Mechanical thrombectomy after 6 hours from the symptoms onset in acute ischemic stroke in the carotid basin due to the large vessel occlusion

Abstract

Objective ‒ to assess the safety and effectiveness of mechanical thrombectomy performed no later than 6 years after the onset of symptoms in patients with ischemic stroke in the carotid basin due to occlusion of a large vessel.Materials and methods. The results of a retrospective analysis of the register of patients who received treatment at the Scientific-practical Center of endovascular neuroradiology NAMS of Ukraine in the period from 01.01.2021 to 25.12.2022 for acute ischemic stroke in the carotid basin due to occlusion of a large vessel of the brain are presented. We selected 106 patients who were functionally independent before stroke (0‒2 points on the modified Rankin Scale) and who underwent arterial puncture on the operating table for mechanical thrombectomy later 6 hours after appearance the first symptoms of stroke. The age of the patients ranged from 27 to 86 years (average age ‒ 67.3 years). There were 49 (46.2 %) men, 57 (53.8 %) women.All patients underwent multimodal neuroimaging: computed tomography (CT) of the brain, CT angiography of extracranial and intracranial cerebral arteries, or digital subtraction cerebral angiography. Quantitative assessment of initial ischemic changes in the middle cerebral artery basin was performed using the ASPECTS (Alberta Stroke Program Early CT Score). The ACG scale (American Society of Interventional and Therapeutic Neuroradiology collateral grading) was used to assess collateral blood flow.Results. The main subtype of ischemic stroke was cardioembolic ‒ 76 (71.7 %) observations. The atherothrombotic subtype occurred in 20 (18.9 %) patients. Other subtypes (cryptogenic, dissection) were diagnosed in 10 (9.4 %) cases. Occlusions in the middle cerebral artery basin were diagnosed in 69 (65.1 %) cases, tandem occlusions (internal carotid artery ‒ middle cerebral artery) were detected in 28 (26.4 %) patients. Isolated thrombosis of the internal carotid artery (I-occlusion) and T-occlusion were noted in 9 (8.5 %) observations. Well-defined collaterals (ACG score 3–4) were observed in 78 (73.6 %) patients. The group of patients with mild collateral compensation (ACG 2) accounted for 28 (26.4 %) cases. In patients within 6 to 24 hours after the onset of stroke symptoms, high-quality reperfusion (eTICI 2b-3) was achieved in 90 (84.9 %) observations. Intraoperative complications were recorded in 13 (12.3 %) cases. Among them, embolism of new arterial pools was noted in 10 (9.4 %) patients, dissection of the internal carotid artery in 1 (0.9 %) and intracranial hemorrhage due to perforation/rupture of the artery in 2 (1.9 %). Good functional results of treatment (mRS 0–2) after 90 days were observed in 54 (50.9 %) patients.Conclusions. Mechanical thrombectomy performed later than 6 hours after the onset of symptoms in acute ischemic stroke in the carotid basin due to large vessel occlusion in patients with good neuroimaging results is safe and effective.