Abstract 049: Effect of the ICA Lesion Severity in Outcomes after Endovascular Treatment of Acute Tandem LVO

Introduction Tandem Lesions (TLs) pose unique challenges in the endovascular management of acute ischemic stroke.(1) The absence of anterograde blood flow in the carotid occluded segment may limit the effectiveness of endovascular interventions, resulting in delayed reperfusion or suboptimal recanalization.(2,3) Thus, the presence of unpaired blood flow through the ICA in the context of TLs is believed to exacerbate the extension of ischemic lesions. (4,5) This study compared the clinical and procedural outcomes of patients with TLs and extracranial internal carotid artery occlusion versus those with stenosis. Methods A retrospective analysis was performed on a multicenter cohort of patients with TLs who underwent endovascular treatment. The patients were categorized into two groups: those with extracranial ICA stenosis and those with occlusion. Clinical outcomes, including functional independence, hemorrhagic events, and procedural time metrics including puncture to reperfusion time were assessed. Sensitivity analyses were conducted to evaluate these differences segregating patients according to varying degrees of stenosis, and in pre‐specified subgroups. Results A total of 513 patients with TLs were included in the study. 281 (54.8%) presented with ICA occlusion, and 232 (45.2%) presented stenosis >=70% (Table 1). The comparison between the stenosis and occlusion groups revealed no significant differences in the main outcomes, including mTICI 2c‐3 (47.5% vs. 50.6%, aOR 1.07, 95% CI 0.70‐1.64, p=.751) (Figure 1), mRS 0‐2 at 90 days (43.6% vs. 48.9%, aOR 0.79, 95% CI 0.52‐1.20, p=.271), sICH rates (4.7% vs. 5.6%, aOR 0.72, 95% CI 0.31‐1.71, p=.458), and puncture to reperfusion time (58 [40‐80.5] vs. 52.5 [35.2‐80], ratio 1.04, 95% CI 0.88‐1.23, p=.64). Similar analyses performed comparing different degrees of stenosis and occlusion, and in patients treated with the antegrade approach only, did not show significant differences either. Conclusion Our findings indicate that although more severe degrees of stenosis or occlusion of the ICA prolong the time from puncture to reperfusion, no significant differences in clinical outcomes exist. The clinical implications of these findings need to be further evaluated to fully comprehend the specific needs of patients affected by TLs.