A Multicenter retrospective study of the COSIS technique in the treatment of chronic internal carotid artery occlusion

Objective Our study aims to introduce a novel interventional treatment strategy for the management of chronic occlusion of the internal carotid artery (CO-ICA) using a specially designed thrombectomy stent, named the Chronic artery OccluSion recanalization with Intracranial protection using Stent retriever (COSIS) technique. Methods Thirty-two patients from four centers with CO-ICA between March 2023 to September 2024 were analyzed, retrospectively. All patients were classified into four types based on the occlusion segment. Patient demographics, endovascular thrombectomy (EVT) details, recanalization rates, intraoperative complications, and follow-up outcomes were evaluated. Results All 32 patients achieved successful recanalization. Dissection occurred in four patients (12.50%). No reocclusion, perforation, or other severe intraoperative complications occurred. Thrombus was extracted in 21 patients (65.62%). The median modified Rankin Scale (mRS) score at the 3 month follow-up was 1.0 (interquartile range (IQR): 0.0–1.0). The recanalization success rate and intraoperative complications showed no significant differences among the four types of occlusions. Conclusion The COSIS technique has improved the recanalization rate and safety in different types of CO-ICA patients. Further prospective studies are needed to validate its clinical efficacy.