Mechanical thrombectomy for acute large vessel occlusion stroke beyond 24 h

Multiple trials have shown that mechanical thrombectomy (MT) is superior to medical therapy. However, no robust evidence is available regarding MT beyond 24 h. In this study, we aimed to determine the safety and efficacy of endovascular stroke therapy in this late window.

We conducted a retrospective study of prospectively collected data of patients who met extended window trial criteria, but underwent MT beyond 24 h. Safety and efficacy outcomes included symptomatic intracerebral hemorrhage (sICH), procedural complications, number of passes, successful recanalization (mTICI 2b - 3), delta (Δ) NIHSS (baseline-discharge), and favorable outcomes (mRS 0-2 at 90 days).

A total of 39 patients were included with a median age of 69 years (IQR 61.5, 73.5); 54% were females. Hypertension was present in 76% of patients; 23% were smokers. Half of the patients had M1 occlusion (48.7%). Median preprocedural NIHSS was 11 (IQR 7.0, 19.5). Successful revascularization was achieved in 87%; median number of passes was 2 (IQR 1.0, 3.0). Median ΔNIHSS was 3.0 (IQR -1.5, 8.0). Favorable outcome was achieved in 49% (95% CI: 34%-64%), and 95% were free of complications. A total of 3 patients (7.7%) had sICH. In an exploratory analysis, posterior circulation occlusion was associated with higher mRS at 90 days (OR: 14.7, p = 0.016). Favorable discharge facility was associated with lower mRS at 90 days (OR: 0.11, p = 0.004).

Our study showed comparable clinical outcomes of MT beyond 24 h compared to MT trials within 24 h in patients with favorable imaging profile, especially in anterior circulation occlusions.