Predictors of futile recanalization in completely recanalized middle cerebral artery occlusions: multicenter study

Background Endovascular thrombectomy (EVT) improves outcomes and reduces mortality in acute ischemic stroke. However, despite achieving successful recanalization in most patients, a subset still experiences poor functional outcomes at 3 months. This failure, despite complete vessel reopening, is termed futile recanalization (FR). We investigated clinical and radiological predictors of FR in a multicenter cohort in Türkiye. Methods We retrospectively analyzed 497 consecutive patients with middle cerebral artery (M1 or M2) occlusion who underwent EVT and achieved modified Thrombolysis in Cerebral Infarction (mTICI) 3 recanalization within 6 h of symptom onset at 19 stroke centers. FR was defined as a modified Rankin Scale (mRS) score ≥4 at 3 months. Clinical and radiological parameters were recorded, and logistic regression was used to identify independent predictors of FR. Results Among 497 patients, 133 (26.7%) experienced FR despite complete recanalization. Independent predictors included older age (adjusted odds ratio aOR 1.07; 95% CI 1.03–1.10; p 0.001), longer puncture-to-recanalization time (aOR 1.03; 95% CI 1.02–1.05; p 0.001), higher admission C-reactive protein (aOR 1.01; 95% CI 1.00–1.02; p = 0.03), intracranial hemorrhage on 24-h CT (aOR 0.46; 95% CI 0.23–0.95; p = 0.04), lower collateral score (aOR 42.98; 95% CI 6.15–30.62; p 0.001), and higher 24-h NIHSS score (aOR 1.34; 95% CI 1.24–1.44; p 0.001). Conclusion Even with early and complete recanalization, elderly patients and those with poor collateral circulation remain at risk for futile recanalization. Identifying these predictors can guide patient selection, procedural planning, and post-procedural management to optimize functional outcomes.