Thrombus fragmentation during endovascular stroke treatment, such as mechanical thrombectomy, leads to downstream emboli, resulting in poor clinical outcomes. Clinical studies suggest that fragmentation risk is dependent on clot composition. This current study presents the first experimental characterization of the fracture properties of blood clots, in addition to the development of a predictive model for blood clot fragmentation. A bespoke experimental test-rig and compact tension specimen fabrication has been developed to measure fracture toughness of thrombus material. Fracture tests are performed on three physiologically relevant clot compositions: a high fibrin 5% H clot, a medium fibrin 20% H clot, a low-fibrin 40% H clot. Fracture toughness is observed to significantly increase with increasing fibrin content, i.e. red blood cell-rich clots are more prone to tear during loading compared to the fibrin-rich clots. Results also reveal that the mechanical behaviour of clot analogues is significantly different in compression and tension. Finite element cohesive zone modelling of clot fracture experiments show that fibrin fibres become highly aligned in the direction perpendicular to crack propagation, providing a significant toughening mechanism. The results presented in this study provide the first characterization of the fracture behaviour of blood clots and are of key importance for development of next-generation thrombectomy devices and clinical strategies.

中文翻译：

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血块的断裂特性取决于红细胞和纤维蛋白含量

在血管内卒中治疗（例如机械血栓切除术）过程中，血栓破裂会导致下游栓塞，导致临床效果差。临床研究表明，碎片风险取决于血块成分。这项最新研究提出了血凝块破裂特性的第一个实验表征，此外还建立了血凝块破碎预测模型。已经开发了定制的试验测试台和紧凑的拉伸试样制造装置，以测量血栓材料的断裂韧性。对三种生理相关的血块成分进行断裂测试：高血纤蛋白5％H凝块，中血纤蛋白20％H凝块，低血纤蛋白40％H凝块。观察到断裂韧性随着纤维蛋白含量的增加而显着增加，即 与富含纤维蛋白的凝块相比，富含红细胞的凝块在加载过程中更易于撕裂。结果还表明，凝块类似物的机械行为在压缩和拉伸方面显着不同。凝块断裂实验的有限元内聚区建模表明，纤维蛋白纤维在垂直于裂纹扩展的方向上高度对齐，从而提供了显着的增韧机制。这项研究中提供的结果提供了血栓断裂行为的第一个特征，对于开发下一代血栓切除术设备和临床策略至关重要。凝块断裂实验的有限元内聚区建模表明，纤维蛋白纤维在垂直于裂纹扩展的方向上高度对齐，从而提供了显着的增韧机制。这项研究中提供的结果提供了血栓断裂行为的第一个特征，对于开发下一代血栓切除术设备和临床策略至关重要。凝块断裂实验的有限元内聚区建模表明，纤维蛋白纤维在垂直于裂纹扩展的方向上高度对齐，从而提供了显着的增韧机制。这项研究中提供的结果提供了血栓断裂行为的第一个特征，对于开发下一代血栓切除术设备和临床策略至关重要。