We present a novel patient-specific fluid-solid-growth framework to model the mechanobiological state of clinically detected intracranial aneurysms (IAs) and their evolution. The artery and IA sac are modeled as thick-walled, non-linear elastic fiber-reinforced composites. We represent the undulation distribution of collagen fibers: the adventitia of the healthy artery is modeled as a protective sheath whereas the aneurysm sac is modeled to bear load within physiological range of pressures. Initially, we assume the detected IA is stable and then consider two flow-related mechanisms to drive enlargement: (1) low wall shear stress; (2) dysfunctional endothelium which is associated with regions of high oscillatory flow. Localized collagen degradation and remodelling gives rise to formation of secondary blebs on the aneurysm dome. Restabilization of blebs is achieved by remodelling of the homeostatic collagen fiber stretch distribution. This integrative mechanobiological modelling workflow provides a step towards a personalized risk-assessment and treatment of clinically detected IAs.

我们提出了一种新颖的患者特异性流体-固体生长框架，用于模拟临床检测到的颅内动脉瘤（IA）的力学生物学状态及其演变。动脉和 IA 囊被建模为厚壁、非线性弹性纤维增强复合材料。我们表示胶原纤维的波动分布：健康动脉的外膜被建模为保护鞘，而动脉瘤囊被建模为承受生理压力范围内的负载。最初，我们假设检测到的 IA 是稳定的，然后考虑两种与流动相关的机制来驱动放大：（1）低壁剪切应力；(2)与高振荡流区域相关的功能失调的内皮细胞。局部胶原蛋白降解和重塑导致动脉瘤穹顶上形成继发性泡。通过重塑稳态胶原纤维拉伸分布来实现气泡的重新稳定。这种综合机械生物学建模工作流程为临床检测到的 IAs 的个性化风险评估和治疗迈出了一步。