Mechanical thrombectomy first versus direct angioplasty or stenting for the treatment of intracranial atherosclerotic stenosis-related large vessel occlusion: protocol for a systematic review and meta-analysis

INTRODUCTION: Mechanical thrombectomy (MT) using stent retrievers or a direct aspiration first-pass technique has proven to yield better results over intravenous thrombolysis in treating acute ischaemic stroke caused by large vessel occlusion (LVO). However, the treatment of intracranial atherosclerotic stenosis-related LVO remains unclear and has been a critical problem in daily clinical practice, as it can cause a relatively high failure rate for MT. Whether direct angioplasty and/or stenting is clinically feasible and shows advantage in reducing delay to revascularisation with better functional outcome compared with MT with rescue angioplasty and/or stenting remains unclear. This study seeks to provide direct and practical clinical evidence for clinicians. METHODS AND ANALYSIS: The main databases of PubMed, the Cochrane library, Embase and Web of Science will be screened for related studies published after1 January 2015. Primary outcomes include successful recanalisation and 90-day favourable outcome. Secondary outcomes include puncture to revascularisation time, vascular complication (perforation, dissection and vasospasm), intracerebral haemorrhage, hospital-related complications and 90-day mortality. The Newcastle-Ottawa Scale will be adopted to assess risk bias of observational studies. The I(2) statistic will be used to assess heterogeneity. ETHICS AND DISSEMINATION: No primary data of patients are needed. Therefore, ethics approval is unnecessary. The results of this systematic review and meta-analysis will be published in a peer-reviewed journal. PROSPERO REGISTRATION NUMBER: CRD42021268061.