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

BACKGROUND

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.

OBJECTIVES

The aim was to introduce a new paradigm of pre-TAVR BAV LM and a proof-of-concept for THV geometry improvement.

METHODS

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 (dmax/dmin), expansion ratio (opening area/nominal manufacturer's valve area), and eccentricity (1-dmin/dmax)x100%.

RESULTS

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.

CONCLUSIONS

In this proof-of-concept study, pre-TAVR BAV LM presents a promising adjunctive technique to promote THV expansion and circularity.