| Background and Purposeposterior circulation ischemia(PCI)includes a transient cerebral ischemic epmission(TIA)and post cycle infarction(PCIS).Ischemic stroke is the most common type in stroke diseases.Although the post-circulating infarction only accounts for 20%of the ischemic stroke,it is serious,and its own or complications can often endanger life with high mortality.However,the thrombolysis time window of posterior circulation infarction is long and the risk of hemorrhage after intravenous thrombolysis is low.Therefore,early accurate diagnosis is of great significance for the formulation of reasonable treatment plan.Vertebral artery is an important part of the posterior circulation and its inner diameter and flow are closely related to the blood supply to the posterior circulation.Most people in the population have differences in the inner diameters of bilateral vertebral arteries.When there is a large difference in the inner diameters of bilateral vertebral arteries,it is called vertebral artery dominance(VAD).With the improvement of medical technology and the development of medical imaging technology,many studies have confirmed that bilateral vertebral artery blood flow in VAD patients is significantly changed compared with that in patients with symmetry,and VAD can promote the occurrence of posterior circulation infarction.The slender inner diameter and slow flow of vertebral artery lead to decreased blood flow,which leads to the occurrence of cerebral ischemic disease,and the disease has an impact on hemodynamics.In clinical work,the observation and measurement of ultrasonic doppler spectrum of vertebral artery are often used to indicate ischemic cerebrovascular disease and judge the severity of the disease.The hemodynamics of bilateral vertebral arteries in patients with VAD is often different due to different inner diameters,and the significance of fixed reference values of hemodynamic indexes for disease indication will be weakened if combined with posterior circulation infarction.At present,there are no recognized flow parameters for predicting posterior circulation infarction in patients with VAD,the purpose of this study was to analyze the bilateral vertebral artery blood flow differences in patients with posterior circulation infarction with VAD,search for more significant hemodynamic parameters,improve the application value of ultrasound in disease diagnosis,it also provides reference for clinical diagnosis,treatment and secondary prevention of posterior circulation infarction.Objects and methodsA total of 180 VAD patients admitted to the First Affiliated Hospital of Zhengzhou University from October 2019 to October 2021 were selected.According to MRI and MRA examination results,45 patients with extracranial vertebral artery stenosis or occlusion,posterior circulation infarction with bilateral or dominant lesions,anterior circulation infarction,intracranial vascular malformation,cardiovascular disease and incomplete data were excluded.Finally,135 cases were included and defined as VAD group.Further,80 patients without cerebral infarction-related symptoms in the VAD group were defined as the non-PCI group.Patients clinically diagnosed with PCI were divided into the infarction group(26 cases with infarction)and the TIA group(29 cases without infarction)according to MRI and MRA examination results.Using inner diameter≤2mm as the standard of vertebral artery hypoplasia and the non-pci group was further divided into hypoplasia group(inner diameter≤2mm)and non-hypoplasia group(inner diameter>2mm).Sixty-eight patients with bilateral vertebral artery symmetry without intracranial vascular malformation,extracranial vertebral artery stenosis or occlusion and cardiovascular disease were included in the non-VAD group.Age,sex,systolic blood pressure,diastolic blood pressure,blood glucose,smoking history,etc.,as well as blood lipid indexes including cholesterol(TC),triglyceride(TG),high density lipoprotein(HDL-C),low density lipoprotein(LDL-C),etc.Of all included subjects were collected.Color Doppler was used to detect the direction and properties of blood flow.Spectral Doppler ultrasound was used to obtain peak systolic blood flow velocity(PSV),end diastolic blood flow velocity(EDV)and resistance index(RI).The vertebral artery with the wider inner diameter was recorded as the dominant side and the vertebral artery with the narrower side was recorded as the non-dominant side.The bilateral vertebral artery ΔD(ΔD=D dominant side-D non-dominant side),D ratio(D ratio=D dominant side/D non-dominant side),ΔRI(Δ RI=RI non-dominant side-RI dominant side)of the control group and observation group were calculated.RI ratio(RI ratio = RI non-dominant/RI dominant),ΔRI/ΔD.The different predictive hemodynamic parameters between the TIA group and the infarction group is receiver Operating characteristic(ROC)curve and sensitivity,specificity,area under the curve(AUC)are calculated and 95%confidence interval of AUC,and the cutoff value was calculated;Spearman correlation analysis was used to analyze the correlation between non-dominant side inner diameter and bilateral inner diameter difference,non-dominant side resistance index bilateral resistance index difference on hemodynamics.Result1.Comparison of general data:age,blood glucose,triglyceride,systolic blood pressure and diastolic blood pressure in the non-PCI group were higher than those in the control group,with statistically significant differences(P<0.05);There were no significant differences in smoking history,cholesterol,HDL-C and LDL-C between the two groups(P>0.05).The incidence of plaque in non-PCI group was significantly higher than that in the non-VAD group and the difference was statistically significant(P<0.05).Comparison among the three VAD groups,the age of the infarction group was significantly higher than that of the non-PCI group and TIA group(P<0.05).There was no significant difference in other general information among the three groups(P>0.05).2.Comparison of inner diameter and hemodynamics between the non-PCI group and the non-VAD group:D,PSV and EDV of the non-dominant side in the non-PCI group were all smaller than those in the non-VAD group,with statistical significance(P<0.05).The D of dominant side,ΔD,D ratio in non-PCI group was higher than that in non-VAD group,and the difference was statistically significan(P<0.05).The RI of non-dominant side,ΔRI,RI ratio in the non-PCI group was higher than that in the non-VAD group,and the difference was statistically significant(P<0.001).There was no statistical difference in other indexes(P>0.05).3.Comparison of inner diameter and hemodynamics in VAD group:There was no significant difference in hemodynamics between TIA group and non-PCI group(P>0.05).The RI of non-dominant,RI ratio,ΔRI and ΔRI/ΔD in infarction group were significantly higher than those in TIA group and non-PCI group(P<0.05).There was no statistical significance in bilateral D among the three groups(P>0.05)4.The proportion of vertebral artery hypoplasia in infarction group was significantly higher than that in TIA group and non-PCI group,and the difference was statistically significant(P<0.05).5.In the non-PCI group,there was a negative correlation between the non-dominant side D and ΔD(P<0.001)and no significant correlation between the non-dominant side D and the non-dominant side RI,ΔRI(P>0.05)in the absence of non-VAH group.There was no significant correlation between D of non-dominant side,and ΔD,RI,Δ RI in VAH group(P>0.05).6.ROC curve showed that the predictive values of the indicators with statistical differences in the TIA group and the infarction group were ΔRI,non-dominant RI,RI ratio and ΔRI/ΔD from high to low,among which ΔRI had the highest predictive value,and the cutoff value is 0.125.The specificity is further improved when ΔRI and the RI of non-dominant side are combined.Conclusion1.The severity of atherosclerosis and the incidence of plaque were increased in VAD patients with risk factors.2.The proportion of vertebral artery hypoplasia in posterior circulation infarction is higher,the smaller the inner diameter of the non dominant side,the higher the probability of posterior circulation infarction.3.Vertebral artery D and arteriosclerosis risk factors jointly affect RI and the smaller the D,the more obvious promoting effect on arteriosclerosis.Patients with the same ΔD have different bilateral vertebral artery D and the degree of sclerosis is not consistent.ΔD is not linearly positive correlated with ΔRI.4.In VAD patients clinically diagnosed with PCI,the difference in blood flow dynamics of bilateral vertebral arteries was more significant in patients with posterior circulation infarction than in patients with TIA.ΔRI is the most valuable hemodynamic index to predict posterior circulation infarction,and the cutoff value of RI is 0.125,and the cutoff value of RI of non-dominant side is 0.730.The specificity is further improved when ΔRI and RI non-dominant side are used for joint prediction. |
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