0
Research Papers

Fluid–Structure Interaction Models of Bicuspid Aortic Valves: The Effects of Nonfused Cusp Angles

[+] Author and Article Information
Karin Lavon, Rotem Halevi

Faculty of Engineering,
School of Mechanical Engineering,
Tel Aviv University,
Tel Aviv 6997801, Israel

Gil Marom

Biomedical Engineering Department,
Stony Brook University,
Stony Brook, NY 11794

Sagit Ben Zekry

Echocardiography Laboratory,
Chaim Sheba Medical Center,
Tel Hashomer 52621, Israel

Ashraf Hamdan

Department of Cardiology,
Rabin Medical Center,
Petach Tikva 4941492, Israel

Hans Joachim Schäfers

Department of Thoracic and
Cardiovascular Surgery,
University Hospitals of Saarland,
Homburg 66421, Germany

Ehud Raanani

Department of Cardio-thoracic Surgery,
Chaim Sheba Medical Center,
Tel Hashomer 52621, Israel

Rami Haj-Ali

School of Mechanical Engineering,
Faculty of Engineering,
Tel Aviv University,
Tel Aviv 6997801, Israel

Manuscript received March 20, 2017; final manuscript received October 16, 2017; published online January 19, 2018. Assoc. Editor: Alison Marsden.

J Biomech Eng 140(3), 031010 (Jan 19, 2018) (7 pages) Paper No: BIO-17-1120; doi: 10.1115/1.4038329 History: Received March 20, 2017; Revised October 16, 2017

Bicuspid aortic valve (BAV) is the most common type of congenital heart disease, occurring in 0.5–2% of the population, where the valve has only two rather than the three normal cusps. Valvular pathologies, such as aortic regurgitation and aortic stenosis, are associated with BAVs, thereby increasing the need for a better understanding of BAV kinematics and geometrical characteristics. The aim of this study is to investigate the influence of the nonfused cusp (NFC) angle in BAV type-1 configuration on the valve's structural and hemodynamic performance. Toward that goal, a parametric fluid–structure interaction (FSI) modeling approach of BAVs is presented. Four FSI models were generated with varying NFC angles between 120 deg and 180 deg. The FSI simulations were based on fully coupled structural and fluid dynamic solvers and corresponded to physiologic values, including the anisotropic hyper-elastic behavior of the tissue. The simulated angles led to different mechanical behavior, such as eccentric jet flow direction with a wider opening shape that was found for the smaller NFC angles, while a narrower opening orifice followed by increased jet flow velocity was observed for the larger NFC angles. Smaller NFC angles led to higher concentrated flow shear stress (FSS) on the NFC during peak systole, while higher maximal principal stresses were found in the raphe region during diastole. The proposed biomechanical models could explain the early failure of BAVs with decreased NFC angles, and suggests that a larger NFC angle is preferable in suture annuloplasty BAV repair surgery.

FIGURES IN THIS ARTICLE
<>
Copyright © 2018 by ASME
Your Session has timed out. Please sign back in to continue.

References

Braverman, A. C. , Güven, H. , Beardslee, M. A. , Makan, M. , Kates, A. M. , and Moon, M. R. , 2005, “ The Bicuspid Aortic Valve,” Curr. Probl. Cardiol., 30(9), pp. 470–522. [CrossRef] [PubMed]
Roberts, W. C. , and Ko, J. M. , 2005, “ Frequency by Decades of Unicuspid, Bicuspid, and Tricuspid Aortic Valves in Adults Having Isolated Aortic Valve Replacement for Aortic Stenosis, With or Without Associated Aortic Regurgitation,” Circulation, 111(7), pp. 920–925. [CrossRef] [PubMed]
Cedars, A. , and Braverman, A. C. , 2012, “ The Many Faces of Bicuspid Aortic Valve Disease,” Prog. Pediatr. Cardiol., 34(2), pp. 91–96. [CrossRef]
Thanassoulis, G. , Yip, J. W. L. , Filion, K. , Jamorski, M. , Webb, G. , Siu, S. C. , and Therrien, J. , 2008, “ Retrospective Study to Identify Predictors of the Presence and Rapid Progression of Aortic Dilatation in Patients With Bicuspid Aortic Valves,” Nat. Clin. Pract. Cardiovasc. Med., 5(12), pp. 821–828. [CrossRef] [PubMed]
Siu, S. C. , and Silversides, C. K. , 2010, “ Bicuspid Aortic Valve Disease,” J. Am. Coll. Cardiol., 55(25), pp. 2789–2800. [CrossRef] [PubMed]
Nistri, S. , Sorbo, M. D. , Marin, M. , Palisi, M. , Scognamiglio, R. , and Thiene, G. , 1999, “ Aortic Root Dilatation in Young Men With Normally Functioning Bicuspid Aortic Valves,” Heart, 82(1), pp. 19–22. [CrossRef] [PubMed]
Michelena, H. I. , Desjardins, V. A. , Avierinos, J.-F. , Russo, A. , Nkomo, V. T. , Sundt, T. M. , Pellikka, P. A. , Tajik, A. J. , and Enriquez-Sarano, M. , 2008, “ Natural History of Asymptomatic Patients With Normally Functioning or Minimally Dysfunctional Bicuspid Aortic Valve in the Community,” Circulation, 117(21), pp. 2776–2784. [CrossRef] [PubMed]
Tzemos, N. , Therrien, J. , Thanassoulis, G. , Tremblay, S. , Jamorski, M. T. , Webb, G. D. , and Siu, S. C. , 2008, “ Outcomes in Adults With Bicuspid Aortic Valves,” JAMA, 300(11), pp. 1317–1325. [CrossRef] [PubMed]
Schäfers, H.-J. , Aicher, D. , Langer, F. , and Lausberg, H. F. , 2007, “ Preservation of the Bicuspid Aortic Valve,” Ann. Thorac. Surg., 83(2), pp. S740–S745. [CrossRef] [PubMed]
Svensson, L. G. , Al Kindi, A. H. , Vivacqua, A. , Pettersson, G. B. , Gillinov, A. M. , Mihaljevic, T. , Roselli, E. E. , Sabik, J. F. , Griffin, B. , Hammer, D. F. , Rodriguez, L. , Williams, S. J. , Blackstone, E. H. , and Lytle, B. W. , 2014, “ Long-Term Durability of Bicuspid Aortic Valve Repair,” Ann. Thorac. Surg., 97(5), pp. 1539–1547. [CrossRef] [PubMed]
Sievers, H.-H. , and Schmidtke, C. , 2007, “ A Classification System for the Bicuspid Aortic Valve From 304 Surgical Specimens,” J. Thorac. Cardiovasc. Surg., 133(5), pp. 1226–1233. [CrossRef] [PubMed]
Thubrikar, M. , 1990, The Aortic Valve, CRC Press, Boca Raton, FL.
Sabet, H. Y. , Edwards, W. D. , Tazelaar, H. D. , and Daly, R. C. , 1999, “ Congenitally Bicuspid Aortic Valves: A Surgical Pathology Study of 542 Cases (1991 Through 1996) and a Literature Review of 2,715 Additional Cases,” Mayo Clin. Proc., 74(1), pp. 14–26. [CrossRef] [PubMed]
Balachandran, K. , Sucosky, P. , and Yoganathan, A. P. , 2011, “ Hemodynamics and Mechanobiology of Aortic Valve Inflammation and Calcification,” Int. J. Inflammation, 2011, p. 263870. [CrossRef]
Robicsek, F. , Thubrikar, M. J. , Cook, J. W. , and Fowler, B. , 2004, “ The Congenitally Bicuspid Aortic Valve: How Does It Function? Why Does It Fail?,” Ann. Thorac. Surg., 77(1), pp. 177–185. [CrossRef] [PubMed]
Saikrishnan, N. , Yap, C.-H. , Milligan, N. C. , Vasilyev, N. V. , and Yoganathan, A. P. , 2012, “ In Vitro Characterization of Bicuspid Aortic Valve Hemodynamics Using Particle Image Velocimetry,” Ann. Biomed. Eng., 40(8), pp. 1760–1775. [CrossRef] [PubMed]
Seaman, C. , Akingba, G. , and Sucosky, P. , 2014, “ Steady Flow Hemodynamic and Energy Loss Measurements in Normal and Simulated Calcified Tricuspid and Bicuspid Aortic Valves,” ASME J. Biomech. Eng., 136(4), p. 041001. [CrossRef]
Jermihov, P. N. , 2011, “ Effect of Geometry on the Leaflet Stresses in Simulated Models of Congenital Bicuspid Aortic Valves,” Cardiovasc. Eng. Technol., 2(1), pp. 48–56. [CrossRef] [PubMed]
Conti, C. A. , Della Corte, A. , Votta, E. , Del Viscovo, L. , Bancone, C. , De Santo, L. S. , and Redaelli, A. , 2010, “ Biomechanical Implications of the Congenital Bicuspid Aortic Valve: A Finite Element Study of Aortic Root Function From In Vivo Data,” J. Thorac. Cardiovasc. Surg., 140(4), pp. 890–896. [CrossRef] [PubMed]
Chandran, K. B. , and Vigmostad, S. C. , 2013, “ Patient-Specific Bicuspid Valve Dynamics: Overview of Methods and Challenges,” J. Biomech., 46(2), pp. 208–216. [CrossRef] [PubMed]
Vergara, C. , Viscardi, F. , Antiga, L. , and Luciani, G. B. , 2012, “ Influence of Bicuspid Valve Geometry on Ascending Aortic Fluid Dynamics: A Parametric Study,” Artif. Organs, 36(4), pp. 368–378. [CrossRef] [PubMed]
Marom, G. , 2015, “ Numerical Methods for Fluid–Structure Interaction Models of Aortic Valves,” Arch. Comput. Methods Eng., 22(4), pp. 595–620. [CrossRef]
Vy, P. , Auffret, V. , Badel, P. , Rochette, M. , Le Breton, H. , Haigron, P. , and Avril, S. , 2016, “ Review of Patient-Specific Simulations of Transcatheter Aortic Valve Implantation,” Int. J. Adv. Eng. Sci. Appl. Math., 8(1), pp. 2–24. [CrossRef]
Kamensky, D. , Hsu, M. C. , Yu, Y. , Evans, J. A. , Sacks, M. S. , and Hughes, T. J. R. , 2017, “ Immersogeometric Cardiovascular Fluid–Structure Interaction Analysis With Divergence-Conforming B-Splines,” Comput. Methods Appl. Mech. Eng., 314, pp. 408–472. [CrossRef] [PubMed]
Fedele, M. , Faggiano, E. , Dedè, L. , and Quarteroni, A. , 2017, “ A Patient-Specific Aortic Valve Model Based on Moving Resistive Immersed Implicit Surfaces,” Biomech. Model. Mechanobiol., 16(5), pp. 1779–1803. [CrossRef] [PubMed]
Mao, W. , Caballero, A. , McKay, R. , Primiano, C. , and Sun, W. , 2017, “ Fully-Coupled Fluid-Structure Interaction Simulation of the Aortic and Mitral Valves in a Realistic 3D Left Ventricle Model,” PLoS One, 12(9), pp. 1–21.
Chandra, S. , Rajamannan, N. M. , and Sucosky, P. , 2012, “ Computational Assessment of Bicuspid Aortic Valve Wall-Shear Stress: Implications for Calcific Aortic Valve Disease,” Biomech. Model. Mechanobiol., 11(7), pp. 1085–1096. [CrossRef] [PubMed]
Kuan, M. Y. S. , and Espino, D. M. , 2015, “ Systolic Fluid-Structure Interaction Model of the Congenitally Bicuspid Aortic Valve: Assessment of Modelling Requirements,” Comput. Methods Biomech. Biomed. Eng., 18(12), pp. 1305–1320. [CrossRef]
Katayama, S. , Umetani, N. , Hisada, T. , and Sugiura, S. , 2013, “ Bicuspid Aortic Valves Undergo Excessive Strain During Opening: A Simulation Study,” J. Thorac. Cardiovasc. Surg., 145(6), pp. 1570–1576. [CrossRef] [PubMed]
Marom, G. , Kim, H.-S. , Rosenfeld, M. , Raanani, E. , and Haj-Ali, R. , 2013, “ Fully Coupled Fluid-Structure Interaction Model of Congenital Bicuspid Aortic Valves: Effect of Asymmetry on Hemodynamics,” Med. Biol. Eng. Comput., 51(8), pp. 839–848. [CrossRef] [PubMed]
Weinberg, E. J. , and Kaazempur Mofrad, M. R. , 2008, “ A Multiscale Computational Comparison of the Bicuspid and Tricuspid Aortic Valves in Relation to Calcific Aortic Stenosis,” J. Biomech., 41(16), pp. 3482–3487. [CrossRef] [PubMed]
Cao, K. , and Sucosky, P. , 2015, “ Effect of Bicuspid Aortic Valve Cusp Fusion on Aorta Wall Shear Stress: Preliminary Computational Assessment and Implication for Aortic Dilation,” World J. Cardiovasc. Dis., 5(6), pp. 129–140. [CrossRef]
Aicher, D. , Kunihara, T. , Abou Issa, O. , Brittner, B. , Gräber, S. , and Schäfers, H.-J. , 2011, “ Valve Configuration Determines Long-Term Results After Repair of the Bicuspid Aortic Valve,” Circulation, 123(2), pp. 178–185. [CrossRef] [PubMed]
Schneider, U. , Hofmann, C. , Aicher, D. , Takahashi, H. , Miura, Y. , and Schäfers, H.-J. , 2017, “ Suture Annuloplasty Significantly Improves the Durability of Bicuspid Aortic Valve Repair,” Ann. Thorac. Surg., 103(2), pp. 504–510. [CrossRef] [PubMed]
Della Corte, A. , Body, S. C. , Booher, A. M. , Schaefers, H.-J. , Milewski, R. K. , Michelena, H. I. , Evangelista, A. , Pibarot, P. , Mathieu, P. , Limongelli, G. , Shekar, P. S. , Aranki, S. F. , Ballotta, A. , Di Benedetto, G. , Sakalihasan, N. , Nappi, G. , Eagle, K. A. , Bavaria, J. E. , Frigiola, A. , and Sundt, T. M. , 2014, “ Surgical Treatment of Bicuspid Aortic Valve Disease: Knowledge Gaps and Research Perspectives,” J. Thorac. Cardiovasc. Surg., 147(6), pp. 1749–1757. [CrossRef] [PubMed]
Haj-Ali, R. , Marom, G. , Ben Zekry, S. , Rosenfeld, M. , and Raanani, E. , 2012, “ A General Three-Dimensional Parametric Geometry of the Native Aortic Valve and Root for Biomechanical Modeling,” J. Biomech., 45(14), pp. 2392–2397. [CrossRef] [PubMed]
Mega, M. , Marom, G. , Halevi, R. , Hamdan, A. , Bluestein, D. , and Haj-Ali, R. , 2016, “ Imaging Analysis of Collagen Fiber Networks in Cusps of Porcine Aortic Valves: Effect of Their Local Distribution and Alignment on Valve Functionality,” Comput. Methods Biomech. Biomed. Eng., 19(9), pp. 1002–1008. [CrossRef]
Marom, G. , Peleg, M. , Halevi, R. , Rosenfeld, M. , Raanani, E. , Hamdan, A. , and Haj-Ali, R. , 2013, “ Fluid-Structure Interaction Model of Aortic Valve With Porcine-Specific Collagen Fiber Alignment in the Cusps,” ASME J. Biomech. Eng., 135(10), p. 101001. [CrossRef]
Gundiah, N. , Kam, K. , Matthews, P. B. , Guccione, J. , Dwyer, H. A. , Saloner, D. , Chuter, T. A. M. , Guy, T. S. , Ratcliffe, M. B. , and Tseng, E. E. , 2008, “ Asymmetric Mechanical Properties of Porcine Aortic Sinuses,” Ann. Thorac. Surg., 85(5), pp. 1631–1638. [CrossRef] [PubMed]
Missirlis, Y. F. , and Chong, M. , 1978, “ Aortic Valve Mechanics—Part I: Material Properties of Natural Porcine Aortic Valves,” J. Bioeng., 2(3–4), pp. 287–300. http://europepmc.org/abstract/med/711721 [PubMed]
Kim, H. S. , 2009, “ Nonlinear Multi-Scale Anisotropic Material and Structural Models for Prosthetic and Native Aortic Heart Valves,” Ph.D. thesis, Georgia Institute of Technology, Atlanta, GA. https://smartech.gatech.edu/handle/1853/29671
Marom, G. , Haj-Ali, R. , Rosenfeld, M. , Schäfers, H. J. , and Raanani, E. , 2013, “ Aortic Root Numeric Model: Annulus Diameter Prediction of Effective Height and Coaptation in Post-Aortic Valve Repair,” J. Thorac. Cardiovasc. Surg., 145(2), pp. 406–411. [CrossRef] [PubMed]
Grande-Allen, K. J. , Cochran, R. P. , Reinhall, P. G. , and Kunzelman, K. S. , 2000, “ Re-Creation of Sinuses Is Important for Sparing the Aortic Valve: A Finite Element Study,” J. Thorac. Cardiovasc. Surg., 119(4), pp. 753–763. [CrossRef] [PubMed]
Soncini, M. , Votta, E. , Zinicchino, S. , Burrone, V. , Fumero, R. , Mangini, A. , Lemma, M. , Antona, C. , and Redaelli, A. , 2006, “ Finite Element Simulations of the Physiological Aortic Root and Valve Sparing Corrections,” J. Mech. Med. Biol., 6(1), pp. 91–99. [CrossRef]
Haj-Ali, R. , Dasi, L. P. , Kim, H. S. , Choi, J. , Leo, H. W. , and Yoganathan, A. P. , 2008, “ Structural Simulations of Prosthetic Tri-Leaflet Aortic Heart Valves,” J. Biomech., 41(7), pp. 1510–1519. [CrossRef] [PubMed]
De Hart, J. , Baaijens, F. P. T. , Peters, G. W. M. , and Schreurs, P. J. G. , 2003, “ A Computational Fluid-Structure Interaction Analysis of a Fiber-Reinforced Stentless Aortic Valve,” J. Biomech., 36(5), pp. 699–712. [CrossRef] [PubMed]
Marom, G. , Haj-Ali, R. , Raanani, E. , Schäfers, H.-J. , and Rosenfeld, M. , 2012, “ A Fluid-Structure Interaction Model of the Aortic Valve With Coaptation and Compliant Aortic Root,” Med. Biol. Eng. Comput., 50(2), pp. 173–182. [CrossRef] [PubMed]
Yoganathan, A. P. , Chandran, K. B. , and Sotiropoulos, F. , 2005, “ Flow in Prosthetic Heart Valves: State-of-the-Art and Future Directions,” Ann. Biomed. Eng., 33(12), pp. 1689–1694. [CrossRef] [PubMed]
Wang, S. H. , Lee, L. P. , and Lee, J. S. , 2001, “ A Linear Relation Between the Compressibility and Density of Blood,” J. Acoust. Soc. Am., 109(1), pp. 390–396. [CrossRef] [PubMed]
Mahadevia, R. , Barker, A. J. , Schnell, S. , Entezari, P. , Kansal, P. , Fedak, P. W. M. , Malaisrie, S. C. , McCarthy, P. , Collins, J. , Carr, J. , and Markl, M. , 2014, “ Bicuspid Aortic Cusp Fusion Morphology Alters Aortic Three-Dimensional Outflow Patterns, Wall Shear Stress, and Expression of Aortopathy,” Circulation, 129(6), pp. 673–682. [CrossRef] [PubMed]
Stephens, E. H. , Hope, T. A. , Kari, F. A. , Kvitting, J. P. E. , Liang, D. H. , Herfkens, R. J. , and Miller, D. C. , 2015, “ Greater Asymmetric Wall Shear Stress in Sievers' Type 1/LR Compared With 0/LAT Bicuspid Aortic Valves After Valve-Sparing Aortic Root Replacement,” J. Thorac. Cardiovasc. Surg., 150(1), pp. 59–68. [CrossRef] [PubMed]
Guzzardi, D. G. , Barker, A. J. , Van Ooij, P. , Malaisrie, S. C. , Puthumana, J. J. , Belke, D. D. , Mewhort, H. E. M. , Svystonyuk, D. A. , Kang, S. , Verma, S. , Collins, J. , Carr, J. , Bonow, R. O. , Markl, M. , Thomas, J. D. , McCarthy, P. M. , and Fedak, P. W. M. , 2015, “ Valve-Related Hemodynamics Mediate Human Bicuspid Aortopathy: Insights From Wall Shear Stress Mapping,” J. Am. Coll. Cardiol., 66(8), pp. 892–900. [CrossRef] [PubMed]
Atkins, S. K. , Cao, K. , Rajamannan, N. M. , and Sucosky, P. , 2014, “ Bicuspid Aortic Valve Hemodynamics Induces Abnormal Medial Remodeling in the Convexity of Porcine Ascending Aortas,” Biomech. Model. Mechanobiol., 13(6), pp. 1209–1225. [CrossRef] [PubMed]
Richards, K. E. , Deserranno, D. , Donal, E. , Greenberg, N. L. , Thomas, J. D. , and Garcia, M. J. , 2004, “ Influence of Structural Geometry on the Severity of Bicuspid Aortic Stenosis,” Am. J. Physiol. Heart Circ. Physiol., 287(3), pp. H1410–H1416. [CrossRef] [PubMed]
Miyahara, S. , Abe, N. , Matsueda, T. , Izawa, N. , Yamazato, T. , Nomura, Y. , Kitamura, A. , Sato, S. , Takahashi, H. , Inoue, T. , Matsumori, M. , and Okita, Y. , 2016, “ Impact of Positional Relationship of Commissures on Cusp Function After Valve-Sparing Root Replacement for Regurgitant Bicuspid Aortic Valve,” Eur. J. Cardiothorac. Surg., 50(1), pp. 75–81. [CrossRef] [PubMed]
Vallabhajosyula, P. , Szeto, W. Y. , Komlo, C. M. , Ryan, L. P. , Wallen, T. J. , Gorman, R. C. , Desai, N. D. , and Bavaria, J. E. , 2014, “ Geometric Orientation of the Aortic Neoroot in Patients With Raphed Bicuspid Aortic Valve Disease Undergoing Primary Cusp Repair and a Root Reimplantation Procedure,” Eur. J. Cardiothorac. Surg., 45(1), pp. 174–180. [CrossRef] [PubMed]
Sun, L. , Chandra, S. , and Sucosky, P. , 2012, “ Ex Vivo Evidence for the Contribution of Hemodynamic Shear Stress Abnormalities to the Early Pathogenesis of Calcific Bicuspid Aortic Valve Disease,” PLoS One, 7(10), p. e48843. [CrossRef] [PubMed]
Sun, L. , Rajamannan, N. M. , and Sucosky, P. , 2013, “ Defining the Role of Fluid Shear Stress in the Expression of Early Signaling Markers for Calcific Aortic Valve Disease,” PLoS One, 8(12), p. e84433. [CrossRef] [PubMed]
Halevi, R. , Hamdan, A. , Marom, G. , Lavon, K. , Ben-Zekry, S. , Raanani, E. , Bluestein, D. , and Haj-Ali, R. , 2016, “ Fluid–Structure Interaction Modeling of Calcific Aortic Valve Disease Using Patient-Specific Three-Dimensional Calcification Scans,” Med. Biol. Eng. Comput., 54(11), pp. 1683–1694. [CrossRef] [PubMed]
Nishimura, R. A. , Otto, C. M. , Bonow, R. O. , Carabello, B. A. , Erwin, J. P. , Guyton, R. A. , O'Gara, P. T. , Ruiz, C. E. , Skubas, N. J. , Sorajja, P. , Sundt, T. M. , and Thomas, J. D. , 2014, “ 2014 AHA/ACC Guideline for the Management of Patients With Valvular Heart Disease: Executive Summary: A Report of the American College of Cardiology/American Heart Association Task Force on Practice Guidelines,” J. Am. Coll. Cardiol., 63(22), pp. 2438–2488. [CrossRef] [PubMed]
Cao, K. , BukaČ, M. , and Sucosky, P. , 2016, “ Three-Dimensional Macro-Scale Assessment of Regional and Temporal Wall Shear Stress Characteristics on Aortic Valve Leaflets,” Comput. Methods Biomech. Biomed. Eng., 19(6), pp. 603–613. [CrossRef]
Dumont, K. , Vierendeels, J. , Kaminsky, R. , van Nooten, G. , Verdonck, P. , and Bluestein, D. , 2007, “ Comparison of the Hemodynamic and Thrombogenic Performance of Two Bileaflet Mechanical Heart Valves Using a CFD/FSI Model,” ASME J. Biomech. Eng., 129(4), pp. 558–565. [CrossRef]

Figures

Grahic Jump Location
Fig. 1

Parametric 3D numerical FE model of BAV type 1: (a) view from the aorta side, (b) side view of the root, (c) coronal plane view of the cusp and root, and (d) the model dimensions as a function of the annulus diameter (dAA)

Grahic Jump Location
Fig. 2

Four geometries of BAV type 1 with NFC angle (θNFC) varies from 120 deg to 180 deg

Grahic Jump Location
Fig. 3

(a) The collagen fiber alignment along the cusp. (b) True stress–strain curves for the hyper-elastic elastin and collagen in the cusp and the root. (c) The material constants suitable for employing the Ogden model with a first-order for the elastin and collagen, and a third-order for the sinuses. (d) The performed pressure in the dry model, calculated by the pressure difference in the aorta and left ventricle as a function of time.

Grahic Jump Location
Fig. 4

Maximum principal stress distribution on the four models during peak systole

Grahic Jump Location
Fig. 5

Maximum principal stress distribution on the four models during diastole (time 0.33 s)

Grahic Jump Location
Fig. 6

The jet flow velocity in the four BAV FSI models, during peak systole, presented in the A–A cross section (left)

Grahic Jump Location
Fig. 7

The FSS contours act on the deformed BAV configurations of the nonfused and fused cusps during peak systole in the FSI models

Tables

Errata

Discussions

Some tools below are only available to our subscribers or users with an online account.

Related Content

Customize your page view by dragging and repositioning the boxes below.

Related Journal Articles
Related eBook Content
Topic Collections

Sorry! You do not have access to this content. For assistance or to subscribe, please contact us:

  • TELEPHONE: 1-800-843-2763 (Toll-free in the USA)
  • EMAIL: asmedigitalcollection@asme.org
Sign In