Sano Takanori, Ishida Fujimaro, Tsuji Masanori, Furukawa Kazuhiro, Shimosaka Shinichi, Suzuki Hidenori
Department of Neurosurgery, Mie University Graduate School of Medicine, Tsu, Mie, Japan; Department of Neurosurgery, Ise Red Cross Hospital, Ise, Mie, Japan.
Department of Neurosurgery, Mie Chuo Medical Center, National Hospital Organization, Tsu, Mie, Japan.
World Neurosurg. 2017 Feb;98:868.e5-868.e10. doi: 10.1016/j.wneu.2016.12.047. Epub 2016 Dec 23.
Studies have demonstrated certain hemodynamic characteristics featuring the rupture status of cerebral aneurysms using computational fluid dynamics. These studies were conducted based on the comparison of a large number of ruptured and unruptured aneurysms. However, not only aneurysm size and location but also perianeurysm environment, such as hemorrhage and intracranial pressure, affect hemodynamic changes. We hypothesized that a case in which ruptured and unruptured cerebral aneurysms simultaneously exist in the same location would be an ideal model to demonstrate hemodynamic characteristics of the rupture status.
We report 2 rare cases with subarachnoid hemorrhage, each of which involved 2 aneurysms at the common parent artery. One patient had 2 anterior communicating artery aneurysms, and the other patient had 2 middle cerebral artery aneurysms. Preoperative morphologic and hemodynamic examinations were performed to diagnose the rupture status of the 2 aneurysms, and each ruptured aneurysm was then confirmed during surgical clipping. Morphologic evaluation revealed higher shape indexes in both ruptured aneurysms. Lower wall shear stress, wall shear stress gradient, and aneurysm formation indicator were observed in both ruptured aneurysms. In contrast, ruptured aneurysms had a higher oscillatory shear index and oscillatory velocity index, which was the novel hemodynamic parameter to quantify the fluctuation of flow velocity vector.
Quantitative characterization of the hemodynamic environment can distinguish the rupture status by using appropriate models minimizing certain bias caused by subarachnoid hemorrhage and aneurysm location.
研究已利用计算流体动力学证明了某些血流动力学特征可反映脑动脉瘤的破裂状态。这些研究是基于大量破裂和未破裂动脉瘤的比较进行的。然而，不仅动脉瘤的大小和位置，而且动脉瘤周围环境，如出血和颅内压，都会影响血流动力学变化。我们假设，在同一位置同时存在破裂和未破裂脑动脉瘤的病例将是展示破裂状态血流动力学特征的理想模型。
我们报告2例罕见的蛛网膜下腔出血病例，每例在共同的母动脉上都有2个动脉瘤。1例患者有2个前交通动脉瘤，另1例患者有2个大脑中动脉瘤。术前进行了形态学和血流动力学检查以诊断这2个动脉瘤的破裂状态，然后在手术夹闭过程中证实了每个破裂的动脉瘤。形态学评估显示，两个破裂动脉瘤的形状指数均较高。在两个破裂动脉瘤中均观察到较低的壁面切应力、壁面切应力梯度和动脉瘤形成指标。相比之下，破裂动脉瘤具有较高的振荡切变指数和振荡速度指数，这是量化流速矢量波动的新血流动力学参数。
血流动力学环境的定量表征可以通过使用适当的模型来区分破裂状态，该模型可将蛛网膜下腔出血和动脉瘤位置引起的某些偏差降至最低。
