An In Vitro Model of Aortic Stenosis for the Assessment of Transcatheter Aortic Valve Implantation

Abstract

A significant number of elderly patients with severe symptomatic aortic stenosis are denied surgical aortic valve replacement (SAVR) because of high operative risk. Transcatheter aortic valve implantation (TAVI) has emerged as a valid alternative to SAVR in these patients. One of the main characteristics of TAVI, when compared to SAVR, is that the diseased native aortic valve remains in place. For hemodynamic testing of new percutaneous valves and clinical training, one should rely on animal models. However, the development of an appropriate animal model of severe aortic stenosis is not straightforward. This work aims at developing and testing an elastic model of the ascending aorta including a severe aortic stenosis. The physical model was built based on a previous silicone model and tested experimentally in this study. Experimental results showed that the error between the computer-aided design (CAD) file and the physical elastic model was <5%, the compliance of the ascending aorta was 1.15 ml/mm Hg, the effective orifice area (EOA) of the stenotic valve was 0.86 cm 2 , the peak jet velocity was 4.9 m/s and mean transvalvular pressure gradient was 50 mm Hg, consistent with as severe. An EDWARDS-SAPIEN 26 mm valve was then implanted in the model leading to a significant increase in EOA (2.22 cm 2 ) and a significant decrease in both peak jet velocity (1.29 m/s) and mean transvalvular pressure gradient (3.1 mm Hg). This model can be useful for preliminary in vitro testing of percutaneous valves before more extensive animal and in vivo tests.

An FSEI approach for the assessment of stenotic aortic valve effects on the left heart hemodynamics

“…Accordingly, the mean TPD during systole increases from 12.7 to 42.5 mmHg as the stenosis severity is increased from mild to severe, with important implications on the transmural loads withstood by the heart chambers which are known to increase proportionally. These numerical results in the case of severe AS are in-line with the in-vitro experiments of [40], where a peak jet velocity of 4.9 m/s and mean TPD of 50 mmHg was observed for a HR of 70 bpm. Furthermore, the numerical simulations indicate that a normal cardiac configuration (i.e.…”

The role of Wnt regulation in heart development, cardiac repair and disease: A tissue engineering perspective

“…Current models are capable of recreating diseased 3D tissue in a well-controlled micro-environment to closely mimic pathophysiological condition in cellular density, composition and extracellular matrix proteins [67]. Specific diseases such as cardiac hypertrophy, atherosclerosis and aortic stenosis can be mimicked in a 3D tissue engineered environment [68–71]. Although these studies do not directly investigate the role of Wnt related signaling, its function is essential to obtain contractile cardiac cells from PSCs.…”

Numerical Simulation of Time-Dependent Non-Newtonian Nanopharmacodynamic Transport Phenomena in a Tapered Overlapping Stenosed Artery

“…They also determined wall-shear stresses (WSSs), oscillatory shear index (OSI), and recirculation lengths for different stenosed cases. Further studies have been reported in Yap et al (2010); Boyd et al (2005); Qiao and Zhang (2014); Chakravarty and Mandal (2000); Maleki et al (2014); Riahi et al (2011); Haghighi et al (2015); Mekheimer and Elkot (2012); Hung and Tsai (1996).…”