ABSTRACT NUMBER: ESOC2026A2315 BEYOND ANGIOGRAPHIC SUCCESS: FLAT-PANEL CT DISTAL OCCLUSION TRACKER SIGN IDENTIFIES INCOMPLETE REPERFUSION AFTER THROMBECTOMY

Abstract Background and aims Early neurological deterioration (END) may occur despite angiographically successful mechanical thrombectomy (MT). Flat-panel detector CT (FPDCT) allows immediate post-procedural detection of distal embolization and reperfusion-related injury. We investigated whether FPDCT markers identify patients at increased risk of END beyond conventional angiographic grading. Methods In this prospective multicentre observational study, consecutive patients with anterior circulation stroke treated with MT at two comprehensive stroke centres were included. Post-procedural FPDCT was used to assess the presence of the distal occlusion tracker (DOT) sign. The primary outcome was END. Secondary outcomes included functional outcome, 24-hour ASPECTS and haemorrhagic complications. Associations between the DOT sign and clinical-radiological variables, including Thrombolysis in Cerebral Infarction recanalization score (TICI), were evaluated through univariate and multivariate logistic regression. Results Among 374 patients, the DOT sign was present in 31%.DOT-positive patients had higher rates of END compared with DOT-negative patients (25.0%vs12.8%, P = 0.003).The DOT sign was associated with lower rates of successful reperfusion (TICI≥2b:79.3%vs91.1%,P < 0.001) and higher prevalence of cortical hyperattenuation on FPDCT.In multivariate analysis, the DOT sign independently predicted END (adjusted OR2.07,95%,CI1.03–4.15), together with cardioembolic etiology, baseline NIHSS, lower FPDCT ASPECTS and unsuccessful reperfusion. DOT-based adjudication led to reclassification of approximately half of angiographic TICI3 cases to lower reperfusion grades. Conclusions The DOT sign is a practical post- thrombectomy imaging marker helping in the prediction of END. Integrating the DOT sign assessment may help in the stratification of tissues at risk and risk of END, adding to the selection of patients for adjunctive intra-arterial medications. Conflict of interest Valentina Tudisco: nothing to disclose; Michele Romoli: nothing to disclose; Francesca Giannini: nothing to disclose; Davide Vicari: nothing to disclose; Federica N. Sepe: nothing to disclose; Fabrizio Giammello: nothing to disclose; Marco Longoni: nothing to disclose; Antonio Toscano: nothing to disclose; Maria Ruggiero: nothing to disclose.