Li Xiaowei, Yuan Xiaoming, Wen Zan, An Minghua, Bi Wei
Department of Vascular Surgery, The Second Hospital of Hebei Medical University, Shijiazhuang, Hebei, China.
Department of Cardiovascular Surgery, The First Hospital of Qinhuangdao, Qinhuangdao, Hebei, China.
Front Surg. 2024 Aug 8;11:1399230. doi: 10.3389/fsurg.2024.1399230. eCollection 2024.
Some clinicians use endografts to cover half the left subclavian artery (LSA) ostium to cure some cases with insufficient proximal landing zone (PLZ) in thoracic endovascular aortic repair (TEVAR) treatment. We used computational fluid dynamics (CFD) to study the hemodynamic changes in the LSA because they may cause acute thrombosis or arteriosclerosis.
The digital model of the aortic arch was established and named model A, which only included the supraarch branch of the LSA. By directly covering half of the LSA ostium, which was named as model B. All established models were imported into the Gambit grid division software for grid division and were subsequently imported into the Fluent software for hemodynamic numerical simulation and calculation to analyze the related changes in LSA hemodynamic parameters after stent implantation.
Under the same aortic inlet flow, in model B, the local blood flow velocity of the LSA ostium increased and the whole blood flow velocity at the distal end decreased. The average wall shear stress (WSS) of the LSA was significantly decreased. Meanwhile there was an obvious turbulent flow in the LSA lumen, and the related blood flow state was disordered.
CFD research confirmed that the implantation of an endograft covering half the LSA ostium can cause obvious hemodynamic changes, which is likely to cause a long-term arteriosclerosis or acute thrombosis of the LSA, finally increasing the risk of stroke. Once this operation is performed in some specific clinical cases for simplicity and economy, it seems that we should actively antiplatelet and follow up regularly.
在胸主动脉腔内修复术（TEVAR）治疗中，一些临床医生使用腔内移植物覆盖左锁骨下动脉（LSA）开口的一半来治疗近端锚定区（PLZ）不足的病例。我们使用计算流体动力学（CFD）研究LSA中的血流动力学变化，因为这些变化可能导致急性血栓形成或动脉硬化。
建立主动脉弓数字模型并命名为模型A，其仅包括LSA的弓上分支。通过直接覆盖LSA开口的一半，命名为模型B。所有建立的模型都导入到Gambit网格划分软件中进行网格划分，随后导入到Fluent软件中进行血流动力学数值模拟和计算，以分析支架植入后LSA血流动力学参数的相关变化。
在相同的主动脉入口血流条件下，模型B中LSA开口处的局部血流速度增加，远端的整体血流速度降低。LSA的平均壁面剪切应力（WSS）显著降低。同时，LSA管腔内有明显的湍流，相关血流状态紊乱。
CFD研究证实，植入覆盖LSA开口一半的腔内移植物可引起明显的血流动力学变化，这可能导致LSA长期动脉硬化或急性血栓形成，最终增加中风风险。一旦在某些特定临床病例中为简便和经济而进行此操作，似乎我们应积极进行抗血小板治疗并定期随访。
