Effect of Balloon‐Expandable Transcatheter Aortic Valve Replacement Positioning: A Patient‐Specific Numerical Model

Abstract

Transcatheter aortic valve replacement (TAVR) has emerged as a life-saving and effective alternative to surgical valve replacement in high-risk, elderly patients with severe calcific aortic stenosis. Despite its early promise, certain limitations and adverse events, such as suboptimal placement and valve migration, have been reported. In the present study, we aim to evaluate the effect of various TAVR deployment locations on the procedural outcome by assessing the risk for valve migration. The deployment of a balloon-expandable Edwards SAPIEN valve was simulated via finite element analysis in a patient-specific calcified aortic root, which was reconstructed from CT scans of a retrospective case of valve migration. The deployment location was parametrized in three configurations and the anchorage was quantitatively assessed based on the contact between the stent and the native valve during the deployment and recoil phases. The proximal deployment led to lower contact area between the native leaflets and the stent which poses higher risk for valve migration. The distal and midway positions resulted in comparable outcomes, with the former providing a slightly better anchorage. The approach presented might be used as a predictive tool for procedural planning in order to prevent prosthesis migration and achieve better clinical outcomes.

Patient-specific simulation of transcatheter aortic valve replacement: impact of deployment options on paravalvular leakage

“…The total contact area was calculated and averaged based on the triangular elements on the surface of the AR so that they are independent on the model mesh density (Bianchi et al 2016). In the first two cases contact area and force drops occurred at the beginning of the recoil phase, when the contact with the balloon was disabled.…”

“…As described in Bianchi et al (Bianchi et al 2016), calcifications were embedded into the soft tissue to better mimic the stenotic morphology (Fig. 2).…”

“…The prosthetic leaflets were excluded from the analysis since it was demonstrated (Bailey et al 2015) that they have negligible impact (< 1% in nodal discrepancy) on the post-deployment stent deformation; therefore, the extra computational cost derived from a more complex interaction to be computed is not justified. Total contact area and force were computed in the two phases and compared across all the configurations (Bianchi et al 2016). …”

“…Computational models have been employed to study the interaction between TAVR stent and aortic native tissue and predict post-procedural device performance from a structural dynamics standpoint (Bianchi et al 2016; McGee et al 2018; Morganti et al 2016; Sturla et al 2016; Wang et al 2014). Recent studies quantified the interaction between the device and the implantation site, as a surrogate measure of PVL, by measuring the gap between the stent (Bosi et al 2018; Morganti et al 2014) or the skirt (Schultz et al 2016) from the native tissue in patient-specific and idealized aortic root (AR) anatomies (Chang et al 2018).…”

Utilizing Computational Fluid Dynamics in Cardiovascular Engineering and Medicine-What You Need to Know. Its Translation to the Clinic/Bedside

“…CFD simulations of the circulation help to shed light on biological ad cardiovascular disease processes and their progression by analyzing those from a biomechanics perspective. Few examples of the numerous CFD applications can be found in: studying the complex relation between pathological hemodynamic flow patterns and lesion-prone regions in coronary atherosclerosis, diagnosing the risk of rupture in abdominal aortic aneurysms (2), cerebral aneurysms, and in vulnerable plaques (3), improving surgical procedures to achieve better clinical outcomes, for example, the growing use of CFD for refining transcatheter aortic valve replacement (TAVR) procedures (4), optimization approaches to improve the hemodynamic performance of mechanical circulatory support (MCS) and cardiovascular devices to enhance their thromboresistance, for example, in coronary and carotid stents and endovascular devices, in prosthetic heart valves (5,6), ventricular assist devices (VADs) (7), and in the total artificial heart (TAH) (8). …”