A geometry optimization framework for transcatheter heart valve leaflet design.

Transcatheter aortic valve replacement (TAVR) is an established treatment for patients with severe symptomatic aortic stenosis. It is known and recognized that leaflet geometry has a key role in structural and hemodynamic performance of bioprosthetic heart valves. Excessive mechanical stress on the leaflets will lead to accelerated tissue degeneration and diminished long-term valve durability. The goal of this study was to develop an automatic optimization framework by means of commercially available software packages to reduce maximum stress value of transcatheter aortic valve (TAV) leaflets. Leaflet design was parameterized by 2 s-order non-uniform rational B-splines (NURBS) curves and particle swarm optimization method was used to examine the optimization design space. Optimized leaflet geometry for 23-mm and 26-mm TAVs were obtained under dynamic physiological loading condition. Leaflet stress distributions of the optimized TAV geometries were compared with two commercially available bioprostheses (i) Carpentier-Edwards PERIMOUNT Magna surgical bioprosthesis and (ii) Edwards SAPIEN 3 transcatheter heart valve. A considerable reduction in the maximum in-plane principal stress was observed in the optimized TAV geometries compared to the commercially available bioprostheses. The optimization results underline the opportunity to improve leaflet design in the next generation of TAVs to potentially increase long-term durability of transcatheter heart valves.

[1]  A. Azadani,et al.  High resolution three-dimensional strain mapping of bioprosthetic heart valves using digital image correlation. , 2018, Journal of biomechanics.

[2]  A. Azadani,et al.  Leaflet stress and strain distributions following incomplete transcatheter aortic valve expansion. , 2015, Journal of biomechanics.

[3]  Josef Kiendl,et al.  An anisotropic constitutive model for immersogeometric fluid-structure interaction analysis of bioprosthetic heart valves. , 2018, Journal of biomechanics.

[4]  Ferdinando Auricchio,et al.  A framework for designing patient‐specific bioprosthetic heart valves using immersogeometric fluid–structure interaction analysis , 2018, International journal for numerical methods in biomedical engineering.

[5]  Yuri Bazilevs,et al.  Dynamic and fluid–structure interaction simulations of bioprosthetic heart valves using parametric design with T-splines and Fung-type material models , 2015, Computational mechanics.

[6]  Michael S Sacks,et al.  Modeling the response of exogenously crosslinked tissue to cyclic loading: The effects of permanent set. , 2017, Journal of the mechanical behavior of biomedical materials.

[7]  S. Pocock,et al.  Transcatheter aortic-valve implantation for aortic stenosis in patients who cannot undergo surgery. , 2010, The New England journal of medicine.

[8]  M. Sacks,et al.  Collagen fiber disruption occurs independent of calcification in clinically explanted bioprosthetic heart valves. , 2002, Journal of biomedical materials research.

[9]  B. Walczak,et al.  Particle swarm optimization (PSO). A tutorial , 2015 .

[10]  J. Webb,et al.  Transcatheter aortic valve implantation in 2017: state of the art. , 2017, EuroIntervention : journal of EuroPCR in collaboration with the Working Group on Interventional Cardiology of the European Society of Cardiology.

[11]  M. Sacks,et al.  The biomechanical effects of fatigue on the porcine bioprosthetic heart valve. , 2001, Journal of long-term effects of medical implants.

[12]  W. Roberts,et al.  Structural changes in glutaraldehyde-treated porcine heterografts used as substitute cardiac valves. Transmission and scanning electron microscopic observations in 12 patients. , 1978, The American journal of cardiology.

[13]  Jia Lu,et al.  Dynamic simulation pericardial bioprosthetic heart valve function. , 2006, Journal of biomechanical engineering.

[14]  Maurice Buchbinder,et al.  Transcatheter aortic-valve replacement with a self-expanding prosthesis. , 2014, The New England journal of medicine.

[15]  J. Leipsic,et al.  Transcatheter Aortic‐Valve Replacement with a Balloon‐Expandable Valve in Low‐Risk Patients , 2019, The New England journal of medicine.

[16]  Wei Sun,et al.  Simulated transcatheter aortic valve deformation: A parametric study on the impact of leaflet geometry on valve peak stress , 2017, International journal for numerical methods in biomedical engineering.

[17]  F J Schoen,et al.  Onset and progression of experimental bioprosthetic heart valve calcification. , 1985, Laboratory investigation; a journal of technical methods and pathology.

[18]  Wei Sun,et al.  Comparison of transcatheter aortic valve and surgical bioprosthetic valve durability: A fatigue simulation study. , 2015, Journal of biomechanics.

[19]  A. Azadani,et al.  Characterization of three-dimensional anisotropic heart valve tissue mechanical properties using inverse finite element analysis. , 2016, Journal of the mechanical behavior of biomedical materials.

[20]  F J Schoen,et al.  Biologic determinants of dystrophic calcification and osteocalcin deposition in glutaraldehyde-preserved porcine aortic valve leaflets implanted subcutaneously in rats. , 1983, The American journal of pathology.

[21]  L Gonzalez-Lavin,et al.  Causes of failure and pathologic findings in surgically removed Ionescu-Shiley standard bovine pericardial heart valve bioprostheses: emphasis on progressive structural deterioration. , 1987, Circulation.

[22]  Stuart J Pocock,et al.  Transcatheter versus surgical aortic-valve replacement in high-risk patients. , 2011, The New England journal of medicine.

[23]  A. Azadani,et al.  A Non-Invasive Material Characterization Framework for Bioprosthetic Heart Valves , 2018, Annals of Biomedical Engineering.

[24]  F J Schoen,et al.  Founder's Award, 25th Annual Meeting of the Society for Biomaterials, perspectives. Providence, RI, April 28-May 2, 1999. Tissue heart valves: current challenges and future research perspectives. , 1999, Journal of biomedical materials research.

[25]  I Vesely,et al.  The evolution of bioprosthetic heart valve design and its impact on durability. , 2003, Cardiovascular pathology : the official journal of the Society for Cardiovascular Pathology.

[26]  Andrew S. Mugglin,et al.  Transcatheter Aortic‐Valve Replacement with a Self‐Expanding Valve in Low‐Risk Patients , 2019, The New England journal of medicine.

[27]  Kewei Li,et al.  Simulated Thin Pericardial Bioprosthetic Valve Leaflet Deformation Under Static Pressure-Only Loading Conditions: Implications for Percutaneous Valves , 2010, Annals of Biomedical Engineering.

[28]  Ankush Aggarwal,et al.  Biomechanical Behavior of Bioprosthetic Heart Valve Heterograft Tissues: Characterization, Simulation, and Performance , 2016, Cardiovascular engineering and technology.

[29]  P. Pibarot,et al.  Aortic Bioprosthetic Valve Durability: Incidence, Mechanisms, Predictors, and Management of Surgical and Transcatheter Valve Degeneration. , 2017, Journal of the American College of Cardiology.

[30]  J. Gorman,et al.  Effect of Geometry on the Leaflet Stresses in Simulated Models of Congenital Bicuspid Aortic Valves , 2011, Cardiovascular engineering and technology.

[31]  Arash Kheradvar,et al.  The effects of transcatheter valve crimping on pericardial leaflets. , 2014, The Annals of thoracic surgery.