Subclinical leaflet thrombosis (SLT) is a potentially serious complication of aortic valve replacement with a bioprosthetic valve in which blood clots form on the replacement valve. SLT is associated with increased risk of transient ischemic attacks and strokes and can progress to clinical leaflet thrombosis. SLT following aortic valve replacement also may be related to subsequent structural valve deterioration, which can impair the durability of the valve replacement. Because of the difficulty in clinical imaging of SLT, models are needed to determine the mechanisms of SLT and could eventually predict which patients will develop SLT. To this end, we develop methods to simulate leaflet thrombosis that combine fluid-structure interaction and a simplified thrombosis model that allows for deposition along the moving leaflets. Additionally, this model can be adapted to model deposition or absorption along other moving boundaries. We present convergence results and quantify the model's ability to realize changes in valve opening and pressures. These new approaches are an important advancement in our tools for modeling thrombosis in which they incorporate both adhesion to the surface of the moving leaflets and feedback to the fluid-structure interaction.

翻译：亚临床瓣叶血栓形成（SLT）是生物瓣膜主动脉瓣置换术后一种潜在的严重并发症，其特征为置换瓣膜上形成血凝块。SLT与一过性脑缺血发作及中风风险增加相关，并可能进展为临床瓣叶血栓形成。主动脉瓣置换术后出现的SLT还可能与后续结构性瓣膜退化有关，从而影响瓣膜置换的耐久性。由于临床影像学对SLT诊断的困难性，亟需建立模型以阐明SLT的发生机制，并最终预测哪些患者会发展为SLT。为此，我们开发了模拟瓣叶血栓形成的方法，该方法结合了流固耦合作用与简化血栓模型，允许血栓在运动瓣叶表面沉积。此外，该模型可适用于沿其他运动边界的沉积或吸收过程建模。我们给出了收敛性结果，并量化了模型识别瓣膜开合度及压力变化的能力。这些新方法通过同时纳入运动瓣叶表面的黏附作用及对流体结构相互作用的反馈机制，为血栓形成建模工具的发展做出了重要推进。