Risk score for futile recanalization: integrating cerebral circulation time and collateral cascade

Impaired microvascular reperfusion despite successful recanalization may contribute to futile recanalization (FR) following thrombectomy. By combining cerebral circulation time (CCT) and cerebral collateral cascade (CCC) to evaluate hemodynamic and microcirculatory disturbances, we aim to develop and validate a new comprehensive prognostic model to predict FR after thrombectomy.

This retrospective cohort study involved a thorough analysis of perfusion and collateral status (CCT and CCC) in consecutive acute ischemic stroke (AIS) patients presented with large vessel occlusion who underwent thrombectomy and achieved successful recanalization between January 2022 and December 2024. Independent predictors of FR were obtained from the least absolute shrinkage and selection operator regression and multivariable logistic regression. A nomogram model was constructed, and its discrimination and calibration were assessed.

This study included 182 patients, of whom 73 (40.11%) suffered from FR. Feature importance identified ischemic core volume (OR 1.01, 95% CI 1.00-1.03, p = 0.017), CCC (OR 3.09, 95% CI 1.24-8.40, p = 0.020), relative change of CCT (OR 5.87, 95% CI 1.45-26.36, p = 0.016), and neutrophil-to-lymphocyte ratio (OR 2.73, 95% CI 1.30-5.96, p = 0.009) as the most important predictors. The final model was discriminatory for predicting 3-month FR (area under the receiver operating characteristic curve 0.733, 95% CI 0.659-0.806) and had good calibration (Brier 0.201, 95% CI 0.175-0.226; Hosmer-Lemeshow test, p = 0.770). Decision curve analysis indicated a higher mean net benefit at lower treatment thresholds (up to 0.90).

The new prognostic model provides a valuable tool for predicting FR, thereby improving individualized stroke management.