Angiographic classification of nonacute carotid artery occlusion to predict the feasibility and clinical outcomes of endovascular recanalization

OBJECTIVE Endovascular treatment of nonacute symptomatic carotid artery occlusion (NASCAO) remains a technical challenge. The heterogeneity of a successful recanalization rate has limited its clinical efficacy. The aim of this study was to introduce an angiographic classification to determine the feasibility and clinical outcomes of endovascular recanalization for NASCAO patients. METHODS The authors analyzed consecutive patients who underwent endovascular treatment of NASCAO in a nationwide prospective registry. Patients were divided into 4 occlusion groups according to a novel classification based on distal carotid reconstitution level, distal retrograde stump morphology, and proximal stump morphology. The rate of technical success, procedural complications, 30-day postoperative stroke risk, and long-term clinical outcomes were analyzed. RESULTS Of 425 patients enrolled in the final analysis, the overall successful recanalization rate was 55.8% (237/425), and the 30-day postoperative major stroke rate was 3.8% (16/425). The rate of technical success was 80.7% (92/114) for type A, 80.7% (88/109) for type B, 40.9% (47/115) for type C, and 11.5% (10/87) for type D occlusions (p CONCLUSIONS In NASCAO patients with recanalization attempts, type A/B occlusion was associated with a higher success rate and a lower long-term risk of ischemic cerebrovascular event. The NASCAO classification may assist in the selection of appropriate patients for endovascular treatment.