Carotid artery stenosis is an important cause of stroke. Carotid artery stenting (CAS) provides non-inferior clinical outcome comparing to carotid endarterectomy (CEA). However, revascularization for carotid artery occlusion (CAO) remained controversial, owing to failed extracranial-to-intracranial (EC-IC) artery bypass trials, anatomical hindrance for CEA, and technical limitation for CAS. In the past 10 years, the investigators devoted in endovascular therapy for CAO and published innovative and pilot study results regarding feasibility of CAS for CAO, neurocognitive function (NCF) improvement after successful CAS for CAO, and predictors for CAS success in CAO, all in high-ranking journals. Moreover, successful CAS for CAO would lead to lower mortality and stroke rate during long-term follow-up, according to the preliminary analysis from the investigators. However, there is no prospective randomized control trial (RCT) regarding CAS in CAO patients, and in fact, most of the CAS trials excluded CAO.~The investigators, with the largest volume and experience in CAO recanalization in the world, felt obliged and responsible to propose the following RCT to evaluate endovascular revascularization for chronic CAO.~The study composed of two parts. The first part composed of prospective clinical registry for CAO. The second part compose of a prospective superiority trial, rater blinded, with 1:1 randomization to evaluate the clinical efficacy of interventional therapy for CAO. Eligible candidates for CAO revealed by CT, ultrasonography, angiography, or magnetic resonance imaging (MRI), with abnormal brain perfusion demonstrated by CT perfusion study (CTP) or MRI, will be enrolled in to study. If the participants agreed for randomization, participants will be randomized into 2 groups: the optimal medical therapy (OMT) group and the endovascular revascularization plus optimal medical therapy (ER+OMT) group. The primary end-point of the trial is the NCF improvement at 3 months and thereafter up to 12 months. The secondary endpoint includes: cumulative incidence of death and stroke within 30 days after the procedure; death or ipsilateral stroke between 31 days and 1 year; major stroke, ischemic stroke, or hemorrhagic stroke within 30 days after the procedure; major stroke, ischemic stroke, or hemorrhagic stroke between 31 days and 1 year; cognitive function measured by CANTAB; change of cerebral perfusion measured by CTP; target vessel revascularization rate; technique success rate; procedure success rate; and major procedure complication.
Revascularization for carotid artery occlusion (CAO) remained controversial, there is no prospective randomized control trial (RCT) regarding carotid artery stenting (CAS) in CAO patients. The investigators conduct a prospective study composed of clinical registry arm and RCT arm. The main purpose of the study is investigate neurocognitive function at 3 months and thereafter up to 12 months.