Flow diversion for incidental ophthalmic segment internal carotid artery aneurysm in a young adult following malignant ischemic stroke

Naba Kumar Roy1*, Gowdham Pannirselvam2

1Nursing Officer – ICU, Kauvery Hospital, Marathahalli, Bangalore

2Senior Nurse Educator, Kauvery Hospital, Marathahalli, Bangalore

*Correspondence

Abstract

Intracranial aneurysms involving the ophthalmic segment of the internal carotid artery constitute a distinct subgroup of anterior circulation aneurysms [2,5]. The increasing use of advanced neuroimaging has led to a rise in the incidental detection of small unruptured aneurysms [1,2]. Management decisions become particularly challenging in young patients with a history of major cerebrovascular events [3,9]. Flow diversion has emerged as a transformative endovascular strategy for the treatment of complex intracranial aneurysms by reconstructing the parent vessel and promoting gradual aneurysm occlusion [11-14]..We report the case of a young adult male with a previous left internal carotid artery ischemic stroke requiring mechanical thrombectomy, decompressive craniectomy, and subsequent cranioplasty. During neurovascular evaluation, a small incidental aneurysm arising from the ophthalmic segment of the right internal carotid artery was identified. The aneurysm was successfully treated using a flow-diverting stent. Postoperative recovery was uneventful, and the patient was discharged on dual antiplatelet therapy and rehabilitation. This report discusses the anatomical considerations, pathophysiology, diagnostic evaluation, treatment options, and current evidence supporting flow diversion for ophthalmic artery aneurysms [11-17].

Keywords: Internal carotid artery aneurysm, ophthalmic aneurysm, flow diverter, ischemic stroke, endovascular neurosurgery, intracranial aneurysm.

Introduction

Intracranial aneurysms affect approximately 2–5% of the general population and represent localized dilatations of cerebral arteries resulting from weakening of the vessel wall [1]. Although many aneurysms remain asymptomatic throughout life, rupture can result in subarachnoid haemorrhage, a condition associated with significant morbidity and mortality [2,3]. The ophthalmic segment of the internal carotid artery is a common location for aneurysm formation due to unique hemodynamic stresses generated at vascular bends and branch points [5-8]. The advent of high-resolution computed tomography angiography, magnetic resonance angiography, and digital subtraction angiography has significantly improved the detection of incidental aneurysms [2,9]. Management of small unruptured aneurysms remains controversial because treatment-related risks must be balanced against the lifetime risk of rupture [3,9].. Flow-diversion technology has transformed aneurysm management by reconstructing the parent artery rather than directly targeting the aneurysm sac [11-14]. This technique is particularly advantageous for aneurysms located along the ophthalmic segment of the internal carotid artery, where conventional clipping or coiling may be technically challenging [15,16]. This report presents a young adult with a complex neurovascular history who underwent successful flow-diverter placement for an incidental ophthalmic artery aneurysm.

Anatomy of the Internal Carotid Artery and Ophthalmic Segment

The internal carotid artery (ICA) is one of the principal arteries supplying the brain. It originates from the common carotid artery and ascends through the neck without giving branches until it enters the skull through the carotid canal [5,6].

The ICA is traditionally divided into several segments:

  • Cervical segment
  • Petrous segment
  • Lacerum segment
  • Cavernous segment
  • Clinoid segment
  • Ophthalmic (supraglenoid) segment
  • Communicating segment

Image Source: Binh Q. Tran et al, Springer Nature Link, Volume 18; 2019

The ophthalmic segment extends from the distal dural ring to the origin of the posterior communicating artery [5,6]. The ophthalmic artery usually arises from this segment and supplies the orbit, retina, optic nerve, and surrounding structures [6]. Because of abrupt directional changes and continuous pulsatile blood flow, this region experiences considerable wall shear stress, predisposing it to aneurysm formation [7,8].

Physiology and Hemodynamics

The cerebral circulation requires continuous blood flow to maintain oxygen and nutrient delivery. Cerebral autoregulation allows relatively stable perfusion despite fluctuations in systemic blood pressure [6]. Normal blood flow through the ICA is laminar. However, vascular curves and branch points create areas of altered wall shear stress. Over time, these hemodynamic forces contribute to endothelial dysfunction and degeneration of the arterial media [7,8].

Factors influencing aneurysm formation include:

  • Hypertension
  • Smoking
  • Genetic predisposition
  • Connective tissue disorders
  • Abnormal vascular geometry
  • Hemodynamic stress

The ophthalmic segment is especially vulnerable because blood flow changes direction as the artery curves toward its terminal bifurcation [7,8].

Case Presentation

A 26-year-old male with a prior history of major ischemic stroke presented for evaluation and management of an incidentally detected intracranial aneurysm. Several months before admission, the patient experienced sudden onset weakness involving the right upper and lower extremities accompanied by slurring of speech. Neuroimaging revealed a left internal carotid artery territory ischemic stroke. Emergency endovascular thrombectomy was performed. Due to malignant cerebral edema, decompressive craniectomy was subsequently required. Following neurological stabilization, cranioplasty was performed. During follow-up neurovascular evaluation, computed tomography angiography and digital subtraction angiography identified a small aneurysm arising from the ophthalmic segment of the right internal carotid artery. The aneurysm measured approximately 3.5 × 3.1 × 3.0 mm and projected inferomedially. At admission, the patient was neurologically stable. Residual right-sided motor deficits were present, characterized by mild weakness and a hemiplegic gait. Higher mental functions were preserved, and the patient remained conscious, alert, and oriented. After multidisciplinary discussion, endovascular treatment using flow-diversion technology was selected.

Investigations

Computed tomography of the brain demonstrated postoperative changes related to previous decompressive craniectomy and cranioplasty. Encephalomalacia changes involving the left front temporoparietal region were observed, consistent with prior ischemic injury. Computed tomography angiography identified a small aneurysmal outpouching originating from the ophthalmic segment of the right internal carotid artery.

Digital subtraction angiography confirmed:

  • Ophthalmic ICA aneurysm
  • Dimensions approximately 3.5 × 3.1 × 3.0 mm
  • Inferomedial projection
  • Favourable anatomy for flow-diversion treatment

Digital subtraction angiography remains the gold standard because of its superior spatial and temporal resolution [9].

Treatment and Procedure

The patient underwent flow-diverter placement under general anaesthesia.

Image Source: Endovascular treatment of arterial aneurysm; DR. Karthikeyan Damodhara

A flow diverter is a densely braided metallic stent placed across the aneurysm neck. The device redirects blood along the parent artery while reducing inflow into the aneurysm [11-14].

The treatment promotes:

  • Progressive thrombosis within the aneurysm
  • Endothelial growth across the neck
  • Parent vessel reconstruction
  • Long-term aneurysm exclusion

The procedure was completed successfully without intraoperative complications.

Alternative Treatment Modalities

Historically, ophthalmic aneurysms have been treated using microsurgical clipping or endovascular coiling [10,18,19]. Microsurgical Clipping involves craniotomy and placement of a titanium clip across the aneurysm neck. Advantages include immediate exclusion of aneurysm and durable long-term results. Disadvantages include brain retraction, optic nerve risk, and higher morbidity [10].

Endovascular Coiling involves packing the aneurysm sac with coils. Advantages include minimally invasive approach and shorter recovery. Disadvantages include recurrence risk and retreatment requirement [18,19].Flow Diversion provides parent vessel reconstruction, high occlusion rates, and suitability for complex aneurysms [11-17].

Discussion

The management of small incidental aneurysms remains controversial [3,9]. Although aneurysms smaller than 5 mm generally possess a lower rupture risk, patient age significantly influences treatment decisions [3,9]..Flow diversion has emerged as a preferred treatment for ICA aneurysms because it addresses the underlying vascular pathology rather than simply filling the aneurysm sac. Multiple studies demonstrate occlusion rates exceeding 80–90% at long-term follow-up [11-14,20].

Ophthalmic artery aneurysms are particularly suited to flow diversion because the parent artery can be preserved while maintaining collateral circulation [15,16].

Reason why it is flow diversion not a Endovascular coiling

In the present case, flow diversion was selected because the aneurysm was in the ophthalmic segment of the internal carotid artery, a region where microsurgical exposure can be technically demanding and may carry a risk of optic nerve manipulation or visual complications. Although endovascular coiling is a less invasive alternative, small ophthalmic ICA aneurysms may have a higher likelihood of incomplete occlusion or recurrence depending on aneurysm morphology. Flow diversion offers reconstruction of the parent vessel while promoting gradual thrombosis of the aneurysm, thereby treating the underlying vascular pathology rather than simply occluding the aneurysm sac. In this young patient with a long-life expectancy and a previous history of major ischemic stroke requiring thrombectomy and decompressive craniectomy, a minimally invasive approach with high long-term occlusion rates and reduced need for retreatment was considered advantageous. Furthermore, the aneurysm anatomy was favourable for flow-diverter deployment, making flow diversion the preferred treatment strategy.

Outcome and Follow-Up

Recovery was uneventful. The patient remained stable without new neurological deficits. Dual antiplatelet therapy was continued to prevent in-stent thrombosis [11-14]. Rehabilitation was advised for prior stroke-related deficits. Long-term imaging surveillance is required to confirm aneurysm occlusion and stent patency [11-14].

Conclusion

This case illustrates successful management of an incidental ophthalmic segment internal carotid artery aneurysm in a young patient with prior ischemic stroke. Flow diversion provided effective and durable treatment while avoiding morbidity associated with open microsurgery [11-16].. Careful selection, imaging, and multidisciplinary decision-making are essential for optimal outcomes [9,11]. Flow diversion represents a promising long-term solution for selected ophthalmic ICA aneurysms in young patients [15-17].

References

  • Vlak MHM, Algra A, Brandenburg R, Rinkel GJE. Prevalence of unruptured intracranial aneurysms, with emphasis on sex, age, comorbidity, country, and time period: a systematic review and meta-analysis. Lancet Neurol. 2011;10(7):626-636.
  • Wiebers DO, Whisnant JP, Huston J III, Meissner I, Brown RD Jr, Piepgras DG, et al. Unruptured intracranial aneurysms: natural history, clinical outcome, and risks of surgical and endovascular treatment. Lancet. 2003;362(9378):103-110.
  • Etminan N, Rinkel GJE. Unruptured intracranial aneurysms: development, rupture and preventive management. Nat Rev Neurol. 2016;12(12):699-713.
  • Lawton MT, Vates GE. Subarachnoid hemorrhage. N Engl J Med. 2017;377(3):257-266.
  • Bouthillier A, van Loveren HR, Keller JT. Segments of the internal carotid artery: a new classification. Neurosurgery. 1996;38(3):425-433.
  • Standring S, editor. Gray’s Anatomy: The Anatomical Basis of Clinical Practice. 42nd ed. London: Elsevier; 2020.
  • Meng H, Tutino VM, Xiang J, Siddiqui A. High WSS or low WSS? Complex interactions of hemodynamics with intracranial aneurysm initiation, growth, and rupture. Am J Neuroradiol. 2014;35(7):1254-1262.
  • Cebral JR, Mut F, Weir J, Putman C. Quantitative characterization of the hemodynamic environment in ruptured and unruptured brain aneurysms. Am J Neuroradiol. 2011;32(1):145-151.
  • Thompson BG, Brown RD Jr, Amin-Hanjani S, Broderick JP, Cockroft KM, Connolly ES Jr, et al. Guidelines for the management of patients with unruptured intracranial aneurysms. Stroke. 2015;46(8):2368-2400.
  • Day AL. Aneurysms of the ophthalmic segment: a clinical and anatomical analysis. J Neurosurg. 1990;72(5):677-691.
  • Becske T, Kallmes DF, Saatci I, McDougall CG, Szikora I, Lanzino G, et al. Pipeline for uncoilable or failed aneurysms: results from the PUFS trial. Neurosurgery. 2013;73(1):113-124.
  • Briganti F, Napoli M, Leone G, Marseglia M, Mariniello G, Caranci F, et al. Treatment of intracranial aneurysms by flow diverter devices: long-term results from a single center. Eur J Radiol. 2014;83(9):1683-1690.
  • Kallmes DF, Brinjikji W, Cekirge S, Fiorella D, Hanel RA, Jabbour P, et al. Safety and efficacy of the Pipeline Embolization Device for treatment of intracranial aneurysms: a pooled analysis. J Neurosurg. 2017;127(4):775-780.
  • Martínez-Galdámez M, Lamin SM, Lagios KG, Liebig T, Ciceri EF, Chapot R, et al. Periprocedural safety and technical outcomes of the Pipeline Flex embolization device. J Neurointerv Surg. 2017;9(1):38-44.
  • Chalouhi N, Tjoumakaris S, Gonzalez LF, Dumont AS, Starke RM, Hasan D, et al. Treatment of ophthalmic segment aneurysms with flow diversion: clinical and angiographic outcomes. Neurosurgery. 2014;74(3):E356-E362.
  • Rouchaud A, Leclerc O, Benayoun Y, Saleme S, Camilleri Y, D’Argento F, et al. Visual outcomes with flow-diverter stents covering the ophthalmic artery. Am J Neuroradiol. 2015;36(2):330-336.
  • Brinjikji W, Murad MH, Lanzino G, Cloft HJ, Kallmes DF. Endovascular treatment of intracranial aneurysms with flow diverters: a meta-analysis. Stroke. 2013;44(2):442-447.
  • Molyneux AJ, Kerr RSC, Yu LM, Clarke M, Sneade M, Yarnold JA, et al. International Subarachnoid Aneurysm Trial (ISAT) of neurosurgical clipping versus endovascular coiling. Lancet. 2005;366(9488):809-817.
  • Pierot L, Spelle L, Vitry F; ATENA Investigators. Immediate clinical outcome of patients harboring unruptured intracranial aneurysms treated by endovascular approach. Stroke. 2008;39(9):2497-2504.
  • Adeeb N, Griessenauer CJ, Foreman PM, Moore JM, Motiei-Langroudi R, Chua MHJ, et al. Use of flow diverters in treatment of intracranial aneurysms: a systematic review and meta-analysis. World Neurosurg. 2017;106:507-520.

Nightingale Journals

Kauvery Hospital
Find Doctor
Book Appointment