Objective: The American Heart Association/American Stroke Association guidelines recommend that patients should receive mechanical thrombectomy if the Alberta Stroke Program Early Computed Tomography Score (ASPECTS) is ≧6. However, its benefits are uncertain if the ASPECTS is ＜6. This study aimed to identify the outcomes of mechanical thrombectomy in patients with ASPECTS ＜6.
Methods: Thirty-nine patients with acute ischemic stroke with diffusion weighted imaging (DWI)-ASPECTS ≦5, with internal carotid artery or middle cerebral artery segment 1 (M1) occlusion were treated with mechanical thrombectomy between May 2014 and April 2018. We retrospectively compared patients with a good outcome [modified Rankin Scale (mRS): 0-2] and those with a poor outcome (mRS 3-6) at 3 months.
Results: The good-outcome group comprised 16 patients (41%) and the poor outcome group comprised 23 patients (59%) at 3 months. There were no significant differences in the baseline characteristics [age, sex, occluded artery, National Institutes of Health Stroke Scale score and DWI-ASPECTS] between the two groups. The onset to recanalization time was shorter in the good-outcome group (192 versus 210 minutes, p=0.0083). The mean DWI-ASPECTS of the good-outcome group did not change between arrival and post thrombectomy (5 versus 4, p=0.24), but the mean DWI-ASPECTS of the poor-outcome group worsened (5 versus 2, p=0.0014) between hospitalization and after thrombectomy.
Conclusions: The outcome of mechanical thrombectomy could be good even in patients with low DWI-ASPECTS and a magnetic resonance angiography-DWI mismatch.