Analysis Of Influencing Factors And Clinical Outcome Of Malignant Brain Edema After Mechanical Thrombectomy

PurposeThe occurrence of malignant brain edema(MBE)after mechanical thrombectomy(MT)in patients with anterior circulation acute large vascular occlusion stroke(ALVOS)could lead to severe disability and mortality.Therefore,we aimed to investigate the incidence,related variables and the correlation with clinical outcomes of MBE in patients with anterior circulation ALVOS after MT.MethodsA retrospective analysis was made of 280 patients with anterior circulation ALVOS who underwent MT in our hospital from June 2016 to December 2021.A total of 155 patients were included in this study through screening.Baseline clinical information,imaging data and perioperative data of patients were collected.Standard non-contrast CT(NCCT)is used to evaluate the baseline imaging characteristics of patients with anterior circulation ALVOS at admission.Then,based on the follow-up CT scans performed within 72 hours after MT,the patients were classified into MBE and non-MBE group.MBE was defined as a midline shift of ≥5 mm with signs of local brain swelling.Clinical outcomes were measured using the 90-day modified Rankin Scale(m RS)score and the patients were divided into favorable clinical outcome group and poor clinical outcome group.Univariate and multivariate regression analyses were used to analyze the relationship between MBE and clinical outcomes and identify the influencing factors that correlate with MBE.ResultsWe found that of the 155 patients with anterior circulation ALVOS,30(19.4%)patients developed MBE.Univariate analysis showed that there were statistical differences between the MBE group and the non-MBE group in the baseline Alberta stroke project early CT(ASPECT)score,the baseline middle cerebral artery high density sign(HMCAS)present,the baseline signs of early infarct,the angiographic favorable collaterals,the number of retrieval attempts and the favorable revascularization.However,no statistical differences were observed between the MBE group and the non-MBE group in the age,sex,medical history,the National Institutes of Health Stroke Scale(NIHSS)score at admission,Trial of Org 10172 in Acute Stroke Treatment(TOAST)classification,occluded vessel region,time from stroke onset to first CT,time from stroke onset to groin puncture,whether intravenous thrombolysis,whether stent implantation and balloon dilatation(P>0.05).The influencing factors that might lead to MBE were included in the multivariate analysis through univariate analysis.The results showed that lower baseline ASPECT score(OR=0.429,95%CI=0.238-0.773,P=0.005),absent baseline HMCAS(OR=4.576,95%CI=1.352-15.485,P=0.014),angiographic poor collaterals(OR=5.346,95%CI=1.322-21.628,P=0.019),higher retrieval attempts(OR=1.877,95%CI=1.016-3.465,P=0.044),and poor revascularization(m TICI <2b)(OR=11.937,95%CI 2.932-48.602,P=0.001)were independently associated with the occurrence of MBE after MT in patients with anterior circulation ALVOS.68(43.9%)patients had a favorable clinical outcome.The proportion of patients with favorable clinical outcome in MBE group(m RS≤2)was lower than that in non-MBE group.Univariate analysis showed that there were statistical differences between the favorable clinical outcome group and the poor clinical outcome group in the NIHSS score at admission,angiographic favorable collaterals,the number of retrieval attempts and the favorable revascularization.However,no statistical differences were observed between the favorable clinical outcome group and the poor clinical outcome group in the age,sex,medical history,baseline ASPECT score,baseline HMCAS present,baseline signs of early infarct,TOAST classification,occluded vessel region,time from stroke onset to first CT,time from stroke onset to groin puncture,whether intravenous thrombolysis,whether stent implantation and balloon dilatation(P>0.05).Multivariate analysis showed that MBE was negatively correlated with the good clinical prognosis of patients with anterior circulation ALVOS(OR=0.284,95%CI=0.083-0.969,P=0.044).ConclusionThe incidence of MBE after MT in patients with anterior circulation ALVOS was19.4%,which was independently associated with a lower rate of favorable 90-day clinical outcomes.This study found that lower baseline ASPECT score,absent HMCAS at baseline,angiographic poor collaterals,higher retrieval attempts and poor revascularization(m TICI<2b)were independently associated with the occurrence of MBE after MT in patients with anterior circulation ALVOS.