To investigate the Endovascular Treatment difference between Chinese city and country hospital.

Endovascular Treatment for AIS in Chinese Municipal and County Hospitals： A "Real World" Study-ETERNITY Registry is an academic , independent, pragmatic , prospective , multicenter , observational registry study . Patients with acute ischemic stroke caused by anterior circulation intracranial large vessel occlusion and receiving EVT were included. Patients were divided into primary stroke center (county hospital) and senior stroke center (city hospital) groups. Acute ischemic stroke (AIS) workflow, EVT procedural details and clinical outcome were compared in two groups. The aim of the study was to explore the EVT difference in Chinese city and county hospital.

Inclusion Criteria:

(1) age ≥18 years; (2) diagnosis of AIS caused by imaging-confirmed intracranial LVO, including isolated cervical internal carotid artery or tandem occlusion, intracranial internal carotid artery, middle cerebral artery (M1/M2), anterior cerebral artery (A1/A2); (3) initiation of any type of EVT, including mechanical thrombectomy, emergent angioplasty via balloon or/and stent; (4).Onset-to-presentation time with 24 hours; (5).Patients whose onset-to-presentation time surpass 6 hours should had CTP and fulfill with DAWN[6] or DEFUSE's[7] criteria.

Exclusion Criteria:

(1) Without follow up outcome; (2) posterior circulation stroke;(3)no evidence of LVO on angiogram.

Patients with acute ischemic stroke caused by anterior circulation intracranial large vessel occlusion and receiving EVT were included.