Biaxial mechanical properties of bovine jugular venous valve leaflet tissues
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Venous valve incompetence has been implicated in diseases ranging from chronic venous insufficiency (CVI) to intracranial venous hypertension. However, while the mechanical properties of venous valve leaflet tissues are central to CVI biomechanics and mechanobiology, neither stress–strain curves nor tangent moduli have been reported. Here, equibiaxial tensile mechanical tests were conducted to assess the tangent modulus, strength and anisotropy of venous valve leaflet tissues from bovine jugular veins. Valvular tissues were stretched to 60% strain in both the circumferential and radial directions, and leaflet tissue stress–strain curves were generated for proximal and distal valves (i.e., valves closest and furthest from the right heart, respectively). Toward linking mechanical properties to leaflet microstructure and composition, Masson’s trichrome and Verhoeff–Van Gieson staining and collagen assays were conducted. Results showed: (1) Proximal bovine jugular vein venous valves tended to be bicuspid (i.e., have two leaflets), while distal valves tended to be tricuspid; (2) leaflet tissues from proximal valves exhibited approximately threefold higher peak tangent moduli in the circumferential direction than in the orthogonal radial direction (i.e., proximal valve leaflet tissues were anisotropic; \(p<0.01\)); (3) individual leaflets excised from the same valve apparatus appeared to exhibit different mechanical properties (i.e., intra-valve variability); and (4) leaflets from distal valves exhibited a trend of higher soluble collagen concentrations than proximal ones (i.e., inter-valve variability). To the best of the authors’ knowledge, this is the first study reporting biaxial mechanical properties of venous valve leaflet tissues. These results provide a baseline for studying venous valve incompetence at the tissue level and a quantitative basis for prosthetic venous valve design.
KeywordsAnisotropy Tissue biomechanics Biaxial testing Chronic venous insufficiency
The authors gratefully acknowledge Mr. George C. Engelmayr, Sr., for his assistance in sourcing bovine jugular vein tissues and Adam Benson for performing collagen assays on lyophilized valve tissues. This work was supported by NSF CBET-1553430.
Compliance with ethical standards
Conflict of interest
The authors declare that they have no conflict of interest.
- Bergan JJ (2008) Venous valve incompetence: the first culprit in the pathophysiology of chronic venous insufficiency. Medicographia 30:87–94Google Scholar
- Bernardini E, De Rango P, Piccioli R, Bisacci C, Pagliuca V, Genovese G, Bisacci R (2010) Development of primary superficial venous insufficiency: the ascending theory. Observational and hemodynamic data from a 9-year experience. Ann Vasc Surg 24:709–720. doi: 10.1016/j.avsg.2010.01.011 CrossRefGoogle Scholar
- Franklin K (1927) Valves in veins: an historical survey. Proc R Soc Med 21:1–33Google Scholar
- Franklin K (1929) Valves in veins: further observations. J Anat 64:67–69Google Scholar
- Hilbert SL, Sword LC, Batchelder KF, Barrick MK, Ferrans VJ (1996) Simultaneous assessment of bioprosthetic heart valve biomechanical properties and collagen crimp length. J Biomed Mater Res 31:503–509. doi: 10.1002/(Sici)1097-4636(199608)31:4<503::Aid-Jbm10>3.0.Co;2-H
- Kistner RL (1968) Surgical repair of a venous valve. Straub Clin Proc 34:41–43Google Scholar
- Moore HM, Gohel M, Davies AH (2011) Number and location of venous valves within the popliteal and femoral veins: a review of the literature. J Anat 219:439–443. doi: 10.1111/j.1469-7580.2011.01409.x
- Munger SJ, Geng X, Srinivasan RS, Witte MH, Paul DL, Simon AM (2016) Segregated Foxc2, NFATc1 and Connexin expression at normal developing venous valves, and Connexin-specific differences in the valve phenotypes of Cx37, Cx43, and Cx47 knockout mice. Dev Biol 412:173–190. doi: 10.1016/j.ydbio.2016.02.033 CrossRefGoogle Scholar
- Noishiki Y et al (1993) Development and evaluation of a pliable biological valved conduit. 1. Preparation, biochemical-properties, and histological-findings. Int J Artif Organs 16:192–198Google Scholar
- Sabine A et al (2012) Mechanotransduction, PROX1, and FOXC2 cooperate to control connexin37 and calcineurin during lymphatic-valve formation. Dev Cell 22:430–445. doi: 10.1016/j.devcel.2011.12.020
- Shen MR et al (2014) Biocompatibility evaluation of tissue-engineered valved venous conduit by reseeding autologous bone marrow-derived endothelial progenitor cells and multipotent adult progenitor cells into heterogeneous decellularized venous matrix. J Tissue Eng Regen Med. doi: 10.1002/term.1877 Google Scholar