Principles of Heart Valve Engineering

Cover
Principles of Heart Valve Engineering
Copyright
Dedication
Contributors
Preface
1 -
Clinical anatomy and embryology of heart valves
	1.1 Atrioventricular valves
		1.1.1 Embryology
		1.1.2 Morphology
		1.1.3 Histology
	1.2 Semilunar valves
		1.2.1 Embryology
		1.2.2 Morphology
		1.2.3 Histology
	1.3 Epigenetic factors in heart valve formation
	References
2 -
Heart valves\' mechanobiology
	2.1 Introduction
	2.2 Valvular interstitial cells
		2.2.1 Valvular interstitial cell phenotypes
		2.2.2 Influence of environmental mechanics
		2.2.3 Influence of sex and age
	2.3 Cell signaling and microenvironment
		2.3.1 Tumor necrosis factor alpha
		2.3.2 Transforming growth factor beta
		2.3.3 Nitric oxide
		2.3.4 Substrate composition
		2.3.5 Microenvironmental mechanics and geometry
	2.4 Role of extracellular matrix in heart valve biomechanics
	2.5 Extracellular matrix remodeling in heart valve disease
		2.5.1 Calcific aortic valve disease
		2.5.2 Mitral valve regurgitation
	2.6 Mechanobiology considerations for tissue engineering atrioventricular and semilunar valves
		2.6.1 Tissue engineered heart valve replacements
		2.6.2 Innovative in vitro models
	2.7 Future directions
	References
3 -
Epidemiology of heart valve disease
	3.1 Introduction
		3.1.1 Acute rheumatic fever as a precursor to rheumatic heart disease
	3.2 Epidemiology of heart valve disease in developed regions
		3.2.1 Aortic stenosis
		3.2.2 Aortic regurgitation
		3.2.3 Mitral stenosis
		3.2.4 Mitral regurgitation
		3.2.5 Right-sided valvular heart disease
		3.2.6 Infective endocarditis
	3.3 Epidemiology of heart valve disease in developing regions
	3.4 Epidemiology of congenital heart valve disease
	References
	Further reading
4 -
Surgical heart valves
	4.1 Introduction: history of surgical heart valves
	4.2 Mechanical valves
		4.2.1 Mechanical aortic valves
		4.2.2 Mitral position
		4.2.3 Other positions
		4.2.4 Need for anticoagulation
		4.2.5 Evaluation techniques
	4.3 Bioprosthetic valves
		4.3.1 Aortic bioprosthetic valves
			4.3.1.1 Porcine aortic xenografts
			4.3.1.2 Bovine pericardium
			4.3.1.3 Sutureless bioprostheses
			4.3.1.4 Outlook for bioprosthetic valves
		4.3.2 Other locations
			4.3.2.1 Mitral position
			4.3.2.2 Pulmonary position
			4.3.2.3 Tricuspid position
		4.3.3 Longevity issues for bioprosthetic valves
		4.3.4 Summary
	4.4 Prosthetic heart valve selection and development
	4.5 Unmet clinical needs and future areas of development
	References
5 -
Transcatheter heart valves
	5.1 History of transcatheter heart valves
	5.2 Transcatheter aortic valves
		5.2.1 Transfemoral approach
		5.2.2 Alternative access
		5.2.3 Valve design principles
		5.2.4 Long-term outcomes and durability concerns
		5.2.5 Delivery systems
	5.3 Transcatheter mitral valve repair and replacement
		5.3.1 Mitral valve apparatus function
		5.3.2 TMVR and TMVr technologies
			5.3.2.1 TMVr\'s leaflet technologies
			5.3.2.2 TMVr – chordal implantation
			5.3.2.3 TMVr – annuloplasty
			5.3.2.4 TMVr – ventricular reshaping
			5.3.2.5 TMVR systems
	5.4 Pediatric transcatheter heart valves
	References
6 -
Tissue-engineered heart valves
	6.1 Introduction
	6.2 The living heart valve—taking inspiration from nature
	6.3 Heart valve tissue engineering paradigms
		6.3.1 In vitro heart valve tissue engineering
		6.3.2 In situ heart valve tissue engineering
	6.4 The cellular players in heart valve tissue engineering
		6.4.1 Cell sources for in vitro heart valve tissue engineering
		6.4.2 In situ cellularization
	6.5 Scaffolds for heart valve tissue engineering
		6.5.1 Natural scaffolds
			6.5.1.1 Natural polymer–based hydrogels
			6.5.1.2 Extracellular matrix–based scaffolds
				6.5.1.2.1 Decellularized native tissues
				6.5.1.2.2 Decellularized tissue-engineered valves
		6.5.2 Synthetic scaffolds and hybrids
			6.5.2.1 Materials and functionalization
			6.5.2.2 Scaffold fabrication techniques
			6.5.2.3 Preseeded scaffolds
			6.5.2.4 Acellular resorbable scaffolds for in situ heart valve tissue engineering
		6.5.3 Scaffold-free approaches
	6.6 Bioreactors
		6.6.1 Whole-valve bioreactors for culturing and testing
		6.6.2 Real time noninvasive and nondestructive monitoring in bioreactors
	6.7 Computational modeling
		6.7.1 Predicting collagen remodeling in tissue-engineered heart valves
		6.7.2 Predicting growth through computational modeling
		6.7.3 Aiding physical design via computer modeling
	6.8 Minimally invasive delivery of tissue-engineered heart valves
	6.9 Perspective on current challenges for heart valve tissue engineering
		6.9.1 Inducing elastogenesis
		6.9.2 Harnessing the host response and tissue homeostasis
		6.9.3 Mechanistic approaches and stratification
	References
7 -
Computer modeling and simulation of heart valve function and intervention
	7.1 Introduction
	7.2 Governing equations
	7.3 Structural modeling
		7.3.1 Geometrical modeling
			7.3.1.1 Manual reconstruction of aortic valve geometries
			7.3.1.2 Automatic valve estimation from clinical cardiac images
			7.3.1.3 Importance of mesh correspondence in valve geometry reconstruction
		7.3.2 Tissue properties
			7.3.2.1 Experimental characterization of valve tissue properties
			7.3.2.2 Constitutive models of heart valve tissues
			7.3.2.3 Loading boundary conditions
		7.3.3 Computational structural analysis of heart valve function and intervention
			7.3.3.1 Modeling native aortic valves
			7.3.3.2 Modeling bioprosthetic heart valves
	7.4 Fluid–structure interaction
		7.4.1 FSI models of heart valve dynamics
		7.4.2 In vitro models
		7.4.3 Subject-specific models
	7.5 Conclusions and future outlook
	Acknowledgments
	References
8 -
In vitro experimental methods for assessment of prosthetic heart valves
	8.1 Hydrodynamic evaluation
		8.1.1 Steady flow testing
		8.1.2 Pulsatile flow systems
	8.2 Particle image velocimetry
	8.3 Accelerated wear testing
	8.4 Structural assessment
	8.5 Structural component fatigue assessment
	8.6 Corrosion assessment
	8.7 Summary
	References
9 -
Transvalvular flow
	9.1 Fluid dynamics of transmitral flow
		9.1.1 Transvalvular pressure drop
		9.1.2 Transmitral vortex formation
		9.1.3 Vortex formation time index
		9.1.4 Diastolic dysfunction and transmitral flow
		9.1.5 Mitral annulus recoil
		9.1.6 Consequences of mitral valve dysfunction
		9.1.7 Flow through the mechanical valves
	9.2 Fluid dynamics of the aortic valve
		9.2.1 Vortex formation in aortic sinus
		9.2.2 Bicuspid aortic valve disease
		9.2.3 Fluid dynamics of paravalvular leak
		9.2.4 Flow through the aortic protheses
	9.3 Fluid dynamics of the valves of the right heart
	References
10 -
Heart valve leaflet preparation
	10.1 Alternative fixation chemistries
	10.2 Anticalcification strategies
	10.3 No fixation
	10.4 Alpha-gal removal
	10.5 Different types of tissues
	10.6 Physical treatments
	10.7 Testing the efficacy of a tissue and its chemical treatments
	10.8 Stentless valves
	10.9 Surgeon factors
	10.10 Unmet needs and opportunities
	References
11 -
Heart valve calcification
	11.1 Native valves
		11.1.1 Aortic valve
		11.1.2 Mitral valve
	11.2 Bioprosthetic valves
		11.2.1 Surgical valve replacement
		11.2.2 Transcatheter intervention
	11.3 Structure and pathology of aortic valves
		11.3.1 Aortic valve anatomy
		11.3.2 Biomechanical environment
		11.3.3 CAVD pathology
		11.3.4 CAVD mechanism
		11.3.5 Hyperlipidemia models
		11.3.6 Lipoprotein(a)
		11.3.7 Inflammation
		11.3.8 Molecular regulators
		11.3.9 Bone morphogenetic protein-2
		11.3.10 Notch 1
		11.3.11 Autotaxin
		11.3.12 Serotonin (5-hydroxytryptamine)
		11.3.13 Von Willebrand factor
		11.3.14 Cyclooxygenase activity
		11.3.15 Wnt
		11.3.16 Other factors
	References
12 -
Immunological considerations for heart valve replacements
	12.1 Introduction
	12.2 Heart valve transplants
	12.3 Mechanical heart valves
	12.4 Tissue valves
		12.4.1 Bioprosthetic heart valves
		12.4.2 Tissue-engineered heart valves
	12.5 Transcatheter valves
	12.6 Conclusions and future directions
	References
13 -
Polymeric heart valves
	13.1 Introduction
		13.1.1 Scope
		13.1.2 Need
	13.2 History of polymeric valves
	13.3 Design considerations and challenges
		13.3.1 Material
			13.3.1.1 Polysiloxanes
			13.3.1.2 Polytetrafluoroethylene (PTFE)/expanded PTFE
			13.3.1.3 Polyurethanes
			13.3.1.4 Polyvinyl alcohol
			13.3.1.5 Linear low-density polyethylene
			13.3.1.6 Poly(styrene-block-isobutylene-block-styrene)
		13.3.2 Surface modifications
			13.3.2.1 Geometry
			13.3.2.2 Manufacturing
		13.3.3 Dip casting
		13.3.4 Film fabrication
		13.3.5 Cavity and injection molding
		13.3.6 Three-dimensional printing
	13.4 Investigational valves
	13.5 Summary and conclusions
	References
14 -
Regulatory considerations
	14.1 The sins of the father
	14.2 The need for documented procedures
	14.3 Risk versus reward
	14.4 Risk management
	14.5 Objective performance criteria
	14.6 Making sausages
	14.7 Failure of preclinical models
	14.8 A case study
	14.9 Closing
	References
APPENDIX.
Bernoulli’s equation, significance, and limitations
	A.1 Introduction
	A.2 Derivation of the generalized Bernoulli equation
	A.3 Generalized form of the Bernoulli equation for cardiovascular biofluid dynamics
	A.4 Bernoulli equation and pressure drop calculation
	A.5 Approximation of the Bernoulli convective term
	A.6 Approximation of the Bernoulli viscose term
	A.7 Simplified versions of the Bernoulli equation
	A.8 Conclusion
	References
Index
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	Q
	R
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	X
	Z
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