Hegde Medical Academy, Mangalore, Karnataka
Source of Support: None, Conflict of Interest: None
|How to cite this article:|
Raghothaman A, Pandit L. Large unruptured proximal (A1) anterior cerebral artery aneurysm with aplasia of the contralateral A1. Neurol India 2014;62:80-2
Aneurysms from proximal A1 horizontal segment of anterior cerebral artery (ACA) are rare and may be associated with vascular anomalies of the circle of Willis. We report one such patient with a large un-ruptured proximal A1 aneurysm with absent contra-lateral A1.
A 58-year-old male patient presented with giddiness and headache of 1 week duration. Brain computed tomography (CT) scan carried out at other facility showed a left supra-sellar cistern hyperdense well-circumscribed lesion [Figure 1]a. This was followed by cerebral four-vessel angiography which revealed left A1 segment unruptured aneurysm [Figure 1]b. On admission at our facility neurological examination was essentially normal. CT-angiography [Figure 1]c carried out at our facility revealed large A1 segment aneurysm measuring 11.7 mm × 12.8 mm × 11.5 mm and neck measuring 5.7 mm, arising from left A1 segment with absent right A1. Both A2 were being supplied by left A1 on which the aneurysm was present.
|Figure 1: (a) Computed tomography brain showing suprasellar hyperdense lesion (b) four-vessel angiogram showing A1 large aneurysm (c) computed tomography angiogram showing the large A1 aneurysm with aplasia of contralateral A1 (d) post-operative computed tomography brain showing the sugita clip in situ (e) post-operative computed tomography angiogram showing aneurysm obliteration with clip|
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As the aneurysm was a large un-ruptured and on the sole ACA (A1), the risks of surgery were explained to the patient and then taken up for clipping of aneurysm. A left pterional craniotomy was carried out, sylvian fissure dissected and internal carotid artery bifurcation was identified and traced forward to the aneurysm neck. Temporary clipping of A1 proximal to aneurysm was used a few times to dissect the aneurysm fundus and neck. Gyrus rectus was resected to expose the fundus and prevent traction on the aneurismal fundus. No branches were seen near the neck or fundus. Neck of the aneurysm was clipped using an 8 mm Sugita clip. Aneurysm sac was aspirated by needle puncture and collapsed and then shrunken with bipolar coagulation. No refilling of the sac was seen.
Post-operatively patient was managed in neurological intensive care unit and electively ventilated for 48 h. Hyponatremia was corrected and patient recovered well with no deficits. Repeat CT scan [Figure 1]d showed small hematoma at craniotomy site beneath the bone flap which resolved in the CT scan carried out 1 week later. Patient was discharged on day-20 and on follow-up at 1 month was doing well. Check CT angiography [Figure 1]e in the follow-up showed complete obliteration of the aneurysm with no refilling and clip in situ.
Aneurysms of any size involving A1 segments are rare and form <1% of all intracranial aneurysms.  Usually A1 aneurysms are small, fragile and tend to rupture.  Giant aneurysm of A1 have also been reported in the literature. , Un-ruptured aneurysms of A1 are to be clipped as they have propensity to rupture.  These aneurysms are also associated with vascular anomalies and sometimes are part of multiple aneurysms occurrences.  Our patient had a large unruptured proximal A1 aneurysm with absent contralateral A1. We suggest that due this vascular anomaly the flow in the ipsilateral A1 would have been high and this flow dynamics could have led to the formation of the large aneurysm.
A1 aneurysms are either clipped or coiled based on their anatomy and patient preferences. When treating such A1 aneurysm one should keep in mind the anatomy of the aneurysm, associated vascular anomalies and patient preferences. After explaining all the options available, our patient elected to undergo clipping. Post-surgery patient had an uneventful recovery and post-operative check CT angiogram showed obliteration of the aneurysm with good flow in both the distal A2.
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