Impact of basal ganglia damage after successful endovascular recanalization for acute ischemic stroke involving lenticulostriate arteries

OBJECTIVE Regional ischemic vulnerability of the brain reportedly differs between the cortex and basal ganglia and has been poorly assessed in the setting of endovascular mechanical thrombectomy. This study was conducted to determine the fate of an ischemic basal ganglia and its contribution to the clinical outcome after successful endovascular recanalization for acute ischemic stroke with large vessel occlusion involving the lenticulostriate arteries. METHODS Clinical and radiological findings were retrospectively analyzed in consecutive patients with acute ischemic stroke characterized by large vessel occlusion involving the lenticulostriate arteries. Mechanical thrombectomy was performed in all patients using a stent retriever. The fate of ischemic basal ganglia based on location (lentiform nucleus, caudate nucleus, and internal capsule) and insular cortex was assessed according to the Alberta Stroke Programme Early CT Score (ASPECTS). RESULTS Of 170 patients with large intracranial vessel occlusion who achieved successful endovascular recanalization, defined as a thrombolysis in cerebral infarction grade of ≥ 2B, involvement of the lenticulostriate arteries was seen in 55 patients (internal carotid artery, n = 35; proximal middle cerebral artery, n = 20). Preoperative infarction was detected in the lentiform nucleus (66.7%), internal capsule (11.1%), and caudate nucleus (33.3%), all of which showed secondary advancement despite successful recanalization (85.4%, 27.3%, and 54.5%, respectively; p < 0.05). Lenticulostriate arteries with a lateral proximal and/or medial proximal origin significantly affected the development of mature infarction in the lentiform nucleus. Postoperative hemorrhagic transformation was detected in 25 of 55 patients, mostly in the lentiform nucleus. Involvement of insular ribbon infarction was significantly high in patients with hemorrhagic transformation in the basal ganglia. Age, initial National Institutes of Health Stroke Scale (NIHSS) score, initial ASPECTS, postoperative ASPECTS, postoperative infarction in the insular ribbon, and lesions in the middle cerebral artery area (M 1 –M 6 ) were significantly different between patients with good and poor modified Rankin Scale scores. Interestingly, no differences were detected in postoperative infarction or hemorrhagic transformation in the basal ganglia. Multivariate analysis showed that only age (p = 0.02, OR 0.88) and the initial NIHSS score (p = 0.01, OR 0.86) independently affected favorable clinical outcomes. CONCLUSIONS The basal ganglia are vulnerable and readily develop secondary infarction and hemorrhagic transformation despite successful recanalization. However, this does not have a significant impact on the clinical outcome of acute ischemic stroke with large vessel occlusion involving the lenticulostriate arteries.