ABSTRACT NUMBER: ESOC2026A862 MECHANICAL THROMBECTOMY BEYOND STRICT GUIDELINES: A 5-YEAR SINGLE-CENTER EXPERIENCE

Abstract Background and aims Mechanical thrombectomy (MT) has demonstrated significant benefits in patients meeting strict ESO guidelines criteria: mRS ≤1, large vessel occlusion (internal carotid artery, M1 segment of the middle cerebral artery or basilar artery), NIHSS ≥6, ASPECTS ≥6, and a door-to-needle time ≤6 hours or ≤24 hours with a favourable mismatch on multimodal CT. Based on preliminary results from 2023, this study expands the analysis to a longer time period. The aim was to compare long-term functional outcomes between patients treated within protocol indications and those treated off-protocol. Methods A retrospective study was conducted on patients undergoing MT at a tertiary hospital between 2020 and 2024. Patients were classified as treated within or outside strict protocol criteria. Functional outcomes were evaluated using the mRS and NIHSS at 3, 6 and 12 months. Results Two hundred fifty-seven patients were studied (n=128 women, 50.8%; mean age 75.3 years SD 12.9). Off- protocol cases included patients with mRS>1 (n=61, 36.6%), ASPECTS <6 (n=6, 3.8%) and occlusions in the M2 (n=83, 49.7%) and M3 (n=4, 2.4%) segments of the middle cerebral artery, anterior cerebral artery (11, 6.6%), posterior cerebral artery (n=9, 5.4%) and vertebral artery (n=5, 3%). At 12 months, mean NIHSS scores were 1.8 (SD 3.7) versus 1.8 (SD 3.6) and mRS scores 1.9 (SD 2) versus 2.6 (SD 2.2), with no statistically significant differences. Conclusions In this expanded cohort, long-term functional outcomes were comparable between patients treated within and outside strict guideline criteria, supporting the potential benefit of MT in selected patients beyond current indications. Conflict of interest nothing to disclose