Department of Interventional Neurology, Beijing Tiantan Hospital, Capital Medical University

Background The management of patients with symptomatic nonacute intracranial artery occlusion (sNA-ICAO), which is a special subset with high morbidity and a high probability of recurrent serious ischemic events despite standard medical therapy (SMT), has been clinically challenging. Some small-sample clinical studies have also discussed endovascular recanalization for sNA-ICAO; however, there is currently a lack of evidence from multicenter, prospective, large-sample cohort trials. The aim of our present study was to evaluate the technical feasibility and safety of endovascular recanalization for sNA-ICAO.

Methods and analysis: Our group is currently undertaking a multisite, nonrandomized cohort, prospective registry study enrolling consecutive patients presenting with sNA-ICAO at 15 centers in China between May 1, 2020, and April 30, 2023. A cohort of patients who received SMT and a cohort of similar patients who received ER plus SMT were constructed and followed up for 2 years. The primary outcome is the composite of stroke/TIA within 2 years following enrollment and stroke/TIA ipsilateral to the target vessel. The secondary efficacy outcome includes the following two parts: 1) the incidence of stroke/TIA ipsilateral to the target vessel within 30 days and 90 days in both groups; 2) the all-cause mortality, mRS score, NIHSS score and cognitive function at 30 days, 90 days, 8 months, 12 months and 24 months for both groups, including the MRI, CTA/MRA, CTP or MRP results in patients with internal carotid artery or middle cerebral artery occlusion as well as CTA in patients with basilar or vertebral artery occlusion at 90 days, 12 months and 24 months. Descriptive statistics and linear/logistic multiple regression models will be generated. Clinical relevance will be measured as relative risk reduction, absolute risk reduction and the number needed to treat.

Ethics and dissemination This study protocol was reviewed and approved primarily by Beijing Tiantan Hospital, the Capital Medical University Medical Ethics Committee, and the institutional review boards of all partner sites. The study is being externally monitored, and the results will be published in open-access peer-reviewed scientific journals and presented to academic and policy stakeholders.