Changes and significance of the posterior circulation blood flow and wall shear stress in patients with vertebral artery hypoplasia / 中国脑血管病杂志

ABSTRACT

Objectives To evaluate the parameter changes of posterior circulation blood flow and wall shear stress in patients with vertebral artery hypoplasia (VAH) and to understand the possible mechanisms of VAH-induced posterior circulation infarction (PCI). Methods A total of 261 consecutive patients with suspected vascular vertigo admitted to the Department of Neurology, People's Hospital of Zhengzhou from October 2014 to January 2016 were enrolled. The vertigo symptom scale (VSS) was used to evaluate the severity of vertigo. All patients completed TCD and high field strength MR examination within 3 d of admission (Tl ,T2 weighted imaging,fluid attenuation inversion recovery [FLAIR] ,diffusion-weighted imaging [DWI],MR angiography [MRA], contrast-enhanced MRA [CEMRA]),and according to the diameter of the vertebral artery combined with the diagnostic criteria of VAH, they were divided into VAH group and non-VAH group, Posterior circulation blood flow velocity (systolic velocity [V,], diastolic velocity [Vd] , mean velocity [V]) , pulsatility index (PI) , resistance index (RI) , mean flow velocity (MFV) ,and wall shear stress (WSS) between the two group were analyzed. The paired or independent sample t test, Mann-Whitney U test and the 2 test were conducted with SPSS19.0 for intra-group or inter-group comparisons. Results Of 261 patients,78 (29.9%) had VAH,26 were complicated with basilar artery hypoplasia,37 were complicated with fetal type posterior circle of Willis,and posterior circulation infarction occurred in 48 (18. 4%). Compared with the non-VAH group, the degree of vertigo of patients was more severe in the VAH group(3[2,4] vs. 3[1,3] ,Z = 2. 29) ,and the incidence of posterior circulation infarction was significantly increased (25. 6% [20/78] vs. 13. 5% (28/183) ,x =5- 34)- The differences were statistically significant (all P 0. 05). Conclusions The incidence of VAH was higher in patients with vertigo and vascular risk factors. VAH affected the posterior circulation hemodynamics, which might be associated with the occurrence of PCI.