Neuroendovascular management of emergent large vessel occlusion: update on the technical aspects and standards of practice by the Standards and Guidelines Committee of the Society of NeuroInterventional Surgery

Acute ischemic stroke (AIS) is the fifth leading cause of death, and remains the leading cause of disability in the USA.1 There are an estimated 680 000 new strokes per year in the USA, with a mortality rate of 53–94%, and with an even greater morbidity.2 It is estimated that 3–22% of these patients are candidates for endovascular therapy.3–6 In addition to baseline stroke severity, emergent large vessel occlusion (ELVO) has been shown to be an independent predictor of poor outcome at 6 months.3 4 While intravenous recombinant tissue plasminogen activator (IV r-tPA) has proven efficacious predominantly for small cerebral vessel occlusions, endovascular therapies, including stent retriever based, aspiration based mechanical thrombectomy techniques, and intra-arterial administration of thrombolytic agents, have been shown to achieve higher rates of recanalization in patients with ELVO.7–10 The purpose of this document is to provide an update and critical assessment of technical aspects of the mechanical thrombectomy procedure. This document was prepared by the Standards and Guidelines Committee of the Society of NeuroInterventional Surgery (SNIS), a multidisciplinary society representing the leaders in the field of endovascular therapy for cerebrovascular disease. A review of the English language literature published between January 1998 and March 2016 was conducted using search terms that included: ‘stroke,’ ‘ischemic stroke,’ ‘large vessel occlusion,’ ‘thrombectomy,’ ‘mechanical thrombectomy,’ ‘neurointerventional,’ ‘tPA,’ and ‘technique.’ Additionally, we incorporated already existing guidelines published by the American Heart Association (AHA) and the SNIS.11–15 The strength of the evidence supporting each recommendation was summarized using a scale previously described by the AHA guideline panels, and by the University of Oxford, Centre for Evidence Based Medicine .13 15–18 Much of our current practice in mechanical thrombectomy derives from recent randomized controlled trials (RCTs) which provide a foundation for treatment goals. The online supplementary tables 1-3 provide details of these thrombectomy trials, …