目的:颅内动脉瘤生长是破裂的重要危险因素;然而,一些动脉瘤长时间未破裂,即使在成长之后。这里,我们确定了与动脉瘤生长后破裂相关的血流动力学特征.
方法:我们使用计算流体动力学分析分析了在随访期间生长的9个大脑中动脉瘤。大脑中动脉动脉瘤的生长模式分为同质生长(1型),从头气泡形成(类型2),和气泡扩大(类型3)。将生长后四个破裂动脉瘤的血流动力学参数与五个未破裂动脉瘤的血流动力学参数进行比较。
结果:在9个动脉瘤(78%)中,七个是1型,一个是2型,一个是3型。三个(43%)1型动脉瘤在生长后破裂。破裂1型患者动脉瘤生长后的最大振荡剪切指数明显高于未破裂1型患者(破裂与未破裂:0.455±0.007vs.0.319±0.042,p=0.003)。在类型1的情况下,新出现的高振荡剪切指数区域经常与破裂有关,表示破裂点。在扩大之前,在高压差区域的方向观察到动脉瘤生长。在2型和3型动脉瘤中,最大振荡剪切指数略有下降,然而,压力差值保持不变。在3型动脉瘤中,最大OSI和PD值保持不变.
结论:这项研究表明,血液动力学变化和生长模式变化在使用计算流体动力学分析确定破裂风险中至关重要。高压差区域可以预测动脉瘤扩大方向。此外,在具有同态生长模式的病例中,扩大后的最大振荡剪切指数值高是潜在的破裂危险因素。
OBJECTIVE: Intracranial aneurysm growth is a significant risk factor for rupture; however, a few aneurysms remain unruptured for long periods, even after growth. Here, we identified hemodynamic features associated with aneurysmal rupture after growth.
METHODS: We analyzed nine middle cerebral artery aneurysms that grew during the follow-up period using computational fluid dynamics analysis. Growth patterns of the middle cerebral artery aneurysms were divided into homothetic growth (Type 1), de novo bleb formation (Type 2), and bleb enlargement (Type 3). Hemodynamic parameters of the four ruptured aneurysms after growth were compared with those of the five unruptured aneurysms.
RESULTS: Among nine aneurysms (78%), seven were Type 1, one was Type 2, and one was Type 3. Three (43%) Type 1 aneurysms ruptured after growth. Maximum oscillatory shear index after aneurysmal growth was significantly higher in ruptured Type 1 cases than in unruptured Type 1 cases (ruptured vs. unruptured: 0.455 ± 0.007 vs. 0.319 ± 0.042, p = 0.003). In Type 1 cases, a newly emerged high-oscillatory shear index area was frequently associated with rupture, indicating a rupture point. Aneurysm growth was observed in the direction of the high-pressure difference area before enlargement. In Types 2 and 3 aneurysms, the maximum oscillatory shear index decreased slightly, however, the pressure difference values remain unchanged. In Type 3 aneruysm, the maximum OSI and PD values remained unchanged.
CONCLUSIONS: This study suggests that hemodynamic variations and growth pattern changes are crucial in rupture risk determination using computational fluid dynamics analysis. High-pressure difference areas may predict aneurysm enlargement direction. Additionally, high maximum oscillatory shear index values after enlargement in cases with homothetic growth patterns were potential rupture risk factors.