A Patient-Specific Model of Transcatheter Valve Replacement in a Bicuspid Heart Valve

Bicuspid Aortic Valves (BAVs) are a common congenital heart disease where two cusps of the aortic heart valve become fused together, this leads to two unequally sized leaflets compared to the normal trileaflet valve. Transcatheter Aortic Valves are currently used in off-label treatmet of stenosed BAVs, however, due to the abnormal valve anatomy, debate surrounds the sizing of transcatheter valves. In this study, finite element models were developed to simulate the deployment of two different valves sizes (a 25 mm and a 27 mm) of the Lotus valve into the patient-specific aortic root geometry of a clinical stenosed BAV case. These models were used to investigate and compare the eccentricity, stress and mal-apposition of the two valve sizes. The results demonstrated that the 25 mm valve was the most suitable in terms of eccentricity and stress reduction. It was also shown that the smaller 25 mm valve size did not increase the likelihood of mal-apposition. As the 25 mm valve was deemed suitable based on current sizing algorithms, on the basis of these results traditional annulus measurement and device sizing may be suitable in the case of the Lotus valve.