The Correlation Between Collateral Circulation And Cerebral Perfusion In Ischemic Area Of Patients With Symptomatic Middle Cerebral Artery Disease

Objectives: To investigate the correlation between collateral circulation and cerebral perfusion in ischemic area of patients with symptomatic middle cerebral artery disease.To analyze the influence of different factors on the establishment of cerebral collateral circulation and the effect of different cerebral collateral circulation on the types of cerebral infarction,in order to provide basis for the individualized decision of clinical treatment and the evaluation of prognosis.Methods: 56 patients with symptomatic severe stenosis/occlusion of MCA(M1)had been recruited from the Department of Neurology in Dalian university Hospital during January 2017 to December 2017.All cases were examined by Computed Tomography Angiography(CTA)combining with CT Perfusion(CTP)examination within 7 days of onset.They were divided into good collateral circulation group(n=25)and poor collateral circulation group(n=31),according to multi-temporal CTA collateral compensatory grading method.Some factors such as hypertension,smoking,degree of stenosis and NIHSS were collected,which might have correlation with collateral circulation.The changes of cerebral perfusion parameters in 56 subjects were analyzed by measuring the cerebrovascular blood volume(CBV),cerebral blood flow(CBF),mean transit time(MTT),and time to peak(TTP)on CTP images;RCBV,RCBF,RMTT,RTTP which were represented respectively the ratio of ipsilateral to contralateral side of corresponding cerebral perfusion parameters.,were used to compare the differences of the relative perfusion parameters of the MCA territoty between the two groups.The statistical analysis was used to compare the differences of cerebral infarction types between the two groups,in order to explore the influence of collateral circulation on the mechanism of different types of cerebral infarction.Results:1.Analysis of correlative factors of collateral compensative capacity:(1)Compared with the two groups,there was no significant difference in the effects of MCA severe stenosis and occlusion on the establishiment of the collateral circulation(P> 0.05).(2)Compared with the poor collateral circulation group,there was higher proportion of hypertension,lower proportion of smoking in good collateral compensation group.And the difference was significant(P<0.05).2.Compared with the two groups,there was lower NIHSS in good collateral compensation group.And the difference was significant(P<0.05).3 Multivariate logistic regression analysis showsed that smoking(OR 3.846;95%CI= 1.008-14.682;P=0.049)and NIHSS(OR 1.468;95%CI= 1.023-2.108;P=0.037)were correlated with collateral compensation,while hypertension(OR 0.166;95%CI=0.018-1.559;P=0.116)was not correlated with collateral compensation.4.Analysis of correlations between collateral circulation and CTP parameters:(1)Compared with contralateral mirror area,there were significant differences in CBF,CBV,TTP in hypoperfusion area of all subjects(P<0.05).However,there was no significant difference in MTT(P>0.05).(2)Compared with the two groups,there was significant difference in the RCBF(P<0.05).While there were no significant differences in RCBV,RMTT and RTTP(P>0.05).5.Compared with the two groups,the main infarction types were different.The perforating artery infarction was mainly in the good collateral compensation group while the subcortical watershed cerebral infarction was in the poor collateral compensation group.The difference was significant(P<0.05).Conclusions:1.Smoking is one of the independent risk factors of symptomatic MCA severe stenosis/occlusion collateral circulation opening.2.Good collateral circulation can alleviate the early clinical symptoms.3.CT perfusion parameters can accurately evaluate the changes of local brain hemodynamics after cerebrovascular stenosis;Good collateral compensative capacity may help improve cerebral blood flow in the distal ischemic region in patients with MCA severe stenosis/occlusion.4.The collateral circulation capacity varies among different infarction types.The good collateral circulation group tends to be perforator artery infarction,while the poor collateral circulation group tends to be subcortical CWI.