Association between collaterals, cerebral circulation time and outcome after thrombectomy of stroke

OBJECTIVE: Cerebral circulation time (CCT) and collateral score (CS) are associated with functional outcomes in acute ischemic stroke (AIS) patients after endovascular treatment (EVT), and may be related to each other. We aim to determine the relationship between CS and CCT on functional outcomes. METHODS: We retrospectively enrolled consecutive patients with anterior circulation large vessel occlusion (LVO) AIS who received EVT. CS and CCT were measured based on digital subtraction angiography (DSA). We defined CS 0–2 and 3–4 as poor and good collateral status, respectively, and used change of CCT (cCCT), which was defined as the change of stroke side CCT (sCCT) versus healthy side CCT (hCCT). Mediating analysis was used to evaluate the influence of cCCT on the association between CS and functional outcomes, and ROC curves were further used to explore the predictive ability of the interaction between cCCT and CS for functional outcomes. RESULTS: A total of 100 patients were enrolled in the final analysis. A higher cCCT (r = −0.239; p = 0.017) was associated with lower CS, and cCCT mediated the association of CS with functional outcome. Logistic regression analysis found that CS, cCCT and cCCT‐CS interactions were independently associated with functional outcome, and cCCT‐CS interaction has better predictive performance, with a higher area under curve value than CS or cCCT alone (0.79 vs. 0.75 or 0.75). INTERPRETATION: To our knowledge, this study provides the first report of the association of collateral status with cCCT, and their interaction effect on functional outcome in AIS‐LVO patients receiving EVT.