ABSTRACT NUMBER: ESOC2026A1996 DIFFERENCES OF INTERNAL CEREBRAL VEIN DRAINAGE BEFORE REPERFUSION THERAPIES PREDICTS CEREBRAL OEDEMA AND POOR OUTCOMES IN PATIENTS WITH ANTERIOR CIRCULATION ACUTE ISCHEMIC STROKE

Abstract Background and aims Reperfusion therapies for acute ischemic stroke (AIS) may be complicated by cerebral edema (CED) and hemorrhagic transformation (HT), leading to poor outcomes. Identifying predictors of these complications before treatment is therefore crucial. Since arterial collateral circulation improves tissue survival and outcomes, we hypothesized that asymmetries in internal cerebral veins (ICVs) drainage on multiphasic CT angiography (mCTA) could serve as an adjunctive predictor of reperfusion-related complications. Methods We retrospectively analyzed consecutive AIS patients with M1 occlusion treated with reperfusion therapies between 2022-2024. ICV drainage asymmetry was assessed on mCTA using symmetrical regions of interest on the affected and contralateral ICVs across all phases. Primary outcomes included 90-day modified Rankin Scale (mRS), development of CED or HT, and final infarct volume. Unfavorable outcome was defined as mRS 4–6. HT and CED were evaluated on CT scans at 24–48 hours according to ECASS and SITS-MOST criteria. Results A total of 201 patients were included (mean age 73±14 years; 50.2% female). Mean admission NIHSS was 16±7; 47.8% underwent MT alone and 52.2% combined MT and IT. After treatment, 18.9% developed CED, 21.4% HT, and 5.0% symptomatic intracerebral hemorrhage. Good functional outcome (mRS 0–2) occurred in 44.3%. On univariate analysis, ICV drainage type was significantly associated with HT, CED, and unfavorable functional outcome, together with baseline ASPECTS, perfusion parameters, and procedural factors. Conclusions Assessment of ICV venous drainage on mCTA represents a valuable and simple imaging marker for predicting reperfusion-related complications and poor functional outcomes in AIS patients with M1 occlusion. Conflict of interest nothing to disclose for all authors