Symptomatic Retinal Artery Occlusion after Angioplasty and Stenting of the Carotid Artery: Incidence and Related Risk Factors

Objective: Retinal artery occlusion (RAO) is rarely seen as a complication in patients undergoing carotid artery stenting (CAS); hence, its characteristics have not been documented in detail. This study aimed to investigate the incidence of this complication and the related risk factors, focusing on differences in ophthalmic artery (OA) supply (whether by the external or internal carotid artery [ECA or ICA]) prior to CAS procedures. Materials and Methods: We retrospectively examined 342 patients who underwent CAS for severe and/or symptomatic carotid artery stenosis between January 2009 and December 2017. Cumulative medical records and radiologic data were assessed. RAO was confirmed by photography and fluorescent angiography of the fundus, which were performed by an ophthalmologist. In all patients, distal filter systems of various types were applied as cerebral protection devices (CPDs) during procedures. Univariate and multivariate analyses were conducted to identify the risk factors for RAO after CAS. Results: Symptomatic RAO was observed in six patients (1.8%), of which five (6.8%) were ECA-dominant group members (n = 74). In a binary logistic regression analysis, OA supply by the ECA (odds ratio [OR], 9.705; 95% confidence interval [CI], 1.519-62.017; p = 0.016) and older age (OR, 1.159; 95% CI, 1.005-1.336; p = 0.041) were identified as significant risk factors in patients with RAO after CAS. ECA-supplied OA was also associated with the severity of ipsilateral ICA stenosis (p = 0.001) and ulcerative plaque (p = 0.021). Conclusion: In procedures performed using ICA distal filtering CPD systems, RAO as a complication of CAS (performed for severe stenosis) showed a relationship to ECA-supplied OA. For older patients, simultaneous use of ICA-ECA CPDs might help prevent such complications.