Hemodynamics Of Intracranial Hemorrhage After Middle Cerebral Artery M1 Segment Occlusion And Reperfusion Therapy

Objective:Intracranial hemorrhage(ICH)is one of the most serious complications of reperfusion treatment for acute ischemic stroke(AIS),and is closely related to whole brain and local hemodynamic changes.Hemodynamic parameters such as wall shear stress(WSS)can be obtained based on computational fluid dynamics(CFD).Therefore,the study was to investigate the correlation between hemodynamic parameters derived from CFD and ICH after reperfusion treatment ofA IS caused by M1 segment occlusion of middle cerebral artery(MCA).Materials and Methods:Forty-nine AIS patients with MCA-M1 occlusion were analyzed retrospectively.The general clinical data at admission,contrast-enhanced(CE)magnetic resonance angiography(MRA)at baseline were collected.Thirty patients among them had follow-up CE-MRA data after reperfusion treatment.The occlusion of MCA-M1 segment was confirmed by pretreatment CE-MRA.Patients were divided into ICH group and non-ICH group according to the follow-up non-enhanced head CT scans.The hemodynamics parameters defined as pressure and wall shear stress(WSS)were obtained based on the MRA-CFD models.RP and Rwss were calculated as the ratio of the pressure and WSS at the origin of MCA to that at 1st normal vessel segment near MCA occlusion,respectively.After reperfusion treatment,the RP and Rwss were measured at the same locations.The differences between Rppre Rwsspre and Rppost、Rwsspost were calculated as Rppost-Rppte,Rwsspost-Rwsspre,respectively,which were defined as △RP and △RWSS.The differences in general clinical data,CFD parameters before reperfusion and CFD parameters’ changes after reperfusion were compared between two groups.Logistic regression analysis was used to identify predictors for ICH.Results:49 AIS patients with MCA-M1 occlusion were collected based on baseline MRA-CFD models.Compared to the non-ICH group(n=29),patients with ICH(n=20)showed elder,had a larger number of hypertension,higher high density lipoprotein levels,lower DWI-ASPECTS,lower RP and higher Rwss derived from baseline MRA-CFD models(p<0.05).Multivariate analysis showed that hypertension was independently associated with ICH(p=0.042,OR=19.553,95%CI 1.114-343.05).30 out of 49 patients had follow-up CE-MRA examinations.Based on MRA-CFD models after reperfusion,ICH group(n=11)characterized by higher baseline systolic blood pressure,lower baseline DWI-ASPECTS score,higher baseline Rwss and △RP,and lower △Rwss(p<0-05)compared to the non-ICH group(n=19).Multivariate analysis showed that baseline systolic blood pressure(p=0.016,OR=1.087,95%CI1.015-1.163)and baseline DWI-ASPECTS score(p=0.035,OR=0.325,95%CI 0.114-0.924)were independently correlated with ICH.Conclusions:The present study suggested that RP and Rwss derived from MRA-CFD models were correlated with ICH for AIS patients with MCA-M1 occlusion,though they could not be used as independent predictors.