Abstract Number: Esoc2026a1148 Direct Endovascular Versus Bridging Therapy in M2 Segment Occlusion of Middle Cerebral Artery: A MR Clean Registry Study

Abstract Background and aims This study evaluated the usage and safety of bridging intravenous thrombolysis (IVT) before endovascular treatment (EVT) for M2-segment occlusions of the middle cerebral artery (MCA), with an additional focus on transfer and mothership patients. Methods Patients from the MR CLEAN Registry (March 2014-December 2018) with MCA-M2 occlusions were included. Primary outcomes included modified Rankin Scale (mRS) scores at 90 days. Secondary outcomes included recanalization scores (TICI scores), dichotomized mRS scores (0-1, 0-2, 0-3), and symptomatic intracranial hemorrhage (sICH). Analyses were conducted using adjusted multivariable methods, incorporating inverse probability treatment weighting. Results Among 539 patients with MCA-M2 occlusions (n=377 IVT+EVT, n=162 EVT alone), IVT+EVT was significantly associated with reduced disability at 90 days (adjusted common ac OR for mRS shift:1.52; 95%CI:1.04–2.21; p=0.03). Additionally, the IVT+EVT subgroup analysis demonstrated that mothership patients benefited more (acOR for mRS shift:1.79; 95%CI:1.14-2.81; p=0.01), while no significant effect was observed in the transfer group (acOR:1.19; 95%CI:0.60-2.34; p=0.62). Functional outcomes favored IVT+EVT, though not significantly, with higher mRS 0-1 (38.9% vs. 29.7), mRS 0-2 (57.8% vs. 46.5%), and mRS 0-3 (73.2% vs. 59.4%) compared to EVT only group. Rates of recanalization success and rates of sICH were similar between both groups. Conclusions Bridging therapy may yield superior functional outcomes compared to EVT alone for patients with MCA-M2 occlusions, particularly in mothership cases. Data suggest that IVT refractory cases transferred from primary centers may benefit from additional EVT without compromising safety. Conflict of interest Drs. Doheim: nothing to disclose Dr. Knapen: nothing to disclose Prof. Staals reports compensation from Medtronic for other services. Dr Schonewille: nothing to disclose Prof. Dippel: reports funding from the Dutch Heart Foundation, Netherlands Brain Foundation, the Netherlands Organisation for Health Research and Development, Health Holland Top Sector Life Sciences grants from Health Evaluation the Netherlands to other; grants from Toegepast Wetenschappelijk Instituut voor Neuromodulatie (TWIN) Foundation to other; grants from Boehringer Ingelheim to other; grants from Dutch Heart Foundation to other; grants from Stryker Corporation to other; and grants from European Commission to other. Prof. Nogueira reports stock op¬tions in Reist/Q’Apel Medical; compensation from Shanghai Wallaby for consul¬tant services; stock holdings in Quantanosis AI; compensation from Corindus Inc for consultant services; stock holdings in Piraeus Medical; compensation from Perfuze for consultant services; compensation from Vesalio for consultant ser¬vices; compensation from Philips for consultant services; compensation from Brainomix for consultant services; compensation from RapidPulse for consultant services; stock options in viz-AI; compensation from Biogen Inc for consultant services; stock options in Viseon Inc; compensation from Anaconda Biomed for consultant services; compensation from phenox Inc for consultant services; grants from Cerenovus; compensation from NeuroVasc Technologies Inc for con¬sultant services; compensation from Synchron for data and safety monitoring ser-vices; stock options in Corindus Inc; compensation from Hybernia for consultant services; compensation from Ceretrieve for consultant services; compensation from Cerenovus for consultant services; compensation from Imperative Care for consultant services; compensation from Genentech for consultant services; com¬pensation from Medtronic USA Inc for consultant services; compensation from Imperative Care Inc for consultant services; stock options in Truvic; stock options in RapidPulse; stock holdings in Brain4Care; grants from Stryker; compensation from Prolong Pharmaceuticals for consultant services; stock options in Braino¬mix; stock options in Perfuze; stock options in Ceretrieve; compensation from Cerebrotech for consultant services; stock options in Cerebrotech; compensation from Boehringer Ingelheim for consultant services; compensation from viz-AI for consultant services; stock options in Vesalio; compensation from Corindus Vascu¬lar Robotics for consultant services; compensation from Stryker Corporation for consultant services; and compensation from Astrocyte for consultant services. Prof. van Oostenbrugge: nothing to disclose Prof. van Zwam reports grants from Johnson and Johnson International; grants from Bayer HealthCare Pharmaceuticals Inc; grants from Stryker Corporation; com¬pensation from Philips for data and safety monitoring services; and employment by Maastricht Universitair Medisch Centrum. Figure 1 - belongs to Conclusions