3D and Computer Simulation Laboratory, IRCCS Policlinico San Donato, San Donato Milanese, Italy.
Department of Civil Engineering and Architecture, University of Pavia, Pavia, Italy.
Comput Biol Med. 2018 Dec 1;103:140-147. doi: 10.1016/j.compbiomed.2018.10.014. Epub 2018 Oct 18.
Thoracic endovascular aortic repair of the ascending aorta is becoming an option for patients considered unfit for open surgery. Such an endovascular procedure requires careful pre-operative planning and the customization of prosthesis design. The patient-specific tailoring of the procedure may call for dedicated tools to investigate virtual treatment scenarios. Given such considerations, the present study shows a computational framework for choosing and deploying stent-grafts via Finite Element Analysis, by supporting the device sizing and selection in a real case dealing with the endovascular treatment of a pseudoaneurysm. In particular, three devices with various lengths and materials were examined. Two off-the-shelf devices were computationally tested: one composed of Stainless Steel rings with a nominal length of 60 mm and another one with Nitinol rings and a distal free flow extension, with a nominal length of 70 mm. In third place, a custom-made stent-graft, also with Nitinol rings and containing both proximal and distal bare extensions with a nominal length of 75 mm, was deployed. The latter solution based on patient morphology and virtually benchmarked in this simulation framework, enhanced the apposition to the wall by reducing the distance between the skirt and the vessel from more than 6 mm to less than 2 mm in the distal sealing zone. Our experience shows that in-silico simulations can help choosing the right endograft for the ascending aorta as well as the right deployment sequence. This process may also encourage vendors to develop new devices for cases where open repair is unfeasible.
胸主动脉腔内修复术已成为不适合开放性手术的患者的一种选择。这种血管内手术需要仔细的术前规划和定制假体设计。为了进行特定于患者的手术定制，可能需要专用工具来研究虚拟治疗方案。鉴于这些考虑因素，本研究展示了一种通过有限元分析选择和部署支架移植物的计算框架，通过支持在处理假性动脉瘤的血管内治疗的实际案例中进行设备尺寸调整和选择。特别是，检查了三种具有不同长度和材料的装置。对两种现成的装置进行了计算测试：一种由标称长度为 60mm 的不锈钢环组成，另一种由标称长度为 70mm 的镍钛诺环和远端自由流延伸段组成。第三，部署了一种定制的支架移植物，也由镍钛诺环组成，包含近端和远端裸区延长段，标称长度为 75mm。基于患者形态的后者解决方案，在该模拟框架中进行了虚拟基准测试，通过将裙边和血管之间的距离从 6mm 以上减少到远端密封区的 2mm 以下，增强了与壁的贴合。我们的经验表明，计算机模拟可以帮助选择适合升主动脉的正确支架移植物以及正确的部署顺序。这一过程也可能鼓励供应商为无法进行开放性修复的病例开发新设备。
