Abstract TP301: Chronic internal carotid artery occlusion research and exploration in Cerebral Recanalization Center (CIRCLE-CRC): Innovative Insights and Clinical Outcomes

Background: CIAO (chronic internal carotid artery occlusion), characterized by the persistent occlusion of the internal carotid artery, is associated with an elevated risk of recurrent stroke and other vascular events. While previous studies have explored various clinical features of CIAO, there remains a gap in large-scale, multi-center data examining the full spectrum of risk factors and predictors of adverse outcomes. Understanding these factors is crucial for refining patient management strategies and improving long-term prognosis for individuals affected by CIAO. Purpose: This retrospective study introduces our multi-center database of patients with chronic CIAO. It aims to evaluate the risk factors associated with adverse clinical outcomes, thereby contributing to a better understanding of the disease's progression and its potential impact on patient management. Results: During a median follow-up of 42.5 months (IQR 30.2–55.4 months), the study included 633 patients with chronic CIAO, with a median age of 62 years (IQR [56-68] years). Of these, 550(86.9%) were male. A significant proportion of the cohort had a history of smoking (61.3%) and drinking (45%), while 435(68.7%) had a history of hypertension. The most recent ischemic event occurred 2 months prior(IQR [1.0-4.5]). 119 patients(23.0%) experienced Transient Ischemic Attack(TIA) and 363 patients(70.2%) had stroke as the most recent symptom. 227 patients(47.4%) had a prior infarction in the responsible vascular area, and 177(37.8%) demonstrated distal wall collapse in High-Resolution Magnetic Resonance Imaging(HR-MRI). Specifically, 46 patients(7.3%) underwent endovascular intervention alone, 233 patients(36.8%) underwent carotid endarterectomy alone, and 354 patients(55.9%) underwent hybrid surgery (endarterectomy plus endovascular intervention). Successful reperfusion rate was 88.9%. The study also explored long-term outcomes, reporting the incidence of stroke, TIA, and death as 12.7%(42/332), 3.6%(12/332), and 3%(10/332). Distal wall collapse in HR-MRI was a predictive factor for long-term symptomatic cerebral infarction (P=<0.001; OR=2.484; 95%CI:1.479-4.172). Conclusion: This multi-center database provides a valuable resource for understanding the characteristics and outcomes of patients with chronic CIAO. These findings underscore the need for personalized treatment strategies and closer monitoring of high-risk individuals in this patient population.