Vol 69, No 4 (2010)
Case report
Submitted: 2012-02-06
Published online: 2010-12-01
Transverse subisthmic course of the innominate artery in an adult: detailed anatomy and additional variation
M.C. Rusu, A.L. Boscu
Folia Morphol 2010;69(4):261-266.
Vol 69, No 4 (2010)
CASE REPORTS
Submitted: 2012-02-06
Published online: 2010-12-01
Abstract
A rare morphology of an aberrant innominate artery (IA) is reported here, together
with additional arterial variation encountered in the respective specimen.
The IA originated in the aortic arch on the left side of the trachea, coursed
on that side of the trachea to reach the left thyroid lobe, turned in at a right
angle to pass anterior to the trachea and immediately inferior and parallel to
the thyroid isthmus, and finally it divided inferior to the right thyroid lobe into
the right subclavian and common carotid arteries. The right common carotid
artery immediately turned at a right angle to ascend in the neck. Thus the
terminal branches of the IA had origins in a higher position than is usually
expected. This aberrant course of the IA determined a step-like morphology in
the sagittal plane of the left common carotid artery. Additional variations were
also encountered: (a) a lateralised right external carotid artery with the superior
thyroid artery initially coursing over the internal carotid artery; (b) the right
vertebral artery coursing over the inferior thyroid artery and entering the transverse
process of the fifth cervical vertebra; (c) the left subclavian and vertebral
arteries were tortuous. Knowledge of the presence of this IA variant, with
a transverse subisthmic segment, appears to be important in various surgical
approaches, such as tracheostomies, thyroidectomies, and mediastinoscopies;
in addition, the variations of the IA and the vertebral arteries are relevant for
lower cervical spine approaches. Nevertheless, the lateralised external carotid
artery may lead, if unidentified, to hemorrhagic complications during carotid
space approaches. It is important for surgeons to be aware that if an aberrant IA
is identified it may not be the only variation in that patient. (Folia Morphol 2010;
69, 4: 261-266)
Abstract
A rare morphology of an aberrant innominate artery (IA) is reported here, together
with additional arterial variation encountered in the respective specimen.
The IA originated in the aortic arch on the left side of the trachea, coursed
on that side of the trachea to reach the left thyroid lobe, turned in at a right
angle to pass anterior to the trachea and immediately inferior and parallel to
the thyroid isthmus, and finally it divided inferior to the right thyroid lobe into
the right subclavian and common carotid arteries. The right common carotid
artery immediately turned at a right angle to ascend in the neck. Thus the
terminal branches of the IA had origins in a higher position than is usually
expected. This aberrant course of the IA determined a step-like morphology in
the sagittal plane of the left common carotid artery. Additional variations were
also encountered: (a) a lateralised right external carotid artery with the superior
thyroid artery initially coursing over the internal carotid artery; (b) the right
vertebral artery coursing over the inferior thyroid artery and entering the transverse
process of the fifth cervical vertebra; (c) the left subclavian and vertebral
arteries were tortuous. Knowledge of the presence of this IA variant, with
a transverse subisthmic segment, appears to be important in various surgical
approaches, such as tracheostomies, thyroidectomies, and mediastinoscopies;
in addition, the variations of the IA and the vertebral arteries are relevant for
lower cervical spine approaches. Nevertheless, the lateralised external carotid
artery may lead, if unidentified, to hemorrhagic complications during carotid
space approaches. It is important for surgeons to be aware that if an aberrant IA
is identified it may not be the only variation in that patient. (Folia Morphol 2010;
69, 4: 261-266)
Keywords
trachea; thyroid gland; carotid artery; vertebral artery; brachiocephalic trunk
Title
Transverse subisthmic course of the innominate artery in an adult: detailed anatomy and additional variation
Journal
Folia Morphologica
Issue
Vol 69, No 4 (2010)
Article type
Case report
Pages
261-266
Published online
2010-12-01
Page views
1469
Article views/downloads
1811
Bibliographic record
Folia Morphol 2010;69(4):261-266.
Keywords
trachea
thyroid gland
carotid artery
vertebral artery
brachiocephalic trunk
Authors
M.C. Rusu
A.L. Boscu