Abstract WP39: Radiographic Classification of ICA Occlusions Predicts Clinical Fluctuation and Post-Stenting Hemorrhage Risk

Abstract

Introduction: The optimal treatment strategy for symptomatic extra-cranial internal carotid artery (ICA) occlusion remains unknown. A radiographic classification of ICA occlusions has been proposed to help predict technical feasibility and the risk of complications with revascularization. The classification includes 4 main types (A-D) based on the morphology of the ICA stump (A having a tapered stump, B having a non-tapered stump, C and D having no stump) as well as the presence of reconstitution of flow in the intracranial ICA (C having reconstitution of the ICA within the cavernous and/or petrous segment and D having no reconstitution). In this study, we assess the predictive value of this classification scheme in understanding clinical phenotype and post-stenting complications. Methods: A retrospective review of a prospectively maintained database was conducted of clinical and radiological data from patients undergoing attempted angioplasty and stenting of complete symptomatic cervical ICA occlusion without tandem intracranial occlusion. Results: Seventy-two patients were included in the study, with a mean age of 63 years and 36% female gender. Classification type was as follows: 36% (type A), 25% (type B), 32% (type C) and 7% (type D). Revascularization was successful in 66/72 (92%) of patients. Clinical fluctuation prior to revascularization was most frequent in type A occlusions (p=0.02) and least frequent in type B occlusion (p=0.02). Only 8% of patients had peri-procedural intracerebral hemorrhage and the highest frequency occurred in group D (p=0.05). In a multivariate analysis, lower age, lower pre-treatment NIH Stroke Scale and favorable Alberta Stroke Program Early CT Score were predictors of higher modified Rankin Scale at 3 months (p=0.025, 0.004, 0.049, respectively). Conclusions: Radiographic classification of ICA occlusions can help classify patient phenotypes and potentially predict the technical safety of angioplasty and stenting. Prospective studies are warranted to confirm these findings.