To evaluate the outcome of mechanical thrombectomy (MT) on large vessel occlusion (LVO) patients with large core infarct volume (CIV). 

Patient selection for MT is guided by symptom onset time and neuroimaging studies. Head CT perfusion with RAPID has widely been used in clinical trials and stroke centers for prompt clinical decision. There is no definitive volume threshold of the CIV for MT; however the CIV with 50ml or less is considered safe for MT.

Charts of consented MT cases with CIV more than 50 ml on RAPID from 2014-Sept 2019 were reviewed. ASPECT score (ASPECTs) of noncontrast head CT (CTH) and infarct volume (IV) of brain MRI were verified independently by two persons. The good outcome was defined as mRS 0-3. ECASS II criteria was used for hemorrhagic transformation on followup CTH. 

Seven cases were identified. Median age was 68 years old. Mean and median CIV was 68 and 71 ml, respectively. Median ASPECTs was 8. One case had ASPECTs 2, while the rest had 6 or higher. Median initial NIHSS was 15 (IQR 14, 18). Median time from the stroke onset to MT was 217 minutes. Five patients (71.4%) had intravenous tPA before MT. Six cases had TICI 2b or 3 re-canalization. Brain MRI median IV was 48 ml, which was about 23 ml less than CIV. Post procedure, two patients didn't have hemorrhage, while two had PH1, two HI2 and one HI1. There was no symptomatic hemorrhage. Median NIHSS on discharge was 3 (IQR 1-6). Three patients had good outcome (42.9%). Three patients (42.9%) were discharged to home, and another three to rehabilitation facilities. The patient with ASPECTs 2 deceased.

Our study suggested that LVO patients having large CIV with favorable ASPECTs may still benefit from MT. A large scale study should be conducted for validation.