Endovascular thrombectomy for isolated posterior cerebral artery occlusion: distinct clinical presentation patterns and neurological outcomes in P1 versus P2 segments

Background Endovascular thrombectomy (EVT) for isolated posterior cerebral artery (PCA) occlusion remains incompletely characterized, particularly regarding segment-specific presentation and outcomes. We aimed to compare clinical profiles, procedural results, and early neurological and imaging outcomes between P1 and P2 PCA occlusions treated with EVT. Methods We retrospectively analyzed EVT-treated patients with acute ischemic stroke at a tertiary center from 2018–2025 ( n = 1,166). Thirty-nine patients with isolated PCA occlusion were included in the final analysis (P1 n = 27; P2 n = 12). Successful reperfusion was defined as mTICI 2b–3. Baseline and 24-h CT were assessed for detecting ischemic change using posterior circulation ASPECTS (PC-ASPECTS). Neurological deficits were analyzed using NIHSS total scores and clinical domain profiles. Results Patients with P1 occlusion presented with higher admission stroke severity than those with P2 occlusion NIHSS 12 (7–23) vs. 7 (4–9) and more frequent motor/sensory deficits and facial palsy, whereas P2 occlusions commonly presented with visual dysfunction. Successful reperfusion was achieved in 72% overall (P1 78% vs. P2 58%). Median 24-h PC-ASPECTS was similar 8 (IQR 8–9). Despite successful reperfusion in P1 occlusion, neurological impairment frequently persisted at discharge, particularly in motor, sensory, vigilance, and language-related domains. Infarct demarcation at 24 h remained frequent, including thalamic involvement in 41% (P1) and 36% (P2). For P1 occlusions, successful reperfusion was associated with less thalamic (29% vs. 83%) and occipital (52% vs. 83%) infarct demarcation. Any intracranial hemorrhage occurred in 13% without segment differences; in-hospital mortality was 26%. Conclusion P1 and P2 segment occlusions showed distinct clinical phenotypes, while EVT was technically feasible with acceptable safety. However, persistent deficits and brain tissue injury were common despite successful reperfusion.