Proximal A1 segment aneurysm presenting with visual symptoms: A case report

Shyam Sundar Krishnan; Pulak Nigam; Girish R Menon; Madabushi Chakravarthy Vasudevan

doi:10.4103/jcvs.jcvs_15_21

CASE REPORT

Year : 2021 | Volume : 9 | Issue : 1 | Page : 56-58

Proximal A1 segment aneurysm presenting with visual symptoms: A case report

Shyam Sundar Krishnan¹, Pulak Nigam², Girish R Menon³, Madabushi Chakravarthy Vasudevan⁴
¹ Department of Neurosurgery, Kauvery Hospital; Post Graduate Institute of Neurological Surgery, Dr. A. Lakshmipathi Neurosurgical Centre, Voluntary Health Services Hospital, Chennai, Tamil Nadu, India
² Department of Neurosurgery, Medanta Multi-Specialty Hospital, Indore, Madhya Pradesh, India
³ Department of Neurosurgery, Kasturba Medical College, Manipal Academy of Higher Education, Karnataka, India
⁴ Post Graduate Institute of Neurological Surgery, Dr. A. Lakshmipathi Neurosurgical Centre, Voluntary Health Services Hospital, Chennai, Tamil Nadu, India

Date of Submission	27-Jun-2021
Date of Decision	28-Jun-2021
Date of Acceptance	18-Jul-2021
Date of Web Publication	27-Aug-2021

Correspondence Address:
Dr. Shyam Sundar Krishnan
Department of Neurosurgery, Kauvery Hospital; Post Graduate Institute of Neurological Surgery, Dr. A. Lakshmipathi Neurosurgical Centre, Voluntary Health Services Hospital, Chennai, Tamil Nadu
India

Source of Support: None, Conflict of Interest: None

DOI: 10.4103/jcvs.jcvs_15_21

Abstract

Proximal A1 segment aneurysms are technically challenging aneurysms that require careful and meticulous adherence to surgical principles for optimising the outcomes. They usually present with rupture and headache and visual symptoms are uncommon due to the optic nerve not being in proximity to the aneurysm. Important, delicate perforators arise from the segment and their preservation is the key to a good surgical outcome.

Keywords: A1 segment, aneurysms, perforators, visual symptoms

How to cite this article:
Krishnan SS, Nigam P, Menon GR, Vasudevan MC. Proximal A1 segment aneurysm presenting with visual symptoms: A case report. J Cerebrovasc Sci 2021;9:56-8

How to cite this URL:
Krishnan SS, Nigam P, Menon GR, Vasudevan MC. Proximal A1 segment aneurysm presenting with visual symptoms: A case report. J Cerebrovasc Sci [serial online] 2021 [cited 2023 Mar 28];9:56-8. Available from: http://www.jcvs.in/text.asp?2021/9/1/56/324811

Introduction

Aneurysms of the proximal segment of the anterior cerebral artery (A1 artery) are uncommon, accounting for 0.8%–3.4% of intracranial aneurysms.^{[1],[2],[3],[4]} The largest collection of A1 aneurysms published to date has been by Suzuki et al., in 1992 with 38 patients.^[3] They are challenging to treat because of their close relationship with perforators. We present report of a case of large A1 aneurysms with relatively uncommon presentation of visual symptoms along with a review of the literature on the subject.

Case Report

A 63-year-old lady presented with complaints of progressive painless diminution of vision in the left eye for the past 3 months along with occasional headache. At presentation, the patient had no perception of light (PL) in the left eye (WHO grade-5 vision loss). On examination, Glasgow Coma Score was 15. There was no anisocoria, but left pupils had a sluggish reaction to light, visual acuity was normal on right and there was no PL on left. On ophthalmoscopy, fundus on the right was normal while that on the left showed a pale disc. There were no extra-ocular movement deficits. The rest of the neurological examination was normal.

Imaging including computed tomography angiogram showed narrow-necked saccular aneurysm arising from the left A1 segment of the anterior cerebral artery (ACA), pointing anteriorly and inferiorly, measuring 12.1 mm × 10 mm with neck measuring 3.3 mm [Figure 1].

Figure 1: Computed tomography angiogram

Click here to view

She underwent left frontotemporal craniotomy, trans-sylvian approach and clipping of aneurysm with a reconstruction of ACA. She had an uneventful post-operative course and was discharged with no change in visual status in the left eye.

Discussion

Aneurysms situated on the A1 segment of the ACA are known for their rarity.^{[1],[2],[3],[4]} They have a low incidence and are rarely described in literature, with very few case series (largest being that of 38 cases by Suzuki et al.) and the rest being anecdotal case reports.^[1],[3],[5] They have a female preponderance and are more common on right but Suzuki et al., Handa et al. and Locksley have reported a conflicting higher incidence in males.^{[1],[3],[5],[6],[7]} A high incidence of multiplicity (25%–70%) is also an important feature of A1 segment aneurysms.^[3]

The most common presenting feature of A1 segment aneurysms is headache, though other features are not uncommon. Visual symptoms, per se, are uncommon in A1 segment aneurysms due to the segment not being proximate enough to the optic nerve. However, A1 segment aneurysms are very commonly associated with vascular anomalies.^[3] In fact, of the 38 cases in series by Suzuki et al., 24 had vascular anomalies. Other authors have similarly reported a large concurrence of vascular anomalies with these lesions, including A1 fenestration, accessory middle cerebral artery (MCA), azygous ACA, fenestration of anterior communicating artery (ACom), A1 elongation, MCA aplasia and interoptic course of ACA.^[3],[8] Compressive optic neuropathy has been previously reported by Arcan et al. and Fukiyama et al. among others.^[9],[10]

A number of authors have provided detailed nuances of surgical management of these aneurysms.^{[2],[11],[12],[13]} Still, others have detailed the role and nuances of endovascular treatment in the treatment of this entity.^[14],[15]

The important nuances of surgery for proximal A1 ACA aneurysms are injuries to and/or occlusion of perforating arteries, which make the surgery a technical challenge. These arteries are delicate, arise from the superior and/or posterior aspect of the A1 segment, run backwards and upwards, are commonly involved with the dome and frequently poorly visualised on pre-operative angiography and brain CT angiography.^[2],[13] Sparing the perforating arteries around the aneurysms is crucial for a satisfying neurological outcome after A1 segment aneurysm surgery. Lehecka et al. advocate operating under high magnification, adequate mobilisation of the frontal lobe, use of indocyanine green and ensuring that clip does not kink the vessels to ensure that these perforators remain uninjured.^[13]

Declaration of patient consent

The authors certify that they have obtained all appropriate patient consent forms. In the form the patient(s) has/have given his/her/their consent for his/her/their images and other clinical information to be reported in the journal. The patients understand that their names and initials will not be published and due efforts will be made to conceal their identity, but anonymity cannot be guaranteed.

Financial support and sponsorship

Nil.

Conflicts of interest

There are no conflicts of interest.

References

1.	Handa J, Nakasu Y, Matsuda M, Kyoshima K. Aneurysms of the proximal anterior cerebral artery. Surg Neurol 1984;22:486-90.
2.	Lee JM, Joo SP, Kim TS, Go EJ, Choi HY, Seo BR. Surgical management of anterior cerebral artery aneurysms of the proximal (A1) segment. World Neurosurg 2010;74:478-82.
3.	Suzuki M, Onuma T, Sakurai Y, Mizoi K, Ogawa A, Yoshimoto T. Aneurysms arising from the proximal (A1) segment of the anterior cerebral artery. A study of 38 cases. J Neurosurg 1992;76:455-8.
4.	Wanibuchi M, Kurokawa Y, Ishiguro M, Fujishige M, Inaba K. Characteristics of aneurysms arising from the horizontal portion of the anterior cerebral artery. Surg Neurol 2001;55:148-54.
5.	Wakabayashi T, Tamaki N, Yamashita H, Saya H, Suyama T, Matsumoto S. Angiographic classification of aneurysms of the horizontal segment of the anterior cerebral artery. Surg Neurol 1985;24:31-4.
6.	Locksley HB. Natural history of subarachnoid hemorrhage, intracranial aneurysms and arteriovenous malformations. Based on 6368 cases in the cooperative study. J Neurosurg 1966;25:219-39.
7.	Hacker R, Nakasu Y, Matsuda M. Data I. In: Fox JL, editor. Intracranial aneurysms. New York: Springer-Verlag; 1983. p. 19-62.
8.	Senter HJ, Miller DJ. Interoptic course of the anterior cerebral artery associated with anterior cerebral artery aneurysm. Case report. J Neurosurg 1982;56:302-4.
9.	Arcan F, Unterberg AW, Zweckberger K. Improved visual acuity after microsurgical clipping of a symptomatic anterior cerebral artery aneurysm: Case report. Br J Neurosurg 2019;33:278-80.
10.	Fukiyama Y, Oku H, Hashimoto Y, Nishikawa Y, Tonari M, Sugasawa J, et al. Complete Recovery from Blindness in Case of Compressive Optic Neuropathy due to Unruptured Anterior Cerebral Artery Aneurysm. Case Rep Ophthalmol 2017;8:157-62.
11.	Choque-Velasquez J, Hernesniemi J. Microsurgical clipping of a ruptured A1 segment aneurysm. Surg Neurol Int 2018;9:247. [Full text]
12.	Czepko R, Libionka W, Lopatka P. Characteristics and surgery of aneurysms of the proximal (A1) segment of the anterior cerebral artery. J Neurosurg Sci 2005;49:85-95.
13.	Lehecka M, Niemelä M, Hernesniemi J. Surgical management of anterior cerebral artery aneurysms of the proximal (A1) segment. World Neurosurg 2010;74:439-40.
14.	Liu P, Lv X, Li Y, Lv M. Endovascular treatment of A1 aneurysms of the anterior cerebral artery. Neurol India 2016;64:694-700. [PUBMED] [Full text]
15.	Zhang YY, Fang YB, Wu YN, Zhang Q, Li Q, Xu Y, et al. Angiographic Characteristics and Endovascular Treatment of Anterior Cerebral Artery A1 Segment Aneurysms. World Neurosurg 2017;97:551-6.