Novel Polymeric Valve for Transcatheter Aortic Valve Replacement Applications: In Vitro Hemodynamic Study

Abstract

Transcatheter aortic valve replacement (TAVR) is a minimally-invasive approach for treating severe aortic stenosis. All clinically-used TAVR valves to date utilize chemically-fixed xenograft as the leaflet material. Inherent limitation of the tissue (e.g., calcific degeneration) motivates the search for alternative leaflet material. Here we introduce a novel polymeric TAVR valve that was designed to address the limitations of tissue-valves. In this study, we experimentally evaluated the hemodynamic performance of the valve and compared its performance to clinically-used valves: a gold standard surgical tissue valve, and a TAVR valve. Our comparative testing protocols included: (i) baseline hydrodynamics (ISO:5840-3), (ii) complementary patient-specific hydrodynamics in a dedicated system, and (iii) thrombogenicity. The patient-specific testing system facilitated comparing TAVR valves performance under more realistic conditions. Baseline hydrodynamics results at CO 4-7 L/min showed superior effective orifice area (EOA) for the polymer valve, most-notably as compared to the reference TAVR valve. Regurgitation fraction was higher in the polymeric valve, but within the ISO minimum requirements. Thrombogenicity trends followed the EOA results with the polymeric valve being the least thrombogenic, and clinical TAVR being the most. Hemodynamic-wise, the results strongly indicate that our polymeric TAVR valve can outperform tissue valves.

Glycation and Serum Albumin Infiltration Contribute to the Structural Degeneration of Bioprosthetic Heart Valves

“…All three parameters are important indicators for the clinical assessment of aortic valve stenosis severity 28,[59][60][61] . Although the baseline hydrodynamic performances of unimplanted BHV in pulse simulators have been repeatedly reported [62][63][64] , to the best of our knowledge, we are the first to evaluate the hydrodynamic performances of BHV following in vitro incubations that simulate AGE formation observed in clinical explants. In general, all in vitro incubation conditions resulted in a steady decline in EOA and increases in pressure gradients and peak jet velocities.…”

Polyisobutylene-Based Thermoplastic Elastomers for Manufacturing Polymeric Heart Valve Leaflets: In Vitro and In Vivo Results

“…The ability to control the material properties has given the light to develop medical devices of given patterns to address compelling needs of various medical fields, including cardiothoracic surgery [21,22]. Thus, superior polymeric materials may ensure the development of artificial heart valves able to replicate native valve function and overcome major limitations of commercially available prostheses [23]. Optimal polymeric heart valves should combine the main advantages of tissue and mechanical heart valve prostheses.…”

New Insights into Valve Hemodynamics

“…18 Nevertheless, several such devices are currently being developed and have demonstrated promising experimental results. 16,[19][20][21][22] However, even if polymeric valves do achieve the hemodynamic capabilities of current bioprosthetic valves-with the durability of mechanical valvestheir inability to grow makes them problematic for pediatric use. Tissue-engineered heart valves may, potentially, be able to adjust to both tissue growth and remodeling, therefore ensuring prolonged durability.…”