Association of cerebral collateral cascade with early neurological deterioration after endovascular thrombectomy in patients with acute ischemic stroke.

Background: Early neurological deterioration (END) often leads to poor long-term outcomes in patients with acute ischemic stroke (AIS). This study aimed to investigate the association between comprehensive collateral circulation status and END. Methods: We retrospectively analyzed data from patients with AIS treated between January 2020 and December 2022. END was defined as an increase of ≥4 points in the National Institutes of Health Stroke Scale (NIHSS) at 24 hours after endovascular thrombectomy (EVT) compared with baseline. Collateral circulation was assessed according to the cerebral collateral cascade (CCC), a composite framework integrating arterial collateral assessed by the Tan score, tissue-level collateral quantified by the hypoperfusion intensity ratio (HIR), and venous outflow (VO) evaluated by the Cortical Vein Opacification Score (COVES). Based on these assessments, patients were classified into three groups: CCC- group (poor arterial, venous, and tissue-level collaterals), CCC+ group (good arterial, venous, and tissue-level collaterals), and CCC Results: A total of 293 patients were included, of whom 64 (21.8%) developed END. The incidence of END was highest in the CCC- group (46.8%), followed by the CCC Conclusions: CCC could effectively predict END after thrombectomy and outperformed clinical variables and single collateral measures in this regard. Its predictive value remained significant even in unexplained END, supporting its potential in early risk assessment.