Evaluating The Relationship Between Collateral Circulation Assessed By Multimodal Imaging And Endovascular Treatment Efficacy In Patients With Acute Ischemic Stroke Within 6 To 10 Hours After Symptom Onset

Background and Objective:Stroke has the characteristics of high morbidity,mortality and disability rate,and is the first cause of death among Chinese residents.Acute ischemic stroke(AIS)makes up 85 percent of all strokes.Endovascular treatment(EVT)can achieve effective recanalization of acute occluded vessels in AIS patients.After DAWN and DEFUSE 3 published the results,the EVT time window extend from 6 hours to 16-24 hours,but selected patients in both studies underwent rigorous imaging screening.It has become an urgent problem to screen out patients suitable for EVT from patients with a treatment time window exceeding6 hours as soon as possible.As an important way to maintain cerebral blood perfusion in AIS patients,the cerebral collateral circulation can delay the damage of neurons in the ischemic area and buy time for the treatment of vascular recanalization.Previous studies have shown that there is a significant positive correlation between the cerebral collateral circulation and the neurological prognosis in AIS patients within 6 hours treatment time window.Our research team believes that AIS patients with more than 6 hours after symptom onset can still assess their cerebral collateral circulation as one of the screening criteria for EVT,and the assessment result can help predict the EVT efficacy.The purpose of this study was to assess the cerebral collateral circulation in AIS patients caused middle cerebral artery M1 segment acute occlusion with 6-10 hours after symptoms onset by different cerebral collateral circulation scales based on multimodal imaging patterns,including American society of interventional and therapeutic neuroradiology/society of interventional radiology(ASITN/SIT)grading scale based ondigital subtraction angiography(DSA),regional leptomeningeal score(rLMC)based on computed tomography angiography(CTA)and fluid-attenuated inversion recovery vascular hyperintensities-Alberta stroke program early CT score(FVH-ASPECTS)based on magnetic resonance(MR),furthermore to evaluate the relationship between cerebral collateral circulation and EVT efficacy,and the evaluation results of different scales were compared.Methods:The clinical data and imaging data of 61 patients with AIS caused by middle cerebral artery M1 segment acute occlusion admitted continuously to the department of neurology,the Second Affiliated Hospital of Army Medical University on March 1,2018 and December 31,2018 were retrospectively analyzed.The time from the symptoms onset to femoral artery puncture in all patients was 6-10 hours.1.According to DSA,CTA and MR assessment results of cerebral collateral circulation in selected patients,these patients were divided into the group with poor cerebral collateral circulation(DSA: 14 cases;CTA: 21 cases;MR: 20 cases)and the group with good cerebral collateral circulation(DSA: 47 cases;CTA: 40 cases;MR: 41 cases).The consistency between the assessment results of cerebral collateral circulation by CTA and DSA was evaluated,and the consistency between the assessment results of cerebral collateral circulation by MR and DSA was also evaluated.2.Compare baseline data(gender,age,history of hypertension,history of diabetes,history of atrial fibrillation,history of coronary heart disease,history of smoking and history of drinking,time from stroke symptoms onset to imaging examination,time from imaging examination to puncture and prestroke mRS)and outcome indicators [admission NIHSS,admission ASPECTS,rate of effective recanalization,90-day mRS,proportion of patients with good neurological prognosis(90-day mRS 0-2 points),90-day all-cause mortality,incidence of symptomatic intracranial hemorrhage and incidence of post interventional cerebral hyperdensities] between the group with poor cerebral collateral circulation and the group with good cerebral collateral circulation assessed by different imaging patterns.3.Taking poor neurological prognosis(29 cases)and good neurological prognosis(32cases)as dependent variables,the multivariate analysis of above data and three scales of collateral circulation was evaluated.Results:1.The consistency between the assessment results of cerebral collateral circulation by rLMC based on CTA and ASITN/SIR grading scale based on DSA was good(Kappa :0.724,P<0.001),and the consistency between the assessment results of cerebral collateral circulation by FVH-ASPECTS based on MR and ASITN/SIR based on DSA was also good(Kappa:0.678,P<0.001).2.There were no statistical differences in baseline data between the group with poor cerebral collateral circulation and the group with good cerebral collateral circulation(all P > 0.05)assessed by different imaging patterns.The 90-day mRS,90-day all-cause mortality and admission NIHSS in the group with good cerebral collateral circulation were significantly lower than those in the group with poor cerebral collateral circulation(all P <0.05),and the proportion of patients with good neurological prognosis(90-day mRS 0-2points)and admission ASPECTS were significantly higher than those in the group with poor cerebral collateral circulation(all P < 0.05)assessed by different imaging patterns.There were no statistically differences in the incidence of symptomatic intracranial hemorrhage,the incidence of postinterventional cerebral hyperdensities and the rate of effective recanalization between the group with poor cerebral collateral circulation and the group with good cerebral collateral circulation(all P > 0.05)assessd by different imaging patterns.3.The result of multivariate analysis show that ASITN/SIR grading scale(OR=21.460,95%CI:3.457~133.204,P=0.001),rLMC(OR=1.349,95%CI:1.106~1.646,P=0.003)and FVH-ASPECTS(OR=0.183,95%CI:0.064~0.521,P=0.001)are independent factors for neurological prognosis in AIS patients caused by middle cerebral artery M1 segment acute occlusion within 6-10 hours after symptom onset.Conclusions:For AIS patients caused by middle cerebral artery M1 segment acute occlusion within6-10 hours after symptom onset,CTA and MR assessment results of their cerebral collateralcirculation were good consistent with DSA assessment result of their cerebral collateral circulation.The EVT efficacy in patients with good cerebral collateral circulation is better than patients with poor cerebral collateral circulation assessed by multimodal imaging.Assessment results of cerebral collateral circulation in AIS patients caused by middle cerebral artery M1 segment acute occlusion within 6-10 hours after symptom onset can provide evidence for screening patients to EVT and predicting the EVT efficacy.