Mechanical Thrombectomy: Answering Unanswered

The stroke physician community witnessed a major "breakthrough" in acute stroke therapeutics when the results of the first of the many positive trials, "MR CLEAN," were published showing a significant absolute benefit in favor of mechanical thrombectomy in patients with large vessel occlusion (LVO). Thereafter, the investigators of ESCAPE, SWIFT PRIME, REVASCAT, THRACE, and PISTE concluded the same. Based on the initial studies, the American Stroke Association amended the 2013 guidelines in 2015 to include mechanical thrombectomy as the standard of care in patients with LVO presenting within six hours. In the past year, the horizon was further expanded when two major landmark trials, DAWN and DEFUSE 3, established the benefit of mechanical thrombectomy in the delayed window period in a select group of patients. It further led to the inclusion of the delayed window period treatment strategies in the 2018 guidelines. However, there are many unanswered questions in scenarios like small deficit with LVO, borderline large core, wake-up stroke (WUS), tandem occlusion, imaging of choice, conscious sedation (CS) versus general anesthesia (GA), and choice of technique. In our review, we aim to answer these questions along with a schematic representation of current techniques used in stroke thrombectomy.