1Department of Neurosurgery, Kyoto University Graduate School of Medicine, Kyoto.
5Department of Neurosurgery, Kokura Memorial Hospital, Fukuoka.
J Neurosurg. 2022 Oct 7;138(5):1357-1365. doi: 10.3171/2022.8.JNS22597. Print 2023 May 1.
Growing intracranial aneurysms (IAs) are prone to rupture. Previous cross-sectional studies using postrupture morphology have shown the morphological or hemodynamic features related to IA rupture. Yet, which morphological or hemodynamic differences of the prerupture status can predict the growth and rupture of smaller IAs remains unknown. The purpose of this longitudinal study was to investigate the effects of morphological features and the hemodynamic environment on the growth of IAs at middle cerebral artery (MCA) bifurcations during the follow-up period.
One hundred two patients with MCA M1-2 bifurcation saccular IAs who underwent follow-up for more than 2 years at the authors' institutions between 2011 and 2019 were retrospectively identified. During the follow-up period, cases involving growth of MCA IAs were assigned to the event group, and those with MCA IAs unchanged in size were assigned to the control group. The morphological parameters examined were aneurysmal neck length, dome height, aspect ratio and volume, M1 and M2 diameters and their ratio, and angle configurations among M1, M2, and the aneurysm. Hemodynamic parameters were flow rate and wall shear stress in M1, M2, and the aneurysm, including the aneurysmal inflow rate coefficient (AIRC), defined as the ratio of the aneurysmal inflow rate to the M1 flow rate. Those parameters were compared statistically between the two groups. Correlations between morphological and hemodynamic parameters were also examined.
Eighty-three of 102 patients were included: 25 with growing MCA IAs (event group) and 58 with stable MCA IAs (control group). The median patient age at initial diagnosis was 66.9 (IQR 59.8-72.3) years. The median follow-up period was 48.5 (IQR 36.5-65.6) months. Both patient age and the AIRC were significant independent predictors of the growth of MCA IAs. Moreover, the AIRC was strongly correlated with sharper bifurcation and inflow angles, as well as wider inclination angles between the M1 and M2 arteries.
The AIRC was a significant independent predictor of the growth of MCA IAs. Sharper bifurcation and inflow angles and wider inclination angles between the M1 and M2 arteries were correlated with the AIRC. MCA IAs with such a bifurcation configuration are more prone to grow and rupture.
颅内生长的动脉瘤（IAs）易于破裂。先前使用破裂后形态学的横断面研究表明了与 IA 破裂相关的形态学或血流动力学特征。然而，在破裂前状态下，哪些形态学或血流动力学差异可以预测较小 IAs 的生长和破裂仍不清楚。本纵向研究的目的是探讨在随访期间大脑中动脉（MCA）分叉处，形态特征和血流动力学环境对 IAs 生长的影响。
回顾性分析 2011 年至 2019 年间在作者所在机构接受随访超过 2 年的 102 例 MCA M1-2 分叉部囊状 IAs 患者。在随访期间，将 MCA 瘤体增大的病例分配到事件组，MCA 瘤体大小无变化的病例分配到对照组。检查的形态学参数包括瘤颈长度、瘤顶高度、长宽比和体积、M1 和 M2 直径及其比值以及 M1、M2 和动脉瘤之间的角度配置。血流动力学参数为 M1、M2 和动脉瘤中的流量和壁切应力，包括动脉瘤内流入率系数（AIRC），定义为动脉瘤内流入率与 M1 流量的比值。对两组之间的这些参数进行了统计学比较。还检查了形态学和血流动力学参数之间的相关性。
102 例患者中 83 例纳入：25 例 MCA 瘤体增大（事件组），58 例 MCA 瘤体稳定（对照组）。初始诊断时患者的中位年龄为 66.9（IQR 59.8-72.3）岁。中位随访时间为 48.5（IQR 36.5-65.6）个月。患者年龄和 AIRC 是 MCA 瘤体生长的显著独立预测因素。此外，AIRC 与更陡峭的分叉和流入角度以及 M1 和 M2 动脉之间更宽的倾斜角度密切相关。
AIRC 是 MCA 瘤体生长的显著独立预测因素。更陡峭的分叉和流入角度以及 M1 和 M2 动脉之间更宽的倾斜角度与 AIRC 相关。具有这种分叉结构的 MCA 瘤体更容易生长和破裂。
