Biomechanical assessment of aortic valve stenosis: Advantages and limitations

Aortic valve stenosis (AS) is a frequent and potentially severe disease of the heart. Accurate assessment of AS is a critical factor in determining prognosis and treatment. This paper describes the advantages and limitations of AS assessment from a biomechanical engineering perspective, by contrasting the non-invasive AS diagnostic methods of echocardiography (Echo), computed tomography (CT), magnetic resonance imaging (MRI), computational analysis (CA) including the invasive technique of cardiac catheterization. The findings illustrated that current methods of AS evaluation, with assumptions of an ideal fluid, geometry and governing equations may not apply well to the aortic valve pathology and could increase the uncertainty of the degree of stenosis and valve area. This review suggests an alternative method using CA, which could potentially overcome the pitfalls of other AS assessments that incorporate geometry, pressure recovery and aorta wall compliance, based on the accurate conversion of AS imaging to the numerical modelling. Further, this review highlights the importance of CA boundary conditions, and the role of verification and validation to produce reliable computational results.