Bicuspid Aortic Valve Leaflet Modification Before Transcatheter Aortic Valve Replacement: A New Paradigm.

Abstract

<h4>Background</h4>Transcatheter aortic valve replacement (TAVR) deployment in bicuspid aortic valve (BAV) can result in deformed transcatheter heart valves (THVs) due to incomplete, irregular, and eccentric stent expansion. Adjunctive pre-TAVR leaflet modification (LM)/splitting techniques may potentially reduce the circumferential leaflet stress exerted by the BAV leaflets on the THV, reduce risk of immediate complications, and improve THV expansion.<h4>Objectives</h4>The aim was to introduce a new paradigm of pre-TAVR BAV LM and a proof-of-concept for THV geometry improvement.<h4>Methods</h4>Computed tomography-based finite element simulations of self-expanding valve (SEV) deployments were performed in 5 BAV anatomies (type 0 and type 1), with and without a single split. An ex vivo reconstructed BAV model with 4 anatomies (type 0 and type 1) was tested on the bench with both SEV and balloon-expandable valve (BEV) deployment before and after performing multiple permutations of mechanical leaflet splitting and postdilatation. Variables examined included THV opening area in cm², ovality (d_max/d_min), expansion ratio (opening area/nominal manufacturer's valve area), and eccentricity (1-d_min/d_max)x100%.<h4>Results</h4>Both the 4 ex vivo bench cases and the 5 computed tomography-based simulation models demonstrated improvement in expansion ratio (up to 33%) and eccentricity (up to 31%) of deployed SEV/BEV THVs with pre-TAVR BAV splitting compared to their deployment in native BAVs without LM. For the BEV deployment in a type 1 bench model, dual pre-TAVR splitting yielded >10% increase in THV area and ∼5% decrease in ovality compared to a single split.<h4>Conclusions</h4>In this proof-of-concept study, pre-TAVR BAV LM presents a promising adjunctive technique to promote THV expansion and circularity.