Risk Factors for the Rupture of Middle Cerebral Artery Bifurcation Aneurysms Using CT Angiography

Background and PurposeTo investigate the clinical and morphological characteristics associated with risk factors for the rupture of bifurcation-type middle cerebral artery aneurysms (MCAAs).MethodsA total of 169 consecutive patients with 177 bifurcation-type MCAAs were reviewed from August 2011 to January 2016. Based on the clinical and morphologic characteristics findings, the risk factors of aneurysm rupture were assessed using statistical methods.ResultsAge, cerebral atherosclerosis, no hypertension, hypertension grade 2 and coronary artery disease (CAD) were negatively correlated with aneurysm rupture. The mean diameter (MD) of the parent and two daughter arteries was negatively correlated with rupture. Aneurysms with irregularity, depth, width, maximum size, aspect ratio, depth-to-width ratio, bottleneck factor, and size ratio were positively correlated with rupture. The multivariate logistic regression model revealed that irregular shape (odds ratio (OR) 2.697) and aspect ratio (OR 3.723) were significantly and positively correlated with rupture, while cerebral atherosclerosis (OR 0.033), CAD (OR 0.080), and MD (OR 0.201) were negatively correlated with rupture. Receiver operating characteristic analysis revealed that the threshold value of the aspect ratio and MD were 0.96 and 2.43 mm, respectively.ConclusionsCerebral atherosclerosis and CAD are protective factors against rupture. Morphological characteristics such as an aneurysm with an irregular shape, a high aspect ratio (>0.96) and a small MD (

背景与目的 本研究旨在探讨与分叉型大脑中动脉动脉瘤（bifurcation-type middle cerebral artery aneurysms, MCAAs）破裂相关危险因素的临床及形态学特征。方法 回顾性分析2011年8月至2016年1月期间收治的169例连续患者共177枚分叉型大脑中动脉动脉瘤。基于临床及形态学特征结果，采用统计学方法评估动脉瘤破裂的危险因素。结果 年龄、脑动脉粥样硬化、无高血压、2级高血压及冠状动脉疾病（coronary artery disease, CAD）与动脉瘤破裂呈负相关。载瘤动脉及两支分支动脉的平均直径（mean diameter, MD）与破裂风险呈负相关。动脉瘤形态不规则、瘤深、瘤宽、最大径、高径比（aspect ratio）、深宽比（depth-to-width ratio）、瓶颈因子（bottleneck factor）及大小比（size ratio）与破裂风险呈正相关。多因素logistic回归分析显示，形态不规则（优势比（odds ratio, OR）=2.697）与高径比（OR=3.723）与动脉瘤破裂呈显著正相关，而脑动脉粥样硬化（OR=0.033）、CAD（OR=0.080）及平均直径（MD，OR=0.201）与破裂风险呈负相关。受试者工作特征（Receiver operating characteristic）分析显示，高径比与平均直径（MD）的临界值分别为0.96与2.43 mm。结论 脑动脉粥样硬化与冠状动脉疾病（CAD）为动脉瘤破裂的保护因素。形态学特征诸如形态不规则、高径比（>0.96）及较小的平均直径（MD）(