Correlation analysis between tortuosity of extracranial internal carotid artery and extracranial vertebral artery and acute ischemic stroke

Objective To analyze the correlation between tortuosity of extracranial internal carotid artery (EICA) and extracranial vertebral artery (EVA) and acute ischemic stroke, so as to discuss the causes of vascular tortuosity and the mechanism on inducing stroke. Methods This study included 103 patients with acute ischemic stroke and 103 patients without acute ischemic stroke whose manifestations were headache and dizziness. CTA was used to measure the tortuosity index (TI), deviation degree (DD), tortuosity degree (TD) and angular number (AN) of EICA and EVA. Pearson correlation analysis and Spearman rank correlation analysis were used to analyze the correlations of arterial tortuosity with risk factors for ischemic stroke and vascular morphology. Univariate and stepwise multivariate Logistic regression analysis were used to screen related risk factors for tortuosity of EICA and EVA.  Results The stroke group had higher TI ( P = 0.000, 0.000), DD ( P = 0.000, 0.000), TD ( P = 0.002, 0.000) and AN ( P =0.019, 0.000) of EICA and EVA than those in control group. According to the site of infarction, the stroke group was divided into anterior circulation infarction (ACI) subgroup (N = 73) and posterior circulation infarction (PCI) subgroup (N = 30), and there was no significant difference in above-mentioned vascular morphological indexes between 2 subgroups ( P > 0.05, for all); in each subgroup, there was no significant difference between infarct side and non-infarct side of EICA, and between left and right EVA ( P > 0.05, for all). Nevertheless, the TI ( P = 0.000), DD ( P = 0.000) and TD ( P = 0.045) of EICA in ACI subgroup were higher than those in control group; TI ( P = 0.000), DD ( P = 0.000), TD ( P = 0.000) and AN ( P = 0.046) of EVA in PCI subgroup were higher than those in control group. In stroke group, correlation analysis revealed that TI of EICA was positively correlated with age, cervical artery atherosclerosis (CAS), EICA and EVA morphological indexes (except DD of EVA; P < 0.05, for all), but was negatively correlated with male ( r s = -0.253, P = 0.010); TI of EVA was positively correlated with age, hypertension, morphological indexes of EICA and EVA ( P < 0.05, for all), but negatively correlated with male ( r s =-0.276, P = 0.005). Univariate and stepwise multivariate Logistic regression analysis showed that female (EICA: OR = 1.458, 95% CI: 1.111-5.166, P = 0.016; EVA: OR = 9.092，95%CI: 1.294-63.872, P = 0.026) and age (EICA: O R = 1.050, 95%CI: 1.013-1.088， P = 0.007; EVA: OR = 1.084, 95%CI: 1.003-1.138, P = 0.001) were independent risk factors for tortuosity of EICA and EVA.  Conclusions There are no significant differences between left and right side, anterior and posterior circulation on tortuosity distribution of patients with ischemic stroke. The EICA and EVA morphological indexes of stroke patients was significantly higher than that of non-stroke patients. Female and age are independent risk factors for tortuosity of EICA and EVA. DOI: 10.3969/j.issn.1672-6731.2017.04.010