Computational investigation of interaction between stent graft and aorta in retrograde type A dissection after thoracic endovascular aortic repair for type B aortic dissection
Computational investigation of interaction between stent graft and aorta in retrograde type A dissection after thoracic endovascular aortic repair for type B aortic dissection
复制标题
B型主动脉夹层胸主动脉腔内修复术后逆行A型夹层支架与主动脉相互作用的计算研究
DOI：
10.1016/j.jvs.2018.06.008
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发表时间：
2018-12-01
影响因子：
4.3
通讯作者：
Fu, Wei Guo
中科院分区：
文献类型：
--
作者：
Ma, Tao;Dong, Zhi Hui;Fu, Wei Guo
目的：胸主动脉腔内修复术（TEVAR）后的逆行A型夹层（RNTH）一直是血管内治疗的主要缺点。据我们所知，没有研究评价覆膜支架（SG）引起的主动脉损伤。因此，本研究的目的是评估和量化的SG-主动脉的相互作用，并通过计算simulation.Methods：主动脉的几何形状提取从一个Rendezvous的情况下，损伤的危险因素进行分析。根据Valiant和Talent（Medtronic Vascular，圣罗莎，Calif）SG组装了5个SG型号，并通过添加和移除连接杆对原始SG设计进行了修改。结果：在所有的TEVAR模型中，在裸支架近端（PBS）均观察到最大主动脉应力（MAS）。Valiant和Talent SG中的PBS向主动脉壁产生的应力高于其他SG部件。在172.5 mm Valiant模型中，15% OSR（0.54 +/- 0.07 MPa）的MAS显著高于0% OSR（1.32 +/- 0.74 MPa）。带连接杆SG的Talent模型（0.73 +/- 0.24 MPa）的MAS显著高于不带连接杆SG的Talent模型（0.51 +/- 0.11 MPa）。Valiant带连接杆SG模型的MAS（0.82 +/- 0.29 MPa）显著高于Valiant不带连接杆SG模型（0.54 +/- 0.07 MPa）。在OSR为0%的172.5 mm和140 mm Valiant SG置换模型中，MAS无显著差异（0.54 +/- 0.07 MPa vs 0.60 +/- 0.12 MPa）和15% OSR（1.32 +/- 0.74 MPa vs 1.12 +/- 0.33 MPa）。结论：特征性MAS分布保持在PBS顶点与主动脉壁在其较大弯曲处相互作用的位置。较高的OSR和连接杆的存在都可以显著增加SG植入后的MAS。此外，PBS区域的慢性MAS可损伤主动脉壁，引起RHD。（J Vasc Surg 2018;68：14S-21S。）临床相关性：主动脉腔内修复术后，覆膜支架（SG）产生朝向主动脉的应力，可能损伤主动脉壁，导致逆行性A型夹层。然而，不能在体内测量应力。在我们的患者特定计算模型中，我们模拟了SG植入并量化了最大主动脉应力（MAS），并发现了特征性MAS分布。在Valiant和Talent型号的近端裸支架处观察到MAS，在尺寸过大率较高的型号和带连接杆的SG型号中，MAS显著更高。了解SG诱导的主动脉损伤的生物力学行为将使SG设计得以发展。
Objective: Retrograde type A dissection (RTAD) after thoracic endovascular aortic repair (TEVAR) has been a major drawback of endovascular treatment. To our knowledge, no studies have evaluated aortic injuries caused by stent grafts (SGs). Therefore, the aim of this study was to evaluate and to quantify the SG-aorta interaction and to analyze the risk factors for injury through computational simulation.Methods: The aortic geometry was extracted from an RTAD case. Five SG models were assembled based on Valiant and Talent (Medtronic Vascular, Santa Rosa, Calif) SGs, and modifications were made to the original SG design by adding and removing the connecting bar. TEVAR simulations were performed seven times for each SG model with 0% and 15% oversizing ratio (OSR), and the maximum aortic stress (MAS) was calculated and compared within the groups.Results: In all TEVAR models, MAS was seen at the proximal bare stent (PBS). The PBS in the Valiant and Talent SGs generated higher stress toward the aortic wall than other SG parts did. MAS was significantly higher for the 15% OSR (0.54 +/- 0.07 MPa) than for the 0% OSR (1.32 +/- 0.74 MPa) in 172.5- mm Valiant models. MAS was significantly higher in the Talent with connecting bar SG model (0.73 +/- 0.24 MPa) than in the Talent without connecting bar SG model (0.51 +/- 0.11 MPa). MAS was significantly higher in the Valiant with connecting bar SG model (0.82 +/- 0.29 MPa) than in the Valiant without connecting bar SG model (0.54 +/- 0.07 MPa). MAS was not significantly different in models with 172.5- mm and 140-mm Valiant SG implantations with 0% OSR (0.54 +/- 0.07 MPa vs 0.60 +/- 0.12 MPa) and 15% OSR (1.32 +/- 0.74 MPa vs 1.12 +/- 0.33 MPa).Conclusions: The characteristic MAS distribution remained at the location where the apexes of the PBS interacted with the aortic wall at its greater curve. Both higher OSR and the presence of a connecting bar can significantly increase the MAS after SG implantation. Moreover, the chronic MAS at the PBS area may injure the aortic wall, causing RTAD. (J Vasc Surg 2018;68:14S-21S.)Clinical Relevance: After endovascular aortic repair, the stent graft (SG) generates stress toward the aorta and may injure the aortic wall, causing retrograde type A dissection. However, the stress cannot be measured in vivo. In our patient-specific computational models, we simulated SG implantation and quantified the maximum aortic stress (MAS) and found a characteristic MAS distribution. The MAS was seen at the proximal bare stent in Valiant and Talent models and was significantly higher in higher oversizing ratio models and in SG with connecting bar models. The understanding of biomechanical behavior of SG-induced aortic injury will allow SG design to evolve.