Human cranial dura mater (CDM) allograft’s success as a repair biomaterial is partly due to its high mechanical strength, which facilitates its ability to form water-tight barriers and resist high in-vivo mechanical loads. Previous studies on CDM allograft mechanical behavior used large test specimens and concluded that the allograft was mechanically isotropic. However, we have quantified CDM microstructure using small angle light scattering (SALS) and found regions of well-aligned fibers displaying structural symmetry between the right and left halves (Jimenez et al., 1998). The high degree of fiber alignment in these regions suggests that they are mechanically anisotropic. However, identification of these regions using SALS requires irreversible tissue dehydration, which may affect mechanical properties. Instead, we utilized CDM structural symmetry to estimate the fiber architecture of one half of the CDM using computer graphics to flip the SALS fiber architecture map of the corresponding half about the plane of symmetry. Test specimens (20 mm × 4 mm) were selected parallel and perpendicular to the preferred fiber directions and subjected to uniaxial mechanical failure testing. CDM allografts were found to be locally anisotropic, having an ultimate tensile strength (UTS) parallel to the fibers of 12.76 ± 1.65 MPa, and perpendicular to the fibers of 5.21 ± 1.01 MPa (mean ± sem). These results indicate that uniaxial mechanical tests on large samples used in previous studies tended to mask the local anisotropic nature of the smaller constituent sections. The testing methods established in this study can be used in the evaluation of new CDM processing methods and post-implant allograft mechanical integrity.

1.
Campbell
J. B.
,
Basset
C. A. L.
, et al.,
1958
, “
Clinical Use of Freeze-Dried Human Dura Mater
,”
Journal of Neurosurgery
,
15
:
207
214
.
2.
Chuong
C. J.
,
Sacks
M. S.
, et al.,
1991
, “
On the Anisotropy of the Diaphragmatic Central Tendon
,”
Journal of Biomechanics
,
24
:
563
576
.
3.
Fiorica
J. V.
,
Roberts
W. S.
, et al.,
1991
, “
Femoral Vessel Coverage With Dura Mater After Inguinofemoral Lymphadenectomy
,”
Gynecologic Oncology
,
42
:
217
221
.
4.
Garrett
S.
,
Martin
M.
, et al.,
1990
, “
Treatment of Peridontal Furcation Defects
,”
J. Clin. Peridontol.
,
17
:
179
185
.
5.
Jimenez
M.
,
Sacks
M.
, et al.,
1998
, “
Quantification of the collagen fiber architecture of human cranial dura mater
,”
Journal of Anatomy
, Vol.
192
, pp.
99
106
.
6.
Kelami
A.
,
1971
, “
Lyophilized Human Dura as a Bladder Wall Substitute Experimental and Clinical Results
,”
The Journal of Urology
,
105
:
518
522
.
7.
Lehman
R. A. W.
,
Hayes
G. J.
, et al.,
1967
, “
The Use of Adhesive and Lyophilized Dura in the Treatment of Cerebrospinal Rhinorrhea
,”
Journal of Neurosurgery
,
26
:
92
95
.
8.
McGarvey
K. A.
,
Lee
J. M.
, et al.,
1984
, “
Mechanical Suitability of Glycerol-Preserved Human Dura Mater for Construction of Prosthetic Cardiac Valves
,”
Biomaterials
,
5
:
109
117
.
9.
Melvin, J. W., J. H. McElhaney, et al., 1970, “Development of a Mechanical Model of the Human Head—Determination of Tissue Properties and Synthetic Substitute Materials,” Proc. Fourteenth Stapp Car Crash Conference, Ann Arbor, Society of Automotive Engineers, Inc., Nov., 17(18): 221–240.
10.
Otan˜o, S. E., M. S. Sacks, et al., 1995, “Mechanical Behavior of Human Dura Mater,” Proc. 1995 Bioengineering Conference, 29: 329–330.
11.
Parker
R.
,
Randev
R.
, et al.,
1978
, “
Storage of Heart Valve Allografts in Glycerol Preserved With Subsequent Antibiotic Sterilisation
,”
Thorax
,
33
:
638
645
.
12.
Planche
C. L.
,
Fichelle
J. M.
, et al.,
1987
, “
Long-Term Evaluation of Five Biomaterials for Angioplastic Enlargement of the Pulmonary Artery in Young Dog Model
,”
Journal of Biomedical Materials Research
,
21
:
509
523
.
13.
Root
M.
,
Lockhart
J. L.
, et al.,
1992
, “
Long-Term Followup With the Use of Lyophilized Dura Mater for Abdominal Wall Closure in Children: Report of 3 Cases
,”
The Journal of Urology
,
148
:
858
860
.
14.
Royce
P. L.
,
Zimmern
P. E.
, et al.,
1988
, “
Patch Grafting the Renal Pelvis and Uretopelvic Junction
,”
Urol. Res.
, Vol.
16
(
1
), pp.
37
41
.
15.
Sacks
M. S.
, and
Chuong
C. J.
,
1992
, “
Characterization of Collagen Fiber Architecture in the Canine Central Tendon
,”
ASME JOURNAL OF BIOMECHANICAL ENGINEERING
,
114
:
183
190
.
16.
Sacks
M. S.
,
Smith
D. S.
, et al.,
1997
, “
A SALS device for planar connective tissue microstructural analysis
,”
Annals of Biomedical Engineering
,
25
(
4
):
678
689
.
17.
University of Miami, 1995, Tissue Bank Technical Manual for the Preparation of Dura Mater Allografts.
18.
Usher
F. C.
,
1958
, “
Use of Lyophilized Homografts of Dura Mater in Repair of Incisional Hernias
,”
A. M. A. Archives of Surgery
,
76
:
58
61
.
19.
van Noort
R.
,
Black
M. M.
, et al.,
1981
, “
A study of the uniaxial mechanical properties of human dura mater preserved in glycerol
,”
Biomaterials
,
2
:
41
45
.
20.
Wolfinbarger
L.
,
Zhang
Y.
, et al.,
1994
, “
Biomechanical Aspects on Rehydrated Freeze-Dried Human Allograft Dura Tissues
,”
Journal of Applied Biomaterials
,
5
:
265
270
.
21.
Zaner
D. J.
,
Yukna
R. A.
, et al.,
1989
, “
Human Freeze-Dried Dura Mater Allografts as a Periodontal Biological Bandage
,”
J. Periodontol.
,
60
,
617
623
.
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