Optional or optimal? off-label stenting for intracranial atherosclerotic stenosis: A scoping review

Background Intracranial atherosclerotic stenosis is a major cause of ischemic stroke. In addition to the Wingspan stent system, several self-expanding stents have been used off-label to treat intracranial atherosclerotic stenosis lesions. The purpose of this review is to assess the existing data on the off-label use of self-expanding stents in intracranial atherosclerotic stenosis, to highlight methodological limitations in current study designs, and thus providing strategies and precautions for clinical practice. Methods The PubMed, EMBASE, and the Cochrane Library databases were systematically searched for relevant articles published up to April 2022. In addition to the meta analysis of Enterprise, Neuroform EZ and closed cell stent respectively, we used a narrative synthesis to summarize and discuss the appropriate strategies and precautions for the use of each stent. Results We identified 17 studies (1091 patients with 1124 lesions) reporting 6 types of off-label self-expanding stents. The most common endpoints reported were incidence of short-term complications (range: 0-15.8%, median: 3.8%), long-term complications (range: 0-12.0%, median: 0%). Potential risks include infeasibility of stenting hard lesions or tortuous vessels, stent migration, and in-stent thrombosis. Less is known about the conditions that are appropriate for an optimal stent (e.g., open-cell, close-cell, hybrid cell). There was considerable heterogeneity across studies with regards to study populations and study designs. Conclusions The potential risks and benefits should be carefully considered when using off-label stents for intracranial atherosclerotic stenosis, particularly given the current evidence power. As a potential option for the Wingspan stent, based on device's approval only, a tailored approach with lesion-specific devices could be beneficial in certain patients.