Perspective of optical coherence tomography angiography in visual outcome prognosis in patients after aneurysm stenting of the ophthalmic segment of the internal carotid artery. Pilot study

Background. In microinvasive surgery of aneurysms of the ophthalmic segment of the internal carotid artery (AOS-ICA), flow-diverting stents are often used, which overlap the area of the ophthalmic artery origin. This type of treatment may be accompanied by visual acuity decrease in the intraas well as in the early and late postoperative period.

Aim – to evaluate ocular hemodynamics indices in patients with AOS-ICA before and after the ophthalmic segment of the internal carotid artery stenting.

Materials and methods. The study group consisted of 17 patients (16 women and 1 man), age median being 48.5 years (from 23 to 68), admitted to the Polenov Neurosurgical Institute during the period from April, 2022, through November, 2024. Inclusion criteria: age more than 18 years, unilateral AOS-ICA of no less than 4 mm diameter, absence of CT-signs of visual pathway compression and of ophthalmic complaints, absence of retinal and optic nerve pathologic condition, and sufficient transparency of the optical media. To visualize the aneurysm, the reconstruction of 3D images obtained from rotational angiography was used. Angiographic images were obtained in anteroposterior, lateral, and working projections before and immediately after treatment. The treatment consisted in stenting of the ICA ophthalmic segment by a flow-diverting stent DERIVO 2 (Acandis Pforzheim, Germany). The ophthalmic examination was carried out before and after surgery and included standard diagnostic methods and OCT, OCTA of the macular area and the optic disc area. Additionally, a calibrometry of arteries and veins with estimation of their average diameter (ADA, ADV).

Results. After stenting, in 4 out of 17 patients, on the AOS-ICA side, within the period from 3 to 14 days, visual disturbances were noted in form of multiple episodes of transitory monocular blindness, their duration being from 30 seconds to several hours. In patients with such complications, at comparison with the contralateral eye indices, on the involved side, a reduced perfusion density in all plexuses was noted (by 1.0–4.2 % in the superficial, by 1.3–7.2 % in the deep, and in the radial peripapillary – by 2.1–3.0 %). On the involved side, in comparison to the contralateral eye, there was also a significant ADA decrease (79.4 μm versus 85.3 μm, P<.001), ADV however had no significant differences (102.6 μm versus104.23 μm, Р=.580).

Conclusions. The carried-out pilot study showed that preoperative detection of local defects of retinal and optic disc capillary perfusion, as well as asymmetry of peripapillary arterioles in AOS-ICA, could be markers of collateral blood flow insufficiency manifesting itself by transitory episodes of monocular blindness after stenting. 

1. Beatty RA. Splitting of the optic nerve by a carotid-ophthalmic artery aneurysm. Case report J. Neurosurg. 1986:65(4);560-562. Doi: 10.3171/jns.1986.65.4.0560.

2. Michishita S, Ishibashi T, Yuki I, Urashima M, Karagiozov K, Kodama T, Kan I, Nishimura K, Kato N, Ikemura A, Murayama Y. Visual complications after coil embolization of internal carotid artery aneurysms at the ophthalmic segment. Interv Neuroradiol. 2021;27(5):622-630. Doi: 10.1177/1591019921996886.

3. Kachhara R, Nair S, Nigam P. Ophthalmic segment aneurysms: surgical treatment and outcomes. J Neurosci Rural Pract. 2021;12(4);635-641. Doi: 10.1055/s-0041-1734002.

4. Krayenbühl H. Treatment of carotid-cavernous fistula consisting of a one-stage operation by muscle embolization of the fistulous carotid segment. In book: Microvascular Surgery. Stuttgart, Thieme, 1967:151-167.

5. Day AL. Aneurysms of the ophthalmic segment. A clinical and anatomical analysis. J Neurosurg. 1990;72(5):677- 691. Doi: 10.3171/jns.1990.72.5.0677.

6. Heller RS, Lawlor CM, Hedges TR 3rd, Bababekov YJ, Safain MG, Malek AM. Neuro-ophthalmic effects of stenting across the ophthalmic artery origin in the treatment of intracranial aneurysms. J Neurosurg. 2014;121(1):18-23. Doi: 10.3171/2014.3.JNS131493.

7. Griessenauer CJ, Ogilvy CS, Foreman PM, Chua MH, Harrigan MR, Stapleton CJ et al. Pipeline embolization device for small paraophthalmic artery aneurysms with an emphasis on the anatomical relationship of ophthalmic artery origin and aneurysm. J Neurosurg. 2016;125(6):1352-1359. Doi: 10.3171/2015.12.JNS152499.

8. Sherif C, Gruber A, Dorfer C, Bavinzski G, Standhardt H, Knosp E. Ruptured carotid artery aneurysms of the ophthalmic (C6) segment: clinical and angiographic long term follow-up of a multidisciplinary management strategy. J Neurol Neurosurg Psychiatry. 2009;80(11):1261-1267. Doi: 10.1136/jnnp.2008.170860.

9. Fiorella D, Woo HH, Albuquerque FC et al. Definitive reconstruction of circumferential, fusiform intracranial aneurysms with the Pipeline embolization device. Neurosurgery. 2008;62(5):1115-1120; discussion 1120-1121. Doi: 10.1227/01.NEU.0000313128.12325.14.

10. De Jesus O, Sekhar LN, Riedel CJ. Clinoid and paraclinoid aneurysms: surgical anatomy, operative techniques, and outcome. Surg Neurol. 1999;51:477-487. Doi: 10.1016/S0090-3019(98)00137-2.

11. Yu JW, Shim YS, Lee JW et al. Vision outcomes of endovascular treatment for unruptured ophthalmic artery aneurysms. World Neurosurg. 2018;116:e1223-e1229. Doi: 10.1016/j.wneu.2018.05.238.

12. Molyneux AJ, Birks J, Clarke A, Sneade M, Kerr RS. The durability of endovascular coiling versus neurosurgical clipping of ruptured cerebral aneurysms: 18 year follow-up of the UK cohort of the International Subarachnoid Aneurysm Trial (ISAT). Lancet. 2015;385(9969):691-697. Doi: 10.1016/S0140-6736(14)60975-2.

13. Pierot L, Cognard C, Ricolfi F, Anxionnat R; CLARITY Investigators. Immediate anatomic results after the endovascular treatment of ruptured intracranial aneurysms: analysis in the CLARITY series. AJNR Am J Neuroradiol. 2010;31(5):907- 911. Doi: 10.3174/ajnr.A1954.

14. Kim B, Jeon P, Kim K et al. Endovascular treatment of unruptured ophthalmic artery aneurysms: clinical usefulness of the balloon occlusion test in predicting vision outcomes after coil embolization. J Neurointerv Surg. 2016;8(7):696- 701. Doi: 10.1136/neurintsurg-2015-011800.

15. Rouchaud A, Leclerc O, Benayoun Y et al. Visual outcomes with flow-diverter stents covering the ophthalmic artery for treatment of internal carotid artery aneurysms. AJNR Am J Neuroradiol. 2015;36(2):330-336. Doi: 10.3174/ajnr.A4129