Probabilistic Computational Analysis of Transcatheter Aortic Valve Leaflet Design

Aortic stenosis (AS) is abnormal narrowing of the aortic valve which partially obstructs outflow of blood from the left ventricle to aorta. Symptomatic AS is associated with a high mortality rate, approximately 50% in the first 2 years, if left untreated [1, 2]. Transcatheter aortic valve (TAV) implantation has been recently developed as an effective endovascular treatment for high-risk AS patients, in which a stented bioprosthetic valve is deployed through a catheter within the diseased aortic valve. Since the first procedure in 2002 [3], there has been an explosive growth in TAV implantation. By the end of 2011, there were 10 TAV companies that had first-in-man implantation data [4]. More than 50,000 TAV implantations have been performed worldwide since 2007. Short-term and medium-term outcomes after TAV implantation are encouraging with significant reduction in rates of death. However, adverse events associated with TAV implantation were reported [5, 6]. Furthermore, long-term durability and safety of these devices are largely unknown and needed to be evaluated and studied carefully [7, 8]. It is widely accepted that valve designs that reduce leaflet stresses are likely to give improved performance in long-term applications. The objective of this study was to quantify the effect of 2D TAV leaflet geometry design on 3D valve stress distribution using probabilistic computational simulation.