Mechanical Thrombectomy for Anterior versus Posterior Circulation Large Vessel Occlusion Stroke with Emphasis on Posterior Circulation Outcomes

Purpose: Although there is class I evidence for mechanical thrombectomy (MT) for anterior circulation large vessel occlusion (LVO) stroke, no high-class evidence exists for the posterior circulation. Here, we sought to compare clinical features of anterior versus posterior LVO as well as predictors of a posterior LVO MT outcome. Methods: Patients with acute ischemic stroke who underwent MT for anterior and posterior LVO stroke between February 2016 and August 2020 from 2 comprehensive stroke centers were reviewed. Anterior and posterior LVO strokes were compared. In addition, predictors for a favorable outcome (modified Rankin scale [mRS] 0–3), death (mRS 6), and futile revascularization (mRS 4–6 despite TICI 2b/3 revascularization) for posterior LVO were analyzed. Results: Collectively, 813 LVO thrombectomy cases were analyzed, and 77 of 813 cases (9.5%) were located in the posterior circulation. Although favorable 90-day functional outcome rates did not differ between anterior and posterior LVO (P = 0.093), death was significantly more frequent among posterior LVO cases (P = 0.013). In the posterior LVO subgroup, a primary aspiration technique and successful revascularization TICI 2b/3 irrespective of time to the intervention were independently associated with achieving a favorable outcome. Primary aspiration was identified to inversely associate with futile revascularization. Conclusion: Anterior and posterior circulation MT patients have distinct clinical profiles. The use of primary aspiration appears fundamental for beneficial outcomes in posterior circulation MT.