Stented valve dynamic behavior induced by polyester fiber leaflet material in transcatheter aortic valve devices

Objective: This study aims at assessing the global dynamic behavior, elastic deformability, closing energy and turbulence of rigid versus deformable stented (RS vs DS) valve systems with deformable and rigid textile ma. terials (DT vs RT) through studying the stent-valve interaction compared to a bioprosthetic material in trans. catheter aortic valves (TAV). Methods: Three 19 mm stented textile TAV designs (RS-DT, RS-RT and DS-RT) with different stent and leaflet properties were tested and compared with a control bioprosthetic TAV (RS-DB) in a left heart simulator flow loot under physiological pressure and flow. Particle Image Velocimetry and high speed imaging were performed Pressure gradients (PG), leakage fractions (LF), Pinwheeling indices (PI), closing energy (E) and Reynolds sheaf stresses (RSS) were calculated. Results: (a) PGs and LFs were 11.86 +/- 0.51 mmHg, 11.70 +/- 0.34%; 8.84 +/- 0.40 mmHg, 29.80 +/- 0.76% 11.59 +/- 0.12 mmHg, 14.23 +/- 1.64%; and 7.05 +/- 0.09 mmHg, 12.08 +/- 0.45% % for RS-DB, RS-DT, RS-RT and DS-RT respectively. (b) PIs were 15.79 +/- 2.34%, 4.36 +/- 0.84%, 2.47 +/- 0.51% and 2.03 +/- 0.33% for RS-DB, RS-DT, RS-RT and DS-RT respectively. (c) E is lowest for DS-RT (0.0010 +/- 0.0002 J) followed by RS-R1 (0.0017 +/- 0.0002 J), RS-DB (0.0023 +/- 0.0004 J) and highest with RS-DT (0.0036 +/- 0.0007 J). (d) At peat systole lowest RSS was obtained with RS-DT (87.82 +/- 0.58 Pa) and highest with DS-RT (122.98 +/- 1.87 Pa). Conclusion: PGs, LFs, PIs and E were improved with DS-RT compared to other textile TAVs and RS-DB. Despite achieving more RSS than the rest of TAVs, DS-RT still falls within the same range of RSS produced by the other valves and control exceeding the threshold for platelet activation.