Common Carotid Artery 25 



To the right is the innominate artery, and, slightly, the trachea; 

 and to tlie left is the left subclavian artery and the vagus, which in the 

 neck descended along the outer side of the carotid. 



Aneurysm of the common carotid is likely to occur just below 

 its bifurcation. The pulsating tumour might be close by the side of, 

 and be mistaken for, an enlarged lobe of the thyroid ; but there is this 

 manifest distinction between the two: a thyroid tumour moves with the 

 larynx during deglutition, whereas the aneurysmal tumour does not. 

 The pressure effects of the aneurysm may be: upon the internal jugular 

 vein, causing headache, duskiness of the face, and cedema ; upon the 

 superior laryngeal nerve, causing cough; upon the recurrent laryngeal 

 giving rise to hoarseness, laryngeal spasm, or to paralysis of a vocal 

 cord ; upon the sympathetic cord, with the production of dilatation, 

 and, afterwards, of contraction of the pupil. 



Ligation of the common carotid. The subject lies supine, with 

 a block beneath the shoulders, so that as the head is thrown back, and 

 the face is turned to the opposite side, there may be more room, and 

 also that the sterno-mastoid and the other tissues at the front of the 

 neck may be made tense. 



The surgeon then feels for the anterior border of the sterno-mastoid 

 and for the thyroid and cricoid cartilages. With his finger on the cri- 

 coid he knows where the omo-hyoid crosses the sheath. 



To tie the artery above the omo-hyoid, a 3-in., or in a fat subject a 

 4-in., incision is made along the front of the sterno-mastoid, from the 

 level of the upper border of the thyroid cartilage, or even from just 

 below the angle of the jaw, dividing skin, superficial fascia, platysma, 

 and deep fascia. The head is then raised, so that the cord-like edge 

 of the sterno-mastoid may be slackened and drawn outwards. In ap- 

 proaching the sheath a branch to the sterno-mastoid from the superior 

 thyroid will be divided. The descendens noni may be seen and turned 

 aside, and the omo-hyoid maybe pulled downwards. The veins cross- 

 ing the sheath are drawn upwards or downwards, and the sheath is 

 opened on the inner side. 



The aneurysm-needle is passed close to the artery, from without 

 inwards, extreme care being taken not to wound the internal jugular 

 vein, or to include the vagus in the ligature. 



If ligation be required for aneurysm of the upper part of the 

 common carotid, the surgeon must seek the vessel below the omo-hyoid^ 

 where, unfortunately, it is much more deeply placed. He makes an 

 incision along the anterior border of the sterno-mastoid from the 

 cricoid cartilage to the sterno-clavicular joint. The head having been 

 brought forwards, the sterno-mastoid is drawn outwards and the omo- 

 hyoid upwards, the sterno-hyoid and thyroid being drawn inwards. 

 The anterior jugular vein may need attention. If the operation 

 be performed upon the left side, and low down, the internal jugular 

 vein may be found bulging over, or even lying upon the artery. If 



