Do self-expandable artificial valves offer an advantage over balloon-expandable valves in patients with calcified aortic roots?
PI: Dr Sanjay Pant (Swansea University)
Co-I’s & Collaborators: Dr. Ankush Aggarwal (College of Engineering, Swansea University), Dr. Daniel Obaid and Prof. Alexander Chase (Department of Cardiology, Morriston Hospital)
Project Overview: Aortic stenosis (AS) is the most common valve-related disease characterised by narrowing of the aortic valve. An increasingly common treatment for AS is the transcatheter aortic valve implantation (TAVI) procedure, where an artificial valve is deployed percutaneously through a catheter to replace the diseased valve. Two methods of deployment are commonly available: first, through balloon-expansion of the TAVI device, and second, through utilisation of self-expanding structures that eliminate the need for high balloon pressures. Calcification is a common finding in AS and affects the aortic annulus, leaflets, and the left ventricle outflow tract. Since calcium is significantly stiffer than normal tissue, the geometry of the expanded TAVI device, and hence the functional properties of the artificial valve, depend on both the spatial distribution of calcium and the method of device expansion. The forceful balloon-expansion has been associated with severe complications such as coronary occlusion (by displacement of hard calcium), aortic root injury, and annulus rupture. The clinical question, therefore, is whether self-expandable devices are more suitable in the presence of calcium, and if so what type of spatial calcium distribution can inform on this decision. This project aims to develop a framework to answer this question while accounting for uncertainties in medical images, material properties of calcified tissue, physics-based computer simulations of device deployment, and clinical expectations.