<p>Objective: The purpose of this study was to investigate the characteristics, time-line, and treatment results of in-hospital acute ischemic stroke due to large vessel occlusion (LVO) treated by mechanical thrombectomy.</p><p>Methods: The authors investigated 10 patients (six males and four females; mean age 78.6 years, range 65–92) with in-hospital LVO treated by thrombectomy between January 2016 and July 2018 in our institute. Patient characteristics, procedural results, clinical outcome, and time-line data of thrombectomy (last well known [LWK]/onset, recognition, arterial puncture, and recanalization) were retrospectively evaluated. Results obtained from in-hospital LVO were compared with those from 13 patients with community-onset LVO (eight males and five females; mean age 78.3 years, range 45–87).</p><p>Results: The initial admitting departments of in-hospital LVO were cardiology in six (60%) and hematology, otolaryngology, urology, and gastroenterology in one each (10%). The etiologies of ischemic stroke were cardioembolism in eight (80%), thrombosis in one (10%), and iatrogenic consequence in one (10%). The comorbid disease of in-hospital LVO included cardiac disease in eight (80%) and malignant tumor in four (40%) with overlapping. The factor contributing to in-hospital LVO was invasive procedure with withdrawal of antithrombotic agents in three (30%). The interval between LWK and recognition was a median of 60 minutes in in-hospital LVO, which was shorter than LWK-to-arrival time in community-onset LVO (medial 225 minutes). The interval between recognition and consultation to the neuroendovascular team was a median of 50 minutes. The recognition-to-puncture time was compared with arrival-to-puncture time in community-onset LVO. That presented no difference between them (median 130 vs 150 minutes). The LWK-to-recanalization time in in-hospital LVO was shorter than that in community-onset LVO (median 240 vs 495 minutes). The procedural results of thrombectomy demonstrated no differences between them. The rate of thrombolysis in cerebral infarction (TICI) 2b-3 was 70% in in-hospital vs 85% in community-onset LVO. The rate of favorable outcome (modified Rankin Scale [mRS] 0-2) at discharge was not different (30% vs 23%); however, higher rates of mortality and severe disability (mRS 5-6) were observed in patients with in-hospital LVO compared to those with community-onset LVO (40% vs 15%).</p><p>Conclusion: In this series, the procedural results of thrombectomy were not different between in-hospital and community-onset LVO. The recognition-to-puncture time in in-hospital LVO was similar to the arrival-to-puncture time in community-onset LVO, although the LWK-to-recognition/recanalization time in in-hospital LVO was shorter compared with the LWK-to-arrival/recanalization-time in community-onset LVO. The rate of clinical favorable outcome was similar, although a higher rate of poor outcome was observed in in-hospital LVO. Comorbid diseases may be associated with poor outcome in in-hospital ischemic stroke due to LVO.</p>