Research Papers

Histology and Biaxial Mechanical Behavior of Abdominal Aortic Aneurysm Tissue Samples

[+] Author and Article Information
Francesco Q. Pancheri

Department of Mechanical Engineering,
Tufts University,
Medford, MA 02155

Robert A. Peattie

Department of Surgery,
Tufts Medical Center,
Boston, MA 02111
e-mail: robert.peattie@tufts.edu

Nithin D. Reddy, Timothy D. Ouellette, Mark D. Iafrati

Department of Surgery,
Tufts Medical Center,
Boston, MA 02111

Touhid Ahamed, Wenjian Lin

Department of Civil and
Environmental Engineering,
Tufts University,
Medford, MA 02155

A. Luis Dorfmann

Department of Civil and
Environmental Engineering,
Tufts University,
Medford, MA 02155;
Department of Biomedical Engineering,
Tufts University,
Medford, MA 02155

1Corresponding author.

Manuscript received December 16, 2015; final manuscript received November 1, 2016; published online January 23, 2017. Assoc. Editor: Jonathan Vande Geest.

J Biomech Eng 139(3), 031002 (Jan 23, 2017) (12 pages) Paper No: BIO-15-1647; doi: 10.1115/1.4035261 History: Received December 16, 2015; Revised November 01, 2016

Abdominal aortic aneurysms (AAAs) represent permanent, localized dilations of the abdominal aorta that can be life-threatening if progressing to rupture. Evaluation of risk of rupture depends on understanding the mechanical behavior of patient AAA walls. In this project, a series of patient AAA wall tissue samples have been evaluated through a combined anamnestic, mechanical, and histopathologic approach. Mechanical properties of the samples have been characterized using a novel, strain-controlled, planar biaxial testing protocol emulating the in vivo deformation of the aorta. Histologically, the tissue ultrastructure was highly disrupted. All samples showed pronounced mechanical stiffening with stretch and were notably anisotropic, with greater stiffness in the circumferential than the axial direction. However, there were significant intrapatient variations in wall stiffness and stress. In biaxial tests in which the longitudinal stretch was held constant at 1.1 as the circumferential stretch was extended to 1.1, the maximum average circumferential stress was 330 ± 70 kPa, while the maximum average axial stress was 190 ± 30 kPa. A constitutive model considering the wall as anisotropic with two preferred directions fit the measured data well. No statistically significant differences in tissue mechanical properties were found based on patient gender, age, maximum bulge diameter, height, weight, body mass index, or smoking history. Although a larger patient cohort is merited to confirm these conclusions, the project provides new insight into the relationships between patient natural history, histopathology, and mechanical behavior that may be useful in the development of accurate methods for rupture risk evaluation.

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Ashton, H. A. , Buxton, M. J. , Day, N. E. , Kim, L. G. , Marteau, T. M. , Scott, R. A. , Thompson, S. G. , and Walker, N. M. , 2002, “ The Multicentre Aneurysm Screening Study (Mass) Into the Effect of Abdominal Aortic Aneurysm Screening on Mortality in Men: A Randomized Control Trial,” Lancet, 360, pp. 1531–1539. [CrossRef] [PubMed]
Lederle, F. A. , Johnson, G. R. , Wilson, S. E. , Ballard, D. J. , Jordan, W. D., Jr. , Blebea, J. , Littooy, F. N. , Freischlag, J. A. , Bandyk, D. , Rapp, J. H. , and Salam, A. A. , 2002, “ Veterans Affairs Cooperative Study, I. Rupture Rate of Large Abdominal Aortic Aneurysms in Patients Refusing or Unfit for Elective Repair,” J. Am. Med. Assoc., 287(22), pp. 2968–2972. [CrossRef]
Karkos, C. , Mukhodpadhyay, U. , Papakostas, I. , Ghosh, J. , Thomson, G. , and Hughes, R. , 2000, “ Abdominal Aortic Aneurysm: The Role of Clinical Examination and Opportunistic Detection,” Eur. J. Vasc. Endovasc. Surg., 19(3), pp. 299–303. [CrossRef] [PubMed]
Davis, M. , Harris, M. , and Earnshaw, J. J. , 2013, “ Implementation of the National Health Service Abdominal Aortic Aneurysm Screening Program in England,” J. Vasc. Surg., 57(5), pp. 1440–1445. [CrossRef] [PubMed]
Lederle, F. A. , 2009, “ The Natural History of Abdominal Aortic Aneurysm,” Acta Chir. Belg., 109(1), pp. 7–12. [CrossRef] [PubMed]
CDC, 2015, “ National Center for Health Statistics,” Centers for Disease Control and Prevention, Atlanta, GA, accessed, June 2015, www.cdc.gov/nchs/deaths.htm
Grootenboer, N. , Bosch, J. , Hendriks, J. M. , and van Sambeek, M. R. H. M. , 2009, “ Epidemiology, Aetiology, Risk of Rupture and Treatment of Abdominal Aortic Aneurysms: Does Sex Matter?,” Eur. J. Vasc. Endovasc. Surg., 38(3), pp. 278–284. [CrossRef] [PubMed]
Lederle, F. A. , Wilson, S. E. , Johnson, G. R. , Reinke, D. B. , Littooy, F. N. , Acher, C. W. , Ballard, D. J. , Messina, L. M. , Gordon, I. L. , Chute, E. P. , Krupski, W. C. , Busuttil, S. J. , Barone, G. W. , Sparks, S. , Graham, L. M. , Rapp, J. H. , Makaroun, M. S. , Moneta, G. L. , Cambria, R. A. , Makhoul, R. G. , Eton, D. , Ansel, H. J. , Freischlag, J. A. , and Bandyk, D. , 2002, “ Immediate Repair Compared With Surveillance of Small Abdominal Aortic Aneurysms,” N. Engl. J. Med., 346(19), pp. 1437–1444. [CrossRef] [PubMed]
Nevitt, M. P. , Ballard, D. J. , and Hallett, J. W. , 1989, “ Prognosis of Abdominal Aortic Aneurysms: A Population Based Study,” N. Engl. J. Med., 321(15), pp. 1009–1014. [CrossRef] [PubMed]
Thompson, S. , Brown, L. , Sweeting, M. , Bown, M. , Kim, L. , Glover, M. , Buxton, M. , and Powell, J. , 2013, “ Systematic Review and Meta-Analysis of the Growth and Rupture Rates of Small Abdominal Aortic Aneurysms: Implications for Surveillance Intervals and Their Cost-Effectiveness,” Health Technol. Assess., 17(41), pp. 1–118. [CrossRef] [PubMed]
Fillinger, M. F. , Raghavan, M. L. , Marra, S. P. , Cronenwett, J. L. , and Kennedy, F. E. , 2002, “ In Vivo Analysis of Mechanical Wall Stress and Abdominal Aortic Aneurysm Rupture Risk,” J. Vasc. Surg., 36(3), pp. 589–597. [CrossRef] [PubMed]
Fillinger, M. F. , 2007, “ Who Should We Operate on and How Do We Decide: Predicting Rupture and Survival in Patients With Aortic Aneurysm,” Semin. Vasc. Surg., 20(2), pp. 121–127. [CrossRef] [PubMed]
Larsson, E. , Labruto, F. , Gasser, T. , Swedenborg, J. , and Hultgren, R. , 2011, “ Analysis of Aortic Wall Stress and Rupture Risk in Patients With Abdominal Aortic Aneurysm With a Gender Perspective,” J. Vasc. Surg., 54(2), pp. 295–299. [CrossRef] [PubMed]
Tong, J. , Cohnert, T. , Regitnig, P. , and Holzapfel, G. A. , 2011, “ Effects of Age on the Elastic Properties of the Intraluminal Thrombus and the Thrombus-Covered Wall in Abdominal Aortic Aneurysms: Biaxial Extension Behaviour and Material Modelling,” Eur. J. Vasc. Endovasc. Surg., 42(2), pp. 207–219. [CrossRef] [PubMed]
Dorfmann, A. , Wilson, C. , Edgar, E. S. , and Peattie, R. A. , 2010, “ Evaluating Patient-Specific Abdominal Aortic Aneurysm Wall Stress Based on Flow-Induced Loading,” Biomech. Model. Mechanobiol., 9(2), pp. 127–139. [CrossRef] [PubMed]
Ahamed, T. , Dorfmann, L. , and Ogden, R. W. , 2016, “ Modelling of Residually Stressed Materials With Application to AAA,” J. Mech. Behav. Biomed. Mater., 61, pp. 221–234. [CrossRef] [PubMed]
Campa, J. S. , Greenhalgh, R. M. , and Powell, J. T. , 1987, “ Elastin Degradation in Abdominal Aortic Aneurysms,” Atherosclerosis, 65, pp. 12–21. [CrossRef]
Choke, E. , Cockerill, G. , Wilson, W. R. W. , Sayed, S. , Dawson, J. , Loftus, I. , and Thompson, M. M. , 2005, “ A Review of Biological Factors Implicated in Abdominal Aortic Aneurysm Rupture,” Eur. J. Vasc. Endovasc. Surg., 30(3), pp. 227–244. [CrossRef] [PubMed]
He, C. M. , and Roach, M. R. , 1994, “ The Composition and Mechanical Properties of Abdominal Aortic Aneurysm,” J. Vasc. Surg., 20(1), pp. 6–13. [CrossRef] [PubMed]
Summer, D. S. , Hokanson, D. S. , and Strandness, D. E. J. , 1970, “ Stress Strain Characteristics and Collagen Elastin Content of Abdominal Aortic Aneurysms,” Surg. Gynecol. Obstet., 130(3), pp. 459–466. [PubMed]
McGee, G. S. , Baxter, B. T. , Shively, V. P. , Chisholm, R. , McCarthy, W. J. , Flinn, W. R. , Yao, J. S. T. , and Pearce, W. H. , 1991, “ Aneurysm or Occlusive Disease-Factors Determining the Clinical Course of Atherosclerosis of the Infrarenal Aorta,” Surgery, 110(2), pp. 370–376. https://www.ncbi.nlm.nih.gov/pubmed/1858045 [PubMed]
Vorp, D. A. , 2007, “ Biomechanics of Abdominal Aortic Aneurysm,” J. Biomech., 40(9), pp. 1887–1902. [CrossRef] [PubMed]
Maier, A. , Gee, M. W. , Reeps, C. , Eckstein, H. H. , and Wall, W. A. , 2010, “ Impact of Calcifications on Patient-Specific Wall Stress Analysis of Abdominal Aortic Aneurysms,” Biomech. Model. Mechanobiol., 9(5), pp. 511–521. [CrossRef] [PubMed]
Buijs, R. V. , Willems, T. P. , Tio, R. A. , Boersma, H. H. , Tielliu, I. F. , Slart, R. H. , and Zeebregts, C. J. , 2013, “ Calcification as a Risk Factor for Rupture of Abdominal Aortic Aneurysm,” Eur. J. Vasc. Endovasc. Surg., 46(5), pp. 542–548. [CrossRef] [PubMed]
Vande Geest, J. P. , Sacks, M. S. , and Vorp, D. A. , 2006, “ The Effects of Aneurysm on the Biaxial Mechanical Behavior of Human Abdominal Aorta,” J. Biomech., 39(7), pp. 1324–1334. [CrossRef] [PubMed]
Tong, J. , Schriefl, A. J. , Cohnert, T. , and Holzapfel, G. A. , 2013, “ Gender Differences in Biomechanical Properties, Thrombus Age, Mass Fraction and Clinical Factors of Abdominal Aortic Aneurysms,” Eur. J. Vasc. Endovasc. Surg., 45(4), pp. 364–372. [CrossRef] [PubMed]
O'Leary, S. A. , Healey, D. A. , Kavanagh, E. G. , Walsh, M. T. , McGloughlin, T. M. , and Doyle, B. J. , 2014, “ The Biaxial Biomechanical Behavior of Abdominal Aortic Aneurysm Tissue,” Ann. Biomed. Eng., 42(12), pp. 2440–2450. [CrossRef] [PubMed]
Holzapfel, G. A. , Sommer, G. , and Regitnig, P. , 2004, “ Anisotropic Mechanical Properties of Tissue Components in Human Atherosclerotic Plaques,” ASME J. Biomech. Eng., 126(5), pp. 657–665. [CrossRef]
Abu-Farha, F. , Hector, L. G., Jr. , and Khraisheh, M. , 2009, “ Cruciform-Shaped Specimens for Elevated Temperature Biaxial Testing of Lightweight Materials,” J.O.M., 61(8), pp. 48–56.
Waldman, S. D. , and Lee, J. M. , 2005, “ Effect of Sample Geometry on the Apparent Biaxial Mechanical Behaviour of Planar Connective Tissues,” Biomaterials, 26(35), pp. 7504–7513. [CrossRef] [PubMed]
Pancheri, F. P. , and Dorfmann, A. , 2014, “ Strain Controlled Biaxial Tension of Natural Rubber: New Experimental Data,” Rubber Chem. Technol., 87(1), pp. 120–138. [CrossRef]
Hansen, F. , Bergqvist, D. , Mangell, P. , Rydén, A. , Sonesson, B. , and Länne, T. , 1993, “ Non-Invasive Measurement of Pulsatile Vessel Diameter Change and Elastic Properties Human Arteries: A Methodological Study,” Clin. Physiol., 13(6), pp. 631–643. [CrossRef] [PubMed]
Länne, T. , Stale, H. , Bengtsson, H. , Gustafsson, D. , Bergqvist, D. , Sonesson, B. , Lecerof, H. , and Dahl, P. , 1992, “ Noninvasive Measurement of Diameter Changes in the Distal Abdominal Aorta in Man,” Ultrasound Med. Biol., 18(5), pp. 451–457. [CrossRef] [PubMed]
ABAQUS, Inc., 2013, “ Abaqus, Theory Manual,” Dassault Systèmes Simulia, Waltham, MA, Version 6.13.
Demiray, H. , 1972, “ A Note on the Elasticity of Soft Biological Tissues,” J. Biomech., 5(3), pp. 309–311. [CrossRef] [PubMed]
Holzapfel, G. A. , Gasser, T. C. , and Ogden, R. W. , 2000, “ A New Constitutive Framework for Arterial Wall Mechanics and a Comparative Study of Material Models,” J. Elasticity, 61, pp. 1–48. [CrossRef]
Ogden, R. W. , 1997, Non-Linear Elastic Deformations, Dover Publications, New York.
Pancheri, F. Q. , Eng, C. M. , Lieberman, D. E. , Biewener, A. A. , and Dorfmann, L. , 2014, “ A Constitutive Description of the Anisotropic Response of the Fascia Lata,” J. Mech. Behav. Biomed., 30, pp. 306–323. [CrossRef]
Pancheri, F. Q. , Eng, C. M. , Lieberman, D. E. , Biewener, A. A. , and Dorfmann, L. , 2015, “ Corrigendum to: A Constitutive Description of the Anisotropic Response of the Fascia Lata,” J. Mech. Behav. Biomed., 50, pp. 308–310. [CrossRef]
Buzzi-Ferraris, G. , and Manenti, F. , 2009, “ Kinetic Models Analysis,” Chem. Eng. Sci., 64(5), pp. 1061–1074. [CrossRef]
Junqueira, L. C. , and Carneiro, J. , 2005, Basic Histology: Text & Atlas, 11th ed., McGraw-Hill Lange, New York.
Baxter, B. T. , Terrin, M. C. , and Dalman, R. L. , 2008, “ Medical Management of Small Abdominal Aortic Aneurysms,” Circulation, 117(14), pp. 1883–1889. [CrossRef] [PubMed]
Wilmink, T. B. M. , Quick, C. R. G. , and Day, N. E. , 1999, “ The Association Between Cigarette Smoking and Abdominal Aortic Aneurysms,” J. Vasc. Surg., 30(6), pp. 1099–1105. [CrossRef] [PubMed]
Nagy, R. , Csobay-Novák, C. , Lovas, A. , Sótonyi, P. , and Bojtár, I. , 2015, “ Non-Invasive in vivo Time-Dependent Strain Measurement Method in Human Abdominal Aortic Aneurysms: Towards a Novel Approach to Rupture Risk Estimation,” J. Biomech., 48(10), pp. 1876–1886. [CrossRef] [PubMed]
Polzer, S. , Gasser, T. C. , Bursa, J. , Staffa, R. , Vlachovsky, R. , Man, V. , and Skacel, P. , 2013, “ Importance of Material Model in Wall Stress Prediction in Abdominal Aortic Aneurysms,” Med. Eng. Phys., 35(9), pp. 1282–1289. [CrossRef] [PubMed]
Gasser, T. D. , Gallinetti, S. , Xing, X. , Forsell, C. , Swedenborg, J. , and Roy, J. , 2012, “ Spatial Orientation of Collagen Fibers in the Abdominal Aortic Aneurysm's Wall and Its Relation to Wall Mechanics,” Acta Biomater., 8(8), pp. 3091–3103. [CrossRef] [PubMed]
Schulze-Bauer, C. A. J. , Morth, C. , and Holzapfel, G. A. , 2003, “ Passive Biaxial Mechanical Response of Aged Human Iliac Arteries,” ASME J. Biomech. Eng., 125(3), pp. 395–406. [CrossRef]
Sommer, G. , Regitnig, P. , Koeltringer, L. , and Holzapfel, G. A. , 2010, “ Biaxial Mechanical Properties of Intact and Layer-Dissected Human Carotid Arteries at Physiological and Supraphysiological Loadings,” Am. J. Physiol.-Heart C, 298(3), pp. H898–H912. [CrossRef]
Sommer, G. , and Holzapfel, G. A. , 2012, “ 3D Constitutive Modeling of the Biaxial Mechanical Response of Intact and Layer-Dissected Human Carotid Arteries,” J. Mech. Behav. Biomed. Mater., 5(1), pp. 116–128. [CrossRef] [PubMed]
Reeps, C. , Maier, A. , Pelisek, J. , Härtl, F. , Grabher-Meier, V. , Wall, W. A. , Essler, M. , Eckstein, H. H. , and Gee, M. W. , 2013, “ Measuring and Modeling Patient-Specific Distributions of Material Properties in Abdominal Aortic Aneurysm Wall,” Biomech. Model. Mechanobiol., 12(4), pp. 717–733. [CrossRef] [PubMed]
Ogden, R. W. , Saccomandi, G. , and Sgura, I. , 2004, “ Fitting Hyperelastic Models to Experimental Data,” Comput. Mech., 34(6), pp. 484–502. [CrossRef]
Lindeman, J. H. N. , Ashcroft, B. A. , Beenakker, J. W. M. , van Es, M. , Koekkoek, N. B. R. , Prins, F. A. , Tielemans, J. F. , Abdul-Hussien, H. , Bank, R. A. , and Oosterkamp, T. H. , 2010, “ Distinct Defects in Collagen Microarchitecture Underlie Vessel-Wall Failure in Advanced Abdominal Aneurysms and Aneurysms in Marfan Syndrome,” Proc. Natl. Acad. Sci., 107(2), pp. 862–865. [CrossRef]
Wilson, K. , Lindholt, J. , Hoskins, P. , Heickendorff, L. , Vammen, S. , and Bradbury, A. , 2001, “ The Relationship Between Abdominal Aortic Aneurysm Distensibility and Serum Markers of Elastin and Collagen Metabolism,” Eur. J. Vasc. Endovasc. Surg., 21(2), pp. 175–178. [CrossRef] [PubMed]
Erhart, P. , Grond-Ginsbach, C. , Hakimi, M. , Lasitschka, F. , Dihlmann, S. , Böckler, D. , and Alexander Hyhlik-Dürr, A. , 2014, “ Finite Element Analysis of Abdominal Aortic Aneurysms: Predicted Rupture Risk Correlates With Aortic Wall Histology in Individual Patients,” J. Endovasc. Ther., 21(4), pp. 556–564. [CrossRef] [PubMed]
Rissland, P. , Alemu, Y. , Einav, S. , Ricotta, J. , and Bluestein, D. , 2009, “ Abdominal Aortic Aneurysm Risk of Rupture: Patient-Specific FSI Simulations Using Anisotropic Model,” ASME J. Biomech. Eng., 131(3), p. 031001. [CrossRef]
Raut, S. S. , Jana, A. , De Oliveira, V. , Muluk, S. C. , and Finol, E. A. , 2013, “ The Importance of Patient-Specific Regionally Varying Wall Thickness in Abdominal Aortic Aneurysm Biomechanics,” ASME J. Biomech. Eng., 135(8), p. 81010. [CrossRef]
Tierney, A. P. , Callanan, A. , and McGloughlin, T. M. , 2012, “ Use of Regional Mechanical Properties of Abdominal Aortic Aneurysms to Advance Finite Element Modeling of Rupture Risk,” J. Endovasc. Ther., 19(1), pp. 100–114. [CrossRef] [PubMed]
Polzer, S. , and Gasser, T. C. , 2015, “ Biomechanical Rupture Risk Assessment of Abdominal Aortic Aneurysm Based on a Novel Probabilistic Rupture Risk Index,” J. R. Soc. Interface, 12(113), p. 20150852. [CrossRef] [PubMed]
Imura, T. , Yamamoto, K. , Kanamori, K. , Mikami, T. , and Yasuda, H. , 1986, “ Non-Invasive Ultrasonic Measurement of the Elastic Properties of the Human Abdominal Aorta,” Cardiovasc. Res., 20(3), pp. 208–214. [CrossRef] [PubMed]
Tavares Monteiro, J. , Simão da Silva, E. , Raghavan, M. , Puech-Leão, P. , Higuchi, M. , and Otoch, J. , 2013, “ Histologic, Histochemical, and Biomechanical Properties of Fragments Isolated From the Anterior Wall of Abdominal Aortic Aneurysms,” J. Vasc. Surg., 59, pp. 1393–1401. [CrossRef] [PubMed]
Vande Geest, J. P. , Wang, D. H. J. , Wisniewski, S. R. , Makaroun, M. S. , and Vorp, D. A. , 2006, “ Towards a Noninvasive Method for Determination of Patient-Specific Wall Strength Distribution in Abdominal Aortic Aneurysms,” Ann. Biomed. Eng., 34(7), pp. 1098–1106. [CrossRef] [PubMed]
Buijs, R. V. , Willems, T. P. , Tio, R. A. , Boersma, H. H. , Tielliu, I. F. , Slart, R. H. , and Zeebregts, C. J. , 2013, “ Calcification as a Risk Factor for Rupture of Abdominal Aortic Aneurysm,” Eur. J. Vasc. Endovasc. Surg., 46(5), pp. 542–548. [CrossRef] [PubMed]


Grahic Jump Location
Fig. 2

Finite element calculation. (a) Mesh used to evaluate the deformation field in the gage region of the cruciform-shaped sample, with length scale. (b)–(d) Contour plots showing homogeneity of the deformation field, (b) axial stretch distribution, (c) circumferential stretch distribution, and (d) shear distribution.

Grahic Jump Location
Fig. 1

(a) AAA tissue sample as received. Severe polymorphous atherosclerotic plaque with precipitated calcium agglomerates is clearly apparent. (b) Tissue specimen undergoing planar biaxial tension. Digital gage marks track the movement of the physical markers. The circumferential and longitudinal directions of the sample relative to the aorta are shown on the right. (c) Schematic diagram of the biaxial test apparatus, showing the sample, water bath, grips, actuator arms, and load cells. Not shown is the video extensometer directly above the specimen used to measure and control deformation in the gage region.

Grahic Jump Location
Fig. 4

Measured nominal stress components in the circumferential and axial directions, Pθθ and Pzz, for patient 2 during the fifth loading cycle in each test. (a) λz = 1.0, λθ → 1.1, (b) λz = 1.1, λθ → 1.1, (c) λz → 1.1, λθ → 1.1, and (d) λz = 1.0, λθ → 1.15.

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Fig. 3

Representative histologic images characterizing the wall ultrastructure, 40× magnification, Masson's trichrome stain. Blue—collagen; red—smooth muscle and extravasated cells. All images oriented with the tunica intima facing down. (a) Patient 2, (b) patient 4, (c) patient 5, (d) patient 6, and (e) patient 7. (f) Fractional area of coverage for EvG (highlighting elastin fibers), TRI (highlighting collagen fibers), or anti-SMA (highlighting smooth muscle). dM—disrupted tunica media and dA—disrupted tunica adventitia.

Grahic Jump Location
Fig. 5

Measured nominal stress components in the circumferential and axial directions, Pθθ and Pzz, during the fifth loading cycle in each test, averaged over all patient samples. (a) λz = 1.0, λθ → 1.1, (b) λz = 1.1, λθ → 1.1, (c) λz → 1.1, λθ → 1.1, and (d) λz = 1.0, λθ → 1.15. Data points—measured values; solid curves—corresponding model fitted curves.

Grahic Jump Location
Fig. 6

(a) Values of mean maximum stresses and (b) of mean maximum elastic moduli in equibiaxial tension in the circumferential, (θ), and longitudinal, (z), directions

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Fig. 7

Representative failure sites of tissue samples failing during biaxial extension tests. Axial arrow indicates the original axial orientation of the tissue sample in the AAA wall. Red arrow indicates the site and orientation of failure. (a) Patient 3, (b) patient 4, (c) patient 5, and (d) patient 6.



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