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Transcatheter Heart Valve With Variable Geometric Configuration: In Vitro Evaluation
Author(s) -
Young Ernest,
Chen JiFeng,
Dong Owen,
Gao Shengqiang,
Massiello Alex,
Fukamachi Kiyotaka
Publication year - 2011
Publication title -
artificial organs
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.684
H-Index - 76
eISSN - 1525-1594
pISSN - 0160-564X
DOI - 10.1111/j.1525-1594.2011.01331.x
Subject(s) - body orifice , calcification , regurgitant fraction , aortic valve , heart valve , geometry , regurgitation (circulation) , stent , cardiology , mathematics , materials science , anatomy , medicine , ejection fraction , heart failure
Clinically, the current transcatheter aortic valve (TAV) technology has shown a propensity for paravalvular leakage; studies have correlated this flaw to increased calcification at the implantation site and with nonideal geometry of the stented valve. The present study evaluated the hydrodynamics of different geometric configurations, in particular the intravalvular considerations. Three TAV devices were made to create a representative, size 26 mm TAV. Hydrodynamics were assessed using a pulse duplicator. The geometries tested were composed of the nominal, elliptical, triangular, and undersized shapes; along with half‐constriction, a conformation in which only a portion of the stent was constrained. The TAVs were assessed for transvalvular pressure gradient (TVG), effective orifice area (EOA), and regurgitant fraction. The nominal‐sized shape posed a larger TVG (6.2 ± 0.3 mm Hg) than other configurations ( P < 0.001) except the undersized valves. EOA of the nominal sized TAV (1.7 ± 0.1 cm 2 ) was smaller than that of the triangular and half‐elliptical versions ( P < 0.001). The half‐ and full‐undersized geometries had EOAs smaller than the nominal type ( P < 0.001). Nominal shape had smaller regurgitation (6.7 ± 1.4%) than all configurations ( P < 0.001) except for the half‐undersized (4.0 ± 0.7, P < 0.001) with no statistically significant difference from the full‐undersized (6.8 ± 1.3, P = 0.724). The testing of variable geometries showed significant differences from the nominal geometry with respect to TVG, EOA, and regurgitant fraction. In particular, many of these nonideal configurations demonstrated an increased intravalvular regurgitation.