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Ex vivo biomechanical behavior of abdominal aortic aneurysm: Assessment using a new mathematical model

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Abstract

Knowledge of the biomechanical behavior of abdominal aortic aneurysm (AAA) as compared to nonaneurysmal aorta may provide information on the natural history of this disease. We have performed uniaxial tensile testing of excised human aneurysmal and nonaneurysmal abdominal aortic specimens. A new mathematical model that conforms to the fibrous structure of the vascular tissue was used to quantify the measured elastic response. We determined for each specimen the yield σy and ultimate σu strengths, the separate contribution to total tissue stiffness by elastin (E E) and collagen (E C) fibers, and a collagen recruitment parameter (A), which is a measure of the tortuosity of the collagen fibers. There was no significant difference in any of these mechanical properties between longitudinal and circumferential AAA specimens, nor inE E andE C between longitudinally oriented aneurysmal and normal specimens.A, σy, and σu were all significantly higher for the normal than for the aneurysmal group:A=0.223±0.046versus A=0.091±0.009 (mean ± SEM;p<0.0005), σy versus σy (p<0.05), and σu versus σu (p<0.0005), respectively. Our findings suggest that the AAA tissue is isotropic with respect to these mechanical properties. The observed difference inA between aneurysmal and normal aorta may be due to the complete recruitment and loading of collagen fibers at lower extensions in the former. Our data indicate that AAA rupture may be related to a reduction in tensile strength and that the biomechanical properties of AAA should be considered in assessing the severity of an individual aneurysm.

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References

  1. Armentano, R. L., J. Levenson, J. G. Barra, E. I. C. Fischer, G. J. Breitbart, R. H. Pichel, and A. Simon. Assessment of elastin and collagen contribution to aortic elasticity in conscious dogs.Am. J. Physiol. 260:H1870-H1877, 1991.

    PubMed  CAS  Google Scholar 

  2. Baxter, B. T., V. A. Davis, D. J. Minion, Y. P. Wang, T. G. Lynch, and B. M. McManus. Abdominal aortic aneurysms are associated with altered matrix proteins of the nonaneurysmal aortic segments.J. Vasc. Surg. 19:797–802, 1994.

    PubMed  CAS  Google Scholar 

  3. Carew, T. E., R. N. Vaishnav, and D. J. Patel. Compressibility of the arterial wall.Circ. Res. 23:61–68, 1968.

    PubMed  CAS  Google Scholar 

  4. Clark, J. M., and S. Glagov. Transmural organization of the arterial media: The lamellar unit revisited.Atherosclerosis 5:19–34, 1985.

    CAS  Google Scholar 

  5. Cole, C. W. Highlights of an international workshop on abdominal aortic aneurysms.Can. Med. Assoc. J. 141:393–395, 1989.

    CAS  Google Scholar 

  6. Cox, R. H. Passive mechanics and connective tissue composition of canine arteries.Am. J. Physiol. 234:H533-H541, 1978.

    PubMed  CAS  Google Scholar 

  7. Cronenwett, J. L., S. K. Sargent, H. Wall, M. L. Hawkes, D. H. Freeman, B. J. Dain, J. K. Cure, D. B. Walsh, R. M. Zwolak, M. D. McDaniel, and J. R. Schneider. Variables that affect the expansion rate and outcome of small abdominal aortic aneurysms.J. Vasc. Surg. 11:260–268, 1990.

    Article  PubMed  CAS  Google Scholar 

  8. Darling, R. C., R. Carlene, R. N. Messina, D. C. Brewster, and L. W. Ottinger. Autopsy study of unoperated abdominal aortic aneurysms: The case for early resection.Circulation 56:161–164, 1977.

    Google Scholar 

  9. Dobrin, P. B., and R. Mrkvicka. Failure of elastin and collagen as possible critical connective tissue alterations underlying aneurysmal dilation.Cardiovasc. Surg. 2:484–488, 1994.

    PubMed  CAS  Google Scholar 

  10. Dobrin, P. B. Pathophysiology and pathogenesis of aortic aneurysms.Surg. Clin. N. Am. 69:687–703, 1989.

    PubMed  CAS  Google Scholar 

  11. Drangova, M., D. W. Holdsworth, C. J. Boyd, P. J. Dunmore, M. R. Roach, and A. Fenster. Elasticity and geometry measurements of vascular specimens using a high resolution laboratory CT scanner.Physiol. Meas. 14:277–290, 1993.

    Article  PubMed  CAS  Google Scholar 

  12. He, C. M., and M. R. Roach. The composition and mechanical properties of abdominal aortic aneurysms.J. Vasc. Surg. 20:6–13, 1994.

    PubMed  CAS  Google Scholar 

  13. Lanne, T., B. Sonesson, H. Bengtsson, and D. Gustafsson. Diameter and compliance in the male human abdominal aorta: Influence of age and aortic aneurysm.Eur. J. Vasc. Surg. 6:178–184, 1992.

    Article  PubMed  CAS  Google Scholar 

  14. Lehninger, A. L.Biochemistry, New York: Worth Publishers, 1975, 833 pp.

    Google Scholar 

  15. Limet, R., N. Sakalihasan, and A. Albert. Determination of the expansion rate and incidence of rupture of abdominal aortic aneurysm.J. Vasc. Surg. 14:540–548, 1991.

    Article  PubMed  CAS  Google Scholar 

  16. Macsweeny, S. T., G. Young, R.M. Greenhalgh, and J. T. Powell. Mechanical properties of the aneurysmal aorta.Br. J. Surg. 79:1281–1284, 1992.

    Article  Google Scholar 

  17. McGee, G. S., B. T. Baxter, V. P. Shively, R. Chisholm, W. J. McCarthy, W. R. Flinn, J. S. Yao, and W. H. Pearce. Aneurysm or occlusive disease factors determining the clinical course of atherosclerosis of the infrarenal aorta.Surgery 110:370–375, 1991.

    PubMed  CAS  Google Scholar 

  18. Menashi, S., J. S. Campa, R. M. Greenhalgh, and J. T. Powell. Collagen in abdominal aortic aneurysm: Typing, content, and degradation.J. Vasc. Surg. 6:578–582, 1987.

    Article  PubMed  CAS  Google Scholar 

  19. Ouriel, K., R. M. Green, C. Donayree, C. K. Shortell, J. Elliot, and J. A. DeWeese. An evaluation of new methods of expressing aortic aneurysm size: Relationship to rupture.J. Vasc. Surg. 15:12–20, 1992.

    Article  PubMed  CAS  Google Scholar 

  20. Park, J. B., and A. S. Hoffman. Interaction of collagen and smooth muscle cells in aortic biomechanics.Ann. Biomed. Eng. 6:176–171, 1978.

    Article  Google Scholar 

  21. Rizzo, R. J., W. J. McCarthy, S. N. Dixit, M. P. Lilly, V. P. Shively, W. R. Flinn, and J. S. Yao. Collagen types and matrix protein content in human abdominal aortic aneurysms.J. Vasc. Surg. 10:365–373, 1989.

    Article  PubMed  CAS  Google Scholar 

  22. Roach, M. R., and A. C. Burton. The reason for the shape of the distensibility curves of arteries.Can. J. Biochem. Physiol. 35:681–690, 1957.

    PubMed  CAS  Google Scholar 

  23. Samila, Z. J., and S. A. Carter. The effect of age on the unfolding of elastin lamellae and collagen fibers with stretch in human carotid arteries.Can. J. Physiol. Pharmacol. 59: 1050–1057, 1981.

    PubMed  CAS  Google Scholar 

  24. Sherebrin, M. H., J. E. Hegney, and M. R. Roach. Effect of age on the anisotropy of the descending human thoracic aorta determined by uniaxial tensile testing and digestion by NaOH under load.Can. J. Physiol. Pharmacol. 67:871–878, 1989.

    PubMed  CAS  Google Scholar 

  25. Sterpetti, A. V., R. D. Schultz, R. J. Feldhaus, S. E. Cheng, and D. J. Peetz. Factors influencing enlargement rate of small abdominal aortic aneurysms.J. Surg. Res. 43:211–219, 1987.

    Article  PubMed  CAS  Google Scholar 

  26. Sumner, D. S., D. E. Hokanson, and D. E. Strandness. Stress-strain characteristics and collagen-elastin content of abdominal aortic aneurysms.Surg. Gynecol. Obstet 130: 459–466, 1970.

    PubMed  CAS  Google Scholar 

  27. Vaishnav, R. N., J. T. Young, J. S. Janicki, and D. J. Patel. Nonlinear anisotropic elastic properties of the canine aorta.Biophys. J. 12:1008–1027, 1972.

    PubMed  CAS  Google Scholar 

  28. Vawter, D. L. Poisson's ratio and incompressibility.J. Biomech. Eng. 105:194–195, 1983.

    Article  PubMed  CAS  Google Scholar 

  29. Vito, R. P., and J. Hickey. The mechanical properties of soft tissues-II: The elastic response of arterial segments.J. Biomech. 13:951–957, 1980

    Article  PubMed  CAS  Google Scholar 

  30. Vorp, D. A., K. R. Rajagopal, P. J. Smolinski, and H. S. Borovetz. Identification of elastic properties of homogeneous orthotropic vascular segments in distention.J. Biomech. 28:501–512, 1995.

    Article  PubMed  CAS  Google Scholar 

  31. Wolf, Y. G., W. S. Thomas, F. J. Brennan, W. G. Goff, and E. F. Bernstein. Computer topography scanning findings associated with rapid expansion of abdominal aortic aneurysms.J. Vasc. Surg. 20:529–535, 1994.

    PubMed  CAS  Google Scholar 

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Authors and Affiliations

  1. Bioengineering Program, University of Pittsburgh, Pittsburgh, PA

    M. L. Raghavan & David A. Vorp Ph.D.

  2. Department of Surgery, University of Pittsburgh, Pittsburgh, PA

    M. L. Raghavan, Marshall W. Webster & David A. Vorp Ph.D.

  3. Department of Mechanical Engineering, University of Pittsburgh, Pittsburgh, PA

    David A. Vorp Ph.D.

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  1. M. L. Raghavan
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  2. Marshall W. Webster
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  3. David A. Vorp Ph.D.
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Raghavan, M.L., Webster, M.W. & Vorp, D.A. Ex vivo biomechanical behavior of abdominal aortic aneurysm: Assessment using a new mathematical model. Ann Biomed Eng 24, 573–582 (1996). https://doi.org/10.1007/BF02684226

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  • DOI: https://doi.org/10.1007/BF02684226

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