REVIEW A Direct Aspiration First Pass Technique vs Standard Endovascular Therapy for Acute Stroke: A Systematic Review and Meta-Analysis Kevin Phan, BSc(Adv), MPhil * Adam A. Dmytriw, MD, MSc ‡ Ian Teng, MD * Justin M. Moore, MD, PhD ‡ Christoph Griessenauer, MD ‡ Christopher Ogilvy, MD ‡ Ajith Thomas, MD ‡ ∗ NeuroSpine Surgery Research Group (NSURG), Prince of Wales Private Hospital, Sydney, Australia; ‡ Department of Surgery, Division of Neurosurgery, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, Massachusetts Correspondence: Kevin Phan, BSc(Adv), MPhil, NeuroSpine Clinic, Prince of Wales Private Hospital, Randwick NSW 2031, Australia. E-mail: kphan.vc@gmail.com. Received, January 24, 2017. Accepted, June 10, 2017. Copyright C  2017 by the Congress of Neurological Surgeons BACKGROUND: The direct aspiration irst pass technique (ADAPT) is a recent endovas- cular treatment for ischemic stroke due to large vessel occlusion that has been gaining popularity due to the rapidity of the technique and the potential for cost savings in comparison to standard thrombectomy methods such as stent retrievers. However, few studies have directly compared these 2. OBJECTIVE: To compare ADAPT with stent retrievers for thrombectomy via systematic review and meta-analysis. METHODS: Ovid Medline, PubMed, Cochrane Central Register of Controlled Trials, Cochrane Database of Systematic Reviews, ACP Journal Club, and Database of Abstracts of Review of Efectiveness limited to English through September 2016 were systematically searched. Eligible studies included those in which patient cohorts underwent ADAPT for acute stroke. Recanalization eiciency, clinical outcomes, and complication rates of ADAPT were compared with the current standard of endovascular thrombectomy techniques. RESULTS: Seventeen studies on ADAPT and 5 randomized controlled trials on endovas- cular therapy were included. ADAPT achieved higher rates of complete revascularisation (89.4% vs 71.7%, P < .001) but similar clinical outcomes compared to front-line endovascular therapy. Seventy-one point four percent of ADAPT cases were successfully recanalized with aspiration alone, and a trend towards reduced time from groin puncture to recanalization time was noted (44.77 vs 61.46 min, P = .088). CONCLUSION: The pooled results are comparable with recent randomized studies that demonstrate the beneit of endovascular therapy over intra-arterial medical therapy. Future direct comparative studies and randomized trials are required to conirm the beneit of the ADAPT strategy compared to standard endovascular therapy for acute ischemic stroke. KEY WORDS: Direct aspiration irst pass technique, ADAPT, Meta-analysis, Endovascular therapy, Ischemic stroke, Thrombectomy Neurosurgery 0:1–10, 2017 DOI:10.1093/neuros/nyx386 www.neurosurgery-online.com S troke remains a leading cause for morbidity and mortality 1 accounting for over 130 000 deaths in the United States and healthcare costs reaching $40 billion annually. 1 , 2 In recent randomized controlled ABBREVIATIONS: ADAPT, a direct aspiration irst pass technique; CI, conidence interval; mRS, modiied Rankin Scale; MOOSE, Meta-analysis Of Observational Studies in Epidemiology group; NIHSS, National Institute of Health Stroke Scale; sICH, symptomatic intracerebral hemorrhage; SRLA, stent retriever with local aspiration; TPA, tissue plasmogen activator trials, endovascular therapy has been shown to be superior to medical therapy for the treatment of acute ischemic stroke from large vessel occlusion. 3 - 7 Success of these trials has been attributed to the use of improved prerandom- ization imaging protocols 8 , 9 and the use of stent retrievers, which addressed the limitations of thrombectomy devices used in earlier trials. Stent retrievers can be combined with large- bore aspiration catheters, referred to as the “Solumbra” technique, where the stent retriever is removed under concurrent aspiration to minimize clot fragmentation and potential distal vessel occlusion. Although aspiration alone has been attempted for thrombectomy, NEUROSURGERY VOLUME 0 | NUMBER 0 | 2017 | 1