Thrombectomy for Anterior Circulation Stroke in a Witnessed Late Time Window Versus Early Time Window

Thrombectomy is the standard treatment for anterior circulation stroke due to large vessel occlusions in a late time window (6 to 24 hours) for patients selected based on perfusion imaging. Most patients treated in late time window studies presented as unwitnessed or wake-up strokes. Whether patients presenting with unwitnessed stroke have an actual time window greater than 6 hours is unclear. The aim of this study was to assess the outcomes of thrombectomy in the treatment of patients presenting with anterior circulation large vessel stroke in an actual late time window of more than 6 hours.

This single-center registry of thrombectomy in the treatment of stroke caused by anterior circulation large vessel occlusions (LVOs) included 430 patients treated between 2011 and 2019. Patients were divided into 2 groups: an early time window (≤ 6 hours) group and a late time window group (> 6 hours).

Outcomes of the early and the late time window groups, respectively, were recanalization of 86.8% vs 82.7% (P = .29), symptomatic intracranial hemorrhage of 8.2% vs 5.7% (P = .40), good clinical outcome of 45.4% vs 41.3% (P = .46), and mortality of 20.2% vs 25% (P = .30) at 3 months.

Thrombectomy for anterior circulation large vessel occlusions after 6 hours of symptoms onset seems to be as safe and effective as the standard thrombectomy within 6 hours from symptoms onset, even without perfusion analysis. Randomized trials are needed to confirm these findings.