Endovascular Thrombectomy in Acute-Onset Ischemic Stroke – beyond the Standard Time Windows: A Case Report and a Review of the Literature

Endovascular thrombectomy following an acute ischemic stroke can lead to improved functional outcome when performed early. Current guidelines suggest treatment within 6 h after symptom onset. Recent studies including the DEFUSE-3 and DAWN trials demonstrate that some patients may benefit from thrombectomy up to 16 and 24 h after symptom onset, respectively. We present a case of delayed thrombectomy in a 43-year-old man with acute dysarthria, left-sided weakness, and visual neglect. Initial MRI/A demonstrated a small completed stroke and a thrombus in the right middle cerebral artery. Thirty-seven hours after symptom onset, his weakness acutely worsened. A repeat MRI revealed an unchanged core infarct volume and a cerebral angiogram suggested an abrupt occlusion of the right distal M1. Thrombectomy was performed with complete reperfusion and the patient's strength recovered following the procedure. We compared our clinical reasoning with the DEFUSE-3 and DAWN study criteria, and conclude that there is a subset of patients that may safely benefit from thrombectomy in later time windows beyond the trial criteria, especially in the setting of clinical examination of imaging mismatch.