Computational Fluid Dynamics Analysis of Carotid-Ophthalmic Aneurysms with Concomitant Ophthalmic Artery Infundibulum...

Although previous studies have reported cases of coexistence of carotid-ophthalmic aneurysm and ophthalmic artery (OA) infundibulum, the hemodynamic characteristics of this complicated structure and its damaging effects on vision remain to be elucidated. The aim of the present study was to analyze this artery structure using computational fluid dynamics (CFD) techniques.

We have presented the case of a patient with a diagnosis of carotid-ophthalmic aneurysm, who had been experiencing blurred vision. A transient analysis was performed to investigate the blood flowing in the parent artery. Hemodynamic parameters such as streamline, wall shear stress (WSS), oscillatory shear index (OSI), and relative residence time were obtained.

When the inlet velocity of the parent artery was at the second peak, the flow rate and intensity of the vortex reached their maximum. In the aneurysm neck, a region of high time-averaged WSS (TAWSS) and a region of low TAWSS with a high OSI coexisted. In addition, a relaxation area was found. In the aneurysm dome, the minimum TAWSS was 2.5 Pa, the maximum OSI was 0.48, and the 2 regions did not overlap. In the OA infundibulum, the maximum OSI and relative residence time were 0.47 and 39.2, respectively; the minimum TAWSS was 0.59 Pa.

We detected aneurysm regions that were susceptible to further expansion and assessed the rupture risk of each region. The relaxation area could promote aneurysm progression. In addition, the location of the vortex shear force center varied with time. Finally, double vortex streamlines influenced the blood supply through the OA, impairing the vision. Infundibulum might promote thrombus formation and, hence, retard OA blood flow.