External Carotid Artery

42  External Carotid Artery


F. Goetz, A. Giesemann


42.1  Bifurcation of the Common Carotid Artery


The division of the common carotid artery has often been related to the larynx. The height of the larynx is age-dependent, resulting in different heights of division of the common carotid artery according to age. It is more reliable to relate the bifurcation to the vertebral column to avoid age dependency. Differences of up to the height of one cervical vertebra have been described between the right and left side. Arch-like divisions are more common in higher divisions and divisions at acute angles more frequent in lower divisions.13


The references are given for anomalies of the carotid arteries in general2,410 (see also Figs. 2.32.28) and for the branches and trunks of the external carotid artery. Many studies deal with more than one branch.1,2,1113



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Fig. 42.1 Bifurcation of the common carotid artery. Schematic (a) and X-ray angiography, unsubtracted image, lateral view, common carotid artery injection (bifurcation at the level of C3) (b). 1 Internal carotid artery; 2 external carotid artery; 3 common carotid artery.


42.2  Superior Thyroid, Lingual, and Facial Arteries


42.2.1  Separate Origins (80%)



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Fig. 42.2 All three arteries originate from the external carotid artery (50%). Schematic (a) and X-ray angiography, lateral view, common carotid artery injection (b). 1 Facial artery; 2 lingual artery; 3 inferior thyroid artery.



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Fig. 42.3 The superior thyroid artery originates from the bifurcation of the common carotid artery (20%). This variation is more common on the left side than on the right side. Schematic (a) and X-ray angiography, lateral view, common carotid artery injection; note ectasia of the superior thyroid and occipital arteries (b). 1 Internal carotid artery; 2 internal maxillary artery; 3 occipital artery; 4 facial artery; 5 inferior thyroid artery.




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Fig. 42.5 The superior thyroid and lingual arteries originate from the common carotid artery (<1%). Schematic.


42.2.2  Trunk Formation (20%)



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Fig. 42.6 Linguofacial trunk (always from the external carotid artery) (18%). The superior thyroid artery might derive from the common carotid artery. Schematic.



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Fig. 42.7 Thyrolingual trunk from the external carotid artery (2%). Schematic.

Oct 29, 2018 | Posted by in CARDIOVASCULAR IMAGING | Comments Off on External Carotid Artery
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