Abstract
Underexpansion of a self-expanding transcatheter aortic valve (TAVI) is a critical issue that can negatively impact long-term outcomes, including paravalvular leak, valve thrombosis, and increased mortality. This paper provides a comprehensive review of the pathophysiology and consequences of such complications, including three primary mechanisms: (1) infolding, (2) incorrect site of crossing and (3) true underexpansion. It also discusses strategies to address these challenges, including pre-procedural planning and procedural techniques to ensure proper valve deployment and expansion. Mitigating these issues is essential to improving both immediate and long-term outcomes in TAVI patients.