Clinical Study Of Cervical Arteries Tortuosity And Ischemic Cerebrovascular Disease

Background: Atherosclerotic stenosis and dissection on extracranial carotid artery and vertebral artery are important independent risk factors for ischemic cerebrovascular disease(ICVD),which often leads to transient ischemic attack(TIA)and acute ischemic stroke(AIS)in the ipsilateral cerebral hemisphere,infratentorial cerebellum and brainstem.Cervical large artery occlusion often leads to massive hemispheric infarction in the case of poor collateral circulation compensation,and the prognosis is usually unfavorable without undergoing intravenous thrombolysis or endovascular treatment.In contrast,although tortuosity of cervical artery is also a common clinical vascular morphological change,there are more doubts about the relationship between tortuosity and ICVD than arterial atherosclerosis and dissection.The etiology and pathogenesis of extracranial carotid artery and vertebral artery tortuosity are still unclear.Although most studies believe that vascular tortuosity may be related to aging,sex and hypertension,there are still disputes on many academic issues of concern(such as therelationship between vascular tortuosity and atherosclerosis,whether it is a risk factor or cause of TIA or AIS,etc.),and some domestic and foreign research results also have obvious differences.In addition,the impact of vascular tortuosity on the severity and clinical prognosis of AIS is lack of relevant academic reports.In China,where the prevention and treatment of stroke are increasingly arduous,it is necessary to verify the relationship between extracranial carotid and vertebral arteries tortuosity and ICVD and atherosclerosis by new measurement methods,and further analyze its effect on clinical outcomes,neurological deficits,territory of stroke lesions,age of onset and other aspects of AIS,so as to explore its possible role in the process of ICVD.The future clinical work of stroke prevention and treatment and basic research in related fields will be provided with theoretical basis and practical guidance from these studies.PART ONE: CORRELATION ANALYSIS BETWEEN CERVICAL ARTERIES TORTUOSITY AND ATHEROSCLEROTIC STENOSIS AND ISCHEMIC CEREBROVASCULAR DISEASEObjective: Whether the tortuosity of extracranial internal carotid artery(EICA)and extracranial vertebral artery(EVA)is a risk factor or etiology for ICVD still being controversial,and the relationship between vascular tortuosity and atherosclerosis is still uncertain.The aim of this study was to investigate the correlation of cervical arteries tortuosity with atherosclerotic stenosis and ICVD.Methods: Clinical data of inpatients who underwent angiography of the head and neck in Fifth People’s Hospital of Chongqing from May 2015 to August 2018 was retrospectively analysed.According to the characteristic of ischemic events,the patients were divided into anterior circulation ICVD group,posterior circulation ICVD group and control group.According to the degree of cervical artery stenosis,the patients were divided into severe stenosis group,mild and moderate stenosis group and none stenosis group.The tortuosity index(TI)of EICA and EVA were measured and calculated respectively.Univariate and multivariate analysis were used to explore the correlation between EICA tortuosity and anterior circulation ICVD,EVA tortuosity and posterior circulation ICVD,andbetween vascular tortuosity and atherosclerotic stenosis to explore whether tortuosity of cervical artery is a risk factor of ICVD or atherosclerosis.Results: A total of 323 patients were enrolled in our study.There were102 cases of anterior circulation ICVD,including 92 cases of AIS and 10 cases of TIA.There were 163 cases of ICVD in posterior circulation,including 30 cases of AIS and 133 cases of TIA.Fifty eight patients with no cerebral ischemia were enrolled in the control group.Univariate analysis showed that EICA TI value(P=0.008)and EVA TI value(P=0.001)were significantly different between anterior/posterior circulation ICVD and the control group,respectively.Multivariate analysis with binary Logistic regression showed that EICA TI value(OR=1.036,95% CI 1.007-1.066;P=0.014)and EVA TI value(OR=1.073,95% CI 1.018-1.131;P=0.009)were the independent risk factors for ICVD in anterior and posterior circulation.There were 57,120 and 146 cases in severe stenosis group,mild/moderate stenosis group and none stenosis group,respectively.Univariate analysis showed that the differences of age(P<0.001),sex(P=0.017),hypertension(P<0.001),hyperlipidemia(P=0.034)and diabetes mellitus(P=0.001)among the 3 groups were statistically significant,but no significant statistic differences were found for coronary heart disease(P=0.716),smoking(P=0.610),alcohol consumption(P=0.132),EICA TI value(P=0.086)and EVA TI value(P=0.326).Multivariate analysis with ordinal Logistic regression showed that EICA TI value(OR=1.002,95% CI0.986-1.018;P=0.808)and EVA TI value(OR=0.994,95% CI0.964-1.025;P=0.714)were not independent risk factors for artery stenosis of head and neck.Conclusion: This study demonstrated that tortuosity of EICA and EVA are independent risk factors for anterior and posterior circulation ICVD respectively,but there is no definite evidence to prove the independent correlation between vascular tortuosity and atherosclerotic stenosis.PART TWO: ASSOCIATION BETWEEN EXTRACRANIAL CAROTID ARTERY TORTUOSITY AND CLINICAL OUTCOMES IN ANTERIOR CIRCULATION ACUTE ISCHEMIC STROKEObjective: The tortuosity of extracranial carotid artery may influences successful recanalization rates of mechanical thrombectomy in AIS patients,yet the relationship between vascular tortuosity and the prognosis of patients with anterior circulation AIS who cannot undergo endovascular treatment remains uncertain.The purpose of this study was to investigate the effect of increased tortuosity of extracranial carotid artery(ECA)or EICA on the clinical outcomes in these patients.Methods: Patients with anterior circulation AIS who underwent computed tomography angiography(CTA)of the head and neck in the First Affiliated Hospital of Chongqing Medical University between March 2018 and November 2018 were retrospectively analyzed.The tortuosity index(TI)of EICA and ECA were measured,and functional outcomes were evaluated by a modified Rankin Scale(m RS)at 90 days.Multivariate Logistic regression models and receiver operating characteristic(ROC)curves were used to determine the association between TI values of EICA or ECA and outcomes of patients.Results: A total of 203 patients were enrolled in our study,including 140 patients(68.97%)with favorable outcomes(m RS<3)and 63 patients(31.03%)with unfavorable outcomes(m RS≥3).After adjusting for age,atrial fibrillation,stroke territory,occlusion site of the cerebral artery and post-stroke antithrombotics/statins therapy in multivariate Logistic regression model Ⅰ,the TI values of EICA(OR=1.038,95% CI1.010-1.067;P=0.007)and ECA(OR=1.052,95% CI 1.010-1.096;P=0.015)were independent risks of unfavorable outcomes in enrolled patients.In multivariate Logistic regression model Ⅱ which adjusted for age,sex and baseline NIHSS score,the TI values of EICA(OR=1.038,95% CI 1.008-1.068;P=0.012)and ECA(OR=1.066,95% CI 1.024-1.109;P=0.002)were also showed independent relationship to unfavorable outcomes.The AUC of ROC curve for EICA TI was 0.601(95% CI0.516-0.686;P=0.021),the optimal cutoff to predict the unfavorable outcomes was 14.5,the sensitivity and specificity were 61.9% and 60.7%,respectively(Youden’s index=0.223).The AUC of ECA TI was 0.623(95%CI 0.538-0.708;P=0.005),the optimal cutoff was 12.5,the sensitivity and specificity were 55.6% and 68.3%,respectively(Youden’s index=0.239).Conclusions: Our study demonstrated that the increased tortuosity of EICA and ECA are independent predictors of unfavorable outcomes for anterior circulation AIS patients.The TI value of EICA greater than 14.5 or ECA TI greater than 12.5 may indicate an unfavorable outcome in patients with anterior circulation AIS.The TI value of ECA is more advantageous than EICA to predicting unfavorable outcomes and can be considered as the preferred predictor.PART THREE: EFFECTS OF EXTRACRANIAL CAROTID ARTERY TORTUOSITY ON NEUROLOGICAL DEFICIT,INFARCTION TERRITORY AND AGE IN ANTERIOR CIRCULATION STROKE WITH FIRST ONSETObjective: The second part of this study found that the increase of ECA tortuosity is an independent risk factor for unfavorable outcomes in patients with anterior circulation AIS.On this basis,the effects of ECA or EICA tortuosity on neurological deficit,age,infarct location or territory in anterior circulation AIS with first onset were further analyzed to explore the role of aterial tortuosity in AIS mechanism.Methods: Anterior circulation AIS patients with fist onset in the First Affiliated Hospital of Chongqing Medical University between March 2018 and November 2018 were retrospectively analyzed.The tortuosity index(TI)of EICA and ECA was measured under CTAs of the head and neck respectively.The National Institutes of Health Stroke Scale(NIHSS)was used to assess the degree of neurological deficit at hospital admission.Univariate and multivariate Logistic regression models were used to analyze the relationship between the arterial TI values and the severity of neurological deficits in enrolled patients.The Spearman rank correlation coefficient was used to analyze the correlation between the arterial TI values and the age of first onset and the location or territory of infarct lesions.Results: A total of 175 patients were enrolled in this study,including92 patients(52.6%)with minor stroke(NIHSS score≤3)and 83 patients(47.4%)with moderate and severe neurological deficit(NIHSS score>3).Univariate analysis showed that age,atrial fibrillation,infarction located in the left and bilateral cerebral hemispheres,and occlusion site of the cerebral artery were statistically different between the two groups.Multivariate Logistic regression analysis showed that age(OR=1.037,95%CI 1.006-1.069;P=0.019),infarction located in left cerebral hemisphere(OR=2.462,95% CI 1.240-4.888;P=0.010),carotid artery stem occlusion(OR=9.950,95% CI 1.874-52.825;P=0.007),M1 segment of middle cerebral artery occlusion(OR=36.925,95% CI 4.612-295.651;P=0.001),M2 segment of middle cerebral artery occlusion(OR=3.628,95% CI1.047-12.566;P=0.042)were the independent risk factors of severe condition at admission.However,EICA and ECA TI values were not independently related to the degree of neurological dificit(P>0.05).Spearman rank correlation analysis showed that there was no significant correlation between unilateral carotid artery tortuosity and ipsilateral anterior circulation stroke(P>0.05).The EICA TI value(r S=0.163,P=0.032)and the ECA TI value(r S=0.262,P<0.001)were positively correlated with the age of first stroke onset.Conclusions: Our study demonstrated that EICA and ECA tortuosity were not independent risk factors for the severity of neurological deficit in anterior circulation AIS patients at hospital admission.The tortuosity of EICA and ECA were not significantly correlated with the location or territory of infarction,but positively correlated with the age of first stroke onset.The carotid artery tortuosity does not lead the age of anterior circulation AIS first onset to be advanced.