Hemodynamics Study Of Posterior Circulation Infarction Patients With Vertebral Artery Dominance

Objective:To investigate the pathogenesis of posterior circulation infarction caused by the vertebral artery dominance by studying the changes of posterior circulation vascular hemodynamics in patients with vertebral artery dominance.Methods:186 hospitalized patients diagnosed as posterior circulation infarction were enrolled in this study.All the patients clinical data were collected from January 2017 to December 2017 in Neurology Section of Liaoning Provincial People's Hospital.According to the magnetic resonance angiography(MRA)image,these patients were divided into vertebral artery dominance group and non-vertebral artery dominance group.The superior side of vertebral artery,the diameter of bilateral vertebral artery,the direction of basilar artery bending,the degree of curvature of basilar artery,and the site and side of posterior circulation infarct were recorded respectively.The hemodynamics of intracranial and external segments of vertebral artery and basilar artery were evaluated by color Doppler flow imaging(CDFI)and Transcranial Doppler sonography(TCD).SPSS 24.0 software was used to analyse the statistical data with P<0.05 being considered significant statistical difference.Results:1.186 patients with posterior circulation infarction were enrolled.They were divided into VAD group(n=122,65.6%)and non-VAD group(n=64,34.4%).The constituent ratio of male patients in VAD group was higher than in non-VAD group,and the difference was statistically significant(P<0.05).Significant statistical difference was not seen in the two groups with gender,anamnesis,smoking history and other vascular risk factors,biochemical indicators such as glycerin trilaurate,and the site of posterior circulation infarction.2.The level of peak systolic velocity(PSV),end diastolic velocity(EDV),mean velocity(Vm)in the extracranial dominant VA of VAD group were higher than those in the non-dominant VA of VAD group,and the level of pulsatility index(PI)was lower than those in the non-VAD group with the significant statistical difference(P<0.05).There was no significant difference in resistance index(RI)of extracranial VA in two groups.The level of peak velocity(Vp),diastolic velocity(Vd)and Vm in the intracranial dominant VA of VAD group were higher than those in the non-dominant VA of VAD group,and the level of PI was less than those in the non-VAD group with the significant statistical difference(P<0.05).There was no significant difference in RI of intracranial VA in two groups.3.Compared with BA of two groups the level of Vp and Vd in the VAD group were less than those in the non-VAD group(P<0.05),and the level of RI was higher than those in the non-VAD group(P<0.05).There was on significant difference of Vm and PI in the two groups.4.The difference of vertebral artery diameter on both sides,Vp,Vm and PI had significant statistical difference between the different grades of basilar artery curvature(P<0.05).Further examination by multiple comparisons found:the difference of diameter of vertebral artery on both sides showed significant statistical difference in different grade of basilar artery curvature,between grade 0 and grade 1,grade 1and grade 2(P<0.05).The level of Vp and Vm had statistically significant between grade 1and grade3 of basilar artery curvature(P<0.05).The level of PI had statistically significant between grade 1and grade 2 of basilar artery curvature(P<0.05).Conclusion:1.For the posterior circulation infarction patients with vertebral artery dominance,the velocities of flow in the dominant VA of VAD group were higher than those in the nondominant VA but the level of PI was less.2.By comparing with BA of two groups,the level of Vp and Vd in the VAD group were less than those in the non-VAD group,and the level of RI was higher than those in the non-VAD group.3.The difference in vertebral artery diameter on both sides was paralleled with thedegree of basilar artery bending.With the degree of basilar artery bending increasing,the blood flow velocities decreases gradually.4.Vertebral artery dominance may lead to hemodynamic changes,by causing posterior circulation infarction eventually.There was great clinical value in exploring the pathogenesis of posterior circulation which was caused by hemodynamics of posterior circulation vascular by combining with CDFI and TCD.