Postinterventional contrast accumulation early predicts malignant stroke in successfully recanalized patients with emergent large vessel occlusion

Background and objective: A notable proportion of patients with emergent large vessel occlusion experience malignant middle cerebral infarct (MMI) despite successful recanalization with thrombectomy. In this study, we aim to identify early predictors of MMI in patients successfully recanalized by thrombectomy. Methods: We retrospectively analyzed atotal of 144 anterior circulation emergent large vessel occlusion patients (90 males and 54 females; mean yr & PLUSMN; SD, 67.7 & PLUSMN; 13.2) who were successfully recanalized by thrombectomy (thrombolysis in cerebral infarction perfusion scale 2b or 3) in the cerebrovascular center of the Soonchunhyang University Bucheon Hospital in South Korea between January 2012 and September 2021. Using pretreatment CT angiography source images (CTA-SIs), collateral status was evaluated, and the Alberta stroke program early CT score (ASPECTS) was determined. Contrast accumulation (CA) was evaluated on non-contrast brain CT scans performed immediately after thrombectomy procedures. Logistic regression and receiver operating characteristic curve analyses were performed using SPSS software, version 26. Results: Nineteen patients (13.2 %, 10 males and 9 females; mean yr +/-; SD, 67.9 +/- 11.3) experienced MMI. The collateral status was poorer (p < 0.001) and the CTA-SI ASPECTS was lower (p < 0.001) in the MMI group than in the non-MMI group. Furthermore, postinterventional CA was more frequent in the MMI group (94.7 % vs 65.6 %, p = 0.010). In particular, distribution of CA was different between the MMI and non-MMI groups. Cortical and subarachnoid CA was more frequent in the MMI group than in the non-MMI group (94.7 % vs 49.6 %, p < 0.001 and 89.5 % vs 20.8 %, p < 0.001). In addition, the ASPECTS for CA, wherein each region was scored 0 if CA existed, were lower in the MMI group (p < 0.001). Multivariate analysis showed that cortical CA, subarachnoid CA, and CA ASPECTS were associated with MMI. A CA ASPECTS < 6 predicted MMI with a sensitivity of 94.7 % and a specificity of 77.6 % (area under the curve, 0.87). Conclusions: Our study shows that the MMI risk in successfully recanalized patients can be predicted by using a simple CT scan immediately after thrombectomy. A cortical or subarachnoid location of CA and lower CA AS-PECTS can early predict the future occurrence of MMI.