Functional Performance of 2 Different Transcatheter Heart Valve Models as Valve-in-Valve Before and After Expansion of the Inspiris Resilia: An In Vitro Study

Objectives Transcatheter aortic valve-in-valve is frequently performed in degenerated surgical valves. Notably, in small-sized surgical valves, bioprosthetic valve fracturing can improve the functional results of the transcatheter heart valve (THV). Therefore, this study aimed to investigate the impact of an expandable surgical valve on the functional improvement of 2 THV models. Methods An Inspiris Resilia (21 mm) and 2 different THV models—the self-expanding Evolut-PRO and the balloon-expandable SAPIEN 3 (each 23 and 26 mm)—were used for hydrodynamic testing at 4 different circulatory conditions in a pulse duplicator. Mean pressure gradient (MPG), effective orifice area (EOA), geometric orifice area (GOA), minimal internal diameter (MID), and pin-wheeling index (PWI) of the THVs were analysed before and after expansion of the Inspiris Resilia with a non-compliant balloon (6 atm). Leaflet kinematics were evaluated by high-speed video recording. The internal and external diameters of Inspiris Resilia were measured with a calliper gauge. Fluoroscopic images were recorded. Results The Inspiris Resilia showed 2 mm enlarged internal and external stent diameters after expansion, which are fluoroscopically visible. EOA and MPG of the THVs as valve-in-valve did not change significantly after the expansion of the Inspiris Resilia. However, the Inspiris Resilia expansion improved leaflet kinematics, resulting in an increased GOA and a decreased PWI of the THVs as valve-in-valve. Conclusions The expansion of the Inspiris Resilia enlarged the stent diameter, resulting in improved leaflet kinematics of the THVs as valve-in-valve. These findings may be helpful for valve-in-valve interventions, especially in small-sized surgical valves.