Department of Engineering, Viale Delle Scienze, Università degli Studi di Palermo, Ed.8, 90128, Palermo, Italy.
Department for the Treatment and Study of Cardiothoracic Diseases and Cardiothoracic Transplantation, IRCCS-ISMETT, via Tricomi n.5, 90127, Palermo, Italy.
Med Biol Eng Comput. 2020 Apr;58(4):815-829. doi: 10.1007/s11517-020-02138-4. Epub 2020 Feb 6.
Bicuspid aortic valve (BAV) anatomy has routinely been considered an exclusion in the setting of transcatheter aortic valve implantation (TAVI) because of the large dimension of the aortic annulus having a more calcified, bulky, and irregular shape. The study aims to develop a patient-specific computational framework to virtually simulate TAVI in stenotic BAV patients using the Edwards SAPIEN 3 valve (S3) and its improved version SAPIEN 3 Ultra and quantify stent frame deformity as well as the severity of paravalvular leakage (PVL). Specifically, the aortic root anatomy of n.9 BAV patients who underwent TAVI was reconstructed from pre-operative CT imaging. Crimping and deployment of S3 frame were performed and then followed by fluid-solid interaction analysis to simulate valve leaflet dynamics throughout the entire cardiac cycle. Modeling revealed that the S3 stent frame expanded well on BAV anatomy with an elliptical shape at the aortic annulus. Comparison of predicted S3 deformity as assessed by eccentricity and expansion indices demonstrated a good agreement with the measurement obtained from CT imaging. Blood particle flow analysis demonstrated a backward blood jet during diastole, whereas the predicted PVL flows corresponded well with those determined by transesophageal echocardiography. This study represents a further step towards the use of personalized simulations to virtually plan TAVI, aiming at improving not only the efficacy of the implantation but also the exploration of "off-label" applications as the TAVI in the setting of BAV patients. Graphical abstract Computational frameworks of TAVI in patients with stenotic bicuspid aortic valve.
二叶式主动脉瓣(BAV)解剖结构通常被认为是经导管主动脉瓣植入术(TAVI)的排除因素,因为主动脉瓣环的大尺寸具有更钙化、更大和更不规则的形状。本研究旨在开发一种患者特异性的计算框架,使用 Edwards SAPIEN 3 瓣膜(S3)及其改进版本 SAPIEN 3 Ultra 对狭窄的 BAV 患者进行虚拟模拟 TAVI,并量化支架框架变形以及瓣周漏(PVL)的严重程度。具体来说,对 n.9 名接受 TAVI 的 BAV 患者的术前 CT 成像进行了主动脉根部解剖重建。进行了 S3 框架的卷曲和展开,然后进行了流固耦合分析,以模拟整个心动周期瓣膜小叶的动力学。建模表明,S3 支架框架在 BAV 解剖结构上扩张良好,在主动脉瓣环处呈椭圆形。通过偏心率和扩张指数评估的预测 S3 变形的比较表明,与 CT 成像获得的测量值具有良好的一致性。血液颗粒流分析显示舒张期有向后的血流喷射,而预测的 PVL 流量与经食管超声心动图确定的流量非常吻合。本研究代表了朝着使用个性化模拟虚拟规划 TAVI 迈进的又一步,旨在不仅提高植入的效果,而且探索 TAVI 在 BAV 患者中的“超适应证”应用。
图形摘要 狭窄二叶式主动脉瓣患者 TAVI 的计算框架。