颅内小动脉瘤患者基于心动周期的血流动力学特点及其对瘤体破裂的预测价值

Hemodynamic characteristics of patients with intracranial aneurysm based on cardiac cycle and their predictive value for intracranial aneurysm rupture

目的分析颅内小动脉瘤(瘤体直径<5 mm)患者基于心动周期的血流动力学特点,探讨其对瘤体破裂的预测价值。方法前瞻性收集698例颅内小动脉瘤患者,每隔个6月复查头颅CTA或MRA,随访3年记录瘤体大小及破裂情况。入组后根据头颅CTA成像情况,应用数字医学计算机及有限元软件建立动脉瘤的解剖三维模型,并结合心动周期对模型进行血流动力学分析,记录最后1个心动周期内快速射血期末(t1)、减慢射血期末(t_(2))和舒张期后期(t_(3))的壁面压力(P)、剪切力(WSS)、涡流数(Nv)。比较瘤体破裂与未破裂者的临床资料及心动周期不同时刻的血流动力学参数,分析差异性血流动力学参数与瘤体大小及破裂时间的相关性;采用多因素Logistic回归分析筛选动脉瘤破裂的独立危险因素,并利用受试者工作(ROC)曲线分析危险因素对瘤体破裂的预测价值。结果698例患者中完成随访计划674例,其中3年内发生瘤体破裂38例、未破裂594例、瘤体增大42例(排除);与未破裂者比较,瘤体破裂者女性占比更高、年龄更大、阿司匹林药物服用率更低、糖尿病和高血压患者占比更多,t_(2) WSS较低而t_(3) WSS、t_(3) Nv较高(P均<0.05);瘤体破裂者t_(3) Nv与瘤体大小呈正相关(r=0.239,P<0.05)、破裂时间呈负相关(r=-0.275,P<0.05),t_(3) WSS与破裂时间呈正相关(r=0.216,P<0.05)。Logistic回归分析显示,t_(2) WSS(OR=1.65,95%CI 1.460~3.879)和t_(3) Nv(OR=2.03,95%CI 1.714~4.296)是预测颅内小动脉瘤破裂的独立危险因素,其预测颅内小动脉瘤破裂的ROC曲线下面积分别为0.723(95%CI 0.605~0.837)和0.707(95%CI 0.581~0.741),两者联合曲线下面积为0.842(95%CI 0.801~0.926)。结论颅内小动脉瘤瘤体破裂患者基于心动周期的血流动力学表现为较低的t_(2) WSS和较高的t_(3) WSS、t_(3) Nv,基于心动周期的血流动力学参数t_(2) WSS、t_(3) Nv可以较准确地预测颅内小动脉瘤破裂的风险。

Objective To analyze the hemodynamic characteristics of patients with small intracranial aneurysms(diameter less than 5 mm)based on cardiac cycle and to explore their predictive value for aneurysm rupture.Methods A total of 698 patients with small intracranial aneurysm were collected prospectively and were reviewed by Computed tomography angiography(CTA)or Magnetic Resonance Angiography(MRA)every 6 months.The aneurysm size and rupture were recorded after 3-year follow-up.After enrollment,according to CTA imaging of head,the three-dimensional model based on intracranial aneurysm anatomy was established by digital medical computer software and finite element software,and the hemodynamic analysis was conducted in combination with cardiac cycle.Meanwhile,pressure(P),wall shear stress(WSS)and number of vortices(Nv)were recorded at the end of rapid ejection(t1)and the end of slow ejection(t_(2))and late diastole(t_(3))during the last cardiac cycle.Moreover,we compared the clinical data and hemodynamic parameters of cardiac cycle between the ruptured group and unruptured group and further analyzed the correlation between differential hemodynamic parameters with aneurysm size and rupture time.Finally,the independent risk factors of aneurysm rupture were investigated with multivariate Logistic analysis,and the receiver operating characteristic(ROC)curve was drawn to analyze the predictive value of risk factors for aneurysm rupture.Results Among 698 participants,674 completed the follow-up plan,among whom 38 cases had rupture and 594 cases did not have rupture and 42 cases had aneurysm enlargement(excluded)within 3 years;compared with the unruptured group,ruptured group manifested higher proportion of women,older age,as well as higher prevalence of hypertension and diabetes,lower aspirin use rate,lower t_(2) WSS,higher t_(3) WSS and t_(3) Nv(all P<0.05).The t_(3) Nv was positively correlated with aneurysmal size(r=0.239,P<0.05)and was negatively correlated with rupture time(r=0.216,P<0.05),and meanwhile,t_(3) WSS was significantly correlated with rupture time(r=-0.275,P<0.05).Logistic regression analysis revealed that t_(2) WSS(OR=1.65,95%CI:1.460-3.879)and t_(3) Nv(OR=2.03,95%CI:1.714-4.296)were reliable indicators in predicting aneurysm rupture,and the area under curve was 0.723(95%CI:0.605-0.837)and 0.707(95%CI:0.581-0.741),respectively,and the area under curve of combined use of t_(2) WSS and t_(3) Nv was 0.842(95%CI:0.626-0.926).Conclusion The hemodynamics of aneurysm ruptured patients with small intracranial aneurysm based on cardiac cycle present lower t_(2) WSS,higher t_(3) WSS and t_(3) Nv;hemodynamic parameters t_(2) WSS and t_(3) Nv based on cardiac cycle can accurately predict the risk of rupture of small intracranial aneurysms.