Futile Reperfusion After Rescue Stenting for Occlusive Intracranial Atherosclerosis: A Secondary Analysis of RESCUE-ICAS

Introduction: “Futile reperfusion” in mechanical thrombectomy (MT) occurs when recanalization is achieved and patients nevertheless experience a poor functional outcome. We hypothesized that ICA occlusion and increasing attempts might be associated with poor functional outcomes in patients who underwent rescue stenting for intracranial atherosclerosis (ICAS)-related occlusions.

Methods: This was a secondary analysis of RESCUE-ICAS, a multicenter prospective observational cohort study conducted at 25 thrombectomy-capable centers in North America, Europe, and Asia. RESCUE-ICAS enrolled patients who underwent MT, after which they had residual stenosis of 50-99% or intraprocedural re-occlusion. This particular analysis focused on patients who had “futile reperfusion” after rescue stenting, that is modified Rankin Score 3-6 at 90-day follow-up in spite of good revascularization at procedure end (TICI 2b-3). Included patients had baseline mRS 0-2 and occlusion of the intracranial ICA or M1 segment.

Results: In the RESCUE-ICAS cohort, there were 199 patents treated with MT+stenting, of which 181 (90.9%) achieved mTICI≥2b. An additional 63 patients were excluded for having posterior circulation (51) or anterior circulation medium vessel (12) occlusions, leaving 118 for analysis. Among these, the rate of poor functional outcome at 3 months was 52.5% (62/118). On random effects logistic regression, the following variables were significantly associated with poor functional outcome: age quartile 3 (69-78 years vs. < 59, OR 11.98, p< 0.001), age quartile 4 (≥79 years vs. < 59, OR 10.99, p=0.002), and Black race/ethnicity vs. white (OR 5.28, p=0.004). Complete recanalization (TICI3 vs. 2b/2c) was inversely associated poor functional outcome (OR 0.21, p=0.021). The location of occlusion (ICA vs. M1) and the number of passes before stent placement were not associated with dichotomized mRS at 90-day follow-up.

Conclusion : Although patients with ICAS often have excellent collateral circulation, incomplete revascularization following rescue stenting was associated with futile reperfusion. An association between Black race/ethnicity and futile reperfusion after salvage stenting is also novel and warrants further investigation.