Endovascular Recanalization of Symptomatic Nonacute Intracranial Internal Carotid Artery Occlusion: Proposal of a New Angiographic Classification

BACKGROUND AND PURPOSE: The optimal treatment for symptomatic nonacute intracranial ICA occlusion is uncertain, and endovascular recanalization remains a technical challenge. Our purpose was to report multicenter clinical results of endovascular recanalization for medically refractory, nonacute, intracranial ICA occlusion and to propose a new angiographic classification to explore which subgroups of patients are most amenable to this treatment. MATERIALS AND METHODS: From January 2015 to December 2019, thirty-six consecutive patients who underwent endovascular recanalization for refractory, nonacute, atherosclerotic intracranial ICA occlusion at 3 stroke centers were analyzed retrospectively. The patients were divided into 3 types according to an angiographic classification. Rates of technical success, periprocedural complications, and any stroke or death within 30 days along with follow-up results were evaluated. RESULTS: The overall technical success rate was 80.6% (29/36), and the rate of any stroke or death within 30 days was 16.7% (6/36). The recanalization success rate gradually decreased from type I to type III in the 3 classification groups (92.9%, 81.3%, and 50%, P = .038), and the opposite was true of the perioperative complication rates (7.1%, 18.8%, and 50%, P = .038). Type I lesions showed favorable recanalization effects, 92.9% technical success rates, and 7.1% perioperative complications. CONCLUSIONS: Endovascular recanalization for nonacute atherosclerotic intracranial ICA occlusion is technically feasible, especially in patients with type I lesions, and could offer an alternative option for patients with recurrent ischemic symptoms despite aggressive medical therapy. The angiographic classification proposed is conducive to the selection of suitable patients and difficulty in grading.