ABSTRACT NUMBER: ESOC2026A1461 THE IMPACT OF GOOD VS EXCELLENT/COMPLETE RECANALIZATION ON MECHANICAL THROMBEDCTOMY OUTCOME

Abstract Background and aims “Good recanalization” in mechanical thrombectomy (MT) is generally defined as modified thrombolysis in cerebral infarction (mTICI) grade ≥2b. Recent data suggested the highest levels of recanalization are associated with the best outcomes. American Heart Association (AHA) guideline 2019 suggested the primary goal is to achieve TICI 2b/3. However, it is unclear if it is beneficial when multiple passes required to achieve higher levels of recanalization. This study explores the effects of reperfusion status and number of passes on functional outcome. Methods Data was obtained from the prospective MT registry from a major London comprehensive stroke centre.Baseline characteristics, MT procedures and functional outcome (modified Rankin Score (mRS)) at 90 days were recorded. Results Between January 2022 and April 2025, 278 patients were included after excluding cases of unsuccessful reperfusion (mTICI≤2a), posterior circulation stroke and missing data. Of these, 106 achieved mTICI 2b, 172 achieved 2c/3. Patients with mTICI 2c/3 had significantly lower NIHSS (National Institute of Health Stroke Scale) scores at 24hr, required fewer passes, and demonstrated better functional outcomes (mRS 0-2) (p < 0.001) compared to those with mTICI 2b, regardless collateral status or thrombolysis treatment. Patients requiring multiple passes (up to 6) still had better outcomes (45.3% in 2b vs 54.7% in 2c/3, p<0.001), without increase in haemorrhagic transformation or symptomatic intracerebral haemorrhage. Conclusions Our data showed that excellent/complete reperfusion is the key factor for better functional outcome. There was no significant effect of collateral status or thrombolysis. Multiple passes were found safe in real world practice. Conflict of interest Dr.Liqun Zhang: nothing to disclose