Predictors of Futile Recanalization After Endovascular Therapy for Acute Large Vessel Occlusive Intracranial Atherosclerosis: A Secondary Analysis of RESCUE-ICAS.

Background And Objectives: Futile recanalization in endovascular thrombectomy (EVT) occurs when recanalization is achieved but patients nevertheless experience a poor functional outcome. Variables associated with futile recanalization after endovascular therapy in intracranial atherosclerosis-related large vessel occlusion have not been previously described.

Methods: This was a secondary analysis of Registry of Emergent Large Vessel Occlusion due to Intracranial Stenosis (RESCUE-ICAS), a multicenter prospective observational cohort study conducted at 25 EVT-capable centers in North America, Europe, and Asia. RESCUE-ICAS enrolled patients who underwent EVT, after which they had residual stenosis of 50% to 99% or intraprocedural reocclusion. This particular analysis focused on patients who had "futile recanalization" after endovascular therapy, that is modified Rankin Score 3 to 6 at 90-day follow-up despite successful revascularization at procedure end (modified thrombolysis in cerebral ischemia [mTICI] 2b-3). All Included patients in the study had baseline modified Rankin Scale 0 to 2, occlusion of the intracranial internal carotid artery or M1 segment, and successful recanalization (mTICI 2b-3) after endovascular therapy.

Results: In total, 325 patients (62.8% male, mean age: 66.2 years) met the inclusion criteria. On multivariable logistic regression analysis, several variables were independently associated with futile recanalization and poor outcome, including relatively old age, higher National Institutes of Health Stroke Scale, history of type 2 diabetes, and total number of revascularization attempts. On the other hand, complete angiographic recanalization (mTICI 3 vs mTICI 2b/c) and use of an intracranial stent were inversely associated with poor outcome and were independently protective against futile recanalization.

Conclusion: Recanalization outcomes in intracranial atherosclerosis-related large vessel occlusion are inferior to thromboembolic large vessel occlusion. The broader RESCUE-ICAS cohort showed that stenting may augment end EVT thrombolysis in cerebral ischemia grading. In this analysis, which was restricted to patients experiencing good recanalization, stenting remained inversely associated with futile recanalization. Follow-up vessel imaging suggests this may be due to more durable vessel patency with stenting.