Idiopathic onset of unilateral vocal fold paralysis (UVP) is caused by damage to the recurrent laryngeal nerve (RLN) and results in difficulty speaking, breathing, and swallowing. This damage may occur in this nerve as it loops around the aortic arch, which is in a dynamic biomechanical environment. The goal of this study is to determine if the location-dependent biomechanical and microstructural properties of the RLN are different in piglets versus adolescent pigs. The neck/distal and thoracic/proximal (near the aortic arch) regions of the RLN from eight adolescent pigs and six piglets were isolated and mechanically assessed in uni-axial tension. Two-photon imaging (second harmonic) data were collected at 5%, 10%, and 15% strain during the mechanical test. The tangential modulus (TM) and the strain energy density (W) were determined at each level of strain. The mean mode of the preferred fiber angle and the full width at half maximum (FWHM, a measure of fiber splay) were calculated from the imaging data. We found significantly larger values of TM, W, and FWHM in the proximal segments of the left RLN when compared to the distal segments (18.51 MPa ± 1.22 versus 10.78 MPa ± 1.22, p < 0.001 for TM, 0.046 MPa ± 0.01 versus 0.026 MPa ± 0.01, p < 0.003 for W, 15.52 deg ± 1.00 versus 12.98 deg ± 1.00, p < 0.001 for FWHM). TM and W were larger in the left segments than the right (15.32 MPa ± 1.20 versus 11.80 MPa ± 1.20, p < 0.002 for TM, 0.038 MPa ± 0.01 versus 0.028 MPa ± 0.01, p < 0.0001 for W). W was larger in piglets when compared to adolescent pigs (0.042 MPa ± 0.01 versus 0.025 MPa ± 0.01, p < 0.04). The proximal region of the left porcine RLN is more stiff than the distal region and has a higher degree of fiber splay. The left RLN of the adolescent pigs also displayed a higher degree of strain stiffening than the right. These differences may develop as a result of the more dynamic environment the left RLN is in as it loops around the aortic arch.

References

References
1.
Heitmiller
,
R. F.
,
Tseng
,
E.
, and
Jones
,
B.
,
2007
, “
Prevalence of Aspiration and Laryngeal Penetration in Patients With Unilateral Vocal Fold Motion Impairment
,”
Dysphagia
,
15
(
4
), pp.
184
187
.10.1007/s004550000026
2.
Dedo
,
H. H.
,
1970
, “
The Paralyzed Larynx: An Electromyographic Study in Dogs and Humans
,”
Laryngoscope
,
80
(
10
), pp.
1455
1517
.10.1288/00005537-197010000-00001
3.
Duncan
,
I. D.
,
Griffiths
,
I. R.
,
McQueen
,
A.
, and
Baker
,
G. O.
,
1974
, “
The Pathology of Equine Laryngeal Hemiplegia
,”
Acta Neuropathol.
,
27
(
4
), pp.
337
348
.10.1007/BF00690698
4.
Hillstrom
,
R. P.
,
Cohn
,
A. M.
, and
McCarroll
,
K. A.
,
1990
, “
Vocal Cord Paralysis Resulting From Neck Injections in the Intravenous Drug Use Population
,”
Laryngoscope
,
100
(
5
), pp.
503
506
.10.1288/00005537-199005000-00012
5.
Rosin
,
D. F.
,
Handler
,
S. D.
,
Potsic
,
W. P.
,
Wetmore
,
R. F.
, and
Tom
,
L. W. C.
,
1990
, “
Vocal Cord Paralysis in Children
,”
Laryngoscope
,
100
(
11
), pp.
1174
1179
.10.1288/00005537-199011000-00008
6.
Ward
,
P. H.
, and
Berci
,
G.
,
1982
, “
Observations on So-Called Idiopathic Vocal Cord Paralysis
,”
Ann. Otol., Rhinol., Laryngol.
,
91
(
6 Pt 1
), pp.
558
563
.
7.
Haller
,
J. M.
,
Iwanik
,
M.
, and
Shen
,
F. H.
,
2012
, “
Clinically Relevant Anatomy of Recurrent Laryngeal Nerve
,”
Spine
,
37
(
2
), pp.
97
100
.10.1097/BRS.0b013e31821f3e86
8.
Kelchner
,
L. N.
,
Stemple
,
J. C.
,
Gerdeman
,
E.
,
Le Borgne
,
W.
, and
Adam
,
S.
,
1999
, “
Etiology, Pathophysiology, Treatment Choices, and Voice Results for Unilateral Adductor Vocal Fold Paralysis: A 3-Year Retrospective
,”
J. Voice
,
13
(
4
), pp.
592
601
.10.1016/S0892-1997(99)80013-7
9.
Mu
,
L.
, and
Yang
,
S.
,
1991
, “
An Experimental Study on the Laryngeal Electromyography and Visual Observations in Varying Types of Surgical Injuries to the Unilateral Recurrent Laryngeal Nerve in the Neck
,”
Laryngoscope
,
101
(
7 Pt 1
), pp.
699
708
.10.1288/00005537-199107000-00003
10.
Quiney
,
R. E.
, and
Michaels
,
L.
,
1990
, “
Histopathology of Vocal Cord Palsy From Recurrent Laryngeal Nerve Damage
,”
J. Otolaryngol.
,
19
(
4
), pp.
237
241
.
11.
Sannella
,
N. A.
,
Tober
,
R. L.
,
Cipro
,
R. P.
,
Pedicino
,
J. F.
,
Donovan
,
E.
, and
Gabriel
,
N.
,
1990
, “
Vocal Cord Paralysis Following Carotid Endarterectomy: The Paradox of Return of Function
,”
Ann. Vasc. Surg.
,
4
(
1
), pp.
42
45
.10.1007/BF02042688
12.
Teixido
,
M. T.
, and
Leonetti
,
J. P.
,
1990
, “
Recurrent Laryngeal Nerve Paralysis Associated With Thoracic Aortic Aneurysm
,”
Otolaryngol., Head Neck Surg.
,
102
(
2
), pp.
140
144
.
13.
Cunning
,
D. S.
,
1955
, “
Unilateral Vocal Cord Paralysis
,”
Ann. Otol., Rhinol., Laryngol.
,
64
(
2
), pp.
487
493
.
14.
Huppler
,
E. G.
,
Schmidt
,
H. W.
,
Devine
,
D.
, and
Gage
,
R. P.
,
1955
, “Causes of Vocal-Cord Paralysis,”
Proc. Staff Meet. Mayo Clin.
,
30
(22), pp. 518–521.
15.
Sulica
,
L.
,
2008
, “
The Natural History of Idiopathic Unilateral Vocal Fold Paralysis: Evidence and Problems
,”
Laryngoscope
,
118
(
7
), pp.
1303
1307
.10.1097/MLG.0b013e31816f27ee
16.
Bando
,
H.
,
Nishio
,
T.
,
Bamba
,
H.
,
Uno
,
T.
, and
Hisa
,
Y.
,
2006
, “
Vocal Fold Paralysis as a Sign of Chest Diseases: A 15-Year Retrospective Study
,”
World J. Surg.
,
30
(
3
), pp.
293
298
.10.1007/s00268-005-7959-x
17.
Coscaron Blanco
,
E.
,
Blanco Garcia
,
J. L.
, and
Gomez Gonzalez
,
J. L.
,
2006
, “
An Uncommon Cause for Unilateral Vocal Fold Paralisis: Aortic Aneurysms. Case Report and Literature Review
,”
Otorrinolaringol. Ibero. Am.
,
33
(
5
), pp.
481
487
.
18.
Escribano
,
J. F.
,
Carnés
,
J.
,
Crespo
,
M. A.
, and
Antón
,
R. F.
,
2006
, “
Ortner's Syndrome and Endoluminal Treatment of a Thoracic Aortic Aneurysm: A Case Report
,”
Vasc. Endovasc. Surg.
,
40
(
1
), pp.
75
78
.10.1177/153857440604000111
19.
Wunderlich
,
C.
,
Wunderlich
,
O.
,
Tausche
,
A. K.
,
Fuhrmann
,
J.
,
Boscheri
,
A.
, and
Strasser
,
R. H.
,
2007
, “
Ortner's Syndrome or Cardiovocal Hoarseness
,”
Int. Med. J.
,
37
(
6
), pp.
418
419
.10.1111/j.1445-5994.2007.01341.x
20.
Lundborg
,
G.
,
1998
, “
Intraneural Microcirculation
,”
Orthop. Clin. North Am.
,
19
(
1
), pp.
1
12
.
21.
Peters
,
A.
,
Palay
,
S. L.
, and
Webster
,
H. D.
,
1991
,
The Fine Structure of the Nervous System: Neurons and Their Supporting Cells
,
3rd ed.
,
Oxford University Press
,
NY
,. p.
494
.
22.
Sunderland
,
S.
,
1965
The Connective Tissues of Peripheral Nerves
,”
Brain
,
88
(
4
), pp.
841
854
.10.1093/brain/88.4.841
23.
Sunderland
,
S.
,
1970
, “
Anatomical Features of Nerve Trunks in Relation to Nerve Injury and Nerve Repair
,”
Clin. Neurosurg.
,
17
, pp.
38
62
.
24.
Sunderland
,
S.
,
1978
,
Nerves and Nerve Injuries
,
2nd ed.
,
Churchill Livingstone; Longman
, Edinburgh, p.
1046
.
25.
Sunderland
,
S.
,
1990
, “
The Anatomy and Physiology of Nerve Injury
,”
Muscle Nerve
,
13
(
9
), pp.
771
784
.10.1002/mus.880130903
26.
Sunderland
,
S.
, and
Bradley
,
K. C.
,
1961
, “
Stress-Strain Phenomena in Denervated Peripheral Nerve Trunks
,”
Brain
,
84
, pp.
125
127
.10.1093/brain/84.1.125
27.
Sunderland
,
S.
, and
Bradley
,
K. C.
,
1961
, “
Stress-Strain Phenomena in Human Peripheral Nerve Truanks
,”
Brain
,
84
, pp.
102
119
.10.1093/brain/84.1.102
28.
Sunderland
,
S.
, and
Bradley
,
K. C.
,
1961
, “
Stress-Strain Phenomena in Human Spinal Nerve Roots
,”
Brain
,
84
, pp.
120
124
.10.1093/brain/84.1.120
29.
Thomas
,
P. K.
,
1963
, “
The Connective Tissue of Peripheral Nerve: An Electron Microscope Study
,”
J. Anat.
,
97
, pp.
35
44
.
30.
Ushiki
,
T.
, and
Ide
,
C.
,
1990
, “
Three-Dimensional Organization of the Collagen Fibrils in the Rat Sciatic Nerve as Revealed by Transmission- and Scanning Electron Microscopy
,”
Cell Tissue Res.
,
260
(
1
), pp.
175
184
.10.1007/BF00297503
31.
Haftek
,
J.
,
1970
, “
Stretch Injury of Peripheral Nerve. Acute Effects of Stretching on Rabbit Nerve
,”
J. Bone Jt. Surg. Br.
,
52
(
2
), pp.
354
365
.
32.
Rydevik
,
B. L.
,
Kwan
,
M. K.
,
Myers
,
R. R.
,
Brown
,
R. A.
,
Triggs
,
K. J.
,
Woo
,
S. L.
, and
Garfin
,
S. R.
,
1990
, “
An in Vitro Mechanical and Histological Study of Acute Stretching on Rabbit Tibial Nerve
,”
J. Orthop. Res.
,
8
(
5
), pp.
694
701
.10.1002/jor.1100080511
33.
Nicholson
,
K. J.
, and
Winkelstein
,
B. A.
,
2011
, “
Nerve and Nerve Root Biomechanics
,”
Neural Tissue Biomech.
,
3
, pp.
203
229
.10.1007/978-3-642-13890-4
34.
Sunderland
,
S.
, and
Bedbrook
,
G. M.
,
1949
, “
The Cross-Sectional Area of Peripheral Nerve Trunks Devoted to Nerve Fibres
,”
Brain
,
72
, pp.
428
449
.10.1093/brain/72.3.428
35.
Campbell
,
E. O.
,
Samlan
,
R. A.
,
McMullen
,
N. T.
,
Cook
,
S.
,
Smiley-Jewell
,
S.
, and
Barkmeier-Kraemer
,
J.
,
2013
, “
Developmental Changes in the Connective Tissues of the Porcine Recurrent Laryngeal Nerve
,”
J. Anat.
,
222
(
6
), pp.
625
633
.10.1111/joa.12046
36.
Alexander
,
M. J.
,
Barkmeier-Kraemer
,
J. M.
, and
Vande Geest
,
J. P.
,
2010
, “
Biomechanical Properties of Recurrent Laryngeal Nerve in the Piglet
,”
Ann. Biomed. Eng.
,
38
(
8
), pp.
2553
2562
.10.1007/s10439-010-0013-7
37.
Sunderland
,
S.
,
1945
, “
The Adipose Tissue of Peripheral Nerves
,”
Brain
,
68
, pp.
118
122
.10.1093/brain/68.2.118
38.
Sunderland
,
S.
,
1951
, “
A Classification of Peripheral Nerve Injuries Producing Loss of Function
,”
Brain
,
74
(
4
), pp.
491
516
.10.1093/brain/74.4.491
39.
Peti-Peterdi
,
J.
, and
Bell
,
P. D.
,
2003
, “
Confocal and Two-Photon Microscopy
,”
Methods Mol. Med.
,
86
, pp.
129
138
.10.1385/1-59259-392-5:129
40.
Kirkpatrick
,
N. D.
,
Hoying
,
J. B.
,
Botting
,
S. K.
,
Weiss
,
J. A.
, and
Utzinger
,
U.
,
2006
, “
In Vitro Model for Endogenous Optical Signatures of Collagen
,”
J. Biomed. Opt.
,
11
(
5
), p.
054021
.10.1117/1.2360516
41.
Raghavan
,
M. L.
, and
Vorp
,
D. A.
,
2000
, “
Toward a Biomechanical Tool to Evaluate Rupture Potential of Abdominal Aortic Aneurysm: Identification of a Finite Strain Constitutive Model and Evaluation of Its Applicability
,”
J. Biomech.
,
33
(
4
), pp.
475
482
.10.1016/S0021-9290(99)00201-8
42.
Borschel
,
G. H.
,
Kia
,
K. F.
,
Kuzon
,
W. M.
, Jr.
, and
Dennis
,
R. G.
,
2003
, “
Mechanical Properties of Acellular Peripheral Nerve
,”
J. Surg. Res.
,
114
(
2
), pp.
133
139
.10.1016/S0022-4804(03)00255-5
43.
Ma
,
Z.
,
Hu
,
S.
,
Tan
,
J. S.
,
Myer
,
C.
,
Njus
,
N. M.
, and
Xia
,
Z.
,
2013
, “
In Vitro and in Vivo Mechanical Properties of Human Ulnar and Median Nerves
,”
J. Biomed. Mater. Res. A
,
101
(
9
), pp.
2718
2725
.10.1002/jbm.a.34573
44.
Millesi
,
H.
,
Zoch
,
G.
, and
Reihsner
,
R.
,
1995
, “
Mechanical Properties of Peripheral Nerves
,”
Clin. Orthop. Relat. Res.
,
1995
(
314
), pp.
76
83
.
45.
Phillips
,
J. B.
,
Smit
,
X.
,
De Zoysa
,
N.
,
Afoke
,
A.
, and
Brown
,
R. A.
,
2004
, “
Peripheral Nerves in the Rat Exhibit Localized Heterogeneity of Tensile Properties During Limb Movement
,”
J. Physiol.
,
557
(
Pt 3
), pp.
879
887
.10.1113/jphysiol.2004.061804
46.
Rickett
,
T.
,
Connell
,
S.
,
Bastijanic
,
J.
,
Hegde
,
S.
, and
Shi
,
R.
,
2011
, “
Functional and Mechanical Evaluation of Nerve Stretch Injury
,”
J. Med. Syst.
,
35
(
5
), pp.
787
793
.10.1007/s10916-010-9468-1
47.
Topp
,
K. S.
, and
Boyd
,
B. S.
,
2006
, “
Structure and Biomechanics of Peripheral Nerves: Nerve Responses to Physical Stresses and Implications for Physical Therapist Practice
,”
Phys. Ther.
,
86
(
1
), pp.
92
109
.
48.
Wall
,
E. J.
,
Kwan
,
M. K.
,
Rydevik
,
B. L.
,
Woo
,
S. L.
, and
Garfin
,
S. R.
,
1991
, “
Stress Relaxation of a Peripheral Nerve
,”
J. Hand Surg. Am.
,
16
(
5
), pp.
859
863
.10.1016/S0363-5023(10)80149-2
49.
Wall
,
E. J.
,
Massie
,
J. B.
,
Kwan
,
M. K.
,
Rydevik
,
B. L.
,
Myers
,
R. R.
, and
Garfin
,
S. R.
,
1992
, “
Experimental Stretch Neuropathy. Changes in Nerve Conduction Under Tension
,”
J. Bone Jt. Surg. Br.
,
74
(
1
), pp.
126
129
.
50.
Deslauriers
,
J.
,
2007
, “
Anatomy of the Neck and Cervicothoracic Junction
,”
Thoracic Surg. Clin.
17
, pp.
529
547
.10.1016/j.thorsurg.2006.12.009
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