Osswald Anja, Weymann Alexander, Tsagakis Konstantinos, Zubarevich Alina, Thielmann Matthias, Schmack Bastian, Ruhparwar Arjang, Karmonik Christof
Department of Thoracic and Cardiovascular Surgery, West-German Heart and Vascular Center Essen, Essen, Germany.
Translational Imaging Center, Houston Methodist Research Institute, Houston, TX, USA.
J Thorac Dis. 2023 Feb 28;15(2):281-290. doi: 10.21037/jtd-22-1206. Epub 2023 Feb 13.
Distal stent graft induced new entry (dSINE) is an emerging complication after frozen elephant trunk (FET) procedure. The aim of this computational fluid dynamics (CFD) study was to investigate the role of wall shear stress (WSS) after the development of dSINE based on hemodynamic changes.
Aortic diameter and WSS of five patients who developed a dSINE after FET procedure were retrospectively analyzed before and after the occurrence of dSINE. Patient-specific 3-dimentional surface models of the aortic lumen were reconstructed from computed tomography angiographic datasets (pre dSINE: n=5, dSINE: n=5) to perform steady-state CFD simulations with laminar blood flow and zero pressure outlet conditions. WSS was calculated at the level of the stent graft (SG), the landing zone of the SG and at a location further distal to the SG, as well as on the outer and inner curvature of the aorta from SG center to its distal end.
Post dSINE occurrence, median WSS increased significantly from 0.87 [interquartile range (IQR): 0.83-1.03] to 1.55 (IQR: 1.09-2.70) Pa, (P=0.043) within the SG and from 1.22 (IQR: 0.81-1.44) to 1.76 (IQR: 1.55-3.60) Pa, (P=0.043) at the landing zone of the SG. A non-significant increase from 1.22 (IQR: 0.59-3.50) to 2.58 (IQR: 1.16-3.78) Pa, (P=0.686) further downstream was observed. WSS at the outer curvature of the SG was significantly higher compared to WSS at the inner curvature for dSINE.
Adverse hemodynamic conditions in the form of elevated WSS consist inside and at the distal end of the SG as well as at the outer curvature of the aorta, which may contribute to weakening of the aortic wall. These new findings emphasize the relevance and potential of WSS in dSINE for additional adverse events, such as aortic rupture. Further prospective studies are warranted to explore if the combination of clinical parameters with WSS might be useful to decide which patients require an urgent reintervention in terms of a SG extension.
远端支架移植物诱发的新破口（dSINE）是象鼻支架置入术（FET）后出现的一种新的并发症。本计算流体动力学（CFD）研究的目的是基于血流动力学变化，探讨dSINE发生后壁面剪应力（WSS）的作用。
回顾性分析5例FET术后发生dSINE的患者在dSINE发生前后的主动脉直径和WSS。从计算机断层血管造影数据集重建主动脉管腔的患者特异性三维表面模型（dSINE发生前：n = 5，dSINE发生后：n = 5），以在层流和零压力出口条件下进行稳态CFD模拟。在支架移植物（SG）水平、SG的锚定区以及SG更远端的位置，以及从SG中心到其远端的主动脉外曲率和内曲率处计算WSS。
dSINE发生后，SG内的WSS中位数从0.87 [四分位间距（IQR）：0.83 - 1.03]显著增加到1.55（IQR：1.09 - 2.70）Pa，（P = 0.043），SG锚定区的WSS中位数从1.22（IQR：0.81 - 1.44）增加到1.76（IQR：1.55 - 3.60）Pa，（P = 0.043）。在更远端观察到从1.22（IQR：0.59 - 3.50）到2.58（IQR：1.16 - 3.78）Pa的非显著增加，（P = 0.686）。dSINE时，SG外曲率处的WSS显著高于内曲率处的WSS。
以WSS升高形式存在的不良血流动力学状况存在于SG内部、远端以及主动脉外曲率处，这可能导致主动脉壁变薄。这些新发现强调了WSS在dSINE中与其他不良事件（如主动脉破裂）的相关性和潜在联系。有必要进行进一步的前瞻性研究，以探讨临床参数与WSS的结合是否有助于确定哪些患者需要紧急进行SG延伸的再次干预。
