Study On The Correlation Between FVH-DWI Mismatch And The Outcome Of Acute Middle Cerebral Artery Occlusive Cerebral Infarction After Thrombectomy

Background and objectiveWith the rapid development and update of neuroimaging technology,especially magnetic resonance technology,the efficacy and safety of mechanical intravascular thrombectomy in the treatment of acute large vessel occlusive ischemic stroke have been widely accepted.Traditional Perfusion weighted imaging(PWI)-Diffusion-weighted imaging(DWI)mismatch,CT perfusion,and CT angiography have been used for clinical evaluation in the emergency department.However,due to the need to inject contrast agents,long operation time and other drawbacks,those skills have been accepted by all.In recent years,many neuroimaging and neurologist have been indulging in looking for a quick and feasible non-invasive imaging method to determine the existence of ischemic penumbra in patients with acute major artery occlusive cerebral infarction in the hyperacute stage.The clinical-diffusion mismatch and magnetic resonance angiograph(MRA)-DWI mismatch carried out earlier have certain clinical application value,but the conventional MRI sequence cannot effectively evaluate the collateral circulation after acute major artery occlusion.Collateral circulation is one of the most important indicators affecting the efficacy and safety of endovascular stent thrombectomy in patients with large artery occlusive cerebral infarction.FVH-DWI mismatch evaluation model was proposed based on the recent discovery of fluid-attenuated inversion recovery hyperintensities(FVH).It may be helpful for the evaluation of collateral circulation in ischemic penumbra.Conventional emergency sequences used in acute ischemic cerebrovascular disease include DWI,MOF-MRA and FLAIR sequences.Studies have observed that when large intracranial vessels occlusion occurs,"tubular" or "snake-shaped" high-signal vascular shadow can appear in the subarachnoid space of the territory of the occlussed arteries in more than 50%of patients,which is FVH,usually located in the cerebral sulina or the surface of the brain.Though its finite meaning,some studies have found that FVH can appear before DWI shows infarction,and can appear in brain tissues outside of the DWI focus area,which is called FVH-DWI mismatch.Some scholars believe that it is an effective evaluation index that those patients with FVH-DWI mismatch can benefit from thrombus recanalization surgery.Based on the above study,This article attempts to use the FVH-DWI mismatch model to evaluate the safety and effectiveness of patients with acute middle cerebral artery occlusion(MCAO)after endovascular recanalization.At the same time,compare the two common causes of MCAO:whether there is a difference in the incidence of FVH-DWI mismatch between cardiogenic cerebral embolism and atherosclerotic arterial formation.Try to explain:(1)the reference value of FVH-DWI in the treatment of stent thrombus removal after acute middle cerebral artery occlusion;(2)whether the collateral circulation of MCAO patients caused by cardiogenic cerebral embolism and large atherosclerotic cerebral infarction is different.MethodRetrospectively selected 397 patients with acute major artery occlusive cerebral infarction who underwent emergency MRI sequence screening in our center.Patients diagnosed with acute MCAO M1 occlusion and treated with emergency Solitaire AB stent thrombolysis(n=152)were recruited for baseline clinical data,emergency MRI sequence information,and a complete 3M follow-up record(n=77).Emergency MRI sequences completed preoperatively,including DWI,FLAIR and 3D-TOF-MRA,were analyzed to determine whether there was a mismatch between the FVH-aspect cortical domain(insula,M1-M6)and the corresponding region of DWI-aspect(FVH-DWI mismatch).Definition of FVH-DWI mismatch:FLAIR vascular high-intensity(FVH)can still be found outside the lesion boundary of DWI,that is,FVH occurs outside the lesion of DWI.FVH-DWI mismatch is also considered when lesions shown by DWI appear only in the basal ganglia region and FVH appears in the cortical region of Aspects M1-6.According to the definition,77 patients were divided into FVH-DWI mismatch group(n=35)and no FVH-DWI mismatch group(n=42).According to the prognosis 3 months after surgery,they were divided into good prognosis group(modified MRS ≤2,n=40)and poor prognosis group(MRS>2,n=37).Univariate and Logistic regression were used to analyze the correlation factors and independent influencing factors.Seventy-seven patients were classified by TOAST,and baseline data(including the incidence of FVH-DWI mismatch)were compared between the cardiac atrial fibrillation(CE)group and the aortic atherosclerosis(LAA)group.ResultsA total of 77 patients were included,including 40 patients(51.95%)in the good prognosis group and 37 patients(48.05%)in the poor prognosis group.Univariate correlation analysis showed that hypertension in the good prognosis group(65.00%vs 86.49%;P=0.029),baseline NIHSS score(11.60±4.44 vs 16.92±9.05;P=0.001)was significantly lower than that in the poor prognosis group,while the incidence of FVH-DWI mismatch was significantly higher than that in the poor prognosis group(60.00%vs 29.73%;P=0.008).Multivariate Logistic regression analysis showed that FVH-DWI mismatch was an independent predictor of good prognosis(OR=0.345,P=0.047,95%CI=0.121-0.984),and stroke severity(baseline NIHSS score)was an independent predictor of poor prognosis(OR=1.133,P=0.006,95%CI=1.036-1.239).The TOAST classification showed 26/77 cases in the CE group,45/77 cases in the LAA group,and 6/77 cases in other etiologies.The NIHSS scores in CE group were significantly higher than those in LAA group(15.96±8.09 vs 9.84±4.29,P<0.001).The incidence of FVH-DWI mismatch in the CE group was only,significantly lower than that in the LAA group,and the difference was statistically significant(23.08%,6/26,vs 57.78%,26/45,P=0.005).ConclusionThe results showed that the FVH-DWI mismatch in emergency sequence magnetic resonance imaging was an independent factor of good outcomes in patients with acute M1 occlusion cerebral infarction treated with mechanical thrombotomy.Baseline NIHSS score(stroke severity)is an independent factor of poor prognosis.The incidence of FVH-DWI mismatch in patients with cerebral embolism of atrial fibrillation after MCAO was lower than that in patients with cerebral infarction of great atherosclerotic artery.