LIGATION OF THE CAROTID ARTERY. 



97 



it is preferable to confine the patient in laternal recumbency 

 and anaesthetize. 



The operation is made at the same point as for phlebotomy 

 and the same cutaneous wound, a, Plate XVI, may be used 

 for this purpose. The incision should be at least lo cm. 

 long extending through the skin, fleshy panniculus and 

 subscapulo-hyoideus muscles and then a passage forced with 

 the fingers to the trachea. At the region of the neck indi- 

 cated, the carotid passes along the border between the 

 lateral and dorsal surfaces of the trachea, accompanied 

 dorsally by the vagus and sympathetic nerves and ventrally 

 by the recurrent. (In Fig. 2, Plate XVI, the vagus and 

 sympathetic nerves, v and s, are pushed out of their normal 

 position and appear ventrally to the carotid.) Pass the 

 index finger over and behind the carotid until the trachea 

 is reached, and encircling the inner and lower sides of the 

 artery, force a way through the surrounding areolar tissue 

 and draw the vessel out through the wound. As a rule 

 the carotid is still loosely surrounded by connective tissue, 

 which comes from the deep fascia of the neck and in which 

 also the three above mentioned nerves are found. These 

 nerves must be carefully separated from the carotid and 

 must on no account be included in the ligature. Ligate 

 the carotid twice with an interval of about 2 cm. between 

 the two ligatures and divide the artery midway between 

 them. The second ligature is necessary in order to prevent 

 hemorrhage from the distal end through collateral anasto- 

 moses and it is essential to sever the artery in order to avoid 

 its rupture by the stretching of the undivided carotid dur- 

 ing movements of the neck where the nutrition has been 

 cut off at the point of ligation. Provide drainage for the 

 wound and suture the muscle and skin. 



