Outcomes of Endovascular Thrombectomy Performed 6-24 h after Acute Stroke from Extracranial Internal Carotid Artery Occlusion

Thrombectomy has demonstrated clinical efficacy against acute ischemic stroke caused by intracranial occlusion of the internal carotid artery (ICA), even if performed 6-24 h after onset. This study investigated the outcomes of thrombectomy performed 6-24 h after stroke onset caused by extracranial ICA occlusion. Of 586 stroke patients receiving thrombectomy during the past 3 years and registered in the Tama Registry of Acute Endovascular Thrombectomy database, 24 were identified with ICA occlusion (14 extracranial and 10 intracranial), known to be well 6-24 h before presentation, and with pre-stroke modified Rankin Scale (mRS) score of 0 or 1. Clinical outcomes measured were the rate of functional independence at 90 days according to mRS score of 0-2 and 90 day mortality rate. Of patients with extracranial ICA occlusion, two received additional carotid stenting with thrombectomy. The median interval between the last time the patient was known to be well and hospital arrival was 601 (interquartile range, 476-729 min). Both the rate of functional independence at 90 days and 90 day mortality were comparable between patients with extracranial or intracranial ICA occlusion (36% vs. 40% and 7% vs. 10%, respectively). No symptomatic intracranial hemorrhages occurred within 24 h following treatment of extracranial ICA occlusion. Thrombectomy performed 6-24 h after extracranial ICA results in acceptable functional outcome. Further clinical study is warranted to better define the temporal window of thrombectomy for acceptable functional outcome in patients with extracranial ICA occlusion.