Visual outcomes with flow-diverter stents covering the ophthalmic artery for treatment of internal carotid artery aneurysms

Abstract

Background and purpose: Flow-diverting stents can be used to treat intracranial aneurysms that are not amenable to treatment with coils. We analyzed ophthalmic consequences due to coverage of the origin of the ophthalmic artery by flow-diverting stents for the treatment of internal carotid artery aneurysms.

Materials and methods: From April 2009 to April 2013, the clinical and angiographic outcomes of all 28 patients treated for aneurysms with flow-diverting stents covering the origin of the ophthalmic artery were prospectively collected. The origin of the ophthalmic artery in relation to the target aneurysm was classified by using a 4-type classification. A complete ophthalmic examination was performed by a single ophthalmologist 48 hours before and 1 week after covering the ophthalmic artery.

Results: Ophthalmic artery patency was normal at the end of endovascular treatment in 24/28 cases (85.7%). With extensive ophthalmic examinations, 11 patients (39.3%) showed new ophthalmic complications. Patients with the ophthalmic artery originating from the aneurysm sac were at high risk for retinal emboli (4/5, 80%). Patients with the ophthalmic artery originating from the inner curve of the carotid siphon were at high risk for optic nerve ischemic atrophy (3/4, 75%).

Conclusions: This prospective study shows that covering the ophthalmic artery with a flow-diverting stent is not without potential complications. Ophthalmic complications can occur but are often not diagnosed. The anatomic disposition of the ophthalmic artery in relation to the carotid siphon and aneurysm should be clearly understood because some configurations have a higher risk. When not required, covering of the ophthalmic artery by flow-diverting stents should be avoided.

Fig 1.

Classification according to the anatomy of the origin of the covered ophthalmic artery: the ophthalmic artery aneurysm classification. A, Type A: ophthalmic artery originating from the aneurysm sac. B, Type B: ophthalmic artery originating from the neck of the aneurysm. C, Type C: ophthalmic artery originating in the inner curve of the carotid siphon. D, Type D: ophthalmic artery not involved in the aneurysm but covered by the Pipeline Embolization Device.

Fig 2.

Illustrative case for type A. A, Left internal carotid artery angiograms: a and b, 3D angiograms with 2 carotid ophthalmic aneurysms with the ophthalmic artery originating from the aneurysm. c–e, Angiogram 3 months after flow-diverting stent implantation showing patency of the ophthalmic artery with a remnant of the upper aneurysm (arrow in e). B, Left eye funduscopic examination showing hyperattenuated embolic material in a retinal artery of the inferior retina (arrow). C, Explicative schema: a, The flow in the ophthalmic artery is turbulent due to the aneurysm. b, After placement of an FDS across the aneurysm neck, the turbulent flow is modified and may induce partial thrombosis of the aneurysm. c, The outflow channel that constitutes the ophthalmic artery may be the route for ophthalmic thromboemboli and subsequent retinal infarcts.

Fig 3.

Illustrative case of type C. A, Right internal carotid artery 3D angiogram showing a carotid ophthalmic aneurysm with the ophthalmic artery originating from the inner curve of the ICA. B, Three-month ophthalmic examination: a, Right eye fluorescein retinal angiography showing an arterial flow defect in the upper part of the retina (arrow). b and c, Visual field assessment showing a large central scotoma in the right eye. d and e, Mean retinal thickness in the central foveal area, measured by using optical coherence tomography, proved right optic nerve atrophy (right eye, 55.03 μm; left eye, 100.65 μm).